For the first time in the history of space exploration, scientists have measured the seasonal changes in the gases that fill the air directly above the surface of Gale Crater on Mars. As a result, they noticed something baffling: oxygen, the gas many Earth creatures use to breathe, behaves in a way that so far scientists cannot explain through any known chemical processes.
Over the course of three Mars years (or nearly six Earth years) an instrument in the Sample Analysis at Mars (SAM) portable chemistry lab inside the belly of NASA's Curiosity rover inhaled the air of Gale Crater and analyzed its composition. The results SAM spit out confirmed the makeup of the Martian atmosphere at the surface: 95% by volume of carbon dioxide (CO2), 2.6% molecular nitrogen (N2), 1.9% argon (Ar), 0.16% molecular oxygen (O2), and 0.06% carbon monoxide (CO). They also revealed how the molecules in the Martian air mix and circulate with the changes in air pressure throughout the year. These changes are caused when CO2 gas freezes over the poles in the winter, thereby lowering the air pressure across the planet following redistribution of air to maintain pressure equilibrium. When CO2 evaporates in the spring and summer and mixes across Mars, it raises the air pressure.
Within this environment, scientists found that nitrogen and argon follow a predictable seasonal pattern, waxing and waning in concentration in Gale Crater throughout the year relative to how much CO2 is in the air. They expected oxygen to do the same. But it didn't. Instead, the amount of the gas in the air rose throughout spring and summer by as much as 30%, and then dropped back to levels predicted by known chemistry in fall. This pattern repeated each spring, though the amount of oxygen added to the atmosphere varied, implying that something was producing it and then taking it away.
"The first time we saw that, it was just mind boggling," said Sushil Atreya, professor of climate and space sciences at the University of Michigan in Ann Arbor. Atreya is a co-author of a paper on this topic published on November 12 in the Journal of Geophysical Research: Planets.
As soon as scientists discovered the oxygen enigma, Mars experts set to work trying to explain it. They first double- and triple-checked the accuracy of the SAM instrument they used to measure the gases: the Quadrupole Mass Spectrometer. The instrument was fine. They considered the possibility that CO2 or water (H2O) molecules could have released oxygen when they broke apart in the atmosphere, leading to the short-lived rise. But it would take five times more water above Mars to produce the extra oxygen, and CO2 breaks up too slowly to generate it over such a short time. What about the oxygen decrease? Could solar radiation have broken up oxygen molecules into two atoms that blew away into space? No, scientists concluded, since it would take at least 10 years for the oxygen to disappear through this process.
"We're struggling to explain this," said Melissa Trainer, a planetary scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland who led this research. "The fact that the oxygen behavior isn't perfectly repeatable every season makes us think that it's not an issue that has to do with atmospheric dynamics. It has to be some chemical source and sink that we can't yet account for."
To scientists who study Mars, the oxygen story is curiously similar to that of methane. Methane is constantly in the air inside Gale Crater in such small quantities (0.00000004% on average) that it's barely discernable even by the most sensitive instruments on Mars. Still, it's been measured by SAM's Tunable Laser Spectrometer. The instrument revealed that while methane rises and falls seasonally, it increases in abundance by about 60% in summer months for inexplicable reasons. (In fact, methane also spikes randomly and dramatically. Scientists are trying to figure out why.)
With the new oxygen findings in hand, Trainer's team is wondering if chemistry similar to what's driving methane's natural seasonal variations may also drive oxygen's. At least occasionally, the two gases appear to fluctuate in tandem.
"We're beginning to see this tantalizing correlation between methane and oxygen for a good part of the Mars year," Atreya said. "I think there's something to it. I just don't have the answers yet. Nobody does."
Oxygen and methane can be produced both biologically (from microbes, for instance) and abiotically (from chemistry related to water and rocks). Scientists are considering all options, although they don't have any convincing evidence of biological activity on Mars. Curiosity doesn't have instruments that can definitively say whether the source of the methane or oxygen on Mars is biological or geological. Scientists expect that non-biological explanations are more likely and are working diligently to fully understand them.
Trainer's team considered Martian soil as a source of the extra springtime oxygen. After all, it's known to be rich in the element, in the form of compounds such as hydrogen peroxide and perchlorates. One experiment on the Viking landers showed decades ago that heat and humidity could release oxygen from Martian soil. But that experiment took place in conditions quite different from the Martian spring environment, and it doesn't explain the oxygen drop, among other problems. Other possible explanations also don't quite add up for now. For example, high-energy radiation of the soil could produce extra O2 in the air, but it would take a million years to accumulate enough oxygen in the soil to account for the boost measured in only one spring, the researchers report in their paper.
"We have not been able to come up with one process yet that produces the amount of oxygen we need, but we think it has to be something in the surface soil that changes seasonally because there aren't enough available oxygen atoms in the atmosphere to create the behavior we see," said Timothy McConnochie, assistant research scientist at the University of Maryland in College Park and another co-author of the paper.
The only previous spacecraft with instruments capable of measuring the composition of the Martian air near the ground were NASA's twin Viking landers, which arrived on the planet in 1976. The Viking experiments covered only a few Martian days, though, so they couldn't reveal seasonal patterns of the different gases. The new SAM measurements are the first to do so. The SAM team will continue to measure atmospheric gases so scientists can gather more detailed data throughout each season. In the meantime, Trainer and her team hope that other Mars experts will work to solve the oxygen mystery.
Read more at Science Daily
Nov 12, 2019
Good noise, bad noise: White noise improves hearing
Noise is not the same as noise -- and even a quiet environment does not have the same effect as white noise. With a background of continuous white noise, hearing pure sounds becomes even more precise, as researchers from the University of Basel have shown in a study in Cell Reports. Their findings could be applied to the further development of cochlear implants.
