Scientists actually published a map of the C. elegans nervous system back in 1986. The work involved analyzing neural structures on thousands of images and manually connecting the dots, creating a web of around 5,000 connections between the structures on one image and another. This work was critical in making the worm a popular model for studying human biology, but the map wasn't overly detailed, only describing the nervous system of the female worm and leaving out large sections of the body.
Fast-forward a few decades and scientists have now filled in the blanks. Led by Scott Emmons, a professor of genetics at Albert Einstein College of Medicine, the researchers combined these older roundworm images with new ones and then employed purpose-built software to stitch them together, forming complete wiring diagrams for both sexes of C. elegans. These include all the connections between the neurons and the worm's muscles, tissues like the gut and skin, and the synapses between the muscle cells.
"It was simply digital imaging," Emmons explains to New Atlas. "A digital camera on the electron microscope, digital scanners for the old prints and the PC, which weren't available to the original mappers in the 1970s. The new connectomes are now in digital format."
The early surveys of these maps reveal some interesting insights. For example, Emmons says the synaptic pathways between the two sexes are similar, but they observed differences in the strength of some, particularly those related to reproductive functions in the female and those related to copulation in the male.
The researchers describe this achievement as a major milestone in the field of connectomics, as it is known, and say the complete diagram can serve as a starting point for further exploration of how these neural connections control the worm's behavior. And because of the molecules it shares with the human nervous system, it could help us better understand that and possibly even uncover new therapeutic treatments for some neurological conditions further down the track.
When the tension rises, unexpected things can happen – not least when it comes to gold atoms. Researchers from, among others, Chalmers University of Technology, have now managed, for the first time, to make the surface of a gold object melt at room temperature.
Ludvig de Knoop, from Chalmers’ Department of Physics, placed a small piece of gold in an electron microscope. Observing it at the highest level of magnification and increasing the electric field step-by-step to extremely high levels, he was interested to see how it influenced the gold atoms. It was when he studied the atoms in the recordings from the microscope, that he saw something exciting. The surface layers of gold had actually melted – at room temperature.
"I was really stunned by the discovery. This is an extraordinary phenomenon, and it gives us new, foundational knowledge of gold,” says Ludvig de Knoop. What happened was that the gold atoms became excited. Under the influence of the electric field, they suddenly lost their ordered structure and released almost all their connections to each other. Upon further experimentation, the researchers discovered that it was also possible to switch between a solid and a molten structure.
The discovery of how gold atoms can lose their structure in this way is not just spectacular, but also groundbreaking scientifically. Together with the theoretician Mikael Juhani Kuisma, from the University of Jyväskylä in Finland, Ludvig de Knoop and colleagues have opened up new avenues in materials science. The results are now published in the journal Physical Review Materials.
A new imaging tool promises to open the door to all sorts of new insights about the brain and how it works. The tool lets scientists see each of the human brain's 100 trillion synapses and 100 billion neurons, individually, plus all other cellular objects and many of their sub-cellular components.
The human brain contains more synapses than there are galaxies in the observable universe (to put a number on it, there are perhaps 100 trillion synapses versus 100 billion galaxies), and now scientists can see them all – individually. A new imaging tool promises to open the door to all sorts of new insights about the brain and how it works. The tool can generate images at a nanoscale resolution, which is small enough to see all cellular objects and many of their sub-cellular components (so for the biology-literate, that's stuff like neurons and the synapses that permit them to fire, plus axons, dendrites, glia, mitochondria, blood vessel cells, and so on).
Developed by researchers at the Boston University School of Medicine and Harvard University, the imaging method employs an automated tape-collecting device equipped with a diamond knife to obtain ultra-thin brain sections, which are then scanned under an electron microscope. Different colors are used to identify different cellular objects using software developed by study co-author Daniel Berger.
To demonstrate their new tool the researchers peered inside the brain of an adult mouse. They imaged a very small piece of a mouse's neocortex at a resolution that made individual synaptic vesicles visible (these are tiny spheres of less than 40 nm diameter that store neurotransmitters, or chemical signals, for release from a synapse into a "target" neuron). The specific area they imaged is involved in receiving sensory information from mouse whiskers, which are much more sensitive than human fingertips.
When you look at a photograph of a cat, chances are that you can recognize the pictured animal whether it’s ginger or striped — or whether the image is black and white, speckled, worn or faded. You can probably also spot the pet when it’s shown curled up behind a pillow or leaping onto a countertop in a blur of motion. You have naturally learned to identify a cat in almost any situation. In contrast, machine vision systems powered by deep neural networks can sometimes even outperform humans at recognizing a cat under fixed conditions, but images that are even a little novel, noisy or grainy can throw off those systems completely.
A research team in Germany has now discovered an unexpected reason why: While humans pay attention to the shapes of pictured objects, deep learning computer vision algorithms routinely latch on to the objects’ textures instead. This finding, presented at the International Conference on Learning Representations in May, highlights the sharp contrast between how humans and machines “think,” and illustrates how misleading our intuitions can be about what makes artificial intelligences tick. It may also hint at why our own vision evolved the way it did.
