Gaining even a little weight over time may alter the structure and function of heart muscle, affecting long-term risk of heart failure, the Open Access Journal of the American Heart Association/American Stroke Association.
Researchers followed 1,262 adults (average age 44, 57 percent women, 44 percent black, 36 percent obese) who were free from heart disease and other conditions that put them at high risk for heart disease for seven years. Participants had MRIs scans of their hearts and multiple body fat measurements at the start of the study and then seven years later.
Researchers found those who gained weight:
- even as little as 5 percent, were more likely to have thickening and enlargement of the left ventricle, well-established indicators of future heart failure;
- were more likely to exhibit subtle decreases in their hearts’ pumping ability; and
- were more likely to exhibit changes in heart muscle appearance and function that persisted even after the researchers eliminated other factors that could affect heart muscle performance and appearance, including high blood pressure, diabetes, smoking and alcohol use.
Conversely, people who lost weight were more likely to exhibit decreases in heart muscle thickness.
Notably, how much a person weighed at the beginning of the study didn’t impact the changes, suggesting that even those of normal weight could experience adverse heart effects if they gain weight over time, researchers said.
“Any weight gain may lead to detrimental changes in the heart above and beyond the effects of baseline weight so that prevention should focus on weight loss or if meaningful weight loss cannot be achieved — the focus should be on weight stability,” said Ian Neeland, M.D., study senior author and a cardiologist and assistant professor of medicine at University of Texas Southwestern Medical Center in Dallas, Texas. “Counseling to maintain weight stability, even in the absence of weight loss, may be an important preventive strategy among high-risk individuals.”
The researchers caution that their study was relatively small and their findings do not mean that every person with weight gain will necessarily develop heart failure. The results do suggest that changes in weight may affect heart muscle in ways that can change the organ’s function.
Managing lifestyle factors such as hearing loss, smoking, hypertension and depression could prevent one-third of the world’s dementia cases, the report also highlights the beneficial effects of nonpharmacologic interventions such as social contact and exercise for people with dementia.
“There’s been a great deal of focus on developing medicines to prevent dementia, including Alzheimer’s disease,” says commission member and AAIC presenter Lon Schneider, MD, professor of psychiatry and the behavioral sciences at the Keck School of Medicine of USC. “But we can’t lose sight of the real major advances we’ve already made in treating dementia, including preventive approaches.”
The commission brought together 24 international experts to systematically review existing research and provide evidence-based recommendations for treating and preventing dementia. About 47 million people have dementia worldwide and that number is expected to climb as high as 66 million by 2030 and 115 million by 2050.
Reducing dementia risk, beginning in childhood
The commission’s report identifies nine risk factors in early, mid- and late life that increase the likelihood of developing dementia. About 35 percent of dementia — one in three cases — is attributable to these risk factors, the report says.
By increasing education in early life and addressing hearing loss, hypertension and obesity in midlife, the incidence of dementia could be reduced by as much as 20 percent, combined.
In late life, stopping smoking, treating depression, increasing physical activity, increasing social contact and managing diabetes could reduce the incidence of dementia by another 15 percent.
“The potential magnitude of the effect on dementia of reducing these risk factors is larger than we could ever imagine the effect that current, experimental medications could have,” Schneider says. “Mitigating risk factors provides us a powerful way to reduce the global burden of dementia.”
A nonpharmacologic approach to treating dementia
The commission also examined the effect of nonpharmacologic interventions for people with dementia and concluded that they had an important role in treatment, especially when trying to address agitation and aggression.
“Antipsychotic drugs are commonly used to treat agitation and aggression, but there is substantial concern about these drugs because of an increased risk of death, cardiovascular adverse events and infections, not to mention excessive sedation,” Schneider says.
The evidence showed that psychological, social and environmental interventions such as social contact and activities were superior to antipsychotic medications for treating dementia-related agitation and aggression.
The commission also found that nonpharmacologic interventions like group cognitive stimulation therapy and exercise conferred some benefit in cognition as well.
The commission’s full report provides detailed recommendations in the areas of prevention, treating cognitive symptoms, individualizing dementia care, caring for caregivers, planning for the future following a dementia diagnosis, managing neuropsychiatric symptoms and considering the end of life.
