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  • richardmitnick 11:13 am on June 22, 2020 Permalink | Reply
    Tags: "Comb on a Chip: New Design for ‘Optical Ruler’ Could Revolutionize Clocks; Telescopes; Telecommunications", , , Optical microresonator, UCSB- University of California Santa Barbara   

    From NIST and UCSB: “Comb on a Chip: New Design for ‘Optical Ruler’ Could Revolutionize Clocks, Telescopes, Telecommunications” 

    UC Santa Barbara Name bloc
    UC Santa Barbara


    From NIST

    June 22, 2020
    Media Contact

    Ben P. Stein
    benjamin.stein@nist.gov

    (301) 975-2763

    Technical Contact

    Gregory Moille
    gregory.moille@nist.gov

    (301) 975-8413

    1
    Credit: NIST

    Just as a meter stick with hundreds of tick marks can be used to measure distances with great precision, a device known as a laser frequency comb, with its hundreds of evenly spaced, sharply defined frequencies, can be used to measure the colors of light waves with great precision.

    Small enough to fit on a chip, miniature versions of these combs — so named because their set of uniformly spaced frequencies resembles the teeth of a comb — are making possible a new generation of atomic clocks, a great increase in the number of signals traveling through optical fibers, and the ability to discern tiny frequency shifts in starlight that hint at the presence of unseen planets. The newest version of these chip-based “microcombs,” created by researchers at the National Institute of Standards and Technology (NIST) and the University of California at Santa Barbara (UCSB), is poised to further advance time and frequency measurements by improving and extending the capabilities of these tiny devices.

    At the heart of these frequency microcombs lies an optical microresonator, a ring-shaped device about the width of a human hair in which light from an external laser races around thousands of times until it builds up high intensity. Microcombs, often made of glass or silicon nitride, typically require an amplifier for the external laser light, which can make the comb complex, cumbersome and costly to produce.

    The NIST scientists and their UCSB collaborators have demonstrated that microcombs created from the semiconductor aluminum gallium arsenide have two essential properties that make them especially promising. The new combs operate at such low power that they do not need an amplifier, and they can be manipulated to produce an extraordinarily steady set of frequencies — exactly what is needed to use the microchip comb as a sensitive tool for measuring frequencies with extraordinary precision. (The research is part of the NIST on a Chip program.)

    The newly developed microcomb technology can help enable engineers and scientists to make precision optical frequency measurements outside the laboratory, said NIST scientist Gregory Moille. In addition, the microcomb can be mass-produced through nanofabrication techniques similar to the ones already used to manufacture microelectronics.

    The researchers at UCSB led earlier efforts in examining microresonators composed of aluminum gallium arsenide. The frequency combs made from these microresonators require only one-hundredth the power of devices fabricated from other materials. However, the scientists had been unable to demonstrate a key property — that a discrete set of unwavering, or highly stable, frequencies could be generated from a microresonator made of this semiconductor.

    The NIST team tackled the problem by placing the microresonator within a customized cryogenic apparatus that allowed the researchers to probe the device at temperatures as low as 4 degrees above absolute zero. The low-temperature experiment revealed that the interaction between the heat generated by the laser light and the light circulating in the microresonator was the one and only obstacle preventing the device from generating the highly stable frequencies needed for successful operation.

    At low temperatures, the team demonstrated that it could reach the so-called soliton regime — where individual pulses of light that never change their shape, frequency or speed circulate within the microresonator. The researchers describe their work in the June issue of Laser and Photonics Reviews.

    With such solitons, all teeth of the frequency comb are in phase with each other, so that they can be used as a ruler to measure the frequencies employed in optical clocks, frequency synthesis, or laser-based distance measurements.

    Although some recently developed cryogenic systems are small enough that they could be used with the new microcomb outside the laboratory, the ultimate goal is to operate the device at room temperature. The new findings show that scientists will either have to quench or entirely avoid excess heating to achieve room-temperature operation.

    See the full article here.

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    NIST Campus, Gaitherberg, MD, USA

    NIST Mission, Vision, Core Competencies, and Core Values

    NIST’s mission

    To promote U.S. innovation and industrial competitiveness by advancing measurement science, standards, and technology in ways that enhance economic security and improve our quality of life.
    NIST’s vision

    NIST will be the world’s leader in creating critical measurement solutions and promoting equitable standards. Our efforts stimulate innovation, foster industrial competitiveness, and improve the quality of life.
    NIST’s core competencies

    Measurement science
    Rigorous traceability
    Development and use of standards

    NIST’s core values

    NIST is an organization with strong values, reflected both in our history and our current work. NIST leadership and staff will uphold these values to ensure a high performing environment that is safe and respectful of all.

    Perseverance: We take the long view, planning the future with scientific knowledge and imagination to ensure continued impact and relevance for our stakeholders.
    Integrity: We are ethical, honest, independent, and provide an objective perspective.
    Inclusivity: We work collaboratively to harness the diversity of people and ideas, both inside and outside of NIST, to attain the best solutions to multidisciplinary challenges.
    Excellence: We apply rigor and critical thinking to achieve world-class results and continuous improvement in everything we do.

     
  • richardmitnick 9:52 am on February 29, 2020 Permalink | Reply
    Tags: , , , Betelgeuse is dying., Betelgeuse' supernova could produce a dazzling display that could be visible even in daylight., , , The red supergiant is nearing the end of its life and when a star over 10 times the mass of the Sun dies it goes out in spectacular fashion., UCSB- University of California Santa Barbara   

    From UC Santa Barbara: “A Massive Star’s Dying Breaths” 

    UC Santa Barbara Name bloc
    From UC Santa Barbara

    February 28, 2020
    Harrison Tasoff
    (805) 893-7220
    harrisontasoff@ucsb.edu

    1
    Supernovae are stupendously energetic; many can briefly outshine an entire galaxy. Artist’s impression.
    Photo Credit: ESO/M. Kornmesser.

