Alzheimer's disease can be diagnosed before symptoms emerge

Oskar Hansson, Professor of Neurology Lund University 
Photo Credit: Kennet Ruona

A large study led by Lund University in Sweden has shown that people with Alzheimer's disease can now be identified before they experience any symptoms. It is now also possible to predict who will deteriorate within the next few years. The study is published in Nature Medicine, and is very timely in light of the recent development of new drugs for Alzheimer's disease.

It has long been known that there are two proteins linked to Alzheimer’s – beta-amyloid, which forms plaques in the brain, and tau, which at a later stage accumulates inside brain cells. Elevated levels of these proteins in combination with cognitive impairment have previously formed the basis for diagnosing Alzheimer's.

“Changes occur in the brain between ten and twenty years before the patient experiences any clear symptoms, and it is only when tau begins to spread that the nerve cells die and the person in question experiences the first cognitive problems. This is why Alzheimer's is so difficult to diagnose in its early stages”, explains Oskar Hansson, senior physician in neurology at Skåne University Hospital and professor at Lund University.

He has now led a large international research study that was carried out with 1,325 participants from Sweden, the US, the Netherlands and Australia. The participants did not have any cognitive impairment at the beginning of the study. By using PET scans, the presence of tau and amyloid in the participants' brains could be visualized. The people in whom the two proteins were discovered were found to be at a 20-40 times higher risk of developing the disease at follow-up a few years later, compared to the participants who had no biological changes.

Friendly monkeys have friendly microbes

More sociable monkeys have a higher abundance of certain beneficial gut bacteria, and a lower abundance of potentially disease-causing bacteria, new research has found.

The study involved analyzing social network data from a population of non-captive macaques on the island of Cayo Santiago, off Puerto Rico, and combining this with sequencing data to assess their individual gut microbiota.

The researchers found that monkeys that engage in social interactions were more likely to have an abundance of gut microbes that are known to benefit the immune system, and were less likely to have an abundance of potentially harmful bacteria. The analyses controlled for other factors that could affect the microbiome, including age, season, sex and rank within the group’s hierarchy.

The study was conducted by Dr Katerina Johnson at the University of Oxford's Department of Psychiatry, in collaboration with Dr Karli Watson from the University of Colorado Boulder, alongside Oxford professors Robin Dunbar and Philip Burnet.

Linking Mass Extinctions to the Expansion and Radiation of Land Plants

Ymer Island, Greenland, during the collection of the Heintzbjerg sample sequence used in this study. In the foreground looking down the slope is the Zoologdalen Formation. The body of water is the Dusen Fjord, which separates the northern and southern portions of Ymer Island.
Photo Credit: John Marshall, University of Southampton.

The Devonian Period, 419 to 358 million years ago, was one of the most turbulent times in Earth’s past and was marked by at least six significant marine extinctions, including one of the five largest mass extinctions ever to have occurred. Additionally, it was during the Devonian that trees and complex land plants similar to those we know today first evolved and spread across the landscape. This evolutionary advancement included the development of significant and complex root systems capable of affecting soil biogeochemistry on a scale the ancient Earth had yet to experience.

It has been theorized that these two seemingly separate events, marine extinctions and plant evolution and expansion, were intricately linked in the Devonian. Specifically, it has been proposed that plant evolution and root development occurred so rapidly and on such a massive scale that nutrient export from the land to the ancient oceans would have drastically increased. This scenario is seen in modern systems where anthropogenically sourced nutrient export has vastly increased the nutrient load into areas such as the Gulf of Mexico and the Great Lakes, leading to large-scale algal blooms that ultimately deplete the oxygen in the water column. This effect, known as eutrophication, magnified on a global scale, would have been catastrophic to ancient oceans, fueling algal blooms that would have depleted most of the ocean’s oxygen.

Breathing may measurably modulate neural responses across brain

Wenyu Tu, co-author on the eLife paper and doctoral student in neuroscience in the Huck Institutes of the Life Sciences, sets up a functional MRI experiment. Functional MRI was used in conjunction with neuronal electrophysiology to identify a link between respiration and neural activity changes.
Photo Credit: Kelby Hochreither/Penn State

Mental health practitioners and meditation gurus have long credited intentional breathing with the ability to induce inner calm, but scientists do not fully understand how the brain is involved in the process. Using functional magnetic resonance imaging (fMRI) and electrophysiology, researchers in the Penn State College of Engineering identified a potential link between respiration and neural activity changes in rats.