Cats With Elephant Skin and Planes Made of Clocks
Deep learning algorithms work by, say, presenting a neural network with thousands of images that either contain or do not contain cats. The system finds patterns in that data, which it then uses to decide how best to label an image it has never seen before. The network’s architecture is modeled loosely on that of the human visual system, in that its connected layers let it extract increasingly abstract features from the image. But the system makes the associations that lead it to the right answer through a black-box process that humans can only try to interpret after the fact. “We’ve been trying to figure out what leads to the success of these deep learning computer vision algorithms, and what leads to their brittleness,” said Thomas Dietterich, a computer scientist at Oregon State University who was not involved in the new study.
A collaboration of Chinese and Japanese astrophysicists has reported the highest energy photons ever seen: gamma rays with energies up to 450 trillion electron volts (TeV).
The particles of light were traced back to the Crab nebula, the remnant of a stellar explosion observed by Chinese astronomers nearly 1000 years ago, and the powerful pulsar, a dense neutron star, that now sits at the nebula’s heart. “We know the environment of a pulsar is extreme,” says Geraint Lewis, an astrophysicist at the University of Sydney in Australia who was not involved in the research. The question raised by the finding “is just how extreme,” he says. He says the results will help constrain ideas about how the photons are boosted to such extraordinary energies.
The Tibet ASgamma experiment spotted the photons using an array of nearly 600 scintillation detectors, sensors that turn particle strikes into electronic signals. The detectors are spread out across 66,000 square meters in a valley 4300 meters above sea level on the Tibetan Plateau in China. When gamma rays strike Earth’s atmosphere they create air showers—spreading cascades of electrons and other subatomic particles. As these particles hit the detectors, the timing and energy of the strikes are recorded—enabling astronomers to reconstruct the energy and trajectory of the original gamma ray.
The UCLA-developed sensors work at room temperature, unlike current technology that needs extreme cold.
Researchers at the UCLA Samueli School of Engineering have developed an ultra-sensitive light-detecting system that could enable astronomers to view galaxies, stars and planetary systems in superb detail. The system works at room temperature — an improvement over similar technology that only works in temperatures nearing 270 degrees below zero Celsius, or minus 454 degrees Fahrenheit. A paper detailing the advance is published today in Nature Astronomy.
The sensor system detects radiation in the terahertz band of the electromagnetic spectrum, which includes parts of the far-infrared and microwave frequencies. The system produces images in ultra-high clarity, and it can detect terahertz waves across a broad spectral range — an improvement of at least 10 times more than current technologies that only detect such waves in a narrow spectral range. Its broad range capabilities could allow it to do observations that currently require several different instruments. It identifies what elements and molecules — for example, water, oxygen, carbon monoxide and other organic molecules, are present in those regions of space by seeing if their individual telltale spectral signatures are present.
“Looking in terahertz frequencies allows us to see details that we can’t see in other parts of the spectrum,” said Mona Jarrahi, a UCLA professor of electrical and computer engineering who led the research. “In astronomy, the advantage of the terahertz range is that, unlike infrared and visible light, terahertz waves are not obscured by interstellar gas and dust that surround these astronomical structures.”
The technology could be especially effective in space-based observatories, Jarrahi said, because unlike on Earth, terahertz waves can be detected without interference from the atmosphere.
Astronomers have spotted a distant pair of titanic black holes headed for a collision.
Each black hole's mass is more than 800 million times that of our sun. As the two gradually draw closer together in a death spiral, they will begin sending gravitational waves rippling through space-time. Those cosmic ripples will join the as-yet-undetected background noise of gravitational waves from other supermassive black holes. Even before the destined collision, the gravitational waves emanating from the supermassive black hole pair will dwarf those previously detected from the mergers of much smaller black holes and neutron stars.
"Supermassive black hole binaries produce the loudest gravitational waves in the universe," says co-discoverer Chiara Mingarelli, an associate research scientist at the Flatiron Institute's Center for Computational Astrophysics in New York City.
Gravitational waves from supermassive black hole pairs "are a million times louder than those detected by LIGO."
Two researchers — Robert McIntyre, an MIT graduate, and Gregory M. Fahy, PhD., 21st Century Medicine (21CM) Chief Scientific Officer, have developed a method for scanning a preserved brain’s connectome (the 150 trillion microscopic synaptic connections presumed to encode all of a person’s knowledge). That data could possibly be used, centuries later, to reconstruct a whole-brain emulation — uploading your mind into a computer or Avatar-style robotic, virtual, or synthetic body, McIntyre and others suggest.
According to MIT Technology Review, McIntyre has formed a startup company called Nectome that has won a large NIH grant for creating “technologies to enable whole-brain nanoscale preservation and imaging.” McIntyre is also collaborating with Edward Boyden, PhD., a top neuroscientist at MIT and inventor of a new “expansion microscopy” technique (to achieve super-resolution with ordinary confocal microscopes), as KurzweilAIreported. The technique also causes brain tissue to swell, making it more accessible.
Preserving brain information patterns, not biological function
Unlike cryonics (freezing people or heads for future revival), the researchers did not intend to revive a pig or pig brain (or human, in the future). Instead, the idea is to develop a bridge to future mind-uploading technology by preserving the information content of the brain, as encoded within the frozen connectome.
