It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Sunday, December 11, 2022
Strengthen oversight of risky research on pathogens
AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE (AAAS)
A recent guidance framework by the World Health Organization “reminds us of the continued lack of awareness and governance structures in many countries for life sciences research that may cause harm through accident or misapplication,” say Jaspreet Pannu and colleagues in this Policy Forum.
Pannu and colleagues are specifically referring to “dual use research of concern” (DURC), which outlines life sciences research that may be misapplied to pose a substantial biosecurity threat, and work proposing to enhance potential pandemic pathogens (ePPPs). The authors identify substantial gaps in biosecurity policies around DURC and ePPP studies and suggest approaches to address these gaps, including expanding the scope of pathogens to be governed by ePPP review to even those with modest virulence (like the virus that caused COVID-19 is) and making assessments of risks and benefits of DURC and ePPP work available to the public. “It is vital to get these policies right,” say the authors, “not only for the US, but to inspire policy development in other countries with growing life science and biotechnology sectors.”
IMAGE: NORTHEASTERN TIBET PLATEAU UPLIFT AND IMPACT ON PRECIPITATIONview more
CREDIT: MIAO YUNFA
The uplift of the Tibet Plateau is considered to be the main driving force behind evolution of the Asian monsoon-arid climate as well as biodiversity in the region. Surface elevation is the intuitive expression of tectonic uplift, but quantitative reconstruction has always been a difficult problem.
Plants are the primary producers in the surface ecosystem and their distribution is predominantly controlled by climate and topography. Pollen, i.e., reproductive cells retrieved from plants, have the advantage of large yield, easy preservation and good continuity, which is the "key" to discovering the past.
Now, a joint research team led by Prof. FANG Xiaomin from the Institute of Tibetan Plateau Research of the Chinese Academy of Sciences (CAS), Prof. MIAO Yunfa from the Northwest Institute of Eco-Environment and Resources of CAS and Prof. HUANG Kangyou from Sun Yat-sen University and Prof. HUANG Kangyou from Sun Yat-sen University has exploited the potential of pollen in paleoelevation reconstruction.
The researchers constructed a new paleoaltimetry based on four montane conifers (Tsuga, Podocarpus, Abies and Picea),thus allowing them to reconstruct the mid-range paleoelevation sequences of the northeastern Tibet Plateau since the middle Miocene. Their research reveals that the region experienced strong uplift about 11 to 7 Ma (million years ago) that exerted strong environmental effects.
The study, "A new biologic paleoaltimetry indicating Late Miocene rapid uplift of northern Tibet Plateau," was published in Science on Dec. 8.
The researchers used a total of 3,088 surface pollen samples to create a quantitative formula that converted the ratios of Tsuga, Podocarpus, Abies and Picea into elevation values.
After passing a reliability test in five Quaternary and six Miocene sites in the Tibet Plateau, as well as one near sea level in Japan, this formula was applied to the northeastern Tibet Plateau. The researchers looked at data beginning 16 Ma in two parallel series. The results showed elevations of ~1.3 km and ~0.4 km 16–14 Ma. Elevations rose rapidly to ~2.9 km and ~2.7 km 13–10 Ma, and to ~3.6 km at 8–7 Ma, respectively.
"The basin was ~1.1 km at 16–14 Ma and uplifted to 2.4 km at 12–10 Ma according to the newly discovered plant fossils based on the Climate-Leaf Analysis Multivariate Program," said Prof. MIAO.
Moreover, the researchers used the regional climate model RegCM 4.6 to quantitatively assess the influence of altitude on precipitation. They found that when the northeastern Tibet Plateau was reduced to one-third of its current elevation, annual precipitation in this region was reduced by more than 50%, while precipitation in the Himalayas in the south and Hengduan Mountains in the southeast would increase by 50% and 150%, respectively. This precipitation eventually supported the rich biodiversity in this region.
This study shows that climate effects produced by the uplift of the northeastern Tibet Plateau have affected the climate and biological evolution of the region.