    Betelgeuse has been the center of significant media attention lately. The red supergiant is nearing the end of its life, and when a star over 10 times the mass of the Sun dies, it goes out in spectacular fashion. With its brightness recently dipping to the lowest point in the last hundred years, many space enthusiasts are excited that Betelgeuse may soon go supernova, exploding in a dazzling display that could be visible even in daylight.

    While the famous star in Orion’s shoulder will likely meet its demise within the next million years — practically couple days in cosmic time — scientists maintain that its dimming is due to the star pulsating. The phenomenon is relatively common among red supergiants, and Betelgeuse has been known for decades to be in this group.

    Coincidentally, researchers at UC Santa Barbara have already made predictions about the brightness of the supernova that would result when a pulsating star like Betelgeuse explodes.

    Physics graduate student Jared Goldberg has published a study with Lars Bildsten, director of the campus’s Kavli Institute for Theoretical Physics (KITP) and Gluck Professor of Physics, and KITP Senior Fellow Bill Paxton detailing how a star’s pulsation will affect the ensuing explosion when it does reach the end. The paper appears in The Astrophysical Journal.

    “We wanted to know what it looks like if a pulsating star explodes at different phases of pulsation,” said Goldberg, a National Science Foundation graduate research fellow. “Earlier models are simpler because they don’t include the time-dependent effects of pulsations.”

    When a star the size of Betelgeuse finally runs out of material to fuse in its center, it loses the outward pressure that kept it from collapsing under its own immense weight. The resultant core collapse happens in half a second, far faster than it takes the star’s surface and puffy outer layers to notice.

    As the iron core collapses the atoms disassociate into electrons and protons. These combine to form neutrons, and in the process release high-energy particles called neutrinos. Normally, neutrinos barely interact with other matter — 100 trillion of them pass through your body every second without a single collision. That said, supernovae are among the most powerful phenomena in the universe. The numbers and energies of the neutrinos produced in the core collapse are so immense that even though only a tiny fraction collides with the stellar material, it’s generally more than enough to launch a shockwave capable of exploding the star.

    That resulting explosion smacks into the star’s outer layers with stupefying energy, creating a burst that can briefly outshine an entire galaxy. The explosion remains bright for around 100 days, since the radiation can escape only once ionized hydrogen recombines with lost electrons to become neutral again. This proceeds from the outside in, meaning that astronomers see deeper into the supernova as time goes on until finally the light from the center can escape. At that point, all that’s left is the dim glow of radioactive fallout, which can continue to shine for years.

    A supernova’s characteristics vary with the star’s mass, total explosion energy and, importantly, its radius. This means Betelgeuse’s pulsation makes predicting how it will explode rather more complicated.

    The researchers found that if the entire star is pulsating in unison — breathing in and out, if you will — the supernova will behave as though Betelgeuse was a static star with a given radius. However, different layers of the star can oscillate opposite each other: the outer layers expand while the middle layers contract, and vice versa.

    For the simple pulsation case, the team’s model yielded similar results to the models that didn’t account for pulsation. “It just looks like a supernova from a bigger star or a smaller star at different points in the pulsation,” Goldberg explained. “It’s when you start considering pulsations that are more complicated, where there’s stuff moving in at the same time as stuff moving out — then our model actually does produce noticeable differences,” he said.

    In these cases, the researchers discovered that as light leaks out from progressively deeper layers of the explosion, the emissions would appear as though they were the result of supernovae from different sized stars.

    “Light from the part of the star that is compressed is fainter,” Goldberg explained, “just as we would expect from a more compact, non-pulsating star.” Meanwhile, light from parts of the star that were expanding at the time would appear brighter, as though it came from a larger, non-pulsating star.

    Goldberg plans to submit a report to Research Notes of the American Astronomical Society with Andy Howell, a professor of physics, and KITP postdoctoral researcher Evan Bauer summarizing the results of simulations they ran specifically on Betelgeuse. Goldberg is also working with KITP postdoc Benny Tsang to compare different radiative transfer techniques for supernovae, and with physics graduate student Daichi Hiramatsu on comparing theoretical explosion models to supernova observations.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education CoalitionUC Santa Barbara Seal
    The University of California, Santa Barbara (commonly referred to as UC Santa Barbara or UCSB) is a public research university and one of the 10 general campuses of the University of California system. Founded in 1891 as an independent teachers’ college, UCSB joined the University of California system in 1944 and is the third-oldest general-education campus in the system. The university is a comprehensive doctoral university and is organized into five colleges offering 87 undergraduate degrees and 55 graduate degrees. In 2012, UCSB was ranked 41st among “National Universities” and 10th among public universities by U.S. News & World Report. UCSB houses twelve national research centers, including the renowned Kavli Institute for Theoretical Physics.

     
  • richardmitnick 2:30 pm on February 18, 2020 Permalink | Reply
    Tags: "Predators to Spare", California sheepheads-urchin predators, California spiny lobsters prey on sea urchins, Diversity and redundancy-very important., Sea urchins, The sunflower star was a particularly important predator of sea urchins-but they have disappeared., UCSB- University of California Santa Barbara, Without predators to keep them in check urchin populations can explode and begin eating their way through kelp forests turning them into urchin barrens.   

    From UC Santa Barbara: “Predators to Spare” 

    UC Santa Barbara Name bloc
    From UC Santa Barbara

    February 12, 2020
    Harrison Tasoff
    (805) 893-7220
    harrisontasoff@ucsb.edu

    1
    Without predators to keep them in check, urchin populations can explode and begin eating their way through kelp forests, turning them into urchin barrens.

    In 2014, a disease of epidemic proportions gripped the West Coast of the U.S. You may not have noticed, though, unless you were underwater.

