Tech

A new U of T Scarborough study finds male black widow spiders will hijack silk trails left by rival males in their search for a potential mate.

Male black widows will follow chemical cues (pheromones) released by potential female mates, but it was always assumed they would avoid rival males because competition is so fierce.

"We expect males to use female cues to find a potential mate, and use those left by their rivals to avoid them," says Catherine Scott, a PhD candidate in Professor Maydianne Andrade's lab at U of T Scarborough and lead author of the study.

"We found male black widows follow rather than avoid rival males, using their silk trails as highways that rapidly lead them to a female's web, even if they can't smell the female themselves."

The western black widow spider is a venomous spider native to large areas of western North America. The life of a male is nasty, brutal and short. Mate-searching is risky - only 12 per cent of males survive - and few females are receptive to potential mates each night. The males who survive also risk being cannibalized by much larger females before getting a chance to mate.

Andrade says this dual tactic of using female cues and following their rivals appears to benefit males because speed is critical.

"Males are better off competing for the same female instead of risking missing out completely," says Andrade, a renowned expert on the mating habits of cannibalistic widow spiders.

"Courtship can also last for hours, so even if a male isn't the first to arrive on the web, if he gets there quickly enough he may be able to win the competition to be the first to mate."

Scott conducted much of the research for this study in the field with coauthor Sean McCann, partly supported through a crowd-funding campaign, where she tracked hundreds of male western black widows on a Vancouver Island beach.

She found males were able to locate females from up to 60 metres away, despite only being the size of a grain of rice. Surprisingly, males with access to other males' silk trails moved at higher speeds than those only with access to chemical cues from females.

It's not clear whether males are picking up on chemical cues left on their rivals' silk, but it's likely they are since they only follow the silk of other black widows and not from other species.

What is clear is that the presence of a rival's silk indicates a female was signalling with pheromones at some point earlier in the evening. The first male who finds that female will shut down the signal by destroying her web, but Scott points out other males will "eavesdrop" on this earlier conversation by following the silk trail left behind, even if they can no longer smell the female themselves.

The immediate goal of this research is to see how the male black widow spiders use information to win the race to find a mate, but understanding the chemical communication of black widows could have important practical applications. The findings could help eventually develop a pesticide-free way to control black widows in situations where they are considered pests, which is important considering their venom is a neurotoxin in humans.

Scott, who starts a postdoc at Arcadia University in the fall, was surprised to find males following their rivals. Generally, if male animals have a choice between competing over a mate or avoiding competition, they avoid it.

"By studying these spiders in the field we realized they probably never get to make that choice," she says.

While much research in the lab tends to focus on how chemical cues affect courtship behaviour or allows females attract potential mates, she says much less is known about how males find females in the wild.

"It's really difficult to do this type of study in nature," adds Andrade, whose lab has discovered how male black widows will choose well-fed females to avoid being eaten alive, and how they also seek out immature females as a mating strategy.

"When you discover behaviour that seems counterintuitive, it just goes to show that you really need to study this mating behaviour as it happens in nature."

The concept of implicit bias has made its way into the general consciousness, most often in the context of racial bias. More broadly, however, implicit biases can affect how people think of anything -- from their thoughts about cookies to those about white men.

"All the little ways in which our everyday thinking about social stuff is unconscious or uncontrollable," wrote Calvin Lai, assistant professor of psychology in Arts & Sciences at Washington University in St. Louis, in an article in DCist. "The stuff that we don't realize is influencing us when we make decisions."

Along with a broader cultural awareness of implicit bias is idea that the actions that they influence can be changed by eliminating the bias itself.

Change the bias, changes in the behavior will follow. It seems logical enough.

If true, reducing implicit bias could be put to practical use for anything from ending discrimination (removing a bias in favor of white males) to losing weight (dialing down a cookie bias).

In a meta-analysis of research papers published on the subject of implicit bias, however, Lai found that the evidence does not show this kind of causal relationship.

The research is published in the Journal of Personality and Social Psychology.

Lai worked with Patrick Forscher, of the University of Arkansas, to systematically review 492 studies that dealt with changing people's "automatic mental processes," the uncontrollable, unconscious mental processes that have come to be known in particular contexts as "implicit bias."

The studies contained more than 87,000 participants. After crunching the numbers, Lai and Forscher saw that studies suggest biases can, in fact, be changed -- although not dramatically.

When they honed in, looking at 63 studies that explicitly considered a link between changes in bias and changes in actions, however, they found no evidence of a causal relationship.

"We definitely didn't expect this," Lai said. "And it challenges assumptions about the relationship between implicit bias and behavior."

Lai suggested four possible reasons that a link was not established in the meta-analysis:

Measurement errors: The way outcomes were measured may have picked up on changes unrelated to the underlying bias. For example, Lai said, such a measurement would be analogous to "moving the mercury around within a thermometer rather than changing the heat in the room."

Confounds: After tests to measure an implicit bias, something happened, unrelated to the changed subjects' behavior.

Measured too narrow of a bias: Appeared to assess the same associations, but maybe the effects were too broad to capture a change associated with the change in bias. For example, the implicit bias measured was about broad attitudes toward White vs. Black people, but the behaviors measured were about behavior toward a specific person of a particular race. In that case, the attitude measured may have been too general.

No causal relationship: Implicit bias doesn't affect behavior at all.

This last option doesn't sit well with Lai. "It would open a theoretical can of worms because there are decades of experiments in other lines of research showing evaluation without conscious intention or control," he said.

However, Lai said there is a more effective way to change these behaviors; one that doesn't rely on changing people's implicit biases: ridding society of the features that cause people to act in a biased way.