A new biologic paleoaltimetry indicating Late Miocene rapid uplift of northern Tibet Plateau
ARTICLE PUBLICATION DATE
8-Dec-2022
Story tips from the Department of Energy’s Oak Ridge National Laboratory, December 2022
Naturally derived materials fit for 3D printing; Next-gen hydropower starts with testing; Long-haul trucking meets megawatt-scale charging; New insights advance atomic-scale manufacturing
IMAGE: RESEARCHERS FOUND THAT MODERATE LEVELS OF ASH — SOMETIMES FOUND AS SPHERES IN BIOMASS — DO NOT SIGNIFICANTLY AFFECT THE MECHANICAL PROPERTIES OF BIOCOMPOSITES MADE UP OF CORN STOVER, SWITCHGRASS AND PLA THERMOPLASTIC.view more
CREDIT: ANDY SPROLES/ORNL, U.S. DEPT. OF ENERGY
Naturally derived materials fit for 3D printing
Biocomposites comprising corn stover, switchgrass prove their mettle
The presence of minerals called ash in plants makes little difference to the fitness of new naturally derived compound materials designed for additive manufacturing, an Oak Ridge National Laboratory-led team found.
When mixed with polylactic acid, fibers sourced from corn stover and switchgrass yielded biocomposites with satisfactory properties for 3D printing. In fact, the presence of ash spheres appeared to improve the flow of material for extrusion printing, said ORNL’s Xianhui Zhao.
“We went as high as 12% ash content on our corn stover biocomposite and found mechanical properties like stress and strain tolerance and tensile strength to be acceptable,” Zhao said.
The research enables a use for high-ash biomass residue from biorefining that could lower the overall cost of producing sustainable fuels and materials.
Next steps include exploring more biomass materials and testing the composites in a large-volume printer at ORNL. — Stephanie Seay
Technology to retrofit nonpowered dams such as the Lake Sequoyah Dam in North Carolina could be tested before deployment to ensure performance and reliability.
CREDIT
Scott DeNeale/ORNL, U.S. Dept. of Energy
Next-gen hydropower starts with testing
National full-scale test facilities could spur adoption of new clean energy technologies
Researchers at Oak Ridge National Laboratory have identified a key need for future hydropower innovations – full-scale testing – to better inform developers and operators before making major investments.
In a new report, ORNL outlines the benefits of establishing a network of national hydropower testing facilities to demonstrate new clean energy technologies and encourage early adoption.
To meet the growing demand for sustainable and renewable energy, existing hydropower facilities are investing in more flexible powertrains, expanding storage capabilities and improving their environmental footprint. New small hydropower development, such as retrofits of nonpowered dams, also aims to reduce costs through advanced manufacturing methods and innovative designs. These new technologies must be proven to first adopters, and testing at relevant scale is a critical step.
“Accessible testing would encourage operators to deploy water power technologies and fuel new research,” said ORNL’s Mirko Musa. “A national testing facility can provide validation or a safe place to fail, accelerating innovation and adoption.” — Mimi McHale
CAPTION
A multiport design allows a utility to easily interface with an EV truck stop to provide fast charging at megawatt scale.
CREDIT
Andy Sproles/ORNL, U.S. Dept. of Energy
Long-haul trucking meets megawatt-scale charging
Future EV truck stop designed to smooth high demand on electric grid
Transitioning long-haul trucks from diesel to electric power will require convenient ways to rapidly recharge electric vehicle batteries at power-plant scale. Researchers at Oak Ridge National Laboratory have designed architecture, software and control strategies for a futuristic EV truck stop that can draw megawatts of power and reduce carbon emissions.
The station’s design uses solar arrays and batteries, which generate and store enough power to handle the unpredictable load swings from recharging these large power plants on wheels. The software manages the system to draw a steady, predictable flow of power from the grid. The team fine-tuned the complex control hierarchy using real-time simulation, then verified those results with electronics in the lab.
“The next phase is looking at how to coordinate multiple stations in a network along the interstate,” said ORNL’s Radha Krishna Moorthy. Paired with advances in low- and zero-carbon fuels, electrification can help reduce the trucking industry’s carbon footprint.
When an electron beam drills holes in heated graphene, single-atom vacancies, shown in purple, diffuse until they join with other vacancies to form stationary structures and chains, shown in blue.
CREDIT
Ondrej Dyck/ORNL, U.S. Dept. of Energy
New insights advance atomic-scale manufacturing
Graphene’s unexpected resilience at higher temperatures results when single-atom vacancies roam
Oak Ridge National Laboratory researchers serendipitously discovered when they automated the beam of an electron microscope to precisely drill holes in the atomically thin lattice of graphene, the drilled holes closed up. They expected the heat to make atoms easier to remove, but they saw the opposite effect.