    Fueled by abnormally hot ocean temperatures, sea star wasting disease ravaged these echinoderms from Alaska to Mexico. The condition, still not fully understood, wiped out a significant marine predator, the sunflower star. The sunflower star was a particularly important predator of sea urchins, and since the sea star’s disappearance, the urchins it preyed upon have multiplied and laid waste to large swaths of kelp forest. However, the spiny scourge seemed to have spared some areas, especially those where multiple urchin predators occurred, particularly within marine protected areas.

    A team of marine biologists, led by recent UC Santa Barbara graduate Jake Eisaguirre, has investigated what factors kept urchins in check in marine protected areas in the western Channel Islands. They found that a redundancy in urchin predators, and the protection afforded to them, seems to be responsible. The results offer a new perspective on strategies to manage ecosystems for resilience and highlight an underappreciated benefit of marine reserves. The study appears in the journal Ecology.

    “This sea star wasting disease was a very impactful and rapid event,” said Jennifer Caselle, a research biologist at the university’s Marine Science Institute (MSI), an adjunct faculty member in ecology, evolution and marine biology and one of the study’s coauthors. “We had abundant sea stars on our reefs, and within one year we had no sea stars.” The researchers haven’t seen a single sunflower star since 2014.

    The sunflower star’s disappearance rippled through the entire kelp forest food web in what scientists call a trophic cascade. The team’s research indicated that even a few sunflower stars could effectively control an area’s urchin population, so without them, the populations exploded, and the kelp forests turned into barrens in many places in California.

    And unfortunately, it’s easier for a kelp forest to become an urchin barren than for it to return to its original state. “There are feedbacks that prevent it from shifting back,” said lead author Eisaguirre. “One of them could be that the abundant urchins on the ‘urchin barrens’ are starved and provide no nutrition to predators, so nothing wants to eat them.”

    Puzzling oases

    While the urchins mowed down vast tracts of kelp in some regions, especially in Northern California, the researchers noticed that kelp in marine protected areas off the Channel Islands was still relatively healthy. They suspected it may be related to the urchin’s other two predators in the region: the California sheephead and California spiny lobster.

    2
    A male California sheephead looms among the kelp fronds. Photo Credit: KATIE DAVIS.

    Both of these species occur primarily in Southern California, and are both heavily fished. “We thought that the protection of these other predators, even though they weren’t highly abundant in the western part of the Channel, may still have helped to compensate for the loss of the sunflower star,” said coauthor Katie Davis, a research scientist at MSI.

    The patchwork layout of marine protected areas around the Channel Islands provided an ideal setup to test the effect marine reserves had on sea urchin predators, and accordingly, the urchins themselves. Adjacent areas are virtually identical except for their status as open or closed to fishing. What’s more, the research group has been collecting data in the area for more than 20 years under the Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO), a long-term ecological project.

    The team looked at data spanning several years before and after the onset of sea star wasting disease, examining how the assemblage of urchin predators changed. They used statistical models to investigate how different variables — like the size and abundance of the three predators, protected status of different sites and sea surface temperature — might have affected sea urchin populations. These models suggested that not only the abundance, but also the size of the remaining predators in the system were important.

    Diversity and redundancy

    Before the onset of the disease, the abundance of sunflower stars had the most pronounced effect on urchin populations. However, after the outbreak, the best predictors of urchin numbers were the abundance and size of the remaining predators. And, by comparing across a number of sites, the researchers found that predators were more abundant and larger within protected areas.

    The scientists concluded that the marine protected areas released the predators from fishing pressures, so they were able to effectively fill the void left after the sunflower stars died off. Outside the protected areas, where the predators are smaller and less abundant, they were less able to compensate for the loss of the sea stars. This is one of the first studies showing that marine protected areas can confer ecosystem resilience by ensuring the protection of critical species functions.

    “When you have multiple different species all performing similar functions, if something catastrophic happens to one of them, those functions can still be maintained,” explained Caselle. In this case the function was predation, but the concept applies more broadly.

    3
    California spiny lobster spend most of their days in rocky crevasses, venturing out at night to hunt. Photo Credit: KATIE DAVIS.

    The state of affairs in Northern California supported the team’s conclusion. The ocean north of San Francisco is too cold for sheephead and lobsters, and the otters that are well established on the Central Coast haven’t been able to get a foothold north of the bay. As a result, the urchin population grew relatively unchecked once the sunflower star disappeared. The spiny hordes have since decimated the kelp forests of Northern California and the Pacific Northwest.

    The scientists also found that predators’ sizes made a big difference, especially for the sheephead. “What surprised us the most was that even really small differences in sheephead size resulted in really big differences in how many urchins they could eat,” Caselle said. This is because bigger fish have bigger mouths that can crack bigger sea urchins.

    One of the most common effects in marine reserves is that fish grow larger and become more numerous. Many studies have shown that this increases reproduction rates, since larger fish release disproportionately more eggs than smaller fish. However, this study is one of the first to highlight another, underappreciated effect: The larger fish are also able to better control urchins, eating more of them, as well as the larger, more fertile individuals.

    “And that’s important because even small differences in fishing pressure can result in those size class differences for the sheephead,” Caselle added.

    “We are moving into a situation now where resource managers and resource users are having serious conversations about active restoration of kelp forests and other habitats being altered by climate change. Restoration may be the only option if we want kelp forests to retain their functions and their diversity,” she continued. Fortunately, these findings show that we may be able to manage ecosystems for resilience to environmental changes by protecting multiple species that provide critical functions and recognizing that redundancy is important.