The first step in the ASC procedure is to perfuse the brain’s vascular system with the toxic fixative glutaraldehyde (typically used as an embalming fluid but also used by neuroscientists to prepare brain tissue for the highest resolution electron microscopic and immunofluorescent examination). That instantly halts metabolic processes by covalently crosslinking the brain’s proteins in place, leading to death (by contemporary standards). The brain is then quickly stored at -130 degrees C, stopping all further decay.
Researchers report ultraprecise imaging of a postmortem human brain.
Over 100 hours of scanning has yielded a 3-D picture of the whole human brain that’s more detailed than ever before. The new view, enabled by a powerful MRI, has the resolution potentially to spot objects that are smaller than 0.1 millimeters wide. “We haven’t seen an entire brain like this,” says electrical engineer Priti Balchandani of the Icahn School of Medicine at Mount Sinai in New York City, who was not involved in the study. “It’s definitely unprecedented.”
The scan shows brain structures such as the amygdala in vivid detail, a picture that might lead to a deeper understanding of how subtle changes in anatomy could relate to disorders such as post-traumatic stress disorder.
To get this new look, researchers at Massachusetts General Hospital in Boston and elsewhere studied a brain from a 58-year-old woman who died of viral pneumonia. Her donated brain, presumed to be healthy, was preserved and stored for nearly three years.
Before the scan began, researchers built a custom spheroid case of urethane that held the brain still and allowed interfering air bubbles to escape. Sturdily encased, the brain then went into a powerful MRI machine called a 7 Tesla, or 7T, and stayed there for almost five days of scanning.
The strength of the 7T, the length of the scanning time and the fact that the brain was perfectly still led to the high-resolution images, which are described May 31 at bioRxiv.org. Associated videos of the brain, as well as the underlying dataset, are publicly available.
Demis Hassabis will discuss the capabilities and power of self-learning systems. He will illustrate this with reference to some of DeepMind's recent breakthroughs, including the AlphaZero, AlphaStar and AlphaFold systems, and talk about the implications of cutting-edge AI research for scientific and philosophical discovery.
NASA’s Transiting Exoplanet Survey Satellite (TESS) has discovered a world between the sizes of Mars and Earth orbiting a bright, cool, nearby star. The planet, called L 98-59b, marks the tiniest discovered by TESS to date.
Two other worlds orbit the same star. While all three planets' sizes are known, further study with other telescopes will be needed to determine if they have atmospheres and, if so, which gases are present. The L 98-59 worlds nearly double the number of small exoplanets -- that is, planets beyond our solar system -- that have the best potential for this kind of follow-up.
"The discovery is a great engineering and scientific accomplishment for TESS," said Veselin Kostov, an astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, and the SETI Institute in Mountain View, California. "For atmospheric studies of small planets, you need short orbits around bright stars, but such planets are difficult to detect. This system has the potential for fascinating future studies."
A paper on the findings, led by Kostov, was published in the June 27 issue of The Astronomical Journal. L 98-59b is around 80% Earth's size and about 10% smaller than the previous record holder discovered by TESS. Its host star, L 98-59, is an M dwarf about one-third the mass of the Sun and lies about 35 light-years away in the southern constellation Volans. While L 98-59b is a record for TESS, even smaller planets have been discovered in data collected by NASA's Kepler satellite, including Kepler-37b, which is only 20% larger than the Moon.
The two other worlds in the system, L 98-59c and L 98-59d, are respectively around 1.4 and 1.6 times Earth's size. All three were discovered by TESS using transits, periodic dips in the star's brightness caused when each planet passes in front of it. TESS monitors one 24-by-96-degree region of the sky, called a sector, for 27 days at a time. When the satellite finishes its first year of observations in July, the L 98-59 system will have appeared in seven of the 13 sectors that make up the southern sky.
Kostov's team hopes this will allow scientists to refine what's known about the three confirmed planets and search for additional worlds. "If you have more than one planet orbiting in a system, they can gravitationally interact with each other," said Jonathan Brande, a co-author and astrophysicist at Goddard and the University of Maryland, College Park. "TESS will observe L 98-59 in enough sectors that it may be able to detect planets with orbits around 100 days. But if we get really lucky, we might see the gravitational effects of undiscovered planets on the ones we currently know."
M dwarfs like L 98-59 account for three-quarters of our Milky Way galaxy's stellar population. But they are no larger than about half the Sun's mass and are much cooler, with surface temperatures less than 70% of the Sun's. Other examples include TRAPPIST-1, which hosts a system of seven Earth-size planets, and Proxima Centauri, our nearest stellar neighbor, which has one confirmed planet. Because these small, cool stars are so common, scientists want to learn more about the planetary systems that form around them.
L 98-59b, the innermost world, orbits every 2.25 days, staying so close to the star it receives as much as 22 times the amount of energy Earth receives from the Sun. The middle planet, L 98-59c, orbits every 3.7 days and experiences about 11 times as much radiation as Earth. L 98-59d, the farthest planet identified in the system so far, orbits every 7.5 days and is blasted with around four times the radiant energy as Earth.
Researchers trap 111 neutral atoms in a predefined, defect-free motif using a new method that could, in the foreseeable future, control one million such atoms.
