Biophysicists zoom in on pore-forming toxina new study by Rice university biophysicists offers the most comprehensive picture yet of the molecular-level action of melittin the principal toxin in bee venom.
But the clinical use of the compounds is complicated by the lack of consensus about how the peptides work.
The team used a combination of experiments to zero in on the molecular activity of melittin at the minimal inhibitory concentration (MIC) the lowest concentration that's been shown to slow the growth of target cell populations.
We want to understand how pore formation works at this critical concentration including both at the molecular scale
By correlating these findings with other data about the molecular characteristics of the pores themselves we get the first complete picture of the process of stable melittin-induced pore formation.
The molecular level data came from a series of X-ray diffraction experiments performed by Lee at NSRRC.
Measurements indicated that the extreme weather events had a much greater impact on the carbon balance than had previously been assumed.
The indications that the part played by extreme weather events in the carbon balance had been underestimated prompted scientists from eight countries to launch the CARBO-Extreme Project.
Calculations from these values indicate how much carbon an ecosystem absorbs and releases in the form of carbon dioxide.
The team then fed the various readings into complex computer models to calculate the global effect of extreme weather on the carbon balance.
That is roughly equivalent to the amount of carbon sequestered in terrestrial environments every year says Markus Reichstein.
Periods of extreme drought in particular reduce the amount of carbon absorbed by forests meadows and agricultural land significantly.
We have found that it is not extremes of heat that cause the most problems for the carbon balance
As extreme climate events reduce the amount of carbon that the terrestrial ecosystems absorb and the carbon dioxide in the atmosphere therefore continues to increase more extreme weather could result explains Markus Reichstein.
and for toxicology where shockingly few compounds receive critical or long-term toxicity testing. The study was funded by the National institutes of health and the National Science Foundation.
Using mutation rates as a molecular clock the authors determined that the ancestor of clade A jumped from a bovine host to humans between 1894 and 1977
This means that more carbon is accumulating in forests and other vegetation and soils in the Northern hemisphere during the summer and more carbon is being released in the fall
and winter says study lead scientist Heather Graven of SIO. It's not yet understood she says why the increase in seasonal amplitude of carbon dioxide concentration is so large
and higher carbon dioxideconcentrations the change in carbon dioxide amplitude over the last 50 years is expected larger than from these effects.
Other factors may be changes in the amount of carbon in leaves wood or roots; changes in the extent or species composition of ecosystems;
Soot also known as black carbon is made of fine carbon-based particles that are given off by car and truck tailpipes and wood stoves.
With PNNL's climate model Smith created more than 1400 potential scenarios to reflect the many possibilities surrounding aerosols tiny particles including soot that float in the atmosphere.
Ongoing PNNL research is evaluating how aerosol particles affect the atmosphere including temperature and precipitation.
The model also considered how reducing soot could impact other atmospheric emissions including sulfur dioxide nitrous oxide and organic carbon.
#Weeds threaten carbon offset programsresearchers have identified gamba grass and other invasive weeds as a potential threat to landholder involvement in environmental offset programs such as the Carbon Farming Initiative.
Strategic savanna burning is one way to reduce Australia's carbon emissions and create new markets in northern Australia
but the increased fuel load and emissions from weed infestations could make it unfeasible. Dr Vanessa Adams says that late dry season wildfires in Australia's tropical north generate about 3%of the country's annual greenhouse gas emissions so strategic burning could be an important abatement activity.
--and the costs of managing gamba grass--$40 per hectare--meaning that much more savanna needs to be enrolled for carbon farming to cover the costs of weed eradication.
The researchers also attached other components such as molecules to block a protein (laminin-411) that cancer cells need to make new blood vessels for growth.
They are the latest evolution of molecular drugs designed to slow or stop cancers by blocking them in multiple ways.
and length of its branches--predicts how much carbon and water a tree exchanges with the environment in relation to its overall size independently of the species. This theory can be used to scale the size of plants to their function such as amount of photosynthesis water loss
and wanted to know how much carbon this forest puts out our study supports the idea that you might only have to look at the properties of a few trees representing the
#A layer of tiny grains can slow sound wavesin some ways granular material--such as a pile of sand--can behave much like a crystal with its close-packed grains mimicking the precise orderly arrangement of crystalline atoms.
But most such research has focused on the properties of sand-sized particles about a millimeter across Fang says.
The new work is the first to examine the very different properties of particles that are about one-thousandth that size or one micrometer across
which is necessary to form sulforaphane the powerful cancer-preventive compound in broccoli she said.
and undetectable to our taste buds--on the frozen broccoli the two compounds worked together to form sulforaphane Dosz said.
