Culture

Researchers at University of California San Diego School of Medicine have developed a microbial detection technique so sensitive that it allows them to detect as few as 50-100 bacterial cells present on a surface. What's more, they can test samples more efficiently -- up to hundreds of samples in a single day.

The technique was validated by sampling hundreds of surfaces in three different environments: the Spacecraft Assembly Facility at NASA's Jet Propulsion Laboratory at California Institute of Technology; the neonatal intensive care unit (NICU) in Jacobs Medical Center at UC San Diego Health; and an endangered white abalone rearing facility at National Oceanic and Atmospheric Administration (NOAA)'s Southwest Fisheries Science Center in La Jolla, Calif.

Details of the technique, called KatharoSeq, are published March 13 in the journal mSystems. ("Katharos" is Greek for "pure," and "Seq" is short for sequencing.) KatharoSeq has already revealed new insights about the three testing sites that could help optimize how the Mars 2020 Rover is assembled, how bacteria are tracked in hospitals, and how endangered white abalone are raised and returned to the wild.

"The more we know about the microbial communities in a given environment, the more likely it is we can reshape them to improve environmental and human health," said senior author Rob Knight, PhD, professor of pediatrics and computer science and engineering, and director of the Center for Microbiome Innovation at UC San Diego.

Here's what KatharoSeq has revealed so far:

The Spacecraft Assembly Facility at Jet Propulsion Laboratory is where NASA builds spacecraft and machinery to be launched into space. Engineers and staff must account for every biological organism sent into space in order to prevent contamination of other planets.

In this part of the study, Knight's team wondered if KatharoSeq might be able to detect microbes in what is thought to be a sterile facility. Of the three sites tested, the Spacecraft Assembly Facility had the lowest microbial diversity. But bacteria were still present -- KatharoSeq detected 32 types. The most abundant type was Acinetobacter Iwoffi, which is associated with human foot traffic.

Knight's team will now work with Jet Propulsion Laboratory staff to create a map of the microbes living in the facility over the next six months, including the Mars 2020 Rover. Their goal is to send a sterile rover to Mars.

The NICU at Jacobs Medical Center at UC San Diego Health is relatively new -- the 245-bed advanced specialty hospital opened in La Jolla in late 2016, about four months before samples were collected for this study. The 52-room NICU was designed to give each baby and his or her family a private room, with the idea that it would not only provide a better patient experience, but also prevent the spread of infection among this vulnerable population.

In this study, the NICU samples contained more bacterial species than the Spacecraft Assembly Facility, but fewer than the white abalone rearing facility. Consistent with other hospital findings, the researchers using KatharoSeq found that staphylococcal bacteria were the most prominent type in the facility, the majority of which were the harmless skin resident Staphylococcus epidermidis.

The NICU has two sections -- one with higher acuity (a higher health care provider-to-patient ratio) and one with lower acuity. The team found more staphylococcal bacteria on the surfaces of the high acuity wing, which at the time of the study correlated with a higher culture rate in that area (six positive cultures in 14 high-acuity rooms, vs. six in five of 37 low-acuity rooms).

Using KatharoSeq, surfaces in one of the NICU rooms tested positive for the bacterium Serratia marcescens. Unbeknownst to Knight's team at the time, the infant staying in that room had had a lung infection with that bacterium. But they noted that the bacteria were absent from the rooms on either side, supporting the assumption that private patient rooms provide a barrier to infection.

"All hospitals have bacteria," Knight said. "But this is the kind of information we don't yet have -- which bacteria are found where, and for how long. Pathogen monitoring currently requires taking samples from patients and sending them to be cultured, where lab technicians wait to see which bacteria grow in a petri dish. Being able to monitor and predict pathogens by routine, noninvasive sampling of the built environment and sequencing to identify the bacteria, rather than waiting for cultures to grow, could be a useful approach for identifying potential hotspots of transmission that are currently unknown."

In the future, co-author Jae Kim, MD, PhD, associate clinical professor of pediatrics and nutrition medical director of the Supporting Premature Infant Nutrition Program, and his team hope to investigate probiotic interventions in the NICU. They want to know if treating patients with beneficial bacteria might help prevent colonization with pathogenic bacteria over time, both on the patient and within the built environment of the room.

NOAA's Southwest Fisheries Science Center raises endangered white abalone to help reestablish their populations in the wild. These shellfish were the first marine invertebrate added to the endangered species list -- in the late 1990s. Since their populations have declined in part due to a withering syndrome caused by a type of Rickettsia bacteria, infection control is vitally important to the rearing facility, particularly when abalone are transferred in from other aquariums. The white abalone tank receives seawater that has been UV-treated and filtered.

In this study, KatharoSeq detected a diverse microbial community in the white abalone tanks. The researchers found many types of marine bacteria, including symbiotic species that may help the fish digest algae. The white abalone had more bacteria in common with their surrounding environment than with the nearby red abalone. But researchers did not detect any of the troubling Rickettsia. Going forward, Knight's team hopes to work with the rearing facility to determine the optimal microbial make-up of the white abalone and its surrounding environment to improve transplantation success.

"When it comes to human and environmental health, sterile is not necessarily better," said co-author Russ Vetter, a senior scientist at NOAA Southwest Fisheries Science Center. "We want to compare wild and aquarium-raised abalone, and better understand how an aquarium-raised abalone's resident bacteria help or harm them once they are released into the ocean. Do they need a probiotic bath before release, or will a different diet to help prepare them? We don't know yet."

