How Cow Antibodies Are Helping Scientists Develop an HIV Vaccine

Researchers have long sought to develop an effective HIV vaccine. Several treatments have undergone clinical trials, but the only one that’s been even slightly successful, a 2009 study in Thailand, lowered HIV infection rates by only 30 percent.

But scientists haven’t given up hope.

An effective HIV vaccine could be “transformative,” Anthony Fauci, the director of the National Institute of Allergy and Infectious Disease, said in May. Fauci said modeling from the National Institutes of Health showed that even if a vaccine was only 50 percent effective, it could reduce the number of people living with HIV by 36 percent around the world in 15 years.

Last week, researchers released a study showing progress toward developing an effective vaccine. In their paper, which was published in the journal Nature, they describe their success in prompting a quick immune response to HIV — at least in four cows.

While it may seem a big leap from cows to humans, scientists are encouraged by the results.

Vaccines are made from the same germs that cause a disease. A vaccine is potent enough to prompt an immune response, but not so strong that it causes a recipient to become sick. When exposed to small amounts of a virus, a person’s immune system produces antibodies, which are proteins designed to kill the virus. Even after the virus goes away, the immune cells “remember” it and are able to produce antibodies quickly if a person is exposed to the virus again.

This tried-and-true method, which has helped to combat polio, measles, and the flu, hasn’t worked with HIV because the virus replicates very quickly, leading to dozens of different strains and substrains, and can remain latent in the body for long periods of time.

Antibodies that successfully combat HIV do exist, but only in about 10-20 percent of people infected with HIV. And they often take a long time to develop. When exposed to most viruses, people produce antibodies within a few days. But with HIV, it often takes more than two years.

A man is injected with a potential vaccine during phase III of a HIV vaccine in Thailand.

“One of, if not the major challenge in development of a safe and effective HIV vaccine, is the inability to elicit broadly neutralizing antibodies in humans,” Wayne Koff, president and CEO of the Human Vaccines Project, said in an email. Koff was not affiliated with the new study.

The goal of developing an effective vaccine hinges on prompting a person’s immune system to begin quickly producing what are called broadly neutralizing antibodies (bNAbs) in order to fight off infection.

And that’s where the cows come in.

The researchers, supported by NIH, thought cows might yield insights on fighting HIV when they looked at the structure of human bNAbs that were produced by people with long-term HIV infections. Specifically, they looked at a looped area on the antibodies called HCDR3.

One of the distinct features of the HIV virus is that it is surrounded by a thick envelope of sugars, called the glycan shield, that is hard for normal-sized antibodies to penetrate. The scientists realized that in the small percent of humans that do produce HIV bNAbs those antibodies have extra-long HCDR3 loops that can pierce through the glycan shield.

Antibodies in cows also have naturally long HCDR3 loops, though no one is quite sure why. One theory is, because cows have multiple stomachs with lots of bacteria, they need extra-powerful antibodies to protect them from infection.

The researchers injected the four cows with an HIV immunogen, a molecule that can prompt the HIV immune response. To their surprise, not only did the cows produce HIV bNAbs, but they produced them quickly — within 35 to 50 days. At just over a year, one cow produced bNAbs against 117 strains of HIV.

Read more at Seeker

NASA Posts Archive of Flight Test Videos on YouTube

A Lunar Lander Vehicle Flight with astronaut Neil Armstrong

Aviation geeks rejoice: There’s a whole new way to waste time.

NASA is marking 70 years of advanced aircraft testing by releasing a trove of old video from its Dryden Flight Research Center, the longtime home of the space agency’s atmospheric flight research.

The center, which was renamed for Apollo 11 commander Neil Armstrong in 2014, has posted dozens of short clips on its YouTube page this month. They include old films recently digitized as well as already-online video that has been moved to a more-accessible home, said Leslie Williams, a spokeswoman for the facility.