For example, reducing subjectivity makes it more difficult for a person's biases to affect decision-making. Instead of relying on a "gut feeling" for a hiring decision, for example, lay out the requirements first, and stick to them.

Or, in the cookie realm, don't have any on hand -- not at home or at the office -- and don't drive past the bakery on the way home.

On an individual level, Lai said, "Equip people with strategies to resist the environment's biasing influence.

"The power of counterstereotypes is not to be underestimated," Lai wrote in a paper describing possible ways to counteract implicit biases. "And if counterstereotypical encounters become typical, shift in attitudes and beliefs will follow."

Lai points out that this study was heavily constrained by the available literature. The studies they included focused on brief interventions and assessments and was heavily skewed toward a certain demographic: university students.

"At this time, we can't distinguish between these potential explanations for the results," Lai said. "Carefully controlled studies need to be conducted to rule out - or rule in - these explanations."

Infrared imagery from NASA's Aqua satellite revealed Tropical Storm Erick is being battered by wind shear, and that its strongest storms were south of the Big Island of Hawaii. NOAA forecasters used other NASA satellites to find Erick's center.

In the National Hurricane Center (NHC) Discussion of Erick on August 2 at 11 a.m. EDT (1500 UTC), Forecaster Jelsema noted that the NHC utilized data from two NASA satellites to find Erick's center. The Discussion noted "Although the center was difficult to locate overnight due to high level cloud cover moving over the low-level center of circulation, a timely GPM (Global Precipitation Measurement mission) pass at 7:36 a.m. EDT (1136Z) and a Visible Infrared Imaging Radiometer Suite (VIIRS) pass at 7:40 a.m. EDT (1140Z) assisted in locating the center." VIIRS is an instrument aboard NASA-NOAA's Suomi NPP satellite.

In addition, NASA's Aqua satellite used infrared light to analyze the strength of storms and found the bulk of them in the southwestern quadrant of Erick, and south of the Big Island of Hawaii. . Infrared data provides temperature information, and the strongest thunderstorms that reach high into the atmosphere have the coldest cloud top temperatures. Cloud top temperatures that cold indicate strong storms with the potential to generate heavy rainfall. Those strongest storms were south and southeast of the center of the elongated circulation.

On August 2 at 7:50 a.m. EDT (1150 UTC), the Moderate Imaging Spectroradiometer or MODIS instrument that flies aboard NASA's Aqua satellite found those strongest storms had cloud top temperatures as cold as minus 80 degrees Fahrenheit (minus 62.2 Celsius).

NHC noted that "Deep convection has managed to develop over the low level circulation center (LLCC) of Erick this morning, after the center was exposed for much of the night. Strong west-southwesterly vertical wind shear continues to affect the tropical cyclone."

At 11 a.m. EDT (5 a.m. HST/1500 UTC), the center of Tropical Storm Erick was located near latitude 16.8 degrees north latitude and 157.4 degrees west longitude. That's about 250 miles (405 km) southwest of Hilo, Hawaii. Erick is moving toward the west-northwest near 14 mph (22 kph) and this general motion is expected to continue through tonight. A turn toward the northwest and a decrease in forward speed is expected over the weekend. On the forecast track, the center of Erick will pass by well to the south of the main Hawaiian Islands today and tonight. The estimated minimum central pressure is 1,000 millibars.

Maximum sustained winds are near 50 mph (85 kph) with higher gusts. Some gradual weakening is forecast during the next couple days. Erick is expected to become a tropical depression by Sunday, and a post-tropical remnant low Sunday night.

Swells generated by Erick will continue to affect the Hawaiian Islands today, producing dangerous surf conditions, mainly along east and southeast facing shores. In addition, rain associated with Erick will continue to spread over portions of the Hawaiian Islands through early Saturday (Aug. 3), bringing the potential for localized heavy rainfall. Total rainfall amounts of 4 to 8 inches are possible, with localized higher amounts.

Erick is forecast to weaken into a tropical depression by Sunday, and become a post-tropical remnant low Sunday night. Dissipation into a trough (elongated area of low pressure) is now forecast to occur by Monday night.

Soft robots have gained much attention in the past several years for their unique characteristics compared to traditional rigid robots. However, unlike the Baymax in the film "Big Hero 6", state-of-the-art soft robot is just a prototype in labs, usually tethered, which means it requires an electrical wire or pneumatic tubing for powering. To exploit the full potential of soft robots, untethered design is preferred. Existing approaches to equip the soft robots with untethered design usually involve high energy-density powering sources, which leads to integration problems, otherwise the robot will be bulk and clumsy for carry low energy-density power sources.

In nature are enormous creatures who have evolved for billions of years for surviving. Rove beetles in genus Stenus, a type of terrestrial insects lives around pools or streams, would gain a burst of kinetic energy to escape when they accidentally fell onto the water, by secreting chemicals to generate a surface energy gradient. Such a propulsive process, commonly known as Marangoni Propulsion, was adopted by live creatures, so it was mild and gentle, completely compatible with soft materials.

In a new research article published in the Beijing-based National Science Review, scientists at Huazhong University of Science & Technology report an untethered fully soft robot in liquid whose actuation employs environmental energy gradients. By releasing environmental active materials (EAMs) to the liquid environment, the robot could gain an agile speed of 5.5 body lengths per second, which is 7 times higher than the best reported value in the untethered soft robotic fish.

"A few advantages occur by adopting such aß mechanism, such as quietness, no thermal fatigue and so on." Prof. Zhigang Wu said, "More importantly, the actuation and the robot functional realization can be complemented separately. The designer, for the first time, gains the opportunity to focus on the function realization. This might enable the soft robot in some untouched scenarios in the future."