Despite the importance of hearing in human communication, we still understand very little of how acoustic signals are perceived and how they are processed to allow us to make sense of them. One thing is clear though: the more precisely we can distinguish sound patterns, the better our hearing is. But how does the brain manage to distinguish between relevant and less relevant information -- especially in an environment with background noise?
Exploring the "auditory brain"
Researchers led by Prof. Dr. Tania Rinaldi Barkat from the Department of Biomedicine at the University of Basel have investigated the neuronal foundation of sound perception and sound discrimination in a challenging sound environment. The focus was on research into the auditory cortex -- the "auditory brain," that is, the area of the brain that processes acoustic stimuli. The resulting activity patterns stem from measurements in a mouse brain.
As is well known, the distinction between sounds becomes more difficult the closer they are in the frequency spectrum. Initially, the researchers assumed that additional noise could make such a hearing task even more difficult. However, the opposite was observed: The team was able to demonstrate that the brain's ability to distinguish subtle tone differences improved when white noise was added to the background. Compared to a quiet environment, the noise thus facilitated auditory perception.
Noise reduces neuronal activity
The data of the research group showed that white noise significantly inhibited the activity of the nerve cells in the auditory cortex. Paradoxically, this suppression of the neuronal excitation led to a more precise perception of the pure tones. "We found that less overlap occurred between populations of neurons during two separate tone representations," explains Professor Tania Barkat. "As a result, the overall reduction in neuronal activity produced a more distinct tone representation."
Read more at Science Daily
Despite the importance of hearing in human communication, we still understand very little of how acoustic signals are perceived and how they are processed to allow us to make sense of them. One thing is clear though: the more precisely we can distinguish sound patterns, the better our hearing is. But how does the brain manage to distinguish between relevant and less relevant information -- especially in an environment with background noise?
Exploring the "auditory brain"
Researchers led by Prof. Dr. Tania Rinaldi Barkat from the Department of Biomedicine at the University of Basel have investigated the neuronal foundation of sound perception and sound discrimination in a challenging sound environment. The focus was on research into the auditory cortex -- the "auditory brain," that is, the area of the brain that processes acoustic stimuli. The resulting activity patterns stem from measurements in a mouse brain.
As is well known, the distinction between sounds becomes more difficult the closer they are in the frequency spectrum. Initially, the researchers assumed that additional noise could make such a hearing task even more difficult. However, the opposite was observed: The team was able to demonstrate that the brain's ability to distinguish subtle tone differences improved when white noise was added to the background. Compared to a quiet environment, the noise thus facilitated auditory perception.
Noise reduces neuronal activity
The data of the research group showed that white noise significantly inhibited the activity of the nerve cells in the auditory cortex. Paradoxically, this suppression of the neuronal excitation led to a more precise perception of the pure tones. "We found that less overlap occurred between populations of neurons during two separate tone representations," explains Professor Tania Barkat. "As a result, the overall reduction in neuronal activity produced a more distinct tone representation."
Read more at Science Daily
Bacteria may contribute more to climate change as planet heats up
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| Salt lake at Coorong National Park, South Australia. |
By releasing more carbon as global temperatures rise, bacteria and related organisms called archaea could increase climate warming at a faster rate than current models suggest. The new research, published today in Nature Communications by scientists from Imperial College London, could help inform more accurate models of future climate warming.
Bacteria and archaea, collectively known as prokaryotes, are present on every continent and make up around half of global biomass -- the total weight of all organisms on Earth.
Most prokaryotes perform respiration that uses energy and releases carbon dioxide -- just like we do when we breathe out. The amount of carbon dioxide released during a given time period depends on the prokaryote's respiration rate, which can change in response to temperature.
However, the exact relationship between temperature, respiration rate and carbon output has been uncertain. Now, by bringing together a database of respiration rate changes according to temperature from 482 prokaryotes, researchers have found the majority will increase their carbon output in response to higher temperatures to a greater degree than previously thought.
Lead researcher Dr Samraat Pawar, from the Department of Life Sciences at Imperial, said: "In the short term, on a scale of days to hours, individual prokaryotes will increase their metabolism and produce more carbon dioxide. However, there is still a maximum temperature at which their metabolism becomes inefficient.
"In the longer term, over years, these prokaryote communities will evolve to be more efficient at higher temperatures, allowing them to further increase their metabolism and their carbon output.
"Rising temperatures therefore cause a 'double whammy' effect on many prokaryote communities, allowing them to function more efficiently in both the short and long term, and creating an even larger contribution to global carbon and resulting temperatures."
The researchers compiled prokaryote responses to temperature changes from across the world and in all different conditions -- from salty Antarctic lakes below 0°C to thermal pools above 120°C.
They found that prokaryotes that usually operate in a medium temperature range -- below 45°C -- show a strong response to changing temperature, increasing their respiration in both the short term (days to weeks) and long term (months to years).
Prokaryotes that operate in higher temperature ranges -- above 45°C -- did not show such a response, but since they operate at such high temperatures to begin with, they are unlikely to be impacted by climate change.
The short-term responses of medium-temperature prokaryotes to warming were larger than those reported for eukaryotes -- organisms with more complex cells, including all plants, fungi and animals.
The team built a mathematical model that predicted how these respiration rate changes would affect the carbon output of prokaryote communities. This revealed that short- and long-term changes to respiration rate would combine to create a larger-than-expected rise in carbon output, which is currently unaccounted for in ecosystem and climate models.
Lead author of the new research, PhD student Thomas Smith from the Department of Life Sciences, said: "Most climate models assume that all organisms' respiration rates respond to temperature in the same way, but our study shows that bacteria and archaea are likely to depart from the 'global average'.
"Given that these micro-organisms are likely to be significant contributors to total respiration and carbon output in many ecosystems, it's important for climate models to take into account their higher sensitivity to temperature change at both short and long timescales.
