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When the COVID-19 pandemic forced medical students out of classrooms and clinical rotations this time last year, the state of Georgia's only public medical school had to quickly rethink its traditional curriculum.

Faculty and staff at the Medical College of Georgia at Augusta University were able to quickly adapt and provide an online platform for learning about the pandemic and initiating student-led service projects to aid frontline workers and help educate the public, MCG faculty and students write in a review article in the journal Medical Science Educator.

The University System of Georgia suspended in-classroom learning in mid-March, so faculty at MCG shifted first- and second-year in person classes to online. Lectures were replaced with recorded materials and other in-person activities like small groups, clinical skills training and anatomy labs were either suspended or transitioned online.

"Our faculty were able to make that transition as smooth as possible by constantly listening to students' feedback - asking what worked and what didn't," says second-year student Amanda Delgado, one of the article's co-authors.

Later in March, the Association of American Medical Colleges called for a "pause" in patient contact and clinical training for third- and fourth-year medical students across the country. The medical school's administration knew that "steps to ensure an enriching alternative to clinical education" had to be taken, the students write.

The medical school's solution? Stand up a novel online Pandemic Medicine Elective -- one it already had a model for.

An existing summer program, Areas of Concentration, had been traditionally offered to rising second-year students as a four-week elective that covered topics like ethics, leadership, global and public health, health policy and artificial intelligence and machine learning. Faculty with extensive knowledge in each field facilitated lectures on each topic.

When the COVID-19 pandemic hit, MCG's academic administration was able to restructure that program to create the new elective. It consisted of four weeks of instruction -- two hours of lectures, four days a week, and one day dedicated to experiential learning and service. Teams of physicians and educators from across the medical school and guest lecturers from other colleges and universities collaborated to educate students on topics ranging from the basic science of SARS-CoV-2 to the challenges it created for health care and the public sector, from how to deliver health care in a crisis to professional and personal responsibility.

The second version of the elective, launched in mid-May, was offered to rising second-year students, as well as a limited number of students and oral and maxillofacial surgery residents from the Dental College of Georgia and some students from The Graduate School. "With summer research programs cancelled, students were eager to engage with faculty and content experts on relevant health topics," the students write.

The elective also offered rich experiences like the listening to interviews with physicians battling the pandemic in China and Germany and participating in a live question and answer session with a physician who compared her experience working in Guinea during the Ebola crisis to that of fighting COVID-19 in New York City.

As the pandemic raged on through the summer, a third iteration -- called a "selective" because it was offered to a select group of students whose clinical rotations were being delayed -- was launched in late June and focused on preparing students for what the clinical environment would look like when they returned to clinical activities during the pandemic. "While (it) included topics from previous iterations of the elective, it focused more heavily on the impact of the pandemic on providers and their delivery of care," says MCG infectious disease physician Dr. Rodger MacArthur, the article's senior author and the group's faculty advisor.

A common thread among each version of the elective was student-led service learning projects. Some of those included developing a website to publish local COVID-19 news and resources, aiding frontline workers by purchasing and delivering N95 masks, gloves and face shields, raising $15,000 to purchase personal protective equipment and collaborating with musicians to provide them comfort. At the medical school's regional campuses across the state, students worked with public health departments to help with contact tracing and work in their call centers.

By the completion of the elective, a total of 6,198 service hours had been logged by MCG students.

"So many people rose to the occasion and everyone worked together to help us continue our education and help our communities at the same time," says second-year student Joseph Elengickal, the article's corresponding author.

Next steps include conducting surveys and focus groups on students' experiences during the elective with an eye toward improving students' other educational experiences.

Every year 600-900 million tons of carbon flow through rivers to the ocean either as particles or in dissolved form. Researchers have known for a long time that this does not represent the total amount of carbon that gets transported from the land to the ocean. But the remaining contributors mostly from coastal ecosystems, such as carbon-rich mangrove forests, and from groundwater discharge into the ocean have been notoriously difficult to measure.

A new study published in the journal Global Biogeochemical Cycles and spearheaded by Dr. Eun Young Kwon, project leader at the IBS Center for Climate Physics South Korea provides new estimates of this elusive component of the global carbon cycle. The study makes use of the existence of two stable carbon isotopes, 12C and 13C, with the latter being slightly heavier, because it has one more neutron in its nucleus. The concentration ratio between these two carbon isotopes (referred to as ?13C) provides a means to track carbon through the different components of the carbon cycle, including the atmosphere, oceans, river systems and the biosphere. Knowing the typical ?13C value of land biosphere and for coastal vegetation, one can now track how this quantity gets diluted in the oceans. "The carbon isotope values act like an invisible dye that tells us something about the source where it came from and how much got released initially" says Dr. Kwon, lead author of the study.

By using oceanic observations of ?13C and estimates of the ocean currents, Dr. Kwon and her international team were able to calculate how much carbon would have to come from the land to explain the ocean data. The calculations are a bit more complicated because carbon can also get deposited in the deep ocean as sediment or outgas to the atmosphere. Furthermore, fossil fuel burning also changes the ?13C of atmospheric and eventually oceanic carbon.

