Male spiders use catapult mechanism to avoid sexual cannibalism

Close-up of communal orb-weaving spiders mating.
Photo credit: Shichang Zhang

In the animal word, numerous mechanisms have been described that allow for extremely fast actions or reactions via the slow storage of energy, typically in elastic structures which is then nearly instantly released, similar to the operation of a catapult. Many of these mechanisms are employed for prey capture or predator avoidance, however such superfast actions have not yet been reported as a means to dodge sexual mechanism.

Associate Professor Li Daiqin from the National University of Singapore (NUS) and a team of scientists have discovered a mechanism in the legs of male spiders enabling them to undertake a split-second catapult action immediately after mating to avoid being cannibalized by their partner. This is the first time a catapult mechanism to escape sexual cannibalism has been observed in any animal.

The scientists demonstrated that male communal orb-weaving spiders (Philoponella prominens (Family: Uloboridae)) activate the catapult mechanism by extending a joint that lacks extensor muscles, called the tibia-metatarsus, on their forelegs via hydraulic pressure. The rapid expansion of the legs greatly reduces the likelihood of the male being sexually cannibalized.

Some Volcanoes Might Warm Climate, Destroy Ozone Layer

A new NASA climate simulation suggests that extremely large volcanic eruptions called “flood basalt eruptions” might significantly warm Earth’s climate and devastate the ozone layer that shields life from the Sun’s ultraviolet radiation.

The result contradicts previous studies indicating these volcanoes cool the climate. It also suggests that while extensive flood-basalt eruptions on Mars and Venus may have helped warm their climates, they could have doomed the long-term habitability of these worlds by contributing to water loss.

Source/Credit:
Video: NASA/Goddard Space Flight Center
Final Editing and Conversion: Scientific Frontline
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Squid and Octopus Genome Studies Reveal How Cephalopods’ Unique Traits Evolved

The Hawaiian bobtail squid (Euprymna scolopes) is a model system for studying animal-bacterial symbiosis.
Credit: Tom Kleindinst

Squid, octopus, and cuttlefish – even to scientists who study them – are wonderfully weird creatures. Known as the soft-bodied or coleoid cephalopods, they have the largest nervous system of any invertebrate, complex behaviors such as instantaneous camouflage, arms studded with dexterous suckers, and other evolutionarily unique traits.

Now, scientists have dug into the cephalopod genome to understand how these unusual animals came to be. Along the way, they discovered cephalopod genomes are as weird as the animals are. Scientists from the Marine Biological Laboratory (MBL) in Woods Hole, the University of Vienna, the University of Chicago, the Okinawa Institute of Science and Technology and the University of California, Berkeley, reported their findings in two new studies in Nature Communications.

“Large and elaborate brains have evolved a couple of times,” said co-lead author Caroline Albertin, Hibbitt Fellow at the MBL. “One famous example is the vertebrates. The other is the soft-bodied cephalopods, which serve as a separate example for how a large and complicated nervous system can be put together. By understanding the cephalopod genome, we can gain insight into the genes that are important in setting up the nervous system, as well as into neuronal function.”

In Albertin et al., published this week, the team analyzed and compared the genomes of three cephalopod species – two squids (Doryteuthis pealeii and Euprymna scolopes) and an octopus (Octopus bimaculoides).

Only 10 vaquita porpoises survive, but species may not be doomed

Credit: Paula Olson/NOAA

The vaquita porpoise, the world’s smallest marine mammal, is on the brink of extinction, with 10 or fewer still living in Mexico’s Gulf of California, their sole habitat. But a genetic analysis by a team of UCLA biologists and colleagues has found that the critically endangered species remains relatively healthy and can potentially survive — if illegal “gillnet” fishing ceases promptly.

“Interestingly, we found the vaquita is not doomed by genetic factors, like harmful mutations, that tend to affect many other species whose gene pool has diminished to a similar point,” said Christopher Kyriazis, a UCLA doctoral student in ecology and evolutionary biology and a co–lead author of the research. “Outlawed fishing remains their biggest threat.”