The researchers tested nearly 200 people for their sensitivity for ten different chemical compounds that are commonly found in foods.
They then searched through the subjects'genomes for areas of the DNA that differed between people who could smell a given compound
or cannot smell these compounds. The smells of these four odorants are familiar for those who can smell them
just as likely to be able to smell one of these compounds as someone in Europe or Africa.
What's more the ability to smell one of the compounds doesn't predict the ability to smell the other.
The odorant receptor molecules sit on the surface of sensory nerve cells in our nose. When they bind a chemical compound drifting through the air the nerve cell sends an impulse to the brain leading ultimately to the perception of a smell.
In the case of Î-ionone the smell associated with violets Mcrae and colleagues managed to pinpoint the exact mutation (a change in the DNA sequence) in the odorant receptor gene OR5A1 that underlies the sensitivity to smell the compound
and to perceive it as a floral note--people who are less good at smelling Î-ionone also describe the smell differently as sour
Knowing the compounds that people can sense in foods as well as other products will have an influence on the development of future products.
Close to the nanopillar surface the grains easily slide against each other to create atom-sized steps reducing material strength.
The technique dubbed carbon farming consists in planting trees in arid regions on a large scale to capture CO2.
Carbon farming addresses the root source of climate change: the emission of carbon dioxide by human activities says first-author Klaus Becker of the University of Hohenheim in Stuttgart.
When it comes to sequestering carbon from the atmosphere the team shows that Jatropha curcas does it better.
To our knowledge this is the first time experts in irrigation desalination carbon sequestration economics and atmospheric sciences have come together to analyse the feasibility of a large-scale plantation to capture carbon dioxide in a comprehensive manner.
With about one billion hectares suitable for carbon farming the method could sequester a significant portion of the CO2. added to the atmosphere since the industrial revolution.
Carbon farming's price tag ranges from 42 to 63 euros per tonne of CO2. making it competitive with other CO2. reduction techniques such as carbon capture and storage.
From our point of view afforestation as a geoengineering option for carbon sequestration is the most efficient
The team hopes the new research will get enough people informed about carbon farming to establish a pilot project.
since omega-3 deficiencies causes an increase of omega-6 fats which are proinflammatory molecules in the brain and other tissues.
Lastly unlike the molecules in chemical plant-protection products viruses are able to mutate which limits the development of resistance in their host.
molecular analyses to describe the genetic structure of the pests a study of the impact of temperatures on their ecology by means of drones with thermal cameras#The aim is to get a better understanding of the insects'population dynamics
This is the first time we've detected many of these compounds including fungicides in these remote locations.
and tebuconazole and one herbicide simazine were the most frequently detected compounds and this is the first time these compounds have ever been reported in wild frog tissue.
Another commonly detected pesticide was DDE (Dichlorodiphenyldichloroethylene) a breakdown product of DDT which was banned in the United states in 1972.
This is partly due to the physical chemical properties of the l compounds and biological influences such as such as organism specific metabolism and life history.
Documenting the occurrence of these compounds is an important first step in figuring out the health consequence associated with the exposures.
Identification of the closest known relatives of this fungus makes it possible to move forward with genetic work to examine the molecular toolbox this fungus uses to kill bats according to Lindner a research plant pathologist.
and land usethe discovery of the Shell gene and its two naturally occurring mutations highlight new molecular strategies to identify seeds
and can readily be produced mass--can be engineered to produce molecules that can cure parasitic diseases.
Otherwise the loss of wildlife will result in a disastrous spiral of forest degradation that will reduce the storage of carbon and the resilience of rainforests to climate change.
and apes could reduce the ability of forests to sequester carbon. The clock is ticking on the future of large mammals in Central africa's Congo Basin Rainforest
#First high-resolution national carbon map of Panamaa team of researchers has mapped for the first time the above ground carbon density of an entire country in high fidelity.
and to quantify carbon stocks throughout the Republic of Panama. The results are the first maps that report carbon stocks locally in areas as small as a hectare (2. 5 acres)
and yet cover millions of hectares in a short time. The system has demonstrated the lowest uncertainty of any carbon-counting approach yet--a carbon estimation uncertainty of about 10%in each hectareoverflown with Lidar as compared to field-based estimates.
Importantly it can be used across a wide range of vegetation types worldwide. The new system described in Carbon Balance
and Management will greatly boost conservation and efforts to mitigate climate change through carbon sequestration.