Read more at Science Daily
Specific neurons that map memories now identified in the human brain
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| Brain-map overlay concept illustration. |
Studies have shown that declarative memory -- the kind of memory you can consciously recall like your home address or your mother's name -- relies on healthy medial temporal lobe structures in the brain, including the hippocampus and entorhinal cortex (EC). These regions are also important for spatial cognition, demonstrated? by the Nobel-Prize-winning discovery of "place cells" and "grid cells" in these regions -- neurons that activate to represent specific locations in the environment during navigation (akin to a GPS). However, it has not been clear if or how this "spatial map" in the brain relates to a person's memory of events at those locations, and how neuronal activity in these regions enables us to target a particular memory for retrieval among related experiences.
A team led by neuroengineers at Columbia Engineering has found the first evidence that individual neurons in the human brain target specific memories during recall. They studied recordings in neurosurgical patients who had electrodes implanted in their brains and examined how the patients' brain signals corresponded to their behavior while performing a virtual-reality (VR) object-location memory task. The researchers identified "memory-trace cells" whose activity was spatially tuned to the location where subjects remembered encountering specific objects. The study is published today in Nature Neuroscience.
"We found these memory-trace neurons primarily in the entorhinal cortex (EC), which is one of the first regions of the brain affected by the onset of Alzheimer 's disease," says Joshua Jacobs, associate professor of biomedical engineering, who directed the study. "Because the activity of these neurons is closely related to what a person is trying to remember, it is possible that their activity is disrupted by diseases like Alzheimer's, leading to memory deficits. Our findings should open up new lines of investigation into how neural activity in the entorhinal cortex and medial temporal lobe helps us target past events for recall, and more generally how space and memory overlap in the brain."
The team was able to measure the activity of single neurons by taking advantage of a rare opportunity: invasively recording from the brains of 19 neurosurgical patients at several hospitals, including the Columbia University Irving Medical Center. The patients had drug-resistant epilepsy and so had already had recording electrodes implanted in their brains for their clinical treatment. The researchers designed experiments as engaging and immersive VR computer games and the bedridden patients used laptops and handheld controllers to move through virtual environments. In performing the task, subjects first navigated through the environment to learn the locations of four unique objects. Then the researchers removed the objects and asked patients to move through the environment and mark the location of one specific object on each trial.
The team measured the activity of neurons as the patients moved through the environment and marked their memory targets. Initially, they identified purely spatially tuned neurons similar to "place cells" that always activated when patients moved through specific locations, regardless of the subjects' memory target. "These neurons seemed only to care about the person's spatial location, like a pure GPS," says Salman E. Qasim, Jacobs' PhD student and lead author of the study.
But the researchers also noticed that other neurons only activated in locations relevant to the memory the patient was recalling on that trial -- whenever patients were instructed to target a different memory for recall, these neurons changed their activity to match the new target's remembered location. What especially excited Jacobs and Qasim is that they could actually decode the specific memory a patient was targeting based on the activity of these neurons.
"Our study demonstrates that neurons in the human brain track the experiences we are willfully recalling, and can change their activity patterns to differentiate between memories. They're just like the pins on your Google map that mark the locations you remember for important events," Qasim says. "This discovery might provide a potential mechanism for our ability to selectively call upon different experiences from the past and highlights how these memories may influence our brain's spatial map."
Read more at Science Daily
Nov 11, 2019
Ancient gas cloud reveals universe's first stars formed quickly
The discovery of a 13 billion-year-old cosmic cloud of gas enabled a team of Carnegie astronomers to perform the earliest-ever measurement of how the universe was enriched with a diversity of chemical elements. Their findings reveal that the first generation of stars formed more quickly than previously thought. The research, led by recent Carnegie-Princeton fellow Eduardo Bañados and including the Carnegie's Michael Rauch and Tom Cooper, is published by the Astrophysical Journal.
The Big Bang started the universe as a hot, murky soup of extremely energetic particles that was rapidly expanding. As this material spread out, it cooled, and the particles coalesced into neutral hydrogen gas. The universe stayed dark, without any luminous sources, until gravity condensed matter into the first stars and galaxies.
All stars, including this first generation, act as chemical factories, synthesizing almost all of the elements that make up the world around us. When the original stars exploded as supernovae, they spewed out the elements that they created, seeding the surrounding gas. Subsequent generations of stars incorporated these elements and steadily increased the chemical abundances of their surroundings.
But the first stars formed in a still pristine, cold universe. Consequently these initial stars produced elements in different proportions than those synthesized by younger stars, which were formed in an environment that was already enriched by earlier generations.
"Looking back in time far enough, one may expect cosmic gas clouds to show the tell-tale signature of the peculiar element ratios made by the first stars," said Rauch. "Peering even further back, we may ultimately witness the disappearance of most elements and the emergence of pristine gas."
Astronomers have long used quasars to learn about the chemical composition of cosmic gas over time, showing how different generations of stars enrich their surroundings.
"We found this ancient gas cloud when following up on an inventory of very distant quasars using the Magellan telescopes at Carnegie's Las Campanas Observatory in Chile," explained Bañados, who is now a group leader at the Max-Planck Institute in Heidelberg.
Quasars are tremendously luminous objects comprised of enormous black holes accreting matter at the centers of massive galaxies. Because the gas cloud exists between the quasar and us on Earth, the quasar's incredibly bright light must pass through it to get to us and astronomers can take advantage of this to understand the cloud's chemistry. This discovery presented an unprecedented opportunity to characterize a gas cloud from the first billion years of cosmic history.
The team found that the cloud's chemical makeup was quite modern, and not as primitive as expected if dominated by the first stars. Although it formed only 850 million years after the Big Bang, its chemical abundances were already as high as those typically seen in cosmic gas clouds that were formed several billion years later.