Solutions to climate change, and particularly its effects on the ocean, are needed now more than ever. Coral bleaching caused by climate change is a huge threat to coral reefs. Recent extreme bleaching events have already killed corals worldwide and permanent destruction of reefs is projected within the century if immediate action is not taken. However, genetically engineering a group of microalgae found in corals may enhance their stress tolerance to ocean warming and save coral reefs.
Coral reefs are our most diverse marine habitat. They provide over US$30 billion to the world economy every year and directly support over 500 million people. However, they are vulnerable with climate change impact models predicting that most of our coral reefs will be eradicated within this century if we do not act immediately to protect them.
Dr Rachel Levin from The University of New South Wales, Australia and her international team of researchers may have found a solution to reduce coral bleaching by genetically engineering the microalgae found in corals, enhancing their stress tolerance to ocean warming.
These microalgae are called Symbiodinium, a genus of primary producers found in coral that are essential for coral reef health and, thereby, critical to ocean productivity. Symbiodinium photosynthesize to produce molecules that feed the corals, which is necessary corals to grow and form coral reefs.
Coral bleaching is caused by changes in ocean temperatures which harm Symbiodinium, leading corals to lose their symbiotic Symbiodinium and therefore starve to death.
Different species of Symbiodinium have large genetic variation and diverse thermal tolerances which effect the bleaching tolerance of corals. In research published in Frontiers in Microbiology, the researchers use sequencing data from Symbiodinium to design genetic engineering strategies for enhancing stress tolerance of Symbiodinium, which may reduce coral bleaching due to rising ocean temperatures.
“Very little is known about Symbiodinium, thus very little information is available to improve coral reef conservation efforts. Symbiodinium is very biologically unusual, which has made it incompatible with well-established genetic engineering methods. We therefore aimed to overcome this roadblock by conducting novel genetic analyses of Symbiodinium to enable much needed research progress” explains Dr Rachel Levin, on the difficulties of studying these microalgae.
“Symbiodinium that have been genetically enhanced to maintain their symbiosis with corals under rising ocean temperatures has great potential to reduce coral bleaching globally” they suggest.
However, Dr Levin does warn that this is no easy miracle cure, “If lab experiments successfully show that genetically engineered Symbiodinium can prevent coral bleaching, these enhanced Symbiodinium would not be immediately released onto coral reefs. Extensive, rigorous studies evaluating any potentially negative impacts would be absolutely necessary before any field-based trials on this technology begin.”
In order to progress, other researchers will need to contribute to this research to advance the information currently available, “We have developed the first, tailored genetic engineering framework to be applied to Symbiodinium. Now this framework must be comprehensively tested and optimized. This is a tall order that will be greatly benefitted by collaborative efforts.”
The international Spitzer Adaptation of the Red-sequence Cluster Survey (SpARCS) collaboration based at the University of California, Riverside has combined observations from several of the world’s most powerful telescopes to carry out one of the largest studies yet of molecular gas the raw material which fuels star formation throughout the universe in three of the most distant clusters of galaxies ever found, detected as they appeared when the universe was only four billion years old.
Clusters are rare regions of the universe consisting of tight groups of hundreds of galaxies containing trillions of stars, as well as hot gas and mysterious dark matter. First, the research team used spectroscopic observations from the W. M. Keck Observatory on Mauna Kea, Hawai’i, and the Very Large Telescope in Chile that confirmed 11 galaxies were star-forming members of the three massive clusters. Next, the researchers took images through multiple filters from NASA’s Hubble Space Telescope, which revealed a surprising diversity in the galaxies’ appearance, with some galaxies having already formed large disks with spiral arms.
One of the telescopes the SpARCS scientists used is the extremely sensitive Atacama Large Millimeter Array (ALMA) telescope capable of directly detecting radio waves emitted from the molecular gas found in galaxies in the early universe. ALMA observations allowed the scientists to determine the amount of molecular gas in each galaxy, and provided the best measurement yet of how much fuel was available to form stars.
The researchers compared the properties of galaxies in these clusters with the properties of “field galaxies” (galaxies found in more typical environments with fewer close neighbors). To their surprise, they discovered that cluster galaxies had higher amounts of molecular gas relative to the amount of stars in the galaxy, compared to field galaxies. The finding puzzled the team because it has long been known that when a galaxy falls into a cluster, interactions with other cluster galaxies and hot gas accelerate the shut off of its star formation relative to that of a similar field galaxy (the process is known as environmental quenching).
