An international team of scientists — led by the Natural History Museum and the University of Plymouth — carried out the first detailed analysis of gene sequence data for any species of the so-called “blindsnakes” (Scolecophidia), a group of small-eyed burrowers.

They found that seven of the 12 genes associated with bright-light vision in most snakes and lizards species are not present in scolecophidians.

This, they say, demonstrates extensive vision gene loss over tens of millions of years of evolutionary history, similar to that which has also been observed in burrowing mammals with reduced vision.

It also challenges the hypothesis that all snakes living across the world today evolved from extreme burrowers, because the vision genes lost in scolecophidians are present in most other living snakes. The researchers say it would be extremely unlikely for such genetic deficiencies to have been reversed through evolution.

Scolecophidians are dedicated burrowers and form one half of the oldest divergence in the snake tree. They comprise approximately 460 of the approximately 3,850 currently recognised living snake species, and likely diverged from their closest living relatives (Alethinophidia, which includes all other living snakes) more than 65 million years ago.

Scolecophidians are typically small, cylindrical, burrowing snakes with reduced eyes and small mouths, strikingly different from the more familiar alethinophidians, which include pythons, vipers, and cobras.

For this research, published in Genome Biology and Evolution, scientists generated new gene-sequence data for the dark-spined blind snake (Anilios bicolor) and the prong-snouted blind snake (Anilios bituberculatus), both of which are common across southern Australia.

They then compared their results with similar data for functional vision genes among other species of snakes and lizards.

Lead author Dr David Gower, Head of the Life Sciences Vertebrates Division at the Natural History Museum, said: “Our data and analytical results provide clear evidence for very substantial reduction of elements of the visual system of burrowing scolecophidian snakes. We already knew that snakes lost some vision genes and eye structures during their evolution from lizards, but most were nonetheless retained. It is highly unlikely that functional copies of a large number of vision genes were lost from the ancestral snake but subsequently re-evolved in most living snakes. As a result, our study strongly suggests that the ancestor of all living snakes was unlikely to have been as extreme a burrower as living scolecophidian snakes.”

The same team of researchers published a study in May 2020, which revealed that the visual systems of sea snakes have undergone remarkable adaptation to life underwater for 15 million years.

Dr Bruno Simões, Lecturer in Animal Biology at the University of Plymouth, led that research and is senior author on the current study. He said: “The nature of the ancestral snake has been highly debated. It has been suggested that it had evolved a reduced visual system as a result of a possible burrowing ecology. Our research provides new information on the likely ecology and environment of the ancestral snake and suggests that the highly subterranean lives and reduced eyes of living scolecophidian snakes likely evolved as specialisms rather than being the retention of primitive characteristics. This study also shows convergent evolution between subterranean snakes and burrowing mammals with the loss of similar genes, especially those associated with bright-light and colour vision.”

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Materials provided by University of Plymouth. Original written by Alan Williams. Note: Content may be edited for style and length.

The team conducted a set of 100 global Earth system model simulations over 1850-2100, working with a “business-as-usual” scenario for relatively strong emissions of greenhouse gases over the 21^st century. The runs were given different initial conditions, and by virtue of the butterfly effect they were able to represent a broad envelope of possible climate states over 1850-2100, enabling sophisticated analyses of changes in the variability of the Earth system over time. The nominally one-degree (~100km) resolution of the model, in conjunction with the 100-member set of runs, represented an unprecedented set of technical challenges that needed to be met before advancing to the goal of assessing how climate variability is impacted by sustained anthropogenic changes to the climate system. “We met these challenges by using the IBS/ICCP supercomputer Aleph, one of Korea’s fastest supercomputers” says Dr. Sun-Seon Lee from the ICCP, a co-author of the study who ran the simulations together with her NCAR colleague Dr. Nan Rosenbloom. For the project, approximately 80 million hours of supercomputer time were used, and approximately 5 Petabytes of disc space (approximately 5000 normal hard discs) were required for storage of the model output.

The main finding of the study is that the impact of climate change is apparent in nearly all aspects of climate variability, ranging from temperature and precipitation extremes over land to increased number of fires in California, to changes in bloom amplitude for phytoplankton in the North Atlantic Ocean. Each of these changes has important impacts for sustainable resource management. As an example, occurrences of extreme precipitation events over the 21^st century (between 2000-2009 and 2090-2099) indicate that extremes are expected to become more commonplace over many regions. These projected changes in precipitation extremes are in fact representative of the omnipresence of changes in extremes in the future across a broad range of climate and ecosystem variables, which has important implications for future adaptation strategies.

“In addition to large-scale changes in extreme events, our study also identified large-scale changes in the structure of the seasonal cycle over the 21^st century, showing an enhanced growing season length over the continental regions north of 50°N,” says Dr. Keith Rodgers from the ICCP, first author of the study and a co-lead of the CESM2 Large Ensemble Project. Largely due to mean state warming and ensuing changes in the timing of the retreat and advance of winter snow cover, by the end of the 21^st century growing season length is projected to increase by three weeks.

Taken together, the computer simulations reveal that across our planet we can expect widespread changes in climate variability, ranging in timescales from synoptic storms to seasons to that of El Niño to decades. Dr. Gokhan Danabasoglu, a co-author of the study and a co-lead of the project, says “an important step moving forward will be to identify more fully the potential societal impacts and to communicate the implications for adaptation strategies.” This broader study has already motivated a number of more specialized scientific investigations using the tremendous volume of output from the simulations, spanning topics from marine ecosystem impacts to hydrological changes that affect water supply.

The National Center for Atmospheric Research is sponsored by the US National Science Foundation and managed by the University Corporation for Atmospheric Research.