“The server that held those movies was becoming antiquated,” Williams said. “One of the best ways to preserve that video so other people could see it was to put it out on YouTube.”

The Armstrong center shares space with Edwards Air Force Base in the Mojave Desert east of Los Angeles. Established in 1946, it predates NASA and even the US Air Force, which was created in 1947 — the same year the first test flights were conducted.

It’s the home of the X-planes — high-speed, high-altitude experimental aircraft designed to push the limits of flight. They included the X-1, in which Chuck Yeager made the first supersonic flight in 1947, to the unmanned, 12-foot-long X-43, which hit nearly 7,000 mph in 2004. The latest, the X-57, is designed to test how well cleaner, quieter electric motors will work on manned aircraft.

The mostly-silent clips include footage of Armstrong himself, demonstrating a lunar lander trainer for reporters before his 1969 moon mission. You can watch test pilot Scott Crossfield descend from the bomb bay of a B-29 into the Douglas D-558 rocket plane slung underneath, shortly before it’s dropped from the mother ship. And there several clips of the X-15 space plane, in which several Air Force pilots earned astronaut wings for flights that topped 350,000 feet.

There were duds, too, like the X-3, a needle-nosed, stubby-winged craft nicknamed the Stiletto, which never lived up to its high-speed billing; and the XB-70 Valkyrie, a Mach 3 bomber design from the early 1960s. When the Pentagon passed on the Valkyrie, the two prototypes became test models for a future supersonic airliner.

And there are several lifting-body craft like the X-24, HL-10, and M2 series, which were steppingstones in the development of the space shuttles. It was a 1967 lifting-body crash, not included in this batch of video, that was featured in the opening credits of the 1970s television series “The Six Million Dollar Man.”

Read more at Seeker

Ultrathin device harvests electricity from human motion

Vanderbilt undergraduate Thomas Metke demonstrates the ultrathin energy harvesting device which is taped across his elbow. As he flexes his arm the current the device generates is displayed on the computer display.

Imagine slipping into a jacket, shirt or skirt that powers your cell phone, fitness tracker and other personal electronic devices as you walk, wave and even when you are sitting.

A new, ultrathin energy harvesting system developed at Vanderbilt University's Nanomaterials and Energy Devices Laboratory has the potential to do just that. Based on battery technology and made from layers of black phosphorus that are only a few atoms thick, the new device generates small amounts of electricity when it is bent or pressed even at the extremely low frequencies characteristic of human motion.

"In the future, I expect that we will all become charging depots for our personal devices by pulling energy directly from our motions and the environment," said Assistant Professor of Mechanical Engineering Cary Pint, who directed the research.

The new energy harvesting system is described in a paper titled "Ultralow Frequency Electrochemical Mechanical Strain Energy Harvester using 2D Black Phosphorus Nanosheets" published Jun.21 online by the journal ACS Energy Letters.

"This is timely and exciting research given the growth of wearable devices such as exoskeletons and smart clothing, which could potentially benefit from Dr. Pint's advances in materials and energy harvesting," observed Karl Zelik, assistant professor of mechanical and biomedical engineering at Vanderbilt, an expert on the biomechanics of locomotion who did not participate in the device's development.

Currently, there is a tremendous amount of research aimed at discovering effective ways to tap ambient energy sources. These include mechanical devices designed to extract energy from vibrations and deformations; thermal devices aimed at pulling energy from temperature variations; radiant energy devices that capture energy from light, radio waves and other forms of radiation; and, electrochemical devices that tap biochemical reactions.

"Compared to the other approaches designed to harvest energy from human motion, our method has two fundamental advantages," said Pint. "The materials are atomically thin and small enough to be impregnated into textiles without affecting the fabric's look or feel and it can extract energy from movements that are slower than 10 Hertz -- 10 cycles per second -- over the whole low-frequency window of movements corresponding to human motion."

