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Neuroscientists have long sought to explain how the brain correctly recognizes a stimulus despite the stimulus appearing under different circumstances with widely variable external factors. For example, with regard to olfactory stimuli, humans can…

A newly identified coronavirus, provisionally termed 2019-nCoV (an acronym for 2019 novel coronavirus) and subsequently named "severe acute respiratory syndrome coronavirus 2" (SARS-CoV-2), emerged in central China in November 2019. The disease…

Studies have shown that all classes of vertebrates—and even some invertebrate species—have the cognitive ability to discriminate among different quantities. For example, many kinds of studied animals can distinguish specific numbers of objects in…

Two new studies offer insight into why infection with SARS-CoV-2—the coronavirus that causes COVID-19—often leads to loss of smell, as well as why some people experience debilitating symptoms months after infection—a condition known as long COVID.…

Mercury and its compounds are highly toxic—that is, they cause harmful effects to living organisms. Mercury pollution is found in water, air, and soil worldwide. According to the United Nations Environment Programme, the top anthropogenic sources of…

Among the non-human animals that can be infected with—and become sick from—humans who have the SARS-CoV-2 virus that causes COVID-19 are deer, mink, hyenas, pigs, ferrets, dogs, cats, and primates such as rhesus macaque monkeys, baboons, and…

Bats are members of the order Chiroptera, which is the second-largest order of living mammals. The geographic distribution of these flying mammals is tremendous as well, ranging from the limit of trees in the Northern Hemisphere to the southern tips…

Genealogists and anthropologists have long disputed the provenance of domestic dogs (Canis lupus familiaris). Although genetic analyses and fossil evidence indicate that the domestic dog descended from the gray wolf (Canis lupus), the exact location…

A serious outbreak of equine herpesvirus type 1 (EHV-1), an infectious viral disease, is currently spreading among horse populations in Europe. This outbreak was first detected in Valencia, Spain, in February 2021 during a month-long equestrian…

In a breakthrough in the global fight against malaria, the World Health Organization (WHO) is recommending widespread administration of the first-ever malaria vaccine. This first-generation vaccine is intended for children considered to be at high…

In recent years, researchers have made considerable progress toward producing renewable energy in the form of hydrogen fuel through the electrolysis of water. In the most basic electrolytic cell, an electric current drives a chemical reaction at two…

Black holes pack an extraordinary amount of mass into a small spatial volume, resulting in gravitational fields so powerful that not even light can escape. These extreme objects occur as two distinct populations in the universe. The first, called…

Atmospheric ozone plays a critical role in the biosphere by absorbing harmful ultraviolet radiation in the stratosphere—the layer of the atmosphere about 10 to 50 km (6 to 30 mi) above Earth’s surface. Since the adoption of the Montreal Protocol in…

The diverse totality of microorganisms regularly found on and in the human body is collectively referred to as the human microbiota or microbial flora, with the largest microbial community in the body residing in the large intestine, or colon.…

In many animals, including humans, the sense of smell performs an important threat-detection function by helping to identify potential sources of harm, such as rotting food and toxic fumes. Little is known, however, about the initial neural…

A new mathematical approach called emulation dramatically decreases the amount of time necessary to solve equations describing key properties of atomic nuclei. The approach will help physicists run simulations far more quickly—and without the need…

For the first time, researchers have used the spin rates of black holes in the wide-ranging and ongoing search for dark matter. A recent study proposed that if a certain kind of dark matter particle, known as an ultralight boson, existed in a…

A new study has offered a possible explanation for a mysterious drop in brightness exhibited by the star Betelgeuse, an event known as the Great Dimming. Betelgeuse is an aged, red supergiant star located relatively close to Earth and readily…

The field of vaccination has been enhanced significantly by the successful development of two approved vaccines based on messenger RNA (mRNA) technologies. Prior to the COVID-19 pandemic that spread from China in 2019 to the rest of the world in…

The discovery of gravitational waves in 2015 revolutionized astronomy by opening up an entirely new way of studying extreme cosmic phenomena. Now researchers have reported the first evidence for a previously theorized but never-before-seen kind of…

