From Cornell: “New discovery holds potential as tuberculosis drug”

Cornell University

June 27, 2017
Lauren Roberts
cunews@cornell.edu

Story Contacts
Cornell Chronicle
George Lowery
607-255-2171
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Melissa Osgood
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Macrophages infected with M. tuberculosis lipids. Evgeniya Nazarova/Provided

Brian VanderVen, assistant professor of microbiology and immunology, and colleagues at Cornell’s College of Veterinary Medicine, have discovered a key metabolic mechanism in Mycobacterium tuberculosis(Mtb) bacteria, which presents as a novel drug target for potentially treating tuberculosis. The finding is published in the journal eLife.

Mtb, which currently infects nearly 1.5 billion people and causes more than 1 million deaths each year, requires host lipids (cholesterol and fatty acids) to maintain infection. This is considered a defining characteristic of this pathogen, and is thought to support the bacterium’s ability to persist for long periods of time in hosts during both latent and active infections.

However, the mechanisms of how Mtb assimilates the host’s fatty acids has remained a mystery – until now.

Using a genetic screen, VanderVen and his team identified genes involved in cholesterol metabolism. This identified the gene lucA, which encodes a protein of unknown function. To tease out what the protein does, VanderVen’s team created a novel ΔlucA Mtb mutant, which revealed that the protein encoded by the gene, LucA, is an integral membrane protein, and is required for fatty acid and cholesterol uptake in Mtb. Further work determined that LucA interacts with subunits of specific proteins in the Mce1 and Mce4 complexes, which import fatty acids and cholesterol, respectively. Specifically, LucA stabilizes the transporters – acting as an integral linchpin that, if removed, causes Mce1 and Mce4 to fall apart. VanderVen and his research group plan to investigate two other transporters in Mtb – Mce2 and Mce3 – using this same approach.

“Our data highlights the complexities and weaknesses of a highly successful intracellular pathogen,” said VanderVen. The discovery sheds new light on how Mtb metabolizes fatty acids and cholesterol, and also firmly establishes that LucA is required for full virulence of Mtb in vivo, “and is therefore is a novel drug target in Mtb,” said VanderVen.

The next step for VanderVen and his team will be to investigate drugs that inhibit LucA. “This is ideal, because LucA is a bottleneck and inhibiting this protein with a chemical could disable two pathways at a time,” said VanderVen. As it happens, “we already have discovered chemicals that do just that, so the next step will be to begin refining these as potential therapeutics.”

See the full article here .

Please help promote STEM in your local schools.

Stem Education Coalition
Once called “the first American university” by educational historian Frederick Rudolph, Cornell University represents a distinctive mix of eminent scholarship and democratic ideals. Adding practical subjects to the classics and admitting qualified students regardless of nationality, race, social circumstance, gender, or religion was quite a departure when Cornell was founded in 1865.

Today’s Cornell reflects this heritage of egalitarian excellence. It is home to the nation’s first colleges devoted to hotel administration, industrial and labor relations, and veterinary medicine. Both a private university and the land-grant institution of New York State, Cornell University is the most educationally diverse member of the Ivy League.

On the Ithaca campus alone nearly 20,000 students representing every state and 120 countries choose from among 4,000 courses in 11 undergraduate, graduate, and professional schools. Many undergraduates participate in a wide range of interdisciplinary programs, play meaningful roles in original research, and study in Cornell programs in Washington, New York City, and the world over.

From Cornell: “Cornell Tech Announces Winners of Third Annual Startup Awards – May 22, 2017”

Cornell University

May 22, 2017
No writer credit

No image caption or credit.

Cornell Tech awarded four student startup companies $100,000 each in pre-seed funding and one year of free co-working office space in its third annual Startup Awards competition. A panel of tech industry leaders selected the winning student teams, which will be the first Cornell Tech startups to work in The Bridge, Forest City New York’s newly constructed state of the art office space on Cornell Tech’s Roosevelt Island campus, opening September 2017.

“With the Startup Awards, Cornell Tech is able to identify innovative and promising startup ideas coming out of our graduate community, providing them the support and funding needed to kickstart their companies after graduation in the competitive startup ecosystem,” said David Tisch, Head of Startup Studio at Cornell Tech, managing partner of BoxGroup and co-founder of Spring and TechStars NYC.

The Startup Awards grew directly from the culture of entrepreneurship central to the master’s student experience at Cornell Tech. In their final semester, every student enrolls in Startup Studio, where teams of engineering and business students develop their own startup ideas. Cornell Tech created the award program to fill the void for students who have strong prototypes and pitches from their academic work at Cornell Tech, but lack the deep networks and wealth necessary to financially support themselves in the initial phases before seed funding traditionally becomes available. Cornell Tech’s Startup Studio program is run by Tisch and Greg Pass, Cornell Tech’s Chief Entrepreneurial Officer and former Twitter CTO.

“Forest City has been happy to support the Startup Awards, housing the last two cohorts of winners at our New York Times Building. We are thrilled to welcome the first group of graduates’ companies to The Bridge, adding to the unique ecosystem of leading companies – including Two Sigma – working alongside Cornell Tech academic teams,” said MaryAnne Gilmartin, President and CEO of Forest City New York.

This year’s final selected winners were:

SageLink – SageLink connects conversational voice-based applications with marketers to create native and contextual voice ads.
Speech Up – Speech Up is a mobile app that gamifies the speech therapy process to provide an affordable, engaging, and accessible speech therapy platform for kids.
Switch – Switch is an intelligent digital broker that recommends personalized work benefits based on a worker’s gig profile. On-demand coverage lets users save money by insuring themselves only while they are on the job. With quick onboarding, simple terms and effortless claims, freelancers can spend less time covering losses and more time earning money.
Ursa – Ursa is helping product teams build products that users want. Ursa provides collaborative tools that enable 17 million product creatives to capture and analyze user insights for product ideation, design, and validation. followursa.com

More than 30 startups have been formed on the Cornell Tech campus to date, including the Startup Awards, the Runway Startup Postdoc Program at the Jacobs Technion-Cornell Institute, and other alumni. The companies have raised a total of $20 million in pre-seed and seed funding, employ 105 people, and 93% of them are headquartered in NYC.

