Scientists from the Laboratoire d’Hydrodynamique at the Ecole Polytehcnique will explain the physics behind optimal arrow design at the 72nd Annual Meeting of the APS Division of Fluid Dynamics in Seattle on Saturday, November 23, 2019. The presentation is part of a session on biological fluid dynamics in flight. The researchers said the aspect of feather size and shape in archery accuracy has not yet been studied in depth. To discover the optimal feather design, Tom Maddalena, Caroline Cohen, and Christophe Clanet first shot arrows with various feathers using a throwing machine....

The variant hunters are helping us to understand how and why the COVID-19 virus is spreading, allowing us to fight back against the COVID-19 pandemic. Hear from some of the scientists behind the UK’s nationwide sequencing effort to track SARS-CoV-2. Sir Patrick Vallance (the government’s Chief Scientific Adviser) also describes how the expertise that came together during the pandemic is now recognized across the world – and why it’s crucially important to continue to sequence to be ready for future pandemics....

When the Very Large Array was completed forty years ago, it was a different kind of radio telescope. Rather than having a single antenna dish, the VLA has 27. The data these antennas gather is combined in such a way that they act as a single radio telescope. As a radio array, the virtual dish of the VLA can cover an area roughly the size of Disney World. But the VLA can also do something ordinary telescopes can’t do: it can change shape....

When one hears a howl in the forest, the first thing that he associates that sound with is the wolf. And it’s true, howling is a characteristic communication form of wolves, but it is also widespread among canine species. They use it for long-distance communication with others, to mark territory boundaries, and also, to define the position of the other wolves, which in most cases, also reply with howling. Among their domesticated relatives, our best friend the domestic dog, the situation seems a bit more complicated: some breeds, like wolf-like sled dogs, are widely believed to be “hard-howlers,” meaning that they howl frequently, even in ‘reply’ to irrelevant sounds like bells, sirens or music, while others never howl even once during their life, even though they are capable of producing them....

In 2007, Google unleashed a fleet of cars with roof-mounted cameras to provide street-level images of roads around the world. Now MIT spinout Essess is bringing similar “drive-by” innovations to energy efficiency in homes and businesses. The startup deploys cars with thermal-imaging rooftop rigs that create heat maps of thousands of homes and buildings per hour, detecting fixable leaks in “building envelopes” — windows, doors, walls, and foundations — to help owners curb energy loss....

These enormous “rogue” swells have long captured the imagination. Although mathematical modelling has helped scientists and engineers hypothesise different causes, since the 1980’s it was thought they were caused by either wave overlap (the superposition principle) or a mechanism which triggers a rogue wave (modulation instability) in one-directional wave systems. In multi-directional systems, known as crossing wave formations or crossing seas, modulation instability was believed to be inactive, rendering extreme waves rare or impossible in these conditions....

However, new research publishing this week in the leading international journal PNAS, sheds fresh light on the complicated interplay of factors affecting global climate and the carbon cycle — and on what transpired millions of years ago to spark two of the most devastating extinction events in Earth’s history. Using chemical data from ancient mudstone deposits in Wales, an international team involving scientists from Trinity College Dublin discovered that periodic changes in the shape of Earth’s orbit around the Sun were partly responsible for changes in the carbon-cycle and global climate during and in between the Triassic-Jurassic Mass Extinction (around 201 million years ago, when around 80% of the species on Earth disappeared forever) and the Toarcian Oceanic Anoxic Event (around 183 million years ago)....

Among planetary systems, TRAPPIST-1 is of particular interest because seven planets have been detected orbiting this star, a larger number of planets than have been detected in any other exoplanetary system. In addition, all of the TRAPPIST-1 planets are Earth-sized and terrestrial, making them an ideal focus of study for planet formation and potential habitability. Arizona State University (ASU) scientists Cayman Unterborn, Steven Desch, and Alejandro Lorenzo of the School of Earth and Space Exploration, with Natalie Hinkel of Vanderbilt University, have been studying these planets for habitability, specifically related to water composition....

A characteristic of depression is a lack of motivation. Cold Spring Harbor Laboratory (CSHL) Professor Bo Li, in collaboration with CSHL Adjunct Professor Z. Josh Huang, discovered a group of neurons in the mouse brain that influences the animal’s motivation to perform tasks for rewards. Dialing up the activity of these neurons makes a mouse work faster or more vigorously—up to a point. These neurons have a feature that prevents the mouse from becoming addicted to the reward....