Astronomers have found oddly synchronized star formation rates in 36 dwarf galaxies scattered around the Milky Way Galaxy. These dwarf galaxies all showed declines in star formation rates starting around six billion years ago, and then showed…

After a 203-day journey covering 472 million kilometers (293 million miles), NASA's Perseverance rover successfully landed on Mars on February 18, 2021. Perseverance is the largest and most sophisticated machine to ever land on another world.…

On April 7, 2021, the U.S. Centers for Disease Control and Prevention (CDC) announced that a genetic variant of SARS-CoV-2—the coronavirus that causes COVID-19—that was initially identified in the United Kingdom is the dominant form of the virus…

Scrap tires are a common waste material, although markets do exist. According to the U.S. Tire Manufacturers Association, of the roughly 270 million scrap rubber tires generated each year in this country, about 100 million tires are used as fuel;…

In response to the COVID-19 (coronavirus disease 2019) pandemic—which has dramatically affected the entire world, causing high morbidity, mortality, and massive social and economic disruption—and in addition to finding efficacious treatments for…

Researchers at Northwestern University, Evanston, Illinois, USA, have developed a virus catcher of sorts—that is, a sticky and absorbent surface coating that traps droplets and aerosols (microdroplets) that land on the coating. Most often, fine…

In 2012, Voyager 1 became the first humanmade object to leave the solar system when the space probe traversed the heliopause—the boundary at which the outflow of plasma from the Sun, known as solar wind, gives way to the collective solar winds from…

Ample evidence—from lake-, river-, and delta-like geological features to aqueous mineralogy—supports the inference that Mars once had vast quantities of water pooling and flowing across its surface. A longstanding question has centered around what…

Researchers at Purdue University in Indiana, United States, have developed the whitest white paint on record, based on its ultrahigh reflection rating. By incorporating a pigment called barium sulfate (BaSO4) at the highest concentration possible,…

Cosmochemists have discovered the oldest solid material known to exist on Earth. The material, stardust, consists of silicon carbide grains measuring around one micrometer in size. The grains date back approximately 7 billion years, or about 2.5…

There is a growing body of evidence that many of the thousands of prescription and over-the-counter medications ultimately make their way into water bodies and drinking-water supplies. Typical wastewater treatment plants may not be effective at…

Microplastics are raining down on national parks and other protected areas in the western United States at the rate of about 132 pieces of microplastic per square meter every day, according to a report in the journal Science (June 2020).…

In September 2020, researchers answered a longstanding question about why planetary nebulae display such a rich variety of shapes. Winds from aging stars produce planetary nebulae as the winds eject the stars' outer layers, shrouding the stars in…

The nearest images of the Sun obtained to date have revealed a new phenomenon, dubbed campfires, which appear as small, bright flickers of light all over the Sun's surface. The Solar Orbiter, a European Space Agency spacecraft launched in February…

Astronomers have discovered the closest black hole on record, located 1,100 light-years away from our solar system. This black hole is part of the star system HR 6819, which consists of two bright, bluish stars. On a clear, dark night, these stars…

Obscured by a hazy atmosphere 100 times thicker than Earth's, Venus is a notoriously difficult world to study. Ground temperatures on Venus exceed 450°C (842°F)—enough to melt lead and to have quickly degraded the Soviet robotic landers last placed…

Scientists have suggested a possible connection between ancient Neandertals (Homo neanderthalensis) and the severity of disease in patients affected by COVID-19. In short, certain genes acquired from Neandertals during instances of interbreeding…

The novel coronavirus SARS-CoV-2 that emerged in central China in late 2019 and subsequently spread across the world in 2020 led to the COVID-19 pandemic. The emergence of a previously unknown pathogen—such as the novel coronavirus—that could affect…

If you think converting seawater to fuels that can power ships is a fantasy, think again. Researchers at the U.S. Naval Research Laboratory in Washington, D.C., have, in fact, accomplished this feat. In addition, the U.S. Navy has received a patent…

Observations from the Hubble Space Telescope have solved a significant cosmic mystery that will help scientists better understand dark matter, an enigmatic substance theorized to outnumber normal matter at least fivefold. In 2018, astronomers were…

There has been substantial progress in the fight against certain drug-resistant organisms that cause serious, often fatal, diseases. However, two drug-resistant microbes—specifically, Candida auris (a fungal yeast) and Acinetobacter (a genus of…