The Startup Awards winners will work out of the Cornell Tech space at The Bridge on the new Cornell Tech campus opening September 2017. Designed by Weiss/Manfreid architects, The Bridge at Cornell Tech is a first-of-its-kind building that will house an extraordinary mix of cutting-edge companies working alongside groundbreaking Cornell academic teams: from recent Cornell Tech graduates hustling to commercialize a new idea, to start-ups on the verge of explosive growth, and established companies developing leading edge technologies and products. Tech and investment firm Two Sigma was announced as the inaugural tenant and will open a new Collision Lab in the building, where engineers from its R&D team will tackle difficult challenges away from the company’s main campus and interact with innovative start-up companies backed by Two Sigma Ventures, a division of Two Sigma. The Collision Lab will also serve as a tool for Two Sigma to retain and attract the best talent by providing unique access to Cornell Tech’s dynamic ecosystem of innovation. For more information, visit http://www.thebridgeatcornelltech.com.

About Cornell Tech

Cornell Tech brings together faculty, business leaders, tech entrepreneurs, and students in a catalytic environment to reinvent the way we live in the digital age. Cornell Tech’s temporary campus has been up and running at Google’s Chelsea building since 2013, with a growing world-class faculty, and more than 200 masters and Ph.D. students who collaborate extensively with tech-oriented companies and organizations and pursue their own start-ups. Construction is underway on Cornell Tech’s campus on Roosevelt Island, with a first phase due to open in September 2017. When fully completed, the campus will include 2 million square feet of state-of-the-art buildings, over 2 acres of open space, and will be home to more than 2,000 graduate students and hundreds of faculty and staff.

See the full article here .

Please help promote STEM in your local schools.

Stem Education Coalition
Once called “the first American university” by educational historian Frederick Rudolph, Cornell University represents a distinctive mix of eminent scholarship and democratic ideals. Adding practical subjects to the classics and admitting qualified students regardless of nationality, race, social circumstance, gender, or religion was quite a departure when Cornell was founded in 1865.

Today’s Cornell reflects this heritage of egalitarian excellence. It is home to the nation’s first colleges devoted to hotel administration, industrial and labor relations, and veterinary medicine. Both a private university and the land-grant institution of New York State, Cornell University is the most educationally diverse member of the Ivy League.

On the Ithaca campus alone nearly 20,000 students representing every state and 120 countries choose from among 4,000 courses in 11 undergraduate, graduate, and professional schools. Many undergraduates participate in a wide range of interdisciplinary programs, play meaningful roles in original research, and study in Cornell programs in Washington, New York City, and the world over.

From Cornell: “Water forms ‘spine of hydration’ around DNA, group finds”

Cornell University

May 24, 2017
Tom Fleischman
tjf85@cornell.edu

Story Contacts
Cornell Chronicle
Tom Fleischman
607-255-9735
tjf85@cornell.edu

Media Contact
Daryl Lovell
607-254-4799
dal296@cornell.edu

An illustration of what chiral nonlinear spectroscopy reveals: that DNA is surrounded by a chiral water super-structure, forming a “spine of hydration.” Poul Petersen/Provided

Water is the Earth’s most abundant natural resource, but it’s also something of a mystery due to its unique solvation characteristics – that is, how things dissolve in it.

“It’s uniquely adapted to biology, and vice versa,” said Poul Petersen, assistant professor of chemistry and chemical biology. “It’s super-flexible. It dissipates energy and mediates interactions, and that’s becoming more recognized in biological systems.”

How water relates to and interacts with those systems – like DNA, the building block of all living things – is of critical importance, and Petersen’s group has used a relatively new form of spectroscopy to observe a previously unknown characteristic of water.

“DNA’s chiral spine of hydration,” published May 24 in the American Chemical Society journal Central Science, reports the first observation of a chiral water superstructure surrounding a biomolecule. In this case, the water structure follows the iconic helical structure of DNA, which itself is chiral, meaning it is not superimposable on its mirror image. Chirality is a key factor in biology, because most biomolecules and pharmaceuticals are chiral.

“If you want to understand reactivity and biology, then it’s not just water on its own,” Petersen said. “You want to understand water around stuff, and how it interacts with the stuff. And particularly with biology, you want to understand how it behaves around biological material – like protein and DNA.”

Water plays a major role in DNA’s structure and function, and its hydration shell has been the subject of much study. Molecular dynamics simulations have shown a broad range of behaviors of the water structure in DNA’s minor groove, the area where the backbones of the helical strand are close together.

The group’s work employed chiral sum frequency generation spectroscopy (SFG), a technique Petersen detailed in a 2015 paper in the Journal of Physical Chemistry. SFG is a nonlinear optical method in which two photon beams – one infrared and one visible – interact with the sample, producing an SFG beam containing the sum of the two beams’ frequencies, or energies. In this case, the sample was a strand of DNA linked to a silicon-coated prism.

More manipulation of the beams and calculation proved the existence of a chiral water superstructure surrounding DNA.

In addition to the novelty of observing a chiral water structure template by a biomolecule, chiral SFG provides a direct way to examine water in biology.

“The techniques we have developed provide a new avenue to study DNA hydration, as well as other supramolecular chiral structures,” Petersen said.

The group admits that their finding’s biological relevance is unclear, but Petersen thinks the ability to directly examine water and its behavior within biological systems is important.

“Certainly, chemical engineers who are designing biomimetic systems and looking at biology and trying to find applications such as water filtration would care about this,” he said.

Another application, Petersen said, could be in creating better anti-biofouling materials, which are resistant to the accumulation of microorganisms, algae and the like on wetted surfaces.

Collaborators included M. Luke McDermott, Ph.D. ’17; Heather Vanselous, a doctoral student in chemistry and chemical biology and a member of the Petersen Group; and Steven Corcelli, professor of chemistry and biochemistry at the University of Notre Dame.

