Channel Makeover Bioengineered To Switch Off Neurons
Scientists have bioengineered, in neurons cultured from rats, an enhancement to a cutting edge technology that provides instant control over brain circuit activity with a flash of light.
Deisseroth’s team had pioneered the use of light pulses to control brain circuitry in animals genetically engineered to be light-responsive — optogenetics. Genes that allow the sun to control light-sensitive primitive organisms like algae, melded with genes that make fluorescent marker proteins, are fused with a deactivated virus that delivers them to specific types of neurons which they become part of — allowing pulses of light to similarly commandeer brain cells.

When a neuron fires depends on the balance of ions flowing across the cell membrane, so being able to experimentally control this cellular machinery is critical for understanding how the brain works. But until now, the optogenetic tools for turning off neurons have been much less powerful than for turning them on — a weak inhibitory pump, moving only one ion per photon of light, versus an efficient excitatory channel.

Stanford bioengineers and their colleagues recently discovered the crystal structure of channelrhodopsin, the protein borrowed from algae to achieve optogenetic control of neurons. To transform this excitatory channel into an effective inhibitory channel, the team systematically introduced mutations into the channel’s gene, gradually reshaping its structure through molecular engineering into one with optimal inhibitory properties. To become an effective inhibitory channel, its central pore needed to be lined with positive instead of negatively charged amino acids to be converted from a cation (positive ion)-conducting into an anion (negative ion) -conducting channel.

It turns out that there are economies of scale afforded by the transformed channel — the more the inhibition, the less light required to achieve the desired biological effect. This raises possible future therapeutic applications, such as in the management of pain, said Deisseroth.
http://www.nih.gov/news/health/apr2014/nimh-24.htm

Skin Layer Grown From Human Stem Cells Could Replace Animals In Drug, Cosmetics Testing

Suspended for teaching science!
A Los Angeles high school science teacher is returning to the classroom two months after being suspended over concerns that two students had assembled "dangerous" science projects under his supervision.

Both projects overseen by teacher Greg Schiller were capable of launching small objects. A staff member at the downtown Cortines School of Visual & Performing Arts had raised concerns about one of them. Both are common in science fairs.

"I am very excited to be back with my students and help them prepare for the Advanced Placement tests, which are a week away," Schiller said Thursday. "We have a lot of work ahead of ourselves.”

In a meeting with a senior district administrator, Schiller was told he could return to work Friday, L.A. Unified confirmed.

His classes include Advanced Placement Biology and Advanced Placement Psychology.

Parents and students had quickly rallied behind Schiller. Facebook pages were launched; petitions were circulated. Some students complained that they were being taught by unqualified substitutes. Supporters vowed to rally every Thursday and Friday until his return. A walkout and protest at L.A. Unified school district headquarters was planned for Monday.

Schiller, 43, had volunteered to help students with entries for science contests. He assisted them with ideas related to chemistry and physics, even though he didn't teach those subjects.

Schiller had yet to see either finished display when a school employee noticed one on exhibit in the cafeteria on Feb. 26. Pieces of the other project were in Schiller's classroom.

One of the projects, called a coil gun, was made by ninth-grader Asa Ferguson. It used a magnetic charge powered by an AA battery to launch a small object several feet. His parents, Rogan and Susan Ferguson, both are teachers in L.A. Unified.

The other project was designed to use air pressure for propulsion. A more powerful version was tried out by President Obama at a recent White House science fair.

http://www.latimes.com/local/lanow/la-me-ln-teacher-reinstated-2014...

http://www.latimes.com/local/lanow/la-me-ln-teacher-reinstated-2014...

The strikingly beautiful snow leopards are in "real danger" and there was need to observe, study and develop ways to conserve this rare and endangered species as only 400-700 of the world's best mountain climbers remain in India, according to a leading conservation organisation.

Launching a campaign "Save Our Snow Leopards", WWF-India said that poaching is the major challenge for the protection of this so magnificent species found high altitude Himalayan region.

Snow leopards are poached for their pelts while their bones and other body parts are also in demand for use in traditional Asian medicines, it said.

Retaliatory killing of snow leopards is also a major threat faced by the species since they often attack livestock, causing economic loss to local communities, WWF-India said.

Snow leopards also face habitat and prey loss with the increase of human settlements and developmental activities in their territories.

The snow leopard is found across almost 1,29,000 sq kms in India, in the states of Jammu and Kashmir, Uttarakhand, Himachal Pradesh, Sikkim and Arunachal Pradesh.

"But with an estimated population of only 400-700 in India, there is a dire need to observe, study and develop ways to help conserve this rare and endangered species," it said.

The WWF-India said that the snow leopard is at the apex of the mountain eco-system and is also an indicator species for the high altitude mountain ecosystem.