Thunderstorms are common all over the world in summer. As well as spoiling afternoons in the park, lightning, rain and strong winds can damage power grids and cause electricity blackouts. It's easy to tell when a storm is coming, but electricity companies want to be able to predict which ones have the potential to damage their infrastructure.

Machine learning - when computers find patterns in existing data which enable them to make predictions for new data - is ideal for predicting which storms might cause blackouts. Roope Tervo, a software architect at the Finnish Meteorological Institute (FMI) and PhD researcher at Aalto university in Professor Alex Jung's research group has developed a machine learning approach to predict the severity of storms.

The first step of teaching the computer how to categorise the storms was by providing them with data from power-outages. Three Finnish energy companies, Järvi-Suomen Energia, Loiste Sähkoverkko, and Imatra Seudun Sähkönsiirto, who have power grids through storm-prone central Finland, provided data about the amount of power disruptions to their network. Storms were sorted into 4 classes. A class 0 storm didn't knock out electricity to any power transformers. A class 1 storm cut-off up to 10% of transformers, a class 2 up to 50%, and a class 3 storm cut power to over 50% of the transformers.

The next step was taking the data from the storms that FMI had, and making it easy for the computer to understand. "We used a new object-based approach to preparing the data, which was makes this work exciting" said Roope. "Storms are made up of many elements that can indicate how damaging they can be: surface area, wind speed, temperature and pressure, to name a few. By grouping 16 different features of each storm, we were able to train the computer to recognize when storms will be damaging".

The results were promising: the algorithm was very good at predicting which storms would be a class 0 and cause no damage, and which storms would be at least a class 3 and cause lots of damage. The researchers are adding more data for storms into the model to help improve the ability to tell class 1 and 2 storms apart from each other, to make the prediction tools even more useful to the energy companies.

"Our next step is to try and refine the model so it works for more weather than just summer storms," said Roope, "as we all know, there can be big storms in winter in Finland, but they work differently to summer storms so we need different methods to predict their potential damage"

An international collaboration led by scientists at Tokyo University of Agriculture and Technology (TUAT) , Japan, has found that hazardous chemicals were detected in plastics eaten by seabirds. This suggests that the seabird has been threatened by these chemicals once they eat plastics.

The research findings were published in Marine Pollution Bulletin in May 2019.

The researchers carried out non-target survey of additives in 194 pieces of plastics ingested by seabirds, such as Northern Fulmar and Albatross. These additives, which are often hazardous chemicals, are generally blended into most plastics in order to make plastics better, for instance to stabilize polymers against UV degradation or oxidation, to simply add colors, and so on.

"We uncovered that 4 kinds of UV stabilizers and 2 brominated flame retardants at detection frequencies of 4.6% and 2.1%, respectively" said Dr. Hideshige Takada, the corresponding author and professor in the Laboratory of Organic Geochemistry of TUAT. "Our previous researches showed that these additives in plastics are transferred from ingested plastics and unfortunately accumulated in some tissues of seabirds."

"These findings imply that any of these additives can be detected in the tissue of seabirds which ingest 15 pieces of plastics with probability of 73%. We found that ingestion of 15 pieces of plastics per one individual is actually happening in the real-world case of the Albatross.", said Dr. Takada. "We could foresee in the near future that 90 % of the individuals would accumulate additives derived from ingested plastics if the number would increase double, that is 30 pieces per individual."

The present study was supported by a Grant-in-Aid from the Ministry of Education and Culture of Japan (Projects No. 26-8120 and No. 16H01768) and Environment Research and Technology Development Fund (SII-2-2).

Scientists worldwide work tirelessly to advance human knowledge and discoveries. One estimate suggests that about three million research articles are published each year, spread across some 30,000 journals.

Despite the quantity, however, many think that improvements can be made to the research culture to bring forth even more significant impact on the world.

To explore the way to go and share best practices, about 700 researchers, teachers, leaders of funding agencies, government officials, journal editors etc. from 60 countries gathered at the 6th World Conference on Research Integrity held at the University of Hong Kong between June 2 and 5. Entitled New Challenges for Research Integrity, the conference heard enriching views on improving the current system for funding research and rewarding faculty.

Among the plenary speakers were Australia's Chief Scientist Alan Finkel; Dr David Moher, Associate Professor from the School of Epidemiology and Public Health at the University of Ottawa; Professor Mai Har Sham, Associate Vice-President (Research) of HKU and co-chair of the organizing committee for the conference, and Dr Maura Hiney, the Head of Post-Award and Education at the Irish Health Research Board. They agreed on moving away from the current, long established practice of assessing research efforts on the basis of metrics predominantly the number of publications and citations in academic journals.

Dr Finkel noted that there are more than 20,000 retracted papers in the Retraction Watch database, which reflects a need for strengthened quality control. "Research institutions have to be more explicit in conveying the message to their research staff that quality counts," he said.

He suggested the Rule of Five for funding agencies and institutions, namely that aspiring researchers should be asked to submit only their best five papers over the past five years, accompanied by a description of the research, its impact and their individual contribution. To ensure quality, agencies should only consider research that has been published in journals compliant with Publication Process Quality Assurance (PPQA) guidelines or those developed by organisations like COPE - the Committee on Publication Ethics.

"Higher levels of PPQA could pick up on the Transparency and Open Promotion guidelines, known as the TOP guidelines, compiled by the Centre for Open Science, or the Reproducibility and Replicability in Science recommendations published this year by the National Academies of Science, Engineering and Medicine," he explained.