After accounting for these effects, the authors were up for a surprise: they found much higher numbers for the land to ocean carbon transfer of 900-1900 million tons per year (see Figure). Most of non-riverine carbon inputs of about 300-1300 million tons of carbon per year occur mostly along the coastlines of the Indian and Pacific Oceans. "This is consistent with the idea that groundwater discharge and coastal ecosystems, the so-called blue carbon, play a fundamental role in the global carbon cycle" says Dr. Kwon.

One of the remaining open questions is which oceanic processes are responsible for carrying the dissolved carbon from the coastal zones to the open ocean, where part of it outgases back to the atmosphere. "This question will be addressed in future with a series of new earth system model simulations that we just conducted on our supercomputer Aleph", says Axel Timmermann, co-author of the study and Director of the IBS Center for Climate Physics.

Statisticians have calculated the probability of ships of different Polar Ship Categories becoming beset in ice along the Northern Sea Route. Their data will help assess the risks of maritime traffic in the Arctic.

The results of the new study, published recently in the Cold Regions Science and Technology journal, will support safer maritime transport planning and the prevention of oil spills. The results will also benefit authorities that regulate maritime traffic by providing a foundation for statutes and legislation. A comprehensive approach to computing helps shipping companies plan transport routes.

Tankers more common on the Northern Sea Route

The Northern Sea Route is attracting more tankers and cargo ships travelling from Russia and Asia to Europe, and traffic is expected to increase along the route in tandem with global warming (Figure 1).

In the winter, the sea is frozen over, making it inaccessible to ships of a lower Polar Ship Category without the assistance of an icebreaker. Ships can also become beset in ice in the spring and summer, leading to transport delays. At its worst, ice may force a vessel off its course so that it runs aground, with disastrous consequences.

"This is the first time a comprehensive risk assessment of a besetting event was performed using open data only," says Assistant Professor of Statistics Jarno Vanhatalo, head of the Environmental and Ecological Statistics group and director of the Master's Programme in Life Science Informatics at the University of Helsinki.

The researchers used satellite data on ice conditions in Arctic marine areas as well as open data sources on shipping.

"One of the biggest tasks required the merger of open datasets so that analyses could be conducted. This task was performed by Aalto University. The statistical analyses were carried out at the University of Helsinki, using a traditional generalised linear model, to which a Bayesian approach was applied," Vanhatalo explains.

Ice conditions on northern maritime routes

"If we know the ice conditions prevailing in a specific area, which can usually be ascertained from satellite images, we can make a prediction for, say, today and for each point along the Northern Sea Route," states Vanhatalo. The prediction indicates the probability of a ship of a particular type becoming beset in ice in a particular area (Figure 2).

The Polar Ship Category of a ship has a crucial impact on the probability of besetting. Ships of a lower category are most at risk, and many of them become beset in ice each year.

The researchers also analysed the effect of ice concentration on the probability of besetting. Ice concentration indicates the share of the sea covered by ice. In the winter, ice concentration is 100%, whereas in the spring and summer it varies from 0% to 100%, which means that the marine area is a mosaic of ice floes and open water.

The probability of a ship becoming beset in ice increases the longer the distance it travels in ice-covered waters and also increases significantly with higher ice concentrations. There are also considerable differences between ships of different Polar Ship Categories. For the best vessels, i.e., Category A ships, the probability of besetting on a journey of 3,000 nautical miles (NM) in 90%-100% ice concentration is just 0.04. Correspondingly, the probability for Category B ships is 7.5 times higher, or 0.3, whereas the probability for Category C ships is 22.5 times higher, or 0.9.

The newly published study is part of an international long-term research project funded by the Lloyd's Register Foundation and aimed at improving maritime safety. Launched in 2003, the project will conclude at the end of 2021. Participants in the CEARCTIC and CEPOLAR projects, headed by Aalto University, include not only the University of Helsinki, but also the Norwegian University of Science and Technology (NTNU), the Memorial University of Newfoundland in Canada, and the Hamburg University of Technology in Germany.

The University of Helsinki researchers have been responsible for assessing the impact of a potential oil spill on the Arctic environment and biotic communities. Previous publications have focused on species of organisms in the Kara Sea and the effects of an oil spill in the area. [link: https://www2.helsinki.fi/en/researchgroups/environmental-and-ecological-statistics/oil-spill-risk-analysis-in-the-arctic]

Although the research project is coming to a close, before the end of this year it will publish more statistical analyses of uncertainties associated with the modelling.

"Due to the limited measurement data available from Arctic marine areas, there are major uncertainties concerning shipping, living organisms and the behaviour of oil. Another major uncertainty relates to the natural stochasticity of highly unstable environmental conditions," Vanhatalo adds.

Another article currently being written explores the relative significances of factors affecting the overall risk as well as how risk analyses should be carried out and how the conclusions drawn differ depending on what is examined. Does the examination focus solely on the accident risk of vessels or also on the risk they pose to marine biotic communities? The results depend on whether both are examined separately or at the same time.

Other upcoming publications include summarising reports on the project as a whole and recommendations based on the research conducted.

Shipping provides the very foundation for world trade, by moving an estimated 11 billion tonnes of goods a year from where they are produced to where they will be used. From TVs to toasters, soap to sugar -- much of it moves over the waves.