"By protecting the snow leopard, we ensure the conservation of our fragile mountain landscapes that are one of the largest sources of freshwater for the Indian subcontinent," it said.

The WWF-India said that "Save Our Snow Leopards" is a call for each of us to come forward in support of the snow leopard.
-PTI

Scientists have come up with a way to make whole brains transparent, so they can be labelled with molecular markers and imaged using a light microscope. The technique, called CLARITY, enabled its creators to produce the detailed 3D visualisations you see in this video. It works in mouse brains and human brains; here the team use it to look into the brain of a 7-year-old boy who had autism.

Original research paper: http://dx.doi.org/10.1038/nature12107
Nature News story: http://www.nature.com/news/see-throug...

A new study published online in the Journal of Applied Physiology shows additional benefits of consuming a blend of soy and dairy proteins after resistance exercise for building muscle mass. Researchers from the University of Texas Medical Branch found that using a protein blend of soy, casein and whey post-workout prolongs the delivery of select amino acids to the muscle for an hour longer than using whey alone. It also shows a prolonged increase in amino acid net balance across the leg muscle during early post-exercise recovery, suggesting prolonged muscle building. The study was conducted by researchers from UTMB in collaboration with DuPont Nutrition and Health. "This study sheds new light on how unique combinations of proteins, as opposed to single protein sources, are important for muscle recovery following exercise and help extend amino acid availability, further promoting muscle growth," said Blake B. Rasmussen, chairman of UTMB's Department of Nutrition and Metabolism and lead researcher of the study.

The Secret Life of Scientists and Engineers is an Emmy-nominated web series and site from PBS’s NOVA. This is where you can learn about cutting-edge science and engineering, the amazing people who do that work, and the things they do when their lab coats come off – win beauty pageants, wrestle professionally, become rock stars and magicians, etc. Scroll down to explore the lives of some gifted and inspiring people who are changing our world… and having a great time while they’re doing it.
http://www.pbs.org/wgbh/nova/blogs/secretlife/video-profiles/

Almost a third of malaria drugs failed quality tests

Around 30 per cent of samples tested since 1946 were falsified or substandard

These put patients’ health at risk and could lead to drug-resistant malaria

Sixty-three malaria-endemic nations lack publicly available drug quality data
http://www.scidev.net/global/malaria/news/almost-a-third-of-malaria...

Water-testing lab packed into a pill
Want to know if your water supply is contaminated? Drop this pill in a vial of water and if the colour changes, there's your answer ! Scientists have solved the problem of cumbersome, painfully slow water-testing by putting the potentially life-saving technology into a tiny pill.

The team at McMaster University has reduced the sophisticated chemistry required for testing water safety to a simple pill, by adapting technology found in a dissolving breath strip. Instead of shipping water to the lab, they have created a way to take the lab to the water, putting potentially lifesaving technology into the hands of everyday people.

The development has the potential to dramatically boost access to quick and affordable testing around the world. "We got the inspiration from the supermarket," said Carlos Filipe, who worked on the project.

The idea occurred to Sana Jahanshahi-Anbuhi , a PhD student in Chemical Engineering who came across the breath strips while shopping and realized the same material used in the dissolving strips could have broader applications.

The technology is expected to have significant public health applications for testing water in remote areas and in developing countries that lack proper testing infrastructure.

The researchers have now created a way to store precisely measured amounts of enzymes and other active agents in pills made from the same naturally occurring substance used in breath strips, putting lab-quality science within instant and easy reach of people who need quick answers to questions such as whether their water is safe.
-Agencies

Green jet fuel:

An EU-funded research project called Solar Jet has produced the world's first 'solar' jet fuel from water and carbon dioxide. Researchers have successfully demonstrated the entire production chain for renewable kerosene using concentrated light as a hightemperature energy source.

The project is still at an experimental stage and just a glassful of jet fuel was produced in lab conditions using simulated sunlight.

The four-year Solar-Jet project was launched in June 2011 and is receiving 2.2 million EU funding from the Seventh Framework Programme for Research and Technological Development.

In the next phase of the project, the partners plan to optimize the solar reactor and assess whether the technology will work on a larger scale and at competitive cost. Finding new, sustainable sources of energy will remain a priority under Horizon 2020, the seven-year EU research and innovation programme launched on Jan 1, 2014.

European commissioner for Research, Innovation and Science Maire Geoghegan-Quinn said, "This technology means we might one day produce cleaner and plentiful fuel for planes, cars and other forms of transport. This could greatly increase energy security and turn one of the main greenhouse gases responsible for global warming into a useful resource."