“Graphene appeared impervious to the electron beam,” said Ondrej Dyck, who co-led the study with Stephen Jesse at ORNL’s Center for Nanophase Materials Sciences. Jesse added, “It heals locally, like the (fictitious) liquid-metal T-1000 in the movie Terminator 2: Judgment Day.”
Theory-based computations performed on the lab’s Summit supercomputer, led by ORNL’s Mina Yoon, explained the quasi-metal’s healing ability: Single atomic vacancies zip through the heated graphene until they meet up with other vacancies and become immobilized.
“Similar processes are likely to extend to other 2D materials,” Dyck said.
“Controlling such processes could help us realize graphene’s promise for quantum information science,” said Jesse.
The researchers are applying this new knowledge to guide creation of atomic-scale devices.
IMAGE: IN “EX MACHINA: COEVOLVING MACHINES & THE ORIGINS OF THE SOCIAL UNIVERSE,” SFI EXTERNAL PROFESSOR JOHN H. MILLER MELDS IDEAS FROM THE STUDY OF GAMES, THE FUNDAMENTALS OF COMPUTATION, AND DARWIN'S THEORY OF EVOLUTION TO LOOK AT DYNAMIC SOCIAL SYSTEMS THROUGH A COMPUTATIONAL LENS.view more
CREDIT: SANTA FE INSTITUTE PRESS
Earth is full of examples of social behavior. When individual bacteria, insects, primates, and even self-driving cars make productive choices about their interactions with other individuals, that’s sociality. We can trace social behavior back to the unicellular organisms that became the building blocks for life on our planet. And humans, by becoming social, gained a great advantage in the evolutionary race for survival. If we could rewind Earth’s clock, would social behavior emerge yet again, and could we expect to find it elsewhere in the Universe? “Probably yes,” concludes a new book from SFI Press.
In “Ex Machina: Coevolving Machines & the Origins of the Social Universe,” Santa Fe Institute's External Professor John H. Miller (Carnegie Mellon University) melds ideas from the study of games, the fundamentals of computation, and Darwin's theory of evolution to look at dynamic social systems through a computational lens. This novel approach, he writes, is like a time machine that allows us to observe and analyze the advent of social behavior — a question that cannot be answered using knowledge from one field alone.
“This work, at its core, embraces SFI’s way of doing science,” says Miller, who is an economist and social scientist. “The most interesting and important scientific questions are often found in between traditional fields.”
But when working across disciplines, even seemingly simple things — like defining social behavior — can be challenging, says Miller. “Different scholars have very different notions about whether it can occur across species, if it requires special forms of intelligence, and so on.” His ultimate definition was fairly general — “a relief to dog owners everywhere,” he says — and it allows the possibility that social behavior could have emerged early in the history of life on Earth.
To answer questions about the emergence of sociality, Miller uses finite automata, which are simple computing machines that can respond to the inputs produced by other automata and evolve inside of a computer. The computations captured by the finite automata illustrate how much interaction and “thought” it takes for a system to become social, providing rich insights into the complex and multifaceted nature of social behavior. Miller began working on the core ideas presented in the book at SFI when he was a postdoc — the Institute’s first — more than thirty years ago. But only recently, aided by dramatic advances in computer power, could he realize the project.
The book became his path to discovery: a way for Miller to explore and understand, with a deeper vision, what it takes to make a system social. It also provided an opportunity to answer questions about the origins of social behavior, which Miller had raised in his 2007 book with Scott Page, “Complex Adaptive Systems.”
This new project offers readers unique and technical insights into the emergence of social behavior in a system. His work reveals that systems can change from asocial to social, or vice versa, as they cross certain thresholds. “If agents are very limited in their ability to process information — to make choices or be ‘thoughtful’ — or in how much they interact with one another, the system falls into asocial outcomes,” says Miller. “Surprisingly, even though these systems are driven by small evolutionary changes, the movement from asocial to social (and back again) can happen very quickly — revolutions by evolution.”
Understanding these thresholds of social behavior might not only explain how social life came to be, but also give us insights into social upheavals such as political movements and revolutions, the rapid acceptance of new social norms, and even the emergence or collapse of an entire social order. Such events can lead to profound and rapid transitions that ultimately define our collective future.
