Many researchers realize that mice and rats are social and chatty. They spend all day talking to each other, but what are they really saying? Not only are many rodent vocalizations unable to be heard by humans, but also existing computer programs to detect these vocalizations are flawed. They pick up other noises, are slow to analyze data, and rely on inflexible. rules-based algorithms to detect calls.
Two young scientists at the University of Washington School of Medicine developed a software program called DeepSqueak, which lifts this technological barrier and promotes broad adoption of rodent vocalization research.
This program takes an audio signal and transforms it into an image, or sonogram. By reframing an audio problem as a visual one, the researchers could take advantage of state-of-the-art machine vision algorithms developed for self-driving cars. DeepSqueak represents the first use of deep artificial neural networks in squeak detection.
The program is highlighted in a recent paper published in Neuropsychopharmacology and was presented at Neurosciences 2018.
"DeepSqueak uses biomimetic algorithms that learn to isolate vocalizations by being given labeled examples of vocalizations and noise," said co-author Russell Marx. Marx is a technician in the Neumaier lab, which investigates complex behaviors relating to stress and addiction, and created the program with Kevin Coffey, whose specialty is studying the psychological aspects of drugs.
So what have the researchers found out so far?
"The animals have a rich repertoire of calls, around 20 kinds," said Coffey, a postdoctoral fellow in the Neumaier lab.
"With drugs of abuse, you see both positive and negative calls," Coffey said, explaining the complicated nature of addiction.
Coffey said the rodents seem the happiest when they are anticipating reward, such as sugar, or are playing with their peers. Interestingly, when two male mice are together, he said, they make the same calls over and over.
However, when they sense a female mouse nearby, their vocalizations are more complex, as if they are singing a courtship song. This effect is even more dramatic when the male mouse can smell but not see the female mouse. This observation suggests that male mice have distinct songs for different stages of courtship.
John Neumaier, professor of psychiatry and behavioral sciences at the UW School of Medicine, head of the Division of Psychiatric Neurosciences and associate director of the Alcohol and Drug Abuse Institute, says his goal is to develop treatments for withdrawal from alcohol or opioids. He said DeepSqueak is going to help his lab get there much faster and credits his two young researchers for doing something no one has been able to do yet -- making ultrasonic vocalizations convenient, affordable and widely available."
Read more at Science Daily
Jan 7, 2019
Hubble takes gigantic image of the Triangulum Galaxy
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| This gigantic image of the Triangulum Galaxy -- also known as Messier 33 -- is a composite of about 54 different pointings with Hubble's Advanced Camera for Surveys. With a staggering size of 34 372 times 19 345 pixels, it is the second-largest image ever released by Hubble. It is only dwarfed by the image of the Andromeda Galaxy, released in 2016. |
This new image of the Triangulum Galaxy -- also known as Messier 33 or NGC 598 -- has a staggering 665 million pixels and showcases the central region of the galaxy and its inner spiral arms. To stitch together this gigantic mosaic, Hubble's Advanced Camera for Surveys needed to create 54 separate images.
Under excellent dark-sky conditions, the Triangulum Galaxy can be seen with the naked eye as a faint, blurry object in the constellation of Triangulum (the Triangle), where its ethereal glow is an exciting target for amateur astronomers.
At only three million light-years from Earth, the Triangulum Galaxy is a notable member of the Local Group -- it is the group's third-largest galaxy, but also the smallest spiral galaxy in the group. It measures only about 60,000 light-years across, compared to the 200,000 light-years of the Andromeda Galaxy; the Milky Way lies between these extremes at about 100,000 light-years in diameter.
The Triangulum Galaxy is not only surpassed in size by the other two spirals, but by the multitude of stars they contain. The Triangulum Galaxy has at least an order of magnitude less stars than the Milky Way and two orders of magnitude less than Andromeda. These numbers are hard to grasp when already in this image 10 to 15 million individual stars are visible.
In contrast to the two larger spirals, the Triangulum Galaxy doesn't have a bright bulge at its centre and it also lacks a bar connecting its spiral arms to the centre. It does, however, contain a huge amount of gas and dust, giving rise to rapid star formation. New stars form at a rate of approximately one solar mass every two years.