Concentrated light— simulating sunlight —was used to convert carbon dioxide and water to synthesis gas (syngas ) in a high-temperature solar reactor containing metaloxide based materials developed at ETH Zurich . The syngas (a mixture of hydrogen and carbon monoxide) was then converted into kerosene by Shell.

Although producing syngas through concentrated solar radiation is still at an early stage of development, the processing of syngas to kerosene is being deployed by companies including Shell on a global scale. Combining the two approaches has the potential to provide secure, sustainable and scalable supplies of aviation fuel as well as diesel and gasoline, or even plastics.

In the first step, concentrated light - simulating sunlight - was used to convert carbon dioxide and water to synthetic gas known as syngas.

This was done in a high-temperature solar reactor containing metal-oxide based materials.

The syngas - a mixture of hydrogen and carbon monoxide - was then converted into kerosene by Shell using the established Fischer-Tropsch process.

Although producing syngas through concentrated solar radiation is still at an early stage of development, the processing of syngas to kerosene is already being deployed by companies, including Shell, on a global scale.

Combining the two approaches has the potential to provide secure, sustainable and scalable supplies of aviation fuel as well as diesel and gasoline, or even plastics.

Mother’s Womb Can Influence Baby’s Genome:Study
A study of umbilical cord tissue from 237 Asian individuals showed that the interaction between the genome and the prenatal environment can have a profound impact on epigenetic variation.
" The effect of genotype and in utero environment on inter-individual variation in neonate DNA methylomes"

Abstract

Integrating the genotype with epigenetic marks holds the promise of better understanding the biology that underlies the complex interactions of inherited and environmental components that define the developmental origins of a range of disorders. The quality of the in utero environment significantly influences health over the lifecourse. Epigenetics and in particular DNA methylation marks have been postulated as a mechanism for enduring effects of the prenatal environment. Accordingly, neonate methylomes contain molecular memory of the individual in utero experience. However, inter-individual variation in methylation can also be a consequence of DNA sequence polymorphisms that result in methylation quantitative trait loci (methQTLs) and, potentially, the interaction between fixed genetic variation and environmental influences. We surveyed the genotypes and DNA methylomes of 237 neonates and found 1423 punctuate regions of the methylome that were highly variable across individuals, termed variably methylated regions (VMRs), against a backdrop of homogeneity. MethQTLs were readily detected in neonatal methylomes and genotype alone best explained about 25% of the VMRs. We found that the best explanation for 75% of VMRs was the interaction of genotype with different in utero environments, including maternal smoking, maternal depression, maternal BMI, infant birth weight, gestational age and birth order. Our study sheds new light on the complex relationship between biological inheritance as represented by genotype and individual prenatal experience and suggests the importance of considering both fixed genetic variation and environmental factors in interpreting epigenetic variation.
http://genome.cshlp.org/content/early/2014/04/07/gr.171439.113

Asians, African Americans and Pacific Islanders have a higher risk of the autoimmune disorder Graves’ disease than Caucasians, according to a study.
''Variation in Rates of Autoimmune Thyroid Disease by Race/Ethnicity in US Military Personnel''
Researchers in Australia have found that ethnicity affects rates of the thyroid disorder Graves’ disease.
http://jama.jamanetwork.com/article.aspx?articleid=1860451

South Korean scientists have discovered how the colon hedges against cancerous cellular mutation.
South Korean scientist Cho Kwang-Hyun has identified the cancer inhibitory mechanism of the colon tissue, providing insights into the cause of colorectal cancer.
'' The APC Network Regulates the Removal of Mutated Cells from Colonic Crypts''
http://www.cell.com/cell-reports/abstract/S2211-1247%2814%2900157-0...

The Pen Is Mightier Than the Keyboard
Advantages of Longhand Over Laptop Note Taking
Students retain information better with pens than laptops
Writing notes by hand may lead to deeper understanding of lecture material, study suggests

Abstract

Taking notes on laptops rather than in longhand is increasingly common. Many researchers have suggested that laptop note taking is less effective than longhand note taking for learning. Prior studies have primarily focused on students’ capacity for multitasking and distraction when using laptops. The present research suggests that even when laptops are used solely to take notes, they may still be impairing learning because their use results in shallower processing. In three studies, we found that students who took notes on laptops performed worse on conceptual questions than students who took notes longhand. We show that whereas taking more notes can be beneficial, laptop note takers’ tendency to transcribe lectures verbatim rather than processing information and reframing it in their own words is detrimental to learning.
http://pss.sagepub.com/content/early/2014/04/22/0956797614524581

Beware of False or Misleading Claims for Treating Autism
http://www.fda.gov/downloads/ForConsumers/ConsumerUpdates/UCM394800...
“There is no cure for autism,” the bulletin states. “So products or treatments claiming to ‘cure’ autism do not work as claimed. The same is true of many products claiming to ‘treat’ autism. Some may carry significant health risks.”