Neutral atoms trapped in an array of optical traps can act as qubits for quantum computing applications. But first, researchers need to accurately position the atoms within the array to create defect-free patterns that they can then manipulate and use for calculations. In 2018, researchers arranged 72 atoms in various motifs, including a knot and a cube. Now Gerhard Birkl and colleagues at the Technical University of Darmstadt in Germany demonstrate a new method for patterning atoms that takes that number to a record 111. They say that their method should be easily scalable, potentially to one million atoms or more.
Birkl and colleagues cooled a cloud of rubidium atoms to 100 ��K. They then loaded the atoms into a microtrap array—hundreds of laser traps arranged in a square lattice that they created by directing a laser beam through an array of microlenses. Initially each trap contained a few atoms. To reduce this number to one, the team used a technique called collisional blockade to remove pairs of atoms from each site. Sites that initially housed an odd number of atoms were left with exactly one. Those with an even number ended up with zero. The team then moved single atoms to any empty site in their target pattern using laser tweezers.
Using their method, the team created a 10-by-10-atom square, a checkerboard made of 105 atoms, and two interconnected squares that contained 111 atoms. They are now working on patterns containing 1000 atoms. Birkl says that the only roadblock to arranging larger numbers of atoms is financial—to create more trap sites, they will need to purchase more powerful lasers.
If astronomers want to learn about how supermassive black holes form, they have to start small—really small, astronomically speaking. In fact, a team including University of Michigan astronomer Elena Gallo has discovered that a black hole at the center of a nearby dwarf galaxy, called NGC 4395, is about 40 times smaller than previously thought. Their findings are published in the journal Nature Astronomy.
Currently, astronomers believe that supermassive black holes sit at the center of every galaxy as massive as or larger than the Milky Way. But they’re curious about black holes in smaller galaxies such as NGC 4395 as well. Knowing the mass of the black hole at the center of NGC 4395—and being able to measure it accurately—can help astronomers apply these techniques to other black holes.
“The question remains open for small or dwarf galaxies: Do these galaxies have black holes, and if they do, do they scale the same way as supermassive black holes?” Elena Gallo, Associate Professor of Astronomy said. “Answering these questions might help us understand the very mechanism through which these monster black holes were assembled when the universe was in its infancy.”
To determine the mass of NGC’s black hole, Gallo and her fellow researchers employed reverberation mapping. This technique measures mass by monitoring radiation thrown off by what’s called an accretion disk around the black hole. An accretion disk is a mass of matter collected by the gravitational pull of black holes.
As radiation travels outward from this accretion disk, it passes through another cloud of material farther out from the black hole that’s more diffuse than the accretion disk. This area is called the broad-line region.
When the radiation hits gas in the broad-line region, it causes atoms in it to undergo a transition. This means that the radiation bumps an electron out of the shell of an atom of hydrogen, for example, causing the atom to occupy a more energetic level of the atom. After the radiation passes, the atom settles back into its previous state. Astronomers can image this transition, which looks like a flash of brightness.
A new study has revealed the role that regular bugs play in spreading superbugs. A team from Aston University examined almost 20,000 insects collected from National Health Service (NHS) hospitals across the United Kingdom, and studied the kinds of bacteria they were carrying. The vast majority were found to host potentially harmful bacteria, more than half of which were resistant to some kinds of antibiotics.
The researchers began by collecting 19,937 individual insects from seven UK hospitals between March 2010 and August 2011, with about 75 percent of the final haul comprised of flies, 14 percent being "true bugs" like aphids, and the rest made up of ants, wasps, bees and moths. These were caught using UV light flytraps, bug zappers and sticky flypaper, placed throughout the facilities in wards, neonatal and maternity units, and food preparation areas.
Then, the team conducted microbiological analyses to determine the types and levels of bacteria the insects harbored, both in and on their bodies. Almost 90 percent of the insects tested were found to be carrying bacteria that can be harmful, and in some cases the levels were high enough to potentially cause infection in humans.
From those insects, the researchers isolated 86 different strains of bacteria, with the most common family being Enterobacteriaceae, which includes E. coli and Salmonella, at 41 percent. The second most common was the Bacillus family, which includes known food poison-associated bacteria like B. cereus, at 24 percent, and then the Staph family at 19 percent. The study showed that 53 percent of these bacterial strains were resistant to at least one class of antibiotics, with 19 percent showing multi-drug resistance.
Rising temperatures as a result of climate change are already exposing people to health risks across the globe, according to a new report from 27 global institutions co-led by UCL researchers.
Outdoor workers, people with underlying health conditions and the urban elderly are especially at risk, according to the findings published today in The Lancet.
“Exposure and vulnerability to extreme heat is unacceptably high and rising for people all around the world. Heat stress is hitting hard. In high temperatures, outdoor work, especially in agriculture, is hazardous,” said Professor Hugh Montgomery, (UCL Medicine), Co-Chair of the Lancet Countdown and Director of the UCL Institute for Human Health and Performance.
“Areas from Northern England and California, to Australia are seeing savage fires with direct deaths, displacement and loss of housing as well as respiratory impacts from smoke inhalation.” Leading doctors, academics and policy professionals from 27 organizations have contributed analysis and jointly authored the report. As members of The Lancet Countdown: Tracking Progress on Health and Climate Change, partners behind the research include the World Bank, World Health Organization (WHO), UCL and Tsinghua University, among others.