Dr Finkel singled out Australia's National Health and Medical Research Council (NHMRC) as an example of a granting agency thoughtfully and deliberately shifting the incentives to strengthen the system. The Rule of Five is now in place for some NHMRC grant schemes - and in future, it may well be extended.

Based on the principle of "follow the money", Dr Finkel also recommended that granting agencies should make proof of research integrity training a requirement for applying for a grant - a call echoed by other speakers.

The conference saw the release of the Hong Kong Principles for Assessing Researchers: Fostering Research Integrity - intended to serve as guiding principles to help institutions improve the current system of faculty incentives and rewards.

Co-author Dr David Moher noted the common frustration with the prevailing "Publish or Perish" culture, which he claims exacerbates the pressure on academics and causes some to engage in duplication, use poor methodology, research design or other practices that could undermine the credibility of their scientific endeavours. "There is evidence that researchers will tailor their publication practices and behaviours in order to advance their career," said Dr Moher.

The five Hong Kong Principles include 1, Assess researchers (and institutions) on responsible practices from conception to delivery, including the development of the research idea, research design, methodology and execution and effective dissemination; 2, Value the accurate and transparent reporting of all research, regardless of the results and reward honest and transparent reporting ; 3, Value the practices of open science - such as open methods, materials and data - when feasible; 4, Value a broad range of research and scholarship, such as replication, synthesis, and meta-research; 5, Value a range of other contributions to responsible research and scholarly activity, such as peer review for grants and publications, mentoring, outreach, and knowledge transfer.

Dr Hiney defines research integrity as the collective responsibility of researchers, funding agencies, institutions. "It is inward facing, addressing quality, reliability, trustworthiness of the research output and outcome, with which we are moving towards innovation, translation of research innovations."

Professor Sham supports the idea of incorporating research integrity training into the graduate curriculum. It is equally important, she adds, that ranking agencies put the same weight on the proposed values in their assessment of institutions.

New research from the Center for Conservation Innovation (CCI) at Defenders of Wildlife, published in the journal Nature Communications, shows for the first time the importance of expert agencies to protecting imperiled species. This paper, "Data Indicate the Importance of Expert Agencies in Conservation Policy," empirically supports the need for strong oversight of federal activities. It also suggests data-driven ways to improve efficiency without sacrificing protections. This is critical at a time when conservation laws and policies are under attack: understanding what works in conservation is essential in combatting the global biodiversity crisis.

The data analyzed by Defenders of Wildlife included every Endangered Species Act section 7 consultation between federal agencies and the National Marine Fisheries Service (NMFS) from 2000 through 2017. The analysis showed that agencies and NMFS agreed on how proposed federal projects would affect listed species most of the time, and that the consultation process rarely stops projects. Importantly, however, federal agencies underestimated the effects of their actions on listed species in 15% of consultations, relative to what species experts at NMFS concluded. This included 22 extreme cases where NMFS concluded the action would jeopardize the very existence of 14 species after the agency had determined its action would do no harm. In 6% of cases, agencies overestimated the effects of their actions, which meant additional resources may have been unnecessarily spent in analyses.

"This study emphasizes the critical role that the expert biologists at the Services play in assessing the impacts of proposed federal actions on threatened and endangered species," said Michael Evans, CCI Senior Conservation Data Scientist and lead author on the study. "Our findings show that limiting or removing the Services from the consultation process could have disastrous consequences for imperiled species. And at the same time, we were able to identify areas where the consultation process could be made more efficient, without sacrificing protections to listed species."

"Recent proposals to 'streamline' consultations by removing the species experts in the National Marine Fisheries Service from the process could be devastating to the species who need protection the most," said Jacob Malcom, Director of the Center for Conservation Innovation at Defenders of Wildlife and an author on the study. "Rather than try to cut protections, Congress should be strengthening and fully funding the expert agencies--National Marine Fisheries Service and the U.S. Fish and Wildlife Service--who ensure the protections for threatened and endangered species."

A combination of waste materials supplemented with a product of biomass could help in the search for high quality soils, a new study suggests.

Soil degradation is posing a huge threat to global food security and every year, around 12 million hectares of cropland are lost to soil erosion.

Scientists from the University of Plymouth have demonstrated that adding biochar - a solid, carbon-rich material derived from biomass - to soil constructed from waste materials, reduces the loss of essential nutrients such as nitrogen and carbon.

This, they believe, can improve the sustainability of manufactured soils by enhancing conditions suitable to sustain plant growth, by improving moisture content, nutrient retention and carbon storage capacity.

It will also lower the soil's dependence on intensive fertiliser applications, reducing both cost and the risk of pollution from the excessive leaching of nitrogen.

The study, published in Science of the Total Environment, focused on a soil composed of waste materials, which has been deployed to support a variety of plants within natural and artificial environments over an 18-year timescale.

However, its success has relied on regular fertiliser applications to supply the required nutrients so the research objective was to measure the effect of biochar application on the retention of macronutrients over the experimental period.

Postdoctoral Research Fellow Dr Kate Schofield, who led the research, said: "Manufactured soils are a growing component in the fight for global food security. But for them to be effective and sustainable, they must retain and cycle nutrients without the need for significant fertiliser inputs. This study has shown that, by combining waste material with pyrolysed biomass (charcoal), the amount of nutrients escaping can be significantly reduced. It is a promising first indication that sustainable soils from waste can be generated and something we are now looking to build on through our current research."

Mineral and organic waste materials, derived from a range of industries and activities, have the potential to be reused as components of manufactured soils.

Their uses include the manufacture of topsoils for urban grasslands and as materials for the horticulture, agriculture, amenity and restoration markets.