This work was supported by grants from the National Science Foundation and the Arnold and Mable Beckman Foundation, and made use of the Cornell Center for Materials Research, an NSF Materials Research Science and Engineering Center.

See the full article here .

Please help promote STEM in your local schools.

Stem Education Coalition
Once called “the first American university” by educational historian Frederick Rudolph, Cornell University represents a distinctive mix of eminent scholarship and democratic ideals. Adding practical subjects to the classics and admitting qualified students regardless of nationality, race, social circumstance, gender, or religion was quite a departure when Cornell was founded in 1865.

Today’s Cornell reflects this heritage of egalitarian excellence. It is home to the nation’s first colleges devoted to hotel administration, industrial and labor relations, and veterinary medicine. Both a private university and the land-grant institution of New York State, Cornell University is the most educationally diverse member of the Ivy League.

On the Ithaca campus alone nearly 20,000 students representing every state and 120 countries choose from among 4,000 courses in 11 undergraduate, graduate, and professional schools. Many undergraduates participate in a wide range of interdisciplinary programs, play meaningful roles in original research, and study in Cornell programs in Washington, New York City, and the world over.

From Cornell: “Weill Cornell team creates breakthrough on blood disorders”

Cornell University

May 18, 2017
Geri Clark
cunews@cornell.edu

Story Contacts
Cornell Chronicle
George Lowery
607-255-2171
gpl5@cornell.edu

Media Contact
Jennifer Gundersen
646-962-9497
jeg2034@med.cornell.edu

This image shows reprogrammed hematopoietic stem cells (green) that are arising from mouse cells. These stem cells are developing close to a group of cells, called the vascular niche cells (gray), which provides them with the nurturing factors necessary for the reprogramming. Dr. Raphael Lis/Provided

Researchers at Weill Cornell Medicine have discovered an innovative method to make an unlimited supply of healthy blood cells from the readily available cells that line blood vessels. This achievement marks the first time any research group has generated such blood-forming stem cells.

“This is a game-changing breakthrough that brings us closer not only to treat blood disorders, but also deciphering the complex biology of stem-cell self-renewal machinery,” said senior author Dr. Shahin Rafii, director of the Ansary Stem Cell Institute, chief of the Division of Regenerative Medicine and the Arthur B. Belfer Professor at Weill Cornell Medicine.

“This is exciting because it provides us with a path toward generating clinically useful quantities of normal stem cells for transplantation that may help us cure patients with genetic and acquired blood diseases,” added co-senior author Dr. Joseph Scandura, associate professor of medicine and scientific director of the Silver Myeloproliferative Neoplasms Center at Weill Cornell Medicine.

Hematopoietic stem cells (HSCs) are long-lasting cells that mature into white blood cells, red blood cells and platelets. Billions of circulating blood cells do not survive long in the body and must be continuously replenished. When this does not happen, severe blood diseases, such as anemia, bleeding or life-threatening infections, can occur. A special property of HSCs is that they can also “self-renew” to form more HSCs. This property allows just a few thousand HSCs to produce all of the blood cells a person has throughout his or her life.

Researchers have long hoped to find a way to make the body produce healthy HSCs to cure these diseases. But this has never been accomplished, in part because scientists have been unable to engineer a nurturing environment within which stem cells can convert into new, long-lasting cells – until now.

In a paper published May 17 in Nature, Rafii and his colleagues demonstrate a way to efficiently convert cells that line all blood vessels, called vascular endothelial cells, into abundant, fully functioning HSCs that can be transplanted to yield a lifetime supply of new, healthy blood cells. The research team also discovered that specialized types of endothelial cells serve as that nurturing environment, known as vascular niche cells, and they choreograph the new converted HSCs’ self-renewal. This finding may solve one of the most long-standing questions in regenerative and reproductive medicine: How do stem cells constantly replenish their supply?

The research team showed in a 2014 Nature study that converting adult human vascular endothelial cells into hematopoietic cells was feasible. However, the team was unable to prove that they had generated true HSCs because human HSCs’ function and regenerative potential can only be approximated by transplanting the cells into mice, which don’t truly mimic human biology.

To address this issue, the team applied their conversion approach to mouse blood marrow transplant models that are endowed with normal immune function and where definitive evidence for HSC potential could rigorously tested. The researchers took vascular endothelial cells isolated from readily accessible adult mice organs and instructed them to overproduce certain proteins associated with blood stem-cell function. These reprogrammed cells were grown and multiplied in co-culture with the engineered vascular niche. The reprogrammed HSCs were then transplanted as single cells with their progenies into mice that had been irradiated to destroy all of their blood-forming and immune systems, and then monitored to see whether or not they would self-renew and produce healthy blood cells.

Study co-authors, from left: Dr. Joseph Scandura, Dr. Raphael Lis, Dr. Jason Butler, Michael Poulos, Balvir Kunar Jr., Chaitanya R. Badwe, Koji Shido, Dr. Zev Rozenwaks, Jose-Gabriel Barcia-Duran, Dr. Shahin Rafii and Dr. Jenny Xiang. Not pictured: Charles Karrasch, David Redmond, Dr. Will Schachterle, Michael Ginsberg, Dr. Arash Rafii and Dr. Olivier Elemento. Michael Gutkin’Provided

The conversion procedure yielded a plethora of transplantable HSCs that regenerated the entire blood system in mice for the duration of their life spans, a phenomenon known as engraftment. “We developed a fully functioning and long-lasting blood system,” said lead author Raphael Lis, an instructor in medicine and reproductive medicine at Weill Cornell Medicine. In addition, the HSC-engrafted mice developed all of the working components of the immune systems. “This is clinically important because the reprogrammed cells could be transplanted to allow patients to fight infections after marrow transplants,” Lis said. The mice in the study went on to live normal-length lives and die natural deaths, with no sign of leukemia or any other blood disorders.

