In the online journal elife a large international group of scientists led by investigators at the Salk Institute for Biological Studies have traced the thousands of genes in a plant that are activated once ethylene a gas that acts as a plant
or make plants more resistant to disease says the senior investigator Joseph R. Ecker head of Salk's Plant Molecular and Cellular Biology laboratory.
and proteins involved in each of these branch pathways and this might help us manipulate the discrete functions this hormone regulates Ecker says.
I have been trying for several decades to understand how a simple gas--two carbons and four hydrogens--can cause such profound changes in a plant Ecker says.
Now we can see that by altering the expression of one protein ethylene produces cascading waves of gene activation that profoundly alters the biology of the plant.
what happens in Arabidopsis after ethylene gas causes activation of EIN3 a master transcription factor--a protein that controls gene expression--that Ecker had discovered
EIN3 and a related protein EIL1 are required for the response to ethylene gas; without these proteins ethylene has no effect on the plant.
We wanted to know how ethylene is actually doing its job Ecker says. Once the plant responds to ethylene by activating EIN3
We found that about half of the genomic targets of the EIN3 protein are found in other hormone signaling pathways.
Logging may have greater impact on carbon emissions than previously thoughtusing wood for energy is considered cleaner than fossil fuels
but a Dartmouth College-led study finds that logging may release large amounts of carbon stored in deep forest soils.
Global atmospheric studies often don't consider carbon in deep (or mineral) soil because it is thought to be stable
But the Dartmouth findings show deep soil can play an important role in carbon emissions in clear-cutting and other intensive forest management practices.
and that forest carbon analyses are incomplete unless they include deep soil which stores more than 50 percent of the carbon in forest soils.
Our paper suggests the carbon in the mineral soil may change more rapidly and result in increases in atmospheric carbon dioxide as a result of disturbances such as logging said Dartmouth Professor Andrew Friedland a co-author.
Our paper suggests that increased reliance on wood may have unintended the effect of increasing the transfer of carbon from the mineral soil to the atmosphere.
So the intended goal of reducing carbon in the atmosphere may not be met. The federal government is looking to wood wind solar hydropower
and other renewable energy sources to address concerns about climate change and energy security. Woody biomass which includes trees grown on plantations managed natural forests
Mineral soil carbon responses can vary highly depending on harvesting intensity surface disturbance and soil type.
and understanding forest carbon cycles requires an in depth analysis of the storage in and fluxes among different forest carbon pools
and biomass harvesting on elemental cycling processes in high-elevation forests in the Northeastern United states. He considers many elements including carbon trace elements such as lead and major elements such as nitrogen and calcium.
and phosphorus (P) attached to soil particles. But no-till requires herbicides to control weeds
Some chemicals were associated also with fewer changes in fetal heart rate which normally parallel fetal movements.
The blood samples were tested for levels of 11 pesticides and 36 polychlorinated biphenyl (PCB) compounds. According to the findings all participants had detectable concentrations of at least one-quarter of the analyzed chemicals
despite the fact that they have been banned for more than three decades. Fetal heart rate effects were observed not consistently across all of the compounds analyzed;
when effects were seen higher chemical exposures were associated with reductions in fetal heart rate accelerations an indicator of fetal wellbeing.
However associations with fetal motor activity measures were more consistent and robust: higher concentrations of 7 of 10 organochlorine compounds were associated positively with one of more measures of more frequent and more vigorous fetal motor activity.
These chemicals included hexachlorobenzene DDT and several PCB congeners. Women of higher socioeconomic status in the study had a greater concentration of chemicals compared to the women of lower socioeconomic statusthere is tremendous interest in how the prenatal period sets the stage for later child development.
These results show that the developing fetus is susceptible to environmental exposures and that we can detect this by measuring fetal neurobehavior.
This is yet more evidence for the need to protect the vulnerable developing brain from effects of environmental contaminants both before
Successes and failures from the first billion acressince 1996 farmers worldwide have planted more than a billion acres (400 million hectares) of genetically modified corn and cotton that produce insecticidal proteins from the bacterium
Bt proteins used for decades in sprays by organic farmers kill some devastating pests but are considered environmentally friendly and harmless to people.
However some scientists feared that widespread use of these proteins in genetically modified crops would spur rapid evolution of resistance in pests.
