Tropical storms make spiders more aggressive

A group of researchers has discovered that tropical storms make spiders more aggressive. Researchers Jonathan Pruitt and Alexander Little from the University of California at Santa Barbara have analyzed the effects of the tropical storm Florence that struck North Carolina and that of the south and the east coast of the United States. They discovered that the most aggressive spiders had survived the storm, compared to the more “docile” ones, and this caused an evolutionary push which in turn led to colonies of more daring, aggressive and courageous spiders.

This is one of the few studies that analyzes the effects of hurricanes and tropical storms not on humans but on wildlife.

The researchers have in particular analyzed the Anelosimus studiosus, a species of spider that is already known because it is characterized by aggressive or docile behavior. The most aggressive specimens attack the prey very quickly and in large numbers while the most docile specimens spend a greater number of hours in the den.

These are behaviors that evidently on an evolutionary level are increasingly corroborating and diversifying, from one generation to another. The researchers thought that tropical storms and heavy rain combined with very strong winds could be the basis of this behavioral diversification.

Visiting 240 insect colonies in seven states, from Carolina to Florida to pass through Louisiana, they collected various data “measuring” the aggressiveness of spiders near their burrows. Comparing this data with the steps of tropical storms or cyclones, they found that the regions with a greater number of these atmospheric phenomena saw the presence of more aggressive spider colonies.

According to the researchers, that is to say in the fact that the colonies with specimens with more aggressive genetic traits are, for reasons not yet known, more suitable to survive these atmospheric phenomena and these aggressive traits passed from generation to generation to a greater extent than the traits transmitted by the most “docile” spiders who evidently cannot survive in equal numbers.

The study was published in Nature Ecology & Evolution.

Steam balloons could be used to transport rockets and satellites into space

Balls to launch satellites into orbit: this is the strange idea that has come to a group of researchers from the Finnish meteorological institute led by Pekka Janhunen.

These are steam-powered “hot-air balloons” that could carry rockets complete with satellites at high altitude. Given that in this layer of the atmosphere the air is thinner, throwing the above rockets and satellites in orbit around the Earth from this position is much easier and less expensive. Furthermore, the same balls could be reused because they were designed to return to the ground.

This is not an absolutely new idea: similar tests have already been carried out using hydrogen or helium balloons. However these techniques have shown their disadvantages: helium is very expensive while hydrogen is dangerous because it is flammable.

To explain the new technology with steam-powered balloons is the same Janhunen in the statement published on the site of the same Finnish meteorological institute: “The balloon is filled with hot steam on the ground and released. As the balloon rises, part of the water vapor condenses. Condensation releases a lot of latent heat, which slows down the cooling and helps keep the remaining vapor in the gaseous state. After reaching a sufficiently high altitude, the rocket is released, lights up and flies into space. The balloon is emptied of steam, goes down and can be collected for reuse.”

The same researchers calculate that the weight of the rocket transported could even be 10 tons while the satellite that could carry could weigh even hundreds of kilograms.

The design study appeared on arXiv and was conducted by Pekka Janhunen, Petri Toivanen, Kimmo Ruosteenoja.

Biosensor detects salmonella in food

A biosensor that relatively quickly detects even small amounts of salmonella in food has been developed by a group of researchers at the University of Missouri. This is a device designed especially for food producers to identify traces of salmonella in the most efficient way possible.

Currently, the tests that are used to understand if there is salmonella in food go back to cooking samples or extracting DNA to understand the presence of pathogens. These methods are accurate but unfortunately, they lose a lot of time (from one to five days), as pointed out by Mahmoud Almasri, professor of electrical and computer engineering at the College of Engineering of the aforementioned university, as well as one of the authors of the study.

The impedance-based microfluidic biosensor uses a specific fluid that can be mixed with food to detect the presence of salmonella bacteria, primarily those of salmonella B and D, both in raw foods and ready-to-eat foods. In a few hours, the duration of a worker’s shift, as is also emphasized in the press release, it is possible to know the presence of harmful bacteria.

“Our device will allow us to monitor and verify that food products are safe for consumers and to reduce the amount of food recalls that occur,” says Shuping Zhang, a professor at the Veterinary Medical Diagnostic Laboratory of the American University and another author of the study.

Duckweed may be the food of the future

Duckweed, considered one of the fastest-growing plants in the world, could represent one of the key solutions to fight hunger in the world, especially in the coming decades as it is expected that the world population should reach a peak of 9.7 billion people in 2050.

Duckweed is an aquatic plant that reproduces very quickly so that often the freshwater mirrors in which it grows can be completely covered by a carpet of leaves. It is mainly used to produce starch which in turn can be used for the production of ethanol. However, it represents a source of traditional and primary food for different populations living in south-east Asia.

According to Eric Lam, a professor in the Plant Biology Department of Rutgers University-New Brunswick, this small plant, relatively easy to grow, could be the solution. It is more nutritious than salad, has an excellent content of vitamin fibers and offers different nutritional benefits so that some species (the family includes 37) are also used in traditional folk medicine in various regions of Southeast Asia.