    In the future, the team wants to investigate the feedback cycles at work, especially those involving sheephead, with an eye toward how these insights can be leveraged for ecosystem restoration. They will also continue their long-term monitoring with a special focus on understanding the effectiveness of marine protected areas and how they confer resilience to climate change.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education CoalitionUC Santa Barbara Seal
    The University of California, Santa Barbara (commonly referred to as UC Santa Barbara or UCSB) is a public research university and one of the 10 general campuses of the University of California system. Founded in 1891 as an independent teachers’ college, UCSB joined the University of California system in 1944 and is the third-oldest general-education campus in the system. The university is a comprehensive doctoral university and is organized into five colleges offering 87 undergraduate degrees and 55 graduate degrees. In 2012, UCSB was ranked 41st among “National Universities” and 10th among public universities by U.S. News & World Report. UCSB houses twelve national research centers, including the renowned Kavli Institute for Theoretical Physics.

     
  • richardmitnick 3:37 pm on October 1, 2019 Permalink | Reply
    Tags: , Data Silos- the current state of infomation, , , Space and time matter-knowing where and when things happen is critical to understanding why and how they happened or will happen., The job of the researchers is to develop artificial intelligence methods of organizing huge sets of information into formats that can be read and understood across disciplines ., The project: “Spatially Explicit Models Methods and Services for Open Knowledge Networks”, UCSB- University of California Santa Barbara   

    From UC Santa Barbara: “Breaking Data out of the Silos” 

    UC Santa Barbara Name bloc

    October 1, 2019
    Sonia Fernandez
    (805) 893-4765
    sonia.fernandez@ucsb.edu

    Researchers receive NSF grant to develop spatially explicit open knowledge networks.

    1

    Our world is teeming with data, all of it just waiting to be placed into the appropriate context. Connecting these enormous bodies of information could, according to UC Santa Barbara geographic information scientist Krzyzstof Janowicz, yield a richer, deeper understanding of the world around us.

    2
    Krzyzstof Janowicz

    “In the previous decades, data has typically been stored in what we call ‘data silos,’ ” Janowicz said. “Data gathered by one entity,” he continued, “is often ‘locked away’ and used for specific purposes, for specific ways of thinking. But what if there was a way to store, connect and provide diverse sets of data that could be useful to the many users who need it and could find creative new ways to use or combine it?”

    There is such a way, Janowicz has asserted, and with $1 million in initial funding from the National Science Foundation, he and about 20 colleagues from universities, companies and government agencies across the United States are poised to break data out of their silos. Titled “Spatially Explicit Models, Methods and Services for Open Knowledge Networks,” the project aims to create the connections between vast data sets that can lead to better understanding and more creative solutions to complex emerging problems.

    “Even for departments within a single entity, exchanging data has been difficult because one way to talk about things in one data silo is not the same as in another one,” Janowicz said.

    Enter the knowledge graph: a combination of technologies, specifications and data cultures for densely interconnecting web-scale data across domains in a human and machine readable and reason-able way. For this project, the main ordering principles to be applied to the interconnected data will be space and time.

    Space and time matter not only for the obvious reason that everything happens somewhere and at some time, but because knowing where and when things happen is critical to understanding why and how they happened or will happen. How, for instance, can climate affect politics in areas that rely heavily on agriculture? Is there a link between today’s soil health and historic slave trade? Questions like these often take considerable amounts of time and effort to answer, often with work that duplicates previous studies.

    “Instead, you can connect your local knowledge repository to global repositories to get a holistic view of your domain or your problem,” Janowicz explained, thanks to the increases in computational power and data storage.

    It’s a huge endeavor. Data can come in many forms, ranging from numerical measurements to images to verbal descriptions. The job of the researchers — who hail from UCSB’s Center for Spatial Studies, Earth Research Institute and National Center for Ecological Analysis and Synthesis, as well as Arizona State University, Michigan State University, Kansas State University, U.S. Geological Survey and industry partners such as ESRI, Oliver Wyman, and Princeton Climate Analytics — is to develop artificial intelligence methods of organizing these huge sets of information into formats and relationships that can be read and understood across disciplines, using space and time as ordering principles.

    “We would like to develop a knowledge graph together with the partners from other universities, major industry players and government organizations that contains spatial data, and we also want to make methods available for many other knowledge graphs that either use spatial data or want to enrich their data-using spatial data,” Janowicz said. He explained that much of this can be done with machine learning models that digest the enormous amounts and various types of data being generated, which can then be organized in graphs that show both the breadth and depth of knowledge of a given topic.

    He further explained that the product would be dense, widely accessible knowledge graphs that can not only reach back into history for context, but also widen our present options and risks and allow us to make informed predictions about things to come. For instance, given the data we already have about local climate, soil health and erosion, what are the chances of having another disastrous debris flow of the type that happened in Montecito, Calif., in 2018, and how should that affect local land-use planning and real estate?

    “Currently, there is no way you can query for erosion risks by linking them to extreme event databases,” Janowicz said. “But this should be the most easy thing to do on the planet. These are exactly the kinds of problems that we are tackling.”

    The initial grant is for a total of $1 million over nine months, and is part of NSF’s new Convergence Accelerator, which enables research teams to build tools that harness the data revolution and allow people from various sectors — government, academia, industry, nonprofits — to access and use data in an Open Knowledge Network.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    UC Santa Barbara Seal
    The University of California, Santa Barbara (commonly referred to as UC Santa Barbara or UCSB) is a public research university and one of the 10 general campuses of the University of California system. Founded in 1891 as an independent teachers’ college, UCSB joined the University of California system in 1944 and is the third-oldest general-education campus in the system. The university is a comprehensive doctoral university and is organized into five colleges offering 87 undergraduate degrees and 55 graduate degrees. In 2012, UCSB was ranked 41st among “National Universities” and 10th among public universities by U.S. News & World Report. UCSB houses twelve national research centers, including the renowned Kavli Institute for Theoretical Physics.

