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  • richardmitnick 10:47 am on March 12, 2021 Permalink | Reply
    Tags: "Researchers reveal 3D structure responsible for gene expression", , , , , Med-PIC: Mediator-bound pre-initiation complex, Mediator helps position the rest of the complex — RNA polymerase II and the general transcription factors — at the beginning of genes that the cell wants to transcribe., Northwestern University   

    From Northwestern University: “Researchers reveal 3D structure responsible for gene expression” 

    Northwestern U bloc
    From Northwestern University

    March 11, 2021
    Amanda Morris

    Study marks first time the structure has been visualized in 3D for human cells.

    1
    Image of the human Mediator-bound pre-initiation complex. Credit: Yuan He.

    For the first time ever, a Northwestern University-led research team has peered inside a human cell to view a multi-subunit machine responsible for regulating gene expression.

    Called the Mediator-bound pre-initiation complex (Med-PIC), the structure is a key player in determining which genes are activated and which are suppressed. Mediator helps position the rest of the complex — RNA polymerase II and the general transcription factors — at the beginning of genes that the cell wants to transcribe.

    The researchers visualized the complex in high resolution using cryogenic electron microscopy (cryo-EM), enabling them to better understand how it works. Because this complex plays a role in many diseases, including cancer, neurodegenerative diseases, HIV and metabolic disorders, researchers’ new understanding of its structure could potentially be leveraged to treat disease.

    “This machine is so basic to every branch of modern molecular biology in the context of gene expression,” said Northwestern’s Yuan He, senior author of the study. “Visualizing the structure in 3D will help us answer basic biological questions, such as how DNA is copied to RNA.”

    “Seeing this structure allows us to understand how it works,” added Ryan Abdella, the paper’s co-first author. “It’s like taking apart a common household appliance to see how everything fits together. Now we can understand how the proteins in the complex come together to perform their function.”

    The study was published March 11 in the journal Science. This marks the first time the human Mediator complex has been visualized in 3D in the human cell.

    He is an assistant professor of molecular biosciences in Northwestern’s Weinberg College of Arts and Sciences. Abdella and Anna Talyzina, both graduate students in the He lab, are co-first authors of the paper.

    Famed biochemist Roger Kornberg discovered the Mediator complex in yeast in 1990, a project for which he won the 2006 Nobel Prize in Chemistry. But Mediator comprises a daunting 26 subunits — 56 total when combined with the pre-initiation complex — it’s taken researchers until now to obtain high-resolution images of the human version.

    “It’s a technically quite challenging project,” He said. “These complexes are scarce. It takes hundreds of liters of human cells, which are very hard to grow, to obtain small amounts of the protein complexes.”

    A breakthrough came when He’s team put the sample on a single layer of graphene oxide. By providing this support, the graphene sheet minimized the amount of sample needed for imaging. And compared to the typical support used — amorphous carbon — graphene improved the signal-to-noise ratio for higher-resolution imaging.

    After preparing the sample, the team used cryo-EM, a relatively new technique that won the 2017 Nobel Prize in Chemistry, to determine the 3D shape of proteins, which are often thousands of times smaller than the width of a human hair. The technique works by blasting a stream of electrons at a flash-frozen sample to take many 2D images.

    For this study, He’s team captured hundreds of thousands of images of the Med-PIC complex. They then used computational methods to reconstruct a 3D image.

    “Solving this complex was like assembling a puzzle,” Talyzina said. “Some of those subunits were already known from other experiments, but we had no idea how the pieces assembled together or interacted with each other. With our final structure, we were finally able to see this whole complex and understand its organization.”

    The resulting image shows the Med-PIC complex as a flat, elongated structure, measuring 45 nanometers in length. The researchers also were surprised to discover that the Mediator moves relative to the rest of the complex, binding to RNA polymerase II at a hinge point.

    “Mediator moves like a pendulum,” Abdella said. “Next, we want to understand what this flexibility means. We think it might have an impact on the activity of a key enzyme within the complex.”

    See the full article here .

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    Northwestern South Campus
    South Campus

    Northwestern University(US) is a private research university in Evanston, Illinois. Founded in 1851 to serve the former Northwest Territory, the university is a founding member of the Big Ten Conference.

    On May 31, 1850, nine men gathered to begin planning a university that would serve the Northwest Territory.

    Given that they had little money, no land and limited higher education experience, their vision was ambitious. But through a combination of creative financing, shrewd politicking, religious inspiration and an abundance of hard work, the founders of Northwestern University were able to make that dream a reality.

    In 1853, the founders purchased a 379-acre tract of land on the shore of Lake Michigan 12 miles north of Chicago. They established a campus and developed the land near it, naming the surrounding town Evanston in honor of one of the University’s founders, John Evans. After completing its first building in 1855, Northwestern began classes that fall with two faculty members and 10 students.
    Twenty-one presidents have presided over Northwestern in the years since. The University has grown to include 12 schools and colleges, with additional campuses in Chicago and Doha, Qatar.

    Northwestern is known for its focus on interdisciplinary education, extensive research output, and student traditions. The university provides instruction in over 200 formal academic concentrations, including various dual degree programs. The university is composed of eleven undergraduate, graduate, and professional schools, which include the Kellogg School of Management, the Pritzker School of Law, the Feinberg School of Medicine, the Weinberg College of Arts and Sciences, the Bienen School of Music, the McCormick School of Engineering and Applied Science, the Medill School of Journalism, the School of Communication, the School of Professional Studies, the School of Education and Social Policy, and The Graduate School. As of fall 2019, the university had 21,946 enrolled students, including 8,327 undergraduates and 13,619 graduate students.

    Valued at $12.2 billion, Northwestern’s endowment is among the largest university endowments in the United States. Its numerous research programs bring in nearly $900 million in sponsored research each year.

    Northwestern’s main 240-acre (97 ha) campus lies along the shores of Lake Michigan in Evanston, 12 miles north of Downtown Chicago. The university’s law, medical, and professional schools, along with its nationally ranked Northwestern Memorial Hospital, are located on a 25-acre (10 ha) campus in Chicago’s Streeterville neighborhood. The university also maintains a campus in Doha, Qatar and locations in San Francisco, California, Washington, D.C. and Miami, Florida.

    As of October 2020, Northwestern’s faculty and alumni have included 1 Fields Medalist, 22 Nobel Prize laureates, 40 Pulitzer Prize winners, 6 MacArthur Fellows, 17 Rhodes Scholars, 27 Marshall Scholars, 23 National Medal of Science winners, 11 National Humanities Medal recipients, 84 members of the American Academy of Arts and Sciences, 10 living billionaires, 16 Olympic medalists, and 2 U.S. Supreme Court Justices. Northwestern alumni have founded notable companies and organizations such as the Mayo Clinic, The Blackstone Group, Kirkland & Ellis, U.S. Steel, Guggenheim Partners, Accenture, Aon Corporation, AQR Capital, Booz Allen Hamilton, and Melvin Capital.

    The foundation of Northwestern University can be traced to a meeting on May 31, 1850, of nine prominent Chicago businessmen, Methodist leaders, and attorneys who had formed the idea of establishing a university to serve what had been known from 1787 to 1803 as the Northwest Territory. On January 28, 1851, the Illinois General Assembly granted a charter to the Trustees of the North-Western University, making it the first chartered university in Illinois. The school’s nine founders, all of whom were Methodists (three of them ministers), knelt in prayer and worship before launching their first organizational meeting. Although they affiliated the university with the Methodist Episcopal Church, they favored a non-sectarian admissions policy, believing that Northwestern should serve all people in the newly developing territory by bettering the economy in Evanston.

    John Evans, for whom Evanston is named, bought 379 acres (153 ha) of land along Lake Michigan in 1853, and Philo Judson developed plans for what would become the city of Evanston, Illinois. The first building, Old College, opened on November 5, 1855. To raise funds for its construction, Northwestern sold $100 “perpetual scholarships” entitling the purchaser and his heirs to free tuition. Another building, University Hall, was built in 1869 of the same Joliet limestone as the Chicago Water Tower, also built in 1869, one of the few buildings in the heart of Chicago to survive the Great Chicago Fire of 1871. In 1873 the Evanston College for Ladies merged with Northwestern, and Frances Willard, who later gained fame as a suffragette and as one of the founders of the Woman’s Christian Temperance Union (WCTU), became the school’s first dean of women (Willard Residential College, built in 1938, honors her name). Northwestern admitted its first female students in 1869, and the first woman was graduated in 1874.

    Northwestern fielded its first intercollegiate football team in 1882, later becoming a founding member of the Big Ten Conference. In the 1870s and 1880s, Northwestern affiliated itself with already existing schools of law, medicine, and dentistry in Chicago. Northwestern University Pritzker School of Law is the oldest law school in Chicago. As the university’s enrollments grew, these professional schools were integrated with the undergraduate college in Evanston; the result was a modern research university combining professional, graduate, and undergraduate programs, which gave equal weight to teaching and research. By the turn of the century, Northwestern had grown in stature to become the third largest university in the United States after Harvard University(US) and the University of Michigan(US).

    Under Walter Dill Scott’s presidency from 1920 to 1939, Northwestern began construction of an integrated campus in Chicago designed by James Gamble Rogers, noted for his design of the Yale University(US) campus, to house the professional schools. The university also established the Kellogg School of Management and built several prominent buildings on the Evanston campus, including Dyche Stadium, now named Ryan Field, and Deering Library among others. In the 1920s, Northwestern became one of the first six universities in the United States to establish a Naval Reserve Officers Training Corps (NROTC). In 1939, Northwestern hosted the first-ever NCAA Men’s Division I Basketball Championship game in the original Patten Gymnasium, which was later demolished and relocated farther north, along with the Dearborn Observatory, to make room for the Technological Institute.

    After the golden years of the 1920s, the Great Depression in the United States (1929–1941) had a severe impact on the university’s finances. Its annual income dropped 25 percent from $4.8 million in 1930-31 to $3.6 million in 1933-34. Investment income shrank, fewer people could pay full tuition, and annual giving from alumni and philanthropists fell from $870,000 in 1932 to a low of $331,000 in 1935. The university responded with two salary cuts of 10 percent each for all employees. It imposed hiring and building freezes and slashed appropriations for maintenance, books, and research. Having had a balanced budget in 1930-31, the university now faced deficits of roughly $100,000 for the next four years. Enrollments fell in most schools, with law and music suffering the biggest declines. However, the movement toward state certification of school teachers prompted Northwestern to start a new graduate program in education, thereby bringing in new students and much needed income. In June 1933, Robert Maynard Hutchins, president of the University of Chicago(US), proposed a merger of the two universities, estimating annual savings of $1.7 million. The two presidents were enthusiastic, and the faculty liked the idea; many Northwestern alumni, however, opposed it, fearing the loss of their Alma Mater and its many traditions that distinguished Northwestern from Chicago. The medical school, for example, was oriented toward training practitioners, and alumni feared it would lose its mission if it were merged into the more research-oriented University of Chicago Medical School. The merger plan was ultimately dropped. In 1935, the Deering family rescued the university budget with an unrestricted gift of $6 million, bringing the budget up to $5.4 million in 1938-39. This allowed many of the previous spending cuts to be restored, including half of the salary reductions.