Through its FABsoil project, the University - in partnership with the world famous Eden Project and businesses in Cornwall, such as the Green waste Company - is leading the quest to fabricate soils which could ultimately lead to the creation of custom-made, sustainable products across a range of locations and markets.

It has received funding from Agri-Tech Cornwall, a three-year £9.6 million initiative part-funded by the European Regional Development Fund, with match-funding from Cornwall Council.

FABsoil project leader Mark Fitzsimons, Professor of Environmental Chemistry, added: "There isn't a community in the world that doesn't rely on soil. But with global population growth and demand we are currently facing the genuine prospect of a soil crisis. The manufacture of high value soils from waste materials offers international opportunities in terms of food security, carbon sequestration and achieving a circular economy. However, it is crucial that whatever soil we create is sustainable in the long-term and that is one of the key ongoing challenges our research aims to meet."

Science Team Manager at the Eden Project Dr Rachel Warmington, who was not involved with the study but is part of the FABsoil project, added: "Since the Eden Project opened in 2001, we have been successfully growing plants in soils manufactured from waste materials. This research shows how soil 'recipes' can be developed to reduce fertiliser inputs and will be a vital component of future landscape restoration projects."

There’s a species of poison frog called the “strawberry poison frog” or the “blue jeans frog,” depending on who you ask. These frogs are smaller than a quarter, with bright red bodies and navy blue limbs, and they live in shady Costa Rican forests. Or, they did, until humans began cutting the forests to create farmland. These sunny fields and pastures are hotter and drier than the forests, and scientists wanted to know how the strawberry frogs were adapting to their new environment. To figure it out, the researchers built mini temperature-controlled frog habitats to see what temperatures the frogs gravitated towards. They discovered that frogs from sunny pastures tend to seek out higher temperatures than their forest friends—but the ceiling for temperatures they can survive hasn’t changed.

The project was led by two students working on NSF-funded Research Experiences for Undergraduates, first author Juana Rivera-Ordonez (University of Washington) and Adrian Manansala (University of Guam), and their mentors, Justin Nowakowski (University of California, Davis) and Michelle Thompson (Field Museum). The research overseen by senior author Brian Todd of UC Davis.

“We’re trying to understand what happens to species when we transform forests for human land uses,” Nowakowski, one of the corresponding authors of a paper on the project in the journal Biotropica. “For this study, we were trying to understand how strawberry poison frogs that live in these converted pastures handle warmer temperatures in these land uses compared to individuals that live in the forest.”

“We found that if there’s an increase in temperature, there may be some ability to acclimate or adapt, but in situations where temperatures change drastically, it may be bad news for them,” says Thompson, a conservation ecologist and herpetologist at the Field Museum in Chicago and one of the co-authors of the study.

“Amphibians are really dependent on the environment for their body temperature—therefore, they’re really impacted by changes to the environment,” explains Thompson, who began work on the study at Florida International University. Unlike birds and mammals that can heat their own bodies to a constant temperature (like how humans stay around 98.6° F whether we’re in a blizzard or a sauna), frogs are “cold-blooded.” To survive in forests converted into fields and pastures, the strawberry poison frogs (aka Oophaga pumilio) camp out in the few remaining shady places like isolated trees and fallen logs.

“To do this study, we went out into pastures and the forest and measured the air temperature, and we took the temperature of frogs using an infrared thermometer—it’s like a gun that takes the temperature of the frog and the substrate where the frog was,” says Nowakowski. “When you go into the forest, it’s really much cooler, more humid. In the pasture, you get a taste of what these frogs experience, because it’s incredibly hot, and you really want to spend all your time under a tree.”

“The forest has more shade, so sometimes the frogs can be found out in the open, on trees, or by digging through leaf litter. It was harder to find them in open pastures because the frogs have to really find ways to avoid prolonged sunlight exposure,” says Adrian Manansala, a recent graduate of the University of Guam and one of the undergraduate authors of the paper. “The fact that our study species is a vibrant red color made it easier to spot compared to other species that might blend in to the environment. Our mentor also showed us the sound our study species makes, so after some practice we were able to distinguish the sound from others and follow these sounds to help us find them.”

“To find the frogs we walked slowly, gently moving around the leaf litter to make the frogs move which allowed us to spot them,” says Rivera-Ordonez, the paper’s first author. “It was hard to catch them, especially without touching them. It was essential not to touch them since they are very small and their body temperature, what we were measuring, would change upon touching them.”

After recording the temperatures of 111 frogs in the wild, the researchers caught 32 of the frogs by hand and brought them back to the laboratory for further research. (While some species of poison frogs are dangerous to touch, strawberry poison frogs are toxic if eaten, but safe to handle.) In the laboratory, the researchers delved into a trickier-to-measure metric: the frogs’ preferred temperature.

Since they couldn’t just ask the frogs what temperature they like the thermostat set to, the researchers built temperature-controlled experimental habitats using aluminum catering pans, sand, ice packs, and heating pads. “We were using whatever supplies are available in this rural area and MacGyvering it together,” says Nowakowski.

The resulting frog enclosures were long rectangles with a temperature gradient, with one cold end and one hot end. The researchers put each frog into the enclosure for two and a half hours and observed the temperature where the frogs preferred to hang out. They found that the frogs taken from warm pastures chose to spend their time in a warmer part of the enclosure, while the forest frogs preferred a slightly cooler environment.

But while the frogs changed their preferred temperature, the maximum temperature they could withstand didn’t change. To test the frogs’ heat tolerance, they were gently exposed to rising heat levels. The researchers stopped at the first sign that the frogs were under stress: no longer righting themselves when put on their backs. (The frogs weren’t harmed and were released back into the wild after the study ended.)