"Apparently, the first generation of stars had already expired by the time the cloud formed," Rauch explained. "This shows that the universe was rapidly swamped by the chemical products of later generations of stars, even before most of the present-day galaxies were in place."
Read more at Science Daily
The Big Bang started the universe as a hot, murky soup of extremely energetic particles that was rapidly expanding. As this material spread out, it cooled, and the particles coalesced into neutral hydrogen gas. The universe stayed dark, without any luminous sources, until gravity condensed matter into the first stars and galaxies.
All stars, including this first generation, act as chemical factories, synthesizing almost all of the elements that make up the world around us. When the original stars exploded as supernovae, they spewed out the elements that they created, seeding the surrounding gas. Subsequent generations of stars incorporated these elements and steadily increased the chemical abundances of their surroundings.
But the first stars formed in a still pristine, cold universe. Consequently these initial stars produced elements in different proportions than those synthesized by younger stars, which were formed in an environment that was already enriched by earlier generations.
"Looking back in time far enough, one may expect cosmic gas clouds to show the tell-tale signature of the peculiar element ratios made by the first stars," said Rauch. "Peering even further back, we may ultimately witness the disappearance of most elements and the emergence of pristine gas."
Astronomers have long used quasars to learn about the chemical composition of cosmic gas over time, showing how different generations of stars enrich their surroundings.
"We found this ancient gas cloud when following up on an inventory of very distant quasars using the Magellan telescopes at Carnegie's Las Campanas Observatory in Chile," explained Bañados, who is now a group leader at the Max-Planck Institute in Heidelberg.
Quasars are tremendously luminous objects comprised of enormous black holes accreting matter at the centers of massive galaxies. Because the gas cloud exists between the quasar and us on Earth, the quasar's incredibly bright light must pass through it to get to us and astronomers can take advantage of this to understand the cloud's chemistry. This discovery presented an unprecedented opportunity to characterize a gas cloud from the first billion years of cosmic history.
The team found that the cloud's chemical makeup was quite modern, and not as primitive as expected if dominated by the first stars. Although it formed only 850 million years after the Big Bang, its chemical abundances were already as high as those typically seen in cosmic gas clouds that were formed several billion years later.
"Apparently, the first generation of stars had already expired by the time the cloud formed," Rauch explained. "This shows that the universe was rapidly swamped by the chemical products of later generations of stars, even before most of the present-day galaxies were in place."
Read more at Science Daily
Free Internet access should be a basic human right: Study
Free internet access must be considered as a human right, as people unable to get online -- particularly in developing countries -- lack meaningful ways to influence the global players shaping their everyday lives, according to a new study.
As political engagement increasingly takes place online, basic freedoms that many take for granted including free expression, freedom of information and freedom of assembly are undermined if some citizens have access to the internet and others do not.
New research reveals that the internet could be a key way of protecting other basic human rights such as life, liberty, and freedom from torture -- a means of enabling billions of people to lead 'minimally decent lives'.
Dr. Merten Reglitz, Lecturer in Global Ethics at the University of Birmingham, has published his findings -- the first study of its kind -- in the Journal of Applied Philosophy.
"Internet access is no luxury, but instead a moral human right and everyone should have unmonitored and uncensored access to this global medium -- provided free of charge for those unable to afford it," commented Dr Reglitz.
"Without such access, many people lack a meaningful way to influence and hold accountable supranational rule-makers and institutions. These individuals simply don't have a say in the making of the rules they must obey and which shape their life chances."
He added that exercising free speech and obtaining information was now heavily dependent on having internet access. Much of today's political debate took place online and politically relevant information is shared on the internet -- meaning the relative value these freedoms held for people 'offline' had decreased.
Dr. Reglitz's research attributes to the internet unprecedented possibilities for protecting basic human rights to life, liberty and bodily integrity.
Whilst acknowledging that being online does not guarantee these rights, he cites examples of internet engagement that helped hold Government and institutions to account. These examples include:
Dr. Reglitz defines 'moral human rights' as based on universal interests essential for a 'minimally decent life'. They must also be of such fundamental importance that if a nation is unwilling or unable to uphold these rights, the international community must step in.
The study points to a number of important political institutions which have committed to ensuring universal access for their populations, convinced that this goal is affordable:
Dr Reglitz outlines the size of the challenge posed in providing universal internet access, noting that the UN's International Telecommunication Union estimated that, by the end of 2018, 51 percent of the world's population of 7 billion people had access to the Internet.
Many people in poorer parts of the world are still without internet access, but their number is decreasing as technology becomes cheaper. However, internet expansion has slowed in recent years, suggesting universal access will not occur without intentional promotion.
"Universal internet access need not cost the earth -- accessing politically important opportunities such as blogging, obtaining information, joining virtual groups, or sending and receiving emails does not require the latest information technology," commented Dr Reglitz.
"Web-capable phones allow people to access these services and public internet provision, such as public libraries, can help get people online where individual domestic access is initially too expensive."
He added that the human right to internet access was similar to the global right to health, which cannot require globally the highest possible medical treatment, as many states are too poor to provide such services and thus would face impossible demands.
Instead, poor states are called upon to provide basic medical services and work toward providing higher quality health care delivery. Similarly, such states should initially offer locations with public Internet access and develop IT infrastructure that increases access.
Read more at Science Daily
As political engagement increasingly takes place online, basic freedoms that many take for granted including free expression, freedom of information and freedom of assembly are undermined if some citizens have access to the internet and others do not.
New research reveals that the internet could be a key way of protecting other basic human rights such as life, liberty, and freedom from torture -- a means of enabling billions of people to lead 'minimally decent lives'.
Dr. Merten Reglitz, Lecturer in Global Ethics at the University of Birmingham, has published his findings -- the first study of its kind -- in the Journal of Applied Philosophy.
"Internet access is no luxury, but instead a moral human right and everyone should have unmonitored and uncensored access to this global medium -- provided free of charge for those unable to afford it," commented Dr Reglitz.
