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Researchers have finally created a quantum X-Ray device

Researchers have finally created a quantum X-Ray device

A research team has demonstrated quantum enhancement in a real X-ray machine, thereby achieving the goal of elimination of background noise for precision detection. The relationship between photon pairs on quantum scales can be used to generate sharp, high-resolution images compared to classical optics. This field is called quantum imaging and has huge potential since optical light can be used to show objects that cannot be seen normally like bones and organs. Quantum correlation describes several relationships between photon pairs, among which entanglement is one and it is used in optical quantum imaging.

The technical challenges of generating entangled photons in X-ray wavelength are greater than optical light, so the team used a different approach. They used a method called quantum illumination to minimize background noise. Using parametric down-conversion (PDC), the researchers split a high energy photon into two low energy photons, signal photon, and idler photon. Researchers mentioned that the application of X-Ray PDC as a source of ghost imaging has been demonstrated recently.  In previous publications, the photon statistics were not measured with any experimental evidence to date, which is generated by X-Ray PDC. Similarly, the observations of quantum enhancement sensitivity were not reported at X-ray wavelengths. The work appears in Physical Review X.

The X-Ray PDC was achieved with the help of a diamond crystal. The non-linear structure of crystal splits X-Ray photons into signal and idler beams, each having half the energy of the pump beam. The team scaled up power by using SPring-8 synchrotron in Japan. They shot a 22 KeV beam of X-rays at their crystal, splitting into two beams, carrying the energy of 11 KeV. The signal beam is sent towards the object which has to be imaged. Here, it is a small metal piece with three slits and a detector on the other side. The idler beam is directly sent to another detector so that each beam hits its respective detector at the same place and time.

The researchers then compared the detections. They found 100 correlated photons per point in the image and 10,000 background photons. Researchers could match each idler to the signal and could trace back the photons which came from the beam, thereby eliminating the noise. They later compared the images to the images developed using non-correlated photons. The correlated photons produced a sharper image.

Quantum X-ray imaging could have many uses outside current X-ray technology with a benefit of lower X-ray radiation required for imaging. This means that samples which are easily damaged by X-Rays could be imaged along with the samples with lower temperature requirement. As quantum X-Ray requires particle accelerator, there are no medical applications currently. The researchers say that they have demonstrated the ability to utilize the strong time-energy correlations of photon pairs for quantum-enhanced photodetection. The procedure they have presented possesses great potential for improving the performances of X-ray measurements.

Journal Reference: Physical Review X.

A comprehensive catalogue of human digestive tract bacteria

A comprehensive catalogue of human digestive tract bacteria

The human digestive tract is home to thousands of different strains of bacteria. Many of these are beneficial, while others contribute to health problems such as inflammatory bowel disease. Researchers from MIT and the Broad Institute have now isolated and preserved samples of nearly 8,000 of these strains, while also clarifying their genetic and metabolic context.

This data set (BIO-ML), which is available to other researchers who want to use it, should help to shed light on the dynamics of microbial populations in the human gut and may help scientists develop new treatments for a variety of diseases, says Eric Alm, director of MIT’s Center for Microbiome Informatics and Therapeutics and a professor of biological engineering and of civil and environmental engineering at MIT.

“There’s a lot of excitement in the microbiome field because there are associations between these bacteria and health and disease. But we’re lacking in being able to understand why that is, what’s the mechanism, and what are the functions of those bacteria that are causing them to associate with disease,” says Alm, who is the senior author of the study.

The researchers collected stool samples from about 90 people, for up to two years, allowing them to gain insight into how microbial populations change over time within individuals. This study focused on people living in the Boston area, but the research team is now gathering a larger diversity of samples from around the globe, in hopes of preserving microbial strains not found in people living in industrialized societies.

“More than ever before, modern techniques allow us to isolate previously uncultured human gut bacteria. Exploring this genetic and functional diversity is fascinating — everywhere we look, we discover new things. I’m convinced that enriching biobanks with a large diversity of strains from individuals living diverse lifestyles is essential for future advancements in human microbiome research,” says Mathilde Poyet, a senior postdoc at MIT and one of the lead authors of the study.