The report investigated the impact of climate change on health in 478 cities across the globe, identifying health impacts including:
157 million more vulnerable people were subjected to a heatwave last year than in 2000, and 18 million more than in 2016.
153 billion hours of work were lost in 2017 due to extreme heat as a result of climate change. China alone lost 21 billion hours, the equivalent of a year’s work for 1.4% of their working population. New methodologies have captured this data for the first time.
Rising ambient temperatures are placing vulnerable populations at increased risks across all regions of the world. Europe and the East Mediterranean are particularly at risk, markedly more so than in Africa and Southeast Asia, most likely due to ageing populations living in cities, with 42% and 43% of people over 65 vulnerable to heat exposure.
The report highlights that heat greatly exacerbates urban air pollution, with 97% of cities in low- and middle- income countries not meeting WHO air quality guidelines.
Heat stress, an early and severe effect of climate change, is commonplace and people, and the health systems we rely on, are ill equipped to cope.
Rising temperatures and unseasonable warmth is responsible for cholera and dengue fever spreading, with vectorial capacity for their transmission increasing across many endemic areas.
The mean global temperature change to which humans are exposed is more than double the global average change, with temperatures rising 0.8°C in inhabited areas versus 0.3°C.
By guiding evolution, scientists have managed to manipulate micro-organisms into producing useful new drugs and materials, but it’s a time-consuming process. Now, UNC researchers have developed a new tool that speeds up the process in mammalian cells, creating new therapeutics in a matter of days.
The new system has been dubbed VEGAS, which stands for Viral Evolution of Genetically Actuating Sequences. It's based around the Sindbis virus, because of its ability to quickly spread and mutate. The team introduce the virus into a culture dish of cells, and try to guide it to mutate so that it can perform a specific function in those mammalian cells – say, switch on certain genes or activate a protein. The scientists then tune the environment to conditions that allow only those desired mutant genes to thrive.
In their experiments, the UNC researchers started by focusing on a protein called a tetracycline transactivator (tTA), a protein that activates genes and is a common subject in these kinds of tests.
Certain antibiotics, such as doxycycline, usually prevent this protein from working, so the researchers tested the VEGAS system by trying to direct tTA to evolve a resistance to these antibiotics. And sure enough, the team managed to create a new version of tTA with 22 mutations that allowed it to keep working, even with high levels of doxycycline. Best of all, they managed to create this in just seven days.
"To get a sense of how efficient that is, consider that a previously reported mammalian directed evolution method applied to the tetracycline transactivator took four months to yield just two mutations that conferred only partial insensitivity to doxycycline," says Justin English, lead author of the study.
For the next experiment, the researchers used the system to explore a poorly-understood cellular receptor called MRGPRX2. They evolved it so that it was always active, and in the process learned more about how it worked. That in turn let them quickly evolve nanobodies that could target these kinds of receptors, which could lead to a range of potential new treatments.
Salvador Jorgensen has spent more than 15 years studying great white sharks near California's coast. The senior research scientist from the Monterey Bay Aquarium and his team have attached tracking tags to 165 of the toothy predators, which routinely visit islands west of San Francisco and prey on elephant seals. But something odd happened one autumn: “In 2009, 17 of those tagged white sharks were simultaneously swimming around the Farallon Islands, when they abruptly departed. Not just one or two but all 17, in a matter of hours,” Jorgensen recalls. “Normally the sharks hang around for weeks or months at a time.” So why did they flee? Great white sharks are perhaps the most widely feared predators in the ocean, but it turns out they may have something to fear, too: orcas, also known as killer whales.
Jorgensen and his colleagues drew this conclusion in a recent study that combined their shark-tagging data with a nearly three-decade survey of wildlife abundance around Southeast Farallon Island. Great whites have been seen abandoning this prime feeding area when killer whales come too close for comfort—even if the mammals are simply passing through for a few hours. And the sharks do not just disappear for a day or two—they stay away for the entire season. Researchers recorded a fourfold to sevenfold reduction in the number of elephant seals killed by great white sharks during years in which they were scared away. The findings were described in a study published in April in Scientific Reports.
In a recent paper in Nature Astronomy, researchers from the Max Planck Institute for Gravitational Physics (Albert Einstein Institute/AEI) in Potsdam and from the French Alternative Energies and Atomic Energy Commission (CEA) in Saclay, Paris suggest how the planned space-based gravitational-wave observatory LISA can detect exoplanets orbiting white dwarf binaries everywhere in our Milky Way and in the nearby Magellanic Clouds.
This new method will overcome certain limitations of current electromagnetic detection techniques and might allow LISA to detect planets down to 50 Earth masses. In the past two decades, our knowledge of exoplanets has grown significantly, and more than 4,000 planets orbiting a large variety of stars have been discovered. Up to now, the techniques used to find and characterize these systems are based on electromagnetic radiation and are limited to the solar neighborhood and some parts of our galaxy.
In a recent paper published in Nature Astronomy, Dr. Nicola Tamanini, researcher at the AEI in Potsdam and his colleague Dr. Camilla Danielski, researcher at the CEA/Saclay (Paris) show how these limitations may be overcome by gravitational-wave astronomy. "We propose a method which uses gravitational waves to find exoplanets that orbit binary white dwarf stars", says Nicola Tamanini.