“This is definitely an intriguing result,” said Gillian Wilson, a professor of physics and astronomy at UC Riverside and the leader of the SpARCS collaboration. “If cluster galaxies have more fuel available to them, you might expect them to be forming more stars than field galaxies, and yet they are not.”
Noble, a SpARCS collaborator and the study’s leader, suggests several possible explanations: It is possible that something about being in the hot, harsh cluster environment surrounded by many neighboring galaxies perturbs the molecular gas in cluster galaxies such that a smaller fraction of that gas actively forms stars. Alternatively, it is possible that an environmental process, such as increased merging activity in cluster galaxies, results in the observed differences between the cluster and field galaxy populations.
“While the current study does not answer the question of which physical process is primarily responsible for causing the higher amounts of molecular gas, it provides the most accurate measurement yet of how much molecular gas exists in galaxies in clusters in the early universe,” Wilson said.
The SpARCS team has developed new techniques using infrared observations from NASA’s Spitzer Space Telescope to identify hundreds of previously undiscovered clusters of galaxies in the early universe. In the future, they plan to study a larger sample of clusters. The team has recently been awarded additional time on ALMA, the W. M. Keck Observatory, and the Hubble Space Telescope to continue investigating how the neighborhood in which a galaxy lives determines for how long it can form stars.
The first in-car measurements of exposure to pollutants that cause oxidative stress during rush hour commutes has turned up potentially alarming results. The levels of some forms of harmful particulate matter inside car cabins was found to be twice as high as previously believed.
Most traffic pollution sensors are placed on the ground alongside the road and take continuous samples for a 24-hour period. Exhaust composition, however, changes rapidly enough for drivers to experience different conditions inside their vehicles than these roadside sensors. Long-term sampling also misses nuanced variabilities caused by road congestion and environmental conditions.
To explore what drivers are actually exposed to during rush hour, researchers from Duke University, Emory University and the Georgia Institute of Technology strapped specially designed sampling devices into the passenger seats of cars during morning rush hour commutes in downtown Atlanta.
The devices detected up to twice as much particulate matter as the roadside sensors. The team also found that the pollution contained twice the amount of chemicals that cause oxidative stress, which is thought to be involved in the development of many diseases including respiratory and heart disease, cancer, and some types of neurodegenerative diseases.
“We found that people are likely getting a double whammy of exposure in terms of health during rush-hour commutes,” said Michael Bergin, professor of civil and environmental engineering at Duke. “If these chemicals are as bad for people as many researchers believe, then commuters should seriously be rethinking their driving habits.”
For the experiment, Roby Greenwald, a research assistant professor at Emory at the time, built a sampling device that draws in air at a similar rate to human lungs to provide detectable levels of pollution. The device was then secured to the passenger seats of more than 30 different cars as they completed more than 60 rush hour commutes.
Some drivers took highway routes while others stuck to busy thoroughfares in downtown Atlanta. While other details like speed and having windows rolled down varied, all of the sampling found more risk in air exposure than previous studies conducted with roadside sampling devices.
“There are a lot of reasons an in-car air sample would find higher levels of certain kinds of air pollution,” said Heidi Vreeland, a doctoral student in Bergin’s lab and first author of the paper. “The chemical composition of exhaust changes very quickly, even in the space of just a few feet. And morning sun heats the roadways, which causes an updraft that brings more pollution higher into the air.”
Reactive oxygen species found by this study can cause the body to produce chemicals to deal with the reactive oxygen. Particulate matter causes the same response. In combination, the exposure triggers an overreaction that can be destructive to healthy cells and DNA.
Oxidative stress — the phenomenon antioxidant foods are supposed to address — is thought to play a role in a wide range of diseases including Asperger’s syndrome, ADHD, cancer, Parkinson’s disease, Alzheimer’s disease, atherosclerosis, heart failure and heart attack, sickle cell disease, autism, infection, chronic fatigue syndrome and depression.
“There’s still a lot of debate about what types of pollution are cause for the biggest concern and what makes them so dangerous,” Bergin said. “But the bottom line is that driving during rush hour is even worse than we thought.”