Doctoral students Nitin Muralidharan and Mengya Li co-led the effort to make and test the devices. "When you look at Usain Bolt, you see the fastest man on Earth. When I look at him, I see a machine working at 5 Hertz," said Muralidharan.

Extracting usable energy from such low frequency motion has proven to be extremely challenging. For example, a number of research groups are developing energy harvesters based on piezoelectric materials that convert mechanical strain into electricity. However, these materials often work best at frequencies of more than 100 Hertz. This means that they don't work for more than a tiny fraction of any human movement so they achieve limited efficiencies of less than 5-10 percent even under optimal conditions.

"Our harvester is calculated to operate at over 25 percent efficiency in an ideal device configuration, and most importantly harvest energy through the whole duration of even slow human motions, such as sitting or standing," Pint said.

The Vanderbilt lab's ultrathin energy harvester is based on the group's research on advanced battery systems. Over the past 3 years, the team has explored the fundamental response of battery materials to bending and stretching. They were the first to demonstrate experimentally that the operating voltage changes when battery materials are placed under stress. Under tension, the voltage rises and under compression, it drops.

The team collaborated with Greg Walker, associate professor of mechanical engineering, who used computer models to validate these observations for lithium battery materials. Results of the study were published Jun. 27 in the journal ACS Nano in an article titled "The MechanoChemistry of Lithium Battery Electrodes."

These observations led Pint's team to reconstruct the battery with both positive and negative electrodes made from the same material. Although this prevents the device from storing energy, it allows it to fully exploit the voltage changes caused by bending and twisting and so produce significant amounts of electrical current in response to human motions.

The lab's initial studies were published in 2016. They were further inspired by a parallel breakthrough by a group at Massachusetts Institute of Technology who produced a postage-stamp-sized device out of silicon and lithium that harvested energy via the effect Pint and his team were investigating.

In response, the Vanderbilt researchers decided to go as thin as possible by using black phosphorus nanosheets: A material has become the latest darling of the 2D materials research community because of its attractive electrical, optical and electrochemical properties.

Because the basic building blocks of the harvester are about 1/5000th the thickness of a human hair, the engineers can make their devices as thin or as thick as needed for specific applications. They have found that bending their prototype devices produces as much as 40 microwatts per square foot and can sustain current generation over the full duration of movements as slow as 0.01 Hertz, one cycle every 100 seconds.

The researchers acknowledge that one of the challenges they face is the relatively low voltage that their device produces. It's in the millivolt range. However, they are applying their fundamental insights of the process to step up the voltage. They are also exploring the design of electrical components, like LCD displays, that operate at lower than normal voltages.

"One of the peer reviewers for our paper raised the question of safety," Pint said. "That isn't a problem here. Batteries usually catch on fire when the positive and negative electrodes are shorted, which ignites the electrolyte. Because our harvester has two identical electrodes, shorting it will do nothing more than inhibit the device from harvesting energy. It is true that our prototype will catch on fire if you put it under a blowtorch but we can eliminate even this concern by using a solid-state electrolyte."

One of the more futuristic applications of this technology might be electrified clothing. It could power clothes impregnated with liquid crystal displays that allow wearers to change colors and patterns with a swipe on their smartphone. "We are already measuring performance within the ballpark for the power requirement for a medium-sized low-power LCD display when scaling the performance to thickness and areas of the clothes we wear." Pint said.

Pint also believes there are potential applications for their device beyond power systems. "When incorporated into clothing, our device can translate human motion into an electrical signal with high sensitivity that could provide a historical record of our movements. Or clothes that track our motions in three dimensions could be integrated with virtual reality technology. There are many directions that this could go."

Read more at Science Daily

Jupiter’s complex transient auroras

Auroras at Jupiter.

Combined observations from three spacecraft show that Jupiter's brightest auroral features recorded to date are powered by both the volcanic moon Io and interaction with the solar wind.