White dwarfs are very old and small remnants of stars once similar to our Sun. "LISA will measure gravitational waves from thousands of white dwarf binaries. When a planet is orbiting such a pair of white dwarfs, the observed gravitational-wave pattern will look different compared to the one of a binary without a planet. This characteristic change in the gravitational waveforms will enable us to discover exoplanets."
Exactly how fast is the universe expanding? Scientists are still not completely sure, but a Princeton-led team of astrophysicists has used the neutron star merger detected in 2017 to come up with a more precise value for this figure, known as the Hubble constant. Their work appears in the current issue of the journal Nature Astronomy.
“The Hubble constant is one of the most fundamental pieces of information that describes the state of the universe in the past, present and future,” said Kenta Hotokezaka, the Lyman Spitzer, Jr. Postdoctoral Fellow in Princeton’s Department of Astrophysical Sciences. “So we’d like to know what its value is.”
Currently, the two most successful techniques for estimating the Hubble constant are based on observations of either the cosmic microwave background or stars blowing themselves to pieces in the distant universe. But those figures disagree: Measurements of exploding stars — Type Ia supernovae — suggest that the universe is expanding faster than is predicted by Planck observations of the cosmic microwave background.
“So either one of them is incorrect, or the models of the physics which underpin them are wrong,” said Hotokezaka. “We’d like to know what is really happening in the universe, so we need a third, independent check.”
He and his colleagues — Princeton’s NASA Sagan Postdoctoral Fellow Kento Masuda, Ore Gottlieb and Ehud Nakar from Tel Aviv University in Israel, Samaya Nissanke from the University of Amsterdam, Gregg Hallinan and Kunal Mooley from the California Institute of Technology, and Adam Deller from Swinburne University of Technology in Australia — found that independent check by using the merger of two neutron stars.
Scientists at The University of Toledo investigating improvements to a commonly used chemotherapy drug have discovered an entirely new class of cancer-killing agents that show promise in eradicating cancer stem cells.
Their findings could prove to be a breakthrough in not only treating tumors, but ensuring cancer doesn't return years later -- giving peace of mind to patients that their illness is truly gone.
"Not all cancer cells are the same, even in the same tumor," said Dr. William Taylor, a professor in the Department of Biological Sciences in the UToledo College of Natural Sciences and Mathematics. "There is a lot of variability and some of the cells, like cancer stem cells, are much nastier. Everyone is trying to figure out how to kill them, and this may be one way to do it."
Taylor and Dr. L.M. Viranga Tillekeratne, a professor in the Department of Medicinal and Biological Chemistry in the UToledo College of Pharmacy and Pharmaceutical Sciences, reported their findings in a paper recently published in the journal Scientific Reports.
Cancer stem cells are an intriguing target for researchers because of their potential to re-seed tumors. When doctors remove a tumor surgically or target it with chemotherapy drugs or radiation therapy, the cancer may appear to be gone. However, evidence suggests that a tiny subpopulation of adaptable cancer cells can remain and circulate through the body to seed new metastasis in far-off locations. Those cancer stem cells, Taylor said, are similar to dandelions in a well-manicured lawn. "You could chop the plant off, but it will drop a seed. You know the seeds are there, but they're hiding," he said. "You pull one weed out and another comes up right after it. Cancers can be like this as well."
Acquista Online La Prescrizione Di Perdita Di Peso Crediamo che i farmaci a volte possano essere molto urgenti da assumere. Se hai urgente bisogno di farmaci, possiamo anche fornirti una consegna espressa,
The moon’s light influences lion prey behavior, dung beetle navigation, fish growth, mass migrations and birdsong.
Crowds of people gather to watch an evening spectacle on beaches in Southern California: Twice a month, typically from March through August, the sand becomes carpeted with hundreds or thousands of California grunion. Writhing, flopping, silvery sardine look-alikes lunge as far onto shore as possible. As the female fish dig their tails into the sand and release eggs, males wrap around females and release sperm to fertilize those eggs. About 10 days later, the eggs hatch and the little grunion get washed out to sea.
This mating ritual is set to the tides, with hatching timed to the arrival of the peak high tide every two weeks. But the ultimate force choreographing this dance is the moon.
Many people know that the moon’s gravitational tug on the Earth drives the tides, and with them, the life cycles of coastal creatures. Yet the moon also influences life with its light.
When it comes to affairs of the heart, there are a variety of factors at play: mutual attraction, shared interests, an intangible spark that eventually leads to love. But in Darwinian terms, the recipe for reproduction is far more clinical, with animals seeking mates based on the potential evolutionary advantage—often superior cognition skills—offered by a match.
Now, a new study published in the journal Science suggests that female budgerigars, a species of small Australian parrots better known as budgies, employ this selective brand of logic when playing the mating game. As Nick Carne writes for Cosmos, a team of Chinese and Dutch researchers found that female budgies preferred brains over beauty and brawn. The birds would even change their selection if the previously overlooked mate learned a new trick.
To test budgies’ mating preferences, a team of researchers led by Jiani Chen of the Chinese Academy of Sciences’ Institute of Zoology, put 34 male and 17 female birds to the test. According to Forbes, the animals were split into a problem-solving group of 18 males and 9 females and a control group of 16 males and 8 females.