"Without such access, many people lack a meaningful way to influence and hold accountable supranational rule-makers and institutions. These individuals simply don't have a say in the making of the rules they must obey and which shape their life chances."
He added that exercising free speech and obtaining information was now heavily dependent on having internet access. Much of today's political debate took place online and politically relevant information is shared on the internet -- meaning the relative value these freedoms held for people 'offline' had decreased.
Dr. Reglitz's research attributes to the internet unprecedented possibilities for protecting basic human rights to life, liberty and bodily integrity.
Whilst acknowledging that being online does not guarantee these rights, he cites examples of internet engagement that helped hold Government and institutions to account. These examples include:
- The 'Arab Spring'- new ways of global reporting on government atrocities.
- Documenting unjustified police violence against African Americans in the US.
- #MeToo campaign -- helping to 'out' sexual harassment of women by powerful men.
Dr. Reglitz defines 'moral human rights' as based on universal interests essential for a 'minimally decent life'. They must also be of such fundamental importance that if a nation is unwilling or unable to uphold these rights, the international community must step in.
The study points to a number of important political institutions which have committed to ensuring universal access for their populations, convinced that this goal is affordable:
- The Indian state of Kerala has declared universal internet access a human right and aims to provide it for its 35 million people by 2019.
- The European Union has launched the WiFi4EU initiative to provide 'every European village and city with free wireless internet access around main centres of public life by 2020.
- Global internet access is part of the UN Sustainable Development Goals, with the UN demanding states help to deliver universal Internet access in developing nations.
Dr Reglitz outlines the size of the challenge posed in providing universal internet access, noting that the UN's International Telecommunication Union estimated that, by the end of 2018, 51 percent of the world's population of 7 billion people had access to the Internet.
Many people in poorer parts of the world are still without internet access, but their number is decreasing as technology becomes cheaper. However, internet expansion has slowed in recent years, suggesting universal access will not occur without intentional promotion.
"Universal internet access need not cost the earth -- accessing politically important opportunities such as blogging, obtaining information, joining virtual groups, or sending and receiving emails does not require the latest information technology," commented Dr Reglitz.
"Web-capable phones allow people to access these services and public internet provision, such as public libraries, can help get people online where individual domestic access is initially too expensive."
He added that the human right to internet access was similar to the global right to health, which cannot require globally the highest possible medical treatment, as many states are too poor to provide such services and thus would face impossible demands.
Instead, poor states are called upon to provide basic medical services and work toward providing higher quality health care delivery. Similarly, such states should initially offer locations with public Internet access and develop IT infrastructure that increases access.
Read more at Science Daily
Humans' ability to read dogs' facial expressions is learned, not innate
Dogs were the first domesticated animal, with humans and dogs sharing more than 40,000 years of social interactions and life together. According to the co-domestication hypothesis, this process allowed humans and dogs to evolve special emotional signals and cognitive skills that favor mutual understanding. We know, for example, that over the millennia, dogs have evolved the ability to understand human words, iconic signs, and other gestures, and research has shown that dogs can even use tone of voice and facial expressions to recognize human emotions. Beyond personal testimony from dog lovers, however, little attention has been paid to how well humans can understand their canine counterparts.
In the current study, led by Federica Amici of the Max Planck Institute for Evolutionary Anthropology and Juliane Bräuer of the Max Planck Institute for the Science of Human History, the researchers set out to understand how well humans can understand the emotional displays of dogs, and where that understanding comes from.
How well do we understand our species' best friend?
In order to test how well humans can understand the emotions behind dog facial expressions, researchers collected photographs of dogs, chimpanzees, and humans displaying either happy, sad, angry, neutral, or fearful emotions as substantiated by the photographers. They then recruited 89 adult participants and 77 child participants and categorized them according to their age, the dog-positivity of their cultural context, and the participants' personal history of dog ownership.
Each participant was presented with photographs of dogs, chimps, and humans, and asked to rate how much the individual in the picture displayed happiness, sadness, anger, or fear. Adults were also asked to determine the context in which the picture had been taken (e.g., playing with a trusted conspecific partner; directly before attacking a conspecific). The results of the study showed that, while some dog emotions can be recognized from early on, the ability to reliably recognize dog emotions is mainly acquired through age and experience. In adults, the probability of recognizing dog emotions was higher for participants who grew up in a cultural context with a positive attitude towards dogs, regardless of whether they owned a dog themselves.
Without a dog-positive context, we could be barking up the wrong tree
A dog-postive cultural background, one in which dogs are closely integrated into human life and considered highly important, may result in a higher level of passive exposure and increased inclination and interest in dogs, making humans better at recognizing dogs' emotions even without a history of personal dog ownership. "These results are noteworthy," says Amici, "because they suggest that it is not necessarily direct experience with dogs that affects humans' ability to recognize their emotions, but rather the cultural milieu in which humans develop."
The researchers also found that regardless of age or experience with dogs, all participants were able to identify anger and happiness reliably. While these results may suggest an innate ability favored by the co-domestication hypothesis, it is also possible that humans learn to recognize these emotions quickly, even with limited exposure. Other than anger and happiness, the children in the study were not good at identifying dog emotions. They recognized anger and happiness more reliably in dogs than in chimps, but otherwise identified dog emotions as poorly as they did chimpanzee emotions, suggesting that the ability to understand how dogs are feeling is not innate.
Read more at Science Daily
In the current study, led by Federica Amici of the Max Planck Institute for Evolutionary Anthropology and Juliane Bräuer of the Max Planck Institute for the Science of Human History, the researchers set out to understand how well humans can understand the emotional displays of dogs, and where that understanding comes from.
How well do we understand our species' best friend?