At Earth, auroras are clearly driven by the solar wind that streams past the planet. But Jupiter's gigantic auroras -- magnitudes more powerful than those on Earth -- are believed to be mainly driven by factors within the Jovian system. Now, by combining observations from three spacecraft, scientists from an international collaboration led by a researcher at the RIKEN Nishina Center for Accelerator-Based Science have shown that the picture is complex -- volcanoes on Io, one of Jupiter's moons -- and the most active volcanic body in the solar system -- are responsible for powering some of Jupiter's brightest auroral features through interactions with the shock wave caused by the arrival of the solar wind.

To perform the study, the group looked at data from three space-based sources -- Japan's Hisaki satellite, an earth-orbiting extreme ultraviolet observatory that was launched into low-earth orbit in 2013, the Juno spacecraft, which entered into orbit around Jupiter in July 2016, and the Hubble Space Telescope, which took high-resolution far ultraviolet photos of Jupiter as Juno entered into orbit. By combining the data from the three spacecraft -- including snapshots taken by Hisaki at ten-minute intervals for a period of more than six months, the team was able to more precisely map out the process through which the sulfur gas emerging from Io's powerful volcanoes is stored in the area far from Jupiter, transiently accelerated, transferred toward Jupiter, and channeled into Jupiter's polar region where it drives the aurora. These findings were detected during a "transient brightening" of Jupiter's aurora -- with the phenomenon moving from the polar region toward the equator -- that was detected in May 2016, as Juno was approaching. The data showed that the energy from Io's gas emission was somehow transferred toward Jupiter at a speed approaching 400 to 800 kilometers per second in the equatorial region of the space around Jupiter.

Previous observations had been made combining the data from Hisaki and the HST had concluded that the solar wind had little to do with the transient auroras. "What is special about our observations," says lead author Tomoki Kimura, a Special Postdoctoral Researcher at RIKEN, "is that we were able to time the observations with the arrival of the Juno spacecraft into Jovian orbit. It turns out that Juno detected a shock wave originating from the solar wind, and this led us to infer that the solar wind was, along with Io, playing a role in the process by driving the energy toward Jupiter."

In the past, it was generally considered that the magnetic field of a rotating astronomical body is powerful enough to completely dominate azimuthal movements of energy and mass near it, but the team's findings challenge this assumption, as the energy seems to move from the area far from Jupiter toward Jupiter.. Moreover, this process seems to hold for other rotating bodies such as neutron stars.

Read more at Science Daily

The moon is front and center during a total solar eclipse

In the lead-up to a total solar eclipse, most of the attention is on the sun, but Earth's moon also has a starring role.

In the lead-up to a total solar eclipse, most of the attention is on the sun, but Earth's moon also has a starring role.

"A total eclipse is a dance with three partners: the moon, the sun and Earth," said Richard Vondrak, a lunar scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "It can only happen when there is an exquisite alignment of the moon and the sun in our sky."

During this type of eclipse, the moon completely hides the face of the sun for a few minutes, offering a rare opportunity to glimpse the pearly white halo of the solar corona, or faint outer atmosphere. This requires nearly perfect alignment of the moon and the sun, and the apparent size of the moon in the sky must match the apparent size of the sun.

On average, a total solar eclipse occurs about every 18 months somewhere on Earth, although at any particular location, it happens much less often.

The total eclipse on Aug. 21, 2017, will be visible within a 70-mile-wide path that will cross 14 states in the continental U.S. from Oregon to South Carolina. Along this path of totality, the umbra, or dark inner shadow, of the moon will travel at speeds of almost 3,000 miles per hour in western Oregon to 1,500 miles per hour in South Carolina.

In eclipse maps, the umbra is often depicted as a dark circle or oval racing across the landscape. But a detailed visualization created for this year's eclipse reveals that the shape is more like an irregular polygon with slightly curved edges, and it changes as the shadow moves along the path of totality.

"With this new visualization, we can represent the umbral shadow with more accuracy by accounting for the influence of elevation at different points on Earth, as well as the way light rays stream through lunar valleys along the moon's ragged edge," said NASA visualizer Ernie Wright at Goddard.