    Like other American research universities, Northwestern was transformed by World War II (1939–1945). Regular enrollment fell dramatically, but the school opened high-intensity, short-term programs that trained over 50,000 military personnel, including future president John F. Kennedy. Northwestern’s existing NROTC program proved to be a boon to the university as it trained over 36,000 sailors over the course of the war, leading Northwestern to be called the “Annapolis of the Midwest.” Franklyn B. Snyder led the university from 1939 to 1949, and after the war, surging enrollments under the G.I. Bill drove dramatic expansion of both campuses. In 1948, prominent anthropologist Melville J. Herskovits founded the Program of African Studies at Northwestern, the first center of its kind at an American academic institution. J. Roscoe Miller’s tenure as president from 1949 to 1970 saw an expansion of the Evanston campus, with the construction of the Lakefill on Lake Michigan, growth of the faculty and new academic programs, and polarizing Vietnam-era student protests. In 1978, the first and second Unabomber attacks occurred at Northwestern University. Relations between Evanston and Northwestern became strained throughout much of the post-war era because of episodes of disruptive student activism, disputes over municipal zoning, building codes, and law enforcement, as well as restrictions on the sale of alcohol near campus until 1972. Northwestern’s exemption from state and municipal property-tax obligations under its original charter has historically been a source of town-and-gown tension.

    Although government support for universities declined in the 1970s and 1980s, President Arnold R. Weber was able to stabilize university finances, leading to a revitalization of its campuses. As admissions to colleges and universities grew increasingly competitive in the 1990s and 2000s, President Henry S. Bienen’s tenure saw a notable increase in the number and quality of undergraduate applicants, continued expansion of the facilities and faculty, and renewed athletic competitiveness. In 1999, Northwestern student journalists uncovered information exonerating Illinois death-row inmate Anthony Porter two days before his scheduled execution. The Innocence Project has since exonerated 10 more men. On January 11, 2003, in a speech at Northwestern School of Law’s Lincoln Hall, then Governor of Illinois George Ryan announced that he would commute the sentences of more than 150 death-row inmates.

    In the 2010s, a 5-year capital campaign resulted in a new music center, a replacement building for the business school, and a $270 million athletic complex. In 2014, President Barack Obama delivered a seminal economics speech at the Evanston campus.

    Organization and administration

    Governance

    Northwestern is privately owned and governed by an appointed Board of Trustees, which is composed of 70 members and, as of 2011, has been chaired by William A. Osborn ’69. The board delegates its power to an elected president who serves as the chief executive officer of the university. Northwestern has had sixteen presidents in its history (excluding interim presidents). The current president, economist Morton O. Schapiro, succeeded Henry Bienen whose 14-year tenure ended on August 31, 2009. The president maintains a staff of vice presidents, directors, and other assistants for administrative, financial, faculty, and student matters. Kathleen Haggerty assumed the role of interim provost for the university in April 2020.

    Students are formally involved in the university’s administration through the Associated Student Government, elected representatives of the undergraduate students, and the Graduate Student Association, which represents the university’s graduate students.

    The admission requirements, degree requirements, courses of study, and disciplinary and degree recommendations for each of Northwestern’s 12 schools are determined by the voting members of that school’s faculty (assistant professor and above).

    Undergraduate and graduate schools

    Evanston Campus:

    Weinberg College of Arts and Sciences (1851)
    School of Communication (1878)
    Bienen School of Music (1895)
    McCormick School of Engineering and Applied Science (1909)
    Medill School of Journalism (1921)
    School of Education and Social Policy (1926)
    School of Professional Studies (1933)

    Graduate and professional

    Evanston Campus

    Kellogg School of Management (1908)
    The Graduate School

    Chicago Campus

    Feinberg School of Medicine (1859)
    Kellogg School of Management (1908)
    Pritzker School of Law (1859)
    School of Professional Studies (1933)

    Northwestern University had a dental school from 1891 to May 31, 2001, when it closed.

    Endowment

    In 1996, Princess Diana made a trip to Evanston to raise money for the university hospital’s Robert H. Lurie Comprehensive Cancer Center at the invitation of then President Bienen. Her visit raised a total of $1.5 million for cancer research.

    In 2003, Northwestern finished a five-year capital campaign that raised $1.55 billion, exceeding its fundraising goal by $550 million.

    In 2014, Northwestern launched the “We Will” campaign with a fundraising goal of $3.75 billion. As of December 31, 2019, the university has received $4.78 billion from 164,026 donors.

    Sustainability

    In January 2009, the Green Power Partnership (sponsored by the EPA) listed Northwestern as one of the top 10 universities in the country in purchasing energy from renewable sources. The university matches 74 million kilowatt hours (kWh) of its annual energy use with Green-e Certified Renewable Energy Certificates (RECs). This green power commitment represents 30 percent of the university’s total annual electricity use and places Northwestern in the EPA’s Green Power Leadership Club. The Initiative for Sustainability and Energy at Northwestern (ISEN), supporting research, teaching and outreach in these themes, was launched in 2008.

    Northwestern requires that all new buildings be LEED-certified. Silverman Hall on the Evanston campus was awarded Gold LEED Certification in 2010; Wieboldt Hall on the Chicago campus was awarded Gold LEED Certification in 2007, and the Ford Motor Company Engineering Design Center on the Evanston campus was awarded Silver LEED Certification in 2006. New construction and renovation projects will be designed to provide at least a 20% improvement over energy code requirements where feasible. At the beginning of the 2008–09 academic year, the university also released the Evanston Campus Framework Plan, which outlines plans for future development of the university’s Evanston campus. The plan not only emphasizes sustainable building construction, but also focuses on reducing the energy costs of transportation by optimizing pedestrian and bicycle access. Northwestern has had a comprehensive recycling program in place since 1990. The university recycles over 1,500 tons of waste, or 30% of all waste produced on campus, each year. All landscape waste at the university is composted.

    Academics

    Education and rankings

    Northwestern is a large, residential research university, and is frequently ranked among the top universities in the United States. The university is a leading institution in the fields of materials engineering, chemistry, business, economics, education, journalism, and communications. It is also prominent in law and medicine. Accredited by the Higher Learning Commission and the respective national professional organizations for chemistry, psychology, business, education, journalism, music, engineering, law, and medicine, the university offers 124 undergraduate programs and 145 graduate and professional programs. Northwestern conferred 2,190 bachelor’s degrees, 3,272 master’s degrees, 565 doctoral degrees, and 444 professional degrees in 2012–2013. Since 1951, Northwestern has awarded 520 honorary degrees. Northwestern also has chapters of academic honor societies such as Phi Beta Kappa (Alpha of Illinois), Eta Kappa Nu, Tau Beta Pi, Eta Sigma Phi (Beta Chapter), Lambda Pi Eta, and Alpha Sigma Lambda (Alpha Chapter).

    The four-year, full-time undergraduate program comprises the majority of enrollments at the university. Although there is no university-wide core curriculum, a foundation in the liberal arts and sciences is required for all majors; individual degree requirements are set by the faculty of each school. The university heavily emphasizes interdisciplinary learning, with 72% of undergrads combining two or more areas of study. Northwestern’s full-time undergraduate and graduate programs operate on an approximately 10-week academic quarter system with the academic year beginning in late September and ending in early June. Undergraduates typically take four courses each quarter and twelve courses in an academic year and are required to complete at least twelve quarters on campus to graduate. Northwestern offers honors, accelerated, and joint degree programs in medicine, science, mathematics, engineering, and journalism. The comprehensive doctoral graduate program has high coexistence with undergraduate programs.

    Despite being a mid-sized university, Northwestern maintains a relatively low student to faculty ratio of 6:1.

    Research

    Northwestern was elected to the Association of American Universities in 1917 and is classified as an R1 university, denoting “very high” research activity. Northwestern’s schools of management, engineering, and communication are among the most academically productive in the nation. The university received $887.3 million in research funding in 2019 and houses over 90 school-based and 40 university-wide research institutes and centers. Northwestern also supports nearly 1,500 research laboratories across two campuses, predominately in the medical and biological sciences.

    Northwestern is home to the Center for Interdisciplinary Exploration and Research in Astrophysics, Northwestern Institute for Complex Systems, Nanoscale Science and Engineering Center, Materials Research Center, Center for Quantum Devices, Institute for Policy Research, International Institute for Nanotechnology, Center for Catalysis and Surface Science, Buffet Center for International and Comparative Studies, the Initiative for Sustainability and Energy at Northwestern, and the Argonne/Northwestern Solar Energy Research Center among other centers for interdisciplinary research.

    Student body

    Northwestern enrolled 8,186 full-time undergraduate, 9,904 full-time graduate, and 3,856 part-time students in the 2019–2020 academic year. The freshman retention rate for that year was 98%. 86% of students graduated after four years and 92% graduated after five years. These numbers can largely be attributed to the university’s various specialized degree programs, such as those that allow students to earn master’s degrees with a one or two year extension of their undergraduate program.

    The undergraduate population is drawn from all 50 states and over 75 foreign countries. 20% of students in the Class of 2024 were Pell Grant recipients and 12.56% were first-generation college students. Northwestern also enrolls the 9th-most National Merit Scholars of any university in the nation.

    In Fall 2014, 40.6% of undergraduate students were enrolled in the Weinberg College of Arts and Sciences, 21.3% in the McCormick School of Engineering and Applied Science, 14.3% in the School of Communication, 11.7% in the Medill School of Journalism, 5.7% in the Bienen School of Music, and 6.4% in the School of Education and Social Policy. The five most commonly awarded undergraduate degrees are economics, journalism, communication studies, psychology, and political science. The Kellogg School of Management’s MBA, the School of Law’s JD, and the Feinberg School of Medicine’s MD are the three largest professional degree programs by enrollment. With 2,446 students enrolled in science, engineering, and health fields, the largest graduate programs by enrollment include chemistry, integrated biology, material sciences, electrical and computer engineering, neuroscience, and economics.

    Athletics

    Northwestern is a charter member of the Big Ten Conference. It is the conference’s only private university and possesses the smallest undergraduate enrollment (the next-smallest member, the University of Iowa, is roughly three times as large, with almost 22,000 undergraduates).

    Northwestern fields 19 intercollegiate athletic teams (8 men’s and 11 women’s) in addition to numerous club sports. 12 of Northwestern’s varsity programs have had NCAA or bowl postseason appearances. Northwestern is one of five private AAU members to compete in NCAA Power Five conferences (the other four being Duke, Stanford, USC, and Vanderbilt) and maintains a 98% NCAA Graduation Success Rate, the highest among Football Bowl Subdivision schools.

    In 2018, the school opened the Walter Athletics Center, a $270 million state of the art lakefront facility for its athletics teams.

    Nickname and mascot

    Before 1924, Northwestern teams were known as “The Purple” and unofficially as “The Fighting Methodists.” The name Wildcats was bestowed upon the university in 1924 by Wallace Abbey, a writer for the Chicago Daily Tribune, who wrote that even in a loss to the University of Chicago, “Football players had not come down from Evanston; wildcats would be a name better suited to “[Coach Glenn] Thistletwaite’s boys.” The name was so popular that university board members made “Wildcats” the official nickname just months later. In 1972, the student body voted to change the official nickname to “Purple Haze,” but the new name never stuck.

    The mascot of Northwestern Athletics is “Willie the Wildcat”. Prior to Willie, the team mascot had been a live, caged bear cub from the Lincoln Park Zoo named Furpaw, who was brought to the playing field on game days to greet the fans. After a losing season however, the team decided that Furpaw was to blame for its misfortune and decided to select a new mascot. “Willie the Wildcat” made his debut in 1933, first as a logo and then in three dimensions in 1947, when members of the Alpha Delta fraternity dressed as wildcats during a Homecoming Parade.

