With teeth like that, this pre-dinosaur vegetarian was no push over

Discovered four years ago, and following an updated and more in-depth study of the herbivorous mammalian ancestor, Tiarajudens eccentricus, researchers from Brazil and South Africa can now present a meticulous description of the skull, skeleton and dental replacement of this Brazilian species.

They also learned that 270 million years ago, the interspecific combat and fighting we see between male deer today were already present in these forerunners of mammals.

This description by Brazilian researcher, Dr Juan Carlos Cisneros, and his co-authors from the Evolutionary Studies Institute at the University of the Witwatersrand, Professor Fernando Abdala and Dr Tea Jashasvili, is published in an article, titled: Tiarajudens eccentricus and Anomocephalus africanus, two bizarre anomodonts (Synapsida, Therapsida) with dental occlusion from the Permian of Gondwana in the journal, Royal Society Open Science, on 15 July 2015.

Saber-teeth are known to belong to the large Permian predators' gorgonopsians (also known as saber-tooth reptiles), and in the famous saber-tooth cats from the Ice Age.

When Tiarajudens eccentricus was discovered it had some surprises install: Despite large protruding saber-tooth canines and occluding postcanine teeth, it was an herbivore. The discovery of this Brazilian species also allowed for a reanalysis of the South African species Anomocephalus africanus, discovered 10 years earlier. The two species have several similar features that clearly indicated they are closely related but the African species lack of the saber-tooth canines of its Brazilian cousin. In the Middle Permian, where these Gondwana cousins were living, around 270 million years ago, the first communities with diverse, abundant tetrapod herbivores were evolving.

In deer today enlarged canines are used in male-male displays during fighting. The long canine in the herbivore T. eccentricus is interpreted as an indication of its use in a similar way, and is the oldest evidence where male herbivores have used their canines during fights with rivals.

"It is incredible to think that features found in deer such as the water deer, musk deer and muntjacs today were already represented 270 million years ago," says Cisneros.

The researchers found the Tiarajudens' marginal teeth are also located in a bone from the palate called epipterygoid. "This is an extraordinary condition as no other animal in the lineage leading to mammals show marginal dentition in a bone from the palate," says Abdala.

In another group of mammal fossil relatives, dinocephalians -- that lived at the same time as anomodonts, some of the bones in their foreheads were massively thickened. This can be interpreted as being used in head-butting combat, a modern behaviour displayed by several deer species today.

"Fossils are always surprising us. Now they show us unexpectedly that 270 million years ago two forms of interspecific combat represented in deer today, were already present in the forerunners of mammals," says Cisneros.

Human hands may be more primitive than chimp's

Today, Nature is publishing a paper "The evolution of human and ape hand proportions," a study that discovers that human hands may be more primitive than chimp's.

The work is done by Stony Brook University's Sergio Almecija, Jeroen Smaers and William Jungers.

Human hand proportions have changed little from those of the last common ancestor (LCA) of chimpanzees and humans. These findings indicate that the structure of the modern human hand is largely primitive in nature, rather than the result of selective pressures in the context of stone tool-making.

Human hands exhibit a long thumb in relation to the fingers. This is one of the most distinctive traits of humankind compared to apes and is often cited as one of the reasons for the success of the species; however there are competing theories on how the human hand evolved over time.

The researchers measured the hand proportions of humans, living and fossil apes as well as fossils of human ancestors including Ardipithecus ramidusand Australopithecus sediba, to understand the step wise evolution of the hand. Their results show the more recent, convergent evolution of finger elongation in chimpanzees and orangutans and comparatively little change between humans, human ancestors and gorillas.

These results support the hypothesis that the long thumb to fingers ratio of the human hand was acquired convergently with other highly dexterous anthropoids. The findings of the study also challenge the assumption that a chimp-like hand was the starting point of the chimpanzee-human LCA.