“Autism Speaks and its many partners are working diligently to find treatments for autism that are safe and effective,” comments developmental pediatrician Paul Wang, Autism Speaks senior vice president and head of medical research. “We know that parents often are desperate to find help for their children. It’s tragic when unscrupulous companies take advantage of these families by pushing so-called treatments that are not only ineffective, but may be costly and dangerous.”

Technique traces DNA direct to your ancestor's home 1,000 years ago
A new ground breaking technique has been developed which can locate the village your ancestors lived 1,000 years ago and hence trace back DNA formation.

Previously scientists had been able to link DNA formation to within a 700 km area which in a continent like Europe is very unreliable.

The Geographic Population Structure (GPS) tool created by Eran Elhaik from the University of Sheffield and Tatiana Tatarinova from the University of Southern California works similarly to a satellite navigation system.

The new technique has been 98% successful in locating worldwide populations to their right geographic regions down to their village and/ or island of origin.

The breakthrough has massive implications for life-saving personalized medicine, advancing forensic science and for the study of populations whose ancestral origins are under debate such as African Americans, Roma gypsies and European Jews.

Genetic admixture occurs when individuals from two or more previously separated populations interbreed. This results in the creation of a new gene pool representing a mixture of the founder gene pools.

Elhaik said, "What we have discovered here is a way to find not where you were born but where your DNA was formed up to 1,000 years ago by modelling these admixture processes. What is remarkable is that we can do this so accurately that we can locate the village where your ancestors lived hundreds and hundreds of years ago — until now this has never been possible."

Such processes were extremely common in history during migrations and invasions. When the Vikings invaded Britain and Europe in the 11th century and settled with locals some of them formed a new Viking-Anglo-Saxon gene pool but some married other Vikings and maintained their original gene pool allowing GPS to trace their Scandinavian origins.

Discovery of a certain genotype might indicate the potential for a genetic disease and suggest that diagnostic testing be done. Also as scientists learn more about personalized medicine there is evidence that specific genotypes respond differently to medications — making this information potentially useful when selecting the most effective therapy and appropriate dosage.

To demonstrate how accurate GPS predictions are, Elhaik analyzed data from 10 villages in Sardinia and over 20 islands in Oceania. The team was able to place a quarter of the residents in Sardinia directly to their home village and most of the remaining residents within 50km of their village.

The results for Oceania were no less impressive with almost 90% success of tracing islanders exactly to their island.

Tatarinova has now developed a website making GPS accessible to the public. "To help people find their roots, I developed a website that allows anyone who has had their DNA genotyped to upload their results and use GPS to find their ancestral home," Tatarinova said.

Fiber's ability to curb appetite may come from gut molecules traveling to and acting on the brain, not the gut alone. As mice digest fiber, their guts release a molecule called acetate that appears to influence appetite suppression chemicals sent from the brain, researchers report April 29 in Nature Communications. The finding could open up new possibilities for weight management, the scientists say. It's unclear exactly how the gut-made acetate influences the brain chemicals that regulate appetite, and it's unknown wheather the amount of fiber given to the mice in the study would be part of a realistic diet.

A new study shows how the mammalian brain can distinguish the signal from the noise. Brain cells in the primary auditory cortex can both turn down the noise and increase the gain on the signal. The results show how the brain processes sound in noisy environments, and might eventually help in the development of better voice recognition devices, including improvements to cochlear implants for those with hearing loss. Not to mention getting Siri to understand you on a chaotic street corner.
''Mechanisms of noise robust representation of speech in primary auditory cortex''
the auditory system maintains a robust representation of speech in noisy and reverberant conditions by preserving the same statistical distribution of responses in all conditions. Reconstructed stimulus from population of cortical neurons resembles more the original clean than the distorted signal. We show that a linear spectrotemporal receptive field model of neurons with a static nonlinearity fails to account for the neural noise reduction. Although replacing static nonlinearity with a dynamic model of synaptic depression can account for the reduction of additive noise, only the combined model with feedback gain normalization is able to predict the effects across both additive and reverberant conditions.
Abstract