In order to watch interactions unfold, the scientists placed three birds into a divided enclosure in which the female could only engage with one male at a time, reports Agence France-Presse. Females in both groups were observed choosing between two similar-looking males, as determined by which male the female bird opted to spent more time with. Past studies structured this way have shown that females will gravitate toward males with beautiful feathers or skilled singing, as two behavioral experts not involved in the study, Georg Striedter and Nancy Burley—both from the University of California, Irvine—explain in an editorial analyzing the new study that was also published in Science.
Theories concerning the cause of right- or left-hand preference in humans vary from purely learned behavior, to solely genetics, to a combination of the two mechanisms. The cause of handedness and its relation to the biologically specified scalp hair-whorl rotation has also been determined. The general public, consisting of mostly right-handers (RH), shows counterclockwise whorl rotation infrequently in 8.4% of individuals. Interestingly, non-right-handers (NRH, i.e., left-handers and ambidextrous) display a random mixture of clockwise and counterclockwise swirling patterns. Confirming this finding, in another independent sample of individuals chosen because of their counterclockwise rotation, one-half of them are NRH.
These findings of coupling in RH and uncoupling in NRH unequivocally establish that these traits develop from a common genetic mechanism. Another result concerning handedness of the progeny of discordant monozygotic twins suggests that lefties are one gene apart from righties. Together, these results suggest (1) that a single gene controls handedness, whorl orientation, and twin concordance and discordance and (2) that neuronal and visceral (internal organs) forms of bilateral asymmetry are coded by separate sets of genetic pathways. The sociological impact of the study is discussed.
Handedness has been extensively studied in the past century, but its exact cause remains debatable (Perelle and Ehrman 1983; Bishop2001). The debate starts with the definition of handedness. Although a layperson knows about hand preference, all studies must first assess the parameters of handedness. This is because the inclination to use one hand over the other for certain tasks is biased due to culture. Studies that monitor only a single trait, such as writing-hand use, to determine the cause of handedness are flawed, because the practice of writing is a learned behavior; consequently, hand preference can be culturally influenced. Such a cultural bias greatly blurs the issue for determining the exact cause of handedness.
One of the best definitions of handedness was used in a study done in North America by D. C. Rife (Rife 1940), whose definition took such cultural biases into consideration. According to this stringent definition, individuals are considered right-handed (RH) if they prefer to use the right hand to throw a ball, use a spoon, saw, sew, shoot marbles, bowl, cut with a knife, cut with scissors, hammer, and write. If they routinely use the left hand or either hand for any number of these 10 tasks, they are designated non-right-handed (NRH). Thus, both left-handers and ambidextrous individuals are pooled as NRH. This definition seems to compensate for cultural bias for individual tasks.
The researchers previously used Rife's definition to calculate the allele frequency (Klar 1996); the same definition of handedness is used in this study here for better comparison between results of this study with an earlier one. As other studies have used different criteria, controversial stances of different investigators are expected. Following different definitions, the prevalence of NRH in different studies varies from 9 to 11% (Rife 1940; Perelle and Ehrman 1983; Corballis 1991).
The contribution of genetics in handedness has been supported by studies of families of concordant twins and adopted individuals (Levy and Nagylaki 1972; Annett 1985a; McManus 1985; Klar 1996; Corballis1997). However, because the Mendelian mode of inheritance has not been demonstrated for handedness, psychologists have not accepted the purely genetic mechanism. Rather, a major school of thought proposes that handedness is primarily, or at least partially, a learned behavior (Collins 1977; Corballis and Morgan 1978; Coren 1992). Other environmental factors, including brain damage resulting from stress during birth (Bakanet al. 1973; Perelle and Ehrman 1983), or a surge of fetal testosterone level during pregnancy (Geschwind and Galaburda1987), are additional mechanisms that have been proposed. However, evidence for such theories is lacking. A later study proposed a gene-culture coevolution model (Lalandet al. 1995). In this model, selection is thought to have eliminated all genetic variation contributing to handedness such that all individuals are predisposed to be RH, but cultural influences dictate their hand use; in short, only the individual's upbringing determines handedness.
Studies favoring the cultural model of handedness present three major arguments against the purely genetic model. First, hand use of some individuals had been culturally changed. Second, up to one-half of the children born to left-handed (LH) × LH parents are RH (Rife1940). Third, and probably most importantly, 18% of individual members of monozygotic (MZ; “identical”) twins are discordant (i.e., one twin RH and the co-twin NRH), despite sharing the same genes (Rife 1940; Boklage 1981). Because of these arguments, combined with the major disagreements among proponents of the earlier genetic models postulating vastly different allele frequencies controlling handedness (Annett 1985a; McManus 1991), researchers often consider handedness to be a classic “complex trait” that is specified by a combination of genetics and environmental causes. Understandably, psychologists have not accepted the prevailing single-gene genetic models (Annett 1985a; McManus 1985; Klar 1996). Indeed, more recent studies on the subject also conclude that genes do not play a significant role in handedness (Bishop 2001; James and Orlebeke 2002). Thus, both environmental and genetic models have been proposed to explain the etiology of human handedness.
