A team of scientists led by international conservation charity ZSL (Zoological Society of London) discovered that ancient bones from the extinct Madagascan elephant birds (Aepyornis and Mullerornis) show cut marks and depression fractures consistent with hunting and butchery by prehistoric humans. Using radiocarbon dating techniques, the team were then able to determine when these giant birds had been killed, reassessing when humans first reached Madagascar.

Previous research on lemur bones and archaeological artefacts suggested that humans first arrived in Madagascar 2,400-4,000 years ago. However, the new study provides evidence of human presence on Madagascar as far back as 10,500 years ago — making these modified elephant bird bones the earliest known evidence of humans on the island.

Lead author Dr James Hansford from ZSL’s Institute of Zoology said: “We already know that Madagascar’s megafauna — elephant birds, hippos, giant tortoises and giant lemurs — became extinct less than 1,000 years ago. There are a number of theories about why this occurred, but the extent of human involvement hasn’t been clear.

“Our research provides evidence of human activity in Madagascar more than 6,000 years earlier than previously suspected — which demonstrates that a radically different extinction theory is required to understand the huge biodiversity loss that has occurred on the island. Humans seem to have coexisted with elephant birds and other now-extinct species for over 9,000 years, apparently with limited negative impact on biodiversity for most of this period, which offers new insights for conservation today.”

Co-author Professor Patricia Wright from Stony Brook University said: “This new discovery turns our idea of the first human arrivals on its head. We know that at the end of the Ice Age, when humans were only using stone tools, there were a group of humans that arrived on Madagascar. We do not know the origin of these people and won’t until we find further archaeological evidence, but we know there is no evidence of their genes in modern populations. The question remains — who these people were? And when and why did they disappear?”

The bones of the elephant birds studied by this project were originally found in 2009 in Christmas River in south-central Madagascar — a fossil ‘bone bed’ containing a rich concentration of ancient animal remains. This marsh site could have been a major kill site, but further research is required to confirm.

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Ancient Mesoamerican cultures used wild animals such as puma and jaguar for many purposes, including in symbolic displays of status and power, as subjects of ritual sacrifice, and as resources for processing into venison or craft products. Evidence of wild animal use in ancient Mesoamerica dates back to the Teotihuacan culture in what is now central Mexico (A.D. 1-550). Archaeological findings of indigenous Mesoamerican animal management strategies have traditionally been underemphasized, due to the paucity of large domesticated game in the New World in comparison to the devastating impact of European livestock introduced in the 1500s. In this study, the research team analyzed archaeological samples of wild animals excavated from five ritual sites in the Maya city of Copan (A.D. 426-822), in Honduras.

The team performed stable isotope analyses on bone and teeth from puma, jaguar and other unidentified felids along with deer, owl, spoonbill, and crocodile, to determine the diet and geographical origin of the animals. Some of the felid specimens tested, including puma and jaguar, had high levels of C4 intake indicative of an anthropogenic diet despite the absence of indicators of captive breeding. Oxygen isotope levels in deer and felid specimens suggest that some animals and derived craft products (e.g. pelts) used in ritual practices originated in distant regions of the Copan Valley.

These findings confirm previous research showing that Mesoamerican cultures kept wild animals in captivity for ritual purposes and reveal that animal trade networks across ancient Mesoamerica were more extensive than previously thought.

Sugiyama summarizes: “Encoded into the bones of jaguars and pumas at the Maya site of Copan was evidence of both captivity and of expansive trade networks trading ritualized carnivores across the dynamic Mesoamerican landscape.”

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For women, it usually accumulates around the hips, resulting in a pear-shaped look. In men, fat tends to build up around the abdomen, creating an apple shape.

As it turns out, it’s healthier to be a pear than an apple.

A research team at the University of California, Riverside, has found that only male mice experienced neuroinflammation, or activation of the immune system’s response in the brain, after being fed a high-fat diet. While females were unaffected, males showed low testosterone and reduced sperm count, in addition to neuroinflammation.

Study results appear in the journal Frontiers in Immunology.

Clinical studies have led researchers to believe females are protected against weight gain when they are young because of ovarian estrogen. The understanding has been that women gain weight after menopause because of a precipitous drop in estrogen, resulting in a decline in health parameters, including obesity.

“We addressed this assumption by removing ovaries in young mice,” said Djurdjica Coss, an associate professor of biomedical sciences in the UCR School of Medicine, who led the study. “We found that the mice proceed to gain weight when fed a high-fat diet, suggesting that ovarian hormones are indeed protective against weight gain. But we found, too, that these female mice exhibit neither neuroinflammation, nor changes in reproductive hormones, suggesting that they are protected by factors other than ovarian estrogen. This is a novel finding.”

The findings, derived from the mouse study, are likely to have applications in humans, Coss added.

“Mice on high-fat diet develop metabolic syndrome — a constellation of pathologies that includes Type 2 diabetes and insulin insensitivity — similarly to obese humans,” she said. “Obese men have lower testosterone levels, contributing to low libido, low energy, and reduced muscle strength. We see this in mice, too; obese male mice showed nearly 50 percent decreases in testosterone and sperm number. Obese women have difficulty with their menstrual cycles. They don’t ovulate. Obese female mice show the same, contributing to decreased fertility. Interestingly, 18 percent of couples in the United States now need medical interventions — hormonal treatments, in vitro fertilization — to conceive a child. Obesity is a likely factor.”