    Traditions

    Northwestern’s official motto, “Quaecumque sunt vera,” was adopted by the university in 1890. The Latin phrase translates to “Whatsoever things are true” and comes from the Epistle of Paul to the Philippians (Philippians 4:8), in which St. Paul admonishes the Christians in the Greek city of Philippi. In addition to this motto, the university crest features a Greek phrase taken from the Gospel of John inscribed on the pages of an open book, ήρης χάριτος και αληθείας or “the word full of grace and truth” (John 1:14).
    Alma Mater is the Northwestern Hymn. The original Latin version of the hymn was written in 1907 by Peter Christian Lutkin, the first dean of the School of Music from 1883 to 1931. In 1953, then Director-of-Bands John Paynter recruited an undergraduate music student, Thomas Tyra (’54), to write an English version of the song, which today is performed by the Marching Band during halftime at Wildcat football games and by the orchestra during ceremonies and other special occasions.
    Purple became Northwestern’s official color in 1892, replacing black and gold after a university committee concluded that too many other universities had used these colors. Today, Northwestern’s official color is purple, although white is something of an official color as well, being mentioned in both the university’s earliest song, Alma Mater (1907) (“Hail to purple, hail to white”) and in many university guidelines.
    The Rock, a 6-foot high quartzite boulder donated by the Class of 1902, originally served as a water fountain. It was painted over by students in the 1940s as a prank and has since become a popular vehicle of self-expression on campus.
    Armadillo Day, commonly known as Dillo Day, is the largest student-run music festival in the country. The festival is hosted every Spring on Northwestern’s Lakefront.
    Primal Scream is held every quarter at 9 p.m. on the Sunday before finals week. Students lean out of windows or gather in courtyards and scream to help relieve stress.
    In the past, students would throw marshmallows during football games, but this tradition has since been discontinued.

    Philanthropy

    One of Northwestern’s most notable student charity events is Dance Marathon, the most established and largest student-run philanthropy in the nation. The annual 30-hour event is among the most widely-attended events on campus. It has raised over $1 million for charity ever year since 2011 and has donated a total of $13 million to children’s charities since its conception.

    The Northwestern Community Development Corps (NCDC) is a student-run organization that connects hundreds of student volunteers to community development projects in Evanston and Chicago throughout the year. The group also holds a number of annual community events, including Project Pumpkin, a Halloween celebration that provides over 800 local children with carnival events and a safe venue to trick-or-treat each year.

    Many Northwestern students participate in the Freshman Urban Program, an initiative for students interested in community service to work on addressing social issues facing the city of Chicago, and the university’s Global Engagement Studies Institute (GESI) programs, including group service-learning expeditions in Asia, Africa, or Latin America in conjunction with the Foundation for Sustainable Development.

    Several internationally recognized non-profit organizations were established at Northwestern, including the World Health Imaging, Informatics and Telemedicine Alliance, a spin-off from an engineering student’s honors thesis.

    Media
    Print

    Established in 1881, The Daily Northwestern is the university’s main student newspaper and is published on weekdays during the academic year. It is directed entirely by undergraduate students and owned by the Students Publishing Company. Although it serves the Northwestern community, the Daily has no business ties to the university and is supported wholly by advertisers.
    North by Northwestern is an online undergraduate magazine established in September 2006 by students at the Medill School of Journalism. Published on weekdays, it consists of updates on news stories and special events throughout the year. It also publishes a quarterly print magazine.
    Syllabus is the university’s undergraduate yearbook. It is distributed in late May and features a culmination of the year’s events at Northwestern. First published in 1885, the yearbook is published by Students Publishing Company and edited by Northwestern students.
    Northwestern Flipside is an undergraduate satirical magazine. Founded in 2009, it publishes a weekly issue both in print and online.
    Helicon is the university’s undergraduate literary magazine. Established in 1979, it is published twice a year: a web issue is released in the winter and a print issue with a web complement is released in the spring.
    The Protest is Northwestern’s quarterly social justice magazine.
    The Northwestern division of Student Multicultural Affairs supports a number of publications for particular cultural groups including Ahora, a magazine about Hispanic and Latino/a culture and campus life; Al Bayan, published by the Northwestern Muslim-cultural Student Association; BlackBoard Magazine, a magazine centered around African-American student life; and NUAsian, a magazine and blog on Asian and Asian-American culture and issues.
    The Northwestern University Law Review is a scholarly legal publication and student organization at Northwestern University School of Law. Its primary purpose is to publish a journal of broad legal scholarship. The Law Review publishes six issues each year. Student editors make the editorial and organizational decisions and select articles submitted by professors, judges, and practitioners, as well as student pieces. The Law Review also publishes scholarly pieces weekly on the Colloquy.
    The Northwestern Journal of Technology and Intellectual Property is a law review published by an independent student organization at Northwestern University School of Law.
    The Northwestern Interdisciplinary Law Review is a scholarly legal publication published annually by an editorial board of Northwestern undergraduates. Its mission is to publish interdisciplinary legal research, drawing from fields such as history, literature, economics, philosophy, and art. Founded in 2008, the journal features articles by professors, law students, practitioners, and undergraduates. It is funded by the Buffett Center for International and Comparative Studies and the Office of the Provost.

    Web-based

    Established in January 2011, Sherman Ave is a humor website that often publishes content on Northwestern student life. Most of its staff writers are current Northwestern undergraduates writing under various pseudonyms. The website is popular among students for its interviews of prominent campus figures, Freshman Guide, and live-tweeting coverage of football games. In Fall 2012, the website promoted a satiric campaign to end the Vanderbilt University football team’s custom of clubbing baby seals.
    Politics & Policy is dedicated to the analysis of current events and public policy. Established in 2010 by students at the Weinberg College of Arts and Sciences, School of Communication, and Medill School of Journalism, the publication reaches students on more than 250 college campuses around the world. Run entirely by undergraduates, it is published several times a week and features material ranging from short summaries of events to extended research pieces. The publication is financed in part by the Buffett Center.
    Northwestern Business Review is a campus source for business news. Founded in 2005, it has an online presence as well as a quarterly print schedule.
    TriQuarterly Online (formerly TriQuarterly) is a literary magazine published twice a year featuring poetry, fiction, nonfiction, drama, literary essays, reviews, blog posts, and art.
    The Queer Reader is Northwestern’s first radical feminist and LGBTQ+ publication.

    Radio, film, and television

    WNUR (89.3 FM) is a 7,200-watt radio station that broadcasts to the city of Chicago and its northern suburbs. WNUR’s programming consists of music (jazz, classical, and rock), literature, politics, current events, varsity sports (football, men’s and women’s basketball, baseball, softball, and women’s lacrosse), and breaking news on weekdays.
    Studio 22 is a student-run production company that produces roughly ten films each year. The organization financed the first film Zach Braff directed, and many of its films have featured students who would later go into professional acting, including Zach Gilford of Friday Night Lights.
    Applause for a Cause is currently the only student-run production company in the nation to create feature-length films for charity. It was founded in 2010 and has raised over $5,000 to date for various local and national organizations across the United States.
    Northwestern News Network is a student television news and sports network, serving the Northwestern and Evanston communities. Its studios and newsroom are located on the fourth floor of the McCormick Tribune Center on Northwestern’s Evanston campus. NNN is funded by the Medill School of Journalism.

     
  • richardmitnick 12:52 pm on January 19, 2021 Permalink | Reply
    Tags: "RNA ties itself in knots then unties itself in mesmerizing video", , , , Julius Lucks and his colleagues generated their videos of RNA using experimental data and a computer algorithm., Learning how RNA tangles and untangles is key to understanding how cells function and how proteins form., , Northwestern University, , RNA — the genetic molecule that tells cells how to build proteins., Snapshots served as individual frames in what would become their final videos of RNA formation., The goal was to zoom in on how RNA forms., The team used a specific kind of RNA called signal recognition particle (SNP) RNA., The team used chemicals to pause the construction process and then recorded how those nucleotides interacted with others already in the lineup.   

    From Northwestern University via Live Science: “RNA ties itself in knots then unties itself in mesmerizing video” 

    Northwestern U bloc
    From Northwestern University

    via

    Live Science

    19 JANUARY 2021
    NICOLETTA LANESE


    RNA folding in action

    1
    © Julius Lucks/Northwestern University.

    Striking new videos show how RNA — the genetic molecule that tells cells how to build proteins — tangles up in insane knots as it forms, only to disentangle itself at the last second, and in a way that took scientists by surprise.

    The high-resolution videos depict a bouncing conga line of nucleotides, the building blocks of RNA; as the single strand of RNA grows longer, these nucleotides dance and twist into different three-dimensional shapes, wiggling first into one conformation and then another. Once fully assembled, the RNA assumes its final shape, which dictates how it can interact with other molecules and proteins in the cell.

    But on the way, the RNA can get trapped in “knots” that must be undone for this final shape to emerge.

    “So the RNA has to get out of it,” said study author Julius Lucks, an associate professor of chemical and biological engineering and a member of the Center for Synthetic Biology at Northwestern University. The RNA won’t function correctly if it remains trapped in the wrong knot, meaning a knot that gets in the way of its final shape, he said. “What was surprising is how it got out of that trap. … This was only discovered when we had the high-resolution videos.”

    In the new study, published Jan. 15 in the journal Molecular Cell, Lucks and his colleagues generated their videos of RNA using experimental data and a computer algorithm. The goal was to zoom in on how RNA forms, both to better understand basic cell biology and to pave the way to better treatments for RNA-related diseases.

    In the experiments, the team used a specific kind of RNA called signal recognition particle (SNP) RNA, an evolutionarily ancient molecule found across all kingdoms of life. They used this RNA as a model since it serves a fundamental function in many kinds of cells.

    To zoom in on how cells build this RNA, the team used chemicals to pause the construction process. So as new nucleotides got added to the RNA, the researchers hit pause and then recorded how those nucleotides interacted with others already in the lineup, and what shapes they all formed together. By capturing the data from many individual RNA molecules, the team developed snapshots of how RNA generally builds itself through time.

    These snapshots served as individual frames in what would become their final videos of RNA formation. That’s where the computer model came in. The algorithm essentially strung together the individual frames into mini-movies and filled in the gaps between frames with the most likely nucleotide interactions. In these videos, the team noticed how the RNA got tangled into complex knots that, if left tied, would render the whole molecule useless.

    “It folds into this trap state, and it kind of stays there,” Lucks said. SNP RNA is meant to form in a signature “hairpin-like” shape, and these traps seem to get in the way. But as more nucleotides get added to the sequence, the new nucleotides swoop in to unravel the knot by displacing the nucleotides tangled up inside.

    “That last little nucleotide is like a trigger” that allows the whole RNA to pop into the correct conformation, Lucks said. Think of the last fold in an origami project, which suddenly transforms a crinkly piece of paper into a lovely butterfly. In the videos, the nucleotides highlighted in dark purple knot themselves up, and the dark pink nucleotides help free them, Lucks noted.

    Learning how RNA tangles and untangles is key to understanding how cells function and how proteins form; the research can also help address diseases where RNA doesn’t function properly or a specific protein can’t form, such as spinal muscular atrophy, and infectious diseases such as COVID-19 that are caused by RNA viruses, according to a statement.

    A big question is whether RNA can mostly untangle itself from these knots, or whether it sometimes needs helper proteins to ease the process. It’s possible that some proteins act as so-called “RNA chaperones” and help sculpt the molecule into its final form, Lucks said. He added that it may be a combination of both, although at this point, that’s speculative.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Northwestern South Campus
    South Campus

    Northwestern is recognized nationally and internationally for its educational programs.

    On May 31, 1850, nine men gathered to begin planning a university that would serve the Northwest Territory.

    Given that they had little money, no land and limited higher education experience, their vision was ambitious. But through a combination of creative financing, shrewd politicking, religious inspiration and an abundance of hard work, the founders of Northwestern University were able to make that dream a reality.

    In 1853, the founders purchased a 379-acre tract of land on the shore of Lake Michigan 12 miles north of Chicago. They established a campus and developed the land near it, naming the surrounding town Evanston in honor of one of the University’s founders, John Evans. After completing its first building in 1855, Northwestern began classes that fall with two faculty members and 10 students.
    Twenty-one presidents have presided over Northwestern in the years since. The University has grown to include 12 schools and colleges, with additional campuses in Chicago and Doha, Qatar.

