Monthly Archives: June 2020

Asian tiger mosquito, native to warm climate is now gaining ground in Illinois’s harsh winter

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Researchers report that the Asian tiger mosquito, Aedes albopictus, has become more abundant across Illinois in the last three decades, spreading diseases such as chikungunya or dengue fever, largely confined to Asian warm climate, especially the forests of southeast Asia.

Ever since it found its way to Texas around 1985, it has quickly spread to Illinois, despite its harsh winters, said researchers. “The global trade in used tires facilitates the spread of the mosquito,” said Chris Stone, a medical  the entomologist at the Illinois Natural History Survey and the lead author of the new study. “The eggs get stuck to the walls of the tires and can survive even in dry conditions. Tires are also great at retaining rainwater, which is perfect for the larvae to develop in.”

Stone and his colleagues studied how the mosquitoes were able to spread across Illinois, given how cold the state’s winters can be. In their paper published in the Journal of Medical Entomology, they said the spread of the Asian tiger mosquito in Illinois also is a result of repeated introductions from neighboring counties.

Genetic info to track spread

Rebecca Smith, a professor of pathobiology at the University of Illinois at Urbana-Champaign who led the research with Stone said, “Winters are fairly warm in cities like Chicago because of all the roads and concrete. There are a lot of places like sewers and subways where these mosquitoes can live in the winter.”

The researchers used genetic information to track the spread of the mosquitoes, focusing on mitochondrial DNA, which is abundant in cells. Comparing mitochondrial DNA sequences is an established method for studying the spread of mosquitoes globally.

“We found that there is a surprising diversity of Aedes albopictus in Illinois,” Stone said. “Some were from the Texas population, but a few had previously been found only in Japan. This observation supports the idea that we see multiple introductions of these mosquitoes from different places.”

Asian tiger mosquitoes are good at outcompeting other mosquitoes, which can have both beneficial and harmful effects. Some studies from Florida and Texas where Aedes albopictus has displaced Aedes aegypti, a closely related mosquito known as the yellow fever mosquito that can transmit dengue and yellow fever, prompted the team to focus on the implications of the establishment of the Asian tiger mosquito in Illinois on other mosquito species.

 

 

 

Mice shrinking in size? Not just climate or urban impact but more to it, says study

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According to the controversial Bergmann’s Rule, species tend to be larger in cold climates and smaller in warm ones, which may shrink mice for an instance over a period of time, while humans facing the same prospect is not ruled out.

A new study tested this and published a paper in Scientific Reports, after analyzing 70 years of records of the North American deer mouse, Peromyscus maniculatus, arguably the most common and best-documented mammal in the U.S.

Unexpectedly, researchers found deer mice are generally decreasing in mass over time, but this trend may not be linked to changes in climate, say the scientists but they are surprised to find larger-bodied deer mouse populations getting smaller and smaller-bodied populations are getting larger.

No climate impact

“The most exciting aspect of this study was one that still remains mysterious – deer mice appear to be getting smaller over time, but it doesn’t seem to directly relate to climatic drivers or urbanization,” said co-author Robert Guralnick, curator of bioinformatics at the Florida Museum of Natural History. “Is this generally true for mammals?”

Body size is an important physical characteristic in warm-blooded animals because it helps maintain the right body temperature and for metabolism and heat transfer. “Even in a small mammal like this, a minor change in body mass could have really important consequences for optimizing those energy balances,” said study co-author Bryan McLean, assistant professor at the University of North Carolina Greensboro and a former postdoctoral researcher at the Florida Museum.

Larger-bodied animals have less body surface – which releases heat – relative to the volume of their bodies, so they may cope with the cold better than their smaller-bodied kin, says the thermodynamic foundation of Bergmann’s Rule. Because body size affects thermoregulation, changes in body size could influence animals’ resilience to climate change.

Sources of study

To examine changes in the deer mouse’s body size in relation to space, time, climate and human population density, Guralnick and his collaborators compiled body length and mass measurements taken by thousands of researchers across the U.S. over seven decades.

Their findings show that deer mice in colder climates tend to be longer and have bigger body mass, consistent with Bergmann’s Rule. As temperature changed over a period, deer mice body mass decreased, which also aligned with the researchers’ hypothesis. As precipitation increased, however, researchers expected an increase in mouse body but they found body mass also decreased.

According to Bergmann’s Rule, mice should be smaller in urban areas to beat the heat but due to huge food and garbage available in cities, mice could grow larger. The data showed that in urban areas, deer mice populations tended to retain the same body mass, but grow shorter in length.

When the team decoupled mouse mass from all of these factors, they still noted a general decrease in mass, hinting that climate and urbanization influence body size in a more complicated way than previously thought.

“Preliminarily, this is very intriguing, but we still don’t know what drives this decrease in mass,” Guralnick said. The team will now turn its attention to analyzing body size across all mammals, he said.