IMAGE: ILLUSTRATION DEPICTING THE MECHANISM AND DISTRIBUTION OF ANTIDOTE AND POISON EXPRESSION. AT THE START OF MEIOSIS, BOTH PROTEINS ARE EXPRESSED. LATER, ANTIDOTE IS ONLY FOUND OUTSIDE OF SPORES WHILE POISON PROTEIN IS UBIQUITOUS THROUGHOUT. FINALLY, THE MATURE SPORES THAT INHERIT WTF4 CONTAIN POISON AND ANTIDOTE, WHILE THE OTHER SPORES ARE DESTROYED.view more
CREDIT: STOWERS INSTITUTE FOR MEDICAL RESEARCH
KANSAS CITY, MO—Dec. 7, 2022—New findings from the Stowers Institute for Medical Research uncover critical insights about how a dangerous selfish gene—considered to be a parasitic portion of DNA—functions and survives. Understanding this dynamic is a valuable resource for the broader community studying meiotic drive systems.
A new study, published in PLoS Genetics on Dec. 7, 2022, reveals how a selfish gene in yeast uses a poison-antidote strategy that enables its function and likely has facilitated its long-term evolutionary success. This strategy is an important addition for scientists studying similar systems including teams that are designing synthetic drive systems for pathogenic pest control. Collective and collaborative advancement on understanding drive may one day lead to the eradication of pest populations that harm crops or even humans in the case of vector borne diseases.
“It’s quite dangerous for a genome to encode a protein that has the capacity to kill the organism,” said Stowers Associate Investigator SaraH Zanders, Ph.D. “However, understanding the biology of these selfish elements could help us build synthetic drivers to modify natural populations.”
Drivers are selfish genes that can spread in a population at higher rates than most other genes, without benefiting the organism. Previous research from the Zanders Lab revealed that a driver gene in yeast, wtf4, produces poison protein capable of destroying all offspring. However, for a given parent cell’s chromosome pair, drive is achieved when wtf4 is found only on one chromosome. The effect is a simultaneous rescue of only those offspring that inherit the drive allele, by delivering a dose of a very similar protein that counteracts the poison, the antidote.
Building upon this work, the study, led by former Predoctoral Researcher Nicole Nuckolls, Ph.D., and current Predoctoral Researcher Ananya Nidamangala Srinivasa in the Zanders Lab, discovered that differences in the timing of generating poison and antidote proteins from wtf4 and their unique distribution patterns within developing spores are fundamental to the drive process.
The team has developed a model they are continuing to investigate for how the poison acts to kill the spore—the equivalent of a human egg or sperm in yeast. Their results indicate that poison proteins cluster together, potentially disrupting proper folding of other proteins required for the cell to function. Because the wtf4 gene encodes both poison and antidote, the antidote is very similar in form and groups together with the poison. However, the antidote has an extra part that appears to isolate the poison-antidote clusters by bringing them to the cell’s garbage can, the vacuole.
To understand how selfish genes function during reproduction, the researchers looked at the beginning of spore formation and found poison protein expressed within all developing spores and the sac surrounding them, while the antidote protein was only seen in low concentration throughout the sac. Later in development, the antidote was enriched inside of the spores that inherited wtf4 from the parent yeast cell.
The researchers found that spores that inherited the driver gene manufactured additional antidote protein inside the spore to neutralize the poison and ensure their survival.
The team also discovered that a particular molecular switch that controls many other genes involved in spore formation also controls the expression of poison, but not antidote, from the wtf4 gene. The switch is essential for yeast reproduction and is inextricably linked to wtf4, helping to explain why this selfish gene is so successful at evading any attempts by the host to disable the switch.
“One of the reasons we are thinking these things have stuck around for so long – they’ve used this sneaky strategy of exploiting the same essential switch that turns on yeast reproduction,” said Nidamangala Srinivasa.
“If we could manipulate these DNA parasites to be expressed in mosquitoes and drive their destruction, it may be a way to control pest species,” said Nuckolls.
This work was funded by the Searle Award, the National Institutes of General Medical Sciences (awards: R00GM114436, DP2GM132936), the National Cancer Institute (award: F99CA234523), the Eunice Kennedy Shriver National Institute of Child Health and Human Development (award: F31HD097974) of the National Institutes of Health (NIH), and institutional support from the Stowers Institute for Medical Research. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.