Herbal extract boosts fruit fly lifespan by nearly 25 percent

The herbal extract of a yellow-flowered mountain plant long used for stress relief was found to increase the lifespan of fruit fly populations by an average of 24 percent, according to UC Irvine researchers.

But it's how Rhodiola rosea, also known as golden root, did this that grabbed the attention of study leaders Mahtab Jafari and Sam Schriner. They discovered that Rhodiola works in a manner completely unrelated to dietary restriction and affects different molecular pathways.

This is significant, said Jafari, associate professor of pharmaceutical sciences, because dietary restriction is considered the most robust method of improving lifespan in laboratory animals, and scientists have been scrambling to identify compounds that can mimic its effects.

"We found that Rhodiola actually increases lifespan on top of that of dietary restriction," Jafari said. "It demonstrates that Rhodiola can act even in individuals who are already long-lived and healthy. This is quite unlike resveratrol, which appears to only act in overfed or unhealthy individuals."

The researchers proved this by putting flies on a calorie-restricted diet. It has been shown that flies live longer when the amount of yeast they consume is decreased. Jafari and Schriner expected that if Rhodiola functioned in the same manner as dietary restriction, it would not work in these flies. But it did. They also tested Rhodiola in flies in which the molecular pathways of dietary restriction had been genetically inactivated. It still worked.

Not only did Rhodiola improve lifespan an average of 24 percent in both sexes and multiple strains of flies, but it also delayed the loss of physical performance in flies as they aged and even extended the lives of old flies. Jafari's group previously had shown that the extract decreased the natural production of reactive oxygen species molecules in the fly mitochondria and protected both flies and cultured human cells against oxidative stress.

Jafari and Schriner, an assistant project scientist in Jafari's laboratory, are not claiming that Rhodiola supplements will enable humans to live longer, but their discovery is enhancing scientific understanding of how supplements believed to promote longevity actually work in the body.

Rhodiola has already shown possible health benefits in humans, such as decreasing fatigue, anxiety and depression; boosting mood, memory and stamina; and preventing altitude sickness. Grown in cold climates at high elevations, the herb has been used for centuries by Scandinavians and Russians to reduce stress. It's also thought to have antioxidant properties.

Jafari's research group is currently exploring the plant's potential to kill cancer cells, improve Alzheimer's disease and help stem cells grow.

Rhodiola is readily available online and in health food stores. Jafari, though, has analyzed several commercial products and found them to not contain sufficient amounts of the reputed active compounds -- such as rosavin and salidroside -- that characterize high-quality products.

Old astronomic riddle on the way to be solved: Absorption of starlight in space

Scientists at the University of Basel were able to identify for the first time a molecule responsible for the absorption of starlight in space: the positively charged Buckminsterfullerene, or so-called 'football molecule' (shaped like a soccer ball). Their results have been published in the current issue of Nature.

Almost 100 years ago, astronomers discovered that the spectrum of star light arrived on earth with dark gaps, so-called interstellar bands. Ever since, researchers have been trying to find out which type of matter in space absorbs the light and is responsible for these “diffuse interstellar bands” (DIB) of which over 400 are known today.

Buckyball and interstellar clouds

Astronomers have been suspecting for a while that big complex molecules and gaseous ions based on carbon could be absorbing the starlight. The Buckminsterfullerene is such a molecule: a structure made up of 60 carbon atoms shaped like a football that was first discovered in the mid-1980s.

After this discovery, the questions arose if it was possible that the football molecule was in fact responsible for the DIB. The research team led by Prof. John P. Maier from the Department of Chemistry at the University of Basel has been studying the electronic absorption of the ionized Buckminsterfullerene since 1993. In fact, the spectrum measured in the lab did show absorption features at two wavelengths that were near two DIB that had been discovered by astronomers the following year.

