The research team of Annette Rompel from the Institute for Biophysical Chemistry University of Vienna explore the mechanisms behind the browning reaction during the spoilage of mushrooms.
This precursor is activated then via specific chemical cleavage. At this cleavage site the protein segment covering part of the enzyme active site is removed
and the substrates (tyrosine and other monophenols) can be accessed and take part in key chemical reactions. New Method of Isolation and unique reagent leads to successnone of the previously established methods of isolation present in the literature could be applied successfully for PPO4.
For the first time at the Institute for Biophysical Chemistry of the University of Vienna a method was developed that allows for the one stage isolation of latent tyrosinase from their natural source.
The enzyme characterization was undertaken at the Department of chemistry with close cooperation with the Institute of Mass Spectrometry lead by Andreas Rizzi both within the University of Vienna.
After sufficiently large quantities were extracted from pure PPO4 the researchers were able to identify and optimize appropriate crystallization conditions
which produced well formed protein crystals. This was only possible with the use of a relatively unusual co-crystallization reagent a polyoxometalate of the Anderson type.
Integral for medicine and biotechnologythe Phd student Stephan Mauracher worked at the University of Vienna taking an essential part in this project as part of the University Initiative termed Functional Molecules.
Following this research it has been made possible to purify the enzyme in sufficient quantities for characterization.
Ulrich Kortz working at the Jacobs University of Bremen was responsible for synthesizing the polyoxometalate used
and was a key proponent of its usage as an additive for protein crystallization. The research project was continued then as FWF Initiative.
This research has allowed for the crystallization and three-dimensional structure of PPO4 to be resolved says Anette Rompel.
Physicists find 2-D form pays no heed to defectsdefects damage the ideal properties of many two-dimensional materials like carbon-based graphene.
In a paper in the American Chemical Society journal Nano Letters the Rice team analyzed the properties of elemental bonds between semiconducting phosphorus atoms in 2-D sheets.
these metal compounds have also been considered for electronics because of their inherent semiconducting properties. In pristine dichalcogenides atoms of the two elements alternate in lockstep.
But wherever two atoms of the same element bond they create a point defect. Think of it as a temporary disturbance in the force that could slow electrons down Yakobson said.
Semiconductors are the basic element of modern electronics that direct and control how electrons move through a circuit.
or grain boundaries--where sheets of a 2-D material merge at angles forcing like atoms to bond--the materials become far less useful.
But at an angle phosphorus reveals its true form as alternate atoms jut out of the matrix.
The researchers also show it may be possible to tune the electronic properties of 2-D phosphorus by altering (aka doping) it with foreign atoms.
Carbon and zinc may boost positive conductivity while potassium may increase negative conductivity; the researchers believe phosphorus may be a promising anode material for batteries.
Yakobson is Rice's Karl F. Hasselmann Professor of Materials Science and Nanoengineering a professor of chemistry and a member of Rice's Richard E. Smalley Institute for Nanoscale Science and Technology.
and land use changes and for calculating carbon balances. Story Source: The above story is provided based on materials by Helmholtz Centre For Environmental Research-UFZ.
#Agricultural revolution in Africa could increase global carbon emissionsproductivity-boosting agricultural innovations in Africa could lead to an increase in global deforestation rates
and carbon emissions a Purdue University study finds. Historically improvements in agricultural technology have conserved land and decreased carbon emissions at the global level:
Gaining better yields in one area lessens the need to clear other areas for crops sidestepping a land conversion process that can significantly raise the amount of carbon dioxide released into the atmosphere.
and raising greenhouse gas emissions said Thomas Hertel a distinguished professor of agricultural economics. Increasing productivity in Africa--a carbon-rich region with low agricultural yields--could have negative effects on the environment especially
if agricultural markets are integrated highly he said. This study highlights the importance of understanding the interplay between globalization and the environmental impacts of agricultural technology.
Some researchers suggest that increasing the profitability of farming will amplify its negative environmental effects raising greenhouse gas emissions and accelerating tropical deforestation.
Hertel and fellow researchers Navin Ramankutty and Uris Baldos developed a novel economic framework to analyze the effects of regional improvements in agricultural technology on global rates of land use and carbon emissions.
and diminish carbon emissions compared with an alternative scenario without crop innovations. The global effects of a green revolution in Africa however are less certain Hertel said.
If the future global economy remains as fragmented as it has been historically--a world of very distinct agricultural markets--then a green revolution in Africa will lower global carbon emissions he said.