Yet for ships plying the open ocean and for offshore industries, waves present an enormous challenge --because they can increase operational risks, reduce operating efficiency, and be dangerous if large enough and not handled well -- and they can be difficult to predict.

Ships can access information about wave heights, directions and frequency, but those data may be expensive to obtain or delayed because of satellite communication limitations, says Zhengru Ren, a postdoctoral fellow at the Norwegian University of Science and Technology's (NTNU) Department of Marine Technology and the research centre SFI MOVE.

Those challenges led Ren and his colleagues to take a different approach to estimating sea states, which is what mariners and researchers collectively call wave heights, frequencies and directions. The method is described in a new peer-reviewed article in Marine Structures.

Instead of relying on specialized meteorological instruments, the researchers used the movement of the ship itself to estimate wave conditions in real time.

"This method allows a real-time estimation without extra costs for measurement instruments. We believe that this technique is promising because it is general and works for almost all ships without extra cost," Ren said. "Another advantage is that it is very easy to apply in temporary scenarios."

The approach relies on cause and effect calculations, but not in the way you might think, says Roger Skjetne, a professor at NTNU's Department of Marine Technology who was senior author of the paper.

"In principle, the prediction algorithm is based on cause and effect, but in this case we measure the effect - the ship movements - and estimate the cause - the waves that affect the ship," Skjetne said. "If we do this for long enough, we're able to reconstruct the significant part of the wave spectrum."

One of the keys to understand what Ren and his colleagues did is to realize that a ship is asymmetric, meaning that it will rock or move differently based on the direction and the size of the waves it encounters.

Think of it like this: If a ship were perfectly round, like a ball, it would respond to waves pretty much the same way, except perhaps for direction.

But ships are shaped more like an ellipse with one flat end. That means the effect of the waves will be different, depending upon where the waves hit the ship. Another factor that affects the ship's movement will be the specific geometry of the ship's hull.

The researchers developed a mathematical approach to combine all of this information about the ship's geometry, dynamic motions, and wave influence, which can be calculated beforehand. They then combined this with mathematical formulas that are used to calculate information about waves from floating structures.

The researchers assumed that the ship was being kept in one location by a dynamic positioning system. A ship with a dynamic positioning system has several thrusters on its hull which work together to hold the ship at one location, based on GPS information.

But this wasn't quite enough to come up with the information that would be useful for mariners, Ren and his colleagues realized.

"This is an interesting and exciting research topic. But how to use extra information or ways to improve the estimates absorbed my thoughts," Ren said.

In the end, the researchers used two different mathematical techniques to fine-tune their calculations. One involved smoothing out the slopes of the waves a little differently, by using something called a Bézier surface.

The second involved optimizing the calculations for disturbances and errors that come from the vessel's responses to the waves.

But before the algorithm can be used in a shipboard computer to convert the ship motion sensor signals into the prevailing directional wave spectrum, in real-time, the ship has to have something called motion response amplitude operators (RAOs) available.

"These are mathematical transfer functions that are calculated beforehand, using ship design computer programs, in order to understand how certain waves result in movements (responses) of the ship," Skjetne said. "This makes it possible to invert the problem, by measuring the movements and then use the RAOs to say something about the incoming waves."

"We believe that this budget-friendly technique will be promising in future maritime industry," Ren said. "After improving the smoothness and robustness issues, the time spent on careful parameter tuning can be relaxed, making it easy to use on a given vessel. In turn, this ensures more efficient marine operations - which is what we aim for in the Centre for Research Based innovation on Marine Operations (SFI MOVE)."

Undocumented women in Finland access pregnancy care later than others. Yet, screening of infectious diseases at the early stages of pregnancy would be particularly important to these women, a new study carried out in Helsinki, Finland, shows. Conducted by the University of Eastern Finland and the University of Helsinki, the study on undocumented women's pregnancy care and childbirth was published in BMC Pregnancy and Childbirth.

Undocumented pregnant women constitute a vulnerable group of people who lack equal access to pregnancy care. Previous research has shown that undocumented migrants encounter difficulties in accessing health services, the onset of their prenatal care is delayed, and women have an increased risk for infectious diseases. Yet, with continuous prenatal care throughout pregnancy, it is possible to prevent pregnancy complications and arrange proper medical care and guidance when needed.

The new study examined the outcomes of pregnancy and childbirth of undocumented women attending the public maternity care in Helsinki, Finland, in 2014-2018. The study population consisted of 62 individual pregnancies. The majority, 61%, of undocumented women gained or sought access to pregnancy care only during their second or third pregnancy trimester. For the majority, 71%, pregnancy care was inadequate. Undocumented women had an average of five prenatal care visits, whereas other women had an average of 13 visits. In Finland, the national recommendation is 8-10 prenatal care visits during pregnancy.

Screening for infectious diseases during pregnancy was fairly successful in Helsinki. Almost all undocumented pregnant women were screened for HIV, hepatitis B, and syphilis. However, 57% of women were not screened for hepatitis C antibodies as recommended. HIV and hepatitis B were more common among undocumented pregnant women than other women in Finland.

"It would be very important to screen all undocumented women for infections at the early stages of pregnancy, so that possible antiviral medication can be initiated in time to prevent mother-to-child-transmission. This would be best safeguarded by guaranteeing undocumented people a legal right to health care," Infectious Diseases Physician Ville Holmberg says.