About the Stowers Institute for Medical Research
Founded in 1994 through the generosity of Jim Stowers, founder of American Century Investments, and his wife, Virginia, the Stowers Institute for Medical Research is a non-profit, biomedical research organization with a focus on foundational research. Its mission is to expand our understanding of the secrets of life and improve life’s quality through innovative approaches to the causes, treatment, and prevention of diseases.
The Institute consists of 17 independent research programs. Of the approximately 500 members, over 370 are scientific staff that include principal investigators, technology center directors, postdoctoral scientists, graduate students, and technical support staff. Learn more about the Institute at www.stowers.org and about its graduate program at www.stowers.org/gradschool.
CAPTION
Progression of meiosis from initiation to eight hours (each row). Left and middle columns show antidote and poison protein distribution, respectively, as spores develop. Right column is the combined distribution of poison (cyan) and antidote (magenta) during spore development.
CREDIT
Stowers Institute for Medical Research
JOURNAL
PLoS Genetics
METHOD OF RESEARCH
Experimental study
SUBJECT OF RESEARCH
Cells
ARTICLE TITLE
S. pombe wtf drivers use dual transcriptional regulation and selective protein exclusion from spores to cause meiotic drive
Suicidal thoughts surged as people struggled with finances, isolation during COVID-19
Suicidal ideation increased to alarming levels in 2020, particularly among people who had trouble paying rent or who felt lonely.
The sudden economic fallout at the start of the COVID-19 pandemic affected millions of people and contributed to a three-fold rise in persistent or elevated depression in the United States. But the extent of this toll on mental health is still coming to light.
Now, a new study led by Boston University School of Public Health (BUSPH) researchers reveals that suicidal thoughts increased substantially, as well, during the pandemic.
Published in the journal PLOS One, the study found that suicidal ideation was nearly five times higher at the start of the pandemic and disproportionately affected people living in low-income households. People who had difficulty paying rent or who felt lonely—two problems that intensified during COVID due to social distancing to reduce spread of COVID-19 and the unprecedented shock to the economy—also reported a substantial rise in suicidal thoughts.
The study provides valuable insight into the short- and long-term mental health effects of the pandemic. As people continue to experience multiple COVID-related stressors, the researchers emphasize the need for policies and programs that provide financial and social support, particularly to vulnerable populations.
“Everyone felt the toll of mental distress from the challenges of the pandemic and unemployment crisis, and people who are low-income and housing insecure were most impacted,” says study lead and corresponding author Dr. Julia Raifman, assistant professor of health law, policy & management at BUSPH. “Policies and programs that help people stay in their homes and avoid economic hardship may make a big difference for improving mental health. It is also key to ensure that there are mental health services and supports for low-income children and adults.”
For the study, Raifman and colleagues examined nationally representative survey data on demographics, suicidality, and a variety of pandemic-related stressors, including COVID-19 illness and bereavement, income, job loss, financial distress, loneliness, and more. The data included responses from more than 1,400 participants in the COVID-19 Life Stressors Impact on Mental Health and Well-Being (CLIMB) survey from March 31, 2020 to April 13, 2020, and more than 5,000 participants in the 2017-2018 National Health and Nutrition Examination Survey (NHANES).
The prevalence of suicidal thoughts increased from 3.4 percent in 2017-2018 pre-pandemic, to 16.3 percent after the start of the pandemic. The spike was greatest among participants who earned less than $20,000 each year, Hispanic participants, and participants ages 18 to 29. Suicidal ideation also burdened 31 percent of people who had trouble paying their rent, and 25 percent of people who struggled with loneliness.
“It was striking that around a quarter of low-income persons, Hispanic persons, and people ages 18-29 years reported suicidal ideation in 2020,” says study coauthor Dr. Catherine Ettman, postdoctoral fellow in the Department of Mental Health at Johns Hopkins Bloomberg School of Public Health. “These findings add evidence to the growing body of work showing the mental health disparities experienced during the pandemic across asset and demographic groups. The early pandemic particularly affected the mental health of young people, persons with low assets, and groups that have been traditionally marginalized by society.”
Job loss was not associated with suicidal ideation in the CLIMB survey, but further research could provide insight into the potential effects of prolonged COVID-related unemployment, and whether suicidality risks differ by wealth. In previous work, the researchers found links between assets and mental health, suggesting that people with higher income and savings are less likely to experience depression, a risk factor for suicidality.