It will also inform our understanding of how carbon storage can be used to assess other fundamental ecosystem characteristics such as hydrology habitat quality and biodiversity.
The approach provides much-needed technical support for carbon-based economic activities such as the United nations Reducing Emissions from Deforestation and Forest Degradation (REDD) program in developing countries.
Panama has complex landscapes with variable topography and diverse ecosystems (ranging from grasslands and mangroves to shrublands and dense forests).
and test a method for quantifying aboveground carbon. Lead author Greg Asner commented: Three things make this national-scale study unique.
First Panama is an outstanding place for testing carbon mapping approaches due in part to the long-term forest studies that have been undertaken by our partners at the Smithsonian Tropical Research Institute (STRI.
Lidar uses reflected laser light to image vegetation canopy structure in 3-D. The scientists calibrated the Lidar measurements taken at one-meter resolution throughout nearly one million acres (390000 hectares) to the carbon
They used 91 other plots to validate the Lidar's aboveground carbon density estimates. Rarely has such a large number of field plots been available to validate Lidar calibration independently remarked Asner.
Traditional carbon monitoring has relied upon on-the-ground sampling of field plots but this approach usually represents just small areas of land
It directly probes the ecosystem's physical structure which Carnegie scientists have repeatedly proven to be linked tightly to tropical carbon stocks.
and estimating the amount of carbon locked up in plants from dense forests to shrublands. The researchers then were able to scale up the plot and Lidar data with freely available satellite data on topography rainfall and vegetation to model carbon stocks at the national level.
The Lidar and satellite combination were able to account for variations in the carbon pattern from differences in elevation slope climate
and fractional canopy cover over the entire country. For instance the scientists found that highest carbon levels are in humid forests on the Caribbean side of Panama often exceeding 110 tons of carbon per hectare (2. 5 acres.
In contrast large regions were deforested to very low carbon levels such as in the developed regions outside the protected watershed of the Panama canal.
Human activity is the overwhelming driver of carbon stock patterns in Panama. Panama is one of the first UN REDD partner countries
and these new maps put the country at the forefront of high-resolution ecosystem management. said co-author
and STRI's director Eldredge Bermingham The new carbon mapping approach could be the model for other tropical nations.
Watch the Carnegie Airborne Observatory make the world's highest resolution carbon map of a country (Panama) in less than one minute http://www. youtube. com/watch?
and contain a vast amount of carbon primarily in the soil Kelly said. There is more carbon in the boreal forests than in the atmosphere he said.
And one of the main ways that the carbon that's accumulated over thousands of years gets out of the soil is through burning.
The release of this carbon from fires adds to the greenhouse gases in the atmosphere potentially leading to additional climate warming he said.
The Yukon Flats region appears to be undergoing a transition that is unprecedented in the Holocene epoch Hu said.
and studying light-activated particles. One of her creations gold nanoshells is the subject of several clinical trials for cancer treatment.
and exposed to sunlight the particles heat up so quickly they instantly vaporize water and create steam.
Loss of trees could impact on climate change as forests store carbon in their stems
Land use in Africa influences how much its forests can grow--and their capacity for absorbing carbon emissions.
and help to limit the impact of carbon emissions but instead in many places people are impacting more on woodlands
and forests adding to carbon emissions. Story Source: The above story is provided based on materials by University of Edinburgh.
Measurement of predicted particle decay with implications for dark matter searcha discovery facilitated by Rice university's contribution to the Large Hadron Collider (LHC) will impact scientists'search for dark matter in the universe.
That match with only a 1-in-100000 chance of being caused by a statistical error virtually eliminates any possibility that B-sub-s meson decay is related to interaction with particles predicted by dark matter theories as some physicists have suspected.
The particle itself was discovered quite some time ago and that isn't news said Rice physicist Paul Padley a co-investigator on the CMS experiment
But there has been the possibility it could decay through new particles predicted by dark matter theories such as supersymmetry.
or other new particles then the prediction of how often this decay should happen would be wrong.
The carbon emissions generated by a search on Google or a post on Facebook are related mostly to three things:
and how much of the center's electricity comes from renewable or low-carbon sources. Adding renewable power to the mix can help reduce a data center's overall emissions by 98 percent
Of these three improving the efficiency of the IT devices is overwhelmingly the most important said Jonathan Koomey a co-author of the study Characteristics of Low-Carbon Data centers published online June 25 in Nature Climate Change.
and in many of the countries where they operate carbon emissions have a cost or soon will.
and are responsible for about 0. 5 percent of carbon emissions. And the Internet overall is reducing greenhouse gas emissions
So high-energy data centers that pay their utilities a premium for renewable power unnecessarily tie up low-carbon electrons that might otherwise be used to reduce emissions from other customers.