This unprecedented level of detail was achieved by coupling 3-D mapping of the moon's surface, done by NASA's Lunar Reconnaissance Orbiter, or LRO, with Earth elevation information from several datasets.

LRO's mapping of the lunar terrain also makes it possible to predict very accurately when and where the brilliant flashes of light called Baily's Beads or the diamond-ring effect will occur. These intense spots appear along the edge of the darkened disk just before totality, and again just afterward, produced by sunlight peeking through valleys along the uneven rim of the moon.

In the very distant future, the spectacular shows put on by total solar eclipses will cease. That's because the moon is, on average, slowly receding from Earth at a rate of about 1-1/2 inches, or 4 centimeters, per year. Once the moon moves far enough away, its apparent size in the sky will be too small to cover the sun completely.

Read more at Science Daily

North American monsoon storms fewer but more extreme

Monsoon season now brings more extreme wind and rain to central and southwestern Arizona than in the past, according to new research led by the University of Arizona.

Although there are now fewer storms, the largest monsoon thunderstorms bring heavier rain and stronger winds than did the monsoon storms of 60 years ago, the scientists report.

"The monsoon is the main severe weather threat in Arizona. Dust storms, wind, flash flooding, microbursts -- those are the things that are immediate dangers to life and property," said co-author Christopher Castro, a UA associate professor of hydrology and atmospheric sciences.

The researchers compared precipitation records from 1950-1970 to those from 1991-2010 for Arizona. The researchers also used those records to verify that their climate model generated realistic results.

"This is one of the first studies to look at long-term changes in monsoon precipitation," Castro said. "We documented that the increases in extreme precipitation are geographically focused south and west of the Mogollon Rim -- and that includes Phoenix."

The region of Arizona with more extreme storms includes Bullhead City, Kingman, the Phoenix metropolitan area, the Colorado River valley and Arizona's low deserts, including the towns of Casa Grande, Gila Bend, Ajo, Lukeville and Yuma.

The Tohono O'odham Reservation, Luke Air Force Base, the Barry Goldwater Air Force Range and the Yuma Proving Ground are also in the region with more extreme monsoon weather.

Tucson is just outside of the zone with more extreme storms.

Having less frequent but more intense storms is consistent with what is expected throughout the world due to climate change, Castro said.

"Our work shows that it certainly holds true for the monsoon in Arizona," he said.

When the researchers compared the results from climate and weather models to the actual observations, the model with a resolution of less than 1.5 miles (2.5 km) accurately reproduced the precipitation data. The models with resolutions of 10 miles or more did not.

"You just can't trust coarser simulations to represent changes in severe weather. You have to use the high-resolution model," Castro said.

First author Thang M. Luong conducted the research as part of his doctoral work at the UA. He is now a postdoctoral researcher at King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.

The paper, "The More Extreme Nature of North American Monsoon Precipitation in the Southwestern U.S. as Revealed by a Historical Climatology of Simulated Severe Weather Events," by Luong, Castro, Hsin-I Chang and Timothy Lahmers of the UA Department of Hydrology and Atmospheric Sciences and David K. Adams and Carlos A. Ochoa-Moya of the Universidad Nacional Autónoma de México, México D.F. was published July 3 in the early online edition of the Journal of Applied Meteorology and Climatology.

The U.S. Department of Defense Strategic Environmental Research and Development Program and the Universidad Nacional Autónoma de México PAPIIT funded the research.

The researchers wanted to identify risks from warm-season extreme weather, especially those to Department of Defense installations in the American Southwest.

Existing global and regional climate change models don't represent the North American monsoon well in either seasonal forecasts or climate projections, the research team wrote.

Looking at the average precipitation over the entire monsoon season doesn't show whether monsoon storms are becoming more severe now compared with 60 years ago, Castro said.