In collaboration with Olivier Elemento, associate director of the HRH Prince Alwaleed Bin Talal Bin Abdulaziz Al-Saud Institute for Computational Biomedicine, and Dr. Jenny Xiang, director of Genomics Services, Rafii and his team also showed the reprogrammed HSCs and their differentiated progenies – including white and red bloods cells, as well as the immune cells – were endowed with the same genetic attributes as that of normal adult stem cells. These findings suggest the reprogramming process results in the generation of true HSCs that have genetic signatures that are very similar to normal adult HSCs.

The Weill Cornell Medicine team is the first to achieve cellular reprogramming to create engraftable and authentic HSCs, which have been considered the holy grail of stem cell research. “We think the difference is the vascular niche,” said contributing author Jason Butler, assistant professor of regenerative medicine at Weill Cornell Medicine. “Growing stem cells in the vascular niche puts them back into context, where they come from and multiply. We think this is why we were able to get stem cells capable of self-renewing.”

If this method can be scaled up and applied to humans, it could have wide-ranging clinical implications. “It might allow us to provide healthy stem cells to patients who need bone marrow donors but have no genetic match,” Scandura said. “It could lead to new ways to cure leukemia and myeloproliferative neoplasms, and may help us correct genetic defects that cause blood diseases like sickle-cell anemia.”

“More importantly, our vascular niche-stem-cell expansion model may be employed to clone the key unknown growth factors produced by this niche that are essential for self-perpetuation of stem cells,” Rafii said. “Identification of those factors could be important for unraveling the secrets of stem cells’ longevity and translating the potential of stem cell therapy to the clinical setting.”

Additional study co-authors include Charles Karrasch, Michael Poulos, Balvir Kunar, David Redmond, Jose-Gabriel Barcia-Duran, Chaitanya Badwe and Koji Shido of Weill Cornell Medicine; Will Schachterle, formerly of Weill Cornell Medicine; Dr. Arash Rafii of Weill Cornell Medicine-Qatar; Dr. Michael Ginsberg of Angiocrine Bioscience; and Dr. Nancy Speck of the Abramson Family Cancer Research Institute in the Perelman School of Medicine at the University of Pennsylvania.

Various study authors have relationships with Angiocrine Bioscience that are independent of Weill Cornell Medicine.

See the full article here .

Please help promote STEM in your local schools.

Stem Education Coalition
Once called “the first American university” by educational historian Frederick Rudolph, Cornell University represents a distinctive mix of eminent scholarship and democratic ideals. Adding practical subjects to the classics and admitting qualified students regardless of nationality, race, social circumstance, gender, or religion was quite a departure when Cornell was founded in 1865.

Today’s Cornell reflects this heritage of egalitarian excellence. It is home to the nation’s first colleges devoted to hotel administration, industrial and labor relations, and veterinary medicine. Both a private university and the land-grant institution of New York State, Cornell University is the most educationally diverse member of the Ivy League.

On the Ithaca campus alone nearly 20,000 students representing every state and 120 countries choose from among 4,000 courses in 11 undergraduate, graduate, and professional schools. Many undergraduates participate in a wide range of interdisciplinary programs, play meaningful roles in original research, and study in Cornell programs in Washington, New York City, and the world over.

From Cornell: “Critical Thinking—Attained through Physics”

Cornell University

5.23.17
Jackie Swift

Beatrice Jin

Science is about experimentation, creativity, even play. The greatest breakthroughs have come from those who pushed the known limits to ask why, how, and ultimately what if. If this is how the best science is done, then why don’t we start giving students autonomy to explore and create in the lab early in their university training? If we do, Natasha G. Holmes, Physics, says that perhaps they’ll get a taste of what it means to be a scientist early enough that they’ll choose science as a career path.

Holmes studies the teaching and learning of physics, especially in lab courses, but her work is applicable more broadly across many disciplines. “In the lab students have their hands on the equipment,” she says. “I’m looking at what they are getting or not getting out of that experience and also digging into what the lab space is actually good for. As a loftier, long-term goal, how can we provide students with transferable skills that will make them critical thinkers and good citizens?”

A Tool for Assessing Critical Thinking Skills in Physics

To shed light on those questions, Holmes is working on a project funded by the National Science Foundation to design a tool that can assess critical thinking. “This will be a closed response standardized test that allows any instructor to measure whether their students can think critically about a physics experiment,” Holmes says.

Holmes and her coresearcher, Carl Wieman of Stanford University, began designing the assessment by gathering initial data from respondents at multiple universities. They asked them a series of open-ended questions about an introductory level mass-on-a-spring physics experiment conducted by a hypothetical group of people. Respondents answered questions about the hypothetical group’s methods and the data that the group collected. For instance, they were asked if they thought the data collected was reasonable, how well they felt the hypothetical group designed the experiment, and how well the group evaluated the model.

“We were looking for the most common answers an introductory physics student would give,” Holmes explains. “But we also wanted to collect as many responses as we could from advanced physics majors, professors, and grad students to see the full spectrum of possible answers.” The researchers distilled the open-ended answers down into a multiple-choice test that can be given to students before they take a lab course and again afterward, to see how well they have learned the concepts.

See the full article here .

Please help promote STEM in your local schools.

Stem Education Coalition
Once called “the first American university” by educational historian Frederick Rudolph, Cornell University represents a distinctive mix of eminent scholarship and democratic ideals. Adding practical subjects to the classics and admitting qualified students regardless of nationality, race, social circumstance, gender, or religion was quite a departure when Cornell was founded in 1865.

Today’s Cornell reflects this heritage of egalitarian excellence. It is home to the nation’s first colleges devoted to hotel administration, industrial and labor relations, and veterinary medicine. Both a private university and the land-grant institution of New York State, Cornell University is the most educationally diverse member of the Ivy League.

On the Ithaca campus alone nearly 20,000 students representing every state and 120 countries choose from among 4,000 courses in 11 undergraduate, graduate, and professional schools. Many undergraduates participate in a wide range of interdisciplinary programs, play meaningful roles in original research, and study in Cornell programs in Washington, New York City, and the world over.

