Tech

PITTSBURGH, July 21, 2020 - Imagine tying your shoes or taking a sip of coffee or cracking an egg but without any feeling in your hand. That's life for users of even the most advanced prosthetic arms.

Although it's possible to simulate touch by stimulating the remaining nerves in the stump after an amputation, such a surgery is highly complex and individualized. But according to a new study from the University of Pittsburgh's Rehab Neural Engineering Labs, spinal cord stimulators commonly used to relieve chronic pain could provide a straightforward and universal method for adding sensory feedback to a prosthetic arm.

For this study, published today in eLife, four amputees received spinal stimulators, which, when turned on, create the illusion of sensations in the missing arm.

"What's unique about this work is that we're using devices that are already implanted in 50,000 people a year for pain -- physicians in every major medical center across the country know how to do these surgical procedures -- and we get similar results to highly specialized devices and procedures," said study senior author Lee Fisher, Ph.D., assistant professor of physical medicine and rehabilitation, University of Pittsburgh School of Medicine.

The strings of implanted spinal electrodes, which Fisher describes as about the size and shape of "fat spaghetti noodles," run along the spinal cord, where they sit slightly to one side, atop the same nerve roots that would normally transmit sensations from the arm. Since it's a spinal cord implant, even a person with a shoulder-level amputation can use this device.

Fisher's team sent electrical pulses through different spots in the implanted electrodes, one at a time, while participants used a tablet to report what they were feeling and where.

All the participants experienced sensations somewhere on their missing arm or hand, and they indicated the extent of the area affected by drawing on a blank human form. Three participants reported feelings localized to a single finger or part of the palm.

"I was pretty surprised at how small the area of these sensations were that people were reporting," Fisher said. "That's important because we want to generate sensations only where the prosthetic limb is making contact with objects."

When asked to describe not just where but how the stimulation felt, all four participants reported feeling natural sensations, such as touch and pressure, though these feelings often were mixed with decidedly artificial sensations, such as tingling, buzzing or prickling.

Although some degree of electrode migration is inevitable in the first few days after the leads are implanted, Fisher's team found that the electrodes, and the sensations they generated, mostly stayed put across the month-long duration of the experiment. That's important for the ultimate goal of creating a prosthetic arm that provides sensory feedback to the user.

"Stability of these devices is really critical," Fisher said. "If the electrodes are moving around, that's going to change what a person feels when we stimulate."

The next big challenges are to design spinal stimulators that can be fully implanted rather than connecting to a stimulator outside the body and to demonstrate that the sensory feedback can help to improve the control of a prosthetic hand during functional tasks like tying shoes or holding an egg without accidentally crushing it. Shrinking the size of the contacts -- the parts of the electrode where current comes out -- is another priority. That might allow users to experience even more localized sensations.

"Our goal here wasn't to develop the final device that someone would use permanently," Fisher said. "Mostly we wanted to demonstrate the possibility that something like this could work."

People who have periodontal (gum) disease may have a higher risk of developing some forms of cancer, suggests a letter published in the journal Gut detailing a prospective study.

US researchers found that a history of periodontal disease appeared to be associated with a raised risk of oesophageal (gullet) cancer and gastric (stomach) cancer and this risk was also higher among people who had lost teeth previously.

Previous findings on the relationship of periodontal disease and tooth loss with oesophageal and gastric cancer have been inconsistent.

Therefore, a team of researchers from Harvard T.H. Chan School of Public Health, in Boston, USA, carried out a study of data on patients over decades of follow up.

They examined the association of history of periodontal disease and tooth loss with the risk of oesophageal and gastric cancer in 98,459 women from the Nurses' Health Study (1992-2014) and 49,685 men from the Health Professionals Follow-up Study (1988-2016).

Dental measures, demographics, lifestyle, and diet were assessed using follow-up questionnaires and self-reported cancer diagnosis was confirmed after reviewing medical records.

The results showed that during 22-28 years of follow-up, there were 199 cases of oesophageal cancer and 238 cases of gastric cancer.

A history of periodontal disease was associated with a 43% and 52% increased risk of oesophageal cancer and gastric cancer, respectively.

Compared to people with no tooth loss, the risks of oesophageal and gastric cancer for those who lost two or more teeth were also modestly higher - 42% and 33%, respectively.

In addition, among individuals with a history of periodontal disease, no tooth loss and losing one or more teeth were equally associated with a 59% increased risk of oesophageal cancer compared to those with no history of periodontal disease and no tooth loss.

Similarly, the same group of individuals had 50% and 68% greater risk of gastric cancer, respectively.

The authors point to possible reasons for an association between oral bacteria (oral microbiota) and oesophageal and gastric cancer, with evidence from other studies suggesting that tannerella forsythia and porphyromonas gingivalis - members of the 'red complex' of periodontal pathogens - were associated with the presence or risk of oesophageal cancer.

Another possible reason is that poor oral hygiene and periodontal disease could promote the formation of endogenous nitrosamines known to cause gastric cancer through nitrate-reducing bacteria.

This was an observational study, so no firm conclusions can be drawn about cause and effect, and the researchers cannot rule out the possibility that some of the observed risk may be due to other unmeasured (confounding) factors.

However, they conclude: "Together, these data support the importance of oral microbiome in oesophageal and gastric cancer. Further prospective studies that directly assess oral microbiome are warranted to identify specific oral bacteria responsible for this relationship. The additional findings may serve as readily accessible, non-invasive biomarkers and help identify individuals at high risk for these cancers."

DUARTE, Calif. -- For people with diabetes, vascular complications like kidney disease and atherosclerosis, which can lead to poor health and even death, are seen at increased rates. In a new Nature Metabolism study, researchers led by City of Hope's Rama Natarajan, Ph.D., the National Business Products Industry Professor in Diabetes Research, identified for the first time an underlying mechanism for metabolic memory and its involvement in the development of such complications.

Prior episodes of poor glycemic control can result in long-term sustained complications for people with diabetes even if they are able to institute good glycemic control later on in life. This phenomenon is called metabolic memory, but the way it works is not well understood.