The abundance of gas clouds in the Triangulum Galaxy is precisely what drew astronomers to conduct this detailed survey. When stars are born, they use up material in these clouds of gas and dust, leaving less fuel for new stars to emerge. Hubble's image shows two of the four brightest of these regions in the galaxy: NGC 595 and NGC 604. The latter is the second most luminous region of ionised hydrogen within the Local Group and it is also among the largest known star formation regions in the Local Group.
Read more at Science Daily
Human brain allocates attention based on known size of objects
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| A stop sign in the foreground appears to be larger than cars parked across the street. |
Researchers at the George Washington University gained important insights into how the human brain processes information and allocates attention. Their study, "Attention Scales According to Inferred Real-World Object Size," shows people pay attention to objects based on their real-world size, rather than how they are perceived by the eye.
"Since a person can only pay attention to a limited amount of information at a time, our brain uses object size to determine how much attention to allocate to that object," Sarah Shomstein, a professor of cognitive neuroscience at the GW Columbian College of Arts and Sciences, said. "However, the way our eyes perceive an object can be different from its actual size, such as a car appearing large when it is close and small when it is far. Our study has shown for the first time that the brain adjusts attention based on our knowledge of an object's size, not how our eyes view it."
The findings could have significant impacts on many everyday tasks, from a radiologist looking for tumors of various sizes, to an airport security agent tasked with searching for threats hidden in luggage. This study suggests attention allocation can be trained, which could lead to improvements and efficiency in performing such tasks.
To determine whether the human brain differentially allocates attention depending on an object's size, Dr. Shomstein and her team showed participants several images of small and large everyday objects such as a domino or billiards table, but presented them at an identical fixed size. The team measured how long it took participants to identify probe targets that were embedded within object images.
Researchers found that responses were quicker across known smaller real-world sized objects compared to larger ones, even though the space occupied by both objects on the eye was the same.
"If objects are of identical size on your eye, but you know that one of them is smaller -- such as a domino nearby versus a pool table far away -- you allocate more attention to the smaller item," Dr. Shomstein said. "Your knowledge of the object's size overrides its physical size thereby adjusting how much attention your brain allocates to the objects."
The researchers also showed participants images of everyday objects on a screen and asked them to rate the size of each object on a scale of one to six, one being very small and six being very large. Findings showed a direct correlation between how participants rated the size of each object and how long it took them to respond to target stimuli within the image.
"Your own personal ratings determine how efficient you are going to be at attending to that object," co-author Andrew J. Collegio, a GW alumnus and researcher in Dr. Shomstein's Attention and Cognition Lab, said. "If you think the pool table is really large, then your attention is going to be less focused."
Dr. Shomstein and Dr. Collegio hope these findings will help future researchers predict how effectively people process particular objects as they pay attention to the world around them.
Read more at Science Daily
New materials could 'drive wound healing' by harnessing natural healing methods
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| Nurse bandages hands |
Now, Dr Ben Almquist and his team at Imperial College London have created a new molecule that could change the way traditional materials work with the body. Known as traction force-activated payloads (TrAPs), their method lets materials talk to the body's natural repair systems to drive healing.
The researchers say incorporating TrAPs into existing medical materials could revolutionise the way injuries are treated. Dr Almquist, from Imperial's Department of Bioengineering, said: "Our technology could help launch a new generation of materials that actively work with tissues to drive healing."
The findings are published today in Advanced Materials.
Cellular call to action
After an injury, cells 'crawl' through the collagen 'scaffolds' found in wounds, like spiders navigating webs. As they move, they pull on the scaffold, which activates hidden healing proteins that begin to repair injured tissue.
The researchers designed TrAPs as a way to recreate this natural healing method. They folded the DNA segments into three-dimensional shapes known as aptamers that cling tightly to proteins. Then, they attached a customisable 'handle' that cells can grab onto on one end, before attaching the opposite end to a scaffold such as collagen.
During laboratory testing of their technique, they found that cells pulled on the TrAPs as they crawled through the collagen scaffolds. The pulling made the TrAPs unravel like shoelaces to reveal and activate the healing proteins. These proteins instruct the healing cells to grow and multiply.
The researchers also found that by changing the cellular 'handle', they can change which type of cell can grab hold and pull, letting them tailor TrAPs to release specific therapeutic proteins based on which cells are present at a given point in time. In doing so, the TrAPs produce materials that can smartly interact with the correct type of cell at the correct time during wound repair.