From Cornell: “New electron microscope sees more than an image”

Cornell University

March 30, 2017
Bill Steele
ws21@cornell.edu

Sol Gruner, left, professor of physics, and David Muller, professor of applied and engineering physics. Chris Kitchen/University Photography

. Their electron microscope pixel array detector (EMPAD) yields not just an image, but a wealth of information about the electrons that create the image and, from that, more about the structure of the sample.

“We can extract local strains, tilts, rotations, polarity and even electric and magnetic fields,” explained David Muller, professor of applied and engineering physics, who developed the new device with Sol Gruner, professor of physics, and members of their research groups.

Cornell’s Center for Technology Licensing (CTL) has licensed the invention to FEI, a leading manufacturer of electron microscopes (a division of Thermo Fisher Scientific, which supplies products and services for the life sciences through several brands). FEI expects to complete the commercialization of the design and offer the detector for new and retrofitted electron microscopes this year.

“It’s mind-boggling to contemplate what researchers around the world will discover through this match of Cornell’s deep expertise in detector science with market leader Thermo Fisher Scientific,” said Patrick Govang, technology licensing officer at CTL.

The scientists described their work in the February 2016 issue of the journal Microscopy and Microanalysis.

In the usual scanning transmission electron microscope (STEM), a narrow beam of electrons is fired down through a sample, scanning back and forth to produce an image. A detector underneath reads the varying intensity of electrons coming through and sends a signal that draws an image on a computer screen.

The EMPAD that replaces the usual detector is made up of a 128×128 array of electron-sensitive pixels, each 150 microns (millionths of a meter) square, bonded to an integrated circuit that reads out the signals – somewhat like the array of light-sensitive pixels in the sensor in a digital camera, but not to form an image. Its purpose is to detect the angles at which electrons emerge, as each electron hits a different pixel. The EMPAD is a spinoff of X-ray detectors the physicists have built for X-ray crystallography work at the Cornell High Energy Synchrotron Source (CHESS), and it can work in a similar way to reveal the atomic structure of a sample.

Combined with the focused beam of the electron microscope, the detector allows researchers to build up a “four-dimensional” map of both position and momentum of the electrons as they pass through a sample to reveal the atomic structure and forces inside. The EMPAD is unusual in its speed, sensitivity and wide range of intensities it can record – from detecting a single electron to intense beams containing hundreds of thousands or even a million electrons.

“It would be like taking a photograph of a sunset that showed both details on the surface of the sun and the details of darkest shadows,” Muller explained.

See the full article here .

Please help promote STEM in your local schools.

Stem Education Coalition
Once called “the first American university” by educational historian Frederick Rudolph, Cornell University represents a distinctive mix of eminent scholarship and democratic ideals. Adding practical subjects to the classics and admitting qualified students regardless of nationality, race, social circumstance, gender, or religion was quite a departure when Cornell was founded in 1865.

Today’s Cornell reflects this heritage of egalitarian excellence. It is home to the nation’s first colleges devoted to hotel administration, industrial and labor relations, and veterinary medicine. Both a private university and the land-grant institution of New York State, Cornell University is the most educationally diverse member of the Ivy League.

On the Ithaca campus alone nearly 20,000 students representing every state and 120 countries choose from among 4,000 courses in 11 undergraduate, graduate, and professional schools. Many undergraduates participate in a wide range of interdisciplinary programs, play meaningful roles in original research, and study in Cornell programs in Washington, New York City, and the world over.

From Cornell: “Volcanic hydrogen spurs chances of finding exoplanet life”

Cornell University

February 27, 2017
Blaine Freidlander

(Photo : Wikimedia Commons/E. Klett, U.S. Fish and Wildlife Service)

Hunting for habitable exoplanets now may be easier: Cornell astronomers report that hydrogen pouring from volcanic sources on planets throughout the universe could improve the chances of locating life in the cosmos.

Planets located great distances from stars freeze over. “On frozen planets, any potential life would be buried under layers of ice, which would make it really hard to spot with telescopes,” said lead author Ramses Ramirez, research associate at Cornell’s Carl Sagan Institute. “But if the surface is warm enough – thanks to volcanic hydrogen and atmospheric warming – you could have life on the surface, generating a slew of detectable signatures.”

Combining the greenhouse warming effect from hydrogen, water and carbon dioxide on planets sprinkled throughout the cosmos, distant stars could expand their habitable zones by 30 to 60 percent, according to this new research. “Where we thought you would only find icy wastelands, planets can be nice and warm – as long as volcanoes are in view,” said Lisa Kaltenegger, Cornell professor of astronomy and director of the Carl Sagan Institute.

Ramses Ramirez, research associate at Cornell’s Carl Sagan Institute, left, and Lisa Kaltenegger, professor of astronomy and director of the Sagan Institute.

Their research, “A Volcanic Hydrogen Habitable Zone,” is published today in The Astrophysical Journal Letters.

The idea that hydrogen can warm a planet is not new, but an Earth-like planet cannot hold onto its hydrogen for more than a few million years. Volcanoes change the concept.

“You get a nice big warming effect from volcanic hydrogen, which is sustainable as long as the volcanoes are intense enough,” said Ramirez, who suggested the possibility that these planets may sustain detectable life on their surface.

A very light gas, hydrogen also “puffs up” planetary atmospheres, which will likely help scientists detect signs of life. “Adding hydrogen to the air of an exoplanet is a good thing if you’re an astronomer trying to observe potential life from a telescope or a space mission. It increases your signal, making it easier to spot the makeup of the atmosphere as compared to planets without hydrogen,” said Ramirez.

In our solar system, the habitable zone extends to 1.67 times the Earth-sun distance, just beyond the orbit of Mars. With volcanically sourced hydrogen on planets, this could extend the solar system’s habitable zone reach to 2.4 times the Earth-sun distance – about where the asteroid belt is located between Mars and Jupiter. This research places a lot of planets that scientists previously thought to be too cold to support detectable life back into play.

“We just increased the width of the habitable zone by about half, adding a lot more planets to our ‘search here’ target list,” said Ramirez.

