There are hundreds of cases of sharks and fish caught in plastic

New research by scientists at the University of Exeter shows that there are hundreds of sharks and other marine animals including the breeds that have to withstand waste, often plastic, that get stuck in their bodies.

For example, the study considered the case of a mako shark found with a fishing rope wrapped tightly around its back. In this case, the shark had continued to grow and this had caused the rope to dig into his skin damaging its spine.

This waste, which can get caught in the body of fish, especially the larger ones, can cause pain, suffering and even the death of the animal, as noted by Kristian Parton, of the Center for Ecology and Conservation of Exeter, one of the authors of the study.

By reviewing various academic articles and reports on Twitter, the researchers found more than 600 cases of sharks and rays caught in plastic, very often fishing nets, in all the oceans of the world, from the Atlantic to the Pacific via the Indian Ocean.

Most of the objects that ended up entangled in the body of the fish consisted of phantom fishing gear, especially nets. There was no lack of other types of waste such as tire pieces, packaging waste or polyethylene bags.

The study was published in Endangered Species Research.

Largest algae flowering in the world identified

It has already been defined as the largest algae flowering in the world identified by a research group of the University of South Florida. This real “belt” of brown macroalgae of the genus Sargassum was identified last year.

According to the same researchers, more than 20 million tons of this seaweed belt floated on surface waters in the Gulf of Mexico, off the east coast of Florida and in the tropical Atlantic. The related study then appeared the other day in Science.

The researchers performed various analyzes and found that this algae belt is formed seasonally in response to two key events. First of all, because the Amazon during the spring and summer discharges large quantities of nutrients that are excellent for algae into the ocean. This contribution of nutrients is then amplified, according to the researchers, by the increase in deforestation from the use of fertilizers.

This is the hypothesis made by Chuanmin Hu, one of the researchers involved in the study, who also used satellite data collected since 2006 to explain the true invasion of algae of this kind off the coast of the Gulf of Mexico. According to Woody Turner, director of the Ecological Forecasting Program at NASA, the vastness of these algal blooms is so great that one must use satellite images to understand their dynamics over time but also to detect their extension.

If for different marine species greater quantities of algae can mean a greater quantity of food or habitat, for other species quantities of widespread and intricate algae can become real marine prisons where it becomes difficult to move even breathe. This is the case, for example, of corals and seagrasses, other species of marine plants.

Sargassum also releases a number of gases, including hydrogen sulfide, which can become a serious problem for the environment, even for human beings who go to the beaches and who already suffer from respiratory diseases, such as asthma.

Prediabetes inverted in mice by deactivating an enzyme

A group of scientists from the University of Utah states, through a study published in Science, succeeded in reversing the state of pre-diabetes in mice by deactivating an enzyme called dihydroceramide desaturase 1 (DES1).

The deactivation of this enzyme leads to a lowering of the total amount of ceramides, a family of lipid molecules, in the body of mice. DES1 thus becomes a useful target for the possible creation of drugs to prevent the state of pre-diabetes, possibly even in humans. This is a therapeutic strategy that is “extraordinarily effective,” as specified by Scott Summers, one of the authors of the study together with David Kelley.

The same researcher underlines the fact that ceramides play a leading role in metabolism. Among other things, the same researchers have discovered that the ceramides trigger in the body a series of mechanisms to conserve fat in the cells but in the long run it can cause a reduced capacity of the same cells to synthesize the glucose and to withdraw them from the bloodstream.

Furthermore, the same ceramides cause an increase in the conservation of fatty acids in the liver, slowing down the turnover. This can be an advantage in the short term or when food is scarce but if the latter is abundant the cells begin to store a lot of fat because they increase the levels of ceramides, which happens in obesity. This condition then leads to insulin resistance and fatty liver disease, as well as to prediabetes.

Scientists control sight of a mouse by manipulating neurons of the visual cortex

A group of scientists from Columbia University manipulated the visual cortex of a mouse’s brain to control its visual system. This is the first time that the visual behavior of an animal is controlled by manipulating its neurons.

The researchers specifically manipulated neuronal groups using new optical and analytical tools. They first identified cortical sets that performed certain visual tasks in mice by injecting viruses into their brains that enabled them to analyze neuronal activity.

They then trained rodents to associate a certain visual stimulus to water and in this way every time a certain image appeared, the mice ingested water. Then, through high-resolution optogenetics, they identified the neurons involved in this process of vision and reaction with cellular level precision, which allowed them to be able to reactivate these neurons at will using a two-photon laser.