No matter where they were from, the frogs got too hot at about the same temperature. That means that while the frogs can adapt to have different preferred temperatures based on what they’re used to, the upper limit of what their bodies can tolerate is a hard line. “It appears that for the time being, this species can eke out a living in these converted habitats using different behaviors to avoid extreme temperatures. But this is all subject to change,” says Nowakowski. “On top of habitat change, temperatures are rising due to climate change. We don’t expect things to stay at the status quo—these frogs are bumping right up against their thermal tolerances, and it’s unclear whether they’ll persist or not.”

The frogs’ maximum temperature limit being seemingly fixed makes long-term climate changes more dangerous for them, but Thompson notes that there is hope in the way the frogs can adapt on the short term to habitat change.

“In the current biodiversity crisis that we’re a part of, we have to think of ways to make changes for positive impact,” says Thompson. “This is something we can act on. Where habitat conversion cannot be avoided, leaving small pockets of vegetation will let small populations of frogs persist. It shows that people can make a change.”

And in addition to the potential of the study to help frogs and other animals, the researchers emphasize the importance of the REU program the students took part in. “You can learn a lot about science and research in the classroom, but it’s really all abstract until you go into the tropical forest or the laboratory,” says Nowakowski. “You learn how to develop questions and collect data to answer those questions. For students, it can be really transformative and eye-opening.”

“The REU was an unforgettable experience,” says Manansala. “Before this research program, I had never caught frogs or even held one before, so doing this research was a very new experience for me. This program was my first time conducting an independent study and before this, I had never thought of using creative ways to conduct research such as using a tea kettle and buckets of ice cubes to manually control the temperature of a lab trial. This program taught me research skills and knowledge that I still use today and will continue to apply in a future career in science.”

“One distinct aspect of an REU is how as an undergrad you are able to do more than the data collection. In this program you work with a mentor to develop questions, design the experiments, carry them out, and interpret your results. This makes a huge difference for students and gave me the opportunity to extend this work into my senior thesis, eventually leading to this publication,” says Rivera-Ordonez. “This experience was a great step towards my goal of attending graduate school and it allowed me to solidify my interest in herpetology and in the study of how human driven changes affect them.”

Journal

Biotropica

Researchers have developed a 'FRESH' new method of 3D printing complex anatomical structures out of collagen - a primary building block in many human tissues. The method demonstrates 3D printing of complex collagen-based cardiac structures and tissues that closely mimic the form and function of those in the human heart. Despite its great potential, the widespread use of 3D printing techniques in biomedical applications has been hindered by technological limitations, including poor tissue fidelity and low print resolutions. As such, printing with living cells or creating soft biomaterials such as collagen - two highly sought-after goals - has proven difficult. Here, Andrew Lee and colleagues describe a new method to directly 3D bioprint collagen. The authors, who first put forward their FRESH approach in 2015, developed an improved, second iteration of the "freeform reversible embedding of suspended hydrogels" (FRESH v2.0) 3D bioprinting technique, which uses rapid changes in pH to cause extruded collagen to solidify with precise control. The method can create complex structural and functional tissue architectures that can be further embedded with living cells or complex vasculature at printing resolutions up to 10 micrometers. Lee et al. used this approach to create human heart parts entirely from collagen and human cells, including cardiac tissue, contractile ventricles and even a neonatal heart. Bioprinted hearts accurately reproduced patient-specific MRI anatomical structures, the authors report, following a validation study, while cardiac components printed with human cardiac muscle cells achieved advanced contractile functionality, they say. In a related Perspective, Queeny Dasgupta and Lauren Black III review past advancements in 3D bioprinting and the "unprecedented promise" Lee et al.'s work shows for the future.

Hurricane Erick continued hold onto its status as it moved west through the Central Pacific. NASA-NOAA's Suomi NPP satellite passed overhead and found two small areas of very strong thunderstorms, showing Erick still had some punch left in it.

Fortunately, Erick is a small hurricane and the National Hurricane Center expects those winds to be 200 miles from Hawaii as it passes the islands.

The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard Suomi NPP provided an infrared image of the storm. Infrared imagery reveals cloud top temperatures, and the higher the cloud top, the colder it is, and the stronger the storm. On July 31 at 7:30 p.m. EDT (2330 UTC). There were two small areas within where cloud top temperatures were as cold as minus 80 degrees Fahrenheit (minus 62.2 Celsius). Storms with cloud tops that cold have been found to generate heavy rainfall.

At 11 a.m. EDT (5 a.m. HST/1500 UTC), the center of Hurricane Erick was located near latitude 15.9 degrees north and longitude 152.4 degrees west. That's 315 miles (510 km) southeast of Hilo, Hawaii.

Erick is moving toward the west-northwest near 15 mph (24 kph), and this general motion is expected to continue over the next couple of days. Maximum sustained winds are near 85 mph (140 km/h) with higher gusts. Significant weakening is forecast during the next couple of days, and Erick is expected to weaken to a tropical storm later today. The estimated minimum central pressure is 981 millibars.

Erick's hurricane-strength winds are in a small area. Hurricane-force winds extend outward up to 25 miles (35 km) from the center and tropical-storm-force winds extend outward up to 105 miles (165 km). The National Hurricane Center said that on the forecast track, the center of Erick will pass within about 200 miles south of the Big Island of Hawaii later today and tonight, August 1.

