Category: Science News

{Blinking prompts eye muscles to keep our vision in line.}

Every few seconds, our eyelids automatically shutter and our eyeballs roll back in their sockets. So why doesn’t blinking plunge us into intermittent darkness and light? New research led by the University of California, Berkeley, shows that the brain works extra hard to stabilize our vision despite our fluttering eyes.

Scientists at UC Berkeley, Nanyang Technological University in Singapore, Université Paris Descartes and Dartmouth College have found that blinking does more than lubricate dry eyes and protect them from irritants. In a study published in today’s online edition of the journal Current Biology, they found that when we blink, our brain repositions our eyeballs so we can stay focused on what we’re viewing.

When our eyeballs roll back in their sockets during a blink, they don’t always return to the same spot when we reopen our eyes. This misalignment prompts the brain to activate the eye muscles to realign our vision, said study lead author Gerrit Maus, an assistant professor of psychology at Nanyang Technological University in Singapore. He launched the study as a postdoctoral fellow in UC Berkeley’s Whitney Laboratory for Perception and Action.

“Our eye muscles are quite sluggish and imprecise, so the brain needs to constantly adapt its motor signals to make sure our eyes are pointing where they’re supposed to,” Maus said. “Our findings suggest that the brain gauges the difference in what we see before and after a blink, and commands the eye muscles to make the needed corrections.”

From a big-picture perspective, if we didn’t possess this powerful oculomotor mechanism, particularly when blinking, our surroundings would appear shadowy, erratic and jittery, researchers said.

“We perceive coherence and not transient blindness because the brain connects the dots for us,” said study co-author David Whitney, a psychology professor at UC Berkeley.

“Our brains do a lot of prediction to compensate for how we move around in the world,” said co-author Patrick Cavanagh, a professor of psychological and brain sciences at Dartmouth College. “It’s like a steadicam of the mind.”

A dozen healthy young adults participated in what Maus jokingly called “the most boring experiment ever.” Study participants sat in a dark room for long periods staring at a dot on a screen while infrared cameras tracked their eye movements and eye blinks in real time.

Every time they blinked, the dot was moved one centimeter to the right. While participants failed to notice the subtle shift, the brain’s oculomotor system registered the movement and learned to reposition the line of vision squarely on the dot.

After 30 or so blink-synchronized dot movements, participants’ eyes adjusted during each blink and shifted automatically to the spot where they predicted the dot to be.

“Even though participants did not consciously register that the dot had moved, their brains did, and adjusted with the corrective eye movement,” Maus said. “These findings add to our understanding of how the brain constantly adapts to changes, commanding our muscles to correct for errors in our bodies’ own hardware.”

In addition to Maus, Whitney and Cavanagh, co-authors of the study are Marianne Duyck, Matteo Lisi and Therese Collins of the Université Paris Descartes.

{In reading tests at school, girls tend to be ahead of boys, in all age groups and in all countries. But in young adults, there is suddenly no longer any difference between men’s and women’s reading skills. Why is that? Could the answer be in the way the tests are designed?}

Girls are often said to be better at reading than boys. At least, that is what international reading studies like PIRLS and PISA show. The differences are clear in Norway, in the other Nordic countries, and right across the OECD. The gap is apparent amongst the 10 year olds measured in PIRLS, and it is even wider in the group of 15 year olds who take part in PISA.

The reading tests measure whether the pupils can extract information from the text, whether they can draw simple conclusions, interpret and compare information, and assess language, content and literary devices in the text. And regardless of which of these aspects is being measured, girls perform best.

The differences disappear in adults

But something happens when we measure the reading skills of adults. When the reading skills of 16-24 year olds are tested, the gender differences have suddenly become imperceptibly small — or have disappeared altogether. This has been shown in studies including the major PIAAC study, which tests adults’ skills in literacy, numeracy and ICT.

And while being able to read well is an important factor in enabling participation in education, work and society, there are no major gender differences in the Nordic region in these areas — which we might expect, if girls leave school with better skills than boys in reading, which is a fundamental skill. Although more women than men gain higher secondary or tertiary qualification, women are not ahead of men with regard to employment rate, participation in society or income — it is actually the reverse. Norwegian men are more likely to hold managerial positions than women, they are more involved in local politics, and Norwegian men earn more than Norwegian women.

