4,661 research outputs found
Boden, Wurzeln, Präparate
Die biodynamischen Präparate verbessern auch Wurzelwachstum und Wurzelgesundheit. Werden sie abweichend von der Anleitung mit anderen als mit tierischen Hüllen hergestellt, ist das Endprodukt nicht vergleichbar. Erst die antagonistischen Wirkungen der Präparatezutaten ermöglichen ihre spezielle, ausgleichende Wirkung
Isolation and amino acid sequence analysis of a 4,000-dalton dynorphin from porcine pituitary
A 4,000-dalton dynorphin was isolated from porcine pituitary. It has 32 amino acids (Mr = 3,986), with the previously described heptadecapeptide (now called dynorphin A) at its amino terminus and a related tridecapeptide, dynorphin B, at its carboxyl terminus. The two peptides are separated by the "processing signal" Lys-Arg
BIOPHYSICAL CONSTRAINTS AND ECOLOGICAL COMPATIBILITIES OF DIVERSE AGROECOSYSTEMS
International audienceA diagnostic approach based on multi-scale integrated analysis and model simulations was employed to identify specific or common biophysical constraints, technological changes and ecological compatibilities of the diverse subsistence (SUB) and organic (ORG) agro-ecosystems in the Fertile Crescent (FC) of West Asia and the organic and conventional (CNV) agro-ecosystem in the Northern Corn Belt (NCB) and Northern Great Plains (NGP) of the U.S. For each agro-ecosystem, soil carbon, total yield, temporal yield variance and yield coefficient of variation per crop rotation were used as sustainability indicators. Thresholds of technologies necessary for the proper functioning and flow of agro-ecosystem services were identified under the most-likely IPCC-projected climate change scenarios for the next 30 years. The carbon budgets of agro-ecosystems were largely related to the choice of crops, crop sequence, and length of the crop rotation, and were influenced by external inputs, tillage system and removal of