MIT research associate Mathieu Groussin and former postdoc Sean Gibbons are also lead authors of the study, which appears in the Sept. 2 issue of Nature Medicine. Ramnik Xavier, a professor of medicine at Harvard Medical School and member of the Broad Institute, is a senior author of the study along with Alm.

Microbiome dynamics

Humans have trillions of bacterial cells in their digestive tracts, and while scientists believe that these populations change and evolve over time, there has been little opportunity to observe this. Through the OpenBiome organization, which collects stool samples for research and therapeutic purposes, Alm and his colleagues at MIT and the Broad Institute had access to fecal samples from about 90 people.

For most of their analysis, the researchers focused on microbes found in about a dozen individuals who had provided samples over an extended period, up to two years.

“That was a unique opportunity, and we thought that would be a great set of individuals to really try to dig down and characterize the microbial populations more thoroughly,” Alm says. “To date there hadn’t been a ton of longitudinal studies, and we wanted to make that a key focus of our study, so we could understand what the variation is day-to-day.”

The researchers were able to isolate a total of 7,758 strains from the six major phyla of bacteria that dominate the human GI tract. For 3,632 of these strains, the researchers sequenced their full genomes, and they also sequenced partial genomes of the remaining strains.

Analyzing how microbial populations changed over time within single hosts allowed the researchers to discover some novel interactions between strains. In one case, the researchers found three related strains of Bacteroides vulgatus coexisting within a host, all of which appeared to have diverged from one ancestor strain within the host. In another case, one strain of Turicibacter sanguinis completely replaced a related strain of the same species nearly overnight.

“This is the first time we’re getting a glimpse of these really different dynamics,” Alm says.

Population variation

The researchers also measured the quantities of many metabolites found in the stool samples. This analysis revealed that variations in amino acid levels were closely linked with changes in microbial populations over time within a single person. However, differences between the composition of microbial populations in different people were more closely associated with varying levels of bile acids, which help with digestion.

The researchers don’t know exactly what produces these differences in amino acid and bile acid levels, but say they could be influenced by diet — a connection that they hope to investigate in future studies. They have also made all of their data available online and are offering samples of the strains of bacteria they isolated, allowing other scientists to study the functions of these strains and their potential roles in human health.

“Comprehensive and high-resolution collections of bacterial isolates open the possibility to mechanistically investigate how our lifestyle shapes our gut microbiome, metabolism, and inflammation. We aim to provide such a resource to the research community worldwide, including to lower-income research institutions,” Groussin says.

The researchers have also begun a larger-scale project to collect microbiome samples from a greater diversity of populations around the world. They are especially focusing on underrepresented populations who live in nonindustrialized societies, as their diet and microbiomes are expected to be very different from those of people living in industrialized societies.

“It may be that as populations that have been living traditional lifestyles start to switch to a more industrialized lifestyle, they may lose a lot of that biodiversity. So one of the main things we want to do is conserve it, and then later we can go back and characterize it as well,” Alm says.

Materials provided by Massachusetts Institute of Technology

Researchers find explanations behind the mystery of North Pacific gyre

Researchers find explanations behind the mystery of North Pacific gyre

The center of oceans of the Earth are covered with an enormous arrangement of rotating currents known as subtropical gyres, which occupy 40% of the Earth’s surface. They have been considered as stable biological deserts with little deviation in chemical composition or the nutrients needed to sustain life.

The region in the North Pacific Subtropical Gyre ecosystem that occupies the Pacific Ocean between China and the United States has confused scientists over the years by its strange abnormality in chemistry that changes periodically. There is a remarkable variation in the levels of phosphorus and iron which affects the entire nutrient composition and eventually biological productivity.

The research team has found out the explanation behind the variations in the North Pacific Subtropical Gyre ecosystem. It includes Matthew Church, a microbial ecologist with the University of Montana’s Flathead Lake Biological Station, Ricardo Letelier from Oregon State University and David Karl from the University of Hawaii. The work appears in the Proceedings of the National Academy of Sciences.