Humans and animals can reliably perceive behaviorally relevant sounds in noisy and reverberant environments, yet the neural mechanisms behind this phenomenon are largely unknown. To understand how neural circuits represent degraded auditory stimuli with additive and reverberant distortions, we compared single-neuron responses in ferret primary auditory cortex to speech and vocalizations in four conditions: clean, additive white and pink (1/f) noise, and reverberation. Despite substantial distortion, responses of neurons to the vocalization signal remained stable, maintaining the same statistical distribution in all conditions. Stimulus spectrograms reconstructed from population responses to the distorted stimuli resembled more the original clean than the distorted signals. To explore mechanisms contributing to this robustness, we simulated neural responses using several spectrotemporal receptive field models that incorporated either a static nonlinearity or subtractive synaptic depression and multiplicative gain normalization. The static model failed to suppress the distortions. A dynamic model incorporating feed-forward synaptic depression could account for the reduction of additive noise, but only the combined model with feedback gain normalization was able to predict the effects across both additive and reverberant conditions. Thus, both mechanisms can contribute to the abilities of humans and animals to extract relevant sounds in diverse noisy environments.
http://www.pnas.org/content/early/2014/04/17/1318017111

When E. coli cells aren't hanging out in a crowd, the rate at which their genes mutate to resist the antibiotic rifampicin increases up to threefold. The finding shows that the microbes' ability to develop antibiotic resistance depends on a gene that helps the bacterial cells communicate. Manipulating this type of crosstalk among bacterial cells may provide a way to slow the pervasive emergence of antibiotic resistance, researchers suggest April 29 in Nature Communications.

Excessive regulations turning scientists into bureaucrats
Scientists and institutions pinpointed regulations they believe are ineffective or inappropriately applied to research, and audit and compliance activities that take away research time and result in university over-regulation.
http://esciencenews.com/articles/2014/05/01/excessive.regulations.t...

Antimicrobial agents incorporated into edible films applied to foods to seal in flavor, freshness and color can improve the microbiological safety of meats, according to researchers in Penn State's College of Agricultural Sciences. Using films made of pullulan -- an edible, mostly tasteless, transparent polymer produced by the fungus Aureobasidium pulluns -- researchers evaluated the effectiveness of films containing essential oils derived from rosemary, oregano and nanoparticles against foodborne pathogens associated with meat and poultry.

The results demonstrate that the bacterial pathogens were inhibited significantly by the use of the antimicrobial films, said Catherine Cutter, professor of food science. She hopes that the research will lead to the application of edible, antimicrobial films to meat and poultry, either before packaging or, more likely, as part of the packaging process.

In the study, which was published online in the April issue of the Journal of Food Science, researchers determined survivability of bacterial pathogens after treatment with 2 percent oregano essential oil, 2 percent rosemary essential oil, zinc oxide nanoparticles or silver nanoparticles.
http://esciencenews.com/articles/2014/05/01/antimicrobial.edible.fi...

Decoding the chemical vocabulary of plants
Plants spend their entire lifetime rooted to one spot. When faced with a bad situation, such as a swarm of hungry herbivores or a viral outbreak, they have no option to flee but instead must fight to survive. What is the key to their defense? Chemistry. Thanks to this ongoing conflict, plants have evolved into amazing chemists, capable of synthesizing tens of thousands of compounds from thousands of genes. These chemicals, known as specialized metabolites, allow plants to withstand transient threats from their environment. What's more, some of the same compounds benefit humans, with more than a third of medicinal drugs derived from plant specialized metabolites.

Understanding how plants evolved this prodigious chemical vocabulary has been a longstanding goal in plant biology. A team of Carnegie scientists led by Seung Yon Rhee and Lee Chae undertook a large-scale comparative analysis of plant genomes to investigate how specialized metabolism evolved. Their findings, as reported in Science, have major implications for the way scientists search for novel beneficial metabolites in plants.
Collectively, these properties represent a distinct signature of specialized metabolic genes that offers an innovative strategy for the discovery of novel specialized metabolites from various plant species. Such discoveries could have wide-ranging implications for many research fields, including agriculture, biotechnology, drug discovery, and synthetic biology.

"Despite our reliance on plant compounds for health and well-being, we know very little about how they are produced or the true extent of their diversity in nature," says Rhee. "We hope that our findings will enable researchers to use these signatures as a tool to discover previously unknown specialized metabolites, to investigate how they benefit the plant, and to determine how they might benefit us."
http://esciencenews.com/articles/2014/05/01/decoding.chemical.vocab...
Source: Carnegie Institution

Watch the Earth From Space, Live!
http://blogs.scientificamerican.com/life-unbounded/2014/05/01/watch...

“The Improbability Principle” – The Book
Why is it that incredibly unlikely phenomena actually happen quite regularly and why should we, in fact, expect such things to happen? Here, in this highly original book – aimed squarely at anyone with an interest in coincidences, probability or gambling – eminent statistician David Hand answers this question by weaving together various strands of probability into a unified explanation, which he calls the improbability principle.