Therefore Luong, Castro and their colleagues looked for extreme rainfall events during 1950-1970 as compared with 1991-2010. Average precipitation was about the same, but 1991-2011 had more storms with very heavy rain.

"What's going on in the changes to the extremes is very different from what goes on in the changes to the mean," Castro said. "Big storms, heavy flooding -- we found out those types of extreme precipitation events are becoming more intense and are becoming more intense downwind of the mountain ranges."

The team tested a common computer model of the atmosphere to try to replicate the historical changes in monsoon storm intensity. The model, similar to one used by the National Weather Service for forecasts, produces results similar to what would be observed on radar or satellite imagery by realistically simulating the physical structure of monsoon thunderstorms.

A key innovation of the UA research was the level of detail -- the team tested several different levels of resolution. Only by using the high resolution of 1.5 miles (2.5 km) could the model replicate the actual rainfall recorded for the two 20-year periods being compared.

The recorded data showed only rainfall. The high-resolution models indicated rainier monsoon storms were accompanied by higher winds and more downbursts.

"Because the models get the precipitation right, it gives us confidence that the models get the winds right too," Castro said.

He said that in Phoenix, monsoon storms used to be late in the evening but are now happening earlier.

Read more at Science Daily

In saliva, clues to a 'ghost' species of ancient human

Neanderthal. In saliva, scientists have found hints that a "ghost" species of archaic human may have contributed genetic material to ancestors of people living in Sub-Saharan Africa today.

In saliva, scientists have found hints that a "ghost" species of archaic humans may have contributed genetic material to ancestors of people living in Sub-Saharan Africa today.

The research adds to a growing body of evidence suggesting that sexual rendezvous between different archaic human species may not have been unusual.

Past studies have concluded that the forebears of modern humans in Asia and Europe interbred with other early hominin species, including Neanderthals and Denisovans. The new research is among more recent genetic analyses indicating that ancient Africans also had trysts with other early hominins.

"It seems that interbreeding between different early hominin species is not the exception -- it's the norm," says Omer Gokcumen, PhD, an assistant professor of biological sciences in the University at Buffalo College of Arts and Sciences.

"Our research traced the evolution of an important mucin protein called MUC7 that is found in saliva," he says. "When we looked at the history of the gene that codes for the protein, we see the signature of archaic admixture in modern day Sub-Saharan African populations."

The research was published on July 21 in the journal Molecular Biology and Evolution. The study was led by Gokcumen and Stefan Ruhl, DDS, PhD, a professor of oral biology in UB's School of Dental Medicine.

A tantalizing clue in saliva

The scientists came upon their findings while researching the purpose and origins of the MUC7 protein, which helps give spit its slimy consistency and binds to microbes, potentially helping to rid the body of disease-causing bacteria.

As part of this investigation, the team examined the MUC7 gene in more than 2,500 modern human genomes. The analysis yielded a surprise: A group of genomes from Sub-Saharan Africa had a version of the gene that was wildly different from versions found in other modern humans.

The Sub-Saharan variant was so distinctive that Neanderthal and Denisovan MUC7 genes matched more closely with those of other modern humans than the Sub-Saharan outlier did.

"Based on our analysis, the most plausible explanation for this extreme variation is archaic introgression -- the introduction of genetic material from a 'ghost' species of ancient hominins," Gokcumen says. "This unknown human relative could be a species that has been discovered, such as a subspecies of Homo erectus, or an undiscovered hominin. We call it a 'ghost' species because we don't have the fossils."

Given the rate that genes mutate during the course of evolution, the team calculated that the ancestors of people who carry the Sub-Saharan MUC7 variant interbred with another ancient human species as recently as 150,000 years ago, after the two species' evolutionary path diverged from each other some 1.5 to 2 million years ago.

Why MUC7 matters

The scientists were interested in MUC7 because in a previous study they showed that the protein likely evolved to serve an important purpose in humans.