 

Internet for All? SpaceX just launched 60 satellites into space orbit, as part of its Starlink fleet

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On Wednesday, June 3 at 9:25 p.m. EDT, SpaceX launched its eighth Starlink mission aboard Falcon 9, which lifted off from Space Launch Complex 40 (SLC-40) at Cape Canaveral Air Force Station, just days after SpaceX and NASA made history amid coronavirus pandemic last weekend, launching two astronauts into space on board a Falcon 9 rocket to join the International Space Station (ISS).

Astronauts Robert Behnken and Douglas Hurley were launched into space on board a SpaceX Falcon 9 rocket, marking the first time humans have been launched from the US since 2011.

Falcon 9’s first stage previously supported the Telstar 18 VANTAGE mission in September 2018, the Iridium-8 mission in January 2019, and two separate Starlink missions in May 2019 and in January 2020. Following stage separation, SpaceX landed Falcon 9’s first stage on the “Just Read the Instructions” droneship, which was stationed in the Atlantic Ocean.

On this mission, SpaceX launched the first Starlink satellite with a deployable visor to block sunlight from hitting the brightest spots of the spacecraft. NASA’s Kennedy Space Centre said: “The goal of Starlink is to create a network that will help provide internet services to those who are not yet connected, and to provide reliable and affordable internet across the globe.”

Starlink Satellite

Explaining the Starlink satellite design, SpaceX said on its website that it was driven by the fact that they fly at a very low altitude compared to other commmunication satellites. “We do this to prioritize space traffic safety and to minimize the latency of the signal between the satellite and the users who are getting internet service from it. Because of the low altitude, drag is a major factor in the design.”

During orbit raise, the satellites must minimize their cross-sectional area relative to the wind, otherwise drag will cause them to fall out of orbit. High drag is a double-edged sword—it means that flying the satellites is tricky, but it also means that any satellites that are experiencing problems will de-orbit quickly and safely burn up in the atmosphere. This reduces the amount of orbital debris or “space junk” in orbit.

This low-drag and thrusting flight configuration resembles an open book, where the solar array is laid out flat in front of the vehicle. When Starlink satellites are orbit raising, they roll to a limited extent about the velocity vector for power generation, always keeping the cross sectional area minimized while keeping the antennas facing Earth enough to stay in contact with the ground stations, said SpaceX.

Shark-Fin orientation

When the satellites reach their operational orbit of 550 km, drag is still a factor—so any inoperable satellite will quickly decay—but the altitude control system is able to overcome this drag with the solar array raised above the satellite in a vertical orientation that we call “shark-fin.” This is the orientation in which the satellite spends the majority of its operational life.

A recent study, published in arXiv, researchers led by Stefano Gallozzi, wrote: “Depending on their altitude and surface reflectivity, their contribution to the sky brightness is not negligible for professional ground based observations. With the huge amount of about 50,000 new artificial satellites for telecommunications planned to be launched in Medium and Low Earth Orbit, the mean density of artificial objects will be of >1 satellite for square sky degree; this will inevitably harm professional astronomical images.”

Italian team develops superior AI model for stock trading

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Using the science of convolutional neural networks (CNNs) with deep learning – a discipline within artificial intelligence, Italian researchers have developed a system of market forecasting with the potential for greater gains and fewer losses than previous attempts to use AI methods to manage stock portfolios.

The team, led by Prof. Silvio Barra t the University of Cagliari, published its findings in IEEE/CAA Journal of Automatica Sinica. The University of Cagliari-based team set out to create an AI-managed “buy and hold” (B&H) strategy – a system of deciding whether to take one of three possible actions – a long action (buying a stock and selling it before the market closes), a short action (selling a stock, then buying it back before the market closes), and a hold (deciding not to invest in a stock that day).

At the heart of their proposed system is an automated cycle of analyzing layered images generated from current and past market data unlike the older B&H systems, based on machine learning, a discipline that leans heavily on predictions based on past performance.

Just like seasoned investor

By letting their proposed network analyze current data layered over past data, they are able to take market forecasting a step further, allowing for a type of learning that more closely mirrors the intuition of a seasoned investor rather than a robot. Their proposed network can adjust its buy/sell thresholds based on what is happening both in real time and the past. Taking into account present-day factors increases the yield over both random guessing and trading algorithms not capable of real-time learning, they said.

To train their CNN for the experiment, the research team used S&P 500 data from 2009 to 2016. The S&P 500 is widely regarded as a litmus test for the health of the overall global market.

At first, their proposed trading system predicted the market with about 50 percent accuracy, or about accurate enough to break even in a real-world situation. They discovered that short-term outliers, which unexpectedly over- or underperformed, generating a factor they called “randomness.” Realizing this, they added threshold controls, which ended up greatly stabilizing their method.