In Finland, undocumented people do not have a statutory right to health care and, consequently, to pregnancy care. However, Helsinki and a few other Finnish municipalities are providing undocumented women access to pregnancy care.

"We also need new innovative ways of promoting undocumented women's seeking of, and access to, care. Information should be made available extensively and not only in different languages, but also in plain language. Health care professionals should be provided with up-to-date information on the types of services available to undocumented women and children, and on the special characteristics associated with the treatment of undocumented people," Midwife Janita Tasa, MHS, says.

"By providing timely and adequate prenatal care to undocumented women, we can prevent pregnancy complications and the transmission of infectious diseases from mothers to children. Timely care is equitable, and it also reduces the costs of health care," Tasa says.

"Overall, the service users of Finnish maternity care are changing, as families with immigrant backgrounds are a rapidly growing group. So far however, we have very little research evidence on the impact of this change on traditional maternity care," says Professor Katri Vehviläinen-Julkunen.

Study finds that children who experienced housing loss in the 2011 Great East Japan Earthquake are more inclined to opt for short-term gratification

Tokyo - Living through a tragic event might make us more inclined to live for the moment, but not always in a good way. Research is looking into the psychological after-effects among children who survived the 2011 Great East Japan Earthquake, and a recent study may have made a connection: the children may forgo greater long-term reward for short-term pleasure.

Among the traumatic experiences in the quake and subsequent tsunami that killed almost 16,000 people, some survivors witnessed people washed away and had their houses destroyed. A study from Tokyo Medical and Dental University (TMDU) analyzed data collected in 2012-2014 on 3- to 5-year-old survivors of the disaster.

The researchers found that some of the children tended toward what's called "delay discounting behavior", or favoring smaller short-term rewards over larger rewards given later. The findings were published in PLOS ONE.

"The shock of being in a disaster can change our trust in the world, and this may lead to impatient behavior," study co-author Takeo Fujiwara says. "But we don't know a great deal about children who go through this process."

The children in the study were interviewed to uncover what trauma(s) they had experienced. They later took part in a time-investment exercise to gauge their ability to delay gratification. They were offered five tokens: one token equaled one candy now or two a month later. They were asked to assign each of the five to "now" or "one month later."

Among the various forms of trauma, which included losing a caregiver, witnessing the tsunami waves or fires, or seeing a dead body, the children whose had lost their housing had higher delay discounting. In other words, they assigned more tokens to "now," showing preference for smaller reward in the short term.

Interestingly, the researchers found no association between delay discounting and other traumas. So, why this association with housing loss?

"Children who lose their housing may have their lives disrupted for a long time, as they live in temporary or other housing" first author Yusuke Matsuyama says. "That may differ from witnessing a life-threatening event, which is traumatic but children may recover after they go through a grieving period."

After having experienced a disaster, there may be prolonged periods of recovery and instability. Being without housing in this period may induce stress or sadness, which may lead to impatience. The TMDU study offers specific insight into the emotions of children who survive this trauma.

A Delphi survey carried out by Dr Lyn Robinson, Head of Department and Reader in Library and Information Science at City, University of London, and Dr David Haynes, former Visiting Lecturer and Post-Doctoral Fellow in City's Department of Library and Information Science, has revealed priorities for protecting personal privacy online.

Their research study, "Delphi study of risk to individuals who disclose personal information online", published in the Journal of Information Science, was conducted at City in 2019, and is based on the views of a panel of privacy and information security experts.

A literature review, published between 2014 and 2019 provided a corpus of 69 research articles from peer-reviewed journals covering recent research into information privacy risk.

The articles were categorized using a cluster analysis based on Pearson's correlation coefficient to identify the main research themes.

Statements extracted from the articles were tested by questions put to an expert panel to identify future research priorities, grouped under the headings of Personalisation (Do intelligent user interfaces need to acquire rich information about users in order to be effective? How intrusive are personal ads and does that intrusiveness outweigh the benefits?); Social networks (How much information about individuals is revealed by the online activity of their associates such as connections on social media? Is there a way of detecting whether information about an individual revealed by a social media connection is misleading or incorrect?); Risk assessment (What is the relationship between connectedness and risk of online harm?) and Regulation; (Who should primarily be responsible for maintaining the privacy of social media users - the individual or the service provider? What are users' attitudes to different modes of privacy regulation - based on Lessig's model?)

The expert panel was also asked about their own attitudes to privacy harm and ranked financial loss and cyberbullying as the top two issues. They ranked online stalking, advertising intrusion and filtering of content as mid-ranking issues. These also feed into a view of the priorities for further research into online privacy.

The Delphi survey is a useful tool for identifying priority areas for further investigation extracted from a much longer list of research topics.

Tsukuba, Japan - Animals must make predictions about future rewards when making decisions during daily life. Specific reward-related patterns of neuronal activity are known to underlie such decisions. But now, researchers from Japan have found a new pattern of neural activity that occurs when responding to rewards that are changing over time.

In a study published this month in eLife, researchers from the University of Tsukuba have revealed that dopamine neurons, which process information about rewards, are activated in a previously undetected way when an animal considers a reward that is changing in value.