Church said that the variations in the ocean climate arise to basically control ocean nutrient concentrations by regulating iron supply and altering the kinds of plankton growing in these waters. He also said that after constant, long-term observations on the role of plankton in controlling ocean nutrient availability, their team has finally confirmed that tightly linked plankton supplies nutrients, particularly iron, delivered from the atmosphere.

With the help of three decades of observational data from Station ALOHA, a six-mile area in the Pacific Ocean, the researchers discovered that the periodic shift in the level of iron is due to iron input from Asian dust, accounting for the chemical variances and varying amounts of nutrients to sustain life.

The ocean-atmosphere relationship known as The Pacific Decadal Oscillation varies between weak and strong stages of atmospheric pressure in the northeast Pacific Ocean which is the major factor of the variance. The winds from Asia become stronger and move in a more southern direction in years when the low pressure weakens in the northeast Pacific bringing more dust from Asia and fertilizing the ocean around ALOHA. The opposite occurs when the pressure strengthens.

Phosphorous and iron are the essential components of life and the supply of nutrients is a fundamental controller of ocean productivity. The process of fertilizing the ocean’s upper water level by mixing nutrient-rich water from the bottom is challenging in the North Pacific Subtropical Gyre ecosystem because the waters are very layered and very less mixing takes place. The creatures are allowed to grow and use phosphorus in the upper layers of the ocean when strong Asian winds bring in substantial quantity of iron while they are forced to return to a bottom-water-mixing nutrient delivery system when the Asian winds weaken and iron quantity is reduced creating the periodic ebb and flow of iron and phosphorus levels in the North Pacific Gyre.

Church said that the results from the study highlight the crucial need to include both atmospheric and ocean circulation variability for forecasting the climate change impact on ocean ecosystems. He also added that it confirms the necessity to think about the biology of tightly connected plankton to changes in climate as well as land use which can directly impact dust supply to the ocean.

Researchers hope to see long-term changes in wind patterns across the North Pacific as Earth’s temperature continues to increase. The sources and quantity of iron and other nutrients carried by the wind across the ocean will get affected by the evolution of land use and pollution caused by human activity in Asia.

To know the impact of the changes on ecosystems around the ocean region as well as others around the world, more research is needed.

Journal Reference: Proceedings of the National Academy of Sciences.

Researchers observe human like brain waves in lab grown mini brains

Researchers observe human-like brain waves in lab-grown mini-brains

One method by which researchers can non-invasively analyze the human brain is by developing pea-sized clusters of brain cells called “mini-brains” in the research lab. This week, the team announced that they found human-like brainwaves from these organoids in a magnificent advancement of this field of research.

The movement and nerve tract development of mini-brains has been shown by the previous studies. Biologist Alysson Muotri along with the researchers at the University of California San Diego are the first to study and record human-like neural activity. The researchers wrote that they observed brain wave patterns similar to those of a developing human in their paper published in Cell Stem Cell. Muotri said that sophistication in the in vitro model is a step to help researchers to use mini-brains to study brain development, model diseases, and study about the evolution of the brain. Researchers are good at studying cancer and the heart but the brain has been behind the curve.

Researchers introduced pluripotent human stem cells to a nutrient-rich petri-dish intended to imitate the environment in which our own brains develop to create the technical “mini-brains” called organoids. These cells could be stimulated into building a 3D structure similar to the much smaller human brain because of the multipotential (potential to become any number of different cells) nature of the stem cells. The researchers started to observe the peak of neural activity from the network at around two months of development.

Co-author and Ph.D. student Richard Gao stated that at the beginning, they weren’t checking for parallels between their model and human infant when they began to observe these intermittent bursts of electrical activity. Gao said that they observed a notable feature in organoid oscillations that the network is inactive most of the time and explode spontaneously in every 10-20 seconds. This also occurs in preterm infants called trace discontinu where strong oscillatory transients emphasize the infant’s inactive ECG. He also said that we are very lucky to find a dataset reporting these features in the preterm infant EEG at a point where oscillations vary.

Muotri said that a machine learning algorithm has been prepared by the team to identify important features in the preterm infant EEGs and had it evaluate the cerebral organoids for similarities. It was able to calculate how many weeks the organoids had developed in the culture and could no more distinguish between the organoids and the infant EEGs between 25 and 40 weeks of the organoid’s development.