     
  • richardmitnick 3:29 pm on September 3, 2019 Permalink | Reply
    Tags: "Undercover Evolution", A group of researchers at UC Santa Barbara have discovered that embryos that appear the same can start out with surprisingly different instructions., Enter the C. elegans nematode worm- a celebrated laboratory animal model used for decades to investigate how animals develop., Key parts of the assembly instructions used when embryos first start developing can differ dramatically between individuals of the same species., The discovery of such hidden genetic mechanisms could help guide how pharmaceuticals are developed in this era of precision medicine., The genetic assembly instructions that get us started at conception were thought to be nearly identical between us., The team which included researchers at the University of Auckland targeted the gene switches that turn on the development of the animal’s intestine with a tool called RNAi., These findings also shine light on why patients can respond so differently to drug therapies., This finding may shed light on two important areas: how animals can evolve quickly; and why patients can show very different responses to particular drugs., This technique that shuts down individual gene functions., UCSB- University of California Santa Barbara, What they learned was that the widely accepted “standard one-size-fits-all” concept of genetic assembly instructions did not apply.   

    From UC Santa Barbara: “Undercover Evolution” 

    UC Santa Barbara Name bloc
    From UC Santa Barbara

    September 3, 2019
    Sonia Fernandez
    (805) 893-4765
    sonia.fernandez@ucsb.edu

    1

    Large variation in the genetic switches for key events in the early embryo in a single species is consistent with the “hourglass” view of embryo evolution. Photo Credit: Joel Rothman

    2
    C. elegans worms showing pharynx (red) and intestine (“endoderm” in green and cyan) portions of the digestive tract.
    Photo Credit: Pradeep Joshi

    Providing a glimpse of the hidden workings of evolution, a group of researchers at UC Santa Barbara have discovered that embryos that appear the same can start out with surprisingly different instructions.

    “We found that a lot of undercover evolution occurs in early embryos,” said Joel Rothman, a professor in the Department of Molecular, Cellular, and Developmental Biology, who led the team.

    Indeed, although members of the same species are identical across the vast majority of their genomes, including all the genetic instructions used in development, Rothman and his colleagues found that key parts of the assembly instructions used when embryos first start developing can differ dramatically between individuals of the same species.

    This finding may shed light on two important areas: how animals can evolve quickly, and why patients can show very different responses to particular drugs.

    The scientists’ research is published in the journal eLife.

    “Many of the distinctive features that make us unique, including our color, height and susceptibility to diseases, are determined by our genomes,” Rothman said. “But since everyone looks pretty similar as embryos, the genetic assembly instructions that get us started at conception were thought to be nearly identical between us.”

    Enter the C. elegans nematode worm, a celebrated laboratory animal model used for decades to investigate how animals develop. Rothman’s team, which included researchers at the University of Auckland, targeted the gene switches that turn on the development of the animal’s intestine with a tool called RNAi — a technique that shuts down individual gene functions. What they learned was that the widely accepted “standard one-size-fits-all” concept of genetic assembly instructions did not apply.

    “This remarkable difference is well-hidden in the genome, but was uncovered when one of the switches was removed,” noted Yamila Torres Cleuren, formerly of University of Auckland and now a postdoctoral fellow at the University of Bergen and lead author of the study. “We were startled to find that while some members of the species absolutely require one of the critical switches to start making an intestine, others can almost dispose of it.” While some animals generally failed to develop intestines, relatives from the same species made them regardless.

    “It’s stunning that such an important event at the earliest stages of embryo formation can occur by such different means within one species and yet produce essentially the same outcome,” said Rothman. “Prior to these findings, we were unaware that the blueprints for an early embryo change so rapidly within a species.”

    This discovery would be equivalent to finding that the manufacturing of two iPhones, which look and function identically, started out with different assembly instructions, the researchers said.

    While humans are a far cry from C. elegans, once the initial events in embryo development begin, the later genetic instructions that create the endoderm appear to be similar to those likely used in all animals with a digestive tract, including humans.

    This result is particularly striking given that the endoderm is both the first layer formed in embryos and was probably the first to evolve over half a billion years ago. “It reveals an extreme version of the first part of the ‘hourglass’ view of embryo development, in which very similar instructions across widely different animals during the middle stages of development are preceded and followed by very different starting and ending points,” Rothman said.

    These findings also shine light on why patients can respond so differently to drug therapies. “We found that these animals with relatively subtle genetic differences respond wildly differently to a genetic ‘drug’ that we used to turn off a gene,” Torres Cleuren said.

    Thus, just as two people who might look very similar can respond very differently to a drug therapy, so these little worms of the same species respond dramatically differently to an administered substance as a result of their subtle but all-important genetic individuality, the researchers said.

    The discovery of such hidden genetic mechanisms could help guide how pharmaceuticals are developed in this era of precision medicine, in which drugs are ideally tailored to an individual’s genome.

    This discovery also underscores the importance of natural variation in allowing evolution to occur. “Genetic variation fuels the machine of evolution,” Rothman said. “Without it, life would be stuck in a dead end. There is much more of this variation than we had realized when evolution sculpts the remarkable entities known as embryos.”

    Research in this study was conducted also by Chee Kiang Ewe, Kyle C. Chipman, Cricket G. Wood, Melissa R. Alcorn, Thomas L. Turner and Pradeep M. Joshi at UCSB; and Emily R. Mears, Coco Emma Alma Al-Alami and Russell G. Snell at University of Auckland.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    UC Santa Barbara Seal
    The University of California, Santa Barbara (commonly referred to as UC Santa Barbara or UCSB) is a public research university and one of the 10 general campuses of the University of California system. Founded in 1891 as an independent teachers’ college, UCSB joined the University of California system in 1944 and is the third-oldest general-education campus in the system. The university is a comprehensive doctoral university and is organized into five colleges offering 87 undergraduate degrees and 55 graduate degrees. In 2012, UCSB was ranked 41st among “National Universities” and 10th among public universities by U.S. News & World Report. UCSB houses twelve national research centers, including the renowned Kavli Institute for Theoretical Physics.