Conditions similar to outer space

In order to unequivocally prove that these molecules absorb starlight and thus produce the DIB, a gas phase spectrum of the ion was needed. The Basel researchers now succeeded at this: “This is the very first unequivocal identification of such a molecule in the interstellar clouds”, says Professor John P. Maier. “We have achieved a breakthrough in solving the old riddle of the diffuse interstellar bands.”

In order to obtain the spectrum in the laboratory using a diode laser, several thousand ionized Fullerenes were confined in a radiofrequency trap and cooled down by collisions with high density helium to very low temperatures of around 6 degree Kelvin – conditions very similar to outer space.

The absorptions measured in the laboratory coincide exactly with the astronomical data, and have comparable bandwidths and relative intensities. This identifies for the first time two DIB and proves that ionized Buckminsterfullerene (C60+) is present at the gas-phase in space. “This is remarkable, considering the complexity of this molecular ion and the presence of high-energy radiation in such an environment”, says Maier.

Researchers stimulate human amygdala to gain key insight into sudden unexpected death in epilepsy

Sudden unexpected death in epilepsy (SUDEP) is becoming increasingly recognized as a very real and devastating problem in which impaired breathing is thought to play a critical role. Researchers believe breathing may be impaired during and after seizures, without the patient's knowledge.

By using electrical stimulation to activate the amygdala, a group of University of Iowa researchers has identified areas of the human brain in which breathing is controlled and, in some cases, impaired, providing an important insight into SUDEP.

Their study - which marks the first time researchers have stimulated the amygdala in humans and reported loss of breathing - is published in the July 15 issue of the Journal of Neuroscience.

Using a research participant with medically intractable epilepsy - epilepsy which can't be well-controlled with two or more medications - whose brain was already being monitored to map the focus of seizures, researchers found that when seizures spread to the amygdala, the patient stopped breathing. That effect could be reproduced by electrically stimulating the amygdala. Strikingly, the patient wasn't aware he wasn't breathing even though he was wide awake at the time. This finding was reproduced in two other human subjects.

"Amazingly, the patient was completely unaware that he had stopped breathing," says Brian Dlouhy, M.D., assistant professor of neurosurgery at UI Carver College of Medicine and lead author of the study. "It was remarkable to all of us that one of the essentials of life - breathing - could be inhibited and the patients themselves were completely unaware of this."

"The patient just sat there, unconcerned that he was not breathing," says John Wemmie, M.D., Ph.D., professor of psychiatry, molecular physiology and biophysics, and neurosurgery at the UI Carver College of medicine, and an author of the paper. "If we asked him to hold his breath for the same duration of time, it was difficult for him and he could barely do it. But when the amygdala was stimulated, he didn't even notice that his breathing had stopped."

Dr. George Richerson, M.D., Ph.D., professor and chairman of neurology, and professor of molecular physiology and biophysics, and neurosurgery at the UI Carver College of Medicine, also an author on the paper, says, "These findings provide an explanation for why SUDEP occurs after seizures, because patients would stop breathing but be completely unaware that their blood oxygen levels are progressively dropping to fatally low levels. The lack of awareness would prevent activation of the reflex that is needed to restore oxygen levels back to normal."

The team's findings may be key in helping to decrease instances of SUDEP, Dlouhy says.

"Identifying brain areas where seizure spread interferes with breathing may help identify patients at risk for SUDEP and lead to preventive strategies," he says.

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Story Source:

The above post is reprinted from materials provided by University of Iowa Health Care. Note: Materials may be edited for content and length.

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Journal Reference:

1. B. J. Dlouhy, B. K. Gehlbach, C. J. Kreple, H. Kawasaki, H. Oya, C. Buzza, M. A. Granner, M. J. Welsh, M. A. Howard, J. A. Wemmie, G. B. Richerson. Breathing Inhibited When Seizures Spread to the Amygdala and upon Amygdala Stimulation. Journal of Neuroscience, 2015; 35 (28): 10281 DOI: 10.1523/JNEUROSCI.0888-15.2015