In order to test how well humans can understand the emotions behind dog facial expressions, researchers collected photographs of dogs, chimpanzees, and humans displaying either happy, sad, angry, neutral, or fearful emotions as substantiated by the photographers. They then recruited 89 adult participants and 77 child participants and categorized them according to their age, the dog-positivity of their cultural context, and the participants' personal history of dog ownership.
Each participant was presented with photographs of dogs, chimps, and humans, and asked to rate how much the individual in the picture displayed happiness, sadness, anger, or fear. Adults were also asked to determine the context in which the picture had been taken (e.g., playing with a trusted conspecific partner; directly before attacking a conspecific). The results of the study showed that, while some dog emotions can be recognized from early on, the ability to reliably recognize dog emotions is mainly acquired through age and experience. In adults, the probability of recognizing dog emotions was higher for participants who grew up in a cultural context with a positive attitude towards dogs, regardless of whether they owned a dog themselves.
Without a dog-positive context, we could be barking up the wrong tree
A dog-postive cultural background, one in which dogs are closely integrated into human life and considered highly important, may result in a higher level of passive exposure and increased inclination and interest in dogs, making humans better at recognizing dogs' emotions even without a history of personal dog ownership. "These results are noteworthy," says Amici, "because they suggest that it is not necessarily direct experience with dogs that affects humans' ability to recognize their emotions, but rather the cultural milieu in which humans develop."
The researchers also found that regardless of age or experience with dogs, all participants were able to identify anger and happiness reliably. While these results may suggest an innate ability favored by the co-domestication hypothesis, it is also possible that humans learn to recognize these emotions quickly, even with limited exposure. Other than anger and happiness, the children in the study were not good at identifying dog emotions. They recognized anger and happiness more reliably in dogs than in chimps, but otherwise identified dog emotions as poorly as they did chimpanzee emotions, suggesting that the ability to understand how dogs are feeling is not innate.
Read more at Science Daily
Antibiotics: New substances break bacterial resistance
Researchers at the Martin Luther University Halle-Wittenberg (MLU) have developed a new, promising class of active ingredients against resistant bacteria. In initial tests in cell cultures and insects, the substances were at least as effective as common antibiotics. The new compounds target a special enzyme that only appears in bacteria in this specific form and that was not previously the target of other antibiotics. This is why bacteria have not yet developed any resistance to it. The team reported on its work in the journal Antibiotics.
Whether staphylococcus or the dreaded MRSA germs: resistant bacteria are a problem for physicians and patients worldwide. Only a few weeks ago, several large pharmaceutical companies also announced that they were further cutting back their own research work on new antibiotics. "However, in order to be able to treat infectious diseases reliably and in the long run, we need new active substances against which bacteria have not yet developed resistances," says Professor Andreas Hilgeroth from the Institute of Pharmacy at MLU. Together with researchers from the University of Greifswald and the Julius Maximilian University of Würzburg, he is working on these new active substances in a research project funded by the Federal Ministry of Education and Research.
The scientists have developed new active ingredients that attack a special enzyme that only appears in this form in pathogenic bacteria: the so-called pyruvate kinase. It plays an important role in metabolic processes. The idea: If the metabolism of the bacteria is obstructed, this ultimately renders them harmless. "The pyruvate kinase is an ideal target for new active ingredients. In the best case, the new substances only affect the bacterial enzyme and therefore the bacteria. If so, there should be only a few side effects. In addition, this new target structure can be used to break existing antibiotic resistance," Hilgeroth continues.
In cell experiments and initial tests on the larvae of the greater wax moth, a model organism used in life sciences, the researchers were able to confirm the efficacy of their new substances. The best compounds achieved at least as good results as conventional antibiotics. A patent application has also been filed for these active ingredients. "These initial results give us confidence that we are on the right track," Hilgeroth says. However, the ingredients still have to undergo numerous other tests before they can be tested in large-scale clinical trials on humans. Thus it may take more than ten years before the substances of the scientists from Halle, Würzburg and Greifswald become a marketable drug.
From Science Daily
Whether staphylococcus or the dreaded MRSA germs: resistant bacteria are a problem for physicians and patients worldwide. Only a few weeks ago, several large pharmaceutical companies also announced that they were further cutting back their own research work on new antibiotics. "However, in order to be able to treat infectious diseases reliably and in the long run, we need new active substances against which bacteria have not yet developed resistances," says Professor Andreas Hilgeroth from the Institute of Pharmacy at MLU. Together with researchers from the University of Greifswald and the Julius Maximilian University of Würzburg, he is working on these new active substances in a research project funded by the Federal Ministry of Education and Research.
The scientists have developed new active ingredients that attack a special enzyme that only appears in this form in pathogenic bacteria: the so-called pyruvate kinase. It plays an important role in metabolic processes. The idea: If the metabolism of the bacteria is obstructed, this ultimately renders them harmless. "The pyruvate kinase is an ideal target for new active ingredients. In the best case, the new substances only affect the bacterial enzyme and therefore the bacteria. If so, there should be only a few side effects. In addition, this new target structure can be used to break existing antibiotic resistance," Hilgeroth continues.
In cell experiments and initial tests on the larvae of the greater wax moth, a model organism used in life sciences, the researchers were able to confirm the efficacy of their new substances. The best compounds achieved at least as good results as conventional antibiotics. A patent application has also been filed for these active ingredients. "These initial results give us confidence that we are on the right track," Hilgeroth says. However, the ingredients still have to undergo numerous other tests before they can be tested in large-scale clinical trials on humans. Thus it may take more than ten years before the substances of the scientists from Halle, Würzburg and Greifswald become a marketable drug.
From Science Daily
Nov 10, 2019
How Human Population came from our ability to cooperate
Humans may owe their place as Earth's dominating species to their ability to share and cooperate with each other, according to a new study published in the Journal of Anthropological Research.
