Galaxies more than 1 million light-years apart should have completely independent lives in terms of when they give birth to new stars. But galaxies separated by up to 13 million light-years slowed down and then simultaneously accelerated their birth rate of stars, according to a Rutgers-led study published in the Astrophysical Journal.

“It appears that these galaxies are responding to a large-scale change in their environment in the same way a good economy can spur a baby boom,” said lead author Charlotte Olsen, a doctoral student in the Department of Physics and Astronomy in the School of Arts and Sciences at Rutgers University-New Brunswick.

“We found that regardless of whether these galaxies were next-door neighbors or not, they stopped and then started forming new stars at the same time, as if they’d all influenced each other through some extra-galactic social network,” said co-author Eric Gawiser, a professor in the Department of Physics and Astronomy.

The simultaneous decrease in the stellar birth rate in the 36 dwarf galaxies began 6 billion years ago, and the increase began 3 billion years ago. Understanding how galaxies evolve requires untangling the many processes that affect them over their lifetimes (billions of years). Star formation is one of the most fundamental processes. The stellar birth rate can increase when galaxies collide or interact, and galaxies can stop making new stars if the gas (mostly hydrogen) that makes stars is lost.

Star formation histories can paint a rich record of environmental conditions as a galaxy “grew up.” Dwarf galaxies are the most common but least massive type of galaxies in the universe, and they are especially sensitive to the effects of their surrounding environment.

The 36 dwarf galaxies included a diverse array of environments at distances as far as 13 million light-years from the Milky Way. The environmental change the galaxies apparently responded to must be something that distributes fuel for galaxies very far apart. That could mean encountering a huge cloud of gas, for example, or a phenomenon in the universe we don’t yet know about, according to Olsen.

The scientists used two methods to compare star formation histories. One uses light from individual stars within galaxies; the other uses the light of a whole galaxy, including a broad range of colors.

“The full impact of the discovery is not yet known as it remains to be seen how much our current models of galaxy growth need to be modified to understand this surprise,” Gawiser said. “If the result cannot be explained within our current understanding of cosmology, that would be a huge implication, but we have to give the theorists a chance to read our paper and respond with their own research advances.”

“The James Webb Space Telescope, scheduled to be launched by NASA this October, will be the ideal way to add that new data to find out just how far outwards from the Milky Way this ‘baby boom’ extended,” Olsen added.

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Many don’t even know they have the condition.

Only 1 in 10 people with diabetes in the 55 low- and middle-income countries studied receive the type of comprehensive care that’s been proven to reduce diabetes-related problems, according to the new findings published in Lancet Healthy Longevity.

That comprehensive package of care — low-cost medicines to reduce blood sugar, blood pressure and cholesterol levels; and counseling on diet, exercise and weight — can help lower the health risks of under-treated diabetes. Those risks include future heart attacks, strokes, nerve damage, blindness, amputations and other disabling or fatal conditions.

The new study, led by physicians at the University of Michigan and Brigham and Women’s Hospital with a global team of partners, draws on data from standardized household studies, to allow for apples-to-apples comparisons between countries and regions.

The authors analyzed data from surveys, examinations and tests of more than 680,000 people between the ages of 25 and 64 worldwide conducted in recent years. More than 37,000 of them had diabetes; more than half of them hadn’t been formally diagnosed yet, but had a key biomarker of elevated blood sugar.

The researchers have provided their findings to the World Health Organization, which is developing efforts to scale up delivery of evidence-based diabetes care globally as part of an initiative known as the Global Diabetes Compact. The forms of diabetes-related care used in the study are all included in the 2020 WHO Package of Essential Noncommunicable Disease Interventions.

“Diabetes continues to explode everywhere, in every country, and 80% of people with it live in these low- and middle-income countries,” says David Flood, M.D., M.Sc., lead author and a National Clinician Scholar at the U-M Institute for Healthcare Policy and Innovation. “It confers a high risk of complications such as including heart attacks, blindness, and strokes. We can prevent these complications with comprehensive diabetes treatment, and we need to make sure people around the world can access treatment.”

Flood worked with senior author Jennifer Manne-Goehler, M.D., Sc.D., of Brigham and Women’s Hospital and the Medical Practice Evaluation Center at Massachusetts General Hospital, to lead the analysis of detailed global data.

Key findings

In addition to the main finding that 90% of the people with diabetes studied weren’t getting access to all six components of effective diabetes care, the study also finds major gaps in specific care.

For instance, while about half of all people with diabetes were taking a drug to lower their blood sugar, and 41% were taking a drug to lower their blood pressure, only 6.3% were receiving cholesterol-lowering medications.

These findings show the need to scale-up proven treatment not only to lower glucose but also to address cardiovascular disease risk factors, such as hypertension and high cholesterol, in people with diabetes.

Less than a third had access to counseling on diet and exercise, which can help guide people with diabetes to adopt habits that can control their health risks further.