This is a book that will appeal not only to those who love stories about startling coincidences and extraordinarily rare events, but also to those who are interested in how a single bold idea links areas as diverse as gambling, the weather, airline disasters and creative writing as well as the origin of life and even the universe.

http://improbability-principle.com/the-improbability-principle-the-...

Elephant Seals Reveal Anti-Inflammatory Secrets of Carbon Monoxide
The gas appears to protect the deep-diving seals from cell damage after periods of restricted blood flow
Blood samples from elephant seals may help to explain how carbon monoxide — a poison — can stop inflammation, researchers have found.

The seals routinely dive to depths of 500 metres and stay underwater for 25 minutes at a time, surfacing for just a few minutes between plunges1. During these forays, blood flow to nonessential tissues and organs is restricted, but the tissues are not damaged. Researchers at the Scripps Institution of Oceanography in San Diego, California, suggest that high levels of carbon monoxide in the seals' blood has a protective effect — echoing laboratory research on rats and mice that has found the gas has anti-inflammatory properties and can lead to better outcomes after organ transplant.
http://www.nature.com/news/deep-diving-seals-reveal-secrets-of-carb...

New Super-Heavy Element 117 Confirmed by Scientists

Atoms of a new super-heavy element — the as-yet-unnamed element 117 — have reportedly been created by scientists in Germany, moving it closer to being officially recognized as part of the standard periodic table.

Researchers at the GSI Helmholtz Center for Heavy Ion Research, an accelerator laboratory located in Darmstadt, Germany, say they have created and observed several atoms of element 117, which is temporarily named ununseptium.

Element 117 — so-called because it is an atom with 117 protons in its nucleus — was previously one of the missing items on the periodic table of elements. These super-heavy elements, which include all the elements beyond atomic number 104, are not found naturally on Earth, and thus have to be created synthetically within a laboratory.
http://www.livescience.com/45289-superheavy-element-117-confirmed.html

How bacteria exploit proteins to trigger potentially lethal infections
New research by scientists at the University of York sheds light on how bacteria exploit human proteins during infections. A research team led by Professor Jennifer Potts, a British Heart Foundation Senior Research Fellow in York's Department of Biology, studied how Staphylococcus aureus, which can cause life-threatening human infections, attach to two proteins fibronectin and fibrinogen found in human blood.

The human proteins play important roles in clot formation and wound healing and the bacteria appear to exploit them during the process of infection.
- Journal of Biological Chemistry

How Ancient Egyptians Moved Massive Pyramid Stones
The ancient Egyptians who built the pyramids may have been able to move massive stone blocks across the desert by wetting the sand in front of a contraption built to pull the heavy objects, according to a new study.

Physicists at the University of Amsterdam investigated the forces needed to pull weighty objects on a giant sled over desert sand, and discovered that dampening the sand in front of the primitive device reduces friction on the sled, making it easier to operate. The findings help answer one of the most enduring historical mysteries: how the Egyptians were able to accomplish the seemingly impossible task of constructing the famous pyramids.

To make their discovery, the researchers picked up on clues from the ancient Egyptians themselves. A wall painting discovered in the ancient tomb of Djehutihotep, which dates back to about 1900 B.C., depicts 172 men hauling an immense statue using ropes attached to a sledge. In the drawing, a person can be seen standing on the front of the sledge, pouring water over the sand, said study lead author Daniel Bonn, a physics professor at the University of Amsterdam.
"Egyptologists thought it was a purely ceremonial act," Bonn told Live Science. "The question was: Why did they do it?"

Bonn and his colleagues constructed miniature sleds and experimented with pulling heavy objects through trays of sand.

When the researchers dragged the sleds over dry sand, they noticed clumps would build up in front of the contraptions, requiring more force to pull them across.

Adding water to the sand, however, increased its stiffness, and the sleds were able to glide more easily across the surface. This is because droplets of water create bridges between the grains of sand, which helps them stick together, the scientists said. It is also the same reason why using wet sand to build a sandcastle is easier than using dry sand, Bonn said.

But, there is a delicate balance, the researchers found.

"If you use dry sand, it won't work as well, but if the sand is too wet, it won't work either," Bonn said."There's an optimum stiffness."

The study, published April 29 in the journal Physical Review Letters, may explain how the ancient Egyptians constructed the pyramids.

Is Lead Poisoning one of the reasons for the Down fall of Ancient Rome?
It is now universally accepted that utilization of lead for domestic purposes and water distribution presents a major health hazard. The ancient Roman world was unaware of these risks. How far the gigantic network of lead pipes used in ancient Rome compromised public health in the city is unknown. Lead isotopes in sediments from the harbor of Imperial Rome register the presence of a strong anthropogenic component during the beginning of the Common Era and the Early Middle Ages. They demonstrate that the lead pipes of the water distribution system increased Pb contents in drinking water of the capital city by up to two orders of magnitude over the natural background. The Pb isotope record shows that the discontinuities in the pollution of the Tiber by lead are intimately entwined with the major issues affecting Late Antique Rome and its water distribution system.
http://www.pnas.org/content/early/2014/04/16/1400097111

http://news.sciencemag.org/archaeology/2014/04/scienceshot-did-lead...