Same pest same crop same Bt protein but very different outcomes. He explained that in the southwestern U s. scientists from the EPA academia industry
Semiconducting films for atom-thick circuitsscientists at Rice university and Oak ridge National Laboratory (ORNL) have advanced on the goal of two-dimensional electronics with a method to control the growth of uniform atomic layers of molybdenum disulfide (MDS.
if large high-quality atomically thin MDS sheets could be grown in a chemical vapor deposition (CVD) furnace
Graphene and hbn are flat with arrays of hexagons formed by their constituent atoms. But while MDS looks hexagonal
when viewed from above it is actually a stack with a layer of molybdenum atoms between two layers of sulfur atoms.
and carbon atoms would bind. We're working on it he said. We would like to stick graphene
Our microscopy facility at ORNL allows us to see materials in a way they've never been seen before--down to the level of individual atoms.
Ajayan is the Benjamin M. and Mary Greenwood Anderson Professor in Engineering and a professor of mechanical engineering and materials science chemistry and chemical and biomolecular engineering.
Yakobson is the Karl F. Hasselmann Professor of Mechanical engineering and Materials Science and a professor of chemistry.
and climate models we can understand how increased greenhouse gases in the atmosphere along with temperature increases and precipitation changes will affect wheat yield globally.
#Roman seawater concrete holds the secret to cutting carbon emissionsthe chemical secrets of a concrete Roman breakwater that has spent the last 2000 years submerged in the Mediterranean sea have been uncovered by an international team of researchers led by Paulo Monteiro of the U s
But making it releases carbon from burning fuel needed to heat a mix of limestone and clays to 1450 degrees Celsius (2642 degrees Fahrenheit)--and from the heated limestone (calcium carbonate) itself.
Cutting greenhouse gas emissions is one powerful incentive for finding a better way to provide the concrete the world needs;
Yet Roman harbor installations have survived 2000 years of chemical attack and wave action underwater. How the Romans did made itthe Romans concrete by mixing lime and volcanic rock.
The seawater instantly triggered a hot chemical reaction. The lime was hydrated--incorporating water molecules into its structure
--and reacted with the ash to cement the whole mixture together. Pozzuoli Bay defines the northwestern region of the Bay of Naples.
In concrete made with Portland cement this is a compound of calcium silicates and hydrates (C-S-H). Roman concrete produces a significantly different compound with added aluminum and less silicon.
The resulting calcium-aluminum-silicate-hydrate (C-a-S-H) is an exceptionally stable binder. At ALS beamlines 5. 3. 2. 1 and 5. 3. 2. 2 x-ray spectroscopy showed that the specific way the aluminum substitutes for silicon in the C-a-S-H
may be the key to the cohesion and stability of the seawater concrete. Another striking contribution of the Monteiro team concerns the hydration products in concrete.
and less release of carbon into the atmosphere may be the legacy of a deeper understanding of how the Romans made their incomparable concrete.
Unrealistic expectations regarding bioenergy can result in failing to achieve the target of reducing greenhouse gases.
whose career has been spent examining the archaeological data developing the chemical analyses and following the trail of the Eurasian grapevine (Vitis vinifera) in the wild and its domestication by humans this confirmation of the earliest evidence of viniculture in France is a key step in understanding the ongoing development of what he calls the wine culture of the world
What we haven't had is clear chemical evidence combined with botanical and archaeological data showing how wine was introduced into France
Combined Archaeological Chemical and Archaeobotanical Evidence Corroborate Discoveryat the site of Lattara merchant quarters inside a walled settlement circa 525-475 BCE held numerous Etruscan
After sample extraction ancient organic compounds were identified by a combination of state-of-the-art chemical techniques including infrared spectrometry gas chromatography-mass spectrometry solid phase microextraction ultrahigh-performance liquid chromatography
tandem mass spectrometry and one of the most sensitive techniques now available used here for the first time to analyze ancient wine
and grape samples liquid chromatography-Orbitrap mass spectrometry. All the samples were positive for tartaric acid/tartrate (the biomarker
and wine in the middle East and Mediterranean) as well as compounds deriving from pine tree resin. Herbal additives to the wine were identified also including rosemary basil and/or thyme
Alcoholic beverages in which resinous and herbal compounds are more easily put into solution were the principle medications of antiquity.
and expansion of a worldwide wine culture--one that has known its earliest roots in the ancient Near east circa 7000-6000 BCE with chemical evidence for the earliest wine at the site of Hajji Firiz in what is now northern
In four new studies of carbon isotopes in fossilized tooth enamel from scores of human ancestors and baboons in Africa from 4 million to 10000 years ago a team of two dozen researchers found a surprise
The isotope method cannot distinguish what parts of grasses and sedges human ancestors ate--leaves stems seeds and-or underground storage organs such as roots or rhizomes.