Stellar temperature versus distance from the star compared to Earth for the classic habitable zone (shaded blue) and the volcanic habitable zone extension (shaded red). Credit: Ramses Ramirez

Atmospheric biosignatures, such as methane in combination with ozone – indicating life – will likely be detected by the forthcoming, next-generation James Webb Space Telescope, launching in 2018, or the approaching European Extremely Large Telescope, first light in 2024.

NASA reported Feb. 22 finding seven Earth-like planets around the star Trappist-1. “Finding multiple planets in the habitable zone of their host star is a great discovery because it means that there can be even more potentially habitable planets per star than we thought,” said Kaltenegger. “Finding more rocky planets in the habitable zone – per star – increases our odds of finding life.”

With this latest research, Ramirez and Kaltenegger have possibly added to that number by showing that habitats can be found, even those once thought too cold, as long as volcanoes spew enough hydrogen. Such a volcanic hydrogen habitable zone might just make the Trappist-1 system contain four habitable zone planets, instead of three. “Although uncertainties with the orbit of the outermost Trappist-1 planet ‘h’ means that we’ll have to wait and see on that one,” said Kaltenegger.

The Simons Foundation and the Cornell Center for Astrophysics and Planetary Science funded this research.

See the full article here .

Please help promote STEM in your local schools.

Stem Education Coalition
Once called “the first American university” by educational historian Frederick Rudolph, Cornell University represents a distinctive mix of eminent scholarship and democratic ideals. Adding practical subjects to the classics and admitting qualified students regardless of nationality, race, social circumstance, gender, or religion was quite a departure when Cornell was founded in 1865.

Today’s Cornell reflects this heritage of egalitarian excellence. It is home to the nation’s first colleges devoted to hotel administration, industrial and labor relations, and veterinary medicine. Both a private university and the land-grant institution of New York State, Cornell University is the most educationally diverse member of the Ivy League.

On the Ithaca campus alone nearly 20,000 students representing every state and 120 countries choose from among 4,000 courses in 11 undergraduate, graduate, and professional schools. Many undergraduates participate in a wide range of interdisciplinary programs, play meaningful roles in original research, and study in Cornell programs in Washington, New York City, and the world over.

From Cornell: “Slo-mo unwrapping of nucleosomal DNA probes protein’s role”

Cornell University

Jan. 11, 2017
Tom Fleischman

Using X-rays to visualize DNA (dark gray) and fluorescence to monitor the histone proteins (yellow and cyan), Cornell researchers led by professor and director of applied and engineering physics Lois Pollack found that the release of histone proteins is guided by unwrapping DNA. Joshua Tokuda/Provided

Nucleosomes are tightly packed bunches of DNA and protein which, when linked together as chromatin, form each of the 46 chromosomes found in human cells.

The organization of DNA in nucleosomes is important not just for DNA packaging; it also forms the basis for the regulation of gene expression. By controlling the access to DNA, nucleosomes help facilitate all kinds of gene activity, from RNA transcription to DNA replication and repair.

A research group led by Lois Pollack, professor of applied and engineering physics, used a combination of X-ray and fluorescence-based approaches to study how the shapes and compositions of nucleosomes change after being destabilized.

The group’s paper, Asymmetric unwrapping of nucleosomal DNA propagates asymmetric opening and dissociation of the histone core, is published online in Proceedings of the National Academy of Sciences. Co-lead authors are postdoctoral researcher Yujie Chen and doctoral student Joshua Tokuda.

Using FRET, small-angle X-ray scattering and other methods, the group was able to get a clear picture of the DNA activity during unwrapping of the histone core. It was found that different DNA shapes were produced during the unwrapping process, most notably a “teardrop” shape that seemed to promote protein activity.

The histone core goes from eight protein molecules to six when the DNA unwraps into the teardrop shape. “It’s as if having the DNA in this shape is a signal to the protein: ‘Hey, now’s the time. You want to change it up? Go ahead,’” Pollack said.

This finding suggests that the molecular transition is guided by this specific type of unwrapping. It’s a step toward better understanding of DNA access during transcription, replication and repair.

“The reason why these structures are so important, in addition to packaging, is that it also gives cells the opportunity to control which genes are on and off,” Tokuda said.

Tokuda adds that misregulation of chromatin remodeling is also implicated in many human diseases, from neuro-development and degenerative disorders to immunodeficiency syndromes and cancer.

“We hope that by developing these tools to investigate the fundamental mechanism of remodeler proteins,” he said, “we may be able to provide insight that will aid in the development of new therapeutic strategies for these diseases.”

This work was supported by grants from the National Institutes of Health.

See the full article here .

Please help promote STEM in your local schools.

Stem Education Coalition
Once called “the first American university” by educational historian Frederick Rudolph, Cornell University represents a distinctive mix of eminent scholarship and democratic ideals. Adding practical subjects to the classics and admitting qualified students regardless of nationality, race, social circumstance, gender, or religion was quite a departure when Cornell was founded in 1865.

Today’s Cornell reflects this heritage of egalitarian excellence. It is home to the nation’s first colleges devoted to hotel administration, industrial and labor relations, and veterinary medicine. Both a private university and the land-grant institution of New York State, Cornell University is the most educationally diverse member of the Ivy League.

On the Ithaca campus alone nearly 20,000 students representing every state and 120 countries choose from among 4,000 courses in 11 undergraduate, graduate, and professional schools. Many undergraduates participate in a wide range of interdisciplinary programs, play meaningful roles in original research, and study in Cornell programs in Washington, New York City, and the world over.

From Cornell: Women in STEM – “In Search of New Physics Phenomena” Julia Thom-Levy

Cornell University

1.13.17
Alexandra Chang

Julia Thom-Levy
Associate Professor
Physics, College of Arts and Sciences
Expertise
Experimental high energy physics; experimental particle physics; Large Hadron Collider, solid state detectors for particle physics

More than 3,800 miles away and across the Atlantic Ocean from Cornell’s Physical Sciences Building is Geneva, Switzerland, the home of the European Organization for Nuclear Research (CERN) laboratory and the highest-energy particle accelerator on earth.