"While the link between epigenetics and diabetes and related complications has been reported before, this is the first large scale study in type 1 diabetes showing that a prior history of high glucose levels can cause persistent changes in DNA methylation to facilitate metabolic memory and trigger future diabetic complications," said Natarajan, the study's senior author, who is also professor and chair of the Department of Diabetes Complications & Metabolism within the Diabetes & Metabolism Research Institute at City of Hope. "This study provides the first evidence in humans supporting the link between DNA methylation in inflammatory and stem cells, a patient's blood sugar history and development of future complications."

Natarajan and her colleagues collaborated with the landmark Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) clinical trial of type 1 diabetic patients to examine the role of epigenetics in metabolic memory. Epigenetics refers to heritable changes in gene expression and phenotypes that occur without changes in the person's genetic code. Epigenetic changes occur on chromatin which holds our DNA together in the nucleus and, in general, these alterations are induced by changes in lifestyles and the environment.

The researchers led by Zhuo (Nancy) Chen, who is the study's lead author and a staff scientist in Natarajan's lab, profiled DNA methylation, a type of epigenetic modification, in archived blood DNA samples from 500 participants enrolled in the DCCT/EDIC. They then compared the DNA methylation to their glycemic history and future development of complications. The team found that a prior history of hyperglycemia may induce persistent DNA methylation changes in blood cells and stem cells at key loci, which are epigenetically retained in certain cells to facilitate metabolic memory, likely through modifying enhancer activity at nearby genes.

This comprehensive study has systematically compared the epigenetic states of a large number of type 1 diabetic subjects with their glycemic history and their future development of key diabetic complications over 18 years, Natarajan said. Although epigenetic mechanisms have been implicated in diabetic complications before using experimental models or epigenome-wide association studies, the direct mediation role of DNA methylation in metabolic memory and future complications development had not been systematically studied.

Natarajan says that the study results could lead to the development of epigenetic marks as potential biomarkers for diabetic complication development and metabolic memory, which would help facilitate early intervention and prevent the progression to severe complications. In addition, the data can provide new insights into the mechanisms of metabolic memory related to the specific regions and genes affected by DNA methylation and these genes could also be potential drug targets. In fact, Natarajan is actively collaborating with Nagarajan Vaidehi, Ph.D., chair of the Department of Computational and Quantitative Medicine at City of Hope, and her group to use novel computational screening methods to identify small molecule inhibitors targeting molecules identified in the current study to aid in the treatment of complications and metabolic memory.

Several other follow-up studies are under way in Natarajan's laboratory, including collaborations with scientists both inside and outside of City of Hope. In the current study, she and her team performed associations between DNA methylation and two major diabetic complications: retinopathy, which can lead to blindness, and nephropathy, which can lead to kidney failure requiring dialysis or transplantation. Chen and Natarajan now plan to study associations with other long-term complications of type 1 diabetes, and also evaluate DNA methylation as a biomarker for predicting complications development.

"In addition, our team is expanding our study on the same group of patients as the Nature Metabolism research using whole-genome bisulfite sequencing to examine epigenetic changes over the whole genome," Natarajan said. "The goal is to uncover additional regions where DNA methylation is associated with metabolic memory or complication development besides those uncovered in the current paper."

Natarajan and her team are also continuing to collaborate with two co-authors of the Nature Metabolism paper, Arthur D. Riggs, Ph.D., the Samuel Rahbar Chair in Diabetes & Drug Discovery and director of the Diabetes & Metabolism Research Institute at City of Hope, and Joshua Tompkins, Ph.D., assistant research professor in the Department of Diabetes Complications & Metabolism, to examine DNA methylation at the single molecule level, and also evaluate epigenetic engineering approaches to reverse metabolic memory.

Dr Duncan Hodges, Senior Lecturer in Cyberspace Operations, Cranfield University, is actively researching insider threats such as the recent Twitter attacck . He and researcher Katie Paxton-Fear are presenting this paper Understanding Insider Threat Attacks Using Natural Language Processing, at the HCI International Conference on Thursday 23 July 1400CEST. 

"The Twitter attack did not target individuals but the platform itself, and exploited a tool internal to the company.  The 'attack' originated from internal actors and was a 'malicious insider threat' - where those with legitimate access use it for malicious activity.  Evidence suggests the internal actor was simply bribed to use the tool they had access to. 

"Insider threats are very difficult to detect and many companies use tools to try and monitor their systems and employees.  However, these tools give degrees of access which can be a significant risk, from an insider threat perspective. 

"Our latest research considers how reports and viewpoints from employees can be automatically mapped onto an understanding of insider threat. This increased level of knowledge can help organisations better manage security risks originating from insider attacks." 

EAST LANSING, Mich. - Need a robot with a soft touch? A team of Michigan State University engineers has designed and developed a novel humanoid hand that may be able to help.

In industrial settings, robots often are used for tasks that require repetitive grasping and manipulation of objects. The end of a robot where a human hand would be found is known as an end effector or gripper.

"The novel humanoid hand design is a soft-hard hybrid flexible gripper. It can generate larger grasping force than a traditional pure soft hand, and simultaneously be more stable for accurate manipulation than other counterparts used for heavier objects," said lead author Changyong Cao, director of the Laboratory for Soft Machines and Electronics at MSU and assistant professor in Packaging, Mechanical Engineering, and Electrical and Computer Engineering.

This new research, "Soft Humanoid Hands with Large Grasping Force Enabled by Flexible Hybrid Pneumatic Actuators," is published in Soft Robotics.

Generally, soft-hand grippers -- which are used primarily in settings where an object may be fragile, light and irregularly shaped -- present several disadvantages: sharp surfaces, poor stability in grasping unbalanced loads and relatively weak grasping force for handling heavy loads.

When designing the new model, Cao and his team took into consideration a number of human-environment interactions, from fruit picking to sensitive medical care. They identified that some processes require a safe but firm interaction with fragile objects; most existing gripping systems are not suitable for these purposes.

The team explained that the design novelty resulted in a prototype demonstrating the merits of a responsive, fast, lightweight gripper capable of handling a multitude of tasks that traditionally required different types of gripping systems.