MERS is a respiratory virus, known initially as novel coronavirus (CoV). Until now, it has largely been confined to the Middle East, having been first discovered in Saudi Arabia in 2012. One possibility is that camel meat or raw camel milk might be one route of transmission. fruit bats are increasingly thought to be the reservoir for MERS—specifically, the Egyptian tomb bat.
SARS (Severe acute respiratory syndrome coronavirus), which is a cousin to MERS, caused a major worldwide epidemic in 2003, infecting more than 8000 and killing almost 10%. SARS caused major infections in China, Hong Kong and Toronto, among others, before being contained by unprecedented multinational cooperation and careful infection control, within only about a year. SARS was linked to live animal markets, and specifically to civets.

Animals are often the hidden source of outbreaks, known as zoonoses.

Young blood may reverse ageing : Researchers think it may contain natural chemicals that turn back the clock to rejuvenate the ageing brain
Scientists have shown that an infusion of young blood can reverse signs of ageing. Although the experiment was conducted on laboratory mice, the next step could involve a study of elderly humans.
In the study, blood from three-month-old mice was repeatedly injected into 18-month-old mice near the end of their natural life span. The "vampire therapy" improved the performance of the elderly mice in memory and learning tasks. Structural, molecular and functional changes were also seen in their brains.

Writing in the journal Nature Medicine, the US team led by Dr Tony Wyss-Coray, from Stanford University, said: "Our data indicate that exposure of aged mice to young blood late in life is capable of rejuvenating synaptic plasticity and improving cognitive function.

"Future studies are warranted in aged humans and potentially those suffering from age-related neurodegenerative disorders."
Evidence was seen of new connections forming in the hippocampus, a brain region vital to memory and sensitive to ageing.

Ageing mice given eight infusions of young blood over three weeks improved their performance in mental tests. Infusions of blood from other elderly mice had no effect.

What caused the changes is still unknown, but it appears to involve activation of a protein called Creb in the hippocampus that helps regulate certain genes.

The scientists wrote: "One possibility is that introducing 'pro-youthful' factors from aged blood can reverse age-related impairments in the brain, and a second possibility is that abrogating pro-ageing factors from aged blood can counteract such impairments.These two possibilities are not mutually exclusive, warrant further investigation, and may each provide a successful strategy to combat the effects of ageing."

Dr Eric Karran, from the dementia charity Alzheimer's Research UK, described the results as "interesting", but added that the study "does not investigate the type of cognitive impairment that is seen in Alzheimer's disease".

Put science before emotion over radioactive waste
http://bismarcktribune.com/news/columnists/put-science-before-emoti...

Odors define us, yet the scientific zeitgeist is that we don’t communicate through pheromones—scents that influence behavior. A new study challenges that thinking, finding that scent can change whether we think someone is masculine or feminine.

Humans carry more secretion and sweat glands in their skin than any other primate. Yet 70% of people lack a vomeronasal organ, a crescent-shaped bundle of neurons at the base of each nostril that allows a variety of species—from reptiles to nonprimate mammals—to pick up on pheromones. (If you’ve ever seen your cat huff something, he’s using this organ.) Still, scientists have continued to hunt for examples of pheromones that humans might sense.

Two strong candidates are androstadienone (andro) and estratetraenol (estra). Men secrete andro in their sweat and semen, while estra is primarily found in female urine. Researchers have found hints that both trigger arousal—by improving moods and switching on the brain’s “urge” center, the hypothalamus—in the opposite sex. Yet to be true pheromones, these chemicals must shape how people view different genders.

That’s exactly what they do, researchers from the Chinese Academy of Sciences in Beijing report online today in Current Biology.
http://bcove.me/qupsica9
http://news.sciencemag.org/biology/2014/05/man-or-woman-trust-your-...

Some e-cigarettes deliver a puff of carcinogens
Electronic cigarettes appear to be safer than ordinary cigarettes for one simple — and simply obvious — reason: People don't light up and smoke them.

With the e-cigarettes, there is no burning tobacco to produce myriad new chemicals, including some 60 carcinogens.

But new research suggests that, even without a match, some popular e-cigarettes get so hot that they, too, can produce a handful of the carcinogens found in cigarettes and at similar levels.