Previous studies have highlighted the importance of a specific pattern of activity in dopamine neurons, called phasic firing, in processing reward information. Such information has important implications for understanding how organisms successfully regulate reward-seeking behavior. However, this type of activity may not explain all types of rewards--for instance, those that change on a moment-to-moment basis, such as when a customer watches as a bartender pours their drink. The researchers at the University of Tsukuba aimed to investigate this possibility.

"Midbrain dopamine neurons are thought to respond to rewards and reward-predicting cues with phasic activity," says first author of the study Yawei Wang. "However, it seems unlikely that phasic dopamine activity, which is sporadic and has a short duration, can explain continuous monitoring of a shifting reward."

To address this, the researchers trained macaque monkeys to complete a Pavlovian task in which they made judgments about rewards that gradually increased or decreased. While the monkeys completed the task, the researchers recorded the activity in dopamine neurons that process information about the rewards.

"The results were surprising," explains Professor Masayuki Matsumoto, senior author. "Instead of phasic activity, the dopamine neurons fired in a tonic pattern that varied according to the moment-to-moment changes in the reward values."

This tonic firing pattern, which was a more sustained neuronal response compared with phasic firing, was caused by a different type of neuronal activation than that associated with phasic dopamine neuron activity during reward processing.

"Our findings add to the current understanding of how dopamine neurons are involved in rewards by highlighting the existence of multiple neuronal firing modes that signal reward values in specific situations," says Yawei Wang.

Given that dopamine is a powerful neurotransmitter involved in many brain functions, understanding how dopamine neurons process and transmit information is critical to understanding the mechanisms of cognition. This research opens the door to new investigations of the role of the tonic activity of dopamine neurons in reward processing.

Optical tweezers and associated manipulation tools in the far field have had a major impact on scientific and engineering research by offering precise manipulation of small objects. More recently, the near-field manipulation with surface plasmons has opened opportunities not feasible with conventional far-field optical methods. The use of surface plasmon techniques enables excitation of hotspots much smaller than the free-space wavelength; with this confinement, the plasmonic field facilitates trapping of various nanostructures and materials with higher precision. It has become commonly used in trapping of micro- and nanometre-sized objects in various fields of science.

In a new review paper published in Light Science & Application, a team of scientists, led by Professor Xiaocong Yuan from Nanophotonics Research Center, Shenzhen University, China, and co-workers have reviewed the principles, developments, and applications of the plasmonic tweezers techniques, including both nanostructure-assisted platforms and structureless systems.

According to excitation situations, surface plasmon can be divided into two types: localized surface plasmon in bounded geometries such as nanoparticles and all-optical excited structureless surface plasmon polaritons on a smooth dielectric-metal interface. Accordingly, the plasmonic tweezers system can be divided into structural type and all-optical modulated type. The structural platform provides an effective approach to trap micro- and nano-scale objects with the advantages of high precision; while the all-optical modulated type is an effective complement for dynamic manipulation and expand the trapping size range to mesoscopic and Mie range. These two kinds of plasmonic tweezers complement each other and have fostered numerous and expanding applications.

Owing to great strides in fundamental science, plasmonic tweezers have been used to manipulate many kinds of matter with various shapes, properties, and compositions. By feat of this technique, small objects can be manipulated dynamically to be sorted and transported for on-chip lithography and fabrications. In particular, biological particles of all sizes are important targets for trapping, and the plasmonic platforms exactly provide stable noninvasive probes for manipulation and detection of them.

Moreover, plasmonic hotspots can be selectively generated as specific traps through the design of structures or modulation of the polarization and phase distribution of excitation laser beams. Such hotspots have the advantages of strong near-field energy, providing the possibility of enhancing spectroscopic measurement of molecules located in the region through techniques such as SERS, infrared absorption, and fluorescence emission spectroscopy. The nanoscale precision of the method enables manipulation and detection at the molecular level, making plasmonic tweezers an important tool for physics, chemists, and life scientists.

"The mechanism and relevant phenomena in nonlinear light-matter interactions, and the intracellular manipulation and detection applications will be the possible development directions and breaking points of the plasmonic tweezers technique in the future." the scientists forecast.

"There are still challenges to be overcome in terms of the inherent properties to extend the applicability of the technique. Regardless, we are confident that the uses of plasmonic tweezer techniques will continue to grow in the near future, and many new applications in this area will be developed. " they added.

Laser ignition (LI) is a promising electrode-less alternative to electronic spark ignition of lean fuel/air mixtures, offering high thermal efficiency with low harmful emissions. One of the most widely adopted LI methods is nanosecond laser-induced spark ignition (ns-LISI), in which combustible mixtures undergo multiphoton ionization followed by avalanche breakdown, resulting in high-temperature and high-pressure plasma along with shockwaves. However, inevitable shot-to-shot energy fluctuations resulting from ns light sources lead to the stochastic nature of the breakdown, influencing reaction routes and producing potential misfiring.

Although LI is not a new concept, it is commonly deemed that igniting lean-fuel mixtures by an ultrashort femtosecond (fs) laser is hard to realize since avalanche breakdown cannot occur on the fs timescale, and the fs-laser-induced plasma temperature is 1-2 orders of magnitude smaller than that pumped by ns lasers, both of which decrease the lean-fuel ignitability. Indeed, researchers have failed so far to ignite lean mixtures using intense fs-pulsed lasers.