     
  • richardmitnick 10:10 am on August 11, 2019 Permalink | Reply
    Tags: , , , Mo’orea Coral Reef, , UCSB- University of California Santa Barbara   

    From UC Santa Barbara: “On the Front Lines” 

    UC Santa Barbara Name bloc
    From UC Santa Barbara

    August 7, 2019
    Sonia Fernandez
    (805) 893-4765
    sonia.fernandez@ucsb.edu

    1
    Corals at Mo’orea are experiencing bleaching. Photo Credit: Jeff Liang

    If the fight to get ahead of climate change was a battlefield, coral reefs would be on the front lines. The symbiotic relationship between alga and animal in these foundational ocean organisms has provided habitat and food for a dizzying array of species for millennia, weathering fluctuations in temperature, water chemistry, light availability and food supply.

    “This whole vibrant ecosystem hinges on the presence of these foundation species, corals, which are probably one of the most fascinating groups of animals on the planet,” said UC Santa Barbara ecologist Holly Moeller. “A tropical coral reef is this vibrant, beautiful hotspot of biodiversity, rich with colorful animal life,” which in turn, she continued, yields benefits for surrounding ecosystems, as well as human activities. Adding to the complexity: The corals are actually composites of two living organisms. The coral animal plays host to symbiotic algae which help generate the coral’s food supply by harnessing sunlight via photosynthesis.

    It’s no secret that corals are facing their biggest challenge on record, with ocean warming and acidification threatening the very relationship that makes these reefs possible. The increasing heat and changing chemistry of the water causes corals to expel their symbiotic algae, resulting in bleaching and the loss of most of the corals’ energy source, leading, in most cases, to coral death.

    As disheartening as that sounds, for Moeller it also is an invaluable opportunity to witness phenomena that are fundamental to successful life on Earth: how animals respond to changing conditions. She, along with UC Santa Barbara theoretical ecologist Roger Nisbet, and researchers from the University of Rhode Island (URI), the University of Washington (UW), Florida International University (FIU) and Shedd Aquarium in Chicago, are set to investigate how corals are responding via epigenetics to the onslaught of changes to their environments. Their work is funded by a $3 million, five-year collaborative research grant from the National Science Foundation.

    “Corals are the canary in the coal mine when it comes to climate change, and are valued in the order of hundreds of billions of dollars annually,” said Hollie Putnam, coral biologist at URI and lead investigator in the collaboration. “Better understanding their evolutionary processes and how they may acclimate through epigenetics may allow us to reduce the negative effects of events like mass bleaching and the impact the rapid loss of coral reefs has on our food security, coastal security and how the oceans impact our coasts.”

    And ground zero for this investigation? The coral reefs around Mo’orea, in French Polynesia, which is home to the National Science Foundation’s Mo’orea Coral Reef (MCR) Long-Term Ecological Research (LTER) project.

    2
    Mo’orea Coral Reef

    Under the direction of UC Santa Barbara marine scientist Russ Schmidt and Sally Holbrook, the MCR LTER has yielded years of ecological data on the structure and function of Mo’orea’s coral reefs at a time when coral reefs around the world are facing numerous threats.

    “This will provide us amazing insights into the function of Mo’orea’s coral reefs at a critical time,” said Moeller, who specializes in symbiosis and modeling. Focusing on the corals’ epigenetics — heritable changes in an organism’s observable characteristics, in direct response to their environment, that do not alter their DNA codes — is particularly interesting, she said, because corals face changing conditions throughout their life cycles, employing strategies to rapidly evolve and adapt.

    “Not only does a particular coral individual experience varied environments in its long lifespan, but when it produces babies, these babies get dispersed all over the reef and maybe to other reefs far away where conditions could be really different,” Moeller said. “How do organisms deal with this (at least partially) unpredictable environmental variation? And, how do they deal with this while still managing to make a living that includes wrangling a symbiotic alga that may or may not want to cooperate? We think epigenetic modifiers are one way to do this.”

    Using the data gathered at Mo’orea, the collaboration, which includes FIU molecular biologist and environmental genetics expert Jose Eirin-Lopez, UW conservation physiologist Steven Roberts and Shedd Aquarium research biologist Ross Cunning, intends to build predictive models for coral reef ecology and evolution that connect energy metabolism at the cellular scale to epigenetic, physiological and ecological factors. They’ll do so by using Dynamic Energy Budget models pioneered by Nisbet, who noted that “confidence in predictions from these models requires rigorous tests using data from laboratory studies and from organisms in the natural environment. This project offers unparalleled opportunities for both.”

    “I think our project sits right in the mix of a number of great researchers doing really important work on what the potential adaptations of corals to a future ocean may be,” Moeller said. “And with this detailed understanding, we’ll be better equipped to understand reefs elsewhere, and even extend the knowledge to other systems.”

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition


    UC Santa Barbara Seal
    The University of California, Santa Barbara (commonly referred to as UC Santa Barbara or UCSB) is a public research university and one of the 10 general campuses of the University of California system. Founded in 1891 as an independent teachers’ college, UCSB joined the University of California system in 1944 and is the third-oldest general-education campus in the system. The university is a comprehensive doctoral university and is organized into five colleges offering 87 undergraduate degrees and 55 graduate degrees. In 2012, UCSB was ranked 41st among “National Universities” and 10th among public universities by U.S. News & World Report. UCSB houses twelve national research centers, including the renowned Kavli Institute for Theoretical Physics.

     
  • richardmitnick 10:27 am on August 3, 2019 Permalink | Reply
    Tags: "Star Light Star Bright", Pulsating stars, Scientists hadn’t previously predicted the existence of these stars., , UCSB- University of California Santa Barbara,   

    From UC Santa Barbara: “Star Light, Star Bright” 

    UC Santa Barbara Name bloc
    From UC Santa Barbara

    August 1, 2019
    Harrison Tasoff

    Scientists discover a new type of pulsating star.