#Graphene onion rings have delicious potentialconcentric hexagons of graphene grown in a furnace at Rice university represent the first time anyone has synthesized graphene nanoribbons on metal from the bottom up--atom by atom.
One carbon atom latches onto the seed in a process called nucleation and others follow to form the familiar chicken-wire grid.
The edge lets carbon atoms get under the graphene skin where they start a new sheet.
But because the top graphene grows so fast it eventually halts the flow of carbon atoms to the new sheet underneath.
The mechanism relies on that top layer to stop carbon from reaching the bottom so easily Tour said.
The Tour lab pioneered the bulk manufacture of single-atom-thick graphene nanoribbons in 2009 with the discovery that carbon nanotubes could be unzipped chemically into long thin sheets.
versus carbon and get entirely new structures. This is dramatically different from regular graphene. Graduate student Zheng Yan a member of Tour's lab and lead author of the paper discovered the new route to nanoribbons
They may also be suitable for lithium storage for advanced lithium ion batteries he said.
The scientists also grew an oat variety unable to produce normal levels of avenacin a compound that protects roots from fungal pathogens.
He also studied the structure of the tomato peels to assess their efficiency as biomaterials to remove toxic metal ions and organic pollutants from water.
Zirconium loaded apple peels were found to be able to extract anions such as phosphate arsenate arsenite and chromate ions from aqueous solutions.
Rainforests that previously contained lots of big old trees which store carbon and support a diverse ecosystem are being replaced with oil palm or timber plantations or hollowed out by logging.
However this new research shows that enriched levels of nitrogen-15 a stable isotope abundant in manure have been found in the charred cereal grains
The research is based on stable carbon and nitrogen isotope analysis of 124 crop samples of barley wheat lentil and peas totalling around 2500 grains or seeds.
The charred remains represent harvested crops preserved in Neolithic houses destroyed by fire. The samples were from archaeological excavations of Neolithic sites across Europe dating from nearly 6000 to 2400 BC.
Archaeologists rely on the stable isotope analysis of the skeletal remains to establish a signature which provides information about what people once ate.
The heavier stable isotope of nitrogen-15 found in manure mimics the isotopic effect of a diet rich in meat and milk.
The crop nitrogen isotope analysis suggests that early farmers in Europe used their manure strategically as a resource that was limited by the number of animals they owned
#Broadband photodetector for polarized lightusing carpets of aligned carbon nanotubes researchers from Rice university and Sandia National Laboratories have created a solid-state electronic device that is hardwired to detect polarized light across a broad swath of the visible and infrared spectrum.
In February Kono L onard and colleagues described a new method for making photodetectors from carpets of carbon nanotubes--long narrow tubes of pure carbon that are about as wide as a strand of DNA.
Particle size has bioaccessibility of the energy of the food that is being consumed said Dr. Richard Mattes (CQ) professor of foods and nutrition at Purdue University West Lafayette Ind.
The study found with fewer chews the larger particles were eliminated by the body. With more chews the smaller particles were absorbed more readily into the system.
If the goal is to include food that is enjoyable and contribute protein a whole almond is probably the way you want to go Mattes said.
Dr Evropi Theodoratou of the University of Edinburgh's School of Molecular Genetic and Population Health Sciences said:
The first IBEX images released in 2009 showed an unexpected ribbon of surprisingly high energetic neutral atom (ENA) emissions circling the upwind side of the solar system.
If they become more efficient at using water they should be able to take more carbon out of the atmosphere due to higher growth rates.
When Keenan Richardson and colleagues began to examine those records they found that forests were storing more carbon
When electricity passes through a layer of silicon oxide it strips away oxygen molecules and creates a channel of pure metallic phase silicon that is less than five nanometers wide.
#Plant molecular biologist are getting to the root of the matterworking to identify key genes in the root development of poplar trees three Michigan Technological University scientists have come up with a new model for how genes interact
Wei a molecular biologist also has extensive knowledge of computer science and he is adept at applying it to large biological data sets.
#Not-weak knots bolster carbon fiberlarge flakes of graphene oxide are the essential ingredient in a new recipe for robust carbon fiber created at Rice university.