Sickle cell disease, also termed sickle cell anemia, is a genetic disorder in which hypoxia, or oxygen deprivation, causes red blood cells (erythrocytes) to assume a rigid sickle shape, blocking blood flow within blood vessels. The disease results…

Astronomers have observed a galaxy from when the universe was only 1.4 billion years old that is remarkably similar to our Milky Way. Although lacking spiral arms like our galaxy, this distant galaxy does display a rotating disc and a starry,…

Fingerprint identification is a widely used forensic method for linking an individual to a crime scene. Investigators at a crime scene can find invisible (latent) fingerprints, which consist of natural skin oils, by "dusting" surfaces with carbon…

The earliest representatives of modern humans—those belonging to Homo sapiens—evolved from more archaic humans approximately 150,000–300,000 years ago in eastern Africa. During succeeding years, the geographical range of anatomically modern humans…

Mucus produced by the common garden snail (Helix aspersa) is green. The slime is not actually green in color but is “green” in terms of its environmentally friendly chemistry. It turns out that this snail’s mucus has chemical properties as a…

The ExoMars orbiter has detected a green glow emanating from excited oxygen molecules in the dayside atmosphere of Mars. The observations, gathered over a six-month period last year, confirm a four-decades-old prediction and represent the first time…

Heroin (C21H23NO5) is a white, crystalline powder synthesized from morphine, a natural alkaloid extracted from the seedpod of the Asian opium poppy plant, Papaver somniferum. It is a powerful opioid drug prepared by the addition of two acetyl groups…

A class of chemicals known as per- and polyfluoroalkyl compounds (PFAS) are particularly worrisome in the environment because they do not biodegrade. For this reason, scientists often refer to PFAS as “forever chemicals.” PFAS’s staying power…

Highly energetic light emitted by aged stars causes asteroids to keep spinning faster and faster to the point of disintegration, a new study finds. The findings help explain why white dwarf stars—remnants of Sunlike stars—often have metallic…

The majority of toxic pollution in the United States could potentially be eliminated by requiring a small number of extreme polluters to release pollutants at levels in line with those of comparable industrial facilities, according to a recent study…

Naturally ventilating a house, such as by opening doors and windows, has long been considered an effective strategy for exhausting indoor air pollutants. However, according to researchers reporting in the journal Science Advances (February 2020),…

Famously durable, diamond is the hardest natural substance that occurs in any significant abundance on Earth. Yet according to a new study, on the nanoscale—a scale size of just billionths of a meter—diamond can, in fact, be bent and deformed. This…

Over thousands of years of study of the human body through dissection and, more recently, modern-day imaging techniques, scientists have observed and analyzed various glands—that is, structures or organs that produce and secrete a substance or…

Using old data from the NASA spacecraft MESSENGER, researchers have demonstrated how to measure the average lifetime of a neutron from space. This finding is important because, despite decades of efforts, physicists still cannot definitively say how…

With the launch of the next-generation James Webb Space Telescope in October 2021, astronomers will finally be able to perceive distant galaxies that host quasars—the most luminous objects in the universe. Quasars shine forth with the equivalent…

During the initial stages of the COVID-19 pandemic, most restaurants and other dining facilities were shut down to contain the spread of the SARS-CoV-2 virus. By July 2020, however, indoor dining once again became an option for many…

In a surprising find, researchers have detected phosphine (PH3) in the atmosphere of Venus. This poisonous, colorless, flammable gas is nonetheless considered a strong sign of life, or "biosignature." Biosignatures are gases or combinations of gases…

Since the start of the COVID-19 (coronavirus disease 2019) pandemic, doctors and epidemiologists have identified a number of underlying medical conditions that are significantly correlated with severe illness from COVID-19. One such notable…

As offices, schools, health clubs, restaurants, hotels, and other facilities gradually reopen after shutdowns related to the COVID-19 pandemic, the public may confront yet another unmitigated health hazard: unsafe water from dormant or underused…

In December 2019, a new solar cycle started. Solar cycles are the roughly 11-year periods—documented going back nearly 270 years—over which the Sun’s magnetic activity peaks and troughs. This activity is marked by the formation of sunspots on the…