In a new paper published in Light Science & Application, a team of scientists, led by Professor Huailiang Xu from State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, China, and Professor Ruxin Li from State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, have demonstrated the successful realization and robustness of fs-LI by irradiating a lean methane/air mixture with an intense fs laser pulse in the filamentation regime. It is revealed that the pump laser energy for lean combustion can decrease to ?1.5 mJ with an energy deposition of ?25%, implying that it takes only sub-mJ energy to achieve fs-LI. They tested the laser ignition with a 1.8-mJ laser energy more than 1000 times and consequently achieved a 100% rate of success, showing the robustness of this approach for igniting lean mixtures. The present approach has general applicability to the complex combustion conditions in a variety of engines that are not in stoichiometric ratios.

It is shown that the fs-LI scheme has two major advantages compared with the ns-LISI scheme: (i) ultralow ignition energy, which is about one order of the magnitude smaller than that in ns-LISI scheme, and (ii) 100% ignition success rate. The fs-LI mechanism is ascribed to the thermal effect by laser energy deposition in the filament followed by combustion chemical reactions and the robustness to the line ignition effect, which is described in detail as below:

"The dynamic equilibrium between self-focusing and plasma defocusing in the laser filament allows for the generation of several Rayleigh-range or longer plasma channels with the laser intensity clamped at the ?50-100 TW/cm2 level. Fuel molecules can be activated and even fragmented by high-intensity laser filaments, producing many combustion intermediates. In particular, the long filament provides the possibility of "multipoint" ignition along the filament, referred to as "line" ignition, which can help improve the ignition reliability of lean mixtures."

"In addition, inside the fs laser filament, although the initial temperature of gas molecules determined through various energy deposition pathways, such as multiphoton/tunnel ionization, dissociation, Raman excitation, and collision excitation is only approximately 1400 K, the low-temperature oxidation reaction of methane molecules can still occur, which allows for the initiation of combustible chemical reactions" they added.

"The present approach, in which the ultrashort laser ignition of lean-fuel mixtures works in a relatively low-temperature and centimeter-long plasma filament, not only has general applicability to complex combustion conditions in a variety of engines that are not in stoichiometric ratios, but provides possibilities for investigating ultrafast physical/chemical processes on the fs/ps timescale after the laser-fuel interaction" the Scientists forcast.

Artificial light at night (ALAN) is a major factor in global insect decline. In a paper published today in Insect Conservation and Diversity, Smithsonian Conservation Biology Institute (SCBI) scientists and partners found that using amber-colored filters to remove the blue spectra of light from "warm white" LED (light-emitting diode) lamps drastically reduces insect attraction to nocturnal lighting in a tropical forest. This is the first study to validate quantitative predictions of how lamp color affects insect attraction and provide clear recommendations to mitigate the negative impacts of ALAN on wildlife in rainforest ecosystems.

"While many people aren't necessarily fond of 'bugs,' their importance in our everyday lives is indisputable," said Jessica Deichmann, first author and research scientist with the Smithsonian Conservation Biology Institute and the Smithsonian Conservation Commons' Working Land and Seascapes Initiative. "The essential ecosystem services they provide are endangered by nighttime lighting. We shouldn't abandon using LED lights--their energy efficiency is second to none. Our research presents an alternative, especially for outdoor settings. If people everywhere take small steps in our homes, neighborhoods and commercial properties, we can reduce the negative impacts of sustainable LED lighting on wildlife."

In addition to using filtered LEDs that remove the blue light and appear more orange/amber in color, additional ways to support insects include the use of full cutoff fixtures, motion activators and dimmers to ensure light is used only when and where it is needed.

Insects play invaluable roles as pollinators of food plants, regulators of other insect pests, decomposers of waste and sources of food for other animals, like birds. Insects may be directly affected by lights when they suffer mortality from collisions with hot lamps, exhaustion or increased predation due to the attraction of predators and/or increased visibility. Insects affected by artificial lighting may also become disoriented or inactive, leading to a failure to reproduce, and consequently, a reduction of gene flow in the population.

The study was conducted in lowland rainforest in northern Peru inside a hydrocarbon (oil and gas) concession currently operated by GeoPark Peru. Scientists set light traps in 12 different locations with three different LED lamps with different spectra and a control (no light) to evaluate the number and composition of insects attracted to lamps during two different time periods at night.

Researchers identified 763 unique morphospecies among the greater than 15,000 insects captured across all samples, belonging to 18 different orders. Overall, significantly more morphospecies were captured in the white LED light traps than in either the yellow or amber-filtered traps or the control. Likewise, significantly more individual insects were captured in the white LED traps.

By using amber-filtered LEDs, the number of morphospecies attracted to the light was reduced by 34% and individual insects were reduced by nearly 60% as compared to white LED lamps with reduced blue-light content. In addition, among captured insect families known to contain important vectors of pathogens, bacteria or parasites, 45% of all individuals were captured at white lamps, 41% at yellow lamps and just 13% were found in amber lamp traps.