     
  • richardmitnick 11:27 am on January 17, 2021 Permalink | Reply
    Tags: "The Most Common Stars in Our Galaxy May Be More Habitable Than We Thought", , , , , In terms of flaring activity the Sun is relatively weak compared to some other stars., Low-mass stars live much longer than stars like our Sun meaning there's more time for life to develop on their planets., Northwestern University, Red dwarf stars are the most common kind of star in our neighbourhood and probably in the Milky Way., Red dwarfs are smaller and cooler than our Sun. So that means the habitable zone for any planets orbiting them is smaller and much closer to the star than Earth is to the Sun., , , Some stars especially red dwarfs can flare frequently and violently.   

    From Northwestern University via Science Alert (AU): “The Most Common Stars in Our Galaxy May Be More Habitable Than We Thought” 

    Northwestern U bloc
    From Northwestern University

    via

    ScienceAlert

    Science Alert (AU)

    17 JANUARY 2021
    EVAN GOUGH

    1
    Our Sun’s solar flare, 2 October 2014. Credit: NASA/SDO.

    NASA/SDO.

    Red dwarf stars are the most common kind of star in our neighbourhood, and probably in the Milky Way. Because of that, many of the Earth-like and potentially life-supporting exoplanets we’ve detected are in orbit around red dwarfs. The problem is that red dwarfs can exhibit intense flaring behaviour, much more energetic than our relatively placid Sun.

    So what does that mean for the potential of those exoplanets to actually support life?

    Most life on Earth, and likely on other worlds, relies on stellar energy to survive. The Sun has been the engine for life on Earth since the first cells reproduced. But sometimes, like all stars, the Sun acts up and emits flares.

    Sometimes it emits extremely energetic flares. The powerful magnetic energy in the Sun’s atmosphere becomes unstable, and an enormous amount of energy is released. If it’s released towards Earth, it can cause problems. It can lead to disruptions in radio communications and even blackouts.

    But in terms of flaring activity, the Sun is relatively weak compared to some other stars. Some stars, especially red dwarfs, can flare frequently and violently. A team of researchers studied how flaring activity affects the atmosphere and potential for life on Earth-like planets orbiting low-mass stars, including M-type stars, K-type stars, and G-type stars.

    2
    Art of a flaring red dwarf star, orbited by an exoplanet. Credit: NASA/ESA/G. Bacon/STScI.

    NASA/ESA Hubble Telescope.

    The new study is called Persistence of flare-driven atmospheric chemistry on rocky habitable zone worlds. The lead author is Howard Chen, a PhD student at Northwestern University. The paper is published in the journal Nature Astronomy.

    “Our Sun is more of a gentle giant,” said Allison Youngblood, an astronomer at the University of Colorado at Boulder and co-author of the study.

    “It’s older and not as active as younger and smaller stars. Earth also has a strong magnetic field, which deflects the Sun’s damaging winds.”

    That helps explain why Earth is positively rippling with life as Carl Sagan described our planet. But for planets orbiting low-mass stars like red dwarfs (M-dwarfs) the situation is much different.

    We know that solar flares and associated coronal mass ejections can be very damaging to the prospects of life on unprotected exoplanets. The authors write in their introduction that “[s]tellar activity – which includes stellar flares, coronal mass ejections (CMEs) and stellar proton events (SPEs) – has a profound influence on a planet’s habitability, primarily via its effect on atmospheric ozone.”

    A single flare here and there over time doesn’t have much effect. But many red dwarfs exhibit more frequent and prolonged flaring.

    “We compared the atmospheric chemistry of planets experiencing frequent flares with planets experiencing no flares. The long-term atmospheric chemistry is very different,” said Northwestern’s Howard Chen, the study’s first author, in a press release.

    “Continuous flares actually drive a planet’s atmospheric composition into a new chemical equilibrium.”

    One of the things the team looked at was ozone, and the effect flares have on it. Here on Earth, our ozone layer helps protects us from the Sun’s UV radiation. But extreme flaring activity on red dwarfs can destroy ozone in the atmosphere of planets orbiting close to it.

    When ozone levels drop, a planet is less protected from UV radiation coming from its star. Powerful UV radiation can diminish the possibility of life.


    How could stars help us detect life on other planets?

    In their study, the team used models to help understand flaring and its effects on exoplanet atmospheres. They used flaring data from NASA’s TESS (Transiting Exoplanet Survey Satellite) and long-term exoplanet climate data from other studies.

    NASA/MIT TESS replaced Kepler in search for exoplanets.

    They found some cases where ozone persisted, despite flaring.

    “We’ve found that stellar flares might not preclude the existence of life,” added Daniel Horton, the study’s senior author. “In some cases, flaring doesn’t erode all of the atmospheric ozone. Surface life might still have a fighting chance.”

    2
    This figure from the study shows global-mean vertical profiles of atmospheric species on a simulated planet around a Sun-like G-type star. From left to right are the mixing ratios for ozone, nitrous oxide, nitric acid, and water vapour.Credit: Chen et al, Nature Astronomy, 2020.

    Planets that can support life, at least potentially, can be in a tough spot. They must be close enough to their stars to prevent their water from freezing, but not too close or they’re too hot. But this dance with proximity can expose them to the powerful flares.

    Red dwarfs are smaller and cooler than our Sun, so that means the habitable zone for any planets orbiting them is smaller and much closer to the star than Earth is to the Sun. That not only exposes them to flares but leads to planets being tidally locked to their stars.

    The combination of flaring and tidal-locking can be bad for life’s prospects. Earth’s rotation generates its protective magnetosphere, but tidally-locked planets can’t generate one and are largely unprotected from stellar UV radiation.

    “We studied planets orbiting within the habitable zones of M and K dwarf stars – the most common stars in the universe,” Horton said.

    “Habitable zones around these stars are narrower because the stars are smaller and less powerful than stars like our Sun. On the flip side, M and K dwarf stars are thought to have more frequent flaring activity than our Sun, and their tidally locked planets are unlikely to have magnetic fields helping deflect their stellar winds.”

    3
    This figure from the study shows how repeated stellar flaring can alter the atmospheric gases in a simulated Earth-like planet around a Sun-like star. Credit: Chen et al, 2020.

    There’s a more positive side to this study as well. The team found that flaring activity can actually help the search for life.

    The flares can make it easier to detect some gases which are biomarkers. In this case, they found energy from flaring can highlight the presence of gases like nitric acid, nitrous dioxide, and nitrous oxide, which can all be indicators of living processes.

    4
    This figure from the study shows how repeated stellar flaring can affect the atmospheric chemistry on a modelled Earth-like planet around a K-type star. Note the raised levels of detectable NO, a potential bio-marker. Credit: Chen et al, 2020.

    “Space weather events are typically viewed as a detriment to habitability,” Chen said.

    “But our study quantitatively showed that some space weather can actually help us detect signatures of important gases that might signify biological processes.”

    But only some. In other cases, their work showed that flaring can destroy potential biosignatures from anoxic life.

    “Although we report the 3D effects of stellar flares on oxidizing atmospheres, strong flares could have other unexpected impacts on atmospheres with reducing conditions. For instance, hydrogen oxide species derived from stellar flares could destroy key anoxic biosignatures such as methane, dimethyl sulfide and carbonyl sulfide, thereby suppressing their spectroscopic features,” the authors report.


    Can There Be Life On Planets Around Red Dwarf Stars?

    Another interesting result of this study concerns exoplanet magnetospheres. They find that hyperflares may help reveal the nature and extent of magnetospheres.

    “More speculatively, proton events during hyperflares may reveal the existence of planetary-scale magnetic fields by highlighting particular regions of the planet. By identifying nitrogen- or hydrogen oxide-emitting flux fingerprints during magnetic storms and/or auroral precipitation events, one may be able to determine the geometric extent of exoplanetary magnetospheres.”

    6
    Hyperflares might help us understand the extent of exoplanet magnetospheres by identifying the extent of nitrogen oxide flux fingerprints. Credit: Chen et al, 2020.

    Other recent research has suggested that exoplanets subjected to flaring, especially around red dwarf stars, are not great locations to search for life. The flaring activity is too detrimental. But this study shows that there’s more complexity to the situation.

    Overall it shows that flaring could help us detect biosignatures in some cases. It also shows that while flaring can disrupt exoplanet atmospheres, in many cases they return to normal. It’s also a fact that low-mass stars live much longer than stars like our Sun, meaning there’s more time for life to develop on their planets.

    This new work highlights how complicated the search for life is, and how many variables are involved. And it contains at least one surprise. Whereas flaring has been largely considered detrimental to exoplanet habitability, the fact that it may help detect biosignatures means there’s more going on than expected.

    This research required cooperation from scientists across many disciplines. It relied on climate scientists, astronomers, observers and theorists, and of course, exoplanet scientists.

    “This project was a result of fantastic collective team effort,” said Eric T. Wolf, a planetary scientist at CU Boulder and a co-author of the study.

    “Our work highlights the benefits of interdisciplinary efforts when investigating conditions on extrasolar planets.”

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Northwestern South Campus
    South Campus

    Northwestern is recognized nationally and internationally for its educational programs.

    On May 31, 1850, nine men gathered to begin planning a university that would serve the Northwest Territory.

    Given that they had little money, no land and limited higher education experience, their vision was ambitious. But through a combination of creative financing, shrewd politicking, religious inspiration and an abundance of hard work, the founders of Northwestern University were able to make that dream a reality.

    In 1853, the founders purchased a 379-acre tract of land on the shore of Lake Michigan 12 miles north of Chicago. They established a campus and developed the land near it, naming the surrounding town Evanston in honor of one of the University’s founders, John Evans. After completing its first building in 1855, Northwestern began classes that fall with two faculty members and 10 students.
    Twenty-one presidents have presided over Northwestern in the years since. The University has grown to include 12 schools and colleges, with additional campuses in Chicago and Doha, Qatar.

     
  • richardmitnick 2:28 pm on January 15, 2021 Permalink | Reply
    Tags: "String of stars in Milky Way are related", , , , , Examination of Theia 456 finds its nearly 500 stars were born at same time., Northwestern University, The Milky Way houses 8292 recently discovered stellar streams — all named Theia. But Theia 456 is special.   

    From Northwestern University: “String of stars in Milky Way are related” 

    Northwestern U bloc
    From Northwestern University

    January 15, 2021
    Amanda Morris

    Examination of Theia 456 finds its nearly 500 stars were born at same time.

    1
    An artistic rendering of generic stellar streams in the Milky Way. Credit: NASA/JPL-Caltech/R. Hurt, SSC & Caltech.

    The Milky Way houses 8,292 recently discovered stellar streams — all named Theia. But Theia 456 is special.

    A stellar stream is a rare linear pattern — rather than a cluster — of stars. After combining multiple datasets captured by the Gaia space telescope, a team of astrophysicists found that all of Theia 456’s 468 stars were born at the same time and are traveling in the same direction across the sky.

    “Most stellar clusters are formed together,” said Jeff Andrews, a Northwestern University astrophysicist and member of the team. “What’s exciting about Theia 456 is that it’s not a small clump of stars together. It’s long and stretched out. There are relatively few streams that are nearby, young and so widely dispersed.”

    Andrews presented this research during a virtual press briefing at the 237th meeting of the American Astronomical Society. Theia 456: A New Stellar Association in the Galactic Disk took place today (Jan. 15) as a part of a session on The Modern Milky Way.

    Andrews is a postdoctoral fellow at Northwestern’s Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA). He conducted this work with astrophysicists Marcel Agüeros and Jason Curtis of Columbia University, Julio Chanamé of Pontifica Universidad Catolica, Simon Schuler of University of Tampa and Kevin Covey and Marina Kounkel of Western Washington University.