Their results were made available online ahead of publication in eLife. The researchers used simultaneous multi-modal techniques to clear the noise typically associated with brain imaging and pinpoint where breathing regulated neural activity.

“There are roughly a million papers published on fMRI — a non-invasive imaging technique that allows researchers to examine brain activity in real time,” said Nanyin Zhang, founding director of the Penn State Center for Neurotechnology in Mental Health Research and professor of biomedical engineering. “Imaging researchers used to believe that respiration is a non-neural physiological artifact, like a heartbeat or body movement, in fMRI imaging. Our paper introduces the idea that respiration has a neural component: It affects the fMRI signal by modulating neural activity.”

By scanning the brainwaves of rodents in a resting state under anesthesia using fMRI, researchers revealed a network of brain regions involved in respiration.

Scientists Created Model to Determine Risks of Sudden Cardiac Arrest

According to Maksim Kashtanov, Sverdlovsk doctors perform 20-30 operations a year for this genetic disease.
Photo Credit: from Maksim Kashtanov's personal archive

European and Russian scientists have developed a model for predicting the risks of sudden cardiac arrest after alcohol septal ablation (ASA) for hypertrophic obstructive cardiomyopathy (HOCM). In other words, after surgery to remove a hypertrophic fragment of the left ventricular septum, which prevents normal blood flow to the aorta. The created model is a new word in science: before that the regularities of sudden cardiac arrest after ASA have not been investigated, the modern system of risk assessment for postoperative patients was absent. Meanwhile, HOCM is the cause of 30% of cases of sudden cardiac arrest.

The researchers' recommendations will contribute to the timely identification of patients at risk of sudden cardiac arrest after alcohol septal ablation and to the most effective treatment of hypertrophic obstructive cardiomyopathy. An article about the research was published in the American Journal of Cardiology.

The researchers analyzed the medical histories of more than 1,830 patients seen in clinics in Germany, the Czech Republic, Denmark, the Netherlands, Great Britain, and Russia. The analysis covered the period from 1996 to 2021. The study is the most extensive and in-depth to date. In developing the model, the authors used Russian statistics that have been forming since 2001. Data from Russia - Ekaterinburg and St. Petersburg - accounted for one-third of the statistical base of the study.

Rejuvenated immune cells can improve clearance of toxic waste from brain

Alzheimer’s, Parkinson’s and many other neurodegenerative diseases are marked by damaging clusters of proteins in the brain. Scientists have expended enormous effort searching for ways to treat such conditions by clearing these toxic clusters but have had limited success.

Now, researchers at Washington University School of Medicine in St. Louis has found an innovative way to improve waste clearance from the brain, and thereby possibly treat or even prevent neurodegenerative conditions. They showed that immune cells surrounding the brain influence how efficiently waste is swept out of the brain, and that such immune cells are impaired in old mice, and in people and mice with Alzheimer’s disease. Further, they found that treating old mice with an immune-stimulating compound rejuvenates immune cells and improves waste clearance from the brain.

The findings, published Nov. 9 in Nature, suggest a new approach to halting some of the effects of aging on the brain.

“Alzheimer’s has been studied for many years from the perspective of how neurons die, but there are other cells, such as immune cells on the periphery of the brain, that also may play a role in Alzheimer’s,” said senior author Jonathan Kipnis, PhD, the Alan A. and Edith L. Wolff Distinguished Professor of Pathology & Immunology and a BJC Investigator. “It doesn’t look likely that we will be able to revive dead or dying neurons, but the immune cells that sit on the borders of the brain are a feasible target for treating age-related brain diseases. They’re more accessible, and could be drugged or replaced. In this study, we treated aged mice with a molecule that can activate aged immune cells, and it worked in improving fluid flow and waste clearance from the brain. This holds promise as an approach to treating neurodegenerative diseases.”

Study provides first snapshot of global experiences with water insecurity

A new study by Northwestern anthropologists reveals the life-altering problems with water that have long gone hidden. 
Photo Credit: Charles Nambasi

Countries in Latin America, Asia and Africa have experienced severe droughts and unprecedented floods in the last year. New research from Northwestern University is the first to provide a more nuanced and global view of the experience of water insecurity.

In a new study published in The Lancet Planetary Health, scientists estimate that 436 million of the 3 billion adults represented by the survey sample were water insecure in 2021. The researchers also were able to pinpoint which groups experience the highest rates of water insecurity.

The study, led by Northwestern anthropologist Sera Young, uses data drawn from a nationally representative sample of nearly half the world’s population and a scale designed to measure water insecurity more holistically.