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From animal welfare to environmental sustainability, there are plenty of reasons people choose to avoid eating meat derived from animals. Many current meat alternatives rely on plant-based proteins, most often from soy and wheat, which can readily mimic the texture and nutritional value of the real thing. While 3D printing has already been tested for meat alternatives, none of the current formulations include proteins from these particular plants. So, Songbai Liu and Shanshan Wang wanted to figure out an approach to making a meat “dough” with soy and wheat protein that could be produced effectively with a 3D printer.

The researchers tested soy and wheat proteins in formulations containing several other ingredients using a 3D printer. They evaluated their concoctions based on the accuracy with which the dough could be laid down by the printer and how well it held its form. They also examined its texture and microstructure. The experiments revealed the importance of several additional ingredients, including the emulsifier Tween-80 and sodium alginate to control the texture. Heat-sensitive cocoa butter turned out to be a particularly important ingredient, making the dough more fluid at warm temperatures for printing, but then hardening afterward at room temperature, allowing the dough to retain its printed shape. One drawback, however, is that people who cannot eat wheat gluten or soy because of allergies or celiac disease would not be able to partake of the new alternatives. To address this issue, the researchers attempted to replace the soy protein with that from peas, but the resulting dough was too soft for printing. Even so, these experiments have identified a new strategy for formulating meat alternatives using this versatile technology, according to the researchers.

The authors acknowledge funding from the National Key Research and Development Program, the Zhejiang Public Welfare Technology Research Program, the Qinghai Science and Technology Program and the Foundation of Fuli Institute of Food Science at Zhejiang University.

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Most current drowsiness detection systems use an exterior, forward-looking camera to monitor lane position or sudden, exaggerated corrections. Others use an interior camera to check a driver’s face or eyes for signs of nodding off. Camera-based systems, while useful, have drawbacks. For example, an exterior camera could be blocked by mud, and an interior camera could be less effective at night. Scientists have previously explored using piezoelectric sensors — self-powered materials that accumulate an electrical charge in response to pressure — for monitoring a driver’s posture, which changes when a person falls asleep, has a sudden health emergency or is intoxicated. However, existing piezoelectric sensors cannot withstand high temperatures, a requirement for electrical and electronic equipment in vehicles. Toshimi Nagase and colleagues wanted to develop flexible, heat-resistant piezoelectric sheet sensors that could be embedded in a vehicle’s seat to monitor the driver’s posture.

The researchers prepared zinc oxide-based films directly on a polyimide surface and then screen-printed a silver paste on both sides to obtain a piezoelectric sheet. They connected a coaxial cable to detect changes in electrical charge with pressure and then folded the sheet in half around the cable. The sensor sheet resisted heating up to 250 F, with no changes in its properties. After showing that the sensor could discriminate changes in mechanical load, the team placed a sensor in the back of a chair. By detecting a seated person’s slight body movements, the sensor allowed the researchers to calculate the person’s respiration and pulse rates. Two other sensors attached to the seat of a chair could sense when a person leaned left or right with their upper body, which could indicate drowsiness.

The researchers say that in the future, a monitoring system based on the sensors might detect changes in vital signs or body posture, triggering a self-driving car to find a safe location and then stop. The vehicle could also contact emergency healthcare providers, depending on the situation. To get to that point, the next step is to test the piezoelectric sensors in a car, where vehicle motions and vibrations will contribute to background noise in the measurements, the team says.

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In 2013, a nearly complete leather scale armor was found in the tomb of an approx. 30-year-old male near the modern-day city of Turfan in Northwest China. This unprecedented find, which survived the millennia thanks to the area’s extremely arid climate, provided the international team led by Patrick Wertmann from the Institute of Asian and Oriental Studies of the University of Zurich with new insights on the spread of military technology during the first millennium BCE.

Scale armors protect the vital organs of fighters like an extra layer of skin without restricting their mobility. The armors were made of small shield-shaped plates arranged in horizontal rows and sewn onto a backing. Due to the costly materials and laborious manufacturing process, armors were very precious, and wearing them was considered a privilege of the elite. It was rare for them to be buried with the owner. However, the emergence of powerful states with large armies in the ancient world led to the development of less precious but nevertheless effective armors made of leather, bronze or iron for ordinary soldiers.

Standard military equipment for horsemen

The researchers used radiocarbon dating to determine the age of the armor to between 786 and 543 BCE. It was originally made of about 5,444 smaller scales and 140 larger scales, which together with leather laces and lining weighed between 4 and 5kg. The armor resembles a waistcoat that protects the front of the torso, hips, the sides and the lower back of the body. It can be put on quickly without the help of another person and fits people of different statures.

“The armor was professionally produced in large numbers,” says Patrick Wertmann. With the increasing use of chariots in Middle Eastern warfare, a special armor for horsemen was developed from the 9th century BCE. These armors later became part of the standardized equipment of military forces of the Neo-Assyrian Empire, which extended from parts of present-day Iraq to Iran, Syria, Turkey and Egypt.

Two armors, distinct units

While there is no direct parallel to the 2,700-year-old armor in the whole of Northwest China, there are some stylistic and functional similarities to a second contemporary armor of unknown origin held by the Metropolitan Museum of Art in New York (the Met). It is possible that the two armors were intended as outfits for distinct units of the same army, i.e. the Yanghai armor for cavalry and the armor in the Met for infantry.

It is unclear whether the Yanghai armor belonged to a foreign soldier working for the Assyrian forces who brought it back home with him, or whether the armor was captured from someone else who had been to the region. “Even though we can’t trace the exact path of the scale armor from Assyria to Northwest China, the find is one of the rare actual proofs of West-East technology transfer across the Eurasian continent during the early first millennium BCE,” says Wertmann.

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