This is the first time scientists have activated healing proteins using different types of cells in human-made materials. The technique mimics healing methods found in nature. Dr Almquist said: "Using cell movement to activate healing is found in creatures ranging from sea sponges to humans. Our approach mimics them and actively works with the different varieties of cells that arrive in our damaged tissue over time to promote healing."
From lab to humans
This approach is adaptable to different cell types, so could be used in a variety of injuries such as fractured bones, scar tissue after heart attacks, and damaged nerves. New techniques are also desperately needed for patients whose wounds won't heal despite current interventions, like diabetic foot ulcers, which are the leading cause of non-traumatic lower leg amputations.
TrAPs are relatively straightforward to create and are fully human-made, meaning they are easily recreated in different labs and can be scaled up to industrial quantities. Their adaptability also means they could help scientists create new methods for laboratory studies of diseases, stem cells, and tissue development.
Aptamers are currently used as drugs, meaning they are already proven safe and optimised for clinical use. Because TrAPs take advantage of aptamers that are currently optimised for use in humans, they may be able to take a shorter path to the clinic than methods that start from ground zero.
Dr Almquist said: "The TrAP technology provides a flexible method to create materials that actively communicate with the wound and provide key instructions when and where they are needed. This sort of intelligent, dynamic healing is useful during every phase of the healing process, has the potential to increase the body's chance to recover, and has far-reaching uses on many different types of wounds. This technology has the potential to serve as a conductor of wound repair, orchestrating different cells over time to work together to heal damaged tissues."
Read more at Science Daily
Jan 6, 2019
Computers can be a real pain in the neck
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| Two San Francisco State University students show how people compress their neck at the computer. |
"When your posture is tall and erect, the muscles of your back can easily support the weight of your head and neck -- as much as 12 pounds," explains San Francisco State University Professor of Holistic Health Erik Peper. "But when your head juts forward at a 45 degree angle, your neck acts like a fulcrum, like a long lever lifting a heavy object. Now the muscle weight of your head and neck is the equivalent of about 45 pounds. It is not surprising people get stiff necks and shoulder and back pain."
Peper, Associate Professor of Health Education Richard Harvey and their colleagues, including two student researchers, tested the effects of head and neck position in a recent study published in the journal Biofeedback. First they asked 87 students to sit upright with their heads properly aligned on their necks and asked them to turn their heads. Then the students were asked to "scrunch" their necks and jut their heads forward. Ninety-two percent reported being able to turn their heads much farther when not scrunching. In the second test, 125 students scrunched their necks for 30 seconds. Afterwards, 98 percent reported some level of pain in their head, neck or eyes.
The researchers also monitored 12 students with electromyography equipment and found that trapezius muscle tension increased in the scrunched, head forward position.
So if you suffer from headaches or neck and backaches from computer work, check your posture and make sure your head is aligned on top of your neck, as if held by an invisible thread from the ceiling. "You can do something about this poor posture very quickly," said Peper. To increase body awareness, Peper advises purposefully replicating the head-forward/neck scrunched position. "You can exaggerate the position and experience the symptoms. Then when you find yourself doing it, you can become aware and stop."
Read more at Science Daily
Brains of people with schizophrenia-related disorders aren't all the same
A new multi-site brain imaging study in The American Journal of Psychiatry shows that sub-groups of people use their brains differently when imitating emotional faces -- a task that reflects their ability to interact socially. Interestingly, individuals with schizophrenia do not have categorically different social brain function than those without mental illness, but fall into different sub-groups that may respond to different types of treatments. These findings call into question the most common research approaches in mental health.
"We know that, on average, people with schizophrenia have more social impairment than people in the general population," says senior author Dr. Aristotle Voineskos in the Campbell Family Mental Health Research Institute at the Centre for Addiction and Mental Health (CAMH) in Toronto. "But we needed to take an agnostic approach and let the data tell us what the brain-behavioural profiles of our study participants looked like. It turned out that the relationship between brain function and social behaviour had nothing to do with conventional diagnostic categories in the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders)."
Most brain research in the mental health field compares a disease group to a non-disease or "healthy" group to search for biomarkers, a biological measure of mental health symptoms. This search for biomarkers has been elusive. This multi-site research study -- which included 179 participants recruited at CAMH in Toronto, Zucker Hillside Hospital in New York and the Maryland Psychiatric Research Center in Baltimore -- calls that paradigm into question because people with the same mental illness may not show the same biological patterns.
