Mobile phone use may affect semen quality

Sample of human spermatozoa used in the study by Serge Nef and Rita Rahban (2023), researcher at the Department of Genetic Medicine and Development of the UNIGE Faculty of Medicine and at the SCAHT - Swiss Centre for Applied Human Toxicology.
Image Credit: Rita Rahban

Does electromagnetic radiation emitted by mobile phones affect semen quality? While various environmental and lifestyle factors have been proposed to explain the decline in semen quality observed over the last fifty years, the role of mobile phones has yet to be demonstrated. A team from the University of Geneva (UNIGE), in collaboration with the Swiss Tropical and Public Health Institute (Swiss TPH), has published a major cross-sectional study on the subject. It shows that frequent use of mobile phones is associated with a lower sperm concentration and total sperm count. However, researchers did not find any association between mobile phone use and low sperm motility and morphology. Read the results in Fertility and Sterility.

Semen quality is determined by the assessment of parameters such as sperm concentration, total sperm count, sperm motility and sperm morphology. According to the values established by the World Health Organization (WHO), a man will most probably take more than one year to conceive a child if his sperm concentration is below 15 million per milliliter. In addition, the percentage chance of pregnancy will decrease if the sperm concentration is below 40 million per milliliter.

Many studies have shown that semen quality has decreased over the last fifty years. The sperm count is reported to have dropped from an average of 99 million sperm per milliliter to 47 million per milliliter. This phenomenon is thought to be the result of a combination of environmental factors (endocrine disruptor, pesticides, radiation) and lifestyle habits (diet, alcohol, stress, smoking).

Amazon deforestation linked to long distance climate warming

Amazon Forest seen from the Amazon Tall Tower Observatory, a scientific research facility in the Amazon rainforest of Brazil. 
Photo Credit Dr Jess Baker, University of Leeds.

Deforestation in the Amazon causes land surfaces up to 100 kilometers away to get warmer, according to a new study.

The research, by a team of British and Brazilian scientists, led by Dr Edward Butt at the University of Leeds, suggests that tropical forests play a critical role in cooling the land surface - and that effect can play out over considerable distances. 

It is known that when tropical forests are cleared, the climate in the immediate vicinity gets warmer.  

In this latest study, the researchers wanted to know if deforestation in the Amazon was resulting in climate warming further afield, and the study examined the impact of forest loss on sites up to 100 kilometers away. 

Researchers Show SARS-Cov-2 Infection Affects Energy Stores in the Body, Causing Organ Failure

Jonathan C. Schisler, PhD
Photo Credit: Courtesy of UNC

An international research team, including Jonathan C. Schisler, PhD, in the UNC School of Medicine, has found how SARS-CoV-2 causes widespread “energy outages” throughout major organs, and how these effects contribute to debilitating long COVID symptoms.

The lungs were once at the forefront of SARS-Cov-2 research, but as reports of organ failure and other serious complications poured in, scientists set out to discover how and why the respiratory virus was causing serious damage to the body’s major organs, including the lungs.

An interdisciplinary COVID-19 International Research Team (COV-IRT), which includes UNC School of Medicine’s Jonathan C. Schisler, PhD, found that SARS-CoV-2 alters mitochondria on a genetic level, leading to widespread “energy outages” throughout the body and its major organs. Their findings, published in Science Translational Medicine, explain how these effects contribute to long COVID symptoms and point to new therapeutic targets.

“We found that at peak infection time, there are distinct changes in different regions of the brain, including is a large decrease in mitochondrial genes in the cerebellum, the part of the brain that controls our muscles, balance, cognition, and emotion” said Schisler, assistant professor of pharmacology and member of the UNC McAllister Heart Institute. “The lung is the primary site of infection, but molecular signals are being transmitted affecting the entire body, with the heart, kidney, and liver being more affected than others, even long after the virus is gone.”

Sets of neurons work in sync to track ‘time’ and ‘place,’ giving humans context for past, present and future

Illustration Credit: MasterTux

Two studies led by UCLA researchers offer new insights into the way neurons in the human brain represent time and space – the most basic ingredients of consciousness of human existence and the primary dimensions of experience that allow us to reconstruct the past and envision the future.

The new findings are based on recordings of the activity of single neurons in the brain, from studies led by Dr. Itzhak Fried, a neurosurgeon and researcher at the UCLA David Geffen School of Medicine, is the senior author of two articles in Cell Reports. Patients who had undergone surgical placement of special depth electrodes developed and implanted by Fried for surgical treatment of intractable epilepsy agreed to perform cognitive tasks while their brain cell activity is recorded for these studies.

Neurons that act as the brain’s GPS system – termed “place cells” and “grid cells” – were discovered initially in rodents, similar findings later described in humans by Fried and colleagues at UCLA in collaboration with Dr. Michael Kahana, professor of Psychology at the University of Pennsylvania and a co-senior author of one of the new studies. The brain’s clock cells, or “time cells,” were identified in more recent years.

New genes linked to ADHD identified potentially paving the way for new treatments

Image Credit: Braňo

Several new genes associated with conditions such as Attention-deficit hyperactivity disorder (ADHD) have been identified, unearthing a significant connection between these disorders and our immune system that could lead to new treatments. The research from the University of Surrey also confirms the role of gene ADGRL3 in conditions such as ADHD, giving scientists a greater understanding of its workings.