    While researchers have long known that stars form in groups, most known clusters are spherical in shape. Only recently have astrophysicists started to find new patterns in the sky. They believe long strings of stars were once tight clusters, gradually ripped apart and stretched by tidal forces.

    “As we’ve started to become more advanced in our instrumentation, our technology and our ability to mine data, we’ve found that stars exist in more structures than clumps,” Andrews said. “They often form these streams across the sky. Although we’ve known about these for decades, we’re starting to find hidden ones.”

    Stretching more than 500 light-years, Theia 456 is one of those hidden streams. Because it dwells within the Milky Way’s galactic plane, it’s easily lost within the galaxy’s backdrop of 400 billion stars. Most stellar streams are found elsewhere in the universe — by telescopes pointed away from the Milky Way.

    “We tend to focus our telescopes in other directions because it’s easier to find things,” Andrews said. “Now we’re starting to find these streams in the galaxy itself. It’s like finding a needle in a haystack. Or, in this case, finding a ripple in an ocean.”

    Identifying and examining these structures is a data science challenge. Artificial intelligence algorithms combed huge datasets of stellar data in order to find these structures. Then Andrews developed algorithms to cross-reference those data with pre-existing catalogs of documented stars’ iron abundances.

    Andrews and his team found that the 468 stars within Theia 456 had similar iron abundances, which means that — 100 million years ago — the stars likely formed together. Adding further evidence to this finding, the researchers examined a light curves dataset, which captures how stars’ brightness changes over time.

    “This can be used to measure how fast the stars are spinning,” Agüeros said. “Stars with the same age should show a distinct pattern in their spin rates.”

    With the help of data from NASA’s Transiting Exoplanet Survey Satellite and from the Zwicky Transient Facility — both of which produced light curves for stars in Theia 456 — Andrews and his colleagues were able to determine that the stars in the stream do share a common age.

    The team also found that the stars are moving together in the same direction.

    “If you know how the stars are moving, then you can backtrack to find where the stars came from,” Andrews said. “As we rolled the clock backwards, the stars became closer and closer together. So, we think all these stars were born together and have a common origin.”

    Andrews said combining datasets and data mining is essential to understanding the universe around us.

    “You can only get so far with one dataset,” he said. “When you combine datasets, you get a much richer sense of what’s out there in the sky.”

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Northwestern South Campus
    South Campus

    Northwestern is recognized nationally and internationally for its educational programs.

    On May 31, 1850, nine men gathered to begin planning a university that would serve the Northwest Territory.

    Given that they had little money, no land and limited higher education experience, their vision was ambitious. But through a combination of creative financing, shrewd politicking, religious inspiration and an abundance of hard work, the founders of Northwestern University were able to make that dream a reality.

    In 1853, the founders purchased a 379-acre tract of land on the shore of Lake Michigan 12 miles north of Chicago. They established a campus and developed the land near it, naming the surrounding town Evanston in honor of one of the University’s founders, John Evans. After completing its first building in 1855, Northwestern began classes that fall with two faculty members and 10 students.
    Twenty-one presidents have presided over Northwestern in the years since. The University has grown to include 12 schools and colleges, with additional campuses in Chicago and Doha, Qatar.

     
  • richardmitnick 10:31 am on January 7, 2021 Permalink | Reply
    Tags: "Hostile space weather might not be all bad for exoplanet life", A new study provides some hope for those searching for life beyond Earth., , , , , , , Hostile space weather might even help astronomers detect life on exoplanets around red dwarfs stars., Northwestern University, Red dwarf space weather might decrease our chances of finding exoplanet life., , Space weather can erode the atmospheres of any nearby planets and severely endanger any existing life., Volatile red dwarf stars like Proxima are prone to powerful space weather- that is bursts of radiation caused by flares on these stars.   

    From Northwestern University via EarthSky: “Hostile space weather might not be all bad for exoplanet life” 

    Northwestern U bloc
    From Northwestern University

    via

    1

    EarthSky

    January 6, 2021
    Paul Scott Anderson

    A new study from Northwestern University shows that solar flares – space weather – might not always be as dangerous for life on exoplanets as typically thought. In fact, it might even help astronomers discover alien life on distant worlds.

    1
    Artist’s concept of a distant red dwarf star and accompanying exoplanet. Red dwarfs are common in our galaxy. They produce volatile, deadly flares – and accompanying space weather – that can erode the atmospheres of any nearby planets and severely endanger any existing life. But … maybe not always, according to a new study. Credit: NASA/ ESA/ D. Player (STScI).

    A few days ago, we reported new findings about how space weather spawned by Proxima Centauri, the nearest star to our sun, might inhibit life on Proxima’s planets.

    Centauris Alpha Beta Proxima, 27 February 2012. Skatebiker.

    Volatile red dwarf stars like Proxima are prone to powerful space weather, that is, bursts of radiation caused by flares on these stars.

    4
    On August 31, 2012 a long filament of solar material that had been hovering in the sun’s atmosphere, the corona, erupted out into space at 4:36 p.m. EDT. The coronal mass ejection, or CME, traveled at over 900 miles per second. The CME did not travel directly toward Earth, but did connect with Earth’s magnetic environment, or magnetosphere, causing aurora to appear on the night of Monday, September 3. Pictured here is a lighten blended version of the 304 and 171 angstrom wavelengths taken from the Solar Dynamics Observatory.

    NASA/SDO.

    There are lots of red dwarf stars in our galaxy. So it’s been with some wistfulness that astronomers in recent years have reported that red dwarf space weather might decrease our chances of finding exoplanet life. But science marches on, and now a new study provides some hope for those searching for life beyond Earth. The study suggests that space weather might not always be fatal to life. Hostile space weather might even help astronomers detect life on exoplanets around red dwarfs stars.

    The researchers published the new peer-reviewed findings in Nature Astronomy on December 21, 2020.

    It is known that intense solar flares from red dwarfs or other active stars can erode or even strip the atmospheres from planets that orbit too close. In the case of red dwarfs, these stars are cooler and smaller than the sun, which means such planets are often in the habitable zone, where temperatures are suitable for liquid water on their surfaces. But, they orbit very close to their stars, so they are pummelled by intense radiation. So how could it be that this space weather is not always as bad for life as it is assumed to be?

    It all comes down to chemistry. In the new study, the researchers found that such flares play a significant role in the development of a planet’s atmosphere. Howard Chen, first author of the study, said in a statement:

    “We compared the atmospheric chemistry of planets experiencing frequent flares with planets experiencing no flares. The long-term atmospheric chemistry is very different.”


    How could stars help us detect life on other planets?

    The senior author of the study, Daniel Horton, added:

    “We’ve found that stellar flares might not preclude the existence of life. In some cases, flaring doesn’t erode all of the atmospheric ozone. Surface life might still have a fighting chance.”

    That’s good news for the possibility of life on at least some otherwise potentially habitable worlds orbiting red dwarf stars.

    As Horton further explained:

    “We studied planets orbiting within the habitable zones of M and K dwarf stars, the most common stars in the universe. Habitable zones around these stars are narrower because the stars are smaller and less powerful than stars like our sun. On the flip side, M and K dwarf stars are thought to have more frequent flaring activity than our sun, and their tidally locked planets are unlikely to have magnetic fields helping deflect their stellar winds.”

    The study found that it might be easier in some cases for life to survive around red dwarfs than previously thought, but it, and previous studies, also showed that hostile space weather might even make it easier to detect such life. How?

    If there were gases in a planet’s atmosphere that were a sign of life – such as nitrogen dioxide, nitrous oxide or nitric acid – stellar flares could actually increase their abundance. If such gases were at a very low level and difficult to detect from Earth, flares could increase their amounts to levels that were detectable. It’s an intriguing and ironic possibility, that the same space weather that could extinguish life on a planet might also aid astronomers in detecting life. As Chen explained:

    “Space weather events are typically viewed as a detriment to habitability. But our study quantitatively showed that some space weather can actually help us detect signatures of important gases that might signify biological processes.”

    Chen and his colleagues had also incorporated stellar flare data from NASA’s Transiting Exoplanet Satellite Survey (TESS) mission, launched in 2018, into their model simulations.

    NASA/MIT TESS replaced Kepler in search for exoplanets.

    This helps researchers better understand the overall effects of space weather on exoplanet atmospheres.

    Red dwarf stars are more active than our sun, frequently releasing deadly flares that could erode the atmospheres of planets that orbit too close. The sun has flares, too, of course, but in the case of Earth, our planet’s magnetic field protects us from them. While they might cause problems with power or communications systems, including satellites, they don’t endanger life itself on Earth’s surface. As Allison Youngblood, an astronomer at the University of Colorado Boulder and co-author of the study, described it:

    “Our sun is more of a gentle giant. It’s older and not as active as younger and smaller stars. Earth also has a strong magnetic field, which deflects the sun’s damaging winds.”

    The findings illustrate just how complex the possibility of alien life can be, that it’s not always as straightforward as we might think. It’s not just whether or not a planet is in the habitable zone of a star, for example, but rather there are many factors to consider relating to conditions both on the planet itself as well as its host star. The search for extraterrestrial life requires input from a wide range of scientific disciplines. As Eric T. Wolf, a planetary scientist at the University of Colorado Boulder and a co-author of the study, summed it up:

    “This project was a result of fantastic collective team effort. Our work highlights the benefits of interdisciplinary efforts when investigating conditions on extrasolar planets.”

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Northwestern South Campus
    South Campus

    Northwestern is recognized nationally and internationally for its educational programs.

    On May 31, 1850, nine men gathered to begin planning a university that would serve the Northwest Territory.

    Given that they had little money, no land and limited higher education experience, their vision was ambitious. But through a combination of creative financing, shrewd politicking, religious inspiration and an abundance of hard work, the founders of Northwestern University were able to make that dream a reality.

    In 1853, the founders purchased a 379-acre tract of land on the shore of Lake Michigan 12 miles north of Chicago. They established a campus and developed the land near it, naming the surrounding town Evanston in honor of one of the University’s founders, John Evans. After completing its first building in 1855, Northwestern began classes that fall with two faculty members and 10 students.
    Twenty-one presidents have presided over Northwestern in the years since. The University has grown to include 12 schools and colleges, with additional campuses in Chicago and Doha, Qatar.

     
  • richardmitnick 5:14 pm on December 22, 2020 Permalink | Reply
    Tags: "New electron microscopy technique offers first look at previously hidden processes", , , , Northwestern University, ,   

    From Northwestern University: “New electron microscopy technique offers first look at previously hidden processes” 

    Northwestern U bloc
    From Northwestern University

    December 22, 2020
    Mark Heiden

    1
    A schematic depiction of virtual electron–positron pairs appearing at random near an electron (at lower left). Credit: RJHall/Wikipedia.

    Researchers can now fill in missing information about nanoscale polymerization and “smart” materials for medicine and the environment.

    Northwestern researchers have developed a new microscopy method that allows scientists to see the building blocks of “smart” materials being formed at the nanoscale.

    The chemical process is set to transform the future of clean water and medicines and for the first time people will be able to watch the process in action.

    “Our method allows us to visualize this class of polymerization in real time, at the nanoscale, which has never been done before,” said Northwestern’s Nathan Gianneschi. “We now have the ability to see the reaction taking place, see these nanostructures being formed, and learn how to take advantage of the incredible things they can do.”

    The research was published today (Dec. 22) in the journal Matter.

    The paper is the result of a collaboration between Gianneschi, the associate director of the International Institute for Nanotechnology and the Jacob and Rosalind Cohn Professor of Chemistry in the Weinberg College of Arts and Sciences, and Brent Sumerlin, the George and Josephine Butler Professor of Polymer Chemistry in the College of Liberal Arts & Sciences at the University of Florida.