LHC at CERN

Cornell at CERN

Despite the distance, Cornell researchers are actively involved in the cutting-edge particle physics experiments taking place at CERN. Julia Thom-Levy, Physics, is one such professor. Thom-Levy has worked on the Compact Muon Solenoid (CMS) experiment at CERN’s Large Hadron Collider (LHC) since 2005.

CERN/CMS Detector

Specifically, Thom-Levy is on a collaborative team of Cornell researchers who are responsible for developing software for the CMS detector, designing upgrades to the detector, and analyzing data collected by the CMS—all in search of new physics phenomena.

CMS is one of the two LHC detectors that led to the discovery of the Higgs boson (an elementary particle in the Standard Model of particle physics) in 2012 during the most recent LHC run. Since then, the LHC has been undergoing repairs. A second run took place during June 2015, with the LHC running at twice the energy, a major improvement that could lead to further discoveries.

“We are in an interesting situation here: a mathematical model—The Standard Model—explains all particle observations very well,” says Thom-Levy, who played a role in confirming the Standard Model to better precision over the past 15 years.

The Standard Model of elementary particles (more schematic depiction), with the three generations of matter, gauge bosons in the fourth column, and the Higgs boson in the fifth.

“It’s a very precise model. We know, however, that it doesn’t hold water, because we cannot explain certain important things like dark matter, or how exactly the Higgs boson ends up with the mass that we measure. There is a strange tension: on the one hand, we know what these particles do; we can predict it, but we don’t know why.”

Supersymmetry

Thom-Levy says that the second run of the LHC could reveal new particles, or inconsistencies in the data—“smoking guns” that will point scientists in the right direction. For example, they could find particles that might be consistent with supersymmetry, a proposed extension of the Standard Model, which could explain such mysteries as dark matter.

Dark matter in our universe has been elusive so far to detection—it does not emit or absorb light. Thom-Levy says that the LHC might, however, be able to produce dark matter, and that it is possible to observe it through its distinctive signature in the detector, which is the signature of nothing. One possibility is that dark matter consists of the lightest supersymmetric particles, and discovering it in the next run would be a huge boon to the researchers.

That said, Thom-Levy is cautious in her predictions. “I’m being very hypothetical,” she says. “The big glaring signature for supersymmetry did not appear in the first run. That was one of the surprises. It’s such a beautiful theory and we joke that it would be a shame if nature didn’t work that way. It’s something we will continue to look for.”

The Big Data Element

The Cornell CMS group—James Alexander, Richie Patterson, Anders Ryd, Peter Wittich, and Thom-Levy along with their students and postdocs—play a critical role in developing software to record and interpret the incredible amounts of data collected by the CMS.

Members of the Thom-Levy research group

When the detector is running, it records terabytes of data every day, and that data needs to be stored and distributed to various research institutions across the world for analysis. Researchers write programs to filter through trillions of proton interactions to get to the ones that are really interesting—ones that produce a Higgs or a top quark, for example.

“The most interesting interactions are often the most rare; they are the highest energy, highest masses, and very unlikely to be produced,” says Thom-Levy. “A lot of our field is like needle-in-the-haystack research.” Because of this, Thom-Levy says her students are exposed to “big-data,” and they learn how to handle and analyze huge volumes of data.

Students also spend time at CERN and learn how to make the detector work. Many of the group’s students are currently in Geneva, writing software for and testing electronics on the CMS detector.

Next-Generation Detectors

Thom-Levy is also developing better detectors, using the latest cutting-edge materials and technologies. One challenge is that the particle’s high energies result in extremely high radiation levels, which damage the detector. As energy levels and particle density increase, the detectors need to become better at withstanding radiation, while still providing high precision measurements.

To address that and other problems, Thom-Levy is involved in a collaborative project testing the use of three-dimensional integrated circuitry for silicon detectors. She says that it could make detectors much thinner, use less power, and make them potentially stronger against radiation. So far, her group has simulated detectors and prototyped components at the Cornell NanoScale Science and Technology Facility (CNF). The next steps would be to work with more industry and university partners to hopefully build the next generation of detectors to be used at CERN’s CMS.

Pursuing the Universe’s Mysteries

Thom-Levy describes her journey to CERN as a sort of odyssey following the most interesting particle physics to various places. She started at Germany’s national accelerator lab, moved on to Stanford’s Linear Accelerator Center, off to Fermilab in Illinois, until finally landing at CERN. “With each move, the energy went up,” she says with a laugh.

When asked why she was drawn to particle physics in the first place, she gives credit to the local accelerator in her hometown. “I always knew I wanted to do sub-nuclear physics,” she says. “How does the nucleus work? What does it consist of? Can you break its constituents down, down, down? What’s the most fundamental unit in the universe?”

These are questions that are both scientific and philosophical to Thom-Levy. “We want to get to the very essence. It’s nothing we can touch, but the shadows of the mysterious workings of tiny particles may tell us about the most fundamental truth of the world.”

See the full article here .

Please help promote STEM in your local schools.

Stem Education Coalition
Once called “the first American university” by educational historian Frederick Rudolph, Cornell University represents a distinctive mix of eminent scholarship and democratic ideals. Adding practical subjects to the classics and admitting qualified students regardless of nationality, race, social circumstance, gender, or religion was quite a departure when Cornell was founded in 1865.

Today’s Cornell reflects this heritage of egalitarian excellence. It is home to the nation’s first colleges devoted to hotel administration, industrial and labor relations, and veterinary medicine. Both a private university and the land-grant institution of New York State, Cornell University is the most educationally diverse member of the Ivy League.

On the Ithaca campus alone nearly 20,000 students representing every state and 120 countries choose from among 4,000 courses in 11 undergraduate, graduate, and professional schools. Many undergraduates participate in a wide range of interdisciplinary programs, play meaningful roles in original research, and study in Cornell programs in Washington, New York City, and the world over.

From Cornell: “With CLEO detector gone, CHESS facility looks back, ahead”

Cornell University

Dec. 13, 2016
Tom Fleischman
tjf85@cornell.edu

The 26-ton solenoidal superconducting magnet is carefully taken out of its chamber inside the CLEO detector during removal of the detector earlier this year at Wilson Synchrotron Laboratory. Rick Ryan, CLASSE/Provided

Three months ago, without a whole lot of fanfare, an era in particle physics at Cornell came to an end.