Technical details. The first author of this study, Jeremiah Minich, a graduate student working on his thesis in Knight's lab and in the lab of Eric E. Allen, PhD, associate professor at UC San Diego Scripps Institution of Oceanography, swabbed each of these sites while wearing protective gowning and gloves to avoid unintentional contamination of the environments. He took the samples back to the lab on dry ice, then ran them through the typical microbial DNA sequencing protocol: extract DNA from the samples, amplify microbe-specific "barcodes" known as 16S rRNA using a technique called polymerase chain reaction (PCR), run them through a sequencer and analyze the data.

What's new in KatharoSeq is that Minich integrated a sample pooling strategy, appropriate positive and negative controls, high-throughput DNA extraction and a magnetic bead-based DNA clean-up approach. Most researchers pass their samples through a filter in a column to purify DNA before sequencing, but Minich and team found that a lot of material is inadvertently lost that way. With KatharoSeq, the researchers improved their level of microbial detection by about two orders of magnitude and increased the rate at which they can process samples about five-fold, as compared to standard sampling and sequencing methods.

"We can get results as quickly as 48 hours after receiving a biological sample," Minich said. "And we think we could do it even faster once we scale it up and incorporate more automation into the KatharoSeq process."

The rising prevalence of dental erosion and dentin hypersensitivity has led to the emergence of more and more toothpastes on the market that claim to treat these problems. While no such toothpaste existed 20 years ago, today, many brands with different attributes are being offered.

However, a study conducted at the University of Bern in Switzerland with the participation of a researcher supported by a scholarship from the São Paulo Research Foundation - FAPESP showed that none of the nine analyzed toothpastes was capable of mitigating enamel surface loss, a key factor in tooth erosion and dentin hypersensitivity.

"Research has shown that dentin must be exposed with open tubules in order for there to be hypersensitivity, and erosion is one of the causes of dentin exposure. This is why, in our study, we analyzed toothpastes that claim to be anti-erosive and/or desensitizing," said Samira Helena João-Souza, a PhD scholar at the University of São Paulo's School of Dentistry (FO-USP) in Brazil and first author of the article.

According to an article published in Scientific Reports, all of the tested toothpastes caused different amounts of enamel surface loss, and none of the toothpastes afforded protection against enamel erosion and abrasion.

The authors of the study stressed that these toothpastes perform a function but that they should be used as a complement, not as a treatment, strictly speaking. According to João-Souza, at least three factors are required: treatment prescribed by a dentist, use of an appropriate toothpaste, and a change in lifestyle, especially diet.

"Dental erosion is multifactorial. It has to do with brushing, and above all, with diet. Food and drink are increasingly acidic as a result of industrial processing", she said.

The researcher highlights that dental erosion is a chronic loss of dental hard tissue caused by acid without bacterial involvement - unlike caries, which is bacteria-related. When it is associated with mechanical action, such as brushing, it results in erosive wear. In these situations, patients typically experience discomfort when they drink or eat something cold, hot or sweet.

"They come to the clinic with the complaint that they have caries, but actually, the problem is caused by dentin exposure due to improper brushing with [a] very abrasive toothpaste, for example, combined with frequent consumption of large amounts of acidic foods and beverages," said Professor Ana Cecília Corrêa Aranha, João-Souza's supervisor and a co-author of the article.

In our clinical work, we see patients with this problem in the cervical region between [the] gum and tooth. The enamel in this region is thinner and more susceptible to the problem," she added.

Methodology

The scientists tested eight anti-erosive and/or desensitizing toothpastes and one control toothpaste, all of which are available from pharmacies and drugstores in Brazil or Europe.

The research simulated the effect of brushing once a day with exposure to an acid solution for five consecutive days on tooth enamel. The study used human premolars donated for scientific research purposes, artificial saliva, and an automatic brushing machine.

"We used a microhardness test to calculate enamel loss due to brushing with the toothpastes tested. The chemical analysis consisted of measuring toothpaste pH and levels of tin, calcium, phosphate and fluoride," João-Souza explained.

The physical analysis consisted of weighing the abrasive particles contained in the toothpastes, measuring their size, and testing wettability - the ease with which toothpaste mixed with artificial saliva could be spread on the tooth surface.

"During brushing with these toothpastes mixed with artificial saliva, we found that the properties of the toothpastes were different, so we decided to broaden the scope of the analysis to include chemical and physical factors. This [broadening] made the study more comprehensive," João-Souza said.

Statistically similar

All of the analyzed toothpastes caused progressive tooth surface loss in the five-day period. "None of them was better than the others. Indication will depend on each case. The test showed that some [toothpastes] caused less surface loss than others, but they all resembled the control toothpaste [for] this criterion. Statistically, they were all similar, although numerically, there were differences," Aranha said.

"We're now working on other studies relating to dentin in order to think about possibilities, given that none of these toothpastes was found capable of preventing dental erosion or dentin hypersensitivity, which is a cause of concern."

The researchers plan to begin a more specific in vivo study that will also include pain evaluations.

An electronic consultation system designed to reduce excessive wait times for appointments with specialists experienced exponential growth during a recent five-year period. The Champlain BASE eConsult service was created to provide primary care clinicians in Ontario, Canada with a range of high quality and timely (up to one week) specialty input. Unlike electronic consultation systems that provide direct links between clinicians, this service enables primary care clinicians to search a directory, select a specialist, and contact her/him through a secure channel. The system, created in 2010, had four completed eConsult cases in April, 2011 compared to 769 cases in April, 2016, with primary care clinicians submitting 14,105 cases to 56 specialties during the 5-year period. Specialties receiving the highest number of eConsults were dermatology (17 percent); endocrinology, obstetrics/gynecology, and hematology (7 percent each); cardiology (6 percent); and neurology (6 percent). Specialists responded in a median of 21 hours; in 75 percent of cases they responded within three days. Self-reported billing time for specialists ranged from less than 10 minutes (in 48 percent of cases) to more than 20 minutes (4 percent of cases). By the end of the study period, approximately 80 percent of primary care clinicians in the region had adopted the eConsult service, which is poised for expansion across Canada. The study demonstrates that, once integrated into a practice's specialty referral workflow, the eConsult service has the potential to reduce wait times for specialty care.