The material could be used to increase the strength of many products that use carbon fiber like composites for strong light aircraft or fabrics for bulletproof apparel according to the researchers.
That never happens in a carbon fiber or polymer fibers. Credit goes to the unique properties of graphene oxide flakes created in an environmentally friendly process patented by Rice a few years ago.
But they're massive compared with the petroleum-based pitch used in current carbon fiber.
The pitch particles are two nanometers in size which makes our flakes about ten thousand times larger said Rice graduate student Changsheng Xiang lead author of the new paper.
Unlike pitch the atom-thick flakes have an enormous surface area and cling to each other like the scales on a fish when pulled into a fiber.
Tour said industrial carbon fibers--a source of steel-like strength in ultralight materials ranging from baseball bats to bicycles to bombers--haven't improved much in decades
But the new carbon fibers spun at room temperature at Rice already show impressive tensile strength and modulus and have the potential to be even stronger when annealed at higher temperatures.
Heating the fibers to about 2100 degrees Celsius the industry standard for making carbon fiber will likely eliminate the knotting strength Xiang said
#Second door discovered in war against mosquito-borne diseasesin the global war against disease-carrying mosquitoes scientists have believed long that a single molecular door was the key target for insecticide.
Our discovery of a second receptor in the mosquitoes'sodium channel gives us a better understanding of how the insecticide works at a molecular level as well as could lead to ways to stem mosquitoes'resistance to pyrethroids.
At the molecular level resistance appears as mutations in the primary receptor in the sodium channel that allow mosquitoes to survive exposure to the insecticide.
Dr. Nommsen-Rivers and her colleagues were able to use a noninvasive method to capture mammary gland RNA--a chain of molecules that are blueprints for making specified proteins--in samples of human breast milk.
Dr. Nommsen-Rivers and her colleagues were able to use a noninvasive method to capture mammary gland RNA--a chain of molecules that are blueprints for making specified proteins--in samples of human breast milk.
although no differences were found in the quantity of toxic compounds such as cadmium which were detected also in very low concentrations.
and surface water quality handling floodwater preventing erosion and storing carbon). They focused on the Yahara River watershed
flood regulation pasture and freshwater supply all went together as did forest recreation soil retention carbon storage and surface water quality.
By measuring radioactive carbon-14 deposited in tusks and teeth by open-air nuclear bomb tests the method reveals the year an animal died
which is shaped a graph roughly like an inverted V--showing changes in carbon-14 levels in the atmosphere
The carbon-14 was formed in the atmosphere by U s. and Soviet atmospheric nuclear weapons tests in Nevada and Siberia from 1952 through 1962.
How the Study Was Performedneutrons from the nuclear tests bombarded nitrogen--the atmosphere's most common gas--to turn some of it into carbon-14.
and animal carbon-14 levels followed by a steady decline ever since. The method in the study is a bit like telling a tree's age by its rings but instead of counting rings Cerling Uno and colleagues measured carbon-14 levels at various points along the lengths of elephants'and hippos'tusks
and teeth. The conventional way of measuring carbon-14 is to wait for and count when the isotope decays radioactively.
In the study the researchers used accelerator mass spectrometry or AMS which requires 1000 times less material for analysis--a big advantage
when sampling fossils or small pieces of worked ivory Cerling says. In AMS the material being analyzed is bombarded with cesium atoms
which sputters off carbon atoms so the ratio of carbon-14 to carbon-12 can be measured.
The researchers tested the accuracy of carbon-14 dating in 29 animal and plant tissues killed and collected on known dates from 1905 to 2008.
and from Misha an African elephant euthanized in 2008 due to declining health at Utah's Hogle Zoo in Salt lake city. The analysis revealed that various tissues that formed at the same time have the same carbon-14 levels
By determining carbon-14 in these samples of known dates the researchers now can measure carbon-14 levels in other ivory to determine its age within about a year.
The four oldest samples--from animals died between 1905 and 1953--had minimal carbon-14
So the test can identify pre-1955 ivory by its low pre-nuclear-test levels of carbon-14.
It takes about 5700 years for half of carbon-14 to decay radioactively. But the amount in Earth's atmosphere after the 1950s and 1960s bomb tests faded much more quickly
because oceans and trees absorb carbon dioxide--including carbon-14--from the atmosphere. So the method won't work for tusks
or other tissues that grow after about 15 years from now when atmospheric carbon-14 returns to pre-bomb levels.
what prehistoric and modern animals ate over time especially when combined with existing isotope analysis of ratios of carbon-13 to carbon-12 in teeth--data that reveal
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