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ScienceBlog.com: 7 Stories to Start Your Day
- Navy Researchers Look for Safer Firefighting Foams
- Zeroing in on baby exoplanets could reveal how they form
- Side effects mild, brief with single antidepressant dose of intravenous ketamine
- Omega-3 shows protection against heart disease-related death, without prostate cancer risk
- Schools less important than parents in determining higher education aspirations
- Clearing damaged cells out of the body helps heal diabetics’ blood vessels
- Researchers bring gaming to autonomous vehicles
|Navy Researchers Look for Safer Firefighting Foams
Posted: 18 Nov 2019 05:56 AM PST
Firefighting foams — called aqueous film-forming foams — are used by the military to rapidly extinguish liquid fuel fires on airplanes and ships.
These foams contain fluorine in the form of per- and polyfluoroalkyl substances, or PFAS. PFAS chemicals work as a surfactant — they lower the surface tension of water, allowing the foam to more effectively cut off the oxygen that feeds a fuel fire.
According to the Environmental Protection Agency, PFAS is found in many products, such as clothing, carpets, fabrics for furniture, adhesives, paper packaging for food, and heat-resistant and non-stick cookware. PFAS chemicals are persistent in the environment and in the human body — meaning they don’t break down and they can accumulate over time. There is evidence that exposure to PFAS can lead to adverse human health effects, the EPA says.
Naval Research Lab scientists routinely test fluorine-free foams at Chesapeake Beach as part of their effort to find a replacement firefighting foam that meets military requirements.
They also test foams that contain fluorine, because the military still uses them to fight real liquid fuel fires.
The military no longer uses these foams for training.
John Farley, director of fire test operations at the lab, demonstrated a test in the facility’s 28-square-foot fire tank.
First, workers put an inch of water into the tank. Next, they added two gallons of ethanol-free gasoline, which floats on top of the water. The water helps to protect the test pan and ensures the test area is completely covered with fuel.
A worker then ignites the fuel, which produces a 5-megawatt fire. Farley said researchers then wait 10 seconds before attempting to extinguish the blaze with the foam, so the fire maintains a consistent burn.
The foam comes out of a nitrogen-pressurized nozzle at a set rate, so test results are consistent, he said.
During the test, Farley pushes the foam around the pool of fire to separate the vapor from the pool of gas. He said the gas in the pool doesn’t burn, just the vapor. Also, the foam barrier minimizes radiant heat going back into the fuel.
The military’s standard for a successful product, called MIL-SPEC, requires that a fire of the size of the test fire must be extinguished within 30 seconds.
Since the foam used contained fluorine, it met the MIL-SPEC with an extinction time of 27 seconds, Farley said.
After the fire was extinguished, a foam layer floats over the fuel and water. At this point, researchers perform a second test — called a burn back — in which a bucket of gasoline is set in the middle of the tank and ignited.
The purpose of the burn back test is to measure how long it takes the foam to degrade and the fire to reignite over the pool.
After the test is over, Farley said a sample of the foam is measured by a dynamic foam analyzer, which computes the geometric structure of the foam.
If an effective firefighting foam is developed, the structure of the foam will be informative, particularly, since commercially developed foam makers don’t disclose their ingredients, he said.
Farley said the lab also conducts tests using the fluorine-free commercial foams. In a recent test, one foam being tested took 47 seconds to extinguish the fire, and the other took nearly one minute. Since neither met the MIL-SPEC of 30 seconds, they both failed.
After each test, workers wash the foam down with water and collect it inside a tank for incineration for safe disposal.
During all testing, the Annapolis, Maryland, fire marshal is present to ensure the tests are conducted safely.
Farley said each type of foam is tested 23 times — 22 in the 28-square-foot tank and once in the lab’s 58-square-foot tank.