The scientists published their findings in the journal Proceedings of the National Academy of Sciences. The merchant ship Relitto del Pozzino sank off the coast of Italy in 130 BCE. Archaeological excavations in 1989 and 1990 yielded glass bowls, amphoras for carrying wine, lamps, tin, and bronze vessels all likely to have originated in the eastern Mediterranean. There were also some artifacts contained in a wooden chest that had rotted away....

Two for one: Repeated seasonal influenza vaccines also provide kids better protection against future flu pandemics, researchers find. Researchers at McMaster University have found that children who receive years of season-specific flu vaccines develop antibodies that also provide broader protection against new strains, including those capable of causing pandemics. The same ability does not exist in adults. The findings, reported today in the journal Cell Reports Medicine, could inform the design of a universal influenza virus vaccine for children, who are especially vulnerable to serious complications from flu, such as pneumonia, dehydration and, in rare cases, death....

The findings suggest that a component of this protein, called viral polymerase, could potentially be added to COVID-19 vaccines to create a longer-lasting immune response and increase protection against new variants of the virus. Most COVID-19 vaccines use part of the spike protein found on the surface of the virus to prompt the immune system to produce antibodies. However, newer variants — such as delta and omicron — carry mutations to the spike protein, which can make them less recognizable to the immune cells and antibodies stimulated by vaccination....

The work could lead to regenerative treatments for patients with critical bone defects and soldiers who have suffered traumatic bone injuries. The findings, published in the journal Science Advances, could also lead to a simple, scalable and inexpensive way to manufacture a pure population of bone-building cells. “One of the broader goals of our research is to make regenerative treatments more accessible and clinically relevant by developing easy, efficient and cost-effective ways to engineer human cells and tissues,” said Shyni Varghese, a bioengineering professor at UC San Diego and senior author of the study....

The UK variant of SARS-CoV-2 spread rapidly in care homes in England in November and December last year, broadly reflecting its spread in the general population, according to a study by UCL researchers. The study, published as a letter in the New England Journal of Medicine, looked at positive PCR tests of care home staff and residents between October and December. It found that, among the samples it had access to, the proportion of infections caused by the new variant rose from 12% in the week beginning November 23 to 60% of positive cases just two weeks later, in the week beginning December 7....

Cities are responsible for almost 1/5th of the global methane emissions caused by human activities. However, most cities don’t capture information about the full range of sources of this powerful greenhouse gas. In 2020, a team led by McGill University, measured methane emissions from various sources across the city of Montreal. The researchers found that two of the four most important sources of methane emissions in the city (historic landfills and manholes) are not included in the city’s municipal greenhouse gas inventories, making it difficult to tackle the problem fully, or reach the city’s goal of being carbon neutral by 2050....

Why do dogs, unlike wolves, make eye contact with people? New research from Yale University helps fill out the evolutionary history of the deep and enduring connection between humans and dogs. Domesticated dogs look at their owners to convey and request a host of information — for instance, for help in solving a difficult problem. Wild wolves do not. Dingoes appear to represent an intermediate point in the domestication of wolves....

Have you ever thought about the motion of your skeleton as you go about your daily activities? X-ray images may come to mind when we think about this question. But how can we measure the motion of a skeleton in a moving animal that interacts with its environment without using x-rays? And why is this important? Studying the freely moving animal can provide unique insights into how animals behave and make decisions, such as avoiding predators, finding mates, and raising their young....

Galaxies are classified into two types depending on their morphology: spirals and ellipticals. Spirals have a lot of cold gas and dust and optically-blue looking spiral arms. An average of one Sun-like star forms per year in spiral galaxies. Elliptical galaxies, on the other hand, are yellow in color and lack distinctive characteristics like spiral arms. It is still a mystery to astronomers why the elliptical galaxies we see today haven’t been producing new stars for billions of years....

Black Americans experienced highest per capita excess death rates, while regional surges contributed to higher excess death rates from COVID-19 and other causes, a VCU-led Journal of the American Medical Association study finds. Extended surges in the South and West in the summer and early winter of 2020 resulted in regional increases in excess death rates, both from COVID-19 and from other causes, a 50-state analysis of excess death trends has found....

Dealing with a global pandemic has taken a toll on the mental health of millions of people. A team of MIT and Harvard University researchers has shown that they can measure those effects by analyzing the language that people use to express their anxiety online. Using machine learning to analyze the text of more than 800,000 Reddit posts, the researchers were able to identify changes in the tone and content of language that people used as the first wave of the COVID-19 pandemic progressed, from January to April of 2020....