“We are now starting to see the long term consequences of the COVID-19 pandemic,” says study coauthor Dr. Salma Abdalla, research fellow at BUSPH. “The effects of the pandemic will be felt for a long time, particularly for young persons who will navigate the health and mental health consequences of this moment across the lifecourse.”
Policies that target populations experiencing financial distress and social isolation could serve as a valuable tool for suicide prevention, as well as policies that strengthen firearm restrictions—the primary means of suicide deaths—the researchers say.
“I hope we may see more research on how policies and programs that jointly maximize health and economic well-being,” Dr. Raifman says. “After the period when we conducted this study, Congress implemented stimulus checks, the expanded child tax credit, and unemployment insurance expansion that led to record reductions in poverty—benefiting health and reducing economic hardship for millions of Americans. This shows us the best of what is possible with policies, and I hope we will see more enduring federal and state investments in similar policies.”
The study's senior author was Dr. Sandro Galea, BUSPH dean and Robert A. Knox Professor. The study was also coauthored by Dr. Lorraine Dean, associate professor in the Departments of Epidemiology and Health Policy and Law at Bloomberg SPH and at Johns Hopkins University School of Medicine; Alexandra Skinner, a doctoral student at Brown University School of Public Health; and Colleen Barry, inaugural dean of the Cornell Jeb E. Brooks School of Public Policy.
**
About Boston University School of Public Health Founded in 1976, Boston University School of Public Health is one of the top five ranked private schools of public health in the world. It offers master's- and doctoral-level education in public health. The faculty in six departments conduct policy-changing public health research around the world, with the mission of improving the health of populations—especially the disadvantaged, underserved, and vulnerable—locally and globally.
IMAGE: PALOMAR OBSERVATORY’S HALE TELESCOPE WILL RECEIVE THE HIGH-RATE DATA DOWNLINK FROM THE DSOC FLIGHT TRANSCEIVER.view more
CREDIT: CALTECH/PALOMAR OBSERVATORY
Researchers report new results from the NASA Deep Space Optical Communications (DSOC) technology demonstration project, which develops and tests new advanced laser sources for deep-space optical communication. The ability to perform free-space optical communication throughout the solar system would go beyond the capabilities of the radio communication systems used now and provide the bandwidth necessary for future space missions to transmit large amounts of data, including high-definition images and video.
The demonstration system consists of a flight laser transceiver, a ground laser transmitter and a ground laser receiver. The downlink transmitter has been installed on the Psyche spacecraft, which will travel to a unique metal asteroid also called Psyche, which orbits the Sun between Mars and Jupiter.
Malcolm. W. Wright, from the Jet Propulsion Laboratory, California Institute of Technology, will present the functional and environmental test results of the DSOC downlink flight laser transmitter assembly and ground uplink transmitter assembly at the Optica Laser Congress, 11 – 15 December 2022.
Validating deep space optical communications will allow streaming back high-definition imagery during robotic and manned exploration of planetary bodies, utilizing resources comparable to state-of-art radio-frequency telecommunications.
Transmitting into deep space
Although free-space optical communications from space to ground have been demonstrated at distances as far away as the moon, extending such links to deep space ranges requires new types of laser transmitters. The downlink flight laser must have a high photon efficiency while supporting near kilowatt peak power. The uplink laser requires multi-kilowatt average powers with narrow linewidth, good beam quality and low modulation rates.
The flight laser transmitter assembly uses a 5 W average power Er-Yb co-doped fiber-based master oscillator power amplifier laser with discrete pulse widths from 0.5 to 8 ns in a polarized output beam at 1550 nm with an extinction ratio of more than 33 dB. The laser passed verification and environmental tests before being integrated into spacecraft. End-to-end testing of the flight laser transmitter with the ground receiver assembly also validated the optical link performance for a variety of pulse formats and verified the interface to the DSOC electronics assembly.
Launching a new approach
The ground uplink transmitter assembly can support optical links with up to 5.6 kW average power at 1064 nm. It includes ten kilowatt-class continuous wavelength fiber-based laser transmitters modified to support the modulation formats. A remotely placed chiller provides thermal management for the lasers and power supplies. The uplink laser will also provide a light beacon onto which the flight transceiver can lock.
“Using multiple individual laser sources that propagate through sub-apertures on the telescope’s primary mirror relieves the power requirement from a single source,” said Wright. “It also allows atmospheric turbulence mitigation and reduces the power density on the telescope mirrors.”