Muotri and the team clarified that the comparison between the two is not necessarily one-to-one and preterm infant EEGs have some limitations including the impact the thickness of a developing human skull has on readings which differ from the lab-produced organoids.

Arnold Kriegstein, a neurologist from the University of California, San Francisco, who did not contribute to the new study, said that it is difficult to state similarity between organoid activity and preterm EEG. The researchers have clearly shown the development of spontaneous activity in organoids to be reliable on the neuronal activity but organoids are very different from the actual developing cortex and we still need better evidence that the underlying mechanisms are the same even if the phenomenology is similar.

Muotri said that he can’t be sure whether the organoids were developed enough to be considered conscious and questions related to ethical dilemmas might be raised in the future. He intends to hold a meeting at UC San Diego with scientists, philosophers, and ethicists to talk about the ethical future of such technologies. He said that his tendency is always to say that technologies like blood transfusions or organ transplants, or even cars can be used for good as well as bad so brain organoids might also point in a similar direction in the future.

Journal Reference: Cell Stem Cell

A new drug could revolutionize the treatment of neurological disorders

A new drug could revolutionize the treatment of neurological disorders

The international team of scientists from Gero Discovery LLC, the Institute of Biomedical Research of Salamanca, and Nanosyn, Inc. has found a potential drug that may prevent neuronal death through glucose metabolism modification in stressed neurons. The positive results obtained in mice are rather promising for future use in humans. The new drug can be advantageous in neurological conditions ranging from Amyotrophic lateral sclerosis, Alzheimer’s, and Huntington’s diseases to traumatic brain injury and ischemic stroke. The results have been published in the Scientific Reports Journal.

Brain injuries of different nature and neurological disorders are among the most important causes of death worldwide. According to WHO, stroke is the second most common cause of mortality, and more than a third of people who have survived a stroke will have a severe disability.

What is more, as the population ages, millions of more people are posed to develop Alzheimer’s or Parkinson’s diseases in the near future. However, there are no efficient drugs for major neurodegenerative diseases. It is thus critically important to understand the biology of these diseases and to identify new drugs capable of improving quality of life, survival, and,  in the best-case scenario, curing the disease completely.

Glycolysis is generally considered as the metabolic pathway essential for cell survival since it meets cell energy needs in case of intensive energy consumption. However, it is already known that in the brain tissue, the situation is quite different – different cell types show distinct glucose metabolism patterns.  In neurons, only a small portion of glucose is consumed via the glycolysis pathway. At the same time, astrocytes provide nutrients to neurons and utilize glycolysis to metabolize glucose. These differences are mostly due to the special protein called PFKFB3, which is normally absent in neurons and is active in astrocytes. In the case of certain neurological diseases, stroke being one of them, the amount of active PFKFB3 increases in neurons, which is highly stressful for these cells and leads to cell death.

An international team of researchers led by Peter Fedichev, a scientist and biotech entrepreneur from Gero Discovery, and professor Juan P. Bolaños from the University of Salamanca, suggested and further confirmed in the in vivo experiments that a small molecule, the inhibitor of PFKFB3, may prevent cell death in the case of ischemia injury. Inhibition of PFKFB3 improves motor coordination of mice after stroke and reduced brain infarct volume. Moreover, in the experiments using mouse cell cultures, it was shown that PFKFB3 inhibitor protects neurons from the amyloid-beta peptide, the main component of the amyloid plaques found in the brains of Alzheimer’s disease patients.

Professor Juan P. Bolaños: “Excitotoxicity is a hallmark of various neurological diseases, stroke being one of them. Our group has previously established a link between this pathological condition and high activity of PFKFB3 enzyme in neurons, which leads to severe oxidative stress and neuronal death“

“We are glad that our hypothesis that pharmacological inhibition of  PFKFB3 can be beneficial in an excitotoxicity-related condition, such as stroke was confirmed. I would like to note that In our work, we used a known molecule to demonstrate that PFKFB3 blockage has a therapeutic effect. But, we have also performed the same experiments with other proprietary small molecule designed in our company and showed that it had a similar effect. There is, of course, still much work to do. We are currently investigating the efficacy of our compounds in the models of orphan excitotoxicity-related neurological diseases. We have already obtained good safety results in mice and believe that we will be successful in our future investigations” said Olga Burmistrova, Director of preclinical development in Gero Discovery.

