The scientists found that the novel species were attacked more than the familiar species and that the brightly-colored species were attacked less than the more camouflaged species. The models resembling the local, red and blue frogs were attacked the least, suggesting that natural selection will continue selecting frogs with this color scheme to pass on their genes in La Selva.
In addition to coloration playing a role a survival, it also plays a part in reproduction, the other driving force of natural selection.
According once again to Cummings, birds can only detect differences in color, but not varying degrees of brightness. It turns out that frogs are adept at detecting brightness and that females are most attracted to males with the most brilliant colors. Fanimal is a socially-minded organization focused on animals. We provide original content on a variety of topics delivered through web-based platforms.
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In this hostile environment, slow-growing bacteria survive by relying on sinking organic matter , including proteins and carbohydrates called polysaccharides, from algae in the sun-lit surface waters of the ocean.
Much of this organic matter is heavily degraded by the time it reaches the deep sea, and intact polysaccharides are hard to come by. For bacteria living in the bathypelagic zone, survival means getting the most out of every rare polysaccharide that reaches these depths — and a new study suggests that for some bacteria, selfishness may be key to their survival.
Bacteria typically feed by releasing enzymes into the water to break down their food into small enough pieces to be taken into the cell. However, by releasing these enzymes into the surrounding water, bacteria naturally lose some of the products of this process.
While breaking down food externally can be profitable when resources are in high abundance , it is a much less successful strategy in environments where resource availability is low, such as the deep sea.
In a recent pre-print that I am a co-author on, we suggest that some bacteria at these depths may be using a selfish method of polysaccharide uptake. This method allows them to bring large pieces of polysaccharides into their cells without first breaking them down externally, enabling the bacteria to selfishly keep all the food to themselves.
To make this discovery, we incubated bathypelagic bacteria with fluorescently-labeled polysaccharides. By staining the bacteria with a DNA-binding dye and viewing them under microscopes, we were able to see intact pieces of polysaccharides inside the cells, indicating that these bacteria had not used external enzymes to break them down prior to uptake.
These results provide the first example of selfish behavior in deep-sea bacteria, suggesting that selfishness may be more common among bacteria than previously thought. Photo by Jorge Ramirez on Unsplash.
Indoor chemists are especially concerned with volatile organic compounds VOCs, a class of molecules that includes benzene, formaldehyde, and more , which can be harmful to human health and are highly reactive. VOCs are released into indoor air from a number of sources — plants , wall paint , cooking and cleaning — and, as a recent study by a pair of researchers at the University of Toronto shows, from LCS screens like those in your phone, TV, and laptop.
To measure how LCD screens affect air quality, the researchers collected data on what types of compounds were contained in two types of samples: one of regular indoor air, and one collected near the surface of on an LCD screen like a new TV or an old laptop. They identified the chemical signatures of those compounds using a technique called proton-transfer reaction mass spectrometry.
They found over 30 VOCs and 10 L liquid crystal monomers were heavily emitted into the air exposed to the screen, including extremely reactive species like isoprene and acetic acid.
This finding indicates that LCD screens are an important source of VOCs in indoor environments, and that our screen-time may be exposing us to more than just new things on the internet. Photo by Erin Aguis on Unsplash. About 69 percent of people in the US who are 12 years or older have received the full vaccine dosage, thus protecting them from COVID Yet, a portion of the remaining population remains reluctant to get the vaccine.
This group's decision is based on their concern about the vaccine's safety, lack of belief in the danger posed by COVID, and distrust for the government. Some also face logistical difficulties in getting vaccinated, either because they live in rural areas or do not have the ability to take sick days from work if they experience side effects. A promising new study , published by researchers at the University of Southern California, found that individuals had significant decreases in mental health distress after receiving the first dose of the vaccine.
This knowledge can, hopefully, push some vaccine hesitant people to receive their shots. They found that vaccinated individuals reported less mental distress after receiving the first dosage, while the unvaccinated group retained a consistently high level of mental distress for the entire 1-year study period.
Receiving the vaccine has turned from a health to a political affair as the remaining population voluntarily refuses to get vaccinated. This voluntary refusal puts themselves, the community, and individuals who cannot get vaccinated like children under five years old and immunocompromised individuals at greater risk of being infected with COVID At this point, severe reactions to COVID are preventable but will remain a significant problem until all eligible persons are vaccinated.
This study shows that we have an opportunity to increase our physical and mental wellbeing. We must invest in more substantial policy at the corporate, state, and federal levels to increase vaccination rates now. Due largely in part to human-induced climate change, up to 40 percent of all species of plants are at risk of extinction.
In response, conservationists have developed seed banks , where seeds of at-risk plants are frozen and stored in case of emergency. Many species of oak trees fall on the list of endangered plants.