Over the course of history, smallpox has been among the most feared diseases of humankind. Caused by the variola virus (a DNA-containing member of the Poxviridae family) and spread by transfer through respiratory droplets during face-to-face…

The supermassive black hole at the center of the Milky Way serves as a unique laboratory for testing predictions of general relativity. In a new study, researchers report that a long-studied star—called S2 or sometimes S-02—moves in a rosette-shaped…

After a 40-year search, astronomers have identified the first star shown to pulsate on only one side. Many kinds of stars, called variables, undergo natural pulsations, or periodic changes in brightness that are visible across the whole star. The…

Molten iron rains from the evening skies of an exoplanet designated WASP-76b, according to a new study. WASP-76b is a gas giant—a large planet with a vast gaseous envelope, like Jupiter—located about 390 light-years from Earth. Astronomers used an…

Stellar explosions known as supernovae may be behind several anomalous rises in radiocarbon captured in tree rings over the past 40,000 years, according to a recent study that adds mounting evidence to the hypothesis that supernovae can impact…

Occurring in mammary glands and closely associated tissues, breast cancer is the most common cancer observed in women. For example, in the United States, approximately 1 in 8 women (about 12%) will develop invasive breast cancer over the course of…

A form of ultraviolet (UV) light holds promise as an innovative way to neutralize airborne SARS-CoV-2 particles and other viruses, potentially helping slow the COVID-19 pandemic that, to date, has caused over 1.3 million deaths globally. More…

Researchers from Drexel University in Pennsylvania, USA, have synthesized conductive and layered 2D materials known as MXenes (pronounced maxenes) using a water-free process. In doing so, scientists have opened up potential uses of MXenes as…

Poliomyelitis, more commonly called polio, is a devastating infectious disease of the central nervous system caused by the poliovirus (a type of enterovirus), which has three types in the wild (types 1, 2, and 3). Wild types 2 and 3 were declared…

Persistent changes in the Earth's climate that have been occurring primarily as a result of human-caused greenhouse-gas emissions since the mid-twentieth century have led to significant increases in infectious diseases in wildlife, both in terms of…

The Ebola virus comprises a group of pathogenic agents that cause severe and deadly hemorrhagic fevers in humans and other primates. During 2014 and 2015, an Ebola virus epidemic in West Africa—predominantly, the countries of Guinea, Liberia, and…

The United Nations has proclaimed 2019 the International Year of the Periodic Table of Chemical Elements (IYPT2019). The same year also marks the 150th anniversary of the publication of Russian chemist Dmitri Mendeleev’s periodic table, containing…

On July 20, 1969, the bulkily space-suited figure of astronaut Neil Armstrong descended the ladder of Apollo 11’s lunar lander, planted his boot in the Moon's gray dust, and declared: "That's one small step for a man, one giant leap for mankind."…

Researchers recently discovered a black hole with a mass estimated at 3.3 times the mass of the Sun, which is significantly less than the lowest-mass black holes previously detected with approximately 5 times the Sun's mass. The new finding opens…

The cancer death rate in the United States has fallen by 27% since 1991. According to the American Cancer Society, which compiled the data over a 25-year period from 1991 to 2016, a total of 2.6 million fewer individuals have died from cancer in the…

Plastic is a ubiquitous and life-saving product, but it is also rapidly becoming a significant environmental problem. Globally, less than 10 percent of plastics are recycled, about 12 percent are incinerated, and the vast majority are disposed of in…

For the first time, scientists have observed two molecules meeting and reacting to form new molecules. A team of chemists used lasers to slow down interacting molecules to temperatures far colder than outer space, enabling the team to observe a…

A compound found in cranberries, called cranberry proanthocyanidin (cPAC), when used in combination with antibiotics, such as tetracycline, prevents resistance to antibiotics in Escherichia coli and Pseudomonas aeruginosa, according to researchers…

After a decades-long search, astronomers have detected the signature of a molecule predicted as the first type to have ever formed in the universe. Called helium hydride and symbolized HeH+, this positively charged ion consists of a helium atom that…