Gero Discovery team is planning to proceed with preclinical trials and to move into clinical trials soon. “These promising results bring hope to dozens of millions of patients suffering from life-threatening neurological diseases and provide tremendous business opportunities in many indications with unmet needs. We start communicating with potential investors and co-development partners and invite interested parties to collaborate on the further development of this breakthrough medicine through the preclinical and early clinical stage” mentioned Maksim Kholin, the Gero Discovery Co-Founder and Business Development Director.

Journal Reference: Scientific Reports Journal

Northern White Rhinoceros Angalifu

Scientists fertilise 7 eggs of northern white rhino in an effort to save the species

As Silvia Colleoni injected liquid into a micropipette for inserting the frozen sperm which had been removed from one of the last remaining male northern white rhinos, her hand trembled. She explained the cause of being emotional as it is a manual task and her work could determine if the species would continue to live or get extinct. The artificial fertilization of eggs from the last two remaining females was performed in the Avantea Laboratory in North Italy. The fertilisation process could result in the creation of seven embryos. 

The entire procedure was filmed by the Associated Press who had exclusive access to the laboratory. Eggs were separated from the last remaining female northern white rhinos, Fatu and Najin. Then they were fertilised from the frozen sperms separated from males who were already dead. After 10 days, the result will be out if embryos were formed from the eggs or not. Experts are hoping for the reproduction to be carried through surrogacy as neither of the two females can get pregnant now. 

The process is very strenuous and involves a lot of concentration as joysticks are used to guide the process of fertilisation. For increasing the chances of success, an electronic impulse is also sent. Cesare Galli, founder of Avantea said that they expect for the formation of embryos from some of them as the ultimate goal is to produce a minimum of five animals who would be returned to their natural habitat in Africa. But achieving this could take several decades. 

Avantea reported that only seven from ten eggs which were extracted from the females in Kenya were fit for the process of artificial insemination. The sperm was extracted from northern white bulls, Suni and Saut who lived in a Czech Republic zoo. They are now dead. Their sperm was used to increase the chances of success, as Suni is the half-sibling of Najin. However, it was difficult to work with Saut’s sperm. Galli stated that for greater chances to facilitate the continuation of a species it is better not to wait till the last two individuals of a species are remaining. The last living male rhino was 45-year-old Sudan who was listed in the dating app Tinder and mentioned the “Most Eligible Bachelor” in an attempt to raise funds. However, he was later euthanized for age-related complications. 

His sperm is still in Kenya, as in the future if it is possible to create more embryos then his sperm could be transferred. Northern white rhinos have decreased in population due to excessive poaching for several decades. Other types such as southern white rhino and black rhino are also targeted for their horns which are sold illegally in Asian markets. 

Leibniz Institute for Zoo and Wildlife Research situated in Germany, Avantea, Dvur Kralove Zoo in Czech Republic are some of the organisations trying to save the northern white rhino species. 

anatomy of brain

Researchers figure out why we remember some incidents for a long time and forget some

It often happens that we can remember something which occurred long back but forget the incident that took place recently. Some memories remain stable while others fade away in minutes.

Researchers from Caltech have found that the memories which remain stable over time are encoded by a group of neurons firing in synchrony thus providing redundancy. The work also tries to understand the effects on memory after tragic events such as brain damage or Alzheimer’s disease.

The experiments were carried out in the laboratory of Carlos Lois, a biology professor and affiliated faculty member of Tianqiao and Chrissy Chen Institute for Neuroscience. It appears in the Science journal.

The team was led by Walter Gonzalez, a postdoc scholar. A test was developed for testing the neural activity of mice when they learn and remember a new place. The mouse was kept in a straight enclosure of length 5 feet. Different symbols were marked in different locations on the walls such as a bold plus sign at the rightmost end and angled slash close to the center. Sugar water was placed at the track ends. As the mouse explored places, the activities of certain neurons in the hippocampus were tracked by the scientists.