When you reactivated those precise neurons, the mice activated themselves to drink water even though they had not seen the image that was the input. They therefore basically took control of the visual system of the mice, almost creating an image in their brain to which they responded by ingesting the water.

“It’s the most exciting work in my lab for decades,” says Rafael Yuste, a professor of biological sciences at Columbia and senior author of the study.

Naturally the thought goes immediately to possible applications of such a method on human beings: although the researchers are still far from this, Luis Carrillo-Reid, another author of the study, admits that this research could prove useful for possible attempts at precise reprogramming of the brain, something that would make a huge leap forward for all neuroscience.

Two new species of parasitic wasps of Tibet classified in China

Two new species of parasitic wasps that live at an altitude of over 3400 meters in the Tibetan mountains have been described in an article published in ZooKeys.

The two new classifications were possible thanks to the study of two species originally collected in 2013 and preserved at the Insects Institute of the University of Agriculture and Fujianulture of Fujian, China.

The two species belong to the genus of the microplites, a genus belonging to the microgastrinae family. This family is composed of small parasitic wasps, black or brown: in fact, the eggs develop in the larvae of moths or butterflies.

Unlike other pests, in this case the larvae that host these small wasps continue to live until then the wasp eggs hatch. At that point, the small wasps begin to devour the organs of the host larvae assimilating all the body fluids and killing them.

The two new species of wasps, called Microplitis paizhensis and Microplitis bomiensis (the names of the species refer to the places where they were collected) populate grasslands and bushes at an altitude of more than 3400 meters in the area of ​​Tibet, something quite unusual for the microplite wasps.

Intermittent fasting diet can prevent diabetes

The intermittent fasting diet is already known because it can improve insulin sensitivity and because it protects from fatty liver. Now a new study conducted by the Deutsches Zentrum fuer Diabetesforschung (DZD) of the German Institute of Human Nutrition (DIFE), Germany, reveals that it can also help keep pancreatic fat levels low, as they saw in experiments performed on mice.

In fact, Annette Schürmann and Tim J. Schulz found that overweight mice with a predisposition to diabetes present an extraordinary accumulation of fat cells inside the pancreas. The researchers initially divided the mice into two groups: the rodents of the first group could eat as much as they wanted whenever they wanted. The second group was instead placed in an intermittent fasting regime on the basis of which they received unlimited portions one day and nothing the next day.

After five weeks of experimentation, the researchers observed differences in the pancreas of mice. Fat cells accumulated in the pancreas of group 1 mice whereas group 2 mice had very few deposits in this organ. Then analyzing the pancreatic adipocytes of the mice, the researchers discovered “that the increase in insulin secretion causes the islands of Langerhans of animals at risk of diabetes to run out faster and, after a while, to completely cease functioning,” as reported by Schürmann.

The study therefore suggests that it is necessary to limit fat not only in the liver, but also in the pancreas to prevent type 2 diabetes, and to limit the fat in the pancreas it could be very useful to carry on a diet that involves intermittent fasting.

It is a diet that is fairly easy to follow, non-invasive and that above all does not require drugs.

Corn-based diet may have contributed to the extinction of the Maya

The tightly corn-based diet may have contributed to the extinction of the Maya according to a new study published in Current Anthropology. According to the researchers, in fact, the strong dependence on the maize crop by the Maya would have made this population so vulnerable to drought events and in general to climate change as to be one of the main reasons why it has disappeared.

The only cause would not result, but one of the linked causes, together with the expansion of the population and in general the degradation of the environment caused by agricultural intensification, as pointed out by Claire Ebert, one of the authors of the study together with Julie Hoggarth, Jaime Awe, Brendan Culleton and Douglas Kennett.

The researchers analyzed the remains of 50 human burials of a Mayan community that once lived near today’s Cahal Pech in Belize. With the radiocarbon dating technique, the researchers determined the age of these burials and discovered that they date back to a period between 735-400 BC and 800-850 AD.

Later they analyzed the remains of bone collagen to understand what they ate and how their diets changed over the years. They found an ever-increasing consumption of corn and a more varied consumption, which included various wild and animal plants, in the oldest bodies.

This means that the most ancient populations were better able to withstand droughts and unfavorable climatic events compared to the more recent populations, more dependent on corn, a plant that needs much more water and is not very tolerant of drought.