People who have autosomal-dominant Alzheimer’s suffer an early-onset, genetic form of the disease, developing mild cognitive impairment by the time they reach their mid-40s and full-blown dementia at a median age of 49. Certain rare individuals, however, who carry one of the genes that cause autosomal-dominant Alzheimer’s are nevertheless inexplicably resistant to the throes of dementia for decades. Now researchers at the University of Antioquia in Medellín, Colombia, Harvard Medical School in Boston, and University Medical Center Hamburg-Eppendorf in Germany have shown how it works. One of these rare resisters, a man from Colombia, carried the PSEN1-E280A gene mutation known to drive early-onset Alzheimer’s. But he died at 72 with only mild cognitive impairment. That’s because he also carried a rare genetic variant known as RELN-COLBOS, which the researchers showed made him resilient. The hope is that this protective pathway could also be targeted therapeutically and improve outcomes for anyone with Alzheimer’s. Nature Medicine

Researchers at Washington University School of Medicine in St. Louis and Stanford University in Palo Alto, California, have identified a potential brain imaging biomarker of major depressive disorder, one of the leading causes of disability worldwide. In a series of clinical trials involving brain scans of people suffering, they found that the fMRI could detect severe depression on the basis of aberrant signaling between several brain regions. They also showed that daily administration of neurotherapy with transcranial magnetic stimulation or TMS (not a new solution) could restore normal brain patterns and alleviate the symptoms of depression. “Our results offer a pathway for identifying and treating mechanisms of neuropsychiatric diseases,” they write. PNAS

Active-duty U.S. soldiers serving in war zones are twice as likely to suffer post-traumatic stress disorder (PTSD) as the average American. So how do we better protect the wellbeing of returning soldiers and honor their valor and sacrifice? A new study by researchers at the Walter Reed Army Institute of Research in Silver Spring, Maryland, could help. Analyzing the blood serum of 180 active-duty soldiers and 340 veterans, many of whom suffer PTSD and all of whom served in active theaters of war during U.S. combat missions to Iraq or Afghanistan, the researchers identified reproducible molecular markers of PTSD—genetic, epigenetic, microRNA, metabolic, and proteomic. Those markers could be mapped to pathological changes including inflammation, oxidative stress, metabolic dysregulation, and blood vessel growth. “Such a systems-level understanding of PTSD can help to address PTSD-associated dysfunctions in a concerted approach and may contribute to developing prevention, diagnosis, and treatment strategies,” the researchers write. Cell Reports Medicine

A fascinating study involving 3,776 pairs of same-sex twins in Denmark (both identical and non-identical) shows that when one twin suffers some severe physical trauma as an adult, such as injuries in a car accident or broken bones from a bad fall, they are significantly more likely to die sooner or to develop immune-mediated diseases or cancer compared with their twin—even decades later. This may be associated with the rapid and almost wholesale activation of the innate immune system and suppression of the adaptive immunity triggered by the trauma, according to researchers at Rigshospitalet teaching hospital in Copenhagen who led the study. “This may leave an immunological imprint that goes beyond the obvious injuries and with long-term implications for the immune system,” they write. JAMA Surgery

Some 42 million people every year suffer concussions, including hundreds of thousands of American athletes involved in soccer, skiing, equestrian sports, football, boxing, and other sports. They are a major health concern and have been linked to worse long-term cognitive outcomes, but diagnosing a concussion and its severity and prognosis is not easy. Mild traumatic brain injuries don’t typically show up on a brain MRI or head CT scan, and there are no validated blood biomarkers of concussion. Now scientists at the Chinese Academy of Sciences in Beijing and Georgia Institute of Technology in Atlanta have developed a skull cap sensor array, potentially embedded in a helmet, that could detect the exact distribution of blunt force impacts to the head and potentially allow injuries to be electronically detected in real-time—though the technology has yet to be field tested. Science Advances

Food spoilage is a major economic and environmental problem—the world wastes some 1.4 billion tons of food each year. The production of this fruitless agriculture consumes a fifth of the world’s freshwater, uses almost a third of global agricultural land, and contributes 8 percent of all greenhouse gas emissions. Researchers at Kadir Has University and Koç University in Istanbul have designed an elegant solution to attack the problem by creating a simple, low-cost, wireless sensor that can be embedded into food packaging to tell someone on demand via their mobile phone whether the food is still fresh. They inserted their sensors into packages of fresh chicken and beef and demonstrated that meat stored in the freezer showed no change in electronic response over three days while packages of meat stored at room temperature gave a signal that was 700 percent stronger in that time. Yuck! Nature Food

Almost anyone can help save a life if they are trained to administer cardiopulmonary resuscitation (CPR) and happen to be there when someone is suffering a heart attack. Despite decades of efforts to train the public, however, typically only a fifth of all people worldwide who suffer heart attacks actually benefit from a bystander who knows CPR. Now the International Liaison Committee on Resuscitation has issued a scientific statement that says you are never too young to learn—literally! They call for CPR training to begin as early as age four, and they say even children who are only 10–12 years old can administer effective chest compressions and blow enough air into the lungs on training mannequins. Circulation

Recycling non‐biodegradable waste for building materials is an ecologically benign, smart approach to sustainable development, and past efforts have focused on everything from packing peanuts to plastic bottles. And now even used diapers! Researchers at the University of Kitakyushu in Japan showed that shredded disposable diaper waste would make a good composite building material. In a pilot project, they built a house adhering to Indonesian building standards and incorporating a significant amount of the material into its structural and architectural building components. “There is a need for policies that would broaden people’s access to building materials that are both appropriate and economical,” they write. We suspect they may need to broaden some minds, too. Scientific Reports

Front view of the prototype house. Courtesy Muhammad Arief Irfan