These results provide essential, tangible and actionable information on how to minimize ALAN, an unavoidable consequence of many types of infrastructure development and urbanization. The paper lays out specific management recommendations for new infrastructure projects in tropical forests that can also be applied to urban and rural residential areas.

BOSTON - There are several effective interventions to reduce the risk of suicide, the tenth-leading cause of death in the United States, but difficulties in identifying people at risk for suicide and concerns about the potentially high costs of suicide-prevention strategies have hampered their wider use.

But as researchers at Massachusetts General Hospital (MGH) demonstrate, statistical suicide risk prevention models could be implemented cost-effectively in U.S. health care systems and might help save many lives each year.

By evaluating data on the incidence of suicide and suicide attempts, the costs to society and the health care system of suicide, and the cost and effectiveness of suicide risk-reduction interventions, Eric L. Ross, MD, a resident in the Department of Psychiatry at MGH and colleagues found that several existing suicide risk prediction models are sufficiently accurate at identifying at-risk individuals to allow cost-effective implementation in clinical practice.

They report their findings in the journal JAMA Psychiatry.

"There are complex statistical models that researchers have come up with to predict who is at the highest risk of suicide or suicide attempts, and our analysis suggests that those models are now accurate enough that we could be implementing them in the real world," says Ross.

"And if we do implement them, our analysis suggests they would be cost effective. That doesn't suggest that it would save the health care system money, but it does mean it would be a good investment of resources in order to improve people's quality of life and improve people's longevity," he adds.

Ross and colleagues created a mathematical model projecting suicide-related health economic outcomes over a lifetime for U.S. adults treated by primary care physicians. The model looked at the practicality of predicting individuals' risk of suicide and then offering either of two possible interventions for people at high risk: active contact and follow-up, in which the patient at risk receives an initial intensive evaluation, and is contacted frequently thereafter by telephone or mail; and cognitive behavioral therapy, a form of psychotherapy in which the therapist helps the patient identify and change self-destructive or disturbing thought patterns.

Using standard health economics measures, the researchers found that both interventions could be cost-effective as long the models used to predict suicide risk were accurate enough. When they examined prediction models developed by previous researchers, they found that several of these models would be accurate enough to be practical and cost-effective.

"[The results] suggest that current risk prediction models have achieved sufficient accuracy for health systems to move forward with pilot implementation projects," Ross and colleagues write in the paper's conclusion.

According to senior author Jordan W. Smoller, MD, ScD, of the Department of Psychiatry at MGH, "suicide rates have increased substantially over the past 20 years, so it is clear that we need new tools for addressing this national problem. Most individuals who die by suicide are seen by health care providers in the months before their death, so health care settings have a crucial opportunity to prevent this tragedy. Our results suggest that the tools exist to enable cost-effective interventions. And that, I think, is cause for hope."

Combining tissue engineering and regenerative medicine, scientists have fabricated a series of heart valve replacements with the ability to incorporate host cells, enabling them to regenerate and grow over time. The valves expanded and maintained their function for a year when implanted into growing lambs, suggesting they could address the dire need for a long-term valve replacement for children with congenital heart disorders. These pediatric patients depend on mechanical or prosthetic heart valves for survival, but current devices often calcify over time and cannot grow alongside the child's heart. As a result, these patients routinely undergo as many as five open heart surgeries to have their valves repeatedly replaced until they reach adulthood. These procedures carry significant risks and healthcare costs, and pediatric patients must continue to take lifelong anticoagulation therapy. Building on their previous work, Zeeshan Syedain and colleagues manufactured a pediatric valve replacement that adapts to the growing heart and can host layers of cells. Using tissue engineering, the authors based their valve replacement on three tubes of decellularized extracellular matrix, which can become populated with cells after implantation. The first generation of tri-tube valves increased in diameter over a span of 52 weeks after being implanted into four lambs, but exhibited some blood regurgitation and degraded valve function over time. Syedain et al. then devised a second-generation design that includes an additional tube sleeve, which improved growth dynamics and mitigated blood pressure drops in two lambs in a second group of animals. Importantly, the valves also showed fewer signs of damaging calcification than clinically used bioprosthetic valves in the lambs. The scientists call for studies with larger cohorts to better assess the long-term potential of both tri-tube valve designs.

ITHACA, N.Y. - If you want to build a fully functional nanosized robot, you need to incorporate a host of capabilities, from complicated electronic circuits and photovoltaics to sensors and antennas.

But just as importantly, if you want your robot to move, you need it to be able to bend.

Cornell researchers have created micron-sized shape memory actuators that enable atomically thin two-dimensional materials to fold themselves into 3D configurations. All they require is a quick jolt of voltage. And once the material is bent, it holds its shape - even after the voltage is removed.

As a demonstration, the team created what is potentially the world's smallest self-folding origami bird. And it's not a lark.

The group's paper, "Micrometer-sized electrically programmable shape memory actuators for low-power microrobotics," published in Science Robotics and was featured on the cover. The paper's lead author is postdoctoral researcher Qingkun Liu.

The project is led by Itai Cohen, professor of physics, and Paul McEuen, the John A. Newman Professor of Physical Science.

McEuen and Cohen's ongoing collaboration has so far generated a throng of nanoscale machines and components, each seemingly faster, smarter and more elegant than the last.