“The mitigation of randomness yields two simple, but significant consequences,” Prof. Barra said. “When we lose, we tend to lose very little, and when we win, we tend to win considerably.” Howwever, further enhancements will be needed, said Prof. Barra, as other methods of automated trading already in use make markets more and more difficult to predict.

Why Indian-Americans in US have fewer infant sudden deaths? Study Finds Reason

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Indian-American parents have the highest percentage of sleeping with their babies among ethnic groups in New Jersey but the lowest rate of sudden unexpected infant death (SUID), found a study recently.

Researchers from the Rutgers Biomedical and Health Sciences attributed this paradoxical finding to a variety of compensatory factors, including Indian-Americans’ practice of placing their infants on their backs to sleep. The study was published in the journal New Jersey Pediatrics.

“Conditions that substantially increase the risk of SUID while bed-sharing include smoking, alcohol use and maternal fatigue,” said lead author Barbara Ostfeld, a professor of pediatrics at Rutgers Robert Wood Johnson Medical School. “Indian-Americans smoke and use alcohol less than other populations. In addition, grandparents tend to be very active in childcare, which reduces maternal fatigue. Apart from bed-sharing, poverty also increases the risk of SUID, and Indian-Americans have higher incomes.”

The American Academy of Pediatrics considers bed-sharing to be a high risk factor in SUID, which includes sudden infant death syndrome, accidental suffocation and strangulation in bed, and ill-defined and unknown causes in children under one year old.

“There is strong clinical information on the risks associated with bed-sharing,” Ostfeld said. “Our intent was to discover more about this little-researched demographic breakdown, so we can better understand the risk factors for SUID in all groups and create culturally sensitive health messaging.”

The researchers looked at the mortality rates of 83,000 New Jersey-born infants of Asian-Indian heritage over a 15-year period and safe sleep practices in a sampling of this population. Results showed that 97 percent of the surveyed American-born mothers of Asian-Indian heritage reported using a crib, compared to 69 percent of those who were foreign-born.

Although infants of the foreign-born mothers now residing in the United States had a higher SUID rate compared to infants of U.S.-born mothers of Asian-Indian heritage, for whom no SUID was recorded, the rate was still lower than that of other populations: From 2000 to 2015, infants of foreign-born mothers of Asian-Indian heritage had a SUID rate of 0.14 deaths per 1,000 live births, compared to 0.4 in white, 0.5 in Hispanic and 1.6 in black populations.

“Our study shows that improved compliance with American Academy of Pediatrics guidelines on supine sleep and avoiding bed-sharing is associated with a lower rate of SUID even in already low-risk groups,” said Ostfeld. “Larger studies are needed to better understand the complex variables that affect risk in sharing a bed with an infant.”

Patient ID, medical records’ matching now helps during vaccination, say experts

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Experts from Regenstrief Institute, Mayo Clinic and the Pew Charitable Trusts have suggested that matching patient records from disparate sources has become crucial to stem the tide of the current coronavirus pandemic and allow for fast action for future outbreaks of highly contagious viruses.

In a peer-reviewed commentary published in npj Digital Medicine, the team of experts said rapid identification of COVID-19 infected and at-risk individuals and the success of future large-scale vaccination efforts in the United States will depend on how effectively an individual’s electronic health data is securely preserved and shared among healthcare providers, including hospitals and pharmacies, and other systems used to track the illness and immunization.

For data sharing to be effective, electronic health records (EHRs) — both those held within a single facility and those in different healthcare organizations — must correctly refer to a specific individual.

Some of the specimen queries are:

Is Billy Jones known at a different doctor’s office as William Jones and are all his health records linked? To which Maria Garcia do lab test results belong?
Which John Smith was referred to during contact tracing?

The commentary note said patient matching rates vary widely, with healthcare facilities failing to link records for the same patient as often as half the time. Authors — Shaun Grannis, vice president for data and analytics at Regenstrief Institute and Regenstrief Professor of Medical Informatics at Indiana University School of Medicine, John D. Halamka, president of Mayo Clinic Platform and Ben Moscovitch, director of the Pew Charitable Trusts’ health information technology initiative — call for stakeholders to urgently address the patient matching conundrum. Otherwise, efforts to curtail the current pandemic and future ones will be ill-advisedly delayed, they cautioned.

“The sharing of more data and use of standards — reflect near-term opportunities that government and health care organizations can implement to respond to the current pandemic and prepare for future ones. In the longer term, there may be other opportunities — such as use of biometrics, unique identifiers, or multi-factor authentication — that could further enhance patient identification and matching, including for routine care,” they said in their note.

However, those options and the associated standards that underlie their success are worthwhile to examine, but cannot be designed, deployed, and implemented in a near-term manner that could help mitigate the effects of this pandemic, said the authors.