In some people, the gene that codes for MUC7 holds six copies of genetic instructions that direct the body to build parts of the corresponding protein. In other people, the gene harbors only five sets of these instructions (known as tandem repeats).

Prior studies by other researchers found that the five-copy version of the gene protected against asthma, but Gokcumen and Ruhl did not see this association when they ran a more detailed analysis.

The new study did conclude, however, that MUC7 appears to influence the makeup of the oral microbiome, the collection of bacteria within the mouth. The evidence for this came from an analysis of biological samples from 130 people, which found that different versions of the MUC7 gene were strongly associated with different oral microbiome compositions.

Read more at Science Daily

Best measure of star-forming material in galaxy clusters in early universe

The Tadpole Galaxy is a disrupted spiral galaxy showing streams of gas stripped by gravitational interaction with another galaxy. Molecular gas is the required ingredient to form stars in galaxies in the early universe.

The international Spitzer Adaptation of the Red-sequence Cluster Survey (SpARCS) collaboration based at the University of California, Riverside has combined observations from several of the world's most powerful telescopes to carry out one of the largest studies yet of molecular gas -- the raw material which fuels star formation throughout the universe -- in three of the most distant clusters of galaxies ever found, detected as they appeared when the universe was only four billion years old.

Results were recently published in The Astrophysical Journal Letters. Allison Noble, a postdoctoral researcher at the Massachusetts Institute of Technology, led this newest research from the SpARCS collaboration.

Clusters are rare regions of the universe consisting of tight groups of hundreds of galaxies containing trillions of stars, as well as hot gas and mysterious dark matter. First, the research team used spectroscopic observations from the W. M. Keck Observatory on Mauna Kea, Hawai'i, and the Very Large Telescope in Chile that confirmed 11 galaxies were star-forming members of the three massive clusters. Next, the researchers took images through multiple filters from NASA's Hubble Space Telescope, which revealed a surprising diversity in the galaxies' appearance, with some galaxies having already formed large disks with spiral arms.

One of the telescopes the SpARCS scientists used is the extremely sensitive Atacama Large Millimeter Array (ALMA) telescope capable of directly detecting radio waves emitted from the molecular gas found in galaxies in the early universe. ALMA observations allowed the scientists to determine the amount of molecular gas in each galaxy, and provided the best measurement yet of how much fuel was available to form stars.

The researchers compared the properties of galaxies in these clusters with the properties of "field galaxies" (galaxies found in more typical environments with fewer close neighbors). To their surprise, they discovered that cluster galaxies had higher amounts of molecular gas relative to the amount of stars in the galaxy, compared to field galaxies. The finding puzzled the team because it has long been known that when a galaxy falls into a cluster, interactions with other cluster galaxies and hot gas accelerate the shut off of its star formation relative to that of a similar field galaxy (the process is known as environmental quenching).

"This is definitely an intriguing result," said Gillian Wilson, a professor of physics and astronomy at UC Riverside and the leader of the SpARCS collaboration. "If cluster galaxies have more fuel available to them, you might expect them to be forming more stars than field galaxies, and yet they are not."

Noble, a SpARCS collaborator and the study's leader, suggests several possible explanations: It is possible that something about being in the hot, harsh cluster environment surrounded by many neighboring galaxies perturbs the molecular gas in cluster galaxies such that a smaller fraction of that gas actively forms stars. Alternatively, it is possible that an environmental process, such as increased merging activity in cluster galaxies, results in the observed differences between the cluster and field galaxy populations.

"While the current study does not answer the question of which physical process is primarily responsible for causing the higher amounts of molecular gas, it provides the most accurate measurement yet of how much molecular gas exists in galaxies in clusters in the early universe," Wilson said.

Read more at Science Daily

A wolf's howl in miniature: Researchers discover mice speak similarly to humans

Some mice and rats employ a whistle-like mechanism.