Several hypotheses

Several hypotheses have already been put forward to explain why girls’ reading skills appear to be better than boys’ at school age. A difference in intelligence has been rejected, since girls obviously do not have higher IQ than boys. The same goes for the theory that the difference could have something to do with specific teaching methods, since reading is taught using a variety of methods. Some researchers claim that girls are subject to different requirements and expectations than boys, and that this could explain why girls appear to be better at reading. However, if this is the case, it cannot fully explain the differences. And we still do not have the answer to why this difference seems to disappear when the pupils leave secondary school and move into adult life.

Is the answer in the tests?

Literacy researchers Oddny Judith Solheim and Kjersti Lundetræ of the Norwegian Reading Centre, University of Stavanger have investigated whether the design of the tests themselves can provide at least a partial explanation as to why the differences that become more pronounced as children progress through school, then disappear in 16-24 year olds. The researchers studied the PIRLS (5th grade), PISA (10th grade) and PIAAC (adults) tests. They compared the tests in terms of the way they are designed, the way in which they measure reading, and the manner in which they are implemented.

All the tests apply the same definition of ‘reading literacy’: It is about being able to understand and use written text, and PISA and PIAAC also assess the ability to reflect on and evaluate texts.

To obtain a sufficiently extensive picture, the researchers at the Norwegian Reading Centre have examined the results of schoolchildren and adults in all of the Nordic countries. These countries are very similar, and have a high level of equality. But with a few exceptions, the gender differences in tests that measure reading tend to be equally great in Denmark, Finland, Sweden and Norway. The differences are apparent by the 5th grade, are greatest among 15 year olds, but then become imperceptibly small or completely absent in 16-24 year olds.

“Based on earlier research, it appears that PIRLS and PISA — i.e. the tests used in schools — are designed in a way that may favour girls. PIAAC is designed differently. This could be one explanation as to why we are seeing gender differences in the results,” says Solheim.

Continuous texts in the school tests

One of the characteristics of PISA and PIRLS is that these tests contain numerous ‘continuous texts’. This means long texts, which may be descriptive, narrative, explanatory, etc. Previous research has shown that girls and women are generally better at reading such texts than boys and men. Boys and men are better at reading ‘non-continuous texts’, such as graphs, forms, advertisements, etc. A number of studies also show that the differences are greater in favour of girls when pupils have to read fictional texts, than when they read factual texts.

In PIRLS, i.e. the tests for 10 year olds, the vast majority of texts are continuous, and the distribution of fictional texts and factual texts is the same. In PISA, 60 per cent of the texts are continuous, and 15 per cent of the texts are fictional. However in PIAAC, there are equal numbers of continuous texts as non-continuous texts, and the participants only have to read factual texts.

“Since we know that it is an advantage for girls to read long, fictional texts, it could be giving them an advantage to provide them with this type of text in the reading tests, which could affect the results in terms of measuring pupils’ skills,” says Solheim.

Measuring reading through writing

Although there are no differences between young adult men and women when their reading skills are measured, several international studies show that girls and women are better at writing than boys and men. Some of the questions in PISA and PIRLS are multiple-choice, where pupils must select what they believe to be the correct answer. However, in recent years, more of the questions have been open-ended, requiring the pupils to provide a written answer. It is believed that this achieves a better picture of what the pupils have understood from the text, and how they reflect on it and assess it. Reading is then being measured through writing — which gives girls an advantage. In PISA, where the difference between girls and boys is greatest, 65 per cent of the exercises involve writing. In PIAAC, on the other hand, the participants do not need to write, and instead have to select words, sentences or extracts from the texts.

Several studies have shown that the gender differences are greater in written exercises than in multiple-choice questions, and that boys have a greater tendency to skip the written questions. For this reason, the two literacy researchers believe that we may say that in this aspect too, PISA and PIRLS are more girl-friendly than PIAAC.

Motivation

Motivation is an important element when we look at how reading skills are measured in these tests. Motivation to do one’s best, to read the texts thoroughly, and actually to take the trouble to answer difficult written exercises. Differences in motivation to do the tests could explain a great deal of why girls appear to read better than boys at school, but not when they reach adulthood.

For example, earlier research shows that it is more difficult to motivate boys to be interested in a text than girls. The gender of the protagonist, the subject of the text and attitudes to the text or general subject play more of a role for boys in how well they perform when they have to read than for girls. For this reason, the researchers at the Norwegian Reading Centre believe that the test designers should take into account boys’ motivation to read the texts they are given in the tests.

We also know that girls are more likely to do what is expected of them than boys. Boys are more likely to ask whether there is a point to what they have been asked to do, such as a test. We see the biggest differences in the tests that are performed in the 10th grade. This is a period during which pupils are facing many other challenges from their school.