Each finger of the soft humanoid hand is constructed from a flexible hybrid pneumatic actuator -- or FHPA -- driven to bend by pressurized air, creating a modular framework for movement in which each digit moves independently of the others.

"Traditional rigid grippers for industrial applications are generally made of simple but re-
liable rigid structures that help in generating large forces, high accuracy and repeatability," Cao said. "The proposed soft humanoid hand has demonstrated excellent adaptability and compatibility in grasping complex-shaped and fragile objects while simultaneously maintaining a high level of stiffness for exerting strong clamping forces to lift heavy loads."

In essence, the best of both worlds, Cao explained.

The FHPA is composed of both hard and soft components, built around a unique structural combination of actuated air bladders and a bone-like spring core.

"They combine the advantages of the deformability, adaptability and compliance of soft grippers while maintaining the large output force originated from the rigidity of the actuator," Cao said.

He believes the prototype can be useful in industries such as fruit picking, automated packaging, medical care, rehabilitation and surgical robotics.

With ample room for future research and development, the team hopes to combine its advances with Cao's recent work on so-called 'smart' grippers, integrating printed sensors in the gripping material. And by combining the hybrid gripper with 'soft arms' models, the researchers aim to more accurately mimic precise human actions.

Bioinformatics and big data analyses can reap great rewards for biologists, but it takes a lot of work to generate the datasets necessary to begin. At the same time, researchers around the globe churn out datasets that could be useful to others but are not always widely shared.

To foster scientific exchange and to advance discovery, biologists in the School of Arts & Sciences led by postdoc Stefan Schulze and professor Mecky Pohlschroder have launched the Archaeal Proteome Project (ArcPP), a web-based database to collect and make available datasets to further the work of all scientists interested in archaea, a domain of life composed of microorganisms that can dwell anywhere from deep-sea vents to the human gut.

"This is a very community-focused effort," says Schulze, who has worked as a postdoc in Pohlschroder's lab since 2017 and took the lead in developing the ArcPP platform, which is described in a recent Nature Communications paper. "People who are working in different fields and are interested in different biological questions may all be generating proteomics datasets to answer their questions. But those same datasets could be analyzed to answer other questions as well. Our idea was to bring these datasets together in a uniform way to be of use to the whole community."

Pohlschroder's lab studies the archaeon Haloferax volcanii as a model organism, a salt-loving species originally isolated from the Dead Sea. While the ArcPP launched with data from only this species, the researchers hope to rapidly grow it to encompass proteomic data--a cataloging of the entire set of proteins contained in an organism--from more archaeal species and even beyond, including other single-celled organisms, such as bacteria.

"The principle of the ArcPP can be seen as similar to the collaboration between medical specialists treating a patient," Schulze says. "Brain, heart, or kidney specialists all have expert knowledge in their respective fields, but for all of them a blood sample can help to interpret symptoms of a patient. Similar to that blood sample, modern proteomics, which can analyze the whole proteomes of an organism within a single experiment, provide information about various aspects of archaeal cell biology."

Archaea are a relatively understudied group, but they play important ecological roles, are used for various biotechnological applications, and appear to be the prokaryotic ancestors of eukaryotes. Thus, the field is ripe for novel insights into their biochemistry and function.

Recent advances have made it much simpler to generate the raw data needed to perform proteomics studies with an organism. "Now the bottleneck is how do you effectively analyze it, and what do you make out of this analysis," Pohlschroder says.

That's where the ArcPP community comes in. "I might understand why certain proteins are expressed or modified on the cell surface because that's what we focus on in our lab," she says, "but our colleagues study other aspects of archaeal biology. By bringing together the community of scientists studying various aspects of archaeal proteomics, ArcPP can provide the research community with an abundance of easily accessible data and also has the expertise and perspectives needed to analyze the data in ways that will yield significant new insights into archaeal biology."

To develop the ArcPP, the Penn biologists reached out to multiple laboratories around the world to contribute their proteomics datasets for H. volcanii. The data represented analyses of the microbes growing in a broad range of conditions, resulting in a collection that is a massive two terabytes in size.

"We were able to identify 72% of known proteins encoded in the H. volcanii proteome," Pohlschroder says. "By comparing different culture conditions, we were able to identify proteins that are always present, indicating that they are crucial for cell functions in a variety of environments. Interestingly, for at least 15% of these proteins the function is as of yet completely unknown, highlighting that our understanding of archaeal cell biology is still quite limited."

Schulze put the platform to the test to see what new information could be gleaned. Together with other members of the group, he used the database to find that, contrary to what was previously believed about H. volcanii, it can express the enzyme urease, which breaks down the nitrogen compound urea, though only in the presence of glycerol as a carbon source. Follow-up experiments at the bench by collaborators from the University of Florida confirmed the finding, offering a proof-of-concept of the power of ArcPP.

"Expressing urease could be important in nitrogen cycling in the environment," Schulze says, "or even for biotechnology applications."

Another powerful aspect of ArcPP is its utility for education. Bioinformatics is an invaluable skill for up-and-coming biologists, and analyses that can be done at the computer rather than the lab are a useful way to safely continue scientific discovery amid the COVID-19 pandemic. It's something that even the high school students that Pohlschroder invites into her lab through the program Penn LENS, short for Laboratory Experience in Natural Sciences, can experience in a hands-on format.

"What I think is fascinating about this project is that you can work with Haloferax volcanii, which is non-pathogenic and fairly easy to work with," Pohlschroder says, "and pair it with cutting-edge technology but do it in such a way that high school students are capable of making absolutely novel discoveries. It's something we are definitely thinking about using for the upcoming semester for undergraduates as well since they may not be able to come into the laboratory right away."

A new study Schulze, Pohlschroder, doctoral student Heather Schiller, and colleagues,
released as a pre-print to bioRxiv, prior to peer-review, also offers hints at how ArcPP might play a role in extending bench-based scientific discoveries. Many archaea, like bacteria, can form biofilms, which are microbial communities of adherent cells embedded in an extracellular polymeric matrix. H. volcanii can form biofilms either on solid surfaces or in liquid media. Schulze had noticed that, when H. volcanii forms a biofilm in liquid media contained in a petri dish, it can rapidly develop an intricate honeycomb pattern upon the removal of the petri dish lid.