He said he’s confident that a safe and effective firefighting foam will be developed in the years ahead.
|Zeroing in on baby exoplanets could reveal how they form
Posted: 18 Nov 2019 05:55 AM PST
Twenty-four years ago, Swiss astronomers Michel Mayor and Didier Queloz discovered the first planet orbiting a sun-like star outside our solar system – a milestone recognised by this year’s Nobel prize in physics. Today we know of thousands more ‘exoplanets’, and researchers are now trying to understand when and how they form. The known exoplanets … Read more
|Side effects mild, brief with single antidepressant dose of intravenous ketamine
Posted: 18 Nov 2019 05:52 AM PST
National Institutes of Health researchers found that a single, low-dose ketamine infusion was relatively free of side effects for patients with treatment-resistant depression. Elia Acevedo-Diaz, M.D., Carlos Zarate, M.D., and colleagues at the NIH’s National Institute of Mental Health (NIMH) report their findings in the Journal of Affective Disorders.
Studies have shown that a single, subanesthetic-dose (a lower dose than would cause anesthesia) ketamine infusion can often rapidly relieve depressive symptoms within hours in people who have not responded to conventional antidepressants, which typically take weeks or months to work. However, widespread off-label use of intravenous subanesthetic-dose ketamine for treatment-resistant depression has raised concerns about side effects, especially given its history as a drug of abuse.
“The most common short-term side effect was feeling strange or loopy,” said Acevedo-Diaz, of the Section on the Neurobiology and Treatment of Mood Disorders, part of the NIMH Intramural Research Program (IRP) in Bethesda, Maryland. “Most side effects peaked within an hour of ketamine administration and were gone within two hours. We did not see any serious, drug-related adverse events or increased ketamine cravings with a single-administration.”
The researchers compiled data on side effects from 163 patients with major depressive disorder or bipolar disorder and 25 healthy controls who participated in one of five placebo-controlled clinical trials conducted at the NIH Clinical Center over 13 years. While past studies have been based mostly on passive monitoring, the NIMH IRP assessment involved active and structured surveillance of emerging side effects in an inpatient setting and used both a standard rating scale and clinician interviews. In addition to dissociative (disconnected, unreal) symptoms, the NIMH IRP assessment examined other potential side effects — including headaches, dizziness, and sleepiness. The study did not address the side effects associated with repeated infusions or long-term use.
Out of 120 possible side effects evaluated, 34 were found to be significantly associated with the treatment. Eight occurred in at least half of the participants: feeling strange, weird, or bizarre; feeling spacey; feeling woozy/loopy; dissociation; floating; visual distortions; difficulty speaking; and numbness. None persisted for more than four hours. No drug-related serious adverse events, cravings, propensity for recreational use, or significant cognitive or memory deficits were seen during a three-month follow-up.
To overcome the limitations associated with side effects and intravenous delivery, ongoing research efforts seek to develop a more practical rapid-acting antidepressant that works in the brain similarly to ketamine. These NIMH researchers, in collaboration with the National Institute on Aging, and the National Center for Advancing Translational Science, are planning a clinical trial of a ketamine metabolite that showed promise as a potentially more specific-acting treatment in pre-clinical studies. Meanwhile, the U.S. Food and Drug Administration earlier this year approved an intranasal form of ketamine called esketamine, which can be administered to adults with treatment-resistant depression in a certified doctor’s office or clinic.
|Omega-3 shows protection against heart disease-related death, without prostate cancer risk
Posted: 18 Nov 2019 05:51 AM PST
Should you take omega-3 pills? Or try to have two to servings of omega-3 rich fish a week, as the American Heart Association recommends? It may seem a bit murky if you follow headlines about nutrition and health.
That’s why researchers at the Intermountain Healthcare Heart Institute continue to research the potential benefits and risks of this popular supplement, especially when it comes to prostate cancer risk and heart health.
The Intermountain research team presented two new studies about omega-3s at the 2019 American Heart Association Scientific Sessions in Philadelphia on Nov. 17, 2019.
In one study, the Intermountain research team identified 87 patients who were part of the Intermountain INSPIRE Registry and had developed prostate cancer. These patients were also tested for plasma levels of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), which are two common omega-3 fatty acids.
When compared to a matched control group of 149 men, the researchers found that higher omega-3 levels were not linked with elevated prostate cancer risk.