Even when the authors focused on the people who had already received a formal diagnosis of diabetes, they found that 85% were taking a medicine to lower blood sugar, 57% were taking a blood pressure medication, but only 9% were taking something to control their cholesterol. Nearly 74% had received diet-related counseling, and just under 66% had received exercise and weight counseling.

Taken together, less than one in five people with previously diagnosed diabetes were getting the full package of evidence-based care.

Relationship to national income and personal characteristics

In general, the study finds that people were less likely to get evidence-based diabetes care the lower the average income of the country and region they lived in. That’s based on a model that the authors created using economic and demographic data about the countries that were included in the study.

The nations in the Oceania region of the Pacific had the highest prevalence of diabetes — both diagnosed and undiagnosed — but the lowest rates of diabetes-related care.

But there were exceptions where low-income countries had higher-than-expected rates of good diabetes care, says Flood, citing the example of Costa Rica. And in general, the Latin America and Caribbean region was second only to Oceania in diabetes prevalence, but had much higher levels of care.

Focusing on what countries with outsize achievements in diabetes care are doing well could provide valuable insights for improving care elsewhere, the authors say. That even includes informing care in high-income countries like the United States, which does not consistently deliver evidence-based care to people with diabetes.

The study also shines a light on the variation between countries and regions in the percentage of cases of diabetes that have been diagnosed. Improve reliable access to diabetes diagnostic technologies is important in leading more people to obtain preventive care and counseling.

Women, people with higher levels of education and higher personal wealth, and people who are older or had high body mass index were more likely to be receiving evidence-based diabetes care. Diabetes in people with “normal” BMI is not uncommon in low- and middle-income countries, suggesting more need to focus on these individuals, the authors say.

The fact that diabetes-related medications are available at very low cost, and that individuals can reduce their risk through lifestyle changes, mean that cost should not be a major barrier, says Flood. In fact, studies have shown the medications to be cost-effective, meaning that the cost of their early and consistent use is outweighed by the savings on other types of care later.

Published in Science Advances, the paper explores the ongoing “replication crisis” in which researchers have discovered that many findings in the fields of social sciences and medicine don’t hold up when other researchers try to repeat the experiments.

The paper reveals that findings from studies that cannot be verified when the experiments are repeated have a bigger influence over time. The unreliable research tends to be cited as if the results were true long after the publication failed to replicate.

“We also know that experts can predict well which papers will be replicated,” write the authors Marta Serra-Garcia, assistant professor of economics and strategy at the Rady School and Uri Gneezy, professor of behavioral economics also at the Rady School. “Given this prediction, we ask ‘why are non-replicable papers accepted for publication in the first place?'”

Their possible answer is that review teams of academic journals face a trade-off. When the results are more “interesting,” they apply lower standards regarding their reproducibility.

The link between interesting findings and nonreplicable research also can explain why it is cited at a much higher rate — the authors found that papers that successfully replicate are cited 153 times less than those that failed.

“Interesting or appealing findings are also covered more by media or shared on platforms like Twitter, generating a lot of attention, but that does not make them true,” Gneezy said.

Serra-Garcia and Gneezy analyzed data from three influential replication projects which tried to systematically replicate the findings in top psychology, economic and general science journals (Nature and Science). In psychology, only 39 percent of the 100 experiments successfully replicated. In economics, 61 percent of the 18 studies replicated as did 62 percent of the 21 studies published in Nature/Science.

With the findings from these three replication projects, the authors used Google Scholar to test whether papers that failed to replicate are cited significantly more often than those that were successfully replicated, both before and after the replication projects were published. The largest gap was in papers published in Nature/Science: non-replicable papers were cited 300 times more than replicable ones.

When the authors took into account several characteristics of the studies replicated — such as the number of authors, the rate of male authors, the details of the experiment (location, language and online implementation) and the field in which the paper was published — the relationship between replicability and citations was unchanged.

They also show the impact of such citations grows over time. Yearly citation counts reveal a pronounced gap between papers that replicated and those that did not. On average, papers that failed to replicate are cited 16 times more per year. This gap remains even after the replication project is published.

“Remarkably, only 12 percent of post-replication citations of non-replicable findings acknowledge the replication failure,” the authors write.

The influence of an inaccurate paper published in a prestigious journal can have repercussions for decades. For example, the study Andrew Wakefield published in The Lancet in 1998 turned tens of thousands of parents around the world against the measles, mumps and rubella vaccine because of an implied link between vaccinations and autism. The incorrect findings were retracted by The Lancet 12 years later, but the claims that autism is linked to vaccines continue.

The authors added that journals may feel pressure to publish interesting findings, and so do academics. For example, in promotion decisions, most academic institutions use citations as an important metric in the decision of whether to promote a faculty member.

This may be the source of the “replication crisis,” first discovered the early 2010s.

“We hope our research encourages readers to be cautious if they read something that is interesting and appealing,” Serra-Garcia said. “Whenever researchers cite work that is more interesting or has been cited a lot, we hope they will check if replication data is available and what those findings suggest.”

Gneezy added, “We care about the field and producing quality research and we want to it to be true.”