The study, which involved participants completing a facial imitation task while undergoing functional MRI brain scans, found three "activation profiles," says first author Dr. Colin Hawco, also of CAMH. These can be described as typical, over-activated and de-activated profiles.
"We think those with over-activated networks may be 'inefficient' in terms of brain activity -- they probably struggled more and needed to work harder to do the same task compared to the other groups," says Dr. Hawco. "The 'de-activating' group seemed to show very efficient use of their brain, and did better on behavioural tests of social processing as well." These findings were true for participants with and without schizophrenia.
"There is really no effective treatment to deal with these social impairments, which is why we're really invested in figuring out the brain networks of social behaviours as targets for treatment and research," says Dr. Anil Malhotra, Director of Research at the Zucker Hillside Hospital. "We are now positioned to test treatments to help change brain function, rather than focusing on symptoms alone, when it comes to helping people with social impairment."
People with social impairments may not be able to react as expected to emotions they see in others, such as fear, sadness or happiness. "As social impairments become more severe, people are more likely to be isolated, unable to function in daily life, and have a marked reduction in their quality of life," says Dr. Robert Buchanan, Director of the Maryland Psychiatric Research Center, a psychiatrist and researcher who has been working to find new treatments to improve social function over the past three decades.
The findings were bolstered by an independent replication sample of 108 participants, which showed the same brain function findings as in the original sample.
The study, known as the Social Processes Initiative in Neurobiology of the Schizophrenia(s) (SPINS) was funded by the National Institute of Mental Health as part of its Research Domain Criteria (RDoC) initiative.
Read more at Science Daily
"We know that, on average, people with schizophrenia have more social impairment than people in the general population," says senior author Dr. Aristotle Voineskos in the Campbell Family Mental Health Research Institute at the Centre for Addiction and Mental Health (CAMH) in Toronto. "But we needed to take an agnostic approach and let the data tell us what the brain-behavioural profiles of our study participants looked like. It turned out that the relationship between brain function and social behaviour had nothing to do with conventional diagnostic categories in the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders)."
Most brain research in the mental health field compares a disease group to a non-disease or "healthy" group to search for biomarkers, a biological measure of mental health symptoms. This search for biomarkers has been elusive. This multi-site research study -- which included 179 participants recruited at CAMH in Toronto, Zucker Hillside Hospital in New York and the Maryland Psychiatric Research Center in Baltimore -- calls that paradigm into question because people with the same mental illness may not show the same biological patterns.
The study, which involved participants completing a facial imitation task while undergoing functional MRI brain scans, found three "activation profiles," says first author Dr. Colin Hawco, also of CAMH. These can be described as typical, over-activated and de-activated profiles.
"We think those with over-activated networks may be 'inefficient' in terms of brain activity -- they probably struggled more and needed to work harder to do the same task compared to the other groups," says Dr. Hawco. "The 'de-activating' group seemed to show very efficient use of their brain, and did better on behavioural tests of social processing as well." These findings were true for participants with and without schizophrenia.
"There is really no effective treatment to deal with these social impairments, which is why we're really invested in figuring out the brain networks of social behaviours as targets for treatment and research," says Dr. Anil Malhotra, Director of Research at the Zucker Hillside Hospital. "We are now positioned to test treatments to help change brain function, rather than focusing on symptoms alone, when it comes to helping people with social impairment."
People with social impairments may not be able to react as expected to emotions they see in others, such as fear, sadness or happiness. "As social impairments become more severe, people are more likely to be isolated, unable to function in daily life, and have a marked reduction in their quality of life," says Dr. Robert Buchanan, Director of the Maryland Psychiatric Research Center, a psychiatrist and researcher who has been working to find new treatments to improve social function over the past three decades.
The findings were bolstered by an independent replication sample of 108 participants, which showed the same brain function findings as in the original sample.
The study, known as the Social Processes Initiative in Neurobiology of the Schizophrenia(s) (SPINS) was funded by the National Institute of Mental Health as part of its Research Domain Criteria (RDoC) initiative.