    1
    The nebula remains of a dead giant star surround the remaining subdwarf O star, another kind of hot subdwarf.
    Photo Credit: European Southern Observatory

    Scientists can tell a lot about a star by the light it gives off. The color, for example, reveals its surface temperature and the elements in and around it. Brightness correlates with a star’s mass, and for many stars, brightness fluctuates, a bit like a flickering candle.

    A team of scientists led by UC Santa Barbara researcher Thomas Kupfer recently discovered a new class of these pulsators that vary in brightness every five minutes. Their results appeared in The Astrophysical Journal Letters.

    “Many stars pulsate, even our sun does on a very small scale,” said Kupfer, a postdoctoral scholar at UC Santa Barbara’s Kavli Institute for Theoretical Physics (KITP).

    A true pulsator can vary in brightness by some 10% due to a periodic change in its temperature, radius or both. “Those with the largest brightness changes are usually radial pulsators, ‘breathing’ in and out as the entire star changes size,” he explained. By studying pulsations in detail, scientists can learn about these stars’ interior properties.

    Initially, Kupfer and his colleagues at Caltech were searching for binary stars with periods less than an hour in observations from the Zwicky Transient Facility, a sky survey at the Palomar Observatory near San Diego.

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

    Edwin Hubble at Caltech Palomar Samuel Oschin 48 inch Telescope, (credit: Emilio Segre Visual Archives/AIP/SPL)

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

    Four stood out due to large changes in their brightness over just a few minutes. Follow-up data quickly confirmed that they were indeed pulsators, not binary pairs.

    Working with his Caltech collaborators, alongside former UC Santa Barbara doctoral student Evan Bauer and KITP Director Lars Bildsten, Kupfer has now identified the stand-out stars as hot subdwarf pulsators. A subdwarf is a star about one-tenth the diameter of the sun with a mass between 20 and 50% that of sun. They’re incredibly hot — up to 90,000 degrees Fahrenheit, compared to the sun’s 10,000 F. “These stars have certainly completed fusing all of the hydrogen in their core into helium, explaining why they are so small and can oscillate so rapidly,” said Bildsten.

    The discovery came as a surprise. Scientists hadn’t previously predicted the existence of these stars, Kupfer explained, but in retrospect they fit well into the leading models of stellar evolution.

    Because of the stars’ low masses, the team believes they started life as typical sun-like stars fusing hydrogen to helium in their cores. After exhausting the hydrogen in their cores, the stars expanded into the red giant stage. Usually, a star will reach its largest radius and begin fusing helium deep in the core. However, the scientists think these newly discovered stars had their outer material stolen by a companion before the helium became hot and dense enough to fuse.

    In the past, hot subdwarfs were almost always related to stars which became red giants, started fusing helium in their cores, and then got stripped by a companion. The new findings indicate that this group includes different types of stars. “Some do helium fusion and some don’t,” Kupfer said.

    The stars’ pulsations allow scientists to probe their masses and radii and compare these measurements to stellar models, something that was not otherwise possible previously. “We were able to understand the rapid pulsations by matching them to theoretical models with low mass cores made of relatively cold helium,” said Bauer.

    “Sky surveys are transforming astronomy, and the Zwicky Transient Facility is helping pioneer this approach,” says the National Science Foundation ‘s Richard Barvainis, who oversees the agency’s grants in support of the facility. “This latest result is a perfect example — by watching distant stars pulsate over a matter of mere minutes, astronomers have gained unexpected insights into stellar evolution.”

    Kupfer believes there’s more to come. “I expect that these large, time-domain surveys like the Zwicky Transient Facility will bring many unexpected discoveries in the future,” he said.

    These research efforts at UC Santa Barbara are supported by the National Science Foundation, as well as the Gordon and Betty Moore Foundation. The Zwicky Transient Facility is funded by the National Science Foundation, NASA and the Heising-Simons Foundation. Other contributing institutions include Caltech, the University of Washington, the University of Maryland, the Humboldt University of Berlin, the Weizmann Institute of Science and Boston University, as well as an international collaboration of additional partners.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition


    UC Santa Barbara Seal
    The University of California, Santa Barbara (commonly referred to as UC Santa Barbara or UCSB) is a public research university and one of the 10 general campuses of the University of California system. Founded in 1891 as an independent teachers’ college, UCSB joined the University of California system in 1944 and is the third-oldest general-education campus in the system. The university is a comprehensive doctoral university and is organized into five colleges offering 87 undergraduate degrees and 55 graduate degrees. In 2012, UCSB was ranked 41st among “National Universities” and 10th among public universities by U.S. News & World Report. UCSB houses twelve national research centers, including the renowned Kavli Institute for Theoretical Physics.

     
  • richardmitnick 4:19 pm on March 6, 2019 Permalink | Reply
    Tags: An atom-defect hybrid quantum system, , , Coherence in quantum behavior, If you can see things on smaller scales with better sensitivity than anybody else you’re going to find new physics, In the experiment we will have an atom on the diamond surface that couples to a shallow subsurface NV center inside the material in a highly controlled cryogenic and ultra-high vacuum environment, Key to this technology is the nitrogen-vacancy (NV) center in diamond an extensively studied point defect in diamond’s carbon atom lattice, , , , , The physical and materials knowledge gained by mastering the interface of such a hybrid system would contribute to the development of quantum computing systems, The technique is reminiscent of molecular beam epitaxy (MBE) a method of “growing” a material atom-by-atom on a substrate, This project is a “natural fit” for UC Santa Barbara say the researchers due to the campus’s strengths in both physics and materials sciences, To Hold Without Touching, UCSB- University of California Santa Barbara   

    From UC Santa Barbara: “Sensing Disturbances in the Force” 

    UC Santa Barbara Name bloc
    From UC Santa Barbara

    March 5, 2019
    Sonia Fernandez

    UC Santa Barbara researchers receive U.S. Department of Energy grant to build atom-defect hybrid quantum sensor.