“Since we know that boys are more critical about doing things that have no direct significance for them, it is conceivable that they are more likely to avoid expending energy on a test that will not affect their qualifications. Motivation could also explain part of the reason why the differences are greater at lower secondary school than primary school, since it is well known that teenagers are more likely to question authority, such as the school, than younger children,” says Solheim.

While the pupils performed the tests at school, the adult participants in PIAAC were invited to do the test in their own home, supervised by a PIAAC representative. The participants in PIAAC were also rewarded for their contribution once they had completed the test.

The researchers suggest that when a person comes home to you and stays with you while you answer questionnaires and sit tests, and is offered an incentive to participate, it is reasonable to assume that you might feel more obligated to do your best, than someone sitting in a classroom who will not receive any particular reward for doing the test as well as they can. Is it therefore conceivable that the boys and men who underwent PIAAC were more likely to show the full extent of their reading ability, than the boys who took part in PISA.

Reason to be concerned?

The difference in reading between girls and boys has been highlighted as an educational challenge in most OECD countries, including Norway. Lundetræ and Solheim believe that their findings must be taken into consideration in the design of tests aimed at measuring reading skills, and in the interpretation of the results of these reading studies.

“Reading is described as a skill, which we have the potential to achieve. We may question whether the various tests, in their current design, give boys and girls, and men and women, an equal basis for achieving their potential as readers. We now know that reading tests in schools are designed in a way that affects girls positively. We also have to question whether PIAAC reflects men’s reading skills more accurately than PIRLS and PISA, or whether the adult tests may be giving the men an advantage. This means that the challenge now is to find out how we can create reading tests that accurately demonstrate the actual skills of all boys and girls, and men and women, in terms of reading. That would give us a better basis for saying whether there really is reason to be concerned about boys’ reading skills,” says Solheim.

{Harvard University and Boston Children’s Hospital researchers have developed a customizable soft robot that fits around a heart and helps it beat, potentially opening new treatment options for people suffering from heart failure.}

The soft robotic sleeve twists and compresses in synch with a beating heart, augmenting cardiovascular functions weakened by heart failure. Unlike currently available devices that assist heart function, Harvard’s soft robotic sleeve does not directly contact blood. This reduces the risk of clotting and eliminates the need for a patient to take potentially dangerous blood thinner medications. The device may one day be able to bridge a patient to transplant or to aid in cardiac rehabilitation and recovery.

“This research demonstrates that the growing field of soft robotics can be applied to clinical needs and potentially reduce the burden of heart disease and improve the quality of life for patients,” said Ellen T. Roche, the paper’s first author and former PhD student at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and The Wyss Institute of Biologically Inspired Engineering at Harvard University. Roche is currently a postdoctoral fellow at the National University of Ireland.

The research, published in Science Translational Medicine, was a collaboration between SEAS, the Wyss Institute and Boston Children’s Hospital.

“This work represents an exciting proof of concept result for this soft robot, demonstrating that it can safely interact with soft tissue and lead to improvements in cardiac function. We envision many other future applications where such devices can delivery mechanotherapy both inside and outside of the body,” said Conor Walsh, senior author of the paper and the John L. Loeb Associate Professor of Engineering and Applied Sciences at SEAS and Core Faculty Member at the Wyss Institute.

Heart failure affects 41 million people worldwide. Today, some of the options to treat it are mechanical pumps called ventricular assist devices (VADs), which pump blood from the ventricles into the aorta, and heart transplant. While VADs are continuously improving, patients are still at high risk for blood clots and stroke.

To create an entirely new device that doesn’t come into contact with blood, Harvard researchers took inspiration from the heart itself. The thin silicone sleeve uses soft pneumatic actuators placed around the heart to mimic the outer muscle layers of the mammalian heart. The actuators twist and compress the sleeve in a similar motion to the beating heart.

The device is tethered to an external pump, which uses air to power the soft actuators.

The sleeve can be customized for each patient, said Roche. If a patient has more weakness on the left side of the heart, for example, the actuators can be tuned to give more assistance on that side. The pressure of the actuators can also increase or decrease over time, as the patient’s condition evolves.

The sleeve is attached to the heart using a combination of a suction device, sutures and a gel interface to help with friction between the device and the heart.

The SEAS and Wyss engineers worked with surgeons at Boston Children’s Hospital to develop the device and determine the best ways to implant the device and test it on animal models.