“My two cents is that this is really an urban planning failure,” said Greenwald, who is now an assistant professor of environmental health at Georgia State University. “In the case of Atlanta, the poor air quality on the highways is due to the fact that 6 million people live in the metro area, and most of them have little choice but to get into an automobile to go to work or school or the store or wherever. Auto-centric transportation plans do not scale well to cities of this size, and this is one more example of how traffic negatively affects your health.”
Imagine rescuers searching for people in the rubble of a collapsed building. Instead of digging through the debris by hand or having dogs sniff for signs of life, they bring out a small, air-tight cylinder. They place the device at the entrance of the debris and flip a switch. From one end of the cylinder, a tendril extends into the mass of stones and dirt, like a fast-climbing vine. A camera at the tip of the tendril gives rescuers a view of the otherwise unreachable places beneath the rubble.
This is just one possible application of a new type of robot created by mechanical engineers at Stanford University, detailed in a June 19 Science Robotics paper. Inspired by natural organisms that cover distance by growing — such as vines, fungi and nerve cells the researchers have made a proof of concept of their soft, growing robot and have run it through some challenging tests.
“Essentially, we’re trying to understand the fundamentals of this new approach to getting mobility or movement out of a mechanism,” explained Allison Okamura, professor of mechanical engineering and senior author of the paper. “It’s very, very different from the way that animals or people get around the world.”
To investigate what their robot can do, the group created prototypes that move through various obstacles, travel toward a designated goal, and grow into a free-standing structure. This robot could serve a wide range of purposes, particularly in the realms of search and rescue and medical devices, the researchers said.
A growing robot
The basic idea behind this robot is straightforward. It’s a tube of soft material folded inside itself, like an inside-out sock, that grows in one direction when the material at the front of the tube everts, as the tube becomes right-side-out. In the prototypes, the material was a thin, cheap plastic and the robot body everted when the scientists pumped pressurized air into the stationary end. In other versions, fluid could replace the pressurized air.
What makes this robot design extremely useful is that the design results in movement of the tip without movement of the body.
“The body lengthens as the material extends from the end but the rest of the body doesn’t move,” explained Elliot Hawkes, a visiting assistant professor from the University of California, Santa Barbara and lead author of the paper. “The body can be stuck to the environment or jammed between rocks, but that doesn’t stop the robot because the tip can continue to progress as new material is added to the end.”
The group tested the benefits of this method for getting the robot from one place to another in several ways. It grew through an obstacle course, where it traveled over flypaper, sticky glue and nails and up an ice wall to deliver a sensor, which could potentially sense carbon dioxide produced by trapped survivors. It successfully completed this course even though it was punctured by the nails because the area that was punctured didn’t continue to move and, as a result, self-sealed by staying on top of the nail.
In other demonstrations, the robot lifted a 100-kilogram crate, grew under a door gap that was 10 percent of its diameter and spiraled on itself to form a free-standing structure that then sent out a radio signal. The robot also maneuvered through the space above a dropped ceiling, which showed how it was able to navigate unknown obstacles as a robot like this might have to do in walls, under roads or inside pipes. Further, it pulled a cable through its body while growing above the dropped ceiling, offering a new method for routing wires in tight spaces.
“The applications we’re focusing on are those where the robot moves through a difficult environment, where the features are unpredictable and there are unknown spaces,” said Laura Blumenschein, a graduate student in the Okamura lab and co-author of the paper. “If you can put a robot in these environments and it’s unaffected by the obstacles while it’s moving, you don’t need to worry about it getting damaged or stuck as it explores.”
Some iterations of these robots included a control system that differentially inflated the body, which made the robot turn right or left. The researchers developed a software system that based direction decisions on images coming in from a camera at the tip of the robot.
A primary advantage of soft robots is that they can be safer than hard, rigid robots not only because they are soft but also because they are often lightweight. This is especially useful in situations where a robot could be moving in close quarters with a person. Another benefit, in the case of this robot, is that it is flexible and can follow complicated paths. This, however, also poses some challenges.