Viet T. Le, MPAS, PA, researcher and physician assistant at the Intermountain Healthcare Heart Institute, said they undertook this study in light of findings from a 2013 paper from the Journal of the National Cancer Institute that suggested a possible link between higher omega-3 plasma levels and the development of prostate cancer, one that has been debated since publication.
“If I’m recommending omega-3 for my patients to save their hearts, I want to make sure I’m not putting them at risk for prostate cancer,” said Le. “Our study found no evidence of a link between the two.”
In the second study presented at the 2019 American Heart Association Scientific Sessions, the Intermountain researchers looked at 894 patients undergoing coronary angiography (a test that shows how blood flows through the arteries in the heart).
These patients had no prior history of heart attack or coronary artery disease, however upon their first angiogram, about 40% of those patients had severe disease and about 10% had three-vessel disease, Le said.
Researchers also measured patients’ plasma levels of omega-3 metabolites, including DHA and EPA. Those patients were then followed to see who had subsequent heart attack, stroke, heart failure, or who died.
Researchers found that patients who higher rates of omega-3 metabolites had lower risk of those follow up adverse effects regardless of whether they had severe disease or not on their initial angiogram.
“This study is important because we looked at how omega-3 helps patients who have already developed disease, and its effects on survival – both in getting to the first angiography to be diagnosed (vs. having a heart attack or worse before even knowing they have heart disease) and thereafter,” said Le.
“While a seeming association between higher plasma omega-3 levels and the findings of severe heart disease upon initial angiogram might raise alarms that omega-3 isn’t beneficial, they did live to see a doctor and get diagnosed,” Le added. “And we saw a link between higher levels of omega-3 and their survival rate thereafter.”
|Schools less important than parents in determining higher education aspirations
Posted: 18 Nov 2019 05:50 AM PST
A new study shows that the elementary school a child attends has almost no influence on their desire to progress to higher education – as factors including parental aspirations, academic support from their mother and having a desk to work on are much more important.
Published in the journal Educational Studies, the findings of the research looking at 1,000 pupils showed that school and class size, the grade point average of the school and property prices, had little influence on the desire to continue to higher education.
The research was carried out by Josip Šabi? and Boris Joki? at the Centre for Educational Research and Development of the Institute for Social Research in Zagreb, Croatia, and was supported by the Croatian Science Foundation. The authors wanted to discover the main factors affecting pupils’ intention to continue to higher education as they reach the end of elementary school.
In Croatia, children attend elementary schools up to age 14-15, at which point they move on to a secondary school. Here, they can either study for a four-year diploma, after which they have the option of applying for university, or a three-year diploma, which prepares pupils for work but does not permit them to apply for university.
To find out children’s aspirations, they asked just over 1,000 pupils at 23 elementary schools in Zagreb to complete three separate questionnaires during their last two years at elementary school. These questionnaires asked them whether they would like to continue to higher education, as well as about their parents and home life. There were questions about their parents’ aspirations for them, the level of academic support they received from each of their parents, whether they had their own room, computer and desk, and whether they enjoyed school.
The researchers also obtained information on the pupils’ academic grades, as well as on the size of each school and its classes, the grade point average for each school, and property prices in the area around each school as a measure of socioeconomic status. Finally, they performed statistical analyses on these responses to determine which factors were most closely related with a desire to continue on to higher education.
This revealed that none of the school-level factors, including school and class size, grade point average of the school and property prices, had any influence on the desire to continue to higher education. In contrast, several factors related to parents and home life, such as parental educational aspirations, maternal academic support and having a desk to work on, did have an influence. As did gender, with girls more likely than boys to want to continue to higher education. And while school-level factors didn’t have any influence, performance at school did: high academic grades were the single strongest predictor of a pupil’s desire to continue to higher education, while enjoying school was also an important factor.
“The major finding arising from the present study is that none of the school level variables used in our analysis contributes to the explanation of pupils’ aspirations for higher education,” said Šabi?. “In other words, pupils who have similar individual characteristics but attend different schools will likely hold similar aspirations for higher education.