"We want to have robots that are microscopic but have brains on board. So that means you need to have appendages that are driven by complementary metal-oxide-semiconductor (CMOS) transistors, basically a computer chip on a robot that's 100 microns on a side," Cohen said.

Imagine a million fabricated microscopic robots releasing from a wafer that fold themselves into shape, crawl free, and go about their tasks, even assembling into more complicated structures. That's the vision.

"The hard part is making the materials that respond to the CMOS circuits," Cohen said. "And this is what Qingkun and his colleagues have done with this shape memory actuator that you can drive with voltage and make it hold a bent shape."

The machines fold themselves fast, within 100 milliseconds. They can also flatten and refold themselves thousands of times. And they only need a single volt to be powered to life.

The team has already been recognized by Guinness World Records for creating the smallest walking robot. Now, they hope to capture another record with a new self-folding origami bird that is only 60 microns wide.

The team is currently working to integrate their shape memory actuators with circuits to make walking robots with foldable legs as well as sheet-like robots that move by undulating forward. These innovations may someday lead to nano-Roomba-type robots that can clean bacterial infection from human tissue, micro-factories that can transform manufacturing, and robotic surgical instruments that are ten times smaller than current devices, according to Cohen.

Many people have never heard of Brucellosis, but farmers and ranchers in the United States forced to cull animals that test positive for the disease and people infected by the animal-transmitted Brucella abortus (B. abortus) pathogen that suffer chronic, Malaria-type symptoms, certainly have.

Brucellosis is an agricultural and human health concern on a global scale. It was introduced over 100 years ago to Bison and elk in Yellowstone National Park by cattle and has been circulating among the wild herds ever since, leading to periodic outbreaks and reinfection. There is no vaccine for humans, and experimental studies of B. abortus in its natural animal hosts are technically difficult, extremely expensive and only a few facilities are capable of conducting these studies.

That did not stop Sean Crosson, MSU Rudolph Hugh Endowed Professor, and colleague Aretha Fiebig, research associate professor in Michigan State University's Department of Microbiology and Molecular Genetics, from bringing sophisticated genomics tools from the lab to the field to gain new insight into how B. abortus infects cattle and help stop the spread of this deadly disease.

The results of their study were published in the Proceedings of the National Academy of Sciences.

"B. abortus primarily infects cattle, causing pregnant cows to abort the fetus, but the infection is typically studied in mouse models, which are not the true host of the bacterium," explained Crosson, who has been studying the bacteria for more than 14 years. "If you want to understand the infection biology underlying bovine disease, then it's helpful to study things in the natural host in a field context."

In the microbiological equivalent to tagging cattle, Crosson and Fiebig harnessed the hopping ability of specialized DNA called transposons to tag individual strains of B. abortus with unique barcodes. This gave them the ability to count how many B. abortus bacteria made it from the cow's eye, a common point of infection in the field, to the lymph nodes.

"As molecular biologists, we can harness hopping DNA by separating away the enzyme that allows it to continue moving," said Fiebig, who specializes in bacterial regulatory mechanisms. "We temporarily gave DNA the ability to hop into the B. abortus genome, but it didn't hop out again."

The scientists mixed millions of E. coli bacteria carrying transposons with millions of B. abortus in a broth containing amino acids and sugars, initiating mass tagging through a process called bacterial conjugation where transposons hop into and unite with the B. abortus genome. When the remaining E. coli cells were washed away, they were left with a vat of individually barcoded B. abortus strains.

"We were able to make a rich pool of about a million different barcoded strains," Fiebig said. "When we infected the cattle, we could track almost every single strain and ask, 'how many strains got lost, what strains had an advantage and was that advantage for a genetic reason or just chance?'"

Millions of bacteria went in, but surprisingly few came out. And while the genetic identity of strains that made it through was random, the number of strains that managed to infect individual lymph nodes was remarkably similar.

"We knew there was some restriction, or infection bottleneck, but we didn't understand the magnitude until this study," said Fiebig.

The unexpected results required nontraditional computational analysis, so Marianne Huebner, director of MSU's Center for Statistical Training and Consulting, provided expert guidance on the use of mathematical models to assess the population structures of the bacteria that survived the bottleneck.

Infecting a large animal host with a federally regulated pathogen also presented significant methodological challenges. The researchers relied on the highly skilled veterinarians and high-tech facilities at the United States Department of Agriculture-Agricultural Research Service's (USDA-ARS) National Animal Disease Center in Ames, Iowa where the cows in the study were housed and treated.

The challenging field study paid off, providing critical insight into just how good the cow's mucosal barrier is at restricting B. abortus during infection.

"In the end, we gained a quantitative understanding of an infection bottleneck via a common route of bovine infection in the field," Crosson said. "This information is useful for scientists studying the epidemiology of Brucellosis in livestock and wildlife and can help us build better transmission models as we work to stop the spread of this disease."

The proof of principle paper also opened new doors to discovering specific B. abortus genes involved in the devastating disease.

"Going forward, we better understand how to use our library of barcoded mutants over longer timepoints in a pregnant host to find B. abortus genes that influence the most severe outcomes in cattle, including abortion," Crosson said. "This is a goal of the USDA-ARS as well, to know what genes in B. abortus are critical to infection in the bovine host."