What You Eatthe new studies analyze carbon isotope results from 173 teeth from 11 species of hominins.
but the new studies include new carbon-isotope results for 104 teeth from 91 individuals of eight hominin species. Those teeth are in African museums
The method of determining ancient creatures'diets from carbon isotope data is less than 20 years old
The powder was placed in a mass spectrometer to learn ratios of carbon isotopes incorporated into tooth enamel via diet.
The ratios of rare carbon-13 to common carbon-12 reveal whether an animal ate plants that used so-called C3 C4
Animals eating C4 and CAM plants have enriched amounts of carbon-13. C3 plants include trees bushes and shrubs and their leaves and fruits;
and the University of California at Davis. The study published online in the American Chemical Society journal Environmental science
and Kansas. They also used estimates of carbon dioxide a greenhouse gas and other elements from a number of models including the government's well-tested Environmental Policy Integrated Climate (EPIC) model.
Researchers at the Max Planck Institute for Chemical Ecology Jena Germany discovered that the ability of Manduca sexta moths to recognize changes in the profile of volatile compounds released by plants being attacked by Manduca caterpillars allows them to lay their eggs on plants that are less likely
but enzymes released by M. sexta caterpillars'spit change some of these molecules into (E)- 2-hexenyl acetate
which has the same chemical composition but a different structure. The resulting changes in the volatile profile alerts Geocoris bugs to the presence of M. sexta caterpillars on the plant their potential prey.
Ideal conditions for Manduca offspringnow the scientists from the Max Planck Institute for Chemical Ecology show another interesting effect of the chemical odor conversion:
The above story is provided based on materials by Max Planck Institute for Chemical Ecology. Note: Materials may be edited for content and length.
The expansion will mark Jove's eighth journal section after the recent additions of Jove Chemistry and Applied Physics.
Graphene consists of a single atomic layer of carbon arranged in a honeycomb lattice. Our first Science paper in 2008 studied the strength graphene can achieve
This our second Science paper reports on the strength of large-area graphene films grown using chemical vapor deposition (CVD)
In its perfect crystalline form graphene (a one-atom-thick carbon layer) is the strongest material ever measured as the Columbia Engineering team reported in Science in 2008--so strong that as Hone observed it would take an elephant balanced on a pencil to break through a sheet
Currently scientists can grow sheets of graphene as large as a television screen by using chemical vapor deposition (CVD) in
In studying the processing techniques used to create their samples for testing they found that the chemical most commonly used to remove the copper substrate also causes damage to the graphene severely degrading its strength.
or ultrastrong composites that could replace carbon fiber. Or the researchers speculate a science fiction idea of a space elevator that could connect an orbiting satellite to Earth by a long cord that might consist of sheets of CVD graphene
since graphene (and its cousin material carbon nanotubes) is the only material with the high strength-to-weight ratio required for this kind of hypothetical application.
This is due to all the atoms in graphene being surface atoms so surface damage that would normally not degrade the strength of 3d materials can completely destroy the strength of 2d materials.
The bacterial diversity in the cloaca of each bird could be estimated with the aid of molecular genetic techniques.
The differences may correlate with changes in the birds'gut chemistry over time or with changes in diet
#Dairys carbon footprint: Flatulence tops the listresearchers at the University of Arkansas are attempting to help the U s. dairy industry decrease its carbon footprint as concentrations of carbon dioxide in Earth's atmosphere reach record levels.
In 2007 Americans consumed approximately 17.4 million metric tons of fluid milk--milk consumed as a drink
The dairy industry has set a goal of 25 percent reduction in greenhouse gas emissions by 2020.
and wastethe researchers found that for every kilogram of milk consumed in the United states per year 2. 05 kilograms of greenhouse gases on average are emitted over the entire supply chain to produce process
The greenhouse gases were measured as carbon dioxide equivalents and included methane refrigerants and other gases that trap radiation.
The largest contributors were feed production enteric methane--gas emitted by the animal itself --and manure management.
which is natural gas that is otherwise lost to the atmosphere he said. At the processor and distribution level greater emphasis on truck fleet-fuel usage
Their study was published as a special issue Carbon and Water Footprint of U s. Milk From Farm to Table of the International Dairy Journal in April.
and soft wood) with ultrasound consistently enhances the chemical reactions necessary to convert the biomass into high-value fuels and chemicals.