When initially placed in the track, the mouse wandered till it found the sugar water. Single neurons were activated when it spotted a symbol on the wall. However, on staying longer, the mouse remembered the sugar locations. As the familiarity increased more neurons got activated in synchrony as it spotted the symbols.

To understand the fading of memories, the mice were kept away from the track for 20 days. On getting back to the track, the mice which had strong memories encoded by high numbers of neurons remembered the task easily. So when large groups of neurons encode an activity, the memories can be easily recalled even if some showed different activity or remained silent.

This can be explained in a way similar to how a long story is remembered. For remembering a long story, it can be told to many different people and when all of them gather each can fill in the gaps which the other member has forgotten. By repeating this every time, the story can be preserved with the strengthening of the memory. In a similar way, neurons help each other in encoding memories which stay over time.

Impairment of memory in any form can affect us a lot since our life is basically driven by memories. Senior citizens get affected by this as a part of the aging process. Alzheimer’s disease also has devastating effects which paralyze even the basic daily functioning of a person. When memory is encoded by fewer neurons it can be forgotten easily. As a result of this, treatments which increase the recruitment of a large number of neurons for encoding a memory help in preventing memory loss.

When an activity is practiced a lot, there are more chances of remembering it as more neurons are encoded for the action. It is usually considered that to make a memory stable, individual connections to a neuron have to be strengthened. However, the study suggests that the memory can be stored for a long period of time with an increase in the neurons which encode it.

Research Paper: Persistence of neuronal representations through time and damage in the hippocampus

Monkey and Human Skulls

Tiny skull fossil indicates the separate evolution of primate brain areas

A 20 million-year-old monkey skull which can fit in the palm of an adult’s hand may contain clues to the evolution of the brain in ancient primates.

A study has found that the neural landmarks on the skull depict a situation in which certain primate brain regions expanded or contracted independent of other regions. According to researchers, a section of the monkey’s brain involved with perception of smell was not balanced with a visual system of greater size, as present in the primates currently.

Xijun Ni, paleontologist of Chinese Academy of Sciences, Beijing said that the size and complexity of the primate visual systems increased through several million years without major changes in the other sections of the brain. By comparing with the skulls of the fossils belonging to African primates aged more than 30 million years it is revealed that brain structures evolved at different rates in different lineages along with the change in brain size with that of body. The work appears in the Science Advances journal. This shows that the brain of primates did not just expand as a whole but different sections changed at different rates.

An extinct monkey’s skull, Chilecebus carrascoensis was discovered in Andes Mountains, Chile in 1995 by John Flynn, a paleontologist at American Museum of Natural History, New York. They used high-resolution scanning and a three-dimensional cast of the skull’s inner surface to obtain impressions made by neural folds.

It revealed that brain tissue was separated into different areas with specific duties like smell and vision. Estimation of the size of the ancient visual system was done through measuring the eye sockets in the skull and an opening present at the back of the cavities. Placement of key folds on the surface of the brain helped in estimating the size of the region dedicated to smell perception.

Brenda Benefit, a biological anthropologist at New Mexico State University said that the variety of folding patterns of the brain in New World monkeys exceed that of the patterns in the brains of present-day African and Asian monkeys. But their features are not always relevant to the study of ape brain evolution and Old World monkey.

Previously her team identified a 15 million-year-old African monkey which had a large odor-perception region in a brain of a smaller size similar to today’s African monkeys.

Ni said that through comparing fossils of Old World and New World monkeys, they found that through different means of evolution, a gradual increase in the complexity and size of brain were produced.

We're One Step Closer to a Blood Test that Predicts When a Person Will Die

Researchers are close to blood tests which can estimate mortality risks

In life, there are two inevitable things. Death and taxes. For the first one, scientists have been trying to come up with a test which can help in estimating their mortality. It would check their current health status and then calculate how they might be vulnerable to mortality risk factors. For this purpose, blood tests are most preferred as blood samples can be easily obtained and there are enough labs for handling them. 