At the Woranso-Mille paleontological site in northern Ethiopia, researchers have discovered a 3.8 million-year-old cranium (skull) belonging to a primitive hominin known as Australopithecus anamensis. Initially unearthed in 2016, but not reported…

Researchers recently announced the discovery of the farthest object ever identified within our solar system. Designated 2018 VG18 and nicknamed Farout, the object is located about 120 astronomical units (AU) from the Sun, or 120 times the average…

Eastern equine encephalitis is a rare infectious viral disease that primarily affects humans and equines (horses, mules, donkeys, and zebras). It is caused by a mosquito-borne virus (arbovirus) that is native to the eastern half of the United…

In a breakthrough for astronomy and physics, the Event Horizon Telescope (EHT) has obtained a direct image of a black hole. The first black hole captured in this manner is a supermassive one at the heart of a nearby galaxy, Messier 87. Further study…

Fentanyl is a synthetic opioid analgesic (pain reliever) that resembles morphine in its action. However, its drug potency is approximately 50 to 100 times more powerful than that of morphine, leading to high rates of both addiction and overdose…

Researchers have reached a key new milestone in the continuing search for worlds like Earth that could support life elsewhere in the universe. For the first time, water vapor has been detected in the atmosphere of an exoplanet that resides within…

The four main blood types (blood groups) found in humans are A, B, AB, and O. Two particular antigens (A and B) determine the specific blood type—A antigen is present in type A blood; B antigen is present in type B blood; both A and B antigens are…

Researchers Chi Ma of Caltech and Alan Rubin of the University of California at Los Angeles reported in the journal American Mineralogist (September 2019) the discovery in a meteorite of the first natural occurrence of the iron-carbide mineral…

Researchers at Duke University in North Carolina (United States) have developed a test for distinguishing lead isotopes found in coal fly ash from lead isotopes found in other lead-containing sources, such as paint. Fly ash is a fine particulate…

Researchers have produced carbon chips from waste plastic bags for use in making anodes for lithium-ion batteries, according to a report in ACS Omega (December 2018). For the most part, it is very difficult to break down (depolymerize) plastics into…

Macular degeneration is the most prevalent cause of vision impairment and loss among people aged 55 years and older. Also termed age-related macular degeneration (AMD), this serious eye condition damages the macula, which is the most sensitive part…

Marburg hemorrhagic fever (also referred to as Marburg virus disease) is a rare, exotic viral disease that affects both humans and nonhuman primates. The reservoir hosts of Marburg virus are African (or Egyptian) fruit bats (Rousettus aegyptiacus),…

Researchers have recorded the most massive neutron star on record, weighing as much as 2.17 Suns but packed into a city-sized sphere just 30 kilometers (19 miles) across. This astonishingly dense object is seemingly at the limits of the maximum mass…

Measles is a highly infectious and communicable disease that is most often contracted in childhood. The infective particle is a ribonucleic acid (RNA) virus—specifically, a paramyxovirus belonging to the genus Morbillivirus. Infected individuals…

New research from the U.S. National Aeronautics and Space Administration (NASA) predicts that the next decade will be a favorable period for human exploration due to lower risks of inclement "space weather"—a term that refers to radiation conditions…

Astronomers have arrived at a new, precise measurement of the mass of the Milky Way. Historical estimates have varied widely, from 500 billion times the mass of the Sun—a quantity known as a solar mass—to as high as three trillion solar masses. The…

Physicists have discovered a new state of matter described as a Cooper pair metal. Similar to an ordinary metal, this newfound state of matter conducts electricity with some resistance. However, the carriers of electric charge in this new state are…

Caused by the rod-shaped bacterium Mycobacterium tuberculosis and transmitted by airborne droplets from a diseased individual, tuberculosis (TB) is a chronic infectious disease of humans (and other animals) that destroys body tissue. When M.…

Among the most remarkable geophysical features in the solar system are four fissures—nicknamed tiger stripes—that streak across Saturn's moon Enceladus. Liquid water from this moon's interior erupts from these 130-kilometer- (80-mile-) long clefts…

Osteoprotegerin (OPG) is a protein that plays a central role in the regulation of bone mass. Also known as osteoclastogenesis inhibitory factor (OCIF), this naturally occurring protein [a soluble decoy receptor protein that belongs to the tumor…