After some detective work to find out what is responsible for creating this formation, the researchers ruled out genes responsible for surface adhesion, light, oxygen, humidity, and other variables, and they now believe the driver to be a volatile compound in the air.

While the group is planning further "wet lab" follow-up to determine whether other archaeal species and even certain bacteria do something similar, they also hope to lean on the ArcPP to better understand the mechanism of the honeycomb formation, as the included datasets contain proteomic information from microbes in biofilms as well as growing freely.

"I always see bioinformatics and lab work as a circle," Schulze says. "You may start with lab work, go to bioinformatics to probe into a finding, but you don't stop there. You should always go back to the lab--and then back around--to confirm and extend your findings."

With ArcPP, these biologists are hoping to extend that circle, bringing more researchers--and young people with scientific aspirations--into the fold.

"We are eager to work together with more laboratories in order to extend our analyses to other archaeal species or even bacteria, harvesting the synergistic effects of a broad scientific community," says Pohlschroder.

HOUSTON - (July 20, 2020) - A shield of graphene helps particles destroy antibiotic-resistant bacteria and free-floating antibiotic resistance genes in wastewater treatment plants.

Think of the new strategy developed at Rice University as "wrap, trap and zap."

The labs of Rice environmental scientist Pedro Alvarez and Yalei Zhang, a professor of environmental engineering at Tongji University, Shanghai, introduced microspheres wrapped in graphene oxide in the Elsevier journal Water Research.

Alvarez and his partners in the Rice-based Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment (NEWT) have worked toward quenching antibiotic-resistant "superbugs" since first finding them in wastewater treatment plants in 2013.

"Superbugs are known to breed in wastewater treatment plants and release extracellular antibiotic resistance genes (ARGs) when they are killed as the effluent is disinfected," Alvarez said. "These ARGs are then discharged and may transform indigenous bacteria in the receiving environment, which become resistome reservoirs.

"Our innovation would minimize the discharge of extracellular ARGs, and thus mitigate dissemination of antibiotic resistance from wastewater treatment plants," he said.

The Rice lab showed its spheres -- cores of bismuth, oxygen and carbon wrapped with nitrogen-doped graphene oxide -- inactivated multidrug-resistant Escherichia coli bacteria and degraded plasmid-encoded antibiotic-resistant genes in secondary wastewater effluent.

The graphene-wrapped spheres kill nasties in effluent by producing three times the amount of reactive oxygen species (ROS) as compared to the spheres alone.

The spheres themselves are photocatalysts that produce ROS when exposed to light. Lab tests showed that wrapping the spheres minimized the ability of ROS scavengers to curtail their ability to disinfect the solution.

The researchers said nitrogen-doping the shells increases their ability to capture bacteria, giving the catalytic spheres more time to kill them. The enhanced particles then immediately capture and degrade the resistant genes released by the dead bacteria before they contaminate the effluent.

"Wrapping improved bacterial affinity for the microspheres through enhanced hydrophobic interaction between the bacterial surface and the shell," said co-lead author Pingfeng Yu, a postdoctoral research associate at Rice's Brown School of Engineering. "This mitigated ROS dilution and scavenging by background constituents and facilitated immediate capture and degradation of the released ARGs."

Because the wrapped spheres are large enough to be filtered out of the disinfected effluent, they can be reused, Yu said. Tests showed the photocatalytic activity of the spheres was relatively stable, with no significant decrease in activity after 10 cycles. That was significantly better than the cycle lifetime of the same spheres minus the wrap.

Researchers at the Beckman Institute for Advanced Science and Technology and the Department of Animal Sciences have collaborated to develop a new technique that can be used to determine the fertility of sperm samples. They hope to further develop the technique for assisted reproductive technology in humans.

The study "Reproductive outcomes predicted by phase imaging with computational specificity of spermatozoon ultrastructure" was published in the Proceedings of the National Academy of Sciences.

"This work is a part of a five-year project to develop dairy cattle that are resistant to heat and diseases in tropical areas. We want to donate these cows to developing countries to increase their food production," said Matthew B. Wheeler, a professor of animal sciences and of bioengineering at the University of Illinois at Urbana-Champaign.

In order to develop these traits in cattle, the researchers need to determine which sperm samples work best for in vitro fertilization.

"Although the males may have sperm that are seemingly perfect, there could be morphological or DNA issues. This collaboration allows us to evaluate the spermatozoa and select the best in terms of fertility," said Marcello Rubessa, a research assistant professor in the Wheeler Group.

Traditional techniques for imaging sperm samples are slow and labor intensive, and involve toxic stains. To circumvent this issue, these two teams used the label-free imaging techniques developed in the Beckman Institute's Quantitative Light Imaging Laboratory to determine what parameters of the sperm make them fertile.

"We knew from the fertilization experiments which sperm samples worked. We used our imaging technique to understand what parameters were important for success," said Mikhail Kandel, a graduate student with the Beckman lab. "We saw that the relationship between the size of the head and the tail of the sperm is an important parameter for fertility."

Additionally, the researchers also improved the speed of the technique. "We used artificial intelligence to automate the process of analyzing these sperm cells," said Yuchen He, a graduate student with QLIL.

The researchers hope to improve the speed of the technique for future analysis. "The motility of the sperm is sometimes fast. Therefore, we need to do the measurements quickly," said Gabriel Popescu, a professor of electrical and computer engineering, and of bioengineering, and the director of the Quantitative Light Imaging Laboratory.

"For many years, we have developed various techniques for label-free imaging knowing that we had to give away molecular specificity," Popescu said. "However, our newly developed phase imaging with computational specificity brings back the molecular specificity via AI, which is harmless and works on live cells. The applications are limitless, but one that truly benefits from absence of chemical stains is the assisted reproduction, as described in this collaborative study."