“The cardiac field had turned away from idea of developing heart compression instead of blood-pumping VADs due to technological limitations, but now with advancements in soft robotics it’s time to turn back,” said Frank Pigula, a cardiothoracic surgeon and co-corresponding author on the study, who was formerly clinical director of pediatric cardiac surgery at Boston Children’s Hospital and is now a faculty member at University of Louisville and division chief of pediatric cardiac surgery at Kosair Children’s Hospital. “Most people with heart failure do still have some function left; one day the robotic sleeve may help their heart work well enough that their quality of life can be restored.”

More research needs to be done before the sleeve can be implanted in humans but the research is an important first step towards an implantable soft robot that can augment organ function.

“This research is really significant at the moment because more and more people are surviving heart attacks and ending up with heart failure,” said Roche. “Soft robotic devices are ideally suited to interact with soft tissue and give assistance that can help with augmentation of function, and potentially even healing and recovery.”

{How different are men and women’s brains?}

The latest evidence to address this controversy comes from a study at Rosalind Franklin University of Medicine and Science, where a meta-analysis of human amygdala volumes found no significant difference between the sexes. Meta-analysis is a statistical approach for combining the results of multiple studies, in this case dozens of brain MRI studies.

“Despite the common impression that men and women are profoundly different, large analyses of brain measures are finding far more similarity than difference,” said Lise Eliot, PhD, principal investigator and associate professor of neuroscience at RFU’s Chicago Medical School. “There is no categorically ‘male brain’ or ‘female brain,’ and much more overlap than difference between genders for nearly all brain measures.”

The olive-sized amygdala is a key brain structure involved in all types of emotion and in social behaviors such as aggression and sexual arousal. Animal studies and early MRI reports indicated that the amygdala is disproportionately larger in males’ brains. Such a size difference has been suggested to contribute to sex differences in emotionality and in the prevalence of disorders such as anxiety and depression.

Biologists use the term “sexually dimorphic” (literally, “two different forms”) to describe male-female differences. This new study shows that the term does not apply to human amygdala volume. It joins other recent research that challenges the concept of binary “male” and “female” human brains, and may have relevance to understanding disorders including depression, substance abuse, and gender dysphoria.

The report is co-authored by RFU medical students Dhruv Marwha and Meha Halari, who worked with Eliot to systematically identify all MRI studies of the human amygdala over the past 30 years. They found 58 published comparisons of amygdala volume in matched groups of healthy men and women (or boys and girls). Studies reporting raw amygdala volume show that the structure is indeed about 10 percent larger in male brains. However, this difference is comparable to males’ larger body size, including the 11-12 percent larger volume of males’ brains overall. Among studies that reported amygdala volumes corrected for overall brain size, the volume difference was negligible (<0.1 percent in the right amygdala, 2.5 percent in the left amygdala) and not statistically significant. The paper appears in the journal NeuroImage. In a similar 2015 meta-analysis, Dr. Eliot headed a Chicago Medical School team that debunked the widely-held belief that the brain's hippocampus, which consolidates new memories, is larger in women than men. "There are behavioral reasons to suspect a sex difference in the amygdala," Dr. Eliot said. "Emotion, empathy, aggression, and sexual arousal all depend on it. Also, the evidence from animal studies suggesting a sex difference in amygdala volume is stronger than it is for the hippocampus. So this finding is more surprising than our hippocampal result and suggests that human brains are not as sexually dimorphic as rats." This study strengthens the case for gender similarity in the human brain and psychological abilities and has implications for efforts to understand the transgender brain.

{1 in 5 young people regularly wake up in the night to send or check messages on social media, according to new research published today in the Journal of Youth Studies. This night-time activity is making teenagers three times more likely to feel constantly tired at school than their peers who do not log on at night, and could be affecting their happiness and wellbeing.}

Over 900 pupils, aged between 12-15 years, were recruited and asked to complete a questionnaire about how often they woke up at night to use social media and times of going to bed and waking. They were also asked about how happy they were with various aspects of their life including school life, friendships and appearance.

1 in 5 reported ‘almost always’ waking up to log on, with girls much more likely to access their social media accounts during the night than boys. Those who woke up to use social media nearly every night, or who didn’t wake up at a regular time in the morning, were around three times as likely to say they were constantly tired at school compared to their peers who never log on at night or wake up at the same time every day. Moreover, pupils who said they were always tired at school were, on average, significantly less happy than other young people.

“Our research shows that a small but significant number of children and young people say that they often go to school feeling tired — and these are the same young people who also have the lowest levels of wellbeing. One in five young people questioned woke up every night and over one third wake-up at least once a week to check for messages. Use of social media appears to be invading the ‘sanctuary’ of the bedroom.” Said author Professor Sally Power, Co-Director (Cardiff) Wales Institute for Social & Economic Research, Data & Methods (WISERD).