    Dispersion polymerization is a common scientific process used to make medicines, cosmetics, latex and other items, often on an industrial scale. And at the nanoscale, polymerization can be used to create nanoparticles with unique and valuable properties.

    These nanomaterials hold great promise for the environment, where they can be used to soak up oil spills or other pollutants without harming marine life. In medicine, as the foundation of “smart” drug delivery systems, it can be designed to enter human cells and release therapeutic molecules under specified conditions.

    There have been difficulties in scaling up production of these materials. Initially, production was hampered by the time-consuming process required to create and then activate them. A technique called polymerization-induced self-assembly (PISA) combines steps and saves time, but the molecules’ behavior during this process has proven difficult to predict for one simple reason: Scientists were unable to observe what was actually happening.

    Reactions at the nanoscale are far too small to be seen with the naked eye. Traditional imaging methods can only capture the end result of polymerization, not the process by which it occurs. Scientists have tried to work around this by taking samples at various points in the process and analyzing them, but using only snapshots failed to tell the full story of chemical and physical changes occurring throughout the process.

    “It’s like comparing a few photos of a football game to the information contained in a video of the whole game,” said Gianneschi. “If you understand the pathway by which a chemical forms, if you can see how it occurred, then you can learn how to speed it up, and you can figure out how to perturb the process so you get a different effect.”

    Transmission electron microscopy (TEM) is capable of taking images at a sub-nanometer resolution, but it is generally used for frozen samples, and doesn’t handle chemical reactions as well. With TEM, an electron beam is fired through a vacuum, toward the subject; by studying the electrons that come out the other side, an image can be developed. However, the quality of the image depends on how many electrons are fired by the beam – and firing too many electrons will affect the outcome of the chemical reaction. In other words, it’s a case of the observer effect – watching the self-assembly could alter or even damage the self-assembly. What you end up with is different from what you would have had if you weren’t watching.

    To solve the problem, the researchers inserted the nanoscale polymer materials into a closed liquid cell that would protect the materials from the vacuum inside the electron microscope. These materials were designed to be responsive to changes in temperature, so the self-assembly would begin when the inside of the liquid cell reached a set temperature.

    The liquid cell was enclosed in a silicon chip with small, but powerful, electrodes that serve as heating elements. Embedded in the chip is a tiny window – 200 x 50 nanometers in size – that would allow a low-energy beam to pass through the liquid cell.

    With the chip inserted into the holder of the electron microscope, the temperature inside the liquid cell is raised to 60˚C, initiating the self-assembly. Through the tiny window, the behavior of the block copolymers and the process of formation could be recorded.

    When the process was complete, Gianneschi’s team tested the resulting nanomaterials and found they were the same as comparable nanomaterials produced outside a liquid cell. This confirmed that the technique – which they call variable-temperature liquid-cell transmission electron microscopy (VC-LCTEM) – can be used to understand the nanoscale polymerization process as it occurs under ordinary conditions.

    Of particular interest are the shapes that are generated during polymerization. At different stages the nanoparticles may resemble spheres, worms or jellyfish – each of which confers different properties upon the nanomaterial. By understanding what is happening during self-assembly researchers can begin to develop methods to induce specific shapes and tune their effects.

    “These intricate and well-defined nanoparticles evolve over time, forming and then morphing as they grow,” Sumerlin said. “What’s incredible is that we’re able to see both how and when these transitions occur in real time.”

    Gianneschi believes that insights gained from this technique will lead to unprecedented possibilities for the development and characterization of self-organizing soft matter materials – and scientific disciplines beyond chemistry.

    “We think this can become a tool that’s useful in structural biology and materials science too,” said Gianneschi. “By integrating this with machine learning algorithms to analyze the images, and continuing to refine and improve the resolution, we’re going to have a technique that can advance our understanding of polymerization at the nanoscale and guide the design of nanomaterials that can potentially transform medicine and the environment.”

    Gianneschi is also a professor of biomedical engineering and materials science and engineering in the McCormick School of Engineering. He holds memberships at the Chemistry of Life Processes Institute, Simpson Querrey Institute, and Robert H. Lurie Comprehensive Cancer Center of Northwestern University. Sumerlin is also the acting director of the Center for Macromolecular Science & Engineering at the University of Florida.

    The study received support from the U.S. Department of Defense through the Army Research Office (W911NF-17-1-0326). Additional collaboration came from researchers at the University of California, San Diego.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Northwestern South Campus
    South Campus

    Northwestern is recognized nationally and internationally for its educational programs.

    On May 31, 1850, nine men gathered to begin planning a university that would serve the Northwest Territory.

    Given that they had little money, no land and limited higher education experience, their vision was ambitious. But through a combination of creative financing, shrewd politicking, religious inspiration and an abundance of hard work, the founders of Northwestern University were able to make that dream a reality.

    In 1853, the founders purchased a 379-acre tract of land on the shore of Lake Michigan 12 miles north of Chicago. They established a campus and developed the land near it, naming the surrounding town Evanston in honor of one of the University’s founders, John Evans. After completing its first building in 1855, Northwestern began classes that fall with two faculty members and 10 students.
    Twenty-one presidents have presided over Northwestern in the years since. The University has grown to include 12 schools and colleges, with additional campuses in Chicago and Doha, Qatar.

     
  • richardmitnick 1:04 pm on December 22, 2020 Permalink | Reply
    Tags: "Three flavors are better than one — in ice cream and supernova research", , , , , In a supernova explosion 99% of the dead star’s energy is emitted through neutrinos., , Northwestern University,   

    From Northwestern University: “Three flavors are better than one — in ice cream and supernova research” 

    Northwestern U bloc
    From Northwestern University

    Lila Reynolds
    (413) 461-6314
    lila.reynolds@northwestern.edu

    1

    Any Neapolitan ice cream lover knows three flavors are better than one. New research from Northwestern University has found that by studying all three “flavors” involved in a supernova, they’ve unlocked more clues as to how and why stars die.

    Scientists look at neutrinos (subatomic particles) for critical information about supernova explosions. While previous research identified three “flavors” of neutrinos, many researchers continued to simplify studies on the topic by studying “vanilla” while ignoring “chocolate” and “strawberry.”

    By including all three flavors in the study, Northwestern researchers have developed a deeper knowledge of dying stars and begun to unravel existing hypotheses.

    The study was published Wednesday, Dec. 16, in the journal Physical Review Letters.

    In a supernova explosion, 99% of the dead star’s energy is emitted through neutrinos. Traveling almost at the speed of light and interacting extremely weakly with matter, neutrinos are the first messengers to reach the earth and indicate a star has died.

    Since their initial discovery in the 1950s, particle physicists and astrophysicists have made important strides in understanding, detecting and creating neutrinos. But to limit the complexity of models, many people studying subatomic particles make assumptions to simplify the research – for example, that non-electron neutrinos behave identically when they are propelled from a supernova.

    Part of what makes studying neutrinos so complicated is they come from compact objects (the inside of a star) and then interact with one another, said senior author Manibrata Sen, a postdoctoral researcher currently based at Northwestern under the Network for Neutrinos, Nuclear Astrophysics and Symmetries program at University of California – Berkeley. That means when one flavor is impacted, much like a melting tub of Neapolitan ice cream, its evolution is affected by all others in the system.

    “You can’t create conditions to have neutrinos interacting with each other on Earth,” Sen said. “But in compact objects, you have a very high density of neutrinos. So now each neutrino is interacting with each other because there are so many around.”

    As a result, when an enormous number of neutrinos are sent careening during the massive explosion of a core-collapse supernova, they begin to oscillate. Interactions between neutrinos change the properties and behaviors of the whole system, creating a coupled relationship.

    Therefore, when neutrino density is high, a fraction of neutrinos interchange flavors. When different flavors are emitted in different directions deep within a star, conversions occur rapidly and are called “fast conversions.” Interestingly, the research found that as the number of neutrinos grows, so do their conversion rates, regardless of mass.

    In the study, the scientist created a non-linear simulation of a “fast conversion” when three neutrino flavors are present, where a fast conversion is marked by neutrinos interacting and changing flavors. The researchers removed the assumption that the three flavors of neutrinos — muon, electron and tau neutrinos — have the same angular distribution, giving them each a different distribution.

    A two-flavor setup of the same concept looks at electron neutrinos and “x” neutrinos, in which x can be either muon or tau neutrinos and where differences between the two are insignificant.

    “We’ve shown that they actually are all relevant, and ignoring the presence of muons is not a good strategy,” Sen said. “By including them we show past results are incomplete, and results change drastically when you perform a three-flavor study.”

    While the research could have major implications in both particle and astrophysics, even models used in this research included simplifications. The team hopes to make their results more generic by including spatial dimensions in addition to components of momentum and time.

    In the meantime, Sen said he hopes his team’s research will help the community embrace more complexity in their studies.

    “We are trying to convince the community that when you take these fast conversions into account, you have to use all three flavors to understand it,” he said. “A proper understanding of fast oscillations can actually hold the key to why some stars explode from supernovas.”

    Sen led the research in collaboration with colleagues from the Max Planck Institute for Physics Munich (DE), and the Indian Institute of Technology, Guwahati. The study, “Fast flavor conversions in supernovae: the rise of mu-tau neutrinos,” was supported by the National Science Foundation (award number PHY-1630782). It was also funded by the Heising-Simons Foundation (award number 2017-228).

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Northwestern South Campus
    South Campus

    Northwestern is recognized nationally and internationally for its educational programs.

    On May 31, 1850, nine men gathered to begin planning a university that would serve the Northwest Territory.

    Given that they had little money, no land and limited higher education experience, their vision was ambitious. But through a combination of creative financing, shrewd politicking, religious inspiration and an abundance of hard work, the founders of Northwestern University were able to make that dream a reality.

    In 1853, the founders purchased a 379-acre tract of land on the shore of Lake Michigan 12 miles north of Chicago. They established a campus and developed the land near it, naming the surrounding town Evanston in honor of one of the University’s founders, John Evans. After completing its first building in 1855, Northwestern began classes that fall with two faculty members and 10 students.
    Twenty-one presidents have presided over Northwestern in the years since. The University has grown to include 12 schools and colleges, with additional campuses in Chicago and Doha, Qatar.

     
  • richardmitnick 10:58 pm on December 21, 2020 Permalink | Reply
    Tags: "Volcanic eruptions directly triggered ocean acidification during Early Cretaceous", , During this age in the Early Cretaceous Period -OAE1a- an entire family of sea-dwelling nannoplankton virtually disappeared., , , Nannoplankton and many other marine organisms build their shells out of calcium carbonate., Northwestern researchers examined a 1600-meter-long sediment core taken from the mid-Pacific Mountains., Northwestern University, OAE-oceanic anoxic event, , The Ontong Java Plateau large igneous province (LIP) erupted for seven million years., Thermal ionization mass spectrometry, When atmospheric CO2 dissolves in seawater it forms a weak acid that can inhibit calcium carbonate formation and may even dissolve preexisting carbonate.   

    From Northwestern University: “Volcanic eruptions directly triggered ocean acidification during Early Cretaceous” 

    Northwestern U bloc
    From Northwestern University

    December 21, 2020
    Amanda Morris

    1
    Calcium carbonate samples from a sediment core drilled from the mid-Pacific Mountains.

    Around 120 million years ago, the earth experienced an extreme environmental disruption that choked oxygen from its oceans.

    Known as oceanic anoxic event (OAE) 1a, the oxygen-deprived water led to a minor — but significant — mass extinction that affected the entire globe. During this age in the Early Cretaceous Period, an entire family of sea-dwelling nannoplankton virtually disappeared.