On Sept. 6, the 26-ton solenoidal superconducting magnet was carefully removed from the Wilson Synchrotron Laboratory. This was the last vestige of the CLEO detector, which for nearly 30 years recorded data produced from the collision of positively and negatively charged electrons that hurtled around the 840-yard subterranean collider, CESR (Cornell Electron-positron Storage Ring).

Cornell Electron-positron Storage Ring

The magnet has been sent to the Thomas Jefferson National Accelerator Facility in Newport News, Virginia, where in several years it will begin providing a magnetic field for a new experiment there. CLEO’s removal heralds a new direction for the Cornell High-Energy Synchrotron Source (CHESS), which soon will undergo a $15 million upgrade to enhance the quality of its X-ray beams.

http://www.chess.cornell.edu/

With the removal of CLEO, the path is clear for the CHESS upgrade, after which the accelerator will operate with a single beam of positrons optimized for X-ray production instead of counter-rotating electron and positron beams. This will enable all CHESS beam lines to be aligned to a single beam orbit, enhancing the X-ray beam quality for research in physics, chemistry, biology, and environmental and materials sciences.

CLEO underwent numerous upgrades and produced a mountain of data from its completion in 1979 to its final run on March 3, 2008. The first CLEO paper listed 73 authors from eight institutions; the most authors on a paper produced there was 226.

“That was an incredibly productive time,” said James Alexander, physics professor and former director of the Laboratory of Elementary-Particle Physics. “We published more than 500 papers – in fact, in the few years after 2008, there were still papers coming out.” The total reached 530 peer-reviewed publications.

The calorimeter, used to measure the heat produced in a chemical reaction, is taken out of the CLEO detector during removal of the detector earlier this year at Wilson Lab. Rick Ryan, CLASSE/Provided

“In those days, we were way ahead of everybody,” said Alexander, who’s been at Cornell since 1988. “We published more papers than any other high-energy physics experiment. … everybody wanted to hear what CLEO’s latest results were.”

CLEO carried out a broad physics program of studying the production and decay of various matter particles (bottom and charm quarks, as well as tau leptons) and searching for new phenomena beyond the Standard Model of particle physics. It was cutting-edge stuff at Wilson Lab, a facility that had gotten used to breaking new ground over the course of a half-century.

Cornell’s involvement in nuclear physics began in 1934, when members of the physics faculty convinced M. Stanley Livingston to leave the world’s first cyclotron, which he helped build at Stanford University, to come to Ithaca and build the second.

The CLEO era began in 1979 and over the years included 42 institutions and more than 400 physicists from around the world. CLEO’s heyday was in the 1990s, due in large part to CESR’s status as the highest-luminosity collider in the world following a couple of major upgrades in the 1980s.

Also contributing was U.S. Congress’ decision to defund a large accelerator program in Texas [Superconducting Super Collider. Our brilliant Congress ceded HEP to CERN in Europe, which Steven Weinberg (U Texas) has never gotten completely over].

Superconducting Super Sollider map, in the vicinity of Waxahachie, Texas

“When that was killed off, there were a lot of high-energy physics groups across the country that had the rug pulled out from under them, and many of them joined CLEO,” Alexander said.

CLEO underwent five upgrades over the years, but by 2003, with new detectors springing up at Stanford and in Japan to do the same work as CLEO, “we saw the writing on the wall,” he said.

“We all sat back here thinking, ‘They don’t know how hard it is; it’ll take them far longer than they think; we’re going to remain king of the hill for a long time to come,’” he said. “It didn’t happen – when they both turned on, it was like a rocket.”

CLEO shifted its focus to lower-energy study of a different variety of quark, but in 2008 funding dried up, and CLEO – as well the Stanford program, called BaBar – shut off for good.

The process of removing the CLEO detector started in the spring, and was a difficult and delicate operation involving contributors from several departments.

“It’s been very nostalgic to see CLEO removed,” said senior physicist Brian Heltsley, who’s been at Cornell for more than 30 years. “And it’s been really impressive, with all the rigging needed to get these 30-ton hunks of metal out of the lab. I think it was an opportunity for our staff to shine; a place like this doesn’t run without electronics experts, riggers, all sorts of technicians at every level, and administrators.”

Heltsley said that intellectual standards over the years have been “unyieldingly high” at Wilson Lab.

“Over those years, habits become ingrained,” he said. “And that high standard of performance, of testing, of leaving nothing to chance … that permeates not only the academics but filters down all the way to every aspect of the lab. Supervisors, technicians, everyone: They will not accept a mediocre job.”

The pending upgrade will, among other things, configure CESR for single-beam X-ray operations and optimize the experiment stations for specific measurements. “This new project,” Heltsley said, “will continue that high standard of intellectual and technical sophistication.”

CHESS annually hosts more than 1,200 scientists and scientists-in-training. It is supported by the Division of Materials Research and the Directorates of Biology and Engineering of the National Science Foundation.

See the full article here .

Please help promote STEM in your local schools.

Stem Education Coalition
Once called “the first American university” by educational historian Frederick Rudolph, Cornell University represents a distinctive mix of eminent scholarship and democratic ideals. Adding practical subjects to the classics and admitting qualified students regardless of nationality, race, social circumstance, gender, or religion was quite a departure when Cornell was founded in 1865.

Today’s Cornell reflects this heritage of egalitarian excellence. It is home to the nation’s first colleges devoted to hotel administration, industrial and labor relations, and veterinary medicine. Both a private university and the land-grant institution of New York State, Cornell University is the most educationally diverse member of the Ivy League.

On the Ithaca campus alone nearly 20,000 students representing every state and 120 countries choose from among 4,000 courses in 11 undergraduate, graduate, and professional schools. Many undergraduates participate in a wide range of interdisciplinary programs, play meaningful roles in original research, and study in Cornell programs in Washington, New York City, and the world over.