As the world enters the digital age, ecologists are finding themselves equipped with the tools needed to answer longstanding questions -- tools that previous generations of ecologists could only dream of. Cameras on planes, drones, and satellites provide imagery that can span the globe at sub-meter resolution. Geolocators have shrunk in size while growing more accurate than ever, allowing researchers to track rare and elusive animals. Networks of sensors are recording greenhouse gas emissions, animal calls, wildlife movement and more. At the same time, computing advances are rising to meet the challenge of analyzing terabytes of new data. The presentations listed here feature research that harnesses these high-tech advances in new and exciting ways. All will be presented at the Ecological Society of America's upcoming virtual annual meeting, August 3-6, 2020, and will be available on-demand to registered attendees.

Virtual On-Demand Talks:

Scaling Ecological Insights
https://eco.confex.com/eco/2020/meetingapp.cgi/Paper/88207
For a long time, logistics, technology, funding and computing power have limited the scope of ecological research, leaving us to glean insights from studies that are relatively small in scale. In this opening plenary talk, Lucas Joppa, Chief Environmental Officer at Microsoft, examines some of the barriers to scaling up the science addressing our greatest environmental challenges, and reviews some of the technological advances that are breaking down those barriers.

Machine learning for decision support in wildlife conservation and land management
https://eco.confex.com/eco/2020/meetingapp.cgi/Paper/81580
Crafting a conservation plan for an area or a species is a complicated -- and usually time-intensive -- task. Artificial intelligence (AI) can help speed up the planning process by quickly processing the enormous amounts of data now available from cameras, geolocators, aerial and satellite imagery and other kinds of sensors. In this talk, Dan Morris of Microsoft discusses how two particular tasks central to most conservation planning -- biodiversity monitoring and landcover mapping -- can be aided by AI.

Near real time tracking of fishing activity around the globe
https://eco.confex.com/eco/2020/meetingapp.cgi/Paper/81867
Humans are a top predator in the world's oceans, but we have a poor understanding of our own collective fishing behavior. In this talk, Juan Mayorga explains how he uses satellite tracking to determine where and when nearly 80,000 fishing vessels around the globe sail, fish and refuel -- information that could inform efforts to combat illegal fishing and excessive by-catch.

Integrating multiple remote sensing data types to improve retrieval of essential biodiversity variables
https://eco.confex.com/eco/2020/meetingapp.cgi/Paper/81976
Advanced remote sensing imagery, now available from entities like NASA, the European Space Agency and the National Ecological Observatory Network, is valuable in its own right. But when combined with other forms of data, these new remote sensing products can offer profound new ecological insights. In this talk, Susan Ustin describes how her research incorporates data from different airborne imaging projects to map wetlands and tree distributions with extreme precision, and to document the effect that drought has across entire forests.

Wild robots: Developing DIY technology to investigate soil carbon flux in a long-term, landscape-scale, large herbivore exclosure experiment in a central Kenya savanna
https://eco.confex.com/eco/2020/meetingapp.cgi/Paper/85406
Antelope, bison and other large grazers are known to exert control over carbon cycling in grasslands, which store a substantial portion of the world's carbon. But exactly how large herbivores influence carbon flux from the soil to the atmosphere is poorly understood. In this talk, Elizabeth Forbes discusses her use of automated soil flux chambers -- "fluxbots" -- to pinpoint the locations and conditions under which large African grazers impact carbon cycling the most.

Automatic detection for passive acoustic monitoring of the African elephant
https://eco.confex.com/eco/2020/meetingapp.cgi/Paper/86627
Until recently, researchers and land managers have struggled to monitor the locations and population sizes of animals that are rare, secretive or that live in dense vegetation. Acoustic monitoring, where recorders are placed in potential habitat to pick up animals' calls, are a potential font of information -- but the sheer quantity of recorded data this method generates is daunting. In this talk, Jonathan Gomes-Selman discusses the use of acoustic monitoring to detect African elephants, and a new machine learning algorithm that helps to process the mountains of acoustic data.

Where the wild things are: How wildlife navigate the Wasatch wildland-urban interface
https://eco.confex.com/eco/2020/meetingapp.cgi/Paper/83647
As urban sprawl infiltrates the wildlands around cities, wildlife will either need to adapt to human presence, or flee. Knowing how wild animals respond to humans and our built environment would help conservationists mitigate the effects of sprawl, but monitoring wildlife behavior in these settings has, historically, been a serious challenge. In this talk, Austin Green describes a large community science effort to install and process the data from hundreds of camera traps throughout the Central Wasatch Mountain Range, in order to better understand which species are most impacted by development, and why.

Global patterns of disturbance and functional mammal community assemblage: A TEAM study
https://eco.confex.com/eco/2020/meetingapp.cgi/Paper/85640
Another large camera trapping project, the Tropical Ecology Assessment and Monitoring Network (TEAM) seeks to measure the impact of natural environmental variation and human disturbance on tropical mammal communities around the world. In this talk, Daniel Gorczynski explains how the images from this network of cameras are being used to determine the subtle and not-so-subtle ways that human influence shapes tropical diversity.

Posters:

Bears on film - Two approaches for studying predator-prey interactions yield large amounts of data
https://eco.confex.com/eco/2020/meetingapp.cgi/Paper/83775
Photography and videography are similar technologies, but they each allow researchers to answer very different questions about wildlife. In this poster, Mathieu Leblond and his colleagues describe using them both -- in the form of camera traps and camera collars -- to study black bear predation on caribou.

Drone aerial mapping: Accuracy and limitations for predicting oyster habitat
https://eco.confex.com/eco/2020/meetingapp.cgi/Paper/83811
For environmental mapping, researchers and managers have typically turned to satellite imagery, which offers a view of ecosystems on massive scales, but it often suffers from low resolution. In this poster, Shannon Dolan and her colleagues review the benefits -- and drawbacks -- of using drone-mounted cameras to map eastern oyster reefs along the North Carolina coast.

