First, satellites in the mega constellation are categorized and the constellation design based on different satellite division is proposed. Satellites in the mega constellation are divided into 2 types, namely, the basic satellites and the accompanying satellites. All basic satellites that are surrounded by accompanying satellites are evenly distributed globally, and they have the same subsatellite trajectory. A basic satellite and its accompanying satellites are defined as a satellite group. The constellation is composed ...

If somebody complains that it hurts to think, they may be onto something, as mental exertion appears to be associated with unpleasant feelings in many situations, according to research published by the American Psychological Association. “Managers often encourage employees, and teachers often encourage students, to exert mental effort. On the surface, this seems to work well: Employees and students do often opt for mentally challenging activities,” said senior author Erik Bijleveld, PhD, of Radboud University. “From this, you may be tempted to conclude that ...

Drylands, found across every continent, cover about 45% of the Earth's land surface and support 38% of the human population. In these regions, precipitation is low and evaporation rates are typically high, leading to an arid or semi-arid climate. Due to scarce water resources and sparse vegetation, drylands present formidable challenges for agriculture and human habitation. As the climate continues to warm, drylands are rapidly expanding.  A particularly urgent problem in drylands is climate-driven soil degradation, which affects about 33% of the planet’s land surface. Drylands host ...

Dartmouth researchers have developed a self-powered pump that uses natural light and chemistry to target and remove specific water pollutants, according to a new report in the journal Science. As water enters the pump, a wavelength of light activates a synthetic molecular receptor designed to bond to negatively charged ions, or anions, a class of pollutants linked to metabolic disruptions in plants and animals. A second wavelength deactivates the receptors as water exits the pump and causes them to release the ...

The method used across the United States to wait-list children for heart transplants does not consistently rank the sickest patients first, according to a new study led by Stanford Medicine experts.  The study will publish online Aug. 5 in the Journal of the American College of Cardiology. Adding nuance to the wait-list system by accounting for more health factors could reduce children’s risk of dying while they await donor hearts, according to the study’s authors. A revision to the way donor hearts are assigned is already in process. The study adds evidence for why it is needed, they ...

Cervical cancer is a highly prevalent cancer, with approximately 500,000 new cases diagnosed each year. Shockingly, the number of individuals diagnosed with precursor lesions in the cervix—also known as cervical intraepithelial neoplasia (CIN)—is 20 times higher. As with many potentially malignant conditions, early diagnosis of cervical cancer can make all the difference in a patient’s life in terms of treatment outcomes. For this, developing effective, convenient, and easily available screening protocols for CIN and cervical cancer is of paramount importance. Currently, the two ...

Neutrinos are fundamental particles in the Standard Model of particle physics, notable for their extremely small masses and weak interactions with matter. They are important for answering fundamental questions about the universe, including why particles have mass and why there is more matter than antimatter. Despite being abundant, their weak interactions make their detection difficult, and hence they are called “ghost particles.” At any given moment, numerous neutrinos freely pass through the Earth and our bodies, which originate from the Sun or cosmic rays. Understanding their rare interactions with matter is crucial for obtaining a more complete picture ...

Melanin protects the skin—the body's largest organ and a vital component of the immune system—from the damaging effects of ultraviolet (UV) radiation. When the skin is exposed to UV radiation, melanin production is stimulated in melanocytes, with tyrosinase playing a key role in the biosynthetic pathway. However, disruptions in this pathway caused by UV exposure or aging can lead to excess melanin accumulation, resulting in hyperpigmentation. To address this, tyrosinase inhibitors that suppress melanin synthesis have become valuable in the cosmetic industry. Unfortunately, some of these compounds, ...

In an examination of the genetic material found in historic potato leaves, North Carolina State University researchers reveal more about the tit-for-tat evolutionary changes occurring in both potato plants and the pathogen that caused the 1840s Irish potato famine.  The study used a targeted enrichment sequencing approach to simultaneously examine both the plant’s resistance genes and the pathogen’s effector genes – genes that help it infect hosts – in a first-of-its-kind analysis. “We use small pieces of historic leaves with the pathogen ...

