Researchers study the strange parental behavior of American coots

An interesting behavior, in relation to the care of offspring by the American coot, was discovered by a team of researchers at the University of California at Santa Cruz. The American coot is a waterbird with grey or black feathers and a white beak that mostly frequents the wetlands of North America. Unlike their parents, the chicks have very brightly coloured feathers and beaks between red and orange.

This difference had already been noted by previous studies and, again, other studies had shown that the parents seem to prefer the more brightly coloured chicks when it comes to feeding their offspring. However, no study had explained the reason for this strange behaviour. It was succeeded by the professor of ecology and evolutionary biology Bruce Lyon who, together with his colleague Daizaburo Shizuka from the University of Nebraska-Lincoln, published a study on Proceedings of the National Academy of Sciences.

Initially the researchers had thought that it was the chick, through evolutionary pathways, that could manipulate parents to get more food. However, in the course of the experiments that the researchers carried out, using, among other things, a photospectrometer to measure the precise color gradations of more than 1500 coot chicks, they found that this behavior is related to another one that sees mothers feed more some chicks instead of others to make sure that at least part of them can survive in strength since the available food is almost never enough for everyone.

The researchers initially discovered the mother, during the first 10 days after hatching the eggs, showed no preferences and fed all the chicks in which way. However, 10 days after the last hatching, the parents began to check the food allocation to ensure that at least one of the chicks could grow in strength. The latter began to receive preferential feeding and grew faster, becoming stronger and more resilient. However, parents tend to choose the chicks that are born later, which are, incidentally, the most colourful. In comparison with the others, he carries out a sort of aggression called “tousling”: he shakes them by the back of the neck to prevent them from eating too much.

“The male and the female share the brood, with each parent feeding only their half of the brood, and each parent also chooses a favourite. The colour predicts which one they choose, therefore the ornament can serve as signal for telling them which chick needs the maximum help,” explains Lyon himself. “They start by creating an irregular playing field, which allows them to break down the brood, and then they intervene to level the field. Orange plumage seems to be a feature that helps them do that.”

Among other things, this also explains why the eggs that mothers lay in the nests of other mothers, a behaviour known as “brood parasitism” and typical also of other species of birds, are less coloured. The eggs that the females lay in the nests of strangers are the first in the laying sequence and therefore are characterized by a lower pigment. With this preferential behaviour, parents are therefore more likely to feed their own child than the child of another.

Vitamin D defends against infections in skin wounds

According to new experiments conducted by researchers at Oregon State University (OSU), vitamin D can be of great help in preventing infections, particularly those that can arise as a result of injuries to the skin.

According to the researchers, in fact, the treatment with vitamin D greatly reduces the number of pathogens in wounds by regulating an important antimicrobial peptide in the body. In the study, published in the Journal of Steroid Biochemistry and Molecular Biology, is in fact described as vitamin D, present in a few foods including beef liver, cheese, egg yolks and fatty fish meat, promotes the production of catelicidin (CAMP), an antimicrobial peptide made of immune cells and cells that act as a barrier against infection.

The same gene that encodes catelicidin is present in humans and other primates. In other mammals, including mice, there is a gene that resembles it but is not activated by vitamin D. In fact, researchers carried out experiments on mice by grafting the human CAMP gene into them: rodents showed greater resistance to intestinal and staphylococcal infections on the skin.

Adrian Gombart, a scientist at OSU, and one of the authors of the study, says in the press release: “With our mouse model, we have shown that treating a skin wound infected with S. aureus with the bioactive form of vitamin D significantly reduced the number of bacteria in the wound.”

Arid and very dry phases much more common in the Americas than thought

Periods of drought in the Americas would be surprisingly common according to a study conducted by Columbia University paleoclimatologist Nathan Steiger. The scientist has in fact analyzed the tree trunk rings and found, as he explains in his study in Science Advances, several evidence that very dry climatic phases, such as those involving California this year or Chile in recent years, are actually very common.

The speech would be related to at least the last 12,000 years. According to the researcher, these very dry climatic phases have in common an abnormally very cold phase in the eastern Pacific Ocean and a process also known as La Niña.
Moreover, these analyses, making a projection into the future, suggest that further periods of extreme aridity could also involve the entire west coast of the Americas.

This study follows other studies that analyzed dead tree stumps located in the middle of lakes and rivers in Patagonia and the Sierra Nevada in California in the mid-1990s. Trees growing in watercourses or lakes indicated that drought levels so others must have lasted for decades. But it was only with this study, during which the scientist analyzed the tree rings, that the researchers used data covering much larger regions.

In addition, by combining these data with data on corals, ocean sediments and ice cores, the researcher has generated a kind of global vision of how the climate is changing. The research would confirm that from 800 to 1600 A.D., many such arid phases would have occurred in various parts of the world.

In particular the arid phases in the southwest of the United States were influenced by three factors, according to Steiger and the other authors of the study: the area of the North Atlantic Ocean abnormally hot, slight increases in global temperature and La Niña. As far as the arid phases of South America are concerned, it would be mostly only La Niña that would be the main trigger.

Now it remains to be seen how these drought patterns will change with ongoing global warming if it does. It is expected that with a warmer climate the drier phases will increase, but it is not so simple: scientists themselves remain divided on how the current climate change will affect the dry phases of certain areas. The drought that has been seen in Chile in recent years could, in any case, only be a faint example of what could happen in the future with consequences that could be catastrophic.

Alzheimer’s vaccine even closer to reality thanks to a new study

The possibility of a vaccine against dementia is getting closer and closer to reality thanks to a new study conducted by researchers from the Institute of Molecular Medicine and the University of California, Irvine (UCI), published in Alzheimer Research & Therapy. The treatment, which has already been successful in experiments on mice to which the vaccine was injected intramuscularly, could now proceed to clinical trials in humans.

It is a new vaccine that removes “brain plaque” and those protein aggregates called tau that are linked to Alzheimer’s disease itself. Neurodegeneration and cognitive decline of Alzheimer’s disease are in fact caused by the so-called accumulating beta-amyloid plaques (Aβ) and TAU proteins.

Anahit Ghochikyan, one of the main authors of the study together with Hvat Davtyan and Mathew Blurton-Jones of the UCI, explains the success obtained during the experiments with mice that, once treated with the vaccine, developed antibodies specific for Aβ and tau: “Our approach is trying to cover all the bases and overcome previous blockages in the search for a therapy to slow down the accumulation of Aβ/tau molecules and delay the progression of Alzheimer’s disease in an increasing number of people worldwide.

This new vaccine could help trigger the body’s immune responses against Alzheimer’s disease in a large population of subjects.

Scientists analyse quantities of water on 19 exoplanets and find less water than theorised

A study examining the amounts of water present in the atmospheres of 19 exoplanets was carried out by a team of astrophysicists at the University of Cambridge. The researchers concluded that although water, mainly in the form of water vapour, is common in exoplanet atmospheres, the level of presence is lower than expected.

As explained on Space.com Nikku Madhusudhan, one of the authors of the study, the chemical substances that were most commonly found in the atmospheres of other planets were sodium and potassium, whose amounts were consistent with expectations unlike water vapor. It was precisely the amount of water that surprised Madhusudhan himself, who, together with his colleagues, examined the atmospheres of the 19 exoplanets thanks to the data collected by various space and terrestrial telescopes.

The planets analyzed had surface temperatures ranging from 20° to 2000° centigrade and various sizes, from mini-Neptune with 10 times the Earth’s mass to gaseous supergiants with 600 times the Earth’s mass, so a good catalogue of planets although the number analyzed (19) was not so high.

At present, however, forecasts remain uncertain as to how much water can actually hide on average in exoplanets, also because it is not so easy to detect it in gaseous planets. An example could be Jupiter in our solar system: as explained by Luis Welbanks, another author of the study and astrophysicist at the University of Cambridge, Jupiter is so cold that water vapour begins to condense and is no longer visible in the thick gaseous atmosphere. On Jupiter there could be a lot of water or very little water, but with the tools we have available today it is not yet known.

This should not, however, weaken the research of extraterrestrial life: as the researchers explain, in fact on Earth there is not that much water at mass level. According to Madhusudhan the Earth itself could be considered “slightly below sufficient” as far as the amount of water is concerned so the fact that there is a smaller amount of water on exoplanets compared to the theories previously formulated should not necessarily represent bad news as far as their habitability is concerned.

A new dinosaur in Japan that lived 72 million years ago was just classified

A new Hadrosaurus dinosaur that lived in the late Cretaceous was classified by a group of Japanese researchers.

The study, published in Scientific Reports, talks about the methods of analysis performed by researchers on a fossil found in the formation of Hakobuchi, an island of Hokkaido.

The new dinosaur has been named Kamuysaurus japonicus. The first term refers to “Kamuy,” a deity of the Ainu, an indigenous population of the Japanese island of Hokkaido. The second term refers to Japan.

The discovery, made by Yoshitsugu Kobayashi and colleagues, is related to an adrosaur of about eight meters long that lived about 72 million years ago. It can be considered an average-sized adult hadrosaur weighing 4 tonnes or 5.3 tonnes, depending on whether it was walking on two or four legs.

Unique features found by researchers include a small crest on the head and a row of neural spines pointing forward. According to the researchers, the Kamuysaurus japonicus is related to other adrosaurs whose fossils have been found in the Far East. Among the latter are the Chinese Laiyangosaurus and the Russian Kerberosaurus.

Important discovery

This is an important discovery because it could allow a better understanding of the evolution of the Hadrosaurids during the late Cretaceous period, from 100.5 to 66 million years ago, that is until the period of the very disappearance of the dinosaurs.

Moreover, the fact that it was found near the sea, makes this fossil an important finding in relation to the understanding of the development and evolution of the same adrosaurids in such environments. This discovery, in fact, suggests that the members of the adrosaurids and its subfamilies, Hadrosaurinae and Lambeosaurinae, preferred to live near the coasts.

Links/Sources:

https://www.nature.com/articles/s41598-019-48607-1

Classified trout genome: researchers now hope to solve taxonomic issues

A group of researchers completed the genomic sequencing of trout (Salmo trutta), one of the most discussed fish at the taxonomic classification level.

Different species of trout have adapted to exploit particular biological niches and very often can be characterized by very different behavioral patterns. Many scientists believe that it is not possible to group all trout populations into one species. For this very reason, in recent years there have been many subspecies of trout proposed for a new classification and for several of them the elevation to the rank of species has been proposed.

In addition to helping to explain the various genetic properties of this animal, this complete sequencing may be useful to clarify these taxonomic issues, in particular by making comparisons between the genomes of different species having a reference genome.

“Now that we have the genome, we can start learning more about how trout adapt to different conditions, helping to manage wild and farmed fish stocks in the future,” says Tom Hansen, of the Marine Research Institute in Norway, one of the researchers involved in the study.

Paolo Prodohl, a researcher at the School of Biological Sciences at Queen’s University in Belfast, said in his press release: “The new trout genome is a turning point for us. We will finally be able to resolve the debate on how many species of trout there are. If you think in terms of conservation, if you manage several species as one species, it actually undermines what you’re trying to do. Because you can’t protect what you don’t know if it exists.”

Links/Sources:

https://www.cambridgenetwork.co.uk/news/brown-trout-genome-will-help-explain-species-genetic-superpowers

Scientists create a catalog of human gut bacteria

A team of researchers from MIT and the Broad Institute has created a vast sample book containing nearly 8000 strains of bacteria from the human intestinal microbiome. As has long been known, most of these bacteria are useful or otherwise not harmful but there is a small minority that contributes to various health problems, including inflammatory bowel diseases.

The data set is available to all other researchers the hope of its creators is that it will help shed more light on the various dynamics of the many populations of bacteria found in the digestive tract of humans, as specified by Eric Alm, director of the Center for Microbiome Informatics and Therapeutics as well as professor at Al MIT.

The database was created by analyzing the stool collected from about 90 people in the Boston area over the course of two years. Currently, researchers are trying to improve the same database by analyzing samples from around the world. In this way, for example, it will be possible to identify and catalog the microbial strains that are not found in the intestinal tracts of those people who live in an industrialized area and in any case the catalog will certainly be more complete.

“Exploring this genetic and functional diversity is fascinating – wherever we look, we discover new things. I am convinced that enriching biobanks with a wide variety of strains from individuals living different lifestyles is essential for future progress in human microbiome research,” reports Mathilde Poyet, MIT researcher and one of the main authors of the study that appeared in Nature Medicine.

This study fits into the current stream of new research that is increasingly taking into account the weight and general importance of human microbes. Despite the numerous researches, at the moment it is still difficult to understand the functions of many bacteria and the links they may have with various diseases.

Links/Sources:

http://news.mit.edu/2019/catalogue-human-digestive-gut-bacteria-0902

The birds that live around Lake Constance are disappearing

According to a new study, the number of birds living around Lake Constance is in sharp decline. The results of the study show that the lake region has lost 120,000 breeding copies over the past 30 years.

Six of the most common bird species living around the lake have declined dramatically in number and only two of these species have increased. For example, the population of domestic sparrows has decreased by 50% since 1980 while swallows have decreased by 70%.

The partridge, which was once a very common bird in the land around the lake region, has instead completely disappeared as has the owl. They are also suffering from species that usually survive almost everywhere, such as finches, robins and blackbirds.

These are “really shocking figures,” as Hans-Günther Bauer, a researcher at the Max Planck Institute for Animal Behaviour, says, and they would have been even stronger if the count had started before 1980 as the decline began decades earlier. If we were to make a projection into the future, the decline would therefore have to be even greater.

The problem of habitat is the biggest one: bird populations are shrinking rapidly in those areas and are being used intensively by humans, especially in agriculture. Another reason is the scarcity of food: insects are also decreasing around the region and even the latter are disappearing by human hand.

Links/Sources:

https://www.mpg.de/13849147/dramatic-decline-of-birds-at-lake-constance

Australian birds are losing much of their habitat

Hundreds of Australian bird species are losing their habitat, especially in South-East Australia. A new study published in Conservation Biology has analyzed various threatened and unthreatened bird species and found that they have lost almost two-thirds of their natural habitats.

The same study differs from the others because it also takes into account non-threatened species. Jeremy Simmonds, the study’s head, himself, specifies how all too often only threatened birds are highlighted or researched.

In fact, even the most common and most widespread species can be endangered and can be important for the environment, as the researcher himself specifies: “Common species play a vital role in controlling pests and pollination of insects and their decline through loss of habitat has implications for the health of ecosystems.”

Researchers analyzed changes in the habitats of 447 different Australian bird species since 1750. Needless to say, the greatest negative changes have occurred in those areas where there has been greater deforestation.

The same researcher calculates that for every hectare of forest felled 180 different species of birds are affected in terms of habitat loss.

Links/Sources:

https://conbio.onlinelibrary.wiley.com/doi/abs/10.1111/cobi.13331