Land sharing or land sparing? What big data on wildlife-livestock movement, activity and interactions can reveal
https://eco.confex.com/eco/2020/meetingapp.cgi/Paper/88395
In the United States, conservation often means setting aside areas where forms of intensive land use, such as agriculture and grazing, are prohibited. High yields and high wildlife diversity are incompatible, the thinking goes. In this poster, Daniel Rubenstein and his colleagues discuss a different model in Kenya, where cattle and wild grazers share the landscape. Using a slew of high-tech methods -- from camera traps to geolocators to drone imagery -- they address the question: "Do livestock compete with or promote wildlife?"

Age-related hearing loss has more to do with the death of hair cells than the cellular battery powering them wearing out, according to new research in JNeurosci. That means wearing ear protection may prevent some age-related hearing loss.

Every day, people subject their ears and the delicate hair cells -- the cells inside the cochlea that turn sound waves into electrical signals -- within them to damaging noisy environments and too-loud headphones. However, ears also age. Both the hair cells and the stria vascularis, the cellular battery powering them, degrade with age. For 60 years, scientists attributed noise-induced hearing loss to hair cell death and age-related hearing loss to stria vascularis damage. But a new study from Wu et al. proves otherwise: age-related hearing loss in humans stems from hair cell death, not stria vascularis damage.

The research team counted surviving hair cells, auditory nerve fibers, and stria vascularis area in cochlea samples from 120 people and compared the damage to hearing test scores. Hair cell death predicted the severity of hearing loss, while stria vascularis damage did not. This contradicts findings in animal models, where the opposite is true. But animals do not experience the same auditory abuses as humans, which may mean that much of age-related hair cell loss is noise-induced, and therefore avoidable.

In a new study of human ear tissues, hearing scientists have demonstrated that age-related hearing loss, also called presbycusis, is mainly caused by damage to hair cells, the sensory cells in the inner ear that transform sound-induced vibrations into the electrical signals that are relayed to the brain by the auditory nerve. Their research challenges the prevailing view of the last 60 years that age-related hearing loss is mainly driven by damage to the stria vascularis, the cellular "battery" that powers the hair cell's mechanical-to-electrical signal conversion.

The inner ear, where most types of hearing impairment originate, cannot be biopsied, and its delicate structures can only be resolved in specimens removed at autopsy. Understanding the true cellular causes of age-related hearing loss impacts how future treatments are developed and how appropriate candidates will be identified, and can also suggest how to prevent or minimize this most common type of hearing damage, according to the study authors, led by Pei-zhe Wu, MD, a postdoctoral research fellow in Otolaryngology Head and Neck Surgery in the Eaton-Peabody Laboratories at Massachusetts Eye and Ear.

"Our study upends the dogma about the major cause of age-related hearing loss," said Dr. Wu. "Documenting the dominant role of progressive hair cell loss in the hearing impairment of normal aging means that the millions who suffer with this condition could benefit from the hair cell regenerative therapies that are the focus of ongoing research across the world. No one is focusing on approaches to regenerate the stria."

The new study was published online July 20, in Journal of Neuroscience (JNeurosci).

New algorithm and new techniques developed to uncover true cause of age-related hearing loss

Researchers examined 120 inner ears collected at autopsy. They used multivariable statistical regression to compare data on the survival of hair cells, nerve fibers, and the stria vascularis with the patients' audiograms to uncover the main predictor of the hearing loss in this aging population. They found that the degree and location of hair cell death predicted the severity and pattern of the hearing loss, while stria vascularis damage did not.

Previous studies examined fewer ears, rarely attempted to combine data across cases and typically applied less quantitative approaches. Most importantly, prior studies greatly underestimated the loss of hair cells, because they didn't use the state-of-the art microscopy techniques that allowed Wu and colleagues to see the tiny bundles of sensory hairs (> 200 times thinner than a typical human hair), that helped them identify and count the small number surviving hair cells. Prior studies scored hair cells as "present," even if only one or two remained.

Cellular cause behind age-related hearing loss questioned

Age-related hearing loss is one of the most common conditions affecting older adults; about one in three people in the United States between the ages of 65 and 74 has hearing loss, and nearly half of those 75 and older. The condition cannot be reversed and often requires hearing aids or other sound amplification devices.

Previous animal studies suggested that presbycusis is caused by atrophy of the stria vascularis, a highly vascularized cluster of ion-pumping cells, located in the inner ear adjacent to the hair cells. The stria serves as a "battery" that powers the hair cells as they transform sound-evoked mechanical motions into electrical signals. In aging laboratory animals, such as gerbil, there is very little loss of hair cells, compared to humans, even at the end of life. However, there is prominent damage to the stria vascularis, and damage to the stria will, indeed, cause hearing loss. Prior to this new study, most scientists have assumed that the aging gerbil data also apply to human presbycusis.

The researchers say the new findings are good news given recent progress in the development of therapies to regenerate missing hair cells. If presbycusis were due primarily to strial damage, hair cell regeneration therapy would not be effective. This new study turns the tables, suggesting, that vast numbers of hearing impaired elderly patients could likely benefit from these new therapies as they come to the clinics, hopefully within the next decade.

Findings point to importance of protecting ears from sound damage

The data also showed that hair cell degeneration in aging humans is dramatically worse than in animal models of presbycusis. Laboratory animals are aged in sound-controlled enclosures, where they are not exposed to the constant barrage of moderate and high-intensity noises that surround us: those we choose to listen to and those we can't avoid. "The greater hair cell death in human ears suggests that the high-frequency hearing losses that define presbycusis may be avoidable, reflecting mainly accumulated damage from environmental noise exposures," said M. Charles Liberman, PhD, Director, of the Eaton-Peabody Laboratories at Mass Eye and Ear and a co-author of the study. "It's likely that if we were more careful about protecting our ears during prolonged noisy activities, or completely avoiding them, we could all hear better into old age" said Dr. Liberman, who is the Harold F. Schuknecht Professor of Otolaryngology-Head and Neck Surgery at Harvard Medical School.

Researchers from the Okinawa Institute of Science and Technology Graduate University (OIST) have created next-generation solar modules with high efficiency and good stability. Made using a type of material called perovskites, these solar modules can maintain a high performance for over 2000 hours. Their findings, reported 20th July 2020 in leading journal, Nature Energy, have brightened prospects of commercialization.