Sustainability of a Primary Care-Driven eConsult Service
Clare Liddy, MD, MSc, CCFP, et al
C.T. Lamont Primary Health Care Research Centre, Ottawa, Ontario, Canada
http://www.annfammed.org/content/16/2/120.full

Male moths have evolved intricate scale arrangements on their antennae to enhance detection of female sex pheromones, which allows them to keep their antennae small enough to maximise flying, new research suggests.

The work was led by researchers at the University of Melbourne with RMIT University, Walter and Eliza Hall Institute, Beijing Forestry University and is published today [EMBARGO 1100 14 March AEDT] in Proceedings of the Royal Society B.

Charles Darwin was among the first to consider how the type of antenna might influence how male insects detect sex pheromones produced by females, said Professor Mark Elgar from the University of Melbourne's School of Biosciences.

"Darwin predicted that sexual selection, arising from competition among males, would favour more elaborate antennae in male moths, as they ensure more rapid detection of female sex pheromones.

"Moth sex pheromones are detected by receptors on structures called sensilla on the antennae.

"Conventional wisdom is that the feathery, bipectinate antennae in moths, arranged like two combs with numerous branches, provide a larger surface area to house the pheromone-detecting sensilla.

"But what we see in nature is that the majority of moth species have simple, filamentous-shaped antennae, which led us to ask why, if they are better at detecting sex pheromones, bipectinate antennae are less common in moths."

To understand this evolutionary dilemma, the team used scanning electron microscopy (SEM) to build finely detailed three-dimensional models of the structure of the filamentous antennae in Heliozelidae moths. Then they used computational fluid dynamics techniques to simulate the airflow field around the model antennae of moths of different sizes and scale arrangements.

Dr Qike Wang led the experimental work which used nanoparticles in the fluid dynamic model to represent common sex pheromones and microparticles to represent environmental particles such as dust.

"We found that the angle of the scales concentrated the signal molecules to the downwind side of the antennae," said Dr Wang

"By creating an area with slow airflow around the antennae, the scales ensure pheromones linger within the detection zone, thereby increasing the efficiency with which they interact with receptor."

"Furthermore, the scales are also effective at diverting away larger contaminating particles, such as dust. In a sense, they sift through the different particles only retaining the favourable ones."

"This is particularly important for species, like moths, that cannot groom the full length of their antennae."

The study found the effect of the scales on retaining sex pheromones is much greater for smaller than larger moths. For smaller moths with filamentous antennae, antennal scales improve signal detection by 25-48 per cent.

The team also found different types of scale arrangements, which ranged from those aligned parallel to antennae to those arranged in complete rings around the antennae, changed how well the scales functioned to concentrate sex pheromones to the receptor regions in the sensilla.

"The scales increase the diameter of the antennae and must, therefore, increase aerodynamic drag. We predict that the ability to find a mate through improved pheromone detection is likely to be a benefit that offsets this cost," said Professor Elgar.

"More complex, bipectinate antennae may be favoured in large moths because they offer an additional surface area that can support more sensilla and thus a greater capacity to perceive chemical signals. Larger moths may be less impacted by reduction in flight speed due to their greater size and power."

"It's fascinating that Darwin's theory is still supported, but we needed modern techniques such as electron microscopy and computational fluid dynamics to confirm that it is antennal scales, and not size that make them more effective and detecting those crucial sex pheromones," Professor Elgar said.

Funding from California's special tax for mental health services has allowed Los Angeles County to reach the seriously mentally ill and those at risk for mental illness with services and prevention efforts, lowering both homelessness and the need for psychiatric hospitalizations, while improving employment and wellbeing, according to a new RAND Corporation study.

The analysis found that from 2012 through 2016, the Los Angeles County Department of Mental Health provided prevention and early intervention services to almost 130,000 youth, and intensive clinical and social services designed to stabilize those who have serious psychiatric illnesses to almost 25,000 youth and adults.

"We found evidence that the services created in Los Angeles County under the Mental Health Services Act are reaching the people they intend to help, and those people are benefitting from the services provided," said Scott Ashwood, lead author of the report and a policy researcher at RAND, a nonprofit research organization.

California voters in 2004 approved Proposition 63, which created a 1 percent tax on all personal income over $1 million to provide expanded mental health services statewide.

Researchers from RAND and UCLA analyzed administrative data to evaluate two types of programs in Los Angeles County supported by the tax. The first is prevention and early intervention programs that aim to prevent the onset of mental illness and the related negative consequences. The second area evaluated was the county's full-service partnership program, which takes a "housing first" approach to improve residential stability and mental health outcomes for people with serious mental illness.

Funding from the Mental Health Services Act allowed the county Department of Mental Health to significantly expand both types of services to reach more people from a wider array of age groups.

The evaluation found that the prevention program provided services to about 130,000 youths, with 65 percent of those served being new clients. Hispanic and Asian youth served by the program had particularly good outcomes in comparison to other groups, although all racial/ethnic groups saw improvements.

"Helping young people can change the trajectory of their lives and potentially put them on a path where they experience less suffering, better relationships and more success in life," Ashwood said.

Researchers found that the number of people receiving services under the full-service partnership program rose over the study period, providing intensive housing support and other social services to about 25,000 adults and children during the period. Participants tended to have a severe diagnosis, such as suffering from schizophrenia or another psychotic disorder, and had a high likelihood of being homeless.