The study findings support growing concerns about young people’s night-time use of social media. However, because of the complex range of possible explanations for tiredness at school, further larger studies will be needed before any firm conclusions can be made about the social causes and consequences of sleep deprivation among today’s youth.

{The timing of the first entry of humans into North America across the Bering Strait has now been set back 10,000 years.}

This has been demonstrated beyond a shadow of a doubt by Ariane Burke, a professor in Université de Montréal’s Department of Anthropology, and her doctoral student Lauriane Bourgeon, with the contribution of Dr. Thomas Higham, Deputy Director of Oxford University’s Radiocarbon Accelerator Unit.

The earliest settlement date of North America, until now estimated at 14,000 years Before Present (BP) according to the earliest dated archaeological sites, is now estimated at 24,000 BP, at the height of the last ice age or Last Glacial Maximum.

The researchers made their discovery using artifacts from the Bluefish Caves, located on the banks of the Bluefish River in northern Yukon near the Alaska border. The site was excavated by archaeologist Jacques Cinq-Mars between 1977 and 1987. Based on radiocarbon dating of animal bones, the researcher made the bold hypothesis that human settlement in the region dated as far back as 30,000 BP.

In the absence of other sites of similar age, Cinq-Mars’ hypothesis remained highly controversial in the scientific community. Moreover, there was no evidence that the presence of horse, mammoth, bison and caribou bones in the Bluefish Caves was due to human activity.

To set the record straight, Bourgeon examined the approximate 36,000 bone fragments culled from the site and preserved at the Canadian Museum of History in Gatineau — an enormous undertaking that took her two years to complete. Comprehensive analysis of certain pieces at UdeM’s Ecomorphology and Paleoanthropology Laboratory revealed undeniable traces of human activity in 15 bones. Around 20 other fragments also showed probable traces of the same type of activity.

“Series of straight, V-shaped lines on the surface of the bones were made by stone tools used to skin animals,” said Burke. “These are indisputable cut-marks created by humans.”

Bourgeon submitted the bones to further radiocarbon dating. The oldest fragment, a horse mandible showing the marks of a stone tool apparently used to remove the tongue, was radiocarbon-dated at 19,650 years, which is equivalent to between 23,000 and 24,000 cal BP (calibrated years Before Present).

“Our discovery confirms previous analyses and demonstrates that this is the earliest known site of human settlement in Canada,” said Burke. It shows that Eastern Beringia was inhabited during the last ice age.”

Beringia is a vast region stretching from the Mackenzie River in the Northwest Territories to the Lena River in Russia. According to Burke, studies in population genetics have shown that a group of a few thousand individuals lived in isolation from the rest of the world in Beringia 15,000 to 24,000 years ago.

“Our discovery confirms the ‘Beringian standstill [or genetic isolation] hypothesis,’” she said, “Genetic isolation would have corresponded to geographical isolation. During the Last Glacial Maximum, Beringia was isolated from the rest of North America by glaciers and steppes too inhospitable for human occupation to the West. It was potentially a place of refuge.”

The Beringians of Bluefish Caves were therefore among the ancestors of people who, at the end of the last ice age, colonized the entire continent along the coast to South America.

The results of Lauriane Bourgeon’s doctoral research were published in the January 6 edition of PLoS One under the title “Earliest Human Presence in North America Dated to the Last Glacial Maximum: New Radiocarbon Dates from Bluefish Caves, Canada.” The article is co-authored by Professor Burke and by Dr. Thomas Higham of Oxford University’s Radiocarbon Accelerator Unit, in the U.K.

{As humans, we constantly strive for a good work-life balance. New findings by researchers at Missouri University of Science and Technology suggest that ants, long perceived as the workaholics of the insect world, do the same. In fact, according to these researchers, it is imperative that some ants rest while others work to conserve food, energy and resources for the colony. And the larger the colony, the more important this work-rest balance becomes.}

“It has been a long-standing question in the field as to why large colonies of ants use less per-capita energy than small colonies,” says Dr. Chen Hou, assistant professor of biological sciences at Missouri S&T and research team lead. “In this work, we found that this is because in large colonies, there are relatively more ‘lazy workers,’ who don’t move around, and therefore don’t consume energy.

“We found that the portion of inactive members of a group increases in a regular pattern with the group size,” Hou says.

The research team consistently observed that 60 percent of workers were not moving around in a 30-ant group, whereas this percentage increased to 80 percent when the group size increased to 300 ants.