    By measuring calcium and strontium isotope abundances in nannoplankton fossils, Northwestern earth scientists have concluded the eruption of the Ontong Java Plateau large igneous province (LIP) directly triggered OAE1a. Roughly the size of Alaska, the Ontong Java LIP erupted for seven million years, making it one of the largest known LIP events ever. During this time, it spewed tons of carbon dioxide (CO2) into the atmosphere, pushing Earth into a greenhouse period that acidified seawater and suffocated the oceans.

    “We go back in time to study greenhouse periods because Earth is headed toward another greenhouse period now,” said Jiuyuan Wang, a Northwestern Ph.D. student and first author of the study. “The only way to look into the future is to understand the past.”

    The study was published online last week (Dec. 16) in the journal Geology. It is the first study to apply stable strontium isotope measurements to the study of ancient ocean anoxic events.

    Andrew Jacobson, Bradley Sageman and Matthew Hurtgen — all professors of earth and planetary sciences at Northwestern’s Weinberg College of Arts and Sciences — coauthored the paper. Wang is co-advised by all three professors.

    Clues inside cores

    Nannoplankton and many other marine organisms build their shells out of calcium carbonate, which is the same mineral found in chalk, limestone and some antacid tablets. When atmospheric CO2 dissolves in seawater, it forms a weak acid that can inhibit calcium carbonate formation and may even dissolve preexisting carbonate.

    To study the earth’s climate during the Early Cretaceous, the Northwestern researchers examined a 1,600-meter-long sediment core taken from the mid-Pacific Mountains. The carbonates in the core formed in a shallow-water, tropical environment approximately 127 to 100 million years ago and are presently found in the deep ocean.

    “When you consider the Earth’s carbon cycle, carbonate is one of the biggest reservoirs for carbon,” Sageman said. “When the ocean acidifies, it basically melts the carbonate. We can see this process impacting the biomineralization process of organisms that use carbonate to build their shells and skeletons right now, and it is a consequence of the observed increase in atmospheric CO2 due to human activities.”

    Strontium as corroborating evidence

    Several previous studies have analyzed the calcium isotope composition of marine carbonate from the geologic past. The data can be interpreted in a variety of ways, however, and calcium carbonate can change throughout time, obscuring signals acquired during its formation. In this study, the Northwestern researchers also analyzed stable isotopes of strontium — a trace element found in carbonate fossils — to gain a fuller picture.

    “Calcium isotope data can be interpreted in a variety of ways,” Jacobson said. “Our study exploits observations that calcium and strontium isotopes behave similarly during calcium carbonate formation, but not during alteration that occurs upon burial. In this study, the calcium-strontium isotope ‘multi-proxy’ provides strong evidence that the signals are ‘primary’ and relate to the chemistry of seawater during OAE1a.”

    “Stable strontium isotopes are less likely to undergo physical or chemical alteration over time,” Wang added. “Calcium isotopes, on the other hand, can be easily altered under certain conditions.”

    The team analyzed calcium and strontium isotopes using high-precision techniques in Jacobson’s clean laboratory at Northwestern. The methods involve dissolving carbonate samples and separating the elements, followed by analysis with a thermal ionization mass spectrometer.

    Researchers have long suspected that LIP eruptions cause ocean acidification. “There is a direct link between ocean acidification and atmospheric CO2 levels,” Jacobson said. “Our study provides key evidence linking eruption of the Ontong Java Plateau LIP to ocean acidification. This is something people expected should be the case based on clues from the fossil record, but geochemical data were lacking.”

    Modeling future warming

    By understanding how oceans responded to extreme warming and increased atmospheric CO2, researchers can better understand how earth is responding to current, human-caused climate change. Humans are currently pushing the earth into a new climate, which is acidifying the oceans and likely causing another mass extinction.

    “The difference between past greenhouse periods and current human-caused warming is in the timescale,” Sageman said. “Past events have unfolded over tens of thousands to millions of years. We’re making the same level of warming (or more) happen in less than 200 years.”

    “The best way we can understand the future is through computer modeling,” Jacobson added. “We need climate data from the past to help shape more accurate models of the future.”

    The study, “Stable Ca and Sr isotopes support volcanically-triggered biocalcification crisis during Oceanic Anoxic Event 1a,” was supported by the David and Lucile Packard Foundation (award number 2007-31757) and the National Science Foundation (award number EAR-0723151). This work was jump-started with supported from the Ubben Program for Climate and Carbon Science at Northwestern University, which funded previous, related work on the topic.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Northwestern South Campus
    South Campus

    Northwestern is recognized nationally and internationally for its educational programs.

    On May 31, 1850, nine men gathered to begin planning a university that would serve the Northwest Territory.

    Given that they had little money, no land and limited higher education experience, their vision was ambitious. But through a combination of creative financing, shrewd politicking, religious inspiration and an abundance of hard work, the founders of Northwestern University were able to make that dream a reality.

    In 1853, the founders purchased a 379-acre tract of land on the shore of Lake Michigan 12 miles north of Chicago. They established a campus and developed the land near it, naming the surrounding town Evanston in honor of one of the University’s founders, John Evans. After completing its first building in 1855, Northwestern began classes that fall with two faculty members and 10 students.
    Twenty-one presidents have presided over Northwestern in the years since. The University has grown to include 12 schools and colleges, with additional campuses in Chicago and Doha, Qatar.

     
  • richardmitnick 2:00 pm on November 14, 2020 Permalink | Reply
    Tags: "In new step toward quantum tech scientists synthesize ‘bright’ quantum bits", Northwestern University, ,   

    From University of Chicago and Northwestern University: “In new step toward quantum tech scientists synthesize ‘bright’ quantum bits” 

    U Chicago bloc

    From University of Chicago

    and

    Northwestern U bloc
    Northwestern University

    Nov 12, 2020
    Emily Ayshford

    Innovative step by UChicago, Northwestern scientists could boost computing, sensing.

    1
    Graduate student Berk Kovos, postdoctoral scholar Sam Bayliss, and graduate student Peter Mintun (left to right) work on qubit technology in the Awschalom lab in the Pritzker School of Molecular Engineering.

    With their ability to harness the strange powers of quantum mechanics, qubits are the basis for potentially world-changing technologies—like powerful new types of computers or ultra-precise sensors.

    Qubits (short for quantum bits) are often made of the same semiconducting materials as our everyday electronics. But an interdisciplinary team of physicists and chemists at the University of Chicago and Northwestern University has developed a new method to create tailor-made qubits: by chemically synthesizing molecules that encode quantum information into their magnetic, or “spin,” states.

    This new bottom-up approach could ultimately lead to quantum systems that have extraordinary flexibility and control, helping pave the way for next-generation quantum technology.

    “This is a proof-of-concept of a powerful and scalable quantum technology,” said David Awschalom, the Liew Family Professor in Molecular Engineering at University of Chicago’s Pritzker School of Molecular Engineering who led the research along with his colleague Danna Freedman, Professor of Chemistry at Northwestern University. “We can harness the techniques of molecular design to create new atomic-scale systems for quantum information science. Bringing these two communities together will broaden interest and has the potential to enhance quantum sensing and computation.”

    The results were published Nov. 12 in the journal Science.

    Qubits work by harnessing a phenomenon called superposition. While the classical bits used by conventional computers measure either 1 or 0, a qubit can be both 1 and 0 at the same time.

    3
    An interdisciplinary team at the University of Chicago and Northwestern University has developed a way to synthesize tailor-made molecular qubits. Credit: Daniel Laorenza, Northwestern University.

    The team wanted to find a new bottom-up approach to develop molecules whose spin states can be used as qubits, and can be readily interfaced with the outside world. To do so, they used organometallic chromium molecules to create a spin state that they could control with light and microwaves.

    By exciting the molecules with precisely controlled laser pulses and measuring the light emitted, they could “read” the molecules’ spin state after being placed in a superposition—a key requirement for using them in quantum technologies

    By varying just a few different atoms on these molecules through synthetic chemistry, they were also able to modify both their optical and magnetic properties, highlighting the promise for tailor-made molecular qubits.

    “Over the last few decades, optically addressable spins in semiconductors have been shown to be extremely powerful for applications including quantum-enhanced sensing,” said Awschalom, who is also director of the Chicago Quantum Exchange and director of Q-NEXT, a Department of Energy National Quantum Information Science Research Center led by Argonne National Laboratory.

    ANL Q-NEXT

    “Translating the physics of these systems into a molecular architecture opens a powerful toolbox of synthetic chemistry to enable novel functionality that we are only just beginning to explore.”

    “Our results open up a new area of synthetic chemistry. We demonstrated that synthetic control of symmetry and bonding creates qubits that can be addressed in the same way as defects in semiconductors,” Freedman said. “Our bottom-up approach enables both functionalization of individual units as ‘designer qubits’ for target applications and the creation of arrays of readily controllable quantum states, offering the possibility of scalable quantum systems.”

    One potential application for these molecules could be quantum sensors that are designed to target specific molecules. Such sensors could find specific cells within the body, detect when food spoils, or even spot dangerous chemicals.

    This bottom-up approach could also help integrate quantum technologies with existing classical technologies.

    “Some of the challenges facing quantum technologies might be able to be overcome with this very different bottom-up approach,” said Sam Bayliss, a postdoctoral scholar in the Awschalom Group at University of Chicago’s Pritzker School of Molecular Engineering and co first author on the paper. “Using molecular systems in light-emitting diodes was a transformative shift; perhaps something similar could happen with molecular qubits.”

    Daniel Laorenza, a graduate student at Northwestern University and co-first author, sees tremendous potential for chemical innovation in this space. “This chemically specific control over the environment around the qubit provides a valuable feature to integrate optically addressable molecular qubits into a wide range of environments,” he said.

    Other authors on the paper include UChicago graduate students Peter Mintun and Berk Diler Kovos.

    Funding: Office of Naval Research, National Science Foundation, Department of Energy.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Northwestern South Campus
    South Campus

    Northwestern is recognized nationally and internationally for its educational programs.

    On May 31, 1850, nine men gathered to begin planning a university that would serve the Northwest Territory.

    Given that they had little money, no land and limited higher education experience, their vision was ambitious. But through a combination of creative financing, shrewd politicking, religious inspiration and an abundance of hard work, the founders of Northwestern University were able to make that dream a reality.

    In 1853, the founders purchased a 379-acre tract of land on the shore of Lake Michigan 12 miles north of Chicago. They established a campus and developed the land near it, naming the surrounding town Evanston in honor of one of the University’s founders, John Evans. After completing its first building in 1855, Northwestern began classes that fall with two faculty members and 10 students.
    Twenty-one presidents have presided over Northwestern in the years since. The University has grown to include 12 schools and colleges, with additional campuses in Chicago and Doha, Qatar.

    U Chicago Campus

    An intellectual destination

    One of the world’s premier academic and research institutions, the University of Chicago has driven new ways of thinking since our 1890 founding. Today, UChicago is an intellectual destination that draws inspired scholars to our Hyde Park and international campuses, keeping UChicago at the nexus of ideas that challenge and change the world.

    The University of Chicago is an urban research university that has driven new ways of thinking since 1890. Our commitment to free and open inquiry draws inspired scholars to our global campuses, where ideas are born that challenge and change the world.

    We empower individuals to challenge conventional thinking in pursuit of original ideas. Students in the College develop critical, analytic, and writing skills in our rigorous, interdisciplinary core curriculum. Through graduate programs, students test their ideas with UChicago scholars, and become the next generation of leaders in academia, industry, nonprofits, and government.

    UChicago research has led to such breakthroughs as discovering the link between cancer and genetics, establishing revolutionary theories of economics, and developing tools to produce reliably excellent urban schooling. We generate new insights for the benefit of present and future generations with our national and affiliated laboratories: Argonne National Laboratory, Fermi National Accelerator Laboratory, and the Marine Biological Laboratory in Woods Hole, Massachusetts.