So far no locus attributed to handedness has been mapped (Franckset al.2002; Van Agtmaelet al. 2002) and the field remains controversial. Certainly, multiple points of view exist and a consensus has not been achieved thus far, despite a long-time interest in and much literature published on the topic. Indeed, the debate regarding the cause(s) of handedness is a classic example of the controversy over the relative importance of “nature” (biological endowment) vs. “nurture” (environment and culture) on human behavior. It seems that tests more definitive than the ones employed earlier are required to differentiate between these models. This study tested and satisfied three key predictions of a genetic model by conducting two independent lines of investigations. Individuals of the general public and the progeny of handedness-discordant twins were investigated. On the basis of this work, we advance a conclusion opposite to that of an earlier study involving hair whorls. This study unequivocally indicates a “nature” explanation in specifying handedness.
When medical devices are implanted in the body, the immune system often attacks them, producing scar tissue around the device. This buildup of tissue, known as fibrosis, can interfere with the device’s function.
MIT researchers have now come up with a novel way to prevent fibrosis from occurring, by incorporating a crystallized immunosuppressant drug into devices. After implantation, the drug is slowly secreted to dampen the immune response in the area immediately surrounding the device.
“We developed a crystallized drug formulation that can target the key players involved in the implant rejection, suppressing them locally and allowing the device to function for more than a year,” says Shady Farah, an MIT and Boston Children’s Hospital postdoc and co-first author of the study, who is soon starting a new position as an assistant professor of the Wolfson Faculty of Chemical Engineering and the Russell Berrie Nanotechnology Institute at Technion-Israel Institute of Technology.
The researchers showed that these crystals could dramatically improve the performance of encapsulated islet cells, which they are developing as a possible treatment for patients with type 1 diabetes. Such crystals could also be applied to a variety of other implantable medical devices, such as pacemakers, stents, or sensors.
Former MIT postdoc Joshua Doloff, now an assistant professor of Biomedical and Materials Science Engineering and member of the Translational Tissue Engineering Center at Johns Hopkins University School of Medicine, is also a lead author of the paper, which appears in the June 24 issue of Nature Materials. Daniel Anderson, an associate professor in MIT’s Department of Chemical Engineering and a member of MIT’s Koch Institute for Integrative Cancer Research and Institute for Medical Engineering and Science (IMES), is the senior author of the paper.
Crystalline drug
Anderson’s lab is one of many research groups working on ways to encapsulate islet cells and transplant them into diabetic patients, in hopes that such cells could replace the patients’ nonfunctioning pancreatic cells and eliminate the need for daily insulin injections.
Fibrosis is a major obstacle to this approach, because scar tissue can block the islet cells’ access to the oxygen and nutrients. In a 2017 study, Anderson and his colleagues showed that systemic administration of a drug that blocks cell receptors for a protein called CSF-1 can prevent fibrosis by suppressing the immune response to implanted devices. This drug targets immune cells called macrophages, which are the primary cells responsible for initiating the inflammation that leads to fibrosis.
Machine enhanced humans -- or cyborgs as they are known in science fiction -- could be one step closer to becoming a reality, thanks to new research Lieber Group at Harvard University, as well as scientists from University of Surrey and Yonsei University.
Researchers have conquered the monumental task of manufacturing scalable nanoprobe arrays small enough to record the inner workings of human cardiac cells and primary neurons.
The ability to read electrical activities from cells is the foundation of many biomedical procedures, such as brain activity mapping and neural prosthetics. Developing new tools for intracellular electrophysiology (the electric current running within cells) that push the limits of what is physically possible (spatiotemporal resolution) while reducing invasiveness could provide a deeper understanding of electrogenic cells and their networks in tissues, as well as new directions for human-machine interfaces.
In a paper published by Nature Nanotechnology, scientists from Surrey's Advanced Technology Institute (ATI) and Harvard University detail how they produced an array of the ultra-small U-shaped nanowire field-effect transistor probes for intracellular recording. This incredibly small structure was used to record, with great clarity, the inner activity of primary neurons and other electrogenic cells, and the device has the capacity for multi-channel recordings.
Dr Yunlong Zhao from the ATI at the University of Surrey said: "If our medical professionals are to continue to understand our physical condition better and help us live longer, it is important that we continue to push the boundaries of modern science in order to give them the best possible tools to do their jobs. For this to be possible, an intersection between humans and machines is inevitable.
"Our ultra-small, flexible, nanowire probes could be a very powerful tool as they can measure intracellular signals with amplitudes comparable with those measured with patch clamp techniques; with the advantage of the device being scalable, it causes less discomfort and no fatal damage to the cell (cytosol dilation). Through this work, we found clear evidence for how both size and curvature affect device internalisation and intracellular recording signal."
Professor Charles Lieber from the Department of Chemistry and Chemical Biology at Harvard University said: "This work represents a major step towards tackling the general problem of integrating 'synthesised' nanoscale building blocks into chip and wafer scale arrays, and thereby allowing us to address the long-standing challenge of scalable intracellular recording.
To get content containing either thought or leadership enter:
To get content containing both thought and leadership enter:
To get content containing the expression thought leadership enter:
You can enter several keywords and you can refine them whenever you want. Our suggestion engine uses more signals but entering a few keywords here will rapidly give you great content to curate.
Your new post is loading...