“The simultaneous energetic measurements showed that the per capita energy consumption in the 300-ant group is only 50 percent of that in the 30-ant group,” Hou says.

By not consuming energy, these “lazy” ants are actually saving resources for the colony and making the colony more productive.

This realization could provide valuable insight into making our societies more productive and sustainable.

“Humans are like ants in a way that we all live together in groups, collaborating toward our own betterment,” Hou says. “Both humans and ants face similar problems of allocating resources based on tasks and energy. Understanding how ants spend their energy in relation to their group and why they do so will provide insight into conditions for individuals that allow a group to perform collective optimization of behavior, that is, in the context of sustainable use of scarce resources.”

Hou and his team, which includes two undergraduate Missouri S&T students, discuss their findings in a forthcoming issue of the journal Insect Science.

“Maximizing resource acquisition would require most individuals to be highly active, but would also result in high energy expenditure and long average foraging time. In contrast, minimizing time and energy expenditure would require most individuals to be inactive, but would also result in low resource acquisition,” Hou says. “Thus, we postulate that ant colonies balance these two optimization rules by the coordination of the forager’s interaction.”

Hou says his team came to its conclusion using a state-of-the-art computerized vision analysis program to track the motion trajectories of ants. His colleague, Dr. Zhaozheng Yin, assistant professor and Daniel C. St. Clair Fellow of computer science at Missouri S&T, developed the program.

Using Yin’s automatic algorithm, the research team was able to analyze the movements of ants over longer periods of time and higher temporal resolution than had ever previously been conducted. Previous studies had only analyzed the movements of ants in minute-long intervals. The analysis of a two-hour-long video by the research team showed a large variation in the average walking speed of ants in the colony, from .2 centimeters a second to 1.4 centimeters a second.

“This indicates it is likely that the analyses of one-minute observations give only momentary snapshots, and may not well represent the ants’ behaviors over long periods,” says Hou. “These comparisons highlight the advantage of our automatic computerized tracking technique, because it is difficult, if not possible, to manually digitize coordinates of individual ants with high temporal resolution over a long period.”

By tracking ants’ walking behaviors over longer periods of time, the researchers also determined how much energy ants consume while working as opposed to resting.

“We found that walking ants consume five times more energy than resting ants,” says Hou. “This means that energy wise, one walking ant is equivalent to five resting ants. Thus, if a group has 20 percent active members, this group would consume 180 percent more energy than a similar sized group with all inactive members.”

The research team, which also includes sophomore Nolan Ferral and junior Kyara Holloway, both biological sciences majors at Missouri S&T, and Mingzhong Li, a Ph.D. student in computer science, shared its findings in an article titled “Heterogeneous activity causes a nonlinear increase in the group energy use of ant workers isolated from queen and brood.” The article will be published in an upcoming issue of Insect Science.

“It is intuitive that colonies have inactive members, because these members may serve a backup role or buffer, which would be activated when colonies are under stress, such as an urgent need for nest maintenance or defense,” says Hou. “But it is unclear why the proportion of the inactive members is not a constant — why larger colonies have relatively more ‘lazy’ workers. Thus, our study calls for future research on ant interaction networking and behaviors.”

{41% of Americans make New Year’s resolutions but only 9% feel they were successful in keeping their resolutions. The problem may be in the timing. According to research being presented at the Society for Personality and Social Psychology (SPSP) Annual Convention the time for successful habit change isn’t based on the calendar, but on big changes to our everyday lives like moving to a new home.}

“Changing your habits is very difficult,” says Bas Verplanken, professor of social psychology at the University of Bath, “including finding the right moment to make a change.”

{{Everyday choices}}

Habits develop when we repeat behaviors, and they are reinforced the more everything around us stays the same. Some habits are beneficial, such as brushing your teeth daily. Other habits can benefit communities and affect how we respond to decisions such as recycling, what we buy, and how we commute.

Work from Verplanken and colleagues show habits can be changed when you change the factors around the habit (location, context). Researchers call this the “discontinuity effect.”

{{Why New Year’s resolutions don’t work}}

“Changing from December 31st to January 1st is not a dramatic discontinuity,” says Verplanken. “Many resolutions are made on December 31st, and go down the drain on January 2nd.”

Verplanken notes the New Year may be a nice moment to mark the start of a new phase, but the point of the discontinuity effect is that the change in behavior is embedded in other changes.

“In the case of moving to a new home for instance, people may need to find new solutions for how to do things in the new house, where and how to shop, commute, and so on. All of these aspects are absent when talking about New Year resolutions.”