Caltech researchers have developed a new method to measure soil moisture in the shallow subterranean region between the surface and underground aquifers. This region, called the vadose zone, is crucial for plants and crops to obtain water through their roots. However, measuring how this underground moisture fluctuates over time and between geographical regions has traditionally relied on satellite imaging, which only gives low-resolution averages and cannot penetrate below the surface. Additionally, moisture within the vadose zone changes rapidly—a thunderstorm can saturate a region that dries ...

AURORA, Colo. (August 5, 2024) – In a first-of-its-kind study, a cohort of researchers, led by the University of Colorado Anschutz Medical Campus, evaluated the effects of state-level insulin out-of-pocket costs across states and payers and over time. The team found that state-level caps on insulin out-of-pocket costs do not significantly increase insulin claims for patients with Type 1 or patients using insulin to manage Type 2 diabetes. Study results could help inform policies aimed at better delivering cost-capped insulin to patients struggling with insulin affordability. Approximately ...

Parkinson’s disease is a neurodegenerative disease caused by the loss of neurons that produce dopamine, a neurotransmitter involved in motor control and cognitive function. As the global population ages, the number of Parkinson's disease patients is rapidly increasing. Parkinson's disease is induced by neuronal damage due to excessive production of reactive oxygen species. Suppression of reactive oxygen species generation is essential because it is fatal to dopaminergic neurons that manage dopamine neurotransmitters. ...

Light pollution disrupts circadian rhythms and ecosystems worldwide – but for plants, dependent on light for photosynthesis, its effects could be profound. Now scientists writing in Frontiers in Plant Science have found that exposure to high levels of artificial light at night makes tree leaves grow tougher and harder for insects to eat, threatening urban food chains. “We noticed that, compared to natural ecosystems, tree leaves in most urban ecosystems generally show little sign of insect damage. We were curious as to why,” said corresponding author Dr Shuang Zhang of the Chinese Academy of Sciences. “Here we show that in ...

Mental health screenings must be incorporated in routine prostate cancer diagnoses say University of South Australia researchers. The call follows new research that shows men need more supports both during and immediately after a diagnosis of prostate cancer.   Funded by Movember, the UniSA study tracked the scale and timing of mental health issues among 13,693 South Australian men with prostate cancer, finding that 15% of prostate cancer patients began mental health medications directly after a prostate cancer diagnosis, with 6% seeking help from mental health ...

WASHINGTON – Three high-impact steps could be taken by global health leaders to reshape the global regulatory framework and help address the pressing need for equitable access to diagnostics, therapeutics, and vaccines during public health emergencies, say a Georgetown global health law expert and a medical student. In their “Perspective” published today in the New England Journal of Medicine, Georgetown School of Health professor Sam Halabi, JD, and George O’Hara, a Georgetown medical student and David E. Rogers Student ...

Tokyo, Japan – Researchers from Tokyo Metropolitan University have taken a big step in solving the mystery around why animals evolve sex chromosomes. It had long been proposed that sex chromosomes evolve to reduce “sexual conflict,” the evolution of features which are sub-optimal for either sex. By using fruit flies, the team showed that genes on newly formed neo-sex chromosomes in fruit flies tend to evolve “sex-biased genes” which give sex-specific phenotypes.   Chromosomes are neatly packaged bundles of DNA that carry all the genetic material of an organism. While prokaryotes ...

A research team led by engineers at the University of Virginia School of Engineering and Applied Science is the first to explore how an emerging plant-based material, cellulose nanofibrils, could amplify the benefits of 3D-printed concrete technology. “The improvements we saw on both printability and mechanical measures suggest that incorporating cellulose nanofibrils in commercial printable materials could lead to more resilient and eco-friendly construction practices sooner rather than later,” said Osman E. Ozbulut, a professor in the Department of Civil and Environmental ...