Perovskites have the potential to revolutionize the solar technology industry. Flexible and lightweight, they promise more versatility than the heavy and rigid silicon-based cells currently dominating the market. But scientists must overcome some major hurdles before perovskites can be commercialized.

"There are three conditions that perovskites must meet: they must be cheap to produce, highly efficient and have a long lifespan," said Professor Yabing Qi, head of the OIST Energy Materials and Surface Sciences Unit, who led this study.

The cost of making perovskite solar cells is low, as the cheap raw materials require little energy to process. And in just over a decade, scientists have made huge strides in improving how effectively perovskite solar cells convert sunlight to electricity, with efficiency levels now comparable to those of silicon-based cells.

However, once scaled up from tiny solar cells to larger solar modules, the efficiency levels of perovskites plummet. This is problematic as commercial solar technology needs to remain efficient at the size of solar panels, several feet in length.

"Scaling-up is very demanding; any defects in the material become more pronounced so you need high-quality materials and better fabrication techniques," explained Dr. Luis Ono, a co-author of this study.

The instability of perovskites is another key issue under intense investigation. Commercial solar cells need to be able to withstand years of operation but currently perovskite solar cells degrade fast.

Building up the layers

Professor Qi's team, supported by the OIST Technology Development and Innovation Center's Proof-of-Concept Program, addressed these stability and efficiency issues using a new approach. Perovskite solar devices are made up of multiple layers - each with a specific function. Instead of focusing on just one layer, they looked at the overall performance of the device and how the layers interact with one another.

The active perovskite layer, which absorbs sunlight, lies in the center of the device, sandwiched between the other layers. When photons of light strike the perovskite layer, negatively-charged electrons harness this energy and "jump" to a higher energy level, leaving behind positively-charged "holes" where the electrons used to be. These charges are then diverted in opposite directions into electron and hole transport layers above and below the active layer. This creates a flow of charge - or electricity - that can leave the solar device via electrodes. The device is also encapsulated by a protective layer that reduces degradation and prevents toxic chemicals from leaking into the environment.

In the study, the scientists worked with solar modules that were 22.4 cm2.

The scientists first improved the interface between the perovskite active layer and the electron transport layer, by adding a chemical called EDTAK between the two layers. They found that EDTAK prevented the tin oxide electron transport layer from reacting with the perovskite active layer, increasing the stability of the solar module.

The EDTAK also improved the efficiency of the perovskite solar module in two different ways. Firstly, potassium in the EDTAK moved into the active perovskite layer and "healed" tiny defects on the perovskite surface. This prevented these defects from trapping the moving electrons and holes, allowing more electricity to be generated. The EDTAK also increased performance by enhancing the conductive properties of the tin oxide electron transport layer, making it easier to collect electrons from the perovskite layer.

The scientists made similar improvements to the interface between the perovskite active layer and the hole transport layer. This time, they added a type of perovskite called EAMA between the layers, which enhanced the ability for the hole transport layer to receive holes.

The EAMA-treated device also showed better stability under humidity and temperature tests. This was due to how the EAMA interacted with the surface of the perovskite active layer, which is a mosaic of crystal grains. In solar devices without EAMA, the scientists saw that cracks formed on the surface of the active layer, which originated from the boundaries between these grains. When the scientists added EAMA, they observed that the additional perovskite material filled the grain boundaries and stopped moisture from entering, preventing these cracks from forming.

The team also modified the hole transport layer itself, by mixing in a small amount of polymer called PH3T. This polymer boosted moisture resistance by providing the layer with water-repellant properties.

The polymer also solved a major issue that has previously hampered improvements to long-term stability. The electrode on top of the perovskite solar module is formed from thin strips of gold. But over time, tiny gold particles migrate from the electrode, through the hole transport layer and into the active perovskite layer. This irreversibly impairs performance of the device.

When the researchers incorporated PH3T, they found that the gold particles migrated into the device more slowly which significantly increased the module's lifespan.

For their final improvement, the scientists added a thin layer of the polymer, parylene, in addition to glass, to provide a protective coating to the solar module. With this added protection, the solar modules maintained about 86% of their initial performance, even after 2000 hours of constant illumination.

In collaboration with Dr. Said Kazaoui at National Institute of Advanced Industrial Science and Technology (AIST), the OIST team tested the improved solar modules and obtained an efficiency of 16.6% - a very high efficiency for a solar module of that size. The researchers now aim to carry out these modifications on larger solar modules, leading the way towards the development of large-scale, commercial solar technology in the future.

Scientists in Australia and the United States have been able to 'upconvert' low energy light into high energy light, which can be captured by solar cells, in a new way, with oxygen the surprise secret ingredient. The results are published in Nature Photonics today.

While the approach's efficiencies are relatively low and more work is needed to achieve commercialisation, the research is an exciting development, according to senior author Professor Tim Schmidt from the ARC Centre of Excellence in Exciton Science and UNSW Sydney.

"The energy from the sun is not just visible light," Prof. Schmidt explains.

"The spectrum is broad, including infrared light which gives us heat and ultraviolet which can burn our skin.

"Most solar cells, charge-coupled device (CCD) cameras and photodiodes (a semiconductor that converts light into electrical current) are made from silicon, which cannot respond to light less energetic than the near infrared.

"This means that some parts of the light spectrum are going unused by many of our current devices and technologies."

To extend the range of sensitivity of these devices, and potentially increase the efficiency of solar cells, one strategy is to 'upconvert light', turning low energy light into more energetic, visible light which can excite silicon.

"One way of doing this is to capture multiple smaller energy photons of light and glue them together," Prof. Schmidt says.

"This can be done by interacting the excitons (bound states of electrons and electron holes that can transport energy without transporting net electric charge) in organic molecules."

Until now, this had never been achieved beyond the silicon band gap, which is the minimum energy that is required to excite an electron in silicon up to a state where it can participate in conduction. However, Exciton Science researchers, based at UNSW Sydney, have resolved this challenge. And they transformed a familiar foe - oxygen - into an unlikely friend to achieve their goal.