{{Location matters}}

Verplanken studied the behaviors of over 800 people, half of whom had recently moved and half of whom had been at the same home for several years. Participants responded to questions on 25 environment related behaviors including water and energy use, commuting choices, and waste (food waste, recycling).

According to his research, people who received an intervention and had recently relocated reported more change eight weeks later on a composite of twenty-five environment-relevant behaviors compared to participants who had not recently relocated.

These results were consistent in spite of the strength of previous habits and views, and are consistent with research from others.

Verplanken will present his talk, Empowering Interventions to Promote Sustainable Lifestyles: Testing the Habit Discontinuity Hypothesis in a Field Experiment on January 20, 2017 at the SPSP Annual Convention.

{Schools should use both ability grouping and acceleration to help academically talented students, reports a new Northwestern University study that examined a century of research looking at the controversial subject.}

Ability grouping places students of similar skills and abilities in the same classes. Acceleration, most commonly known as grade skipping, subject acceleration or early admission into kindergarten or college, gives students the chance to access opportunities earlier or progress more rapidly.

The widely debated educational techniques effectively increase academic achievement at a low cost and can benefit millions of students in U.S. school systems, according to the study, published in Review of Educational Research.

“Although acceleration is widely supported by research as an effective strategy for meeting the needs of advanced learners, it’s still rarely used, and most schools do not systematically look for students who need it,” said study co-author Paula Olszewski-Kubilius, director of the Center for Talent Development at the Northwestern’s School of Education and Social Policy.

The U.S. spends nearly $600 billion a year on public education, but research questions whether the resources are reaching high-performing students. A recent policy brief reported that 20 to 40 percent of elementary and middle school students perform above grade level in reading and 10 to 30 percent do so in math, according to the study.

Proponents of ability and acceleration point to benefits for children who are under-challenged in their grade-level classroom. With a more homogenous learning environment, it’s easier for teachers to match their instruction to a student’s needs and the students benefit from interacting with comparable academic peers.

Critics argue that dividing the students can mean the loss of leaders or role models, greater achievement gaps and lower self-esteem for struggling students.

But the research indicated that students benefited from within-class grouping, cross-grade subject grouping and gifted and talented programs, although the benefits were negligible for between class groupings.

Accelerated students performed significantly better than non-accelerated same-age peers, and comparable to non-accelerated older students, according to the study.

Others have said education should “avoid trying to teach students what they already know,” the authors wrote. “Based on the nearly century’s worth of research, we believe the data clearly suggest that ability grouping and acceleration are two such strategies for achieving this goal.”

Though hardly the final word on such a hot-button issue, the new study helps clarify the academic effects of ability grouping and acceleration.

“The conversation needs to evolve beyond whether such interventions can ever work,” they wrote. The bulk of evidence over the last century “suggests that academic acceleration and most forms of ability grouping like cross-grade subject grouping and special grouping for gifted students can greatly improve K-12 students’ academic achievement.”

Northwestern’s Saiying Steenbergen-Hu of the Center for Talent Development was the lead author of the report, which was also co-authored by Matthew Makel of Duke University’s Talent Identification Program. The authors reviewed 172 empirical studies on the efficacy of ability grouping as well as 125 studies on acceleration.

{A UC San Francisco-led study has identified signatures of ethnicity in the genome that appear to reflect an ethnic group’s shared culture and environment, rather than their common genetic ancestry.}

The study examined DNA methylation — an “annotation” of DNA that alters gene expression without changing the genomic sequence itself — in a group of diverse Latino children. Methylation is one type of “epigenetic mark” that previous research has shown can be either inherited or altered by life experience. The researchers identified several hundred differences in methylation associated with either Mexican or Puerto Rican ethnicity, but discovered that only three-quarters of the epigenetic difference between the two ethnic subgroups could be accounted for by differences in the children’s genetic ancestry. The rest of the epigenetic differences, the authors suggest, may reflect a biological stamp made by the different experiences, practices, and environmental exposures distinct to the two ethnic subgroups.

The discovery could help scientists understand how social, cultural, and environmental factors interact with genetics to create differences in health outcomes between different ethnic populations, the authors say, and provides a counterpoint to long-standing efforts in the biomedical research community to replace imprecise racial and ethnic categorization with genetic tests to determine ancestry.

“These data suggest that the interplay between race and ethnicity as social constructs and genetic ancestry as a biological construct is more complex than we had realized,” said Noah Zaitlen, PhD, a UCSF assistant professor of medicine and co-senior author on the new study. “In a medical context both elements may provide valuable information.”