The rate of homelessness dropped sharply among those served by the program and participants also experienced less inpatient hospitalization for their mental health problems. The employment rate also increased among those receiving services, although the overall jobless rate among the group remained high.

Researchers recommend that the county Department of Mental Health revise some of its data collection methods to better document whether program participants are improving and whether best practices are being followed as services are delivered.

The evaluation did not include other county services supported by the Mental Health Services Act, such as primary prevention programs or outreach services, because those efforts do not have data readily available for review.

MINNEAPOLIS - Mar. 13, 2018 - Researchers from Children's Minnesota (Children's) and HealthPartners Institute have developed a new pediatric appendicitis risk calculator (pARC) to aid in the diagnosis of appendicitis. The calculator was developed as part of a $3.1 million, five-year grant from the National Institutes of Health (NIH).

In the April issue of Pediatrics, the researchers describe a novel method to calculate a patient's specific risk for appendicitis. With this new method, clinicians will be able to provide tailored medical and surgical guidance to a patient. In the study, researchers used data collected from ten pediatric emergency departments to develop the risk calculator and then independently validated the score using data from a single children's hospital. Potential benefits of using the new risk calculator include a reduction in the use of computed tomography (CT), more judicious utilization of ultrasound and a reduction in healthcare expenditures.

"This method is of great benefit to our patients and the health care system overall," said Dr. Anupam Kharbanda, co-Principal Investigator and chief of critical care services at Children's Minnesota. "In addition to being able to target our care specifically to each patient, we're also reducing the use of unnecessary medical tests and expenses. We're thrilled to have developed a new way to standardize care for children and adolescents with abdominal pain."

Abdominal pain is one of the most common reasons children visit the emergency department and appendicitis is the most frequent surgical emergency in pediatrics. CT is one of the most common ways clinicians diagnose appendicitis and CT scans are not only costly, but can also put pediatric patients at risk for radiation-induced injuries, especially because their bodies are smaller and organs more sensitive than adults. As a result, researchers at Children's and HealthPartners have sought methods to develop a safer, more cost-efficient way to determine the risk for appendicitis when a patient has presented at an emergency department with abdominal pain.

Children's and HealthPartners continue to collaborate on methods to improve the care of children in our community. The same researchers, along with colleagues from Kaiser Permanente Northern California, are conducting a 17-center trial to improve the care of pediatric patients who seek care in general emergency departments, including the six HealthPartners-affiliated emergency departments. This study will utilize the appendicitis risk calculator to guide care in the community setting.

RIVERSIDE, CA. - Here's a blind test taste like Pepsi never imagined.

Researchers at the University of California, Riverside, recently published a study of recycled wastewater that did not focus on its safety-which has long been established-but rather its taste.

After years of drought, the notion of drinking recycled wastewater has gained momentum in California. Thoughts turned to all the water being discarded--to supplementing "conventional" groundwater with recycled water.

But consumers were quick to flag the euphemism of "recycled." Some have even branded the technology "toilet to tap."

"It seems that this term (wastewater), and the idea of recycled water in general, evokes disgust reactions," said Daniel Harmon, a graduate student in psychology and the lead author in the study on water taste. The study published in print in the February edition of the journal Appetite.

However, Harmon added: "It is important to make recycled water less scary to people who are concerned about it, as it is an important source of water now and in the future."

The water's safety has been the source of most related research. The wastewater is treated using reverse osmosis. A preferred technology is called indirect potable reuse, or IDR. IDR reintroduces treated wastewater into groundwater supplies, where it re-enters the drinking water system. Six California water agencies already employ IDR. These include the Water Replenishment District of Southern California, the Orange County Water District, the Los Angeles County Department of Public Works, the Inland Empire Utilities District, the city of Los Angeles, and the city of Oxnard.

Studies have found IDR removes virtually all contaminants. But no one has considered its relative taste; at least, not in a blind taste test, and not in a scientific study.

The UCR study included 143 people, who were asked to compare IDR-treated tap water with conventional tap water and commercially bottled water. The waters were presented in similar cups and were unlabeled, hence the participants were "blind" to the source of the water. After tasting the water, participants ranked the samples' taste from one to five, then also in categories including texture, temperature, smell, and color.

The researchers weighed factors that influence taste perception.

There are genetic differences in taste sensitivity. That was gauged using a tried-and-true measure: paper strips coated with the chemical phenylthiocarbomide, or PTC. Those who find the strip's taste to be bitter are considered to have more sensitive taste.

Researchers also considered two personality traits that help determine water preference. These traits are referred to as "Openness to Experience" and "Neuroticism." Openness is how receptive people are to novel and diverse experiences. Neuroticism refers to anxiety and insecurity.

At the outset, researchers hypothesized the three waters would score equally. In fact, one emerged the least preferred.

"The groundwater-based water was not as well liked as IDR or bottled water," said Mary Gauvain, a professor of psychology at UC Riverside and co-author of the study. "We think that happened because IDR and bottled water go through remarkably similar treatment processes, so they have low levels of the types of tastes people tend to dislike."

The more nervous, anxious people in the study expressed the preference for IDR and bottled water, and were more negative about the more mineral-rich tap water. People more open to new experiences liked the three samples about the same.

Another surprise: Women were twice as likely to prefer bottled water as men.

The researchers' best guess: Women register higher "disgust reactions" than men, which means their reactions to tastes they dislike are more extreme. These disgust reactions are the subject of the team's next research paper.

In its conclusion, researchers suggest that favorable comparisons between reverse osmosis and bottled water may make consumers more amenable to drinking recycled wastewater. In particular, they suggest, marketing to women, who make most consumer purchasing decisions, should focus on these similarities, and also cater to women's demonstrated openness to new experiences.