The small porpoises, which range from 4 to 5 feet in length, often become entangled and die in the large mesh gillnets used by poachers hunting the totoaba, an endangered fish highly valued in some countries for its perceived medicinal properties. While Mexico has outlawed totoaba fishing and made the use of these nets in the vaquitas’ habitat illegal, many say the bans are not always enforced.

The researchers analyzed the genomes of 20 vaquitas that lived between 1985 and 2017 and conducted computational simulations to predict the species’ extinction risk over the next 50 years. They concluded that if gillnet fishing ends immediately, the vaquita has a very high chance of recovery, even with inbreeding. If, however, the practice continues, even moderately, the prospects of recovery are less optimistic.

Children could find it easier to reach a healthier weight if their parents are addressing their own weight

New research presented at the European Congress on Obesity (ECO) in Maastricht, the Netherlands (4-7 May), has found that many parents attending commercial weight management programs would be happy for their child, if overweight, to also receive support to reach a healthier weight.

The latest figures show that 14.4 per cent of children aged four to five in England and 25.5 per cent of ten to 11-year-olds are living with obesity. Obesity rates in both groups increased by around 4.5 percentage points1 between 2019-20 and 2020-21 – the highest annual rise since the National Child Measurement Program (NCMP) began.

Some local authorities in England run free weight management programs for children. Children can be referred to by their GP, other health professionals, the school, the NCMP or by self-referral, depending on where they live.

These programs, however, are not available in all parts of England, and struggle to recruit, engage and retain members, as well as achieve a clinically significant improvement in weight status.

Dr Mears, a Clinical Research Fellow at the University of Bristol's Centre for Academic Primary Care, said: “We know that parents living with obesity are more likely to have children with obesity and so we decided to look at whether it would be feasible to recruit children through parents attending commercial weight management classes.

“We also decided to focus on this group because we felt that the point at which a parent decides to take steps to reach a healthier weight for themselves might represent a good opportunity to address weight concerns in any other members of the family.

“If the whole family make changes together to reach or maintain a healthier weight, this may be more effective than one family member tackling their weight alone.”

To find out more, Dr Mears and colleagues ran an online survey for Slimming World members.

Copper works effectively against Sars-Cov-2 on surfaces - silver does not

The material that makes up a surface influences how long viruses and bacteria can remain contagious on it.
Credit: RUB, Marquard

Silver and copper ions kill many pathogens. For example, implants or medical instruments are coated with these metals. Researchers from Molecular and Medical Virology and Materials Research at the Ruhr University Bochum (RUB) have worked with the surgical research of the BG to determine whether they can help curb the Covid 19 pandemic by rendering Sars-Cov-2 harmless. University Hospital Bergmannsheil Bochum examined. They could show that a copper coating eliminates the virus. But this does not apply to silver. The team reports in the journal Scientific Reports May 2022.

Unedler material sacrifices itself

Copper and silver release positively charged ions to their environment through corrosion, which are harmful to bacteria in various ways and prevent their growth or completely kill them. This effect has long been used, for example by coating implants with these metals in order to avoid bacterial infections. Tricks can be used to ensure that even more ions become free and increase this effect. So, the team around materials researcher Prof. Dr. Alfred Ludwig a so-called sputtering system, with which the thinnest layers or tiny nanofleaks of the metals can be applied to a carrier material. Depending on the order or quantity in which the individual metals are applied, different surface conditions arise. If you also apply a precious metal such as platinum, silver corrodes even faster and releases more antibacterial ions. "In the presence of a more noble metal, the less noble metal sacrifices itself, so to speak," explains Ludwig the principle of the sacrificial anode. The efficiency of such sacrificial anode systems against bacteria was demonstrated by the team of surgical research led by Prof. Dr. Manfred Köller and Dr. Marina Breisch has already demonstrated and published it many times.

Saving the Mekong River Delta from drowning

Tractor on a paddy field in Mekong Delta, Vietnam 
Credit: Thomas Schoch – www.retas.de / Wikimedia Commons

Southeast Asia’s most productive agricultural region and home to 17 million people could be mostly underwater within a lifetime. Saving the Mekong River Delta requires urgent, concerted action among countries in the region to lessen the impact of upstream dams and better manage water and sediments within the delta, according to an international team of researchers. Their commentary, published in Science, outlines solutions to the region’s dramatic loss of sediment essential to nourishing delta land.