Read more at Science Daily
Jan 5, 2019
Stopping cancer from recruiting immune system double agents
Cancerous tumors trick myeloid cells, an important part of the immune system, into perceiving them as a damaged part of the body; the tumors actually put myeloid cells to work helping them grow and metastasize (spread). A research team co-led by scientists at Rush University Medical Center have discovered a potential therapy that can disrupt this recruitment and abnormal function of myeloid cells in laboratory mice. The findings of their latest study were published on Dec. 19 in Nature Communications.
Myeloid cells are a type of white blood cell that kills invaders like bacteria and cancer. "In the cancer context, myeloid cells promote tumor growth and suppress the activity of T cells," says Vineet Gupta, PhD, professor and vice chairperson for research and innovation in the Department of Internal Medicine at Rush Medical College.
Gupta and Judith Varner, PhD, of the Moores Cancer Center at the University of California at San Diego (UCSD) in California, were co-senior corresponding authors on the study. Samia Khan, PhD, a post-doctoral fellow in Gupta's lab; and Michael Schmid, PhD, and Megan Kaneda, PhD, with UCSD, were co-first authors.
Cancer recruit harmful myeloid cells, while suppressing helpful ones
Gupta's research focuses in general on integrins, a type of protein that are cellular receptors and regulate a number of biological processes. In this study, investigators looked at the integrin CD11b, which I present on myeloid cells and normally helps myeloid cell migration and its ability to fight disease.
Here, the researchers found that CD11b promotes development of myeloid cells into one sub-type, the M1 macrophage, that functions appropriately to suppress tumor growth. However, the tumors often suppress CD11b activity that results in development of the myeloid cells into a different type of cell, the M2 macrophage. These cells actually ward off T cells, which are vital to fighting disease, and M2s also secrete growth factors and promote the development of new blood vessels that allow cancer to grow and metastasize.
In previous research, agents developed to activate T cells have been "extremely effective in controlling tumor growth," Gupta says, but that approach, known as immunotherapy, has not resulted in a universal treatment for cancer. The hunt goes on.
Study found that CD11b is critical in regulating myeloid cells
In this study, the team explored how modifying the activity of CD11b affects myeloid cell behavior in the presence of cancer and if that could be used as a novel strategy to treat cancers. Using a small molecule discovered in the Gupta laboratory, Leukadherin-1 (LA-1), which in the body activates CD11b, the researchers developed a therapy that can boost the function of CD11b to promote the disease-fighting M1 type of myeloid cells, helping create a microenvironment at the tumor site where T cells can enter and attack the cancer.
The study used two types of genetically altered mice. One set of experiments was done with otherwise normal mice that lacked CD11b. Transplanted tumors grew much larger in those mice as compared to the tumors in wild-type (normal) mice, suggesting that CD11b restrains tumor growth.
Exploring further the reason for this difference, the team found that CD11b plays a critical role in regulating the polarization of myeloid cells into M1 or M2 macrophages. In the absence of CD11b, most of the myeloids cells in tumors were the M2 sub-type, that help the tumor grow and spread.
Boosting CD11b activity helped reduce tumor growth
In a different experiment, the team used LA-1 to boost CD11b activity beyond its normal levels in wild-type (normal) mice, and discovered that this increase caused a significant reduction in tumor growth in treated animals. Then, to be sure that their pharmacological intervention was directly due to the effects of LA-1 on CD11b, they created a mouse with a "point mutation" (a genetic mutation at a single residue in the CD11b protein sequence) and created a situation in which CD11b was active all the time (which is usually isn't) in the genetically modified animals.
"The boost in CD11b activity in the mouse with the point mutation mimics the one imparted on CD11b in normal mice with administration of LA-1," Gupta says. "The results were the same," Gupta says. In both cases, the tumors shrank dramatically, suggesting CD11b activation as an novel target for cancer immunotherapy.
In this study, LA-1 showed a great deal of promise, although, Gupta says it will be years before a treatment based on this molecule becomes available to patients. The results are very encouraging and will continue to motivate the team to move this novel approach towards developing treatments for patients.
Read more at Science Daily
Myeloid cells are a type of white blood cell that kills invaders like bacteria and cancer. "In the cancer context, myeloid cells promote tumor growth and suppress the activity of T cells," says Vineet Gupta, PhD, professor and vice chairperson for research and innovation in the Department of Internal Medicine at Rush Medical College.