The research — published January 3, 2017 in the online journal eLife — was led by Joshua Galanter, MD, MAS, formerly an assistant professor of medicine, of bioengineering and therapeutic sciences, and of epidemiology and biostatistics at UCSF, who is now a scientist at Genentech. The research was jointly supervised by Zaitlen and co-senior author Esteban Burchard, MD, MPH, a professor of bioengineering and therapeutic sciences and of medicine in UCSF’s schools of Pharmacy and Medicine and the Harry Wm. and Diana V. Hind Distinguished Professorship in Pharmaceutical Sciences II at UCSF.

“This is a big advancement of our understanding of race and ethnicity,” Burchard said. “There’s this whole debate about whether race is fundamentally genetic or is just a social construct. To our knowledge this is the first time anyone has attempted to quantify the molecular signature of the non-genetic components of race and ethnicity. It demonstrates in a whole new way that race combines both genetics and environment.”

Teasing apart roles of genetics, environment in ethnic differences in disease

Researchers and clinicians have known for many years that different racial and ethnic populations get diseases at different rates, respond differently to medications, and show very different results on standard clinical tests: “For a whole range of medical tests, whether your physician is told that your lab result is normal or abnormal depends entirely on the race/ethnicity box that you tick on an intake form,” Zaitlen said.

It’s tempting to assume that such health disparities between races and ethnicities all stem from inherited genetic differences, but that’s not necessarily the case. Different racial and ethnic groups also eat different diets, live in neighborhoods with more or less pollution, experience different levels of poverty, and are more or less likely to smoke tobacco, all of which could also impact their health outcomes.

“A lot of our research involves trying to tease apart how much of health differences between populations are genetic and how much are environmental,” Zaitlen said.

The researchers turned to epigenetics to search for answers to these questions because these molecular annotations of the genetic code have a unique position between genetic ancestry and environmental influence. Unlike the rest of the genome, which is only inherited from an individual’s parents (with random mutations here and there), methylation and other epigenetic annotations can be modified based on experience. These modifications influence when and where particular genes are expressed and appear to have significant impacts on disease risk, suggesting explanations for how environmental factors such as maternal smoking during pregnancy can influence a child’s risk of later health problems.

Epigenetic signatures of ethnicity could be biomarkers for shared cultural experiences

In the new study, the team examined methylation signatures in 573 children of self-identified Mexican or Puerto-Rican identity drawn from the GALA II study, a cohort previously developed by Burchard to study environmental and genetic components of asthma risk in Latino children. They identified 916 methylation sites that varied with ethnic identity, but found that only 520 of these differences could be completely explained by genetic ancestry — 109 could be partially explained by ancestry, while 205 could not be explained by ancestry at all.

Overall, the researchers found that about 76 percent of the effect of ethnicity on DNA methylation could be accounted for by controlling for genetic ancestry, suggesting that nearly a quarter of the effect must be due to other, unknown factors. The researchers found that many of these additional methylation sites corresponded to sites that previous studies had shown to be sensitive to environmental and social factors such as maternal smoking, exposure to diesel exhaust, and psychosocial stress. This led the team to hypothesize that a large fraction of their newly disovered epigenetic markers of ethnicity likely reflect biological signatures of environmental, social, or cultural differences between ethnic subgroups.

“This suggests that using epigenetics as a biomarker could give you a lot of information about environmental exposures within particular populations that’s not captured by genetics,” Zaitlen said. “Our next step will be to understand how specific epigenetic signatures are linked to particular environmental exposures, and use those signals to understand patient risk.”

Scientists and clinicians have increasingly tried to move away from simplistic racial and ethnic categories in disease research, the authors say, and — with the rise of precision medicine — in clinical diagnosis and treatment as well. Studies by the Burchard group and others have found that using genetic ancestry rather than ethnic self-identification significantly improves diagnostic accuracy for certain diseases.

But the new data showing that a large fraction of epigenetic signatures of ethnicity reflect something other than ancestry suggests that abandoning the idea of race and ethnicity altogether could sacrifice a lot of valuable information about the drivers of differences in health and disease between different communities.

“Like a standard family history, ethnicity is association with disease for both genetic and environmental reasons,” Zaitlen said. “If your dad or mom had a heart attack, that tells doctors a lot about your risk for a heart attack. Part of that is genetic, but part of it is that your lifestyle is influenced heavily by your parents’ lifestyle. Your ethnic group is like a much bigger family — it’s partly a matter of genetics, but it also reflects the environment of your broader community.”