    The University of Chicago is enriched by the city we call home. In partnership with our neighbors, we invest in Chicago’s mid-South Side across such areas as health, education, economic growth, and the arts. Together with our medical center, we are the largest private employer on the South Side.

    In all we do, we are driven to dig deeper, push further, and ask bigger questions—and to leverage our knowledge to enrich all human life. Our diverse and creative students and alumni drive innovation, lead international conversations, and make masterpieces. Alumni and faculty, lecturers and postdocs go on to become Nobel laureates, CEOs, university presidents, attorneys general, literary giants, and astronauts.

     
  • richardmitnick 2:14 pm on July 23, 2020 Permalink | Reply
    Tags: "Spectacular ultraviolet flash may finally explain how white dwarfs explode", , , , , For just the second time ever astrophysicists have spotted a spectacular flash of ultraviolet (UV) light accompanying a white dwarf explosion., Northwestern University, Perlmutter Riess and Schmidt proved the accelerating expansion of the universe using Type 1A supernovae., Saul Perlmutter [The Supernova Cosmology Project] Adam Riess and Brian Schmidt [The High-z Supernova Search Team] shared the 2011 Nobel Prize in Physics., SN2019yvq, , ,   

    From Northwestern University: “Spectacular ultraviolet flash may finally explain how white dwarfs explode” 

    Northwestern U bloc
    From Northwestern University

    July 23, 2020

    Amanda Morris
    (847) 467-6790
    amandamo@northwestern.edu

    White dwarf explosion caused extremely rare burst of ultraviolet (UV) light.
    This is just the second time a UV flash accompanied a type Ia supernova.
    White dwarfs are cool objects; UV light requires something incredibly hot.
    Researchers will have a better understanding of how white dwarfs explode as they continue to watch the event throughout the year.

    For just the second time ever, astrophysicists have spotted a spectacular flash of ultraviolet (UV) light accompanying a white dwarf explosion.

    An extremely rare type of supernova, the event is poised to offer insights into several long-standing mysteries, including what causes white dwarfs to explode, how dark energy accelerates the cosmos and how the universe creates heavy metals, such as iron.

    “The UV flash is telling us something very specific about how this white dwarf exploded,” said Northwestern University astrophysicist Adam Miller, who led the research. “As time passes, the exploded material moves farther away from the source. As that material thins, we can see deeper and deeper. After a year, the material will be so thin that we will see all the way into the center of the explosion.”

    At that point, Miller said, his team will know more about how this white dwarf — and all white dwarfs, which are dense remnants of dead stars — explode.

    1
    Zwicky Transient Facility composite image of SN2019yvq (blue dot in the center of the image) in the host galaxy NGC 4441 (large yellow galaxy in the center of the image), which is nearly 140 million light-years away from Earth. SN 2019yvq exhibited a rarely observed ultraviolet flash in the days after the star exploded.
    Credit: ZTF/A. A. Miller (Northwestern University) and D. Goldstein (Caltech)

    Zwicky Transient Facility (ZTF) instrument installed on the 1.2m diameter Samuel Oschin Telescope at Palomar Observatory in California. Courtesy Caltech Optical Observatories

    Caltech Palomar Samuel Oschin 48 inch Telescope, located in San Diego County, California, United States, altitude 1,712 m (5,617 ft)

    The paper was published today (July 23) in The Astrophysical Journal.

    Common event with a rare twist

    Using the Zwicky Transient Facility [above] in California, researchers first spotted the peculiar supernova in December 2019 — just a day after it exploded. The event, dubbed SN2019yvq, occurred in a relatively nearby galaxy located 140 million light-years from Earth, very close to tail of the dragon-shaped Draco constellation.

    Within hours, astrophysicists used NASA’s Neil Gehrels Swift Observatory to study the phenomenon in ultraviolet and X-ray wavelengths.

    NASA Neil Gehrels Swift Observatory

    They immediately classified SN2019yvq as a type Ia (pronounced “one-A”) supernova, a fairly frequent event that occurs when a white dwarf explodes.

    “These are some of the most common explosions in the universe,” Miller said. “But what’s special is this UV flash. Astronomers have searched for this for years and never found it. To our knowledge, this is actually only the second time a UV flash has been seen with a type Ia supernova.”

    Heated mystery

    The rare flash, which lasted for a couple days, indicates that something inside or nearby the white dwarf was incredibly hot. Because white dwarfs become cooler and cooler as they age, the influx of heat puzzled astronomers.

    “The simplest way to create UV light is to have something that’s very, very hot,” Miller said. “We need something that is much hotter than our sun — a factor of three or four times hotter. Most supernovae are not that hot, so you don’t get the very intense UV radiation. Something unusual happened with this supernova to create a very hot phenomenon.”

    Miller and his team believe this is an important clue to understanding why white dwarfs explode, which has been a long-standing mystery in the field. Currently, there are multiple competing hypotheses. Miller is particularly interested in exploring four different hypotheses, which match his team’s data analysis from SN2019yvq.

    Potential scenarios that could cause a white dwarf to explode with a UV flash are:

    A white dwarf consumes material from its companion star and becomes so massive and unstable that it explodes. The white dwarf’s expelled material and the companion star collide, causing a flash of UV emission;
    Extremely hot radioactive material in the white dwarf’s core mixes with its outer layers, causing the outer shell to reach higher temperatures than usual;
    An outer layer of helium ignites carbon within the white dwarf, causing an extremely hot double explosion and a UV flash;
    Two white dwarfs merge, triggering an explosion with colliding ejecta that emit UV radiation.

    “Within a year,” Miller said, “we’ll be able to figure out which one of these four is the most likely explanation.”

    Earth-shattering insights

    Once the researchers know what caused the explosion, they will apply those findings to learn more about planet formation and dark energy.

    Because most of the iron in the universe is created by type Ia supernovae, better understanding this phenomenon could tell us more about our own planet. Iron from exploded stars, for example, formed the core of all rocky planets, including Earth.

    “If you want to understand how the Earth formed, you need to understand where iron came from and how much iron was needed,” Miller said. “Understanding the ways in which a white dwarf explodes gives us a more precise understanding of how iron is created and distributed throughout the universe.”

    Illuminating dark energy

    White dwarfs already play an enormous role in physicists’ current understanding of dark energy as well. Physicists predict that white dwarfs all have the same brightness when they explode. So type Ia supernovae are considered “standard candles,” allowing astronomers to calculate exactly how far the explosions lie from Earth. Using supernovae to measure distances led to the discovery of dark energy, a finding recognized with the 2011 Nobel Prize in Physics.

    _____________________________________________
    4

    4 October 2011

    The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Physics for 2011

    with one half to

    Saul Perlmutter
    The Supernova Cosmology Project
    Lawrence Berkeley National Laboratory and University of California,
    Berkeley, CA, USA

    and the other half jointly to

    Brian P. Schmidt
    The High-z Supernova Search Team
    Australian National University,
    Weston Creek, Australia

    and

    Adam G. Riess
    The High-z Supernova Search Team
    Johns Hopkins University and Space Telescope Science Institute,
    Baltimore, MD, USA

    “for the discovery of the accelerating expansion of the Universe through observations of distant supernovae”

    Saul Perlmutter [The Supernova Cosmology Project] shared the 2006 Shaw Prize in Astronomy, the 2011 Nobel Prize in Physics, and the 2015 Breakthrough Prize in Fundamental Physics with Brian P. Schmidt and Adam Riess [The High-z Supernova Search Team] for providing evidence that the expansion of the universe is accelerating.

    Written in the stars

    “Some say the world will end in fire, some say in ice…” *
    What will be the final destiny of the Universe? Probably it will end in ice, if we are to believe this year’s Nobel Laureates in Physics. They have studied several dozen exploding stars, called supernovae, and discovered that the Universe is expanding at an ever-accelerating rate. The discovery came as a complete surprise even to the Laureates themselves.

    In 1998, cosmology was shaken at its foundations as two research teams presented their findings. Headed by Saul Perlmutter [The Supernova Cosmology Project], one of the teams had set to work in 1988. Brian Schmidt headed another team [The High-z Supernova Search Team], launched at the end of 1994, where Adam Riess was to play a crucial role.

    The research teams raced to map the Universe by locating the most distant supernovae. More sophisticated telescopes on the ground and in space, as well as more powerful computers and new digital imaging sensors (CCD, Nobel Prize in Physics in 2009), opened the possibility in the 1990s to add more pieces to the cosmological puzzle.

    The teams used a particular kind of supernova, called type Ia supernova. It is an explosion of an old compact star that is as heavy as the Sun but as small as the Earth. A single such supernova can emit as much light as a whole galaxy. All in all, the two research teams found over 50 distant supernovae whose light was weaker than expected – this was a sign that the expansion of the Universe was accelerating. The potential pitfalls had been numerous, and the scientists found reassurance in the fact that both groups had reached the same astonishing conclusion.

    For almost a century, the Universe has been known to be expanding as a consequence of the Big Bang about 14 billion years ago. However, the discovery that this expansion is accelerating is astounding. If the expansion will continue to speed up the Universe will end in ice.

    The acceleration is thought to be driven by dark energy, but what that dark energy is remains an enigma – perhaps the greatest in physics today. What is known is that dark energy constitutes about three quarters of the Universe. Therefore the findings of the 2011 Nobel Laureates in Physics have helped to unveil a Universe that to a large extent is unknown to science. And everything is possible again.
    _____________________________________________

    Standard Candles to measure age and distance of the universe from supernovae. NASA

    5
    Evolution of the ultraviolet and visible light emitted from SN2019yvq. Most Type Ia SNe emit far more light in the visible region of the electromagnetic spectrum than in the ultraviolet. As shown here, SN 2019yvq exhibited a spectacular ultraviolet flash just after it exploded. Credit: A. A. Miller/Northwestern University

    “We don’t have a direct way to measure the distance to other galaxies,” Miller explained. “Most galaxies are actually moving away from us. If there is a type Ia supernova in a distant galaxy, we can use it to measure a combination of distance and velocity that allows us to determine the acceleration of the universe. Dark energy remains a mystery. But these supernovae are the best way to probe dark energy and understand what it is.”

    And by better understanding white dwarfs, Miller believes we potentially could better understand dark energy and how fast it causes the universe to accelerate.

    “At the moment, when measuring distances, we treat all of these explosions as the same, yet we have good reason to believe that there are multiple explosion mechanisms,” he said. “If we can determine the exact explosion mechanism, we think we can better separate the supernovae and make more precise distance measurements.”

    The paper, “The spectacular ultraviolet flash from the peculiar type Ia supernova 2019yvq,” was partially supported by the Large Synoptic Survey Telescope Corporation, the Brinson Foundation and the Moore Foundation.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Northwestern South Campus
    South Campus

    Northwestern is recognized nationally and internationally for its educational programs.

    On May 31, 1850, nine men gathered to begin planning a university that would serve the Northwest Territory.

    Given that they had little money, no land and limited higher education experience, their vision was ambitious. But through a combination of creative financing, shrewd politicking, religious inspiration and an abundance of hard work, the founders of Northwestern University were able to make that dream a reality.

    In 1853, the founders purchased a 379-acre tract of land on the shore of Lake Michigan 12 miles north of Chicago. They established a campus and developed the land near it, naming the surrounding town Evanston in honor of one of the University’s founders, John Evans. After completing its first building in 1855, Northwestern began classes that fall with two faculty members and 10 students.
    Twenty-one presidents have presided over Northwestern in the years since. The University has grown to include 12 schools and colleges, with additional campuses in Chicago and Doha, Qatar.

     
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