Gupta and Judith Varner, PhD, of the Moores Cancer Center at the University of California at San Diego (UCSD) in California, were co-senior corresponding authors on the study. Samia Khan, PhD, a post-doctoral fellow in Gupta's lab; and Michael Schmid, PhD, and Megan Kaneda, PhD, with UCSD, were co-first authors.
Cancer recruit harmful myeloid cells, while suppressing helpful ones
Gupta's research focuses in general on integrins, a type of protein that are cellular receptors and regulate a number of biological processes. In this study, investigators looked at the integrin CD11b, which I present on myeloid cells and normally helps myeloid cell migration and its ability to fight disease.
Here, the researchers found that CD11b promotes development of myeloid cells into one sub-type, the M1 macrophage, that functions appropriately to suppress tumor growth. However, the tumors often suppress CD11b activity that results in development of the myeloid cells into a different type of cell, the M2 macrophage. These cells actually ward off T cells, which are vital to fighting disease, and M2s also secrete growth factors and promote the development of new blood vessels that allow cancer to grow and metastasize.
In previous research, agents developed to activate T cells have been "extremely effective in controlling tumor growth," Gupta says, but that approach, known as immunotherapy, has not resulted in a universal treatment for cancer. The hunt goes on.
Study found that CD11b is critical in regulating myeloid cells
In this study, the team explored how modifying the activity of CD11b affects myeloid cell behavior in the presence of cancer and if that could be used as a novel strategy to treat cancers. Using a small molecule discovered in the Gupta laboratory, Leukadherin-1 (LA-1), which in the body activates CD11b, the researchers developed a therapy that can boost the function of CD11b to promote the disease-fighting M1 type of myeloid cells, helping create a microenvironment at the tumor site where T cells can enter and attack the cancer.
The study used two types of genetically altered mice. One set of experiments was done with otherwise normal mice that lacked CD11b. Transplanted tumors grew much larger in those mice as compared to the tumors in wild-type (normal) mice, suggesting that CD11b restrains tumor growth.
Exploring further the reason for this difference, the team found that CD11b plays a critical role in regulating the polarization of myeloid cells into M1 or M2 macrophages. In the absence of CD11b, most of the myeloids cells in tumors were the M2 sub-type, that help the tumor grow and spread.
Boosting CD11b activity helped reduce tumor growth
In a different experiment, the team used LA-1 to boost CD11b activity beyond its normal levels in wild-type (normal) mice, and discovered that this increase caused a significant reduction in tumor growth in treated animals. Then, to be sure that their pharmacological intervention was directly due to the effects of LA-1 on CD11b, they created a mouse with a "point mutation" (a genetic mutation at a single residue in the CD11b protein sequence) and created a situation in which CD11b was active all the time (which is usually isn't) in the genetically modified animals.
"The boost in CD11b activity in the mouse with the point mutation mimics the one imparted on CD11b in normal mice with administration of LA-1," Gupta says. "The results were the same," Gupta says. In both cases, the tumors shrank dramatically, suggesting CD11b activation as an novel target for cancer immunotherapy.
In this study, LA-1 showed a great deal of promise, although, Gupta says it will be years before a treatment based on this molecule becomes available to patients. The results are very encouraging and will continue to motivate the team to move this novel approach towards developing treatments for patients.
Read more at Science Daily
One in 10 adults in US has food allergy, but nearly 1 in 5 think they do
Over 10 percent of adults in the U.S. -- over 26 million -- are estimated to have food allergy, according to a study published in JAMA Network Open that was led by Ruchi Gupta, MD, MPH, from Ann & Robert H. Lurie Children's Hospital of Chicago and Northwestern University. However, researchers found that 19 percent of adults think they are currently food allergic, although their reported symptoms are inconsistent with a true food allergy, which can trigger a life-threatening reaction. Results are based on a nationally representative survey of over 40,000 adults.
"While we found that one in 10 adults have food allergy, nearly twice as many adults think that they are allergic to foods, while their symptoms may suggest food intolerance or other food related conditions," says lead author Ruchi Gupta, MD, MPH, from Lurie Children's, who also is a Professor of Pediatrics at Northwestern University Feinberg School of Medicine. "It is important to see a physician for appropriate testing and diagnosis before completely eliminating foods from the diet. If food allergy is confirmed, understanding the management is also critical, including recognizing symptoms of anaphylaxis and how and when to use epinephrine."