“Another important finding is that parents can influence their child’s aspirations by expressing their expectations regarding the child’s educational path and by providing the basic conditions for completing homework and learning (i.e. a desk to work on).”
This is the first study to investigate the influence of such a large number of factors on the desire to progress to higher education, and while it focused on pupils in Croatia, Šabi? and Joki? think their findings could apply to other similar educational systems.
|Clearing damaged cells out of the body helps heal diabetics’ blood vessels
Posted: 18 Nov 2019 05:49 AM PST
Research published today in Experimental Physiology shows that ramping up one of the body’s waste disposal system, called autophagy, helps heal the blood vessels of diabetics.
Complications with blood vessels (known as vascular complications) are major risk factors for morbidity and mortality in the diabetic patients. These complications are divided into microvascular (damage to small blood vessels) and macrovascular (damage to larger blood vessels).
Microvascular complications include damage to eyes which can lead to blindness, to kidneys which can lead to renal failure and to nerves leading to impotence and diabetic foot disorders (which lead to amputation).
Autophagy is the body’s way of cleaning out damaged cells, in order to regenerate newer, healthier cells. Impaired autophagy has been reported to be involved in Type 2 diabetes, but researchers weren’t sure why.
This study, from researchers at the Yonsei University College of Medicine is the first to demonstrate a protective role of autophagy stimulation in the vascular dysfunction of Type 2 diabetes. The researchers used mice that have similar features as human Type 2 diabetes, and measured the diameter of small arteries, which is an indication of how healthy the arteries are.
Soo-Kyoung Choi, first author on the study said: “We are excited about these results because our study suggests that targeting autophagy could be a potential target for the treatment of vascular problems in Type 2 diabetic patients.”
|Researchers bring gaming to autonomous vehicles
Posted: 18 Nov 2019 05:47 AM PST
Researchers have designed multiplayer games occupants of autonomous vehicles can play with other players in nearby self-driving cars.
A new study, led by researchers from the University of Waterloo details three games created for level three and higher semi-autonomous vehicles. The researchers also made suggestions for many exciting types of in-car games for future exploration.
Level three and higher semi-autonomous vehicles are those that have, at minimum, environmental detection capabilities and can make informed decisions for themselves.
“As autonomous vehicles start to replace conventional vehicles, occupants will have much more free time than they used to,” said Matthew Lakier, a PhD student in Waterloo’s School of Computer Science. “You could use time spent in commute to read a book, watch a movie, get ahead on work, or browse the internet. Still, not everything you do has to be all isolated.
“You will be able to play games with other people in autonomous vehicles nearby when the car is driving itself. The games will be imposed on top of the actual world, so drivers won’t have to take their eyes off the road.”
Self-driving cars have many intelligent technologies that help to keep them safe, and the researchers envision that in the future, vehicle-to-vehicle (V2V) communication and heads-up displays (HUDs) will also become standard features. V2V enables cars to let each other know where they are relative to each other on the road, and HUDs on the windshield keep drivers aware of the car’s speed and road conditions.
In developing the three games, the researchers first undertook an extensive literature review to identify gaps in previous research done about autonomous vehicles and found that not much attention has been given to cross-car games.
They then developed a virtual reality (VR) driving simulator to render the car cabin, outside environment, and roadway with artificially controlled cars and intelligent computer-controlled players. The VR driving simulator is designed as a framework to enable rapid prototyping of in-car games that leverage future technologies like V2V, full window HUDs, head tracking, and different input methods.
Twelve participants evaluated the three cross-car games. They played the games, with occasional take-over tasks, completed the Player Experience Inventory questionnaire to measure player experience, and answered questions in a semi-structured interview.
“Overall, the participants rated the games highly in immersion, there was a positive response to the incorporation of HUDs in the games, and the different game styles did not significantly impact the take-over task completion time. All games were popular for different reasons,” said Lakier, a member of Waterloo’s Human-Computer Interaction (HCI) Lab.
“People were happy to play with strangers. So, for example, they said they could form impromptu relationships with other people on the road.”