But if markets become more integrated faster agricultural innovation in Africa could raise global carbon emissions in the coming decades.
4 million acres) and global carbon emissions by 267 million metric tons. The sharp differences between the global impacts of a prospective African green revolution and those of previous green revolutions can be traced to several factors Hertel said.
The area converted would likely be carbon intensive and have a low emissions efficiency--that is crop yields would be low relative to the carbon emissions released by converting the land to crops.
But the potential negative effects of an African green revolution will diminish over time Hertel said.
and decrease carbon emissions especially if yields improved quickly. The most carbon-rich land however should be protected immediately from conversion to cropland he said.
We need to prevent regions in Africa that are rich in carbon and biodiversity from being cleared for agriculture to avoid increasing emissions he said.
Boosting yields brings many benefits but increasing global food supplies while minimizing the environmental footprint of agriculture remains a major challenge.
& Environmental Studies (F&es) reports that large-scale forest losses during the last 150 years have reduced global emissions of biogenic volatile organic compounds (BVOCS)
which control the atmospheric distribution of many short-lived climate pollutants such as tropospheric ozone methane and aerosol particles.
carbon storage and the albedo effect. The lost carbon storage capacity caused by forest conversion has exacerbated global warming.
Meanwhile the disappearance of dark-colored forests has helped also offset temperature increases through the so-called albedo effect.
and increased albedo may have entirely offset the warming caused by the loss of forest-based carbon storage capacity.
and grasslands and replaced them with croplands said Unger an assistant professor of atmospheric chemistry at F&es.
Not all of these compounds affect atmospheric chemistry in the same way. Aerosols for instance contribute to global cooling
However reductions in the potent greenhouse gases methane and ozone--which contribute to global warming--have helped deliver a net cooling effect.
But a study published last year by Unger showed that emissions of these volatile compounds have decreased indeed.
In particular the GEDI data will provide us with global-scale insights into how much carbon is being stored in the forest biomass.
By revealing the 3-D architecture of forests in unprecedented detail GEDI will provide crucial information about the impact that trees have on the amount of carbon in the atmosphere.
Although it is established well that trees absorb carbon and store it long-term scientists have not quantified exactly how much carbon forests contain.
As a result it's not possible to determine how much carbon would be released if a forest were destroyed nor how well emissions could be countered by planting new trees.
One of the most poorly quantified components of the carbon cycle is the net balance between forest disturbance
and internal structure of the forest at the fine scale required to accurately estimate their carbon content said Bryan Blair the deputy principal investigator for GEDI at Goddard.
and in turn how much carbon they are storing. By combining these findings with spatially comprehensive maps from other satellites showing where development
Glycine soja used to improve protein content in soybean; and Vitis amurensis a wild relative of grape which has been used to improve cold tolerance.
The bacteria produce a myriad of active antimicrobial compounds. These lactic acid bacteria have now been tested on severe human wound pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) Pseudomonas aeruginosa and vancomycin-resistant Enterococcus (VRE) among others.
Fats and proteins tend to increase with the economic development of emerging countries he said.
#Dietary recommendations may be tied to increased greenhouse gas emissionsif Americans altered their menus to conform to federal dietary recommendations emissions of heat-trapping greenhouse gases tied to agricultural production could increase significantly according to a new study
Martin Heller and Gregory Keoleian of U-M's Center for Sustainable Systems looked at the greenhouse gas emissions associated with the production of about 100 foods as well as the potential effects of shifting Americans to a diet
while keeping caloric intake constant diet-related greenhouse gas emissions would increase 12 percent. If Americans reduced their daily caloric intake to the recommended level of about 2000 calories
while shifting to a healthier diet greenhouse gas emissions would decrease by only 1 percent according to Heller and Keoleian.
A paper by Heller and Keoleian titled Greenhouse gas emission estimates of U s. dietary choices and food loss is scheduled for online publication Sept. 5 in the Journal of Industrial Ecology.
In its 2010 dietary guidelines USDA recommends that Americans eat more fruits vegetables whole grains fat-free and low-fat dairy products and seafood.
They should consume less salt saturated fat trans fat cholesterol added sugar and refined grains.
While a drop in meat consumption would help cut diet-related greenhouse gas emissions increased use of dairy products
In the United states in 2010 food production was responsible for about 8 percent of the nation's greenhouse gas emissions.
In general animal-based foods are responsible for more greenhouse gas emissions per pound than plant-based foods.
