Graphic by Maia Brown

Welcome back to campus! Check out this Research Recap to see what happened in the science field over winter break.

The concentration of CO2 before the dinosaur extinction

We have all heard that an asteroid impact caused the extinction of the dinosaurs about 66 million years ago. But scientists have found some other possible contributing factors before the impact that may have played a role in the dinosaurs’ demise due to preexisting instability. These factors include volcanic eruptions, climate change and sea-level change. To determine this, scientists at Northwestern examined the composition of fossilized seashells in Antarctica.

Scientists focused on fossilized seashells because they live for a short period and can capture “snapshots” of the ocean’s chemistry. The main component of shells is calcium carbonate (CaCO₃), which can be dissolved by carbon dioxide (CO2) in water. After collecting shells, researchers from Northwestern dissolved them to separate calcium from other elements and analyzed the components with high-precision scientific instruments. The results showed that the carbon dioxide level rose rapidly in the oceans before the mass extinction event, faster than experts expected.

Scientists believed that long-term eruptions from the Deccan Traps caused this rapid change in the ocean’s chemistry. The Deccan Traps, a volcanic province located in west-central India, is one of the largest volcanic features on Earth. The formation of the traps released massive amounts of volcanic gases about 66.25 million years ago. The large amounts of carbon dioxide it released acidified the oceans and affected seashells. Results from the study proved that a surge of carbon dioxide in the oceans happened before the mass extinction, and the Earth was already under stress. Scientists suggested that the environmental changes before the asteroid impact appeared to correlate with the eruption of the Deccan Traps. The study does not answer what caused the dinosaur extinction.

The study can provide insights into how the Earth may respond today to the human emission of carbon dioxide, rising sea levels and climate change. Scientists think that the past volcanic eruptions and acidification of oceans are good analogs to today’s human-caused carbon dioxide emissions. By understanding how the Earth responded in the past, we can better predict what might happen in the future.

Mental health conditions of surviving youths in fatal school shootings

School shootings in the United States are increasing. Little is known about the influence of those tragedies on the surviving youths. When thinking about victims of school shootings, people usually consider those who die or are injured but forget about the witnesses of the shooting. Researchers from Northwestern, Stanford and Yale found out that school shootings have long-lasting mental health effects on surviving youths.

According to their study, published in December, over 240,000 students in America experienced a school shooting in the last two decades. While policymakers consider the negative effects of gun violence, they often fail to realize the indirect costs of trauma to surviving youths who witness the deaths of their friends, classmates and teachers. Researchers, including Northwestern’s professors Hannes Schwandt and Molly Schnell, discovered that local exposure to fatal school shootings increases youth antidepressant use by 21.4% in the following two years. This increase in antidepressant use is striking and shows the long-lasting mental effects on survivors of school shootings that policymakers often neglect.

They examined the effects of 44 school shootings on youth antidepressant use with large-scale prescription data from 2006 to 2015. Besides the increase in youth antidepressant use, researchers also concluded that these effects are smaller in areas with a higher density of mental health providers who focus on behavioral rather than pharmacological interventions.

As public debates over gun control become hectic, this new study shows the underestimated true costs of school shootings to policymakers. It is essential to consider the mental health consequences of school shootings to the many surviving students when discussing the negative effects of gun violence. This study can pave the way for other analyses of school shootings effects that are not just direct statistics of deaths.

Personalized your weight control plan

Physicians and experts offer various weight loss plans with different diets and workout schedules, but finding the correct and efficient way to lose weight depends on individual habits and mindsets. According to the Centers for Disease Control and Prevention National Center for Health Statistics data brief in 2017, the prevalence of obesity was 39.8% among U.S. adults and 18.5 percent in youth from 2015 to 2016. So how should you personalize your weight loss plan to make it work best for you? Feinberg professor Robert Kushner’s six factors test may help.

In Professor Kushner’s book “Six Factors to Fit: Weight Loss that Works for You!,” he introduces personalized weight loss plans based on a person’s lifestyle, habits and mindset. After nearly 40 years of research and experience helping people lose weight, Professor Kushner explains that listening to people’s stories is the most important part because it helps him understand each person’s struggles with weight control and customize plans accordingly.

According to Professor Kushner, he clusters people’s struggle with weight loss into six factors: Convenient Diner, Fast Pacer, Easily Enticed Eater, Exercise Struggler, Self-Critic and All-or-Nothing Doer. These are major barriers to weight loss based on his research. To help people identify what hinders their quest for better health and style, he created the Six Factor Quiz to help evaluate which factors influence a person’s weight gain and need the most attention. The 27 statements in the quiz reflect a person’s eating habits, exercise patterns, and mindsets toward managing weight and health. The factor score determines the degree of attention a person needs to pay for a particular risk. For example, if you score higher than 13 in the Easily Enticed Eater factor, you are very likely to reach out for food whenever you have food around you, or you may eat out of habit rather than hunger and emotional stress may induce you to eat more.

Image courtesy of Professor Robert Kushner

Professor Kushner emphasizes that consistent weight loss based on a person’s lifestyle and habits can help manage weight and health better and create long-lasting changes to the body. By understanding your body and personalizing your weight control plan, Professor Kushner says that people can eat better, be more active and energetic, and enjoy a healthier life.