In "How There Got to Be So Many of Us: The Evolutionary Story of Population Growth and a Life History of Cooperation," Karen L. Kramer explores the deep past to discover the biological and social underpinnings that allowed humans to excel as reproducers and survivors. She argues that the human tendency to bear many children, engage in food sharing, division of labor, and cooperative childcare duties, sets us apart from our closest evolutionary counterparts, the apes.
In terms of population numbers, few species can compare to the success of humans. Though much attention on population size focuses on the past 200 years, humans were incredibly successful even before the industrial revolution, populating all of the world's environments with more than a billion people. Kramer uses her research on Maya agriculturalists of Mexico's Yucatan Peninsula and the Savanna Pumé hunter-gatherers of Venezuela to illustrate how cooperative childrearing increases the number of children that mothers can successfully raise and -- in environments where beneficial -- even speed up maturation and childbearing. Kramer argues that intergenerational cooperation, meaning that adults help support children, but children also share food and many other resources with their parents and other siblings, is at the center of humans' demographic success. "Together our diet and life history, coupled with an ability to cooperate, made us really good at getting food on the table, reproducing, and surviving," Kramer writes.
During her time with the Maya, Kramer constructed a demographic model that considered how much household members consume, as the family grows and matures across a mother's reproductive career, balanced against how much a mother, father, and their children contribute. She found that Maya children contributed a substantial amount of work to the family's survival, with those aged 7-14 spending on average 2 to 5 hours working each day, and children aged 15-18 spending as much as their parents, about 6.5 hours a day. Labor type varied, with younger children doing much of the childcare, older children and fathers fill in much of the day-today cost of growing and processing food and running the household. "If mothers and juveniles did not cooperate, mothers could support far fewer children over their reproductive careers," Kramer writes. "It is the strength of intergenerational cooperation that allows parents to raise more children than they would otherwise be able to on their efforts alone."
Kramer's second research population were the Savanna Pumé, hunter-gatherers in west-central Venezuela. The Savanna Pumé live in a high-mortality environment, with challenges such as seasonal undernutrition, high immunological stress, chronic intestinal parasite loads, endemic malaria, and no access to healthcare or immunization. Despite all this -- or perhaps, in part, because of it -- Savanna Pumé girls mature quickly and begin childbearing in their mid-teens. This pattern conforms with theoretic predictions that fast maturation optimizes fitness in a high-mortality environment. Early childbearing is also, however, associated with a higher probability of mothers losing their firstborn.
Kramer found that intergenerational cooperation mitigated these risks. "In this challenging environment, young Pumé females are buffered against seasonal fluctuations because food is shared with them, she writes. "If young Pumé mothers relied solely on their own efforts, they would have to delay childbearing until they matured as foragers and caretakers.
Humans' ability to reproduce more successfully than other great apes can be traced to differences in evolutionary strategy: humans bear more children, at a faster rate. They also provision food for juveniles, whereas other great apes stop helping children find food as soon as they have been weaned. Humans are able to shoulder the greater childcare burden through cooperation.
Read more at Science Daily
In "How There Got to Be So Many of Us: The Evolutionary Story of Population Growth and a Life History of Cooperation," Karen L. Kramer explores the deep past to discover the biological and social underpinnings that allowed humans to excel as reproducers and survivors. She argues that the human tendency to bear many children, engage in food sharing, division of labor, and cooperative childcare duties, sets us apart from our closest evolutionary counterparts, the apes.
In terms of population numbers, few species can compare to the success of humans. Though much attention on population size focuses on the past 200 years, humans were incredibly successful even before the industrial revolution, populating all of the world's environments with more than a billion people. Kramer uses her research on Maya agriculturalists of Mexico's Yucatan Peninsula and the Savanna Pumé hunter-gatherers of Venezuela to illustrate how cooperative childrearing increases the number of children that mothers can successfully raise and -- in environments where beneficial -- even speed up maturation and childbearing. Kramer argues that intergenerational cooperation, meaning that adults help support children, but children also share food and many other resources with their parents and other siblings, is at the center of humans' demographic success. "Together our diet and life history, coupled with an ability to cooperate, made us really good at getting food on the table, reproducing, and surviving," Kramer writes.
During her time with the Maya, Kramer constructed a demographic model that considered how much household members consume, as the family grows and matures across a mother's reproductive career, balanced against how much a mother, father, and their children contribute. She found that Maya children contributed a substantial amount of work to the family's survival, with those aged 7-14 spending on average 2 to 5 hours working each day, and children aged 15-18 spending as much as their parents, about 6.5 hours a day. Labor type varied, with younger children doing much of the childcare, older children and fathers fill in much of the day-today cost of growing and processing food and running the household. "If mothers and juveniles did not cooperate, mothers could support far fewer children over their reproductive careers," Kramer writes. "It is the strength of intergenerational cooperation that allows parents to raise more children than they would otherwise be able to on their efforts alone."
Kramer's second research population were the Savanna Pumé, hunter-gatherers in west-central Venezuela. The Savanna Pumé live in a high-mortality environment, with challenges such as seasonal undernutrition, high immunological stress, chronic intestinal parasite loads, endemic malaria, and no access to healthcare or immunization. Despite all this -- or perhaps, in part, because of it -- Savanna Pumé girls mature quickly and begin childbearing in their mid-teens. This pattern conforms with theoretic predictions that fast maturation optimizes fitness in a high-mortality environment. Early childbearing is also, however, associated with a higher probability of mothers losing their firstborn.
Kramer found that intergenerational cooperation mitigated these risks. "In this challenging environment, young Pumé females are buffered against seasonal fluctuations because food is shared with them, she writes. "If young Pumé mothers relied solely on their own efforts, they would have to delay childbearing until they matured as foragers and caretakers.
Humans' ability to reproduce more successfully than other great apes can be traced to differences in evolutionary strategy: humans bear more children, at a faster rate. They also provision food for juveniles, whereas other great apes stop helping children find food as soon as they have been weaned. Humans are able to shoulder the greater childcare burden through cooperation.