During this innovative study, scientists led by Dr Matt Parker from Surrey set out to understand more about ADGRL3, a gene closely linked to ADHD and other ‘externalizing’ disorders, in promoting behaviors such as substance abuse, which can be associated with the conditions. Through this work, scientists identified several new genes related to externalizing disorders, which could lead to the development of new medication to lessen the impact on individuals.

DNA organization influences the growth of deadly brain tumors in response to neuronal signals

Silvia Remeseiro
Photo Credit: Mattias Pettersson

A pioneering study at Umeå University, Sweden, has unveiled that the 3D organization of DNA can influence the progression of the aggressive brain tumor known as glioblastoma. Having identified the factors that glioblastoma uses to respond to neurons by growing and spreading, this discovery paves the way for further research into new treatments for brain tumors.

"We have now identified the most important factors behind how the tumor responds to nerve cells, thus becoming more dangerous. These findings offer hope in our long-term battle against this difficult-to-treat cancer, for which the prognosis has not improved in decades," comments Silvia Remeseiro, Wallenberg fellow at WCMM, Assistant Professor at Umeå University, and lead author of the study.

Glioblastoma is the most fatal type of brain tumor among adults and there is currently no curative treatment. Glioblastoma patients typically face a survival of roughly one-year post-diagnosis. Even following current treatment regimes, which include surgery, radiotherapy and chemotherapy, a mere four per cent of patients are still alive five years after diagnosis.

Pinpointing HIV immune response

HIV, the AIDS virus (yellow), infecting a human cell
Image Credit: National Cancer Institute

New research combining computer modeling and experiments with macaques shows the body’s immune system helps control human immunodeficiency virus (HIV) infections largely by suppressing viral production in already infected cells while also killing viral infected cells, but only within a narrow time window at the start of a cell’s infection.

“To eliminate HIV, we have to understand how the immune system attempts to control the infection,” said Ruy M. Ribeiro, a theoretical biologist at Los Alamos National Laboratory who led the development of the model underpinning the research. Ribeiro is the corresponding author of the paper about the findings, published in Nature Communications.

The research team included Los Alamos Senior Fellow Alan S. Perelson and a former Los Alamos postdoctoral researcher now at the Fred Hutchinson Cancer Research Center. Their collaborators at the University of Pittsburg managed the experiments with macaques infected with simian immunodeficiency virus (SIV) to validate the model. SIV infections in monkeys behave the same way as HIV in humans.

Giant planets cast a deadly pall

Artist's depiction of a star system that is crowded with giant planets.
Illustration Credit: NASA/Dana Berry

Giant gas planets can be agents of chaos, ensuring nothing lives on their Earth-like neighbors around other stars. New studies show, in some planetary systems, the giants tend to kick smaller planets out of orbit and wreak havoc on their climates. 

Jupiter, by far the biggest planet in our solar system, plays an important protective role. Its enormous gravitational field deflects comets and asteroids that might otherwise hit Earth, helping create a stable environment for life. However, giant planets elsewhere in the universe do not necessarily protect life on their smaller, rocky planet neighbors. 

A new Astronomical Journal paper details how the pull of massive planets in a nearby star system are likely to toss their Earth-like neighbors out of the “habitable zone.” This zone is defined as the range of distances from a star that is warm enough for liquid water to exist on a planet’s surface, making life possible.

Unlike most other known solar systems, the four giant planets in HD 141399 are farther from their star. This makes it a good model for comparison with our solar system where Jupiter and Saturn are also relatively far from the sun.  

“It’s as if they have four Jupiters acting like wrecking balls, throwing everything out of whack,” said Stephen Kane, UC Riverside astrophysicist and author of the journal paper. 

Researchers observe wolves hunting and killing sea otters and harbor seals on Alaska’s Katmai coast

Wolf with a sea otter on Alaska's Katmai coast.
Photo Credit: Kelsey Griffin

Firsthand observations of a wolf hunting and killing a harbor seal and a group of wolves hunting and consuming a sea otter on Alaska’s Katmai coast have led scientists to reconsider assumptions about wolf hunting behavior.

Wolves have previously been observed consuming sea otter carcasses, but how they obtain these and the frequency of scavenging versus hunting marine prey is largely unknown. Scientists at Oregon State University, the National Park Service and Alaska Department of Fish and Game are beginning to change that with a paper just published in Ecology.

In the paper, they describe several incidents they observed involving wolves and marine mammals in Katmai National Park that they believe haven’t been previously documented:

The importance of the Earth's atmosphere in creating the large storms that affect satellite communications

Illustration Credit: ERG Science Team

A study from an international team led by researchers from Nagoya University in Japan and the University of New Hampshire in the United States has revealed the importance of the Earth’s upper atmosphere in determining how large geomagnetic storms develop. Their findings reveal the previously underestimated importance of the Earth’s atmosphere. Understanding the factors that cause geomagnetic storms is important because they can have a direct impact on the Earth’s magnetic field such as causing unwanted currents in the power grid and disrupting radio signals and GPS. This research may help predict the storms that will have the greatest consequences. 

Scientists have long known that geomagnetic storms are associated with the activities of the Sun. Hot charged particles make up the Sun's outer layer, the one visible to us. These particles flow out of the Sun creating the ‘solar wind’, and interact with objects in space, such as the Earth. When the particles reach the magnetic field surrounding our planet, known as the magnetosphere, they interact with it. The interactions between the charged particles and magnetic fields lead to space weather, the conditions in space that can affect the Earth and technological systems such as satellites.