The production of both beef cattle and dairy cows is tied to especially high levels of greenhouse gas emissions.
and their manure also releases this potent greenhouse gas. Greenhouse gas emissions associated with producing the U s. diet are dominated by the meats category according to Heller and Keoleian.
While beef accounts for only 4 percent by weight of the food available it contributes 36 percent of the associated greenhouse gases they conclude.
The U-M researchers found that a switch to diets that don't contain animal products would lead to the biggest reductions in this country's diet-related greenhouse emissions.
and how it contributes to U s. greenhouse gas emissions. They concluded that annual emissions tied to uneaten food are equivalent to adding 33 million passenger vehicles to the nation's roads.
#Coffee genome sheds light on the evolution of caffeinethe newly sequenced genome of the coffee plant reveals secrets about the evolution of man's best chemical friend:
and flavonoid compounds which contribute to qualities such as coffee aroma and the bitterness of beans.
Scientists theorize that the chemical may help plants repel insects or stunt competitors'growth. One recent paper showed that pollinators--like humans--may develop caffeine habits.
but it does reinforce the idea that the compound is a valuable asset. It also provides the opportunity to better understand the evolution of coffee's genome structure.
when nitrogen oxides carbon monoxide and volatile organic compounds react with sunlight after the chemicals'release from vehicles industry or burning of wood or other plant or animal matter.
Catching greenhouse gases with advanced membranesresearchers in Japan have engineered a membrane with advanced features capable of removing harmful greenhouse gases from the atmosphere.
Their findings published in The british journal Nature Communications may one day contribute to lower greenhouse gas emissions and cleaner skies.
Greenhouse gases originating from industrial processes and the burning of fossil fuels blanket Earth and are the culprits behind current global warming woes.
which up 84%of the United State's greenhouse gases in 2012 and can linger in Earth's atmosphere for up to thousands of years.
Therefore new low-cost technologies are needed sorely to incentivize greenhouse gas capture by industry. Easan Sivaniah--an associate professor at Kyoto University's Institute for Integrated Cell-Material sciences (icems)--led an international team of researchers from icems
and the University of Cambridge to create an advanced membrane capable of rapidly separating gases.
and cavities less than 2 nm in diameter that can trap gases of interest once they enter said Qilei Song who was involved in the study.
To overcome PIM-1's weaknesses Sivaniah's team heated PIM-1 at temperatures ranging from 120 to 450 °C in the presence of oxygen a process referred to as thermal oxidation.
PIM-1 can also be used for other applications such as capturing carbon dioxide from the burning of fossil fuels enriching the oxygen content in air for efficient combustion engines hydrogen gas production
which makes them unsuitable for molecular analysis . However they suggest attempting to secure new samples for further study which may provide further insight into their relationship to other organisms.
and biology its chemical ecology and the types of damage it does to various host plants.
They also discuss different chemical control options that can be used successfully in integrated pest management programs.
To return to an integrated approach to managing all pests in the crops affected by H. halys growers require a more sustainable strategy for chemical control that combines efficient use of insecticides with a better understanding of its biology and behavior according to the authors.
and found that the contents of protein fat vitamins and minerals are the same as that of commercial yeast.
and poorthe quality of the U s. diet showed some modest improvement in the last decade in large measure because of a reduction in the consumption of unhealthy trans fats
For fruits vegetables whole grains nuts and legumes long-chain omega-3 fats and polyunsaturated fatty acids (PUFAS) a higher score corresponded to higher intake.
For trans fat sugar-sweetened beverages and fruit juices red and/or processed meat and sodium a higher score corresponded to lower intake.
and food processing especially the reduction of trans fat intake that were motivated likely by both public policy and nutrition education.
Results indicated that it pays off to maintain chemical free greenhouse crop production. If biological pest control was used whitefly populations were more susceptible to insecticides
--if current trends continue--food production alone will reach if not exceed the global targets for total greenhouse gas (GHG) emissions in 2050.
This will come at a high price warn the authors as the deforestation will increase carbon emissions as well as biodiversity loss
%This will put emissions from food production alone roughly equal to the target greenhouse gas emissions in 2050 for the entire global economy.
if achieved might mitigate some of the greenhouse gases causing climate change. There are basic laws of biophysics that we cannot evade said lead researcher Bojana Bajzelj from the University of Cambridge's Department of Engineering who authored the study with colleagues from Cambridge's departments of Geography and Plant sciences as well as the University of Aberdeen's Institute of Biological
and releasing more greenhouse gases. Agricultural practices are not necessarily at fault here --but our choice of food is said Bajzelj.