Now that spacecraft-level testing is complete, the Psyche spacecraft — with the flight laser transceiver aboard — will be integrated into a launch vehicle. The DSOC technology demonstration will begin shortly after launch and continue for one year as the spacecraft travels away from Earth and eventually performs a flyby of Mars.
About the 2022 Optica Laser Congress and Exhibition
The Laser Congress provides a comprehensive view of the latest advances in solid-state laser development along with recent new applications. This year’s meeting will be presented 11 – 15 December 2022 in a hybrid meeting format to accommodate virtual (online) participation as well as in-person attendance at the Barcelona International Convention Center. Learn more.
About Optica
Optica (formerly OSA), Advancing Optics and Photonics Worldwide, is the society dedicated to promoting the generation, application, archiving and dissemination of knowledge in the field. Founded in 1916, it is the leading organization for scientists, engineers, business professionals, students and others interested in the science of light. Optica’s renowned publications, meetings, online resources and in-person activities fuel discoveries, shape real-life applications and accelerate scientific, technical and educational achievement. Discover more at: Optica.org
Oxytocin drives development of neural connections in adult-born neurons
Learning a new task, mastering a musical instrument or being able to adapt to the constantly changing environment are all possible thanks to the brain’s plasticity, or its ability to modify itself by rearranging existing neural networks and forming new ones to acquire new functional properties. This also helps neural circuits to remain healthy, robust and stable.
To better understand brain plasticity, a team of researchers at Baylor College of Medicine and Texas Children’ Hospital used mouse models to investigate how brain cells build connections with new neurons born in adult brains. Their findings, published in the journal Genes & Development, not only expand our understanding of brain plasticity but also open new possibilities for treating certain neurodevelopmental disorders and repairing injured circuits in the future.
“In this study, we wanted to identify new molecules that help new neurons build connections in the brain,” said corresponding author Dr. Benjamin R. Arenkiel, professor of molecular and human geneticsand neuroscience at Baylor and the Duncan Neurological Research Institute at Texas Children’s. “We worked with the olfactory bulb, the part of the brain that is involved in the sense of smell. In mice, the olfactory bulb is a highly plastic sensory area and has a remarkable capacity to maintain plasticity into adulthood via continuous integration of adult-born neurons. We discovered that oxytocin, a peptide, or short protein, produced in the brain, drives events that contribute to neural circuit plasticity.”
The researchers discovered that the levels of oxytocin increase in the olfactory bulb, peaking at the time the new neurons incorporate themselves into neural networks. Using viral labeling, confocal microscopy and cell-type specific RNA sequencing, the team discovered that oxytocin triggers a signaling pathway – a series of molecular events inside cells – that promotes the maturation of synapses, that is, the connections of newly integrated adult-born neurons. When the researchers eliminated the oxytocin receptor, the cells had underdeveloped synapses and impaired function.
“Importantly, we found that synapse maturation occurs by regulating the morphological development of cells and the expression of a number of structural proteins,” said Arenkiel, a MacNair Scholar at Baylor.
“The most exciting aspect of this study is that our findings suggest that oxytocin drives development and synaptic integration of new neurons within the adult brain, directly contributing to adaptability and circuit plasticity,” said first author Brandon T. Pekarek, a graduate student – research assistant in the Arenkiel lab.
The findings, which are relevant to all mammals, including humans, open new possibilities to improve neurological conditions. “Oxytocin is normally present in our brain, so if we understand how to turn it on or off or mobilize it, we can help keep our circuit connections healthy by promoting the growth of underdeveloped connections or strengthening new ones,” Arenkiel said. “Our findings also suggest that oxytocin could promote the growth of new neurons to repair damaged tissue. Further studies are needed to explore these possibilities.”
Mikhail Kochukov, Brittney Lozzi, Timothy Wu, Patrick J. Hunt, Burak Tepe, Elizabeth Hanson Moss, Evelyne K. Tantry, Jessica L. Swanson, Sean W. Dooling, Mayuri Patel, Benjamin D.W. Belfort, Juan M. Romero, Suyang Bao and Matthew C. Hill contributed to this work. The authors are affiliated with Baylor College of Medicine and/or Texas Children’s Hospital.
This work was supported by the McNair Medical Institute, NINDS grant R01NS078294, an AHA grant and NICH grant U54HD083092.