“It's hard to fathom that a landform the size of the Netherlands and with a comparable population might disappear by the end of the century”, said study co-lead author Matt Kondolf, a Professor of Landscape Architecture & Environmental Planning at the University of California, Berkeley.

“The Mekong Delta is truly outstanding in terms of agro-economic value and regional importance for food security and livelihoods,” said study co-lead author Rafael Schmitt, a senior scientist at the Stanford Natural Capital Project. “Without rapid action, the delta and its livelihoods could become victims of global and regional environmental change.”

Earth suffers ‘ocean amnesia’ symptom of global warming

Declining ocean memory (blue) between now and end of the 21st century.
Photo credit: Shi et al. 2022

The world’s ocean is steadily losing its year-to-year memory due to global warming, according to a study published in Science Advances co-authored by a University of Hawaiʻi at Mānoa atmospheric scientist. The research team discovered this by assessing future projections from the latest generation of Earth System Models.

Compared with the fast weather fluctuations of the atmosphere, the slowly varying ocean exhibits strong persistence, or “memory,” meaning the ocean temperature tomorrow is likely to look a lot like it does today, with only slight changes. As a result, ocean memory is often used for predicting ocean conditions.

Across climate models, ocean memory decline was found as a collective response to human-induced warming. As greenhouse-gas concentrations continue to rise, such memory decline will become increasingly evident.

“We discovered this phenomenon by examining the similarity in ocean surface temperature from one year to the next as a simple metric for ocean memory,” said Hui Shi, lead author and researcher at the Farallon Institute in Petaluma, California. “It’s almost as if the ocean is developing amnesia.”

Investigational Mucosal COVID Vaccine Protects Against Disease and Transmission

In animal studies that mimic human exposures, an investigational COVID vaccine designed to be taken orally not only protects the host, but also decreases the airborne spread of the virus to other close contacts.

The study, led by Duke researcher Stephanie N. Langel, Ph.D., medical instructor in the Department of Surgery, demonstrated the potential of a COVID vaccine that works through the mucosal tissue to neutralize the SARS-CoV-2 virus, limiting infections and the spread of active virus in airborne particles.

The findings are published today in the journal Science Translational Medicine.

“Considering most of the world is under-immunized -- and this is especially true of children -- the possibility that a vaccinated person with a breakthrough infection can spread COVID to unimmunized family or community members poses a public health risk,” Langel said. “There would be a substantial benefit to develop vaccines that not only protect against disease, but also reduce transmission to unvaccinated people.”

Langel and colleagues -- including teams from the vaccine developer, Vaxart, and a clinical research non-profit, Lovelace Biomedical Research Institute -- tested a vaccine candidate that uses an adenovirus as a vector to express the spike protein of the SARS-CoV-2 virus. The human vaccine is designed to be taken as a pill.

Tropical Forests Benefit Less from Elevated Atmospheric CO2 Than Thought

Tropical vegetation near Lake Bosumtwi in Ghana.
Photo credit: William Gosling.

The amount of carbon dioxide (CO2) in the Earth’s atmosphere has only a small influence on changes in tropical ecosystems despite evidence of enhanced plant growth under elevated CO2 scenarios in greenhouse experiments, according to a new international study.

That means it’s unlikely that tropical forests will expand in response to rising greenhouse gas levels, an outcome that some had hoped might lead to increased CO2 storage in tropical ecosystems as carbon-rich woody plants replace grasslands, which are less adept at storing CO2.

The study was published May 5 in Science. The research team was made up of scientists from the Netherlands, United Kingdom and United States, including scientists at The University of Texas at Austin.

The researchers analyzed 500,000 years of tropical vegetation change in West Africa and found that CO2 had less of an influence on tropical forest growth than water, wildfires and animal grazing did.

“When you scale up to the landscape scale, the resources available and processes occurring within that landscape are more important than the CO2 fertilization,” said the study’s lead author, William Gosling of the Institute for Biodiversity and Ecosystem Dynamics at the University of Amsterdam.