Yield gap closure alone still showed a greenhouse gas increase of just over 40%by 2050.
and halving food waste still showed a small increase of 2%in greenhouse gas emissions. When healthy diets were added the model suggests that all three measures combined result in agricultural GHG levels almost halving from their 2009 level--dropping 48%.
We tested a scenario where all countries were assumed to achieve an average balanced diet--without excessive consumption of sugars fats and meat products.
Documenting carbon sequestration in Borneoit's that time of year again--the dry season in southeastern Asia when the Haze Wave begins.
Deforestation from an ill-fated plan to convert nearly 2. 5 million acres of Kalimantan peat swamp forest into rice paddies has contributed to Indonesia becoming the third-largest emitter of carbon according to professor Mark Cochrane a senior scientist at the Geospatial
and modeling to help the Indonesian Forest Research and development Agency assess the progress being made to reduce carbon emissions from Borneo's ancient peat swamp forest.
He collaborates with carbon emissions expert Robert Yokelson a chemistry professor from the University of Montana.
The grant is part of NASA's global carbon monitoring program which is part of an international focus on reducing emissions due to deforestation.
and releases carbon. Once the logging companies completed their work the indigenous people and a host of new settlers were left to figure out how to survive in this altered environment.
Cochrane estimates that the peat contains 20 times as much carbon as the forest trees themselves did.
and degradation or REDD offers monetary rewards to countries that reduce their carbon emissions according to Cochrane.
However progress in carbon sequestration must be documented by a third party he explains. That's the challenge:
which will allow a third party to reliably estimate how much carbon is being lost and subsequently how that number has decreased over time he explains.
Up to 200 different gases may be escaping through these fires but no method currently exists to accurately determine the composition of peat fire emissions.
and there were many more changes in the non-coding part of the genome than in the parts of the genome that codes for protein.
Recent studies of fat intake and diabetes incidence support the notion that eating the right kind of fats is beneficial to health.
When people started eating less fat they compensated by eating more refined carbohydrates which stimulate insulin secretion and increase fat deposition.
The Joslin nutritional guidelines for diabetes recommend a diet with relatively high amounts of healthy fats and protein but moderately low amounts of carbohydrates.
The work reported this month in the Journal of the American Chemical Society (JACS) focused on a tetracycline discovered in 2008 by scientists who isolated small amounts from penicillium fungi.
We're inspired by molecules that are biologically active and have the potential to become medicines one day he said.
The new discovery belongs to a class of antibiotics known as tetracyclines for their distinctive molecular structure.
To find new weapons especially against superbugs that resist nearly all antibiotics synthetic chemists pursue the complex process of mimicking the structures of effective natural molecules as they build drug candidates atom by atom.
and the chemotherapy agent calicheamicin said the complicated new molecule offered a challenge he couldn't resist.
The structure (the discoverers) assigned to this molecule was suspicious to us. We didn't actually believe that it was correct he said.
Given this we initiated a research program to synthesize this compound for three purposes he said.
One was to develop new synthetic chemistry which is always the case in these kinds of endeavors.
Two was to synthesize the molecule itself and confirm its structure. Three was to use the technology we've developed to make analogs of it in the hope that we could find something simpler and yet better in terms of its biological and pharmacological properties.
and did indeed revise the structure of the molecule. The lab turned synthetic samples over to biologist Shamoo and his group for testing against a number of bacterial strains and comparison with natural viridicatumtoxin B. This was very exciting for us said Nicolaou who moved his lab from the Scripps Research Institute
In order to investigate the biological properties of our synthesized compounds we turned to the Shamoo laboratory for its expertise in the area of antibiotics and drug-resistant bacteria.
The results also suggested the possibility of making variants by modifying certain domains of the molecule to improve its overall pharmacological properties.
It's said that for a drug to be discovered a chemist has to make 10000 compounds on average he said.
The interface between chemistry and biology is the key to success in discovering drugs. Co-authors of the JACS paper are graduate students Christopher Hale Lizanne Nilewski and Kathryn Beabout and postdoctoral fellows Christian Nilewski Heraklidia Ioannidou and Abdelatif El Marrouni all of Rice
Nicolaou is the Harry C. and Olga K. Wiess Professor of Chemistry. Story Source: The above story is provided based on materials by Rice university.