A study to be published this month in the journal Nicotine and Tobacco Research found that the high-power e-cigarettes known as tank systems produce formaldehyde, a known carcinogen, along with the nicotine-laced vapour that their users inhale. The toxin is formed when liquid nicotine and other e-cigarette ingredients are subjected to high temperatures, according to the study. A second study that is being prepared for submission to the same journal points to similar findings.

The long-term effects of inhaling nicotine vapour are unclear, but there is no evidence to date that it causes cancer or heart disease as cigarette smoking does. Indeed, many researchers agree that e-cigarettes will turn out to be much safer than conventional cigarettes, an idea that e-cigarette companies have made much of in their advertising. The website for Janty, a company that manufactures popular tank systems, says the benefits of e-cigarettes include having "no toxins associated with tobacco smoking."

Nonetheless, the new research suggests how potential health risks are emerging as the multibillion-dollar e-cigarette business rapidly evolves, and how regulators are already struggling to keep pace. While the Food and Drug Administration last month proposed sweeping new rules that for the first time would extend its authority to e-cigarettes, the FDA has focused largely on what goes into these products — currently, an unregulated brew of chemicals and flavourings — rather than on what comes out of them, as wispy plumes of flavoured vapour.
This finding suggests that in certain conditions," e-cigarettes "might expose their users to the same or even higher levels of carcinogenic formaldehyde as tobacco smoke.

How volcanoes erupt: Using friction experiments, University of Liverpool scientists have shown that frictional melting plays a role in determining how a volcano will erupt.
Volcanologists from the University of Liverpool have discovered how lava dome volcanoes erupt. This could help develop methods on predicting how volcanoes will act.

The process of frictional melting determines how the volcano will erupt. The speed of the lava rise and how much friction it creates is determined by this process. Within the lava dome the magma and rocks melt as they rub together by the intense heat. This creates a method called ‘stick-slip’ when the magma adheres to the rocks and stops moving upward until pressure builds — when enough pressure builds up, the magma moves upward again. This process continues until the magma reaches the mouth of the volcano in an eruption.

By studying the stick-slip process, a research team, led by University of Liverpool volcanologist Dr. Jackie Kebdrick, has conducted experiments that could help predict eruptions.

The researchers analyzed lava collected from Mount St. Helens in the United States and the Soufriere Hills volcano in Montserrat. Remnants of pseudotachylyte, which is a cooled friction melt, were found. The study also revealed the process takes place in the conduit leading to the top of the volcano before its eruption.

“The closer we get to understanding the way magma behaves, the closer we will get to the ultimate goal: predicting volcanic activity when unrest begins. Whilst we can reasonably predict when a volcanic eruption is about to happen, this new knowledge will help us to predict how the eruption will behave. With a rapidly growing population inhabiting the flanks of active volcanoes, understanding the behaviour of lava domes becomes an increasing challenge for volcanologists.
http://www.redorbit.com/news/science/1113137915/volcanic-eruption-p...

Making sense of at which direction and at what speed a car is moving may not be possible without the interpretation of the brain, but processing of some of these information starts right at the retinas of the eyes.

Researchers have now explained how the various types of cells in the retina are wired to help the eyes detect the direction and speed of moving objects.

"The wiring diagram represents only a tiny proportion of the total number of connections on the retina," said Sebastian Seung, a computational neuro scientist at Massachusetts Institute of Technology in the US.

To understand how cells are wired together in the retina, the researchers analysed high-resolution electron microscope images of a mouse retina with the help of nearly 2,200 members of EyeWire, an online 'citizen-science' game set up to help with brain-mapping efforts.
To understand how cells are wired together in the retina, the researchers analysed high-resolution electron microscope images of a mouse retina with the help of nearly 2,200 members of EyeWire, an online 'citizen-science' game set up to help with brain-mapping efforts.

Players traced the pathways through the layers of cells to create a high-resolution wiring diagram of part of the retina.

The reconstructed map showed that while one type of bipolar cell (that transmit signals from the photoreceptors to the ganglion cells) connects to the amacrine cells (responsible for 70 percent of input to retinal ganglion cells) filaments close to the cell body, another does do so farther away along the length of the filaments.

The bipolar cells that connect closer to the starburst amacrine cell bodies are known to relay their messages with a time delay, whereas the others transmit their immediately, the researchers discovered.

Because of the lag in the first type of connection, signals that hit two nearby locations on the retina at two slightly different times - as would happen when an object moves across the visual field - could reach the same amacrine-cell filament at the same time.

According to the researchers, the following could help explain how the retina detects motion: The amacrine cell might fire only when it receives this combined information, signalling that something is moving in the direction of the filament.

Stimuli not moving in the direction of the filament would produce impulses that reach the amacrine cell at different times, so that it would not fire.

The study appeared in the journal Nature.