Researchers discovered that only half of adults with convincing food allergy had a physician-confirmed diagnosis, and less than 25 percent reported a current epinephrine prescription.
Researchers also found that nearly half of food-allergic adults developed at least one of their food allergies as an adult.
"We were surprised to find that adult-onset food allergies were so common," says Dr. Gupta. "More research is needed to understand why this is occurring and how we might prevent it."
The study data indicate that the most prevalent food allergens among U.S. adults are shellfish (affecting 7.2 million adults), milk (4.7 million), peanut (4.5 million), tree nut (3 million), fin fish (2.2 million), egg (2 million), wheat (2 million), soy (1.5 million), and sesame (.5 million).
Read more at Science Daily
"While we found that one in 10 adults have food allergy, nearly twice as many adults think that they are allergic to foods, while their symptoms may suggest food intolerance or other food related conditions," says lead author Ruchi Gupta, MD, MPH, from Lurie Children's, who also is a Professor of Pediatrics at Northwestern University Feinberg School of Medicine. "It is important to see a physician for appropriate testing and diagnosis before completely eliminating foods from the diet. If food allergy is confirmed, understanding the management is also critical, including recognizing symptoms of anaphylaxis and how and when to use epinephrine."
Researchers discovered that only half of adults with convincing food allergy had a physician-confirmed diagnosis, and less than 25 percent reported a current epinephrine prescription.
Researchers also found that nearly half of food-allergic adults developed at least one of their food allergies as an adult.
"We were surprised to find that adult-onset food allergies were so common," says Dr. Gupta. "More research is needed to understand why this is occurring and how we might prevent it."
The study data indicate that the most prevalent food allergens among U.S. adults are shellfish (affecting 7.2 million adults), milk (4.7 million), peanut (4.5 million), tree nut (3 million), fin fish (2.2 million), egg (2 million), wheat (2 million), soy (1.5 million), and sesame (.5 million).
Read more at Science Daily
Jan 4, 2019
Dark matter on the move
Scientists have found evidence that dark matter can be heated up and moved around, as a result of star formation in galaxies. The findings provide the first observational evidence for the effect known as 'dark matter heating', and give new clues as to what makes up dark matter. The research is published today in the journal Monthly Notices of the Royal Astronomical Society.
In the new work, scientists from the University of Surrey, Carnegie Mellon University and ETH Zürich set out to hunt for evidence for dark matter at the centres of nearby dwarf galaxies. Dwarf galaxies are small, faint galaxies that are typically found orbiting larger galaxies like our own Milky Way. They may hold clues that could help us to better understand the nature of dark matter.
Dark matter is thought to make up most of the mass of the universe. However since it doesn't interact with light in the same way as normal matter, it can only be observed through its gravitational effects. The key to studying it may however lie in how stars are formed in these galaxies.
When stars form, strong winds can push gas and dust away from the heart of the galaxy. As a result, the galaxy's centre has less mass, which affects how much gravity is felt by the remaining dark matter. With less gravitational attraction, the dark matter gains energy and migrates away from the centre, an effect called 'dark matter heating'.
The team of astrophysicists measured the amount of dark matter at the centres of 16 dwarf galaxies with very different star formation histories. They found that galaxies that stopped forming stars long ago had higher dark matter densities at their centres than those that are still forming stars today. This supports the theory that the older galaxies had less dark matter heating.
Professor Justin Read, lead author of the study and Head of the Department of Physics at the University of Surrey, said: "We found a truly remarkable relationship between the amount of dark matter at the centres of these tiny dwarfs, and the amount of star formation they have experienced over their lives. The dark matter at the centres of the star-forming dwarfs appears to have been 'heated up' and pushed out."
The findings provide a new constraint on dark matter models: dark matter must be able to form dwarf galaxies that exhibit a range of central densities, and those densities must relate to the amount of star formation.
Professor Matthew Walker, a co-author from Carnegie Mellon University, added: "This study may be the "smoking gun" evidence that takes us a step closer to understanding what dark matter is. Our finding that it can be heated up and moved around helps to motivate searches for a dark matter particle."
Read more at Science Daily
In the new work, scientists from the University of Surrey, Carnegie Mellon University and ETH Zürich set out to hunt for evidence for dark matter at the centres of nearby dwarf galaxies. Dwarf galaxies are small, faint galaxies that are typically found orbiting larger galaxies like our own Milky Way. They may hold clues that could help us to better understand the nature of dark matter.