"We think this research will help us find out what factors people pay attention to in their water decisions, and what populations need to be persuaded to drink IDR water and how to persuade them," Harmon said.

Researchers at the Intermountain Medical Center Heart Institute in Salt Lake City have found that incorporating underused, but available, imaging technologies more precisely predicts who's at risk for heart attacks and similar threats -- in time to prevent them.

For the study, researchers measured the level of calcium in the coronary arteries during stress testing using two common diagnostic tests -- positron emission tomography, or PET, and computed tomography, or CT -- to determine a patient's risk of heart disease.

"Typically, if you have chest pain, you come into the emergency department or see your doctor, and you may undergo a stress test to determine if you are suspected to have a blockage in your coronary arteries," said Viet Le, PA-C, lead author of the study, and a physician assistant and cardiovascular researcher in the Intermountain Medical Center Heart Institute.

"If you look at your coronary arteries like a hallway, the stress test essentially allows you to throw a ball down the hall, and if it makes it from point A to point B, there's no significant blockage," Le said. "If the hall is blocked and the ball doesn't roll all the way through, significant heart disease is likely."

Le, however, noted that can be misleading.

"Even if the ball makes it all the way down the hall, there may be boxes stacked up in the hallway, so the path is partially blocked, and if the boxes fall, you're in danger of a complete blockage. That's what testing for calcium does, it identifies existing disease. If we find calcium in your arteries, you're more likely to suffer a major adverse event, such as a heart attack or death, or you may require a stent or bypass surgery."

Researchers studies more than 8,000 patients at Intermountain Medical Center without a history of coronary artery disease, heart attack, or known restricted blood flow to the heart who came to a physician clinic or the hospital with symptoms of suspected heart disease and received a PET/CT imaging exam from 2013 to 2016.

Of those patients, researchers found that 53.2 percent had no calcium in the coronary arteries, while 46.8 percent did. Within 60 days, they found:

6 percent of patients with no calcium underwent coronary angiography, compared to 10.8 percent who had calcium.
8 percent of patients with no calcium went on to receive revascularization to restore blood flow to the heart, compared to 6.5 percent of patients who had calcium in their coronary arteries.
9 percent of patients with no calcium had a major adverse coronary artery event, such as a heart attack, compared to 6.0 percent of patients with calcium.
4 percent of patients with no calcium died, compared to 4.2 percent of patients with calcium

Results of the study will be presented during the 2018 American College of Cardiology Scientific Session in Orlando on March 12th at 9:30 a.m., ET.

More than 13,000 cardiologists and cardiovascular clinicians from around the world will be attending the scientific meeting.

"Conducting a PET/CT test to measure coronary artery calcium means clinicians can tell the difference between the potential risk of heart disease and actually having disease," Le said. "High blood pressure, diabetes, high cholesterol, and smoking are all risks of heart disease, yet many people who have those risks never have the disease or suffer an event. Coronary artery calcium is the disease -- and to an extent, it shows just how much of the disease is present."

The result of assessing calcium during a PET/CT stress test means care can be more precise while providing patients more incentive and motivation to improve their lifestyles.

"After a negative stress test, we may be likely to tell a patient, 'You're good, your symptoms today are not from your heart -- there's no coronary blockage,' and patients walk away feeling like Superman," Le said. "The coronary artery calcium PET/CT test allows us to recommend therapy sooner, if necessary. We can say, 'Well, the ball may have made it all the way down the hallway, but there's an obstruction lying in wait there, which means you've got heart disease. This isn't theoretical; you're at risk. You need to be more vigilant about exercise, diet, and your symptoms. We may need to initiate medical therapy'. We then can monitor those patients more aggressively to reduce their risk."

The PET/CT test also has the potential to proactively reduce healthcare costs -- since preventing a heart attack or similar event is the best, and least expensive, way to treat it. "Avoiding a heart attack is a huge economic benefit," Le said. "A similar benefit comes as clinicians prescribe medications more efficiently by identifying precisely who needs them."

The odds of a 22-year absence of mass shootings in Australia since 1996 gun reforms being due to chance are one in 200,000, new research reveals.

Published today in the Annals of Internal Medicine, scholars at the University of Sydney and Macquarie University used mathematical techniques to test the null hypothesis that the rate of mass shootings in Australia before and after the 1996 law reforms is unchanged.

The National Firearms Agreement, enacted after the Port Arthur massacre in Tasmania in which 35 died and another 23 were seriously injured, saw the destruction of more than a million firearms--perhaps a third of the country's private gun stock.

The Agreement included uniform gun registration, repudiation of self-defense as a legitimate reason to hold a firearm license, mandatory locked storage, a ban on mail order sales and standardized penalties, and the banning of semi-automatic rifles and pump action shot guns from civilian ownership.

Its provisions were subsequently enacted in national, state and territory legislation across Australia.

In the 18 years up to and including the Port Arthur massacre in 1996, there were 13-gun homicides in which five or more people died, not including the perpetrator. In the 22 years since, there have been no such incidents.

"Most people hear these starkly contrasting numbers and conclude that Australia's gun law reforms effectively stopped firearm massacres here," says the paper's lead author, Emeritus Professor Simon Chapman of the University of Sydney.

"However, some scholars and members of the gun lobby have argued that since mass shootings are relatively rare events, the concentration of incidents in one decade and their absence in another decade is merely a statistical anomaly."

For example, Australian researcher Dr Samara McPhedran writing in The Conversation said: "Mass shootings are rare events, and the long gap between incidents post-1996 may simply reflect a return to a more 'normal' state of affairs, similar to the years before 1987."