Together with collaborators at RMIT University and the University of Kentucky, the researchers used semiconductor quantum dots (nanoscale man-made crystals) to absorb the low energy light, and molecular oxygen to transfer light to organic molecules.

Usually oxygen is detrimental to molecular excitons, but at such low energies its role changes and it can mediate energy transfer, allowing the organic molecules to emit visible light, above the silicon band gap.

Contributing author Professor Jared Cole of RMIT University says: "What's interesting is that often without oxygen, lots of things work well. And as soon as you allow oxygen in, they stop working.

"It was the Achilles heel that ruined all our plans but now, not only have we found a way around it, suddenly it helps us."

The efficiencies are still low, but the scientists have strategies to improve this in the near future.

"This is only an early demonstration, and there's quite a lot of materials development needed to make commercial solar cells, but this shows us it's possible," Prof. Schmidt says.

And lead author Elham Gholizadeh, also of UNSW Sydney, is optimistic about the potential of the work to make a rapid positive impact on the research field.

"As this is the first time we've been successful with this method, we will face some challenges," she says.

"But I'm very hopeful and think that we can improve the efficiency quickly. I think it's quite exciting for everyone. It's a good method to use oxygen to transfer energy.

"Violanthrone doesn't have the perfect photoluminescence quantum yield so the next step will be to look for an even better molecule."

LOGAN, UTAH, USA - Scientists have long debated the idea that global climate changes have forced river erosion rates to increase over the past five million years. New field data gleaned from a multi-institution, collaborative study of North America's rugged Yukon River basin, near storied Klondike goldfields, reveal profound increases in river erosion during abrupt global intensification of climate fluctuations about 2.6 and one million years ago.

"These results provide the first definitive support that increases in sediment deposited to oceans from river erosion coincide with dramatic changes in glacial cycles," says Utah State University geoscientist Tammy Rittenour. "Our ability to date former river deposits was the game-changing factor in allowing us to pursue this hypothesis."

Rittenour and colleagues from the U.S. Geological Survey, the University of Vermont and Purdue University published findings in the July 20, 2020, issue of Nature Geoscience.

"Oxygen isotope values in marine sediment show worldwide fluctuations between cold and warm climates that abruptly intensified during the early Pleistocene period," says Rittenour, professor in USU's Department of Geosciences. "Rates of river sediment accumulation also jumped during this time."

Since rivers do the work of erosion and sediment transport over most of the Earth's surface, scientists have long suggested patterns of global precipitation mimic climate fluctuations.

"If that's the case, enhanced river discharge resulting from intensified global precipitation would increase rates of river erosion," she says.

To test this idea, the team took advantage of the landscape history preserved in the study site's prominent river terraces - ancient river floodplains - perched up to hundreds of meters above the modern Fortymile River, a Yukon River tributary that flows from northwestern Canada to Alaska.

"This 'Rosetta-stone' location, with exposed terraces, provided a long-sought window from which to obtain data," says Rittenour, a Geological Society of America Fellow. "We geochronologists often repeat the adage, 'No Dates, No Rates,' meaning we can't calculate rates of erosion without age control. Using relatively new dating techniques, we were able, for the first time, to establish ages for river deposits that span these key time periods of global climate change."

Co-authors Lee Corbett and Paul Bierman of UVM and Marc Caffee of Purdue provided age control on the site's older terraces, using cosmogenic nuclide burial dating methods that use differing decay rates of unique radiogenic isotopes of beryllium and aluminum produced by sediment exposure to cosmic radiation.

Rittenour, director of USU's Luminescence Laboratory, used optically stimulated luminescence dating of younger river sediments.

"OSL dating provides an age estimate of the last time the sediment was exposed to light," she says.

Corroborating the team's new results, Bering Sea sediment records show concurrent increases in accumulation of sediment eroded from the Fortymile River.

"It's exciting to apply new tools to test foundational ideas that have been only previously speculated," Rittenour says. "These results represent an important step toward understanding the influence of climate in shaping landscapes inhabited by people, and provide clues regarding future landscape response to human activity."

A key uncertainty in climate projections is the amount of carbon emitted by thawing permafrost in the Arctic. Plant roots in soil stimulate microbial decomposition, a mechanism called the priming effect. An international research team co-lead by Frida Keuper from INRAE and Umeå University and Birgit Wild from Stockholm University shows that the priming effect alone can cause emission of 40 billion tonnes carbon from permafrost by 2100. The study was published today in Nature Geoscience.

Permafrost is permanently frozen ground which stores as much carbon as there is in all plants on Earth and in the atmosphere together. The surface of the permafrost thaws in summer, allowing plant and soil life to thrive. When microorganisms breathe, they emit greenhouse gases. Scientists have previously anticipated that rapidly rising temperatures will drive the emission of 50-100 billion ton permafrost carbon by 2100. On top of that, plant roots feed sugar to the microorganisms in the soil, which the microbes can use to break down more soil organic matter - the priming effect - resulting in even higher greenhouse gas emissions.

"We have known about the priming effect since the 1950's, but we did not know whether or not this small-scale ecological interaction had a significant impact on the global carbon cycle", says Research Scientist Frida Keuper, affiliated with the French National Research Institute for Agriculture, Food and Environment, INRAE, and with Umeå University, Sweden.

The team of researchers combined maps of plant activity and data on soil carbon content from the Northern Circumpolar Soil Carbon Database with an extensive literature survey on priming and plant root properties, to estimate the priming effect in permafrost ecosystems and its influence on greenhouse gas emissions.

They show that the priming effect increases soil microbial respiration by 12 percent, which causes the additional loss of 40 billion ton carbon by 2100 compared to current predictions for permafrost. This equals almost a quarter of the remaining 'carbon budget' for human activities to limit global warming to max 1.5°C.

"These new findings demonstrate how important it is to consider small-scale ecological interactions, such as the priming effect, in global greenhouse gas emission modelling", says Birgit Wild, Assistant Professor at Stockholm University.