This effort is described in a paper which appears in the journal Nature Communications. The team is led by Joris Deelen, a postdoc researcher at the Max Planck Institute for the Biology of Aging and P. Eline Slagboom, molecular epidemiology head, Leiden University Medical Center. Scientists reported that from 44000 healthy patients, an accuracy of 80% in determining mortality risk was achieved through the blood tests. 

Age of the patients varied from 18 to 109 years. They provided their blood samples and their health conditions were tracked till 16 years. A group of 226 metabolites (which are cell and tissue discharges into the blood) were analysed. From this, 14 were chosen which combined with the gender of the person could provide their health risks and possibilities of death in five to ten years. This was done by comparing those who died in the course of study to the ones who did not and separating the elements in the blood which differed significantly. There is a strong correlation between the 14 factors and mortality even after considering factors such as age, sex and death cause. 

Slagboom said that they wanted to account for the vulnerability of the human body which cannot be observed by doctors. Researchers are amazed by the fact that a blood sample at any point of a person’s life can predict the possibilities of any risks in the next five to ten years.

This is not yet ready for application with patients but it provides a solid foundation for future research. A more refined version of the test would be most useful for older patients in helping with their treatment as the 14 metabolites represent processes such as fat and glucose breakdown, body fluid balance which can affect ailments as well as the ability of a person to recover from an injury.

Real-life examples are being studied where researchers are working on chances of recovery of a person undergoing hip surgery and possibilities of side effects such as dementia or delirium after treatment of kidney failure. Scientists are working on large databanks to confirm their results as this only lies the base of the future works. 

Journal Reference: Nature Communications

Skeletons in Roopkund Lake

DNA analysis of the Roopkund skeletons makes its mystery even more complex

Roopkund lake amidst the Himalayan mountains has been a place of mystery. It is a shallow lake which is filled with the bones of human beings, due to which it is also known as Skeleton Lake and the reason behind the presence of skeletons is not yet known. 

One hypothesis is that a large number of people died due to a single catastrophe. However, this idea is now challenged by DNA analysis of 38 skeletons present there. It reveals that different groups of people from distant places such as the Mediterranean came to the lake over a period of 1000 years. The paper appears in the journal Nature Communications

David Reich, a geneticist from Harvard Medical School said that biomolecular analysis including radiocarbon dating and stable isotope dietary reconstruction reveals the history of the lake to be more complex than imagined. Geneticist Kumarasamy Thangaraj, CSIR Centre for Cellular and Molecular Biology sequenced mitochondrial DNA of 72 skeletons a decade ago. Some skeletons had DNA of a local Indian origin however several appeared to have come from West Eurasia. This led to a deeper analysis of genome sequencing in which genome-wide DNA was produced for 38 persons. These were compared against 1521 ancient and 7985 current persons from all over the world. 23 persons had similar DNA to that of people from India however 14 persons had similar DNA to that of residents in current Greece and Crete. And one person had DNA from Southeast Asian origin. 

Eadaoin Harney, Harvard University said that scientists are highly surprised by this variation in the genetics of the skeletons. That the DNAs of the skeletons reveal similarities with the eastern Mediterranean suggests that the Lake attracted visitors from all over the world. Isotope analysis supports these findings. Some stable isotopes can be absorbed in plants which are then eaten by people. These replace some calcium in bones and teeth which can be matched suitably to specific locations. 

Ayushi Nayak, archaeologist of Max Planck Institute for Science of Human History said that persons with Indian origins had a diet mainly depending on C3 and C4 derived food sources. It is consistent with the genetic evidence that they belonged to several socioeconomic groups in South Asia. However, people connected to the eastern Mediterranean had a diet with a lesser amount of millet. 

What is even more mind-boggling is the time of arrival of these groups. Radiocarbon dating estimates that the bones related to Indian ancestry came between the 7th and 10th centuries and those from the Mediterranean and Southeast Asia were dated between the 17th and 20th centuries. It is very much possible that skeletons not tested could belong to other regions from different time periods.

We still do not know how these persons came to the Lake and what is the cause of their death. Scientists have to dig deeper to find the answers. 

Journal Reference: Nature Communications