"This was no accident," says the new study's co-author Associate Professor Philip Alpers, from the University of Sydney. "Australia followed standard public health procedures to reduce the risk of multiple shooting events, and we can see the evidence. It worked.

"Gun lobby-affiliated and other researchers have been saying for years that mass shootings are such rare events it could have been a matter of luck they dropped off in the wake of Australia's gun control laws," says Alpers. "Instead, we found the odds against this hypothesis are 200,000 to one."

In related news, Tasmania's re-elected Premier has defended the Liberals' policy to relax the state's gun laws, despite an outcry from survivors of the Port Arthur shooting.

DURHAM, N.C. -- Some animals are quick-change artists. Take the hogfish, a pointy-snouted reef fish that can go from pearly white to mottled brown to reddish in a matter of milliseconds as it adjusts to shifting conditions on the ocean floor.

Scientists have long suspected that animals with quick-changing colors don't just rely on their eyes to tune their appearance to their surroundings -- they also sense light with their skin. But exactly how "skin vision" works remains a mystery.

Now, genetic analysis of hogfish reveals new evidence to explain how they do it. In a new study, Duke University researchers show that hogfish skin senses light differently from eyes.

The results suggest that light-sensing evolved separately in the two tissues, said Lori Schweikert, a postdoctoral scholar with Sönke Johnsen, biology professor at Duke.

With "dermal photoreception," as it is called, the skin doesn't enable animals to perceive details like they do with their eyes, Schweikert said. But it may be sensitive to changes in brightness or wavelength, such as moving shadows cast by approaching predators, or light fluctuations associated with different times of day.

Schweikert, Johnsen and Duke postdoctoral associate Bob Fitak focused on the hogfish, or Lachnolaimus maximus, which spends its time in shallow waters and coral reefs in the western Atlantic Ocean, from Nova Scotia to northern South America. It can make its skin whitish to blend in with the sandy bottom of the ocean floor and hide from predators or ambush prey. Or it can take on a bright, contrasting pattern to look threatening or attract a mate.

The key to these makeovers are special pigment-containing cells called chromatophores, which, when activated by light, can spread their pigments out or bunch them up to change the skin's overall color or pattern.

The researchers took pieces of skin and retina from a single female hogfish caught off the Florida Keys and analyzed all of its gene readouts, or RNA transcripts, to see which genes were switched on in each tissue.

Previous studies of other color-changing animals including cuttlefish and octopuses suggest the same molecular pathway that detects light in eyes may have been co-opted to sense light in the skin.

But Schweikert and colleagues found that hogfish skin works differently. Almost none of the genes involved in light detection in the hogfish's eyes were activated in the skin. Instead, the data suggest that hogfish skin relies on an alternative molecular pathway to sense light, a chain reaction involving a molecule called cyclic AMP.

Just how the hogfish's "skin vision" supplements input from the eyes to monitor light in their surroundings and bring about a color change remains unclear, Schweikert said. Light-sensing skin could provide information about conditions beyond the animal's field of view, or outside the range of wavelengths that the eye can pick up.

Together with previous studies, "the results suggest that fish have found a new way to 'see' with their skin and change color quickly," Schweikert said.

Many women in science are raising concerns over the fact that parents with young children are often excluded from fully participating in academic conference activities.

Early-stage researchers in the sciences often try to attend face-to-face academic conferences to advance their career by communicating new discoveries, forming collaborations, meeting potential funding agencies and recruiting new students. As the primary caregivers to young children, these parent-researchers, particularly women, face hurdles to fully attend and participate in necessary conferences due to pregnancy, breastfeeding, and caretaking conundrum addressed by a Working Group of Mothers in Science.

With a young child herself, Chapman University assistant professor of biological sciences, Patricia C. Lopes, Ph.D., has experienced this predicament many times.

"It's a serious problem because it creates a culture of inequity for parents, with mothers generally experiencing greater disadvantages than fathers because of biological, prejudicial and often socially-driven childcare demands," Lopes said.

Research shows this "baby penalty" negatively affects the career mobility of women, but not of men. Women of color face even larger disadvantages. Lopes joined a group of women in science to tackle this problem, seeking to help research societies and conference organizers better accommodate mothers and families. They hope that once changes are made by those willing to take leadership roles, women will no longer be excluded from full participation and therefore creativity and productivity in the sciences as a whole will flourish.

Their recommendations include:

Supporting mothers' attendance by offering financial support for individually arranged childcare at smaller conferences or onsite childcare for larger conferences. This would allow for frequent check-ins from parents and support breastfeeding.

Redistribute the ways in which scientific society use their funds are used, or modestly increase registration and/or exhibitor fees to support on-site childcare.

Offer discounted registration to parents who can attend only a portion of the conference.

Offer grants to fund travel and housing for caregivers.

Include family-friendly policies, events, resources and day schedules in conference advertisement materials.

Offer early-registrant parents flexibility in selecting the day and time they give their presentation.

Allow parents to share their nursing requirements, such as a private nursing room with a sink, on conference registration forms in order to better anticipate needs.

List resources in forms that extend beyond nursing, such as access to filtered water and bottle warmers, as well as baby changing facilities in all restrooms.

The group contends that adoption of any recommended practices will "send a strong and positive message that organizations recognize the issues parent-researchers face and they are working to support an inclusive, family-friendly environment."

Creating enough nanovesicles to inexpensively serve as a drug delivery system may be as simple as putting the cells through a sieve, according to an international team of researchers who used mouse autologous -- their own -- immune cells to create large amounts of fillable nanovesicles to deliver drugs to tumors in mice.

Nanovesicles are tiny sacs released by cells that carry chemical messages between cells. These nanovesicles are natural delivery vehicle and useful in drug delivery for cancer treatment.