For updated forecasts, visit: http://www.nhc.noaa.gov

If there is any consolation to be found in cancer, it may be that the devastating disease dies with the individual carrying it. Or so it had long been assumed. Recent research however has uncovered some forms of cancer that are transmissible, jumping from one host to another. Indeed, one such contagious cancer, known as canine transmissible venereal tumor (CTVT), has managed to persist in dogs for thousands of years.

In a new commentary appearing in the August 2nd issue of the journal Science, Carlo Maley and Darryl Shibata describe the dynamics of this sexually transmitted disease, which arose in a single ancient animal, living as much as 8.5 millennia ago.

Intriguingly, the exploration of long-term, multi-generational cancer evolution in CTVT may shed new light on how human cancers evolve during the typical course of the disease and may inspire new approaches to treating cancer, which remains the second leading cause of death worldwide.

"Cancers evolve, and our strategies for managing cancer need to take that into account," Maley says. In the future, we hope to maintain long-term control over these evolving tumors. CTVT is fascinating because it shows us how cancers might evolve over the long term."

Maley is a researcher in the Biodesign Center for Biocomputing, Security and Society, the Center for Immunotherapy, Vaccines and Virotherapy and the Center for Mechanisms of Evolution at Arizona State University, as well as ASU's School of Life Sciences. He is the director of the newly established Arizona Cancer and Evolution Center (ACE). Shibata is a professor in the Department of Pathology at USC and the co-director of the ACE Center.

Ominous signs emerge

Examples of contagious cancers in humans exist, but they remain exceedingly rare and have never spread beyond a second host. Other animals however are less fortunate and may fall prey to a range of transmissible cancers, which vary in the severity of their impact.

In 1996, a mysterious illness began sweeping through animal populations in the central highlands of Tasmania. The island's Tasmanian devils were dying from a gruesome facial tumor. At first, a virus was the suspected culprit in the rapidly spreading epidemic. But when the DNA fingerprints of afflicted devils were examined, researchers made a remarkable discovery. The tumor cells were genetically distinct from the devil's own healthy cells, yet they matched tumor cells taken from other Tasmanian devils with the facial tumor disease. It was as though the tumor cells had been cloned and transplanted into each stricken animal. The disease was positively identified as an aggressively lethal, transmissible cancer.

The current commentary concerns CTVT, which causes grotesque, oozing tumors that afflict the genital area in dogs. When researchers sequenced cells from these tumors, the results mirrored those observed in the Tasmanian devils. All of the cancer cells shared a suite of genetic variants that did not appear in the dogs' healthy cells. This led to a startling conclusion: CTVT is not simply a disease that occasionally develops in dogs. It arose only once, in a single dog and has been transmitted through the ages from one animal to the next ever since.

When two dogs with CTVT were examined, one in Brazil and another in Australia, each belonging to a different breed, their tumor cells shared nearly 2 million mutations that were not found in normal canine DNA. While the CTVT genome diverged considerably from the original dog genome, it remained remarkably stable over time.

Dog years

Unlike the pitiless cancer devastating the Tasmanian devils, CTVT is rarely lethal. Instead, it typically persists for a matter of months before being cleared by the dog's immune system. (See drawing based on genetic sequencing of what the first dog carrying CTVT may have looked like.)

Recent investigations of CTVT, carried out by Adrien Baez-Ortega and colleagues, advance the unusual story of this disease. Their findings appear in the current issue of Science and are the focus of Maley and Shibata's commentary.

Baez-Ortega, a researcher at the University of Cambridge, sequenced tumors from 546 dogs around the world. The results showed the great antiquity of CTVT, which has been transmitted by dogs for 4000 to 8500 years. For evolutionary biologists like Maley and Shibata, the findings are revelatory, in part because CTCV appears to have stopped evolving long before it spread around the world.

New directions

The study of cells derived from transmissible cancers like CTVT provides valuable clues for biologists interested in the development of human cancers. Examining somatic cell evolution around the world and over significant spans of time helps researchers understand the subtle dynamics of the evolutionary processes involved in cancer. (In contrast, observing the life and death of cells over time in an individual patient is very difficult.)

Perhaps the most critical observation resulting from the genome sequencing of CTVT is that cancer is not an inevitably progressive disease. Rather, tumors may reach an optimal state that can stabilize over time, exhibiting little or no additional gains in biological fitness--the ability to survive and reproduce.

Typically, tumors persevere and wreak havoc by generating numerous mutations. While most of these have no effect on cancer cell survival, or are even harmful, a few convey an adaptive advantage to cells, increasing their survivability. These are known as driver mutations and as the name implies, they are responsible for a successful cancer's relentless expansion. Driver mutations generate the cells that are able to resist cancer treatment.

It appears that CTVT has been evolving neutrally after its inception, accumulating mutations that do not affect fitness. The successful development of CTVT in dogs therefore seems to require only a few minor adjustments to the genome. The lack of ongoing natural selection in CTVT also suggests that the disease has not had a significant impact on dog survival and reproduction.

The stability of CTVT over time offers hope that certain slow-growing human cancers resistant to conventional therapy, for example prostate cancer, could be tamed and controlled. This might be achieved through so-called adaptive therapies, which seek to limit tumor growth as opposed to aggressive treatments aimed at total eradication, which invariably select for resistant and often lethal cell variants. A pilot clinical trial to test this approach in metastatic breast cancer will soon start at the Mayo Clinic's Arizona campus, in collaboration with ASU.

It seems likely that ongoing explorations of cell evolution in CTVT will provide further insights into complex cell trajectories and genetic transformations in a range of human cancers and inspire innovative methods of addressing the disease.