    1

    It will be a feat of engineering and physics at the smallest scales, but it could open the biggest doors — to new science and more advanced technologies. UC Santa Barbara physicists Ania Jayich and David Weld, and materials scientist Kunal Mukherjee, are teaming up to build an atom-defect hybrid quantum system — a sensor technology that would use the power of quantum science to unlock the mysteries of the atomic and subatomic world.

    “We’re at this tipping point where we know there’s a lot of impactful and fundamentally exciting things we can do,” said Jayich, whose research investigates quantum effects at the nanoscale. The $1.5 million grant from the Department of Energy’s Office of Basic Sciences will kickstart the development of a system that will allow researchers an unusually high level of control over atoms while simultaneously leaving their “quantumness” untouched.

    “In this whole field of quantum technology, that has been the big challenge,” Jayich said. In the quirky and highly unintuitive world of quantum mechanics, she explained, objects can exist in a superposition of many places at once, and entangled elements separated by thousands of miles can be inextricably linked — phenomena which, in turn, have opened up new and powerful possibilities for areas such as sensing, computing and the deepest investigations of nature.

    However, the coherence that is the signature of these quantum behaviors — a state of information that is the foundation of quantum technology — is exceedingly fragile and fleeting.

    “Quantum coherence is such a delicate phenomenon,” Jayich said. “Any uncontrolled interaction with the environment will kill it. And that’s the whole challenge behind advancing this field — how do we preserve the very delicate quantumness of an atom or defect, or anything?” To study a quantum element such as an atom, one would have to interrogate it, she explained, but the act of measuring can also destroy its quantum nature.

    To Hold Without Touching

    Fortunately, Jayich and colleagues see a way around this conundrum.

    “It’s a hybrid atomic- and solid-state system,” Jayich said. Key to this technology is the nitrogen-vacancy (NV) center in diamond, an extensively studied point defect in diamond’s carbon atom lattice. The NV center is comprised of a vacancy created by a missing carbon atom next to another vacancy that is substituted with a nitrogen atom. With its several unpaired electrons, it is highly sensitive to and interactive with external perturbations, such as the minute magnetic or electric fields that would occur in the presence of individual atoms of interest.

    “In the proposed experiment, we would have an atom on the diamond surface that couples to a shallow, subsurface NV center inside the material, in a highly controlled, cryogenic and ultra-high vacuum environment,” Jayich explained. The diamond surface provides a natural trapping that allows researchers to more easily hold the atom in place — a challenge for many quantum scientists who want to trap individual atoms. Further, upon reading the state of the defect, one could understand the quantum properties of the atom under interrogation — without touching the atom itself and destroying its coherence.

    Previous methods aimed at interrogating individual adatoms (adsorbed atoms) relied on passing current through the atoms and necessitated metal surfaces, both of which, according to Jayich, reduce quantum coherence times.

    “The past several decades of work in atomic physics have resulted in tools that allow exquisite quantum control of all degrees of freedom of atomic ensembles, but typically only when the atoms are gently held in a vacuum far away from all other matter,” added Weld. “This experiment seeks to extend this level of control into a much messier but also much more technologically relevant regime, by manipulating and sensing individual atoms that are chemically bonded to a solid surface.”

    With the hybrid system, Jayich said, it would be “very easy to talk to the NV center defect with light, and the atoms have the benefit of retaining quantum information for very long periods of time. So we have a system where we leverage the best of both worlds — the best of the atom and the best of the defect — and put them together in a way that’s functional.”

    A Foundation for Future Quantum Tech

    Looking forward, the state-of-the-art spatial resolution and sensitivity of this atom-defect hybrid quantum system could offer researchers the deepest look at the workings of individual atoms, or structures of molecules at nanometer- and Angstrom scales.

    “If you can see things on smaller scales with better sensitivity than anybody else, you’re going to find new physics,” Jayich said. The connections of microscopic structure to macroscopic behavior in materials synthesis could be elucidated. Quantum phenomena in condensed matter systems could be probed. Proteins that have evaded structural determination — such as membrane proteins — could be studied.

    This project is a “natural fit” for UC Santa Barbara, say the researchers, due to the campus’s strengths in both physics and materials sciences. The technique is reminiscent of molecular beam epitaxy (MBE), a method of “growing” a material atom-by-atom on a substrate.

    “There is a strong tradition of materials deposition at UCSB, ranging from metals, semiconductors to novel electronic materials,” Mukherjee said of the campus’s long record of materials growth and world-class MBE facilities. Among the first few atoms they intend to study are rare-earth types such as holmium or dysprosium “as they have unpaired electrons which are protected from environmental interactions by the atomic structure,” noted Mukherjee, adding that he is “particularly excited” about the challenge of removing the atoms from and resetting the diamond surface without breaking vacuum.

    Additionally, the physical and materials knowledge gained by mastering the interface of such a hybrid system would contribute to the development of quantum computing systems. According to Jayich, future practicable quantum computers would likely be a hybrid of several elements, similar to how conventional computers are a mix of magnetic, electronic and solid-state components.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    UC Santa Barbara Seal
    The University of California, Santa Barbara (commonly referred to as UC Santa Barbara or UCSB) is a public research university and one of the 10 general campuses of the University of California system. Founded in 1891 as an independent teachers’ college, UCSB joined the University of California system in 1944 and is the third-oldest general-education campus in the system. The university is a comprehensive doctoral university and is organized into five colleges offering 87 undergraduate degrees and 55 graduate degrees. In 2012, UCSB was ranked 41st among “National Universities” and 10th among public universities by U.S. News & World Report. UCSB houses twelve national research centers, including the renowned Kavli Institute for Theoretical Physics.

     
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