"Currently, natural nanovesicles can be harvested from cell culture supernatant (the fluid surrounding cultured cells) and they are fillable," said Yuan Wan, postdoctoral fellow in biomedical engineering, Penn State. "However, there are two problems using them for cancer treatment. There aren't enough nanovesicles produced in short timescales and they do not have targeting effect."

The researchers developed an approach and platform to create large amounts of fillable and targeted nanovesicles. They report their results in a recent issue of Cancer Research.

To create targeted nanovesicles, ligands -- perhaps short pieces of protein -- need to be attached to the nanovesicle wall so they can recognize tumor cells. The process for making targeted nanovesicles now requires using viruses to insert relevant DNA fragments into the genome of the donor cells and then collecting ligand-bearing nanovesicles released from the gene-modified cells.

Yuan, working with Si-Yang Zheng, associated professor of biomedical engineering, developed a simpler and faster method for attaching ligands. The researchers chemically graft the lipid-tagged ligands onto the cell membrane. They do this before they pass the cells through a sieve, which converts the cell membranes into millions of vesicles bearing ligands that can be filled with an appropriate drug to target the cancer.

"Pushing the cells through a filter is the engineered way to produce lots of nanovesicles," said Zheng.

The researchers used mouse autologous immune cells and created the ligand-targeted, fillable nanovesicles in the laboratory. They then infused these drug-loaded nanovesicles into the original mouse to treat tumors.

"This approach enables us to create nanovesicles with different ligands targeting different types of tumors in about 30 minutes to meet actual needs," said Zheng. "With this approach, we also can put different types of ligands on a nanovesicle. We could have one ligand that targets while another ligand says, 'don't eat me.'"

Zheng is referring to the body's propensity to clear materials that do not belong from the blood stream. If a nanovesicle has a ligand attached that suggests the vesicle is autologous, then the vesicle, and its drug payload, might remain in circulation longer, making it more successful in finding and killing the target cancer cells.

The researchers believe that a variety of other cells, including stem cells, T cells -- cells of the immune system -- and other cell types could be modified and used as donor cells for extrusion of nanovesicles.

BINGHAMTON, N.Y. - As social networking companies feel the heat to create a more socially responsible and positive experience for their millions of users, new research out of Binghamton University, State University of New York explores how the interaction of personality traits can impact the likelihood of developing an addiction to social networking.

"There has been plenty of research on how the interaction of certain personality traits affects addiction to things like alcohol and drugs," said Binghamton University School of Management assistant professor of information systems Isaac Vaghefi. "We wanted to apply a similar framework to social networking addiction."

Vaghefi, with the help of Hamed Qahri-Saremi of DePaul University, collected self-reported data from nearly 300 college-aged students, and found that three personality traits in particular - neuroticism, conscientiousness and agreeableness - were related to social network addiction.

These three personality traits are part of the five-factor personality model, a well-established framework used to theoretically understand the human personality. Researchers found that the two other traits in the model - extraversion and openness to experience - did not play much of a role in the likelihood of developing a social network addiction.

In addition to testing the effect the singular traits had, researchers tested how the traits interact with one another as they relate to social network addiction.

"It's a complex and complicated topic. You can't have a simplistic approach," said Vaghefi.

Neuroticism and conscientiousness

On their own, the personality traits of neuroticism and conscientiousness have direct negative and positive effects on the likelihood of developing a social network addiction.

Researchers found that neuroticism (the extent to which people experience negative emotions such as stress and anxiety) seemed to increase the likelihood of developing an addiction to social network sites.

On the other hand, higher amounts of conscientiousness (having impulse control and the drive to achieve specific goals) seemed to decrease the likelihood of developing a social network addiction.

But when tested together, they found that neuroticism seemed to moderate the effect of conscientiousness as it relates to social network addiction.

Because someone can simultaneously be highly neurotic and conscientious, researchers found that even if someone is able to practice self-discipline and regularly persists at achieving goals, the fact that they may also be a stressful and anxious person often overrides the perceived control they may have over social network use.

This moderation effect could cause a conscientious person to be more likely to develop an addiction to social networking sites.

Conscientiousness and agreeableness

Researchers found that agreeableness alone, the degree to which someone is friendly, empathetic and helpful, didn't have a significant effect on social network addiction - but this changes when combined with conscientiousness.

A combination of low levels of both agreeableness and conscientiousness (someone can be both generally unsympathetic and irresponsible) often are related to a higher likelihood of social network addiction - but, oddly enough, so are a combination of high levels of both agreeableness and conscientiousness.

Vaghefi said this unexpected finding could be explained from a "rational addiction" perspective, meaning some users are intentionally using more of a social network to maximize the perceived benefits of it.

For example, he said an agreeable and friendly person may be making a very conscientious decision to use social networks more in order to interact with their friends, as they make it a deliberate goal to flourish those relationships through the use of social networks.

This is unique because this addiction would not be a result of irrationality or a lack of impulse control, as is often associated with addiction. Rather, a person would be developing an addiction through a rational and well-meaning process.

Vaghefi hopes that based on this research, people will look at the "whole picture" when it comes to how personality traits impact social networking addiction.

"It's more of a holistic approach to discover what kind of people are more likely to develop an addiction," said Vaghefi. "Rather than just focusing on one personality trait, this allows you to look at an all-inclusive personality profile."

Scientists report the existence of 15 new planets -- including one 'super-Earth' that could harbor liquid water -- orbiting small, cool stars near our solar system. These stars, known as red dwarfs[1], are of enormous interest for studies of planetary formation and evolution.

A research team led by Teruyuki Hirano of Tokyo Institute of Technology's Department of Earth and Planetary Sciences has validated 15 exoplanets[2] orbiting red dwarf systems.