Increased obesity is a public health concern in the United States, where more than 30 percent of people are obese, and more than two-thirds are overweight. Obesity has been associated with mental decline and an increased rate of stroke, in addition to other problems affecting the internal organs. In the U.S., some ethnic minority groups are disproportionately affected by obesity.

Female women and mice deposit fat differently than their male counterparts. Females deposit fat subcutaneously, right below the skin, while males accumulate fat deeper, in the body’s visceral region, which may affect internal organs.

Eventually, even in women, the subcutaneous regions get overwhelmed with fat and the abdominal region begins to show obesity, which leads to neuroinflammation.

“While overweight, women are more protected than men where neuroinflammation is concerned,” Coss said. “This could be an evolutionary protection for women, who need to experience more change in weight due to pregnancy. This protection is significantly curtailed when overweight women become obese and fat gathers around the waist.”

Next, Coss and her team will explore, in mice, how abdominal weight is linked to neuroinflammation.

“We know that abdominal fat — that is, fat around visceral organs — gets more inflamed with a fat overburden,” she said. “This fat then recruits immune cells from blood circulation that get activated.”

Another important finding reported in the study is that peripheral immune cells, macrophages in particular, cross the blood-brain barrier — the protective barrier stopping the influx of most compounds from the blood to the brain. This infiltration of peripheral immune cells into the brain occurs in addition to the activation of resident immune cells.

“The brain has been considered an ‘immune protected site,’ but we show that peripheral inflammation ‘spills over’ into the brain, which, in turn, may cause neuronal problems mentioned above,” Coss said.

Coss explained that it is unclear what causes this activation, and that her research team plans further investigation.

“We know the immune cells secrete cytokines, which are inflammatory markers, in the blood. It’s possible these cytokines travel in blood from the fat tissue and activate the immune cells to cross the blood-brain barrier,” she said. “It’s possible, too, that other immune cells contribute to the neuroinflammation. Clearly, our work has provoked several research questions we would like to answer.”

Coss acknowledged weight is a sensitive topic even for clinicians who have a difficult time talking about it to patients.

“After all, we associate food with happiness, social interactions, and family gatherings,” she said. “Still, my advice is: ‘Watch your diet! And keep an eye on body weight, particularly around the abdomen.'”

Coss, who joined the UCR School of Medicine in 2013, was joined in the study by her graduate student Nancy M. Lainez (first author), Carrie R. Jonak, and four School of Medicine faculty members: Meera G. Nair, an expert in immunology; Iryna Ethell, an expert in brain function; Emma H. Wilson, an expert in neuroinflammation; and Monica Carson, an expert in blood-brain interactions. The interdisciplinary research was supported by UCR startup funds.

Scientists observe the L-H transition is always associated with zonal flows of plasma. Theoretically, zonal flows in a plasma consist of both a stationary flow with a near-zero frequency and one that oscillates at a higher frequency called the geodesic acoustic mode (GAM), which is a global sound wave of the plasma. For the first time, researchers at Hefei University of Technology have detected GAM at two different points simultaneously within the reactor. This new experimental setup will be a useful diagnostic tool for investigating the physics of zonal flows, and their role in the L-H transition. The researchers report these findings in a new paper published in Physics of Plasmas, from AIP Publishing.

Zonal flows occur anywhere there is turbulence, such as inside a fusion device or in a planet’s atmosphere. “The most famous zonal flows in nature may be the well-known Jovian belts and zones, which make Jupiter look like a colorful, multilayered cake,” said Ahdi Liu, an author on the paper. In fusion plasmas, zonal flows are crucial for regulating turbulence and particle transport within the reactor. “With the gradual improvement of diagnostic technology, zonal flows in fusion plasma has become a research hot spot in the past two decades,” Liu said.

In these experiments, researchers used the Experimental Advanced Superconducting Tokamak (EAST), a magnetic fusion energy reactor in Hefei, China. They installed two Doppler reflectometers on different sides of EAST, which can detect fluctuations in turbulence and plasma density with high precision. The detected GAM had a pitch of F, five octaves above middle C.

Previously, researchers at ASDEX-U, the fusion research device at the Max Plank Institute of Plasma Physics, used a similar system to detect GAM, but they measured the plasma at a single location, which makes the setup prone to interference. “This disadvantage is the main motivation for using two sets of Doppler reflectometers,” Liu said. “We could ‘purify’ the GAM information by comparing the two location’s measurements.”

The measurements taken at the two points did not entirely agree, showing that each reflectometer also picked up information from nonzonal flows. “It is completely necessary to extract accurate zonal flows information from multipoint measurement,” Liu said. Using both measurements, they could clearly show that GAM interacted with the ambient turbulence. Going forward, the researchers will further investigate the role of zonal flows in turbulence and turbulent transport within EAST.

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