Read more at Science Daily
Brains of girls and boys are similar, producing equal math ability
In 1992, Teen Talk Barbie was released with the controversial voice fragment, "Math class is hard." While the toy's release met with public backlash, this underlying assumption persists, propagating the myth that women do not thrive in science, technology, engineering and mathematic (STEM) fields due to biological deficiencies in math aptitude.
Jessica Cantlon at Carnegie Mellon University led a research team that comprehensively examined the brain development of young boys and girls. Their research shows no gender difference in brain function or math ability. The results of this research are available online in the November 8 issue of the journal Science of Learning.
"Science doesn't align with folk beliefs," said Cantlon, the Ronald J. and Mary Ann Zdrojkowski Professor of Developmental Neuroscience at CMU's Dietrich College of Humanities and Social Sciences and senior author on the paper. "We see that children's brains function similarly regardless of their gender so hopefully we can recalibrate expectations of what children can achieve in mathematics."
Cantlon and her team conducted the first neuroimaging study to evaluate biological gender differences in math aptitude of young children.
Her team used functional MRI to measure the brain activity in 104 young children (3- to 10-years-old; 55 girls) while watching an educational video covering early math topics, like counting and addition. The researchers compared scans from the boys and girls to evaluate brain similarity. In addition, the team examined brain maturity by comparing the children's scans to those taken from a group of adults (63 adults; 25 women) who watched the same math videos.
After numerous statistical comparisons, Cantlon and her team found no difference in the brain development of girls and boys. In addition, the researchers found no difference in how boys and girls processed math skills and were equally engaged while watching the educational videos. Finally, boys' and girls' brain maturity were statistically equivalent when compared to either men or women in the adult group.
"It's not just that boys and girls are using the math network in the same ways but that similarities were evident across the entire brain," said Alyssa Kersey, postdoctoral scholar at the Department of Psychology, University of Chicago and first author on the paper. "This is an important reminder that humans are more similar to each other than we are different."
The researchers also compared the results of the Test of Early Mathematics Ability, a standardized test for 3- to 8-year-old children, from 97 participants (50 girls) to gauge the rate of math development. They found that math ability was equivalent among the children and did not show a difference in gender or with age. Nor did the team find a gender difference between math ability and brain maturity.
This study builds on the team's previous work that found equivalent behavioral performance on a range of mathematics tests between young boys and girls.
Cantlon said she thinks society and culture likely are steering girls and young women away from math and STEM fields. Previous studies show that families spend more time with young boys in play that involves spatial cognition. Many teachers also preferentially spend more time with boys during math class, predicting later math achievement. Finally, children often pick up on cues from their parent's expectations for math abilities.
"Typical socialization can exacerbate small differences between boys and girls that can snowball into how we treat them in science and math," Cantlon said. "We need to be cognizant of these origins to ensure we aren't the ones causing the gender inequities."
This project is focused on early childhood development using a limited set of math tasks. Cantlon wants to continue this work using a broader array of math skills, such as spatial processing and memory, and follow the children over many years.
Read more at Science Daily
Jessica Cantlon at Carnegie Mellon University led a research team that comprehensively examined the brain development of young boys and girls. Their research shows no gender difference in brain function or math ability. The results of this research are available online in the November 8 issue of the journal Science of Learning.
"Science doesn't align with folk beliefs," said Cantlon, the Ronald J. and Mary Ann Zdrojkowski Professor of Developmental Neuroscience at CMU's Dietrich College of Humanities and Social Sciences and senior author on the paper. "We see that children's brains function similarly regardless of their gender so hopefully we can recalibrate expectations of what children can achieve in mathematics."
Cantlon and her team conducted the first neuroimaging study to evaluate biological gender differences in math aptitude of young children.
Her team used functional MRI to measure the brain activity in 104 young children (3- to 10-years-old; 55 girls) while watching an educational video covering early math topics, like counting and addition. The researchers compared scans from the boys and girls to evaluate brain similarity. In addition, the team examined brain maturity by comparing the children's scans to those taken from a group of adults (63 adults; 25 women) who watched the same math videos.
After numerous statistical comparisons, Cantlon and her team found no difference in the brain development of girls and boys. In addition, the researchers found no difference in how boys and girls processed math skills and were equally engaged while watching the educational videos. Finally, boys' and girls' brain maturity were statistically equivalent when compared to either men or women in the adult group.
"It's not just that boys and girls are using the math network in the same ways but that similarities were evident across the entire brain," said Alyssa Kersey, postdoctoral scholar at the Department of Psychology, University of Chicago and first author on the paper. "This is an important reminder that humans are more similar to each other than we are different."
The researchers also compared the results of the Test of Early Mathematics Ability, a standardized test for 3- to 8-year-old children, from 97 participants (50 girls) to gauge the rate of math development. They found that math ability was equivalent among the children and did not show a difference in gender or with age. Nor did the team find a gender difference between math ability and brain maturity.
This study builds on the team's previous work that found equivalent behavioral performance on a range of mathematics tests between young boys and girls.
Cantlon said she thinks society and culture likely are steering girls and young women away from math and STEM fields. Previous studies show that families spend more time with young boys in play that involves spatial cognition. Many teachers also preferentially spend more time with boys during math class, predicting later math achievement. Finally, children often pick up on cues from their parent's expectations for math abilities.
"Typical socialization can exacerbate small differences between boys and girls that can snowball into how we treat them in science and math," Cantlon said. "We need to be cognizant of these origins to ensure we aren't the ones causing the gender inequities."
This project is focused on early childhood development using a limited set of math tasks. Cantlon wants to continue this work using a broader array of math skills, such as spatial processing and memory, and follow the children over many years.
Read more at Science Daily
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