Joey Greer, a graduate student in the Okamura lab and co-author of the paper, said that controlling a robot requires a precise model of its motion, which is difficult to establish for a soft robot. Rigid robots, by comparison, are much easier to model and control, but are unusable in many situations where flexibility or safety is necessary. “Also, using a camera to guide the robot to a target is a difficult problem because the camera imagery needs to be processed at the rate it is produced. A lot of work went into designing algorithms that both ran fast and produced results that were accurate enough for controlling the soft robot,” Greer said.
Going big — and small
As it exists now, the scientists built the prototype by hand and it is powered through pneumatic air pressure. In the future, the researchers would like to create a version that would be manufactured automatically. Future versions may also grow using liquid, which could help deliver water to people trapped in tight spaces or to put out fires in closed rooms. They are also exploring new, tougher materials, like rip-stop nylon and Kevlar.
The researchers also hope to scale the robot much larger and much smaller to see how it performs. They’ve already created a 1.8 mm version and believe small growing robots could advance medical procedures. In place of a tube that is pushed through the body, this type of soft robot would grow without dragging along delicate structures.
In saliva, scientists have found hints that a “ghost” species of archaic humans may have contributed genetic material to ancestors of people living in Sub-Saharan Africa today.
The research adds to a growing body of evidence suggesting that sexual rendezvous between different archaic human species may not have been unusual.
Past studies have concluded that the forebears of modern humans in Asia and Europe interbred with other early hominin species, including Neanderthals and Denisovans. The new research is among more recent genetic analyses indicating that ancient Africans also had trysts with other early hominins.
“It seems that interbreeding between different early hominin species is not the exception — it’s the norm,” says Omer Gokcumen, PhD, an assistant professor of biological sciences in the University at Buffalo College of Arts and Sciences.
“Our research traced the evolution of an important mucin protein called MUC7 that is found in saliva,” he says. “When we looked at the history of the gene that codes for the protein, we see the signature of archaic admixture in modern day Sub-Saharan African populations.”
The study was led by Gokcumen and Stefan Ruhl, DDS, PhD, a professor of oral biology in UB’s School of Dental Medicine.
A tantalizing clue in saliva
The scientists came upon their findings while researching the purpose and origins of the MUC7 protein, which helps give spit its slimy consistency and binds to microbes, potentially helping to rid the body of disease-causing bacteria.
As part of this investigation, the team examined the MUC7 gene in more than 2,500 modern human genomes. The analysis yielded a surprise: A group of genomes from Sub-Saharan Africa had a version of the gene that was wildly different from versions found in other modern humans.
The Sub-Saharan variant was so distinctive that Neanderthal and Denisovan MUC7 genes matched more closely with those of other modern humans than the Sub-Saharan outlier did.
“Based on our analysis, the most plausible explanation for this extreme variation is archaic introgression — the introduction of genetic material from a ‘ghost’ species of ancient hominins,” Gokcumen says. “This unknown human relative could be a species that has been discovered, such as a subspecies of Homo erectus, or an undiscovered hominin. We call it a ‘ghost’ species because we don’t have the fossils.”
Given the rate that genes mutate during the course of evolution, the team calculated that the ancestors of people who carry the Sub-Saharan MUC7 variant interbred with another ancient human species as recently as 150,000 years ago, after the two species’ evolutionary path diverged from each other some 1.5 to 2 million years ago.
Why MUC7 matters
The scientists were interested in MUC7 because in a previous study they showed that the protein likely evolved to serve an important purpose in humans.
In some people, the gene that codes for MUC7 holds six copies of genetic instructions that direct the body to build parts of the corresponding protein. In other people, the gene harbors only five sets of these instructions (known as tandem repeats).
Prior studies by other researchers found that the five-copy version of the gene protected against asthma, but Gokcumen and Ruhl did not see this association when they ran a more detailed analysis.
The new study did conclude, however, that MUC7 appears to influence the makeup of the oral microbiome, the collection of bacteria within the mouth. The evidence for this came from an analysis of biological samples from 130 people, which found that different versions of the MUC7 gene were strongly associated with different oral microbiome compositions.
“From what we know of MUC7, it makes sense that people with different versions of the MUC7 gene could have different oral microbiomes,” Ruhl says. “The MUC7 protein is thought to enhance the ability of saliva to bind to microbes, an important task that may help prevent disease by clearing unwanted bacteria or other pathogens from the mouth.”