Lignin is the chemical compound that binds cellulose and hemicellulose together in plant cell walls. Commonly enzymes or chemicals are used to remove it from biomass
and allow the freed sugars to be dissolved for further processing into biofuel. Grewell and his colleagues found that pretreating
The Iowa State team replaced the initial steaming with ultrasound sonically smashing the corn into tiny particles in the same way physicians use ultrasound to shatter kidney stones.
Grewell and his colleagues report a third application for ultrasound in biofuel production showing that they can accelerate transesterification the main chemical reaction for converting oil to biodiesel.
To take the temperature of the past we rely on indirect evidence like oxygen isotope ratios in the fossil shells of marine organisms
#Land-based carbon offsets: False hope? Forest and soil carbon is important, but does not offset fossil fuel emissionsleading world climate change experts have thrown cold water on the idea that planting trees can offset carbon dioxide emissions from fossil fuels.
Professor Brendan Mackey of Griffith University Climate Change Response Program is the lead author of an international study involving researchers from Australia
and the U k. Their findings are reported in Untangling the confusion around land carbon science and climate change mitigation policy published in the scientific journal Nature Climate Change.
and internationally assume that fossil fuel emissions can be offset through sequestering carbon by planting trees and other land management practices.
There is a danger in believing that land carbon sinks can solve the problem of atmospheric carbon emissions
The photovoltaic devices created in a project led by Rice chemical engineer Rafael Verduzco and Penn State chemical engineer Enrique Gomez are based on block copolymers self-assembling organic materials that arrange themselves into distinct layers.
They easily outperform other cells with polymer compounds as active elements. The discovery is detailed online in the American Chemical Society journal Nano Letters.
While commercial silicon-based solar cells turn about 20 percent of sunlight into electricity and experimental units top 25 percent there's been an undercurrent of research into polymer-based cells that could greatly reduce the cost
of solar energy Verduzco said. The Rice/Penn State cells reach about 3 percent efficiency but that's surprisingly better than other labs have achieved using polymer compounds.
You need two components in a solar cell: one to carry (negative) electrons the other to carry positive charges Verduzco said.
Verduzco is an assistant professor of chemical and biomolecular engineering. The National Science Foundation the Department of energy the Welch Foundation the Shell Center for Sustainability and the Louis and Peaches Owen Family Foundation supported the research.
and neuroscience and director of the Institute for Genomic Biology at the University of Illinois. And finding that it's Egr with all that this gene is known to do in vertebrates provides another demonstration that some of the molecular mechanisms underlying behavioral plasticity
Derek Meyers a doctoral student in physics at the U of A found that the way electrons form in superconductive material--known as the Zhang-Rice singlet state--was present in a chemical compound that is very different
#Despite safety and other concerns, nuclear power saves lives, greenhouse gas emissions, experts sayglobal use of nuclear power has prevented about 1. 84 million air pollution-related deaths
and release of 64 billion tons of greenhouse gases that would have resulted from burning coal and other fossil fuels a new study concludes.
and prevent emission of 80-240 billion tons of the greenhouse gases linked to global warming the study found.
By contrast we assess that large-scale expansion of unconstrained natural gas use would not mitigate the climate problem
If the role of nuclear power declines significantly in the next 20-30 years Kharecha added the International Energy Agency predicts that achieving the major reductions in greenhouse gas emissions that are required to mitigate climate change would require heroic achievements in the use
of emerging low-carbon technologies which have yet to be proven. Story Source: The above story is provided based on materials by American Chemical Society.
Note: Materials may be edited for content and length. Journal Reference e
#Despite safety and other concerns, nuclear power saves lives, greenhouse gas emissions, experts sayglobal use of nuclear power has prevented about 1. 84 million air pollution-related deaths
and release of 64 billion tons of greenhouse gases that would have resulted from burning coal and other fossil fuels a new study concludes.
It appears in the ACS journal Environmental science & Technology. Pushker A. Kharecha and James E. Hansen state that nuclear power has the potential to help control both global climate change
and prevent emission of 80-240 billion tons of the greenhouse gases linked to global warming the study found.
By contrast we assess that large-scale expansion of unconstrained natural gas use would not mitigate the climate problem
If the role of nuclear power declines significantly in the next 20-30 years Kharecha added the International Energy Agency predicts that achieving the major reductions in greenhouse gas emissions that are required to mitigate climate change would require heroic achievements in the use
of emerging low-carbon technologies which have yet to be proven. Story Source: The above story is provided based on materials by American Chemical Society.