Grasshopper mice (genus Onychomys), rodents known for their remarkably loud call, produce audible vocalizations in the same way that humans speak and wolves howl, according to new research published in Proceedings of the Royal Society B. Grasshopper mice employ both a traditional whistle-like mechanism used by other mice and rats and a unique airflow-induced tissue vibration like that of humans.

Researchers from Northern Arizona University, Midwestern University at Glendale and Ritsumeikan University in Japan used heliox experiments, laryngeal and vocal tract morphological investigations and biomechanical modelling to investigate how grasshopper mice produce spectacular long-distance calls.

"Our findings provide the first evidence of a mouse that produces sound like humans and sets the stage for studies on vocal injuries and aging," said lead author Bret Pasch, NAU assistant professor and Merriam-Powell Center affiliate. "Moreover, the research provides a baseline for a larger comparative analysis of vocalizations in rodents, which comprise more than 40 percent of mammalian diversity but whose many voices remain undiscovered."

Grasshopper mice are predatory rodents that inhabit deserts, grasslands and prairies of the western United States and northern Mexico. Like most mice, grasshopper mice produce ultrasonic vocalizations above the range of human hearing in close-distance social interactions through whistle-like mechanisms.

Unlike other mice, grasshopper mice also produce long-distance audible vocalizations, or advertisement vocalizations. Naturalist Vernon Bailey described the call of grasshopper mice as a "wolf's howl in miniature." Both male and female animals often assume an upright posture and open their mouths widely to generate a loud call that may carry more than 100 meters. Grasshopper mice have relatively large home ranges, so their calls serve as a mechanism to detect mates and competitors across large distances.

Imaging the voice box of grasshopper mice revealed a thin layer of connective tissue and a tiny structure called a vocal membrane previously only described in detail in echolocating bats. In addition, the mice possess a bell-shaped vocal tract, similar in shape to a loudspeaker, which increases vocal intensity, just like opera singers.

From Science Daily

New Kingdom Egypt: The goldsmith’s tomb

A view of the ruins of the town of Sai. Founded by the Egyptians on the island of the same name in the Nile, in what is now Sudan, the town was occupied from 1500 until 1200 BC.

Ludwig-Maximilians-Universitaet (LMU) in Munich Egyptologist Julia Budka is studying the impact of intercultural contacts in Ancient Egypt. Her excavations in Sudan have uncovered a tomb dating to around 1450 BC on the island of Sai in the Nile.

A previously unknown tomb, some 3400 years old, has recently been uncovered on the island of Sai in the River Nile. It was in use for some time and contains the remains of up to 25 persons. Further analysis of the finds could elucidate the multicultural nature of the island's population during this period.

The island was then located in Nubia, which was the primary source of gold for the New Kingdom of the Egyptian Pharaohs at that time. The tomb was most probably built for a master goldsmith by the name of Khnummose, and was discovered during excavations conducted by Julia Budka, Professor of Egyptian Archaeology and Art. Investigation of the tomb's contents and inscriptions has so far revealed that, following the conquest by the Pharaoh Thutmose III of the local African Kerma kingdom of Kerma, the local elites were rapidly integrated by the new regime. The earliest Egyptian-style burials on Sai date to the reign of this king.

Over the past 5 years, Budka has carried out parallel studies on three different Egyptian settlements that were established during the period of the so-called New Kingdom between 1500 und 1200 BC. The excavations on the island of Sai, which lies in what is now the Sudanese section of the Nile, not only provide insights into the relationship between the official representatives of the occupying power and the local Nubian population, they also demonstrate that the island was inhabited for longer than hitherto assumed.

"It had been thought that the settlement on the island was abandoned after the foundation of a new town at Amara West. Our finds, on the other hand, prove that Hornakht, one of Egypt's highest ranking bureaucrats during the reign of Ramses II, not only had his official residence on the island, but was also buried there," says Budka. This clearly shows that the town on Sai survived until about 1200 BC.

From Science Daily