Young is an associate professor of anthropology and global health studies at Weinberg College of Arts and Sciences and a faculty fellow at the Institute for Policy Research (IPR) at Northwestern. Study collaborators include Hilary Bethancourt, assistant research professor of anthropology and IPR at Northwestern.

“These data bring a human face to the water sector, thereby revealing life-altering problems with water that have long gone hidden,” Young said.

Five times more rangers needed to manage protected areas worldwide by 2030

Ranger in Patagonia National Park, Chile.
Photo Credit: Jan Vincent Kleine, Rewilding Chile

The first study of its kind outlines an urgent need for larger numbers and better-supported protected area staff to ensure the health of life on Earth. In a new scientific paper published in Nature Sustainability, an international team of scientists, including one from University of Hawaiʻi at Mānoa, argue that there are not enough rangers and other staff to manage the current protected areas around the world. This is the first estimate of the global number of protected area personnel since 1999 and the first to specifically include rangers.

The study comes ahead of the global meeting of the Conference of the Parties in Montréal, Canada, December 7–15, which decides new targets for conservation. The authors urge governments, donors, private landowners and non-governmental organizations to increase the numbers of rangers and other staff five-fold in order to meet global biodiversity conservation goals that have economic, cultural and ecosystem benefits.

“Sufficient staffing is fundamental to the success of conservation initiatives,” said Eleanor Sterling, study co-author and director of the Hawaiʻi Institute of Marine Biology in the UH Mānoa School of Ocean and Earth Science and Technology (SOEST). “Protected area personnel have a critical role to play in ensuring implementation of this conservation strategy honors local and national values.”

The World Will Probably Warm Beyond the 1.5-Degree Limit. But Peak Warming Can Be Curbed.

More ambitious climate pledges could bring net-zero carbon dioxide emissions within this century, according to new research. Such a path is marked by rapid transformations throughout the global energy system and the scaling up of low-carbon technologies like renewables, nuclear energy, as well as carbon capture and storage, said the new study's authors.   
Photo Credit: Andrea Starr | Pacific Northwest National Laboratory

The world’s current climate pledges are insufficient to keep the goal of the 2015 Paris Agreement firmly within grasp. Global warming will likely surpass the 1.5-degree Celsius limit.

We are going to overshoot.

But countries can curb time spent in a warmer world by adopting more ambitious climate pledges and decarbonizing faster, according to new research led by scientists at the Department of Energy’s Pacific Northwest National Laboratory, the University of Maryland and the U.S. Environmental Protection Agency. Doing so, they warn, is the only way to minimize the overshoot.

While exceeding the 1.5-degree limit appears inevitable, the researchers chart several potential courses in which the overshoot period is shortened, in some cases by decades. The study published today in the journal Nature Climate Change, during the 2022 United Nations Climate Change Conference, also known as COP27, held in Sharm El Sheikh, Egypt.

“Let’s face it. We are going to breach the 1.5 degrees limit in the next couple of decades,” said corresponding author and PNNL scientist Haewon McJeon. “That means we’ll go up to 1.6 or 1.7 degrees or above, and we’ll need to bring it back down to 1.5. But how fast we can bring it down is key.”

Deforestation and grassland conversion are the biggest causes of biodiversity loss

Researchers rank the main drivers of global biodiversity loss. 
Photo Credit: Matthias Behr

The conversion of natural forests and grasslands to intensive agriculture and livestock is the biggest cause of global biodiversity loss. The next biggest drivers are the exploitation of wildlife through fishing, logging, trade and hunting - and then pollution. Climate change ranks fourth on land so far but second in oceans. This is the main result of an international study led by researchers from Universidad Nacional de Córdoba (UNC) in Argentina, Helmholtz Centre for Environmental Research (UFZ), German Centre for Integrative Biodiversity Research (iDiv) and the Natural History Museum London. The study, published in Science Advances, demonstrates that fighting climate change alone will not be enough to prevent the further loss of biodiversity.

Whilst climate change has rightly attracted attention for its catastrophic consequences for the natural world, it is currently only the fourth largest driver of biodiversity loss on land, followed by invasive alien species in fifth place. "This major new study, published during the COP27 climate summit, demonstrates clearly that fighting climate change alone will not be enough to prevent the further loss of biodiversity, and with it our future", says Dr Nicolas Titeux, one of the two first authors. "The various direct drivers should be addressed with similar ambition as the climate crisis and as a whole." Titeux currently works at the Luxembourg Institute of Science and Technology but conducted the major part of the study at the UFZ with funding from iDiv.