Note: Materials may be edited for content and length. Journal Reference e
#Nordic diet lowers cholesterol, study findsa healthy Nordic diet lowers cholesterol levels and therefore the risk of cardiovascular disease a pan-Nordic study where Lund University participated has found.
The amount of harmful fat particles in the blood also declined says Lieselotte Cloetens a biomedical nutrition researcher at Lund University.
The density and chemical composition of the wood may provide clues to the climate and air composition in the past.
or gut environment than people who eat the more typicalwestern diet that is high in fat
The UCLA researchers are seeking to pinpoint particular chemicals produced by gut bacteria that may be triggering the signals to the brain.
The one-atom-thick form of carbon can act as a go-between that allows vertically aligned carbon nanotubes to grow on nearly anything.
when graphene is used as a middleman surfaces considered unusable as substrates for carbon nanotube growth now have the potential to do so.
By its very nature one-atom-thick graphene is all surface area. The same could be said of carbon nanotubes which are basically rolled-up tubes of graphene.
A vertically aligned forest of carbon nanotubes grown on diamond would disperse heat like a traditional heat sink but with millions of fins.
Such an ultrathin array could save space in small microprocessor-based devices. Further work along these lines could produce such structures as patterned nanotube arrays on diamond that could be utilized in electronic devices Ajayan said.
To test their ideas the Honda team grew various types of graphene on copper foil by standard chemical vapor deposition.
and hold the airborne iron-based catalyst particles from which the nanotubes grow. The researchers think graphene facilitates nanotube growth by keeping the catalyst particles from clumping.
Ajayan thinks the extreme thinness of graphene does the trick. In a previous study the Rice lab found graphene shows materials coated with graphene can get wet
but the graphene provides protection against oxidation. That might be one of the big things about graphene that you can have a noninvasive coating that keeps the property of the substrate
but stops the catalyst from aggregating. Testing found that the graphene layer remains intact between the nanotube forest and the diamond or other substrate.
Ajayan is the Benjamin M. and Mary Greenwood Anderson Professor in Mechanical engineering and Materials Science and of chemistry at Rice.
#Saturated fats do not yield better bacona recent paper published in the Journal of Animal Science suggests producers may want to adjust pig diets
Some producers believe that feeding pigs saturated fats will undo the fat-softening effects of DDGS.
Firmer fat means longer-lasting pork. But researchers from the University of Illinois found that including saturated fats in DDGS diets makes no difference in fat quality.
The researchers formulated six corn-soybean meal diets to test the effects of saturated fat additives on carcass fat quality in pigs.
Five of these diets contained DDGS. According to the researchers pork produced from pigs fed DDGS have reduced shelf life and increased susceptibility to oxidative damage.
and those fatty acids are deposited into the fat of the animal said Hans-Henrik Stein study co-author
According to Stein high levels of unsaturated fats make pork belly fat too soft to slice for bacon.
To counteract this problem producers have included saturated fats such as corn germ beef tallow palm kernel oil and glycerol in diets containing DDGS
in order to make the fat firmer. For this study corn germ beef tallow palm kernel oil and glycerol were added each to a diet containing DDGS.
The researchers compared the performance of pigs fed each of these diets to the performance of pigs fed a diet containing DDGS with no saturated fats added
and a control diet containing corn-soybean meal but no DDGS. Firmness of fat was tested by measuring the distance of belly flop.
This was done by draping the belly of the carcasses over a metal rod with the skin facing down.
The larger the distance was the firmer the fat. The researchers found that pigs fed the control diet containing no DDGS had greater belly flop distances than the pigs fed the other diets.
This led researchers to conclude that adding saturated fats to diets containing DDGS has no effect on the fat quality of pigs.
whether the type of exposure such as whether the compound was inhaled or absorbed through the skin
However our study suggests that the risk increases in a dose response manner as the length of exposure to these chemicals increases.
#KISS ME DEADLY proteins may help improve crop yieldsdartmouth College researchers have identified a new regulator for plant hormone signaling--the KISS
ME DEADLY family of proteins (KMDS)# that may help to improve production of fruits vegetables and grains.
Professor G. Eric Schaller the paper's senior author studies the molecular mechanisms by which a plant recognizes a hormone
Overtext Web Module V3.0 Alpha
Copyright Semantic-Knowledge, 1994-2011