Areas with carbon-rich ecosystems with key wilderness habitats such as tropical forests were identified as those where new roads would cause the most environmental damage with the lease human benefit particularly areas where few roads currently exist.
when the plant gets a chemical signal from the bacterium --but the growing tube inside the root hair that accepts the bacteria requires something else
This dual requirement for chemical and mechanical signals is present in both associations even though the association between rhizobia and legumes is only 60 million years old.
The gene called OSCA1 encodes a protein in the cell membrane of plants that senses changes in water availability
But until now the molecular machinery that plants use to send this signal --and monitor water availability in general--remained unknown.
Pei and Duke colleagues Fang Yuan James Siedow and others identified a gene that encodes a protein in the cell membranes of plant leaves
Instead the scientists used samples of cheetah hair to determine the stable isotope ratios of carbon and nitrogen.
whose photosynthesis contains intermediate products with three carbon atoms (C3). In contrast grasses exhibit a C4 photosynthesis. These food webs can be differentiated with the help of the involved carbon isotopes.
Herbivores typically only belong to one food web and the isotope ratio hence deposits in their body tissue.
Small antelopes such as springbok or steenbok specialise on shrubs and herbs whereas the oryx antelope feeds on grass--just like the cattle.
One step up in the food chain the isotope ratio of the prey transfers to its predator.
An organic residue analysis using mass spectrometry revealed that all of the relatively uniform jars contained chemical compounds indicative of wine.
and Food Chemistry could help prevent organic food fraud. Researchers from the Bavarian Health and Food safety Authority and the Wuerzburg University note that the demand for organic food is growing at a rapid clip.
Currently the most reliable authentication technique analyzes the stable isotope composition of nitrogen but it is not foolproof.
They looked to a technique called nuclear magnetic resonance spectroscopy which has been used to authenticate foods including honey and olive oil.
The above story is provided based on materials by American Chemical Society. Note: Materials may be edited for content and length.
#Greenhouse gases: New group of soil microorganisms can contribute to their eliminationinra research scientists in Dijon have shown that the ability of soils to eliminate N2o can mainly be explained by the diversity
Nitrous oxide (N2o) is one of the principal greenhouse gases alongside carbon dioxide (CO2) and methane (CH4;
This elimination can be achieved by microorganisms living in the soil that are able to reduce N2o into nitrogen (N2) the gas that makes up around four-fifths of the air we breathe and
Unlike other greenhouse gases such as carbon dioxide (CO2) or methane (CH4) the ability of soils to eliminate N2o
and thus act as a sink for this greenhouse gas has been studied very little hitherto. Their work has shown that this variability is linked to a new group of N2o-consuming microorganisms.
Pebble-size particles may jumpstart planet formationrocky planets like Earth start out as microscopic bits of dust tinier than a grain of sand
Astronomers using the National Science Foundation's (NSF) Green Bank Telescope (GBT) have discovered that filaments of star-forming gas near the Orion Nebula may be brimming with pebble-size particles--planetary building blocks 100
If confirmed these dense ribbons of rocky material may well represent a new mid-size class of interstellar particles that could help jumpstart planet formation.
The new GBT observations extend across the northern portion of the Orion Molecular Cloud Complex a star-forming region that includes the famed Orion Nebula.
In particular since the particles are more efficient than expected at emitting at millimeter wavelengths the grains are very likely to be at least a millimeter and possibly as large as a centimeter across or roughly the size of a small Lego-style building block.
Due to the unique environment in the Orion Molecular Cloud Complex the researchers propose two intriguing theories for their origin.
These regions compared to molecular clouds in general have lower temperatures higher densities and lower velocities--all of
The second scenario is that the rocky particles originally grew inside a previous generation of cores or perhaps even protoplanetary disks.
The material could then have escaped back into the surrounding molecular cloud rather than becoming part of the original newly forming star system.
and planets but if we can confirm these results it would add a new population of rocky particles to interstellar space.
These data were compared with earlier studies as well as temperature estimates obtain from observations of ammonia molecules in the clouds.
and there could be other explanations for the bright signature we detected in the emission from the Orion Molecular Cloud concluded Brian Mason an astronomer at the NRAO
Since it contains one of the highest concentrations of protostars of any nearby molecular cloud it will continue to excite the curiosity of astronomers.
MUSTANG-1. 5 the even more-sensitive successor to MUSTANG and ARGUS a camera designed for mapping the distribution of organic molecules in space.
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