One of the brightest red dwarfs, K2-155 that is around 200 light years away from Earth, has three transiting super-Earths, which are slightly bigger than our own planet. Of those three super-Earths, the outermost planet, K2-155d, with a radius 1.6 times that of Earth, could be within the host star's habitable zone[3].

The findings, published in the form of two papers in The Astronomical Journal, are based on data from NASA Kepler spacecraft's second mission, K2, and follow-up observations using ground-based telescopes, including the Subaru Telescope in Hawaii and the Nordic Optical Telescope (NOT) in Spain.

The researchers found that K2-155d could potentially have liquid water on its surface based on three-dimensional global climate simulations (see Figure 1). Hirano expresses both excitement and restraint, as he says: "In our simulations, the atmosphere and the composition of the planet were assumed to be Earth-like, and there's no guarantee that this is the case."

A more precise estimate of the radius and temperature of the K2-155 star would be needed to conclude definitively whether K2-155d is habitable. Achieving such precision would require further studies, for example, using interferometric techniques.

A key outcome from the current studies was that planets orbiting red dwarfs may have remarkably similar characteristics to planets orbiting solar-type stars.

"It's important to note that the number of planets around red dwarfs is much smaller than the number around solar-type stars," says Hirano. "Red dwarf systems, especially coolest red dwarfs, are just beginning to be investigated, so they are very exciting targets for future exoplanet research."

For example, while the so-called radius gap[4] of planets around solar-type stars has been reported previously, this is the first time that researchers have shown a similar gap in planets around red dwarfs. (See Figure 2.) "This is a unique finding, and many theoretical astronomers are now investigating what causes this gap," says Hirano.

He adds that the most likely explanation for the lack of large planets in the proximity of host stars is photoevaporation, which can strip away the envelope of the planetary atmosphere.

The researchers also investigated the relationship between planet radius and metallicity[5] of the host star. "Large planets are only discovered around metal-rich stars," Hirano says, "and what we found was consistent with our predictions. The few planets with a radius about three times that of Earth were found orbiting the most metal-rich red dwarfs."

The studies were conducted as part of the KESPRINT collaboration, a group formed by the merger of KEST (Kepler Exoplanet Science Team) and ESPRINT (Equipo de Seguimiento de Planetas Rocosos Intepretando sus Transitos) in 2016.

With the planned launch of NASA's Transiting Exoplanet Survey Satellite (TESS) in April 2018, Hirano is hopeful that even more planets will be discovered. "TESS is expected to find many candidate planets around bright stars closer to Earth," he says. "This will greatly facilitate follow-up observations, including investigation of planetary atmospheres and determining the precise orbit of the planets."

A recent study published in Oxford Economic Papers indicates that university education has a dramatically positive effect on the development of non-cognitive skills like conscientiousness, extraversion and agreeableness, in addition to the expected intellectual benefits. The paper also shows that the impact of education on these skills is even more dramatic for students from lower socioeconomic backgrounds.

University education coincides with the transition from adolescence into young adulthood. The nature of this maturation process is toward increasing levels of agreeableness, conscientiousness, and emotional stability and decreasing levels of openness to experience and extraversion. University training may alter this maturation process: Theoretically, it could boost, weaken, or even reverse population trends in personality trait maturation.

University education may impact character skills development by providing students with exposure to new peer groups and extracurricular activities including sport, politics, and art. Because students from disadvantaged backgrounds are likely to be more affected by a change in peer groups through day-to-day interaction with academically inclined peers and academic groups, there may be a greater effect of university education on students from disadvantaged backgrounds.

To measure character skills researchers used five personality traits--openness to experience, conscientiousness, extraversion, agreeableness, and neuroticism--which are widely accepted as a meaningful construct for describing differences in character skills by psychologists. Some of these character skills- extraversion or openness to new experiences - are important for employers. Other character skills- like agreeableness - are related to preferences such as reciprocity and altruism, which are significant for personal health and wellbeing.

To identify the effect of university education, researchers followed the education and character skills trajectories of 575 adolescents over eight years using nationally-representative, longitudinal data from the Household, Income, and Labour Dynamics in Australia survey. The data provide measures of character skills before potential university entry, and follow up measures four and eight years later.

The results indicate that every additional year spent at university is associated with increases in extraversion and agreeableness for youth from low socioeconomic backgrounds.

The results show that university education has positive effects on extraversion, reversing a downward sloping population trend in outward orientation as people age. It also accelerates an upward-sloping population trend in agreeableness for students from low socioeconomic status, boosting agreeableness scores from the lowest levels observed at baseline to the highest levels at the eight-year follow up. This finding suggests that the causal mechanism is likely to operate through actual exposure to university life, rather than through academic course content. Such interpretation is strengthened by the observation that length of exposure to university life is positively associated with character development.

As yet, no empirical evidence has existed on the matter. This study provides a robust empirical look at the role that university education plays in skills development in adolescents. Australian universities contribute to building sociability (extraversion) and the tendency to cooperate (agreeableness).

In addition, university education is associated with higher levels of agreeableness for both male and female students from low socioeconomic backgrounds, who started from the lowest baseline scores in adolescence and experienced the steepest growth curve as they entered university. This implies that students from disadvantaged backgrounds catch up with their peers from more privileged backgrounds, thus reducing initial levels of inequality in agreeableness.

"We see quite clearly that students' personalities change when they go to university, said the paper's lead researcher," Sonja Kassenboehmer. "Universities provide an intensive new learning and social environment for adolescents, so it is not surprising that this experience could impact on students' personality. It is good news that universities not only seem to teach subject-specific skills, but also seem to succeed in shaping skills valued by employers and society."