It tastes not very strong and chopped or smoothed it can be mixed with other ingredients. Lam himself claims to have tried it also in a sandwich with a hamburger. The same researcher has calculated that the variety of lentils of water that grows faster can produce up to 20 grams (once it has been dried) per square meter every day, a quantity 50 times higher than what can be obtained from corn.

The same seedling, not being very large, can also be cultivated at home or in small gardens with very limited extensions. The same researchers in Lam’s laboratory are trying to maximize culture techniques even further and are also working on automated harvesting methods to reduce reproduction costs even further.

In 20 years these little seedlings, which are almost unknown here in the West, could be one of the typical dishes or side dishes on our tables.

How many Earth-like planets exist? Scientists calculate probabilities

A study published in the Astronomical Journal focused on calculating the probability of the existence of Earth-like planets not only with regard to the size and type of planet but also as regards its distance from the star.

Knowing more precisely the level of this frequency could help to make future observations more profitable, in particular those that will be carried out with future space telescopes, and in general for the search for planets in the habitable zone and therefore also for extraterrestrial life.

The research group, led by Eric B. Ford, professor of astrophysics and astronomy at Pennsylvania State University, used the substantial data set collected over the years by the Kepler space telescope. The main difficulty that the researchers had to overcome, however, lay in the method that Kepler himself used over the years to identify the planets, ie the transit method.

This method makes it easier to find the larger planets closer to the star, but the data is not very useful for finding the smallest and most distant planets. This is precisely why researchers have designed a new study method that simulates universes of stars and planets and then “observes” these simulated universes to determine the number of planets that Kepler would have discovered in each simulated universe.

Danley Hsu, the first author of the study and a student at Penn State, also explains this: “We used the final catalog of the planets identified by Kepler and improved the stellar properties of the European Space Agency’s Gaia spacecraft to build our simulations. Comparing the results with the planets cataloged by Kepler, we have characterized the rate of planets per star and how this depends on the size of the planet and the orbital distance. Our new approach allowed the team to explain several effects that had not been included in previous studies.”

Based on the data, they were able to perform a statistical analysis to estimate the rate of terrestrial-sized exoplanets in the habitable zone around Sun-like stars. The results they obtained seem to show that planets very close to the Earth, from three quarters to one and a half times the size of the Earth, with orbital periods ranging from 237 to 500 days exist around one star every six.

“Knowing how often we should expect to find planets of a certain size and a given orbital period is extremely useful for optimizing exoplanet surveys and designing upcoming space missions to maximize their chances of success,” says Ford.

New discovery could make rice more resistant to serious illness

The discovery made by a group of researchers from Japan and the United Kingdom could prove to be an advantage for rice crops. In their study, published in the Journal of Biological Chemistry, genetic techniques are described to counteract Magnaporthe oryzae, a species of fungus that makes the rice plant sick.

This is a very serious disease that can cause serious losses in terms of rice harvesting (it is believed that one-third of the total rice harvest is currently lost due to this fungus). The various strategies used to counteract this parasitic fungus have not proved to be very sustainable in terms of costs and the environment.

Even attempts to produce new varieties of rice to withstand this fungus more have led to undesirable genetic effects. Today’s new genetic modification technologies can be used “to accurately insert genes into rice plants,” a technique that could overcome the problem of binding drag, a phenomenon during which unwanted genes are transferred along with those desired during the production of other plant varieties.

However, we must first identify the most effective genes that increase the immunity of rice to this disease. This is what the researchers did behind this study: according to them a particular immune receptor in rice could improve resistance to fungal disease in rice by triggering important monetary reactions in response to two distinct fungus proteins. The genes encoding this receptor could then be used to design new rice plants that more effectively counteract fungal proteins.

Very thin thermal nanoscale made with graphene to counteract heat in electrical devices

One of the main problems with electrical devices is that they generate a lot of heat. This defect also involves electric devices equipped with batteries, in fact in these cases it is perhaps even more serious given that a higher level of heat can contribute not only to malfunctions of the device but also to damage the battery, leading in some cases, as in the batteries to lithium, at an explosion risk.

Precisely for this reason, various materials are used, such as glass or plastic, to isolate the electrical components that generate more heat, first of all microprocessors.

A group of Stanford researchers has created a new insulating barrier made from very thin materials that can be stacked like sheets of paper right at the hottest points of electronic devices and that provide the same type of insulation as a 100 times thicker glass plate.

The study, published in Science Advances, describes these thermal nanoscale made of materials as thin as an atom. They are made from a layer of graphene and three other materials structured to resemble very thin sheets, each with a thickness of three atoms. A four-layer insulating barrier is thus created that is only 10 atoms deep and is able to dampen the heat vibrations at the atomic level. The same heat loses most of its energy as it passes through each layer.

“We adapted this idea by creating an insulator that uses several layers of atomically thin materials instead of a thick mass of glass,” says Sam Vaziri, lead author of the study. Now the same researchers are looking for a method to deposit these very thin layers on electronic components during the production of the latter.

In any case, as reported in the press release, the long-term goal of the scientists themselves is to be able to one day control the vibrational energy within the materials as electricity or light is now controlled, something that seems increasingly possible given the great advances in heat-related research in solid objects made in recent years.