"Most cancers can only evolve for a few decades before they die with their host," Maley says. "CTVT is an incredible natural experiment, which showed us that it doesn't take much for a cancer to reach an optimal state. It is amazing that it did not discover additional adaptations over thousands of years, even as it infected all different breeds of dogs in all different environments around the world."

Scientists have taken a major step closer to being able to 3D bioprint functional organs, after researchers devised a method of rebuilding components of the human heart, according to a study published in the August 2nd edition of Science.

The team of Carnegie Mellon University researchers developed an advanced version of Freeform Reversible Embedding of Suspended Hydrogels (FRESH) technology, to 3D print collagen with unprecedented complexity and construct components of the human heart spanning from small blood vessels to valves to beating ventricles. Recently awarded US patent 10,150,258, FRESH technology is now licensed to FluidForm, a startup committed to dramatically expanding the capability of 3D printing.

"We now have the ability to build constructs that recapitulate key structural, mechanical, and biological properties of native tissues," said Prof. Adam Feinberg, CTO and co-founder, FluidForm, and Principal Investigator, Regenerative Biomaterials and Therapeutics Group, Carnegie Mellon, where the research was done. "There are still many challenges to overcome to get us to bioengineered 3D organs, but this research represents a major step forward."

Though 3D bioprinting has achieved important milestones, direct printing of living cells and soft biomaterials has proved difficult. A key obstacle is supporting soft and dynamic biological materials during the printing process in order to achieve the resolution and fidelity required to recreate complex 3D structure and function.

FRESH uses an embedded printing approach that solves this challenge by using a temporary support gel, making it possible to 3D print complex scaffolds using collagen in its native unmodified form. In the past, researchers were limited because soft materials were difficult to print with high fidelity beyond a few layers in height due to sag.

Led by co-first authors and FluidForm co-founders Andrew Lee and Andrew Hudson, the nine members of the Carnegie Mellon team overcame these obstacles by developing an approach that uses rapid pH change to drive collagen self-assembly.

The FRESH 3D bioprinted hearts were based on human MRI and accurately reproduced patient-specific anatomical structure. Smaller cardiac ventricles printed with human cardiomyocytes showed synchronized contractions, directional action potential propagation, and wall-thickening up to 14% during peak systole. Challenges remain however, including generating the billions of cells required to 3D print larger tissues, achieving manufacturing scale, and the as yet undefined regulatory process for clinical translation.

While the human heart was used for proof-of-concept, FRESH printing of collagen and other soft biomaterials is a platform that has the potential to build advanced scaffolds for a wide range of tissues and organ systems.

"FluidForm is extraordinarily proud of the research done in the Feinberg lab" said Mike Graffeo, CEO, FluidForm. "The FRESH technique developed at Carnegie Mellon University enables bioprinting researchers to achieve unprecedented structure, resolution, and fidelity, which will enable a quantum leap forward in the field. We are very excited to be making this technology available to researchers everywhere."

FluidForm is commercializing FRESH technology via its first product, LifeSupport(TM) bioprinting support gel, enabling researchers around the world access to high-performance 3D bioprinting of collagen, cells and a wide range of biomaterials.

Insight on insider trades is tough to come by, but some mutual fund managers have figured out a way to leverage their networks -- and the Securities and Exchange Commission's EDGAR servers -- to better read between the lines when tracking stocks.

New research from the University of Notre Dame found that these tracked insider trades can predict future firm returns, with the stocks bought by a fund manager after a tracked insider buy outperforming other firm purchases.

"IQ from IP: Simplifying Search in Portfolio Choice," forthcoming in the Journal of Financial Economics from lead author Huaizhi Chen, assistant professor of finance in Notre Dame's Mendoza College of Business, examined the monitoring behavior of individual institutional investors at companies like Fidelity Investments and Vanguard Group Inc. using web traffic on the SEC's EDGAR servers from 2004 to 2015.

Chen, along with his co-authors Lauren Cohen of Harvard Business School, Umit Gurun of the University of Texas at Dallas, Dong Lou of the London School of Economics and Christopher Malloy of Harvard Business School, identified which corporate insiders were being tracked based on what trading information portfolio managers downloaded off the site. Using the IP addresses connected with the download, they were able to identify the individual fund managers and compare their portfolio decisions with the behavior of the corporate insider they tracked.

They discovered that when a firm bought after a tracked insider did so, the stock outperformed the firms' other purchases by an annualized abnormal return of 12 percent rate per year. These abnormal returns do not reverse but continue to accrue in following quarters. And when fund managers opted not to buy or sell when a tracked insider did so, the researchers noted, it implies that those insider trades "should have less predictive ability for future returns."

The researchers noticed that the insiders being tracked shared certain characteristics.

"We find that institutional managers tend to track members of the top management teams of firms (CEOs, CFOs, presidents and board chairs) and tend to share educational and location-based commonalities with the specific insiders they choose to follow," Chen said. "They tend to track accountants, people living close to them and people they went to school with. Collectively, our results suggest that the information in tracked trades is important for fundamental firm value and is only revealed following the information-rich dual trading by insiders and linked institutions."

The study also finds "the average tracked stock that an institution buys generates annualized alphas of between 9-18 percent relative to the purchase of an average non-tracked stock."

Chen's research paper took first place in the 17th annual Dr. Richard A. Crowell Prize, which recognizes new and cutting-edge academic research that connects theory and practice in the field of quantitative investing.

"I think the main contribution of the research is to understand how these active asset managers construct and manage their portfolios based on all of the information available," said Chen, who researches in the area of behavioral finance. "In principle, there isn't a lot of direct evidence that managers actively acquire information to be used in portfolio formation. Our paper provides a first step in understanding that."