Dark matter is thought to make up most of the mass of the universe. However since it doesn't interact with light in the same way as normal matter, it can only be observed through its gravitational effects. The key to studying it may however lie in how stars are formed in these galaxies.
When stars form, strong winds can push gas and dust away from the heart of the galaxy. As a result, the galaxy's centre has less mass, which affects how much gravity is felt by the remaining dark matter. With less gravitational attraction, the dark matter gains energy and migrates away from the centre, an effect called 'dark matter heating'.
The team of astrophysicists measured the amount of dark matter at the centres of 16 dwarf galaxies with very different star formation histories. They found that galaxies that stopped forming stars long ago had higher dark matter densities at their centres than those that are still forming stars today. This supports the theory that the older galaxies had less dark matter heating.
Professor Justin Read, lead author of the study and Head of the Department of Physics at the University of Surrey, said: "We found a truly remarkable relationship between the amount of dark matter at the centres of these tiny dwarfs, and the amount of star formation they have experienced over their lives. The dark matter at the centres of the star-forming dwarfs appears to have been 'heated up' and pushed out."
The findings provide a new constraint on dark matter models: dark matter must be able to form dwarf galaxies that exhibit a range of central densities, and those densities must relate to the amount of star formation.
Professor Matthew Walker, a co-author from Carnegie Mellon University, added: "This study may be the "smoking gun" evidence that takes us a step closer to understanding what dark matter is. Our finding that it can be heated up and moved around helps to motivate searches for a dark matter particle."
Read more at Science Daily
The long memory of the Pacific Ocean
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| Cold waters that sank in polar regions hundreds of years ago during the Little Ice Age are still impacting deep Pacific Ocean temperature trends. While the deep Pacific temperature trends are small, they represent a large amount of energy in the Earth system. |
Researchers from the Woods Hole Oceanographic Institution (WHOI) and Harvard University have found that the deep Pacific Ocean lags a few centuries behind in terms of temperature and is still adjusting to the entry into the Little Ice Age. Whereas most of the ocean is responding to modern warming, the deep Pacific may be cooling.
"These waters are so old and haven't been near the surface in so long, they still 'remember' what was going on hundreds of years ago when Europe experienced some of its coldest winters in history," said Jake Gebbie, a physical oceanographer at WHOI and lead author of the study published Jan. 4, 2019, in the journal Science.
"Climate varies across all timescales," adds Peter Huybers, Professor of Earth and Planetary Sciences at Harvard University and co-author of the paper. "Some regional warming and cooling patterns, like the Little Ice Age and the Medieval Warm Period, are well known. Our goal was to develop a model of how the interior properties of the ocean respond to changes in surface climate."
What that model showed was surprising.
"If the surface ocean was generally cooling for the better part of the last millennium, those parts of the ocean most isolated from modern warming may still be cooling," said Gebbie.
The model is, of course, a simplification of the actual ocean. To test the prediction, Gebbie and Huybers compared the cooling trend found in the model to ocean temperature measurements taken by scientists aboard the HMS Challenger in the 1870s and modern observations from the World Ocean Circulation Experiment of the 1990s.
The HMS Challenger, a three-masted wooden sailing ship originally designed as a British warship, was used for the first modern scientific expedition to explore the world's ocean and seafloor. During the expedition from 1872 to 1876, thermometers were lowered into the ocean depths and more than 5,000 temperature measurements were logged.
"We screened this historical data for outliers and considered a variety of corrections associated with pressure effects on the thermometer and stretching of the hemp rope used for lowering thermometers," said Huybers.
The researchers then compared the HMS Challenger data to the modern observations and found warming in most parts of the global ocean, as would be expected due to the warming planet over the 20th Century, but cooling in the deep Pacific at a depth of around two kilometers.
"The close correspondence between the predictions and observed trends gave us confidence that this is a real phenomenon," said Gebbie.
These findings imply that variations in surface climate that predate the onset of modern warming still influence how much the climate is heating up today. Previous estimates of how much heat the Earth had absorbed during the last century assumed an ocean that started out in equilibrium at the beginning of the Industrial Revolution. But Gebbie and Huybers estimate that the deep Pacific cooling trend leads to a downward revision of heat absorbed over the 20th century by about 30 percent.
Read more at Science Daily
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