Technology with roots going back to the Bronze Age may offer a fast and inexpensive solution to help achieve the United Nations climate goal of net zero emissions by 2050, according to recent Stanford-led research in PNAS Nexus. The technology involves assembling heat-absorbing bricks in an insulated container, where they can store heat generated by solar or wind power for later use at the temperatures required for industrial processes. The heat can then be released when needed by passing air through channels in the stacks of “firebricks,” thus allowing cement, steel, glass, and paper factories to run on renewable energy even when wind and sunshine ...

Patrick Sullivan, MD, FRANZCP, the Yeargan Distinguished Professor of Psychiatry and Genetics at the UNC School of Medicine, and researchers at the Karolinska Institutet in Stockholm, Sweden, have developed a comprehensive outline of the genetics of schizophrenia. The review was published in Nature Reviews Neuroscience. Schizophrenia is a neuropsychiatric disorder featuring recurrent episodes of psychosis – such as hallucinations, delusions, and disorganized thinking – with many patients developing apathy, social withdrawal, ...

In a new review paper, researchers from the Universities of Arizona, Oxford and Leeds analyzed dozens of previous studies into long COVID to examine the number and range of people affected, the underlying mechanisms of disease, the many symptoms that patients develop, and current and future treatments. Long COVID, also known as Post-COVID-19 condition, is generally defined as symptoms persisting for three months or more after acute COVID-19. The condition can affect and damage many organ systems, leading to severe ...

COLUMBUS, Ohio – The rising earth beneath the Antarctic Ice Sheet will likely become a major factor in future sea level rise, a new study suggests.  Despite feeling like a stationary mass, most solid ground is undergoing a process of deformation, sinking and rising in response to many environmental factors. In Antarctica, melting glacial ice means less weight on the bedrock below, allowing it to rise. How the rising earth interacts with the overlying ice sheet to affect sea level rise is not well-studied, said Terry Wilson, co-author of the study and a senior research scientist at the Byrd Polar and Climate Research Center ...

Rebecca Robbins, PhD, of the Division of Sleep and Circadian Disorders at Brigham and Women’s Hospital, is the senior author of a paper published in Psychiatry Research, “Exploring sleep difficulties, alcohol, illicit drugs, and suicidal ideation among adolescents with a history of depression.” How would you summarize your study for a lay audience? Suicide is one of the leading causes of death for adolescents in the U.S. We know, due to previous research, that difficulty falling asleep or waking up too early as well as abuse of prescription ...

  Giving children a right to be heard and taken seriously when parents separate could help couples reach sustainable child arrangements and relieve significant backlogs in the family court, avoiding unnecessary financial and emotional costs, a new study says. Mediation, court and legal processes should provide a forum for young people’s views on post-separation arrangements being considered for them to be aired independently and factored in wherever appropriate. Giving them more agency about decisions which affect their lives and futures will help families make more effective ...

A McGill-led study suggests that Earth's natural forces could substantially reduce Antarctica’s impact on rising sea levels, but only if carbon emissions are swiftly reduced in the coming decades. By the same token, if emissions continue on the current trajectory, Antarctic ice loss could lead to more future sea level rise than previously thought. The finding is significant because the Antarctic Ice Sheet is the largest ice mass on Earth, and the biggest uncertainty in predicting future sea levels is how this ice will respond to climate change. “With nearly 700 million people living in coastal areas and the potential ...

Scientists at Sanford Burnham Prebys and Salk Institute for Biological Studies have uncovered a new role for a protein known for its role in the brain helping control feelings of hunger or satiety, as well as in the liver to aid the body in maintaining a balance of energy during fasting. The new study shows that this protein also supports the maintenance of heart structure and function, but when it is overactive it causes thickening of the heart muscle, which is associated with heart disease. Excessive thickening of the heart muscle—known as cardiac hypertrophy—is often ...