However, their acorns are not usable after freezing, so conservationists are unable to add them to seed banks. As a result, scientists have had to investigate alternative preservation methods for oaks. A recently published study has demonstrated that, for oaks, an alternative to seed-banking could be shoot tip cryopreservation. Shoot tip cryopreservation is the process of clipping off the shoot tip of a plant — the part that contains cells able to regenerate into a whole new plant — and placing it in droplets of a freezable substance.
The plants are then frozen in liquid nitrogen, degrees Fahrenheit, until they're ready to be thawed and grown. Scientists found that, when they attempted shoot tip cryopreservation on four different species of oaks, some the plants were able to grow after freezing and unfreezing.
But some didn't survive. Survival depended on the species. One species survived liquid nitrogen freezing 56 percent of the time, another never did.
When looking specifically at the most successful species, the researchers also found that slight temperature differences in the freezing and unfreezing processes can have an effect on both general plant survival and exactly how well the plants recover after freezing.
Up until now, there had been no evidence that shoot tip cryopreservation worked on oaks. While survival does depend on the species of oak, this study demonstrates that this method can be added to the arsenal of the different conservation tools available for oak preservation, and can hopefully contribute to finding methods that work for all oak species. Memory is the process of encoding, storing and retrieving information by the brain.
Several studies indicate that fear memories are processed differently in male and female animals, but the basis of these differences are still mostly unknown.
A study published in Nature Communications has brought new information to the table: a drug known to reduce the ability to remember fearful events in male mice turns out to to increase that ability in females. They study the mechanisms of the memory of fear, aiming to find treatments for pathologies associated with the experience of traumatic events.
This project coupled behavioral studies of mice with hormonal and biochemical and molecular analysis. The drug they used in the study, osanetant which is not used to treat humans , blocks a pathway for brain signaling that is involved in creating lasting memories of fear.
The researchers found that the drug's blocking action has opposite effects on males and females, and that it is dependent on sexual hormones — testosterone in males and estradiol in females.
While the new results about sexual differences and memory are very interesting on their own, they raise an important issue for experimental design. Most research studies are done in males. But scientists would benefit from understanding how drugs affect more than just males.
That's particularly relevant in this field in particular, given that fear related disorders are more common in women. Since their introduction in the late s , selective-serotonin reuptake inhibitors SSRIs have become the go-to treatment for major depression.
SSRIs, however, have a number of limitations: they take several weeks to start working, can cause a variety of side-effects , and do not help some people with depression.
A series of recent clinical investigations suggest that psilocybin, the active compound in magic mushrooms, may be an effective alternative.
One question that these studies left unanswered, however, is how effective psilocybin treatment is compared to SSRIs. The six-week long study enrolled 59 volunteers with moderate-to-severe major depression.
They were randomly and blindly assigned to receive treatment with psilocybin and an escitalopram control, or escitalopram and a psilocybin control. All the participants also received psychological support. The researchers did not detect a statistically significant difference between the two treatments. The results of other measures taken in the study, however, suggest that psilocybin may be more effective than escitalopram. When designing the study, the researchers determined that the QIDS-SR most directly addressed their experimental question and would therefore be the primary outcome measure, but they also evaluated depression symptoms with a number of additional scales.
Nearly all secondary outcome measures favored psilocybin over escitalopram, but their results hold less weight than the QIDS-SR because of how the study was designed. The study was also limited by its small size, non-random enrollment of interested volunteers, and the possibility that participants may have been unblinded by the strong subjective effects of psilocybin or the well-known side-effects of SSRIs. Nonetheless, as the most rigorous evaluation of the therapeutic potential of psilocybin conducted to date, the results provide a benchmark for the design of future investigations.
Photo by Omar Flores on Unsplash. Neuroscientists are known for doing some strange things to mice in their pursuit of learning about the brain. In a study recently published in Neuron , researchers found that cocaine use changes the DNA in mouse brains, specifically in the brain regions associated with reward. After consuming cocaine, the DNA in their brain cells had different chemical modifications known as epigenetic changes. These epigenetic changes also altered the types of RNAs the cells made through splicing.
In this process, pieces of genes are left out or added in to create different RNAs that create different proteins. Scientists have known RNA splicing is particularly important for neurons, and the researchers behind this mouse study saw many epigenetic and splicing changes after the mice consumed cocaine. Then, they artificially recreated one specific epigenetic change at a gene called Srsf This led Srsf11 to be spliced differently. However, Srsf11 is also a gene that controls splicing across the genome, meaning that changes to it had ripple effects in the mice.
This one change also altered splicing across a few hundred other genes, some of which were previously implicated in substance use disorders. Most interestingly, the mice with the modified version of Srsf11 self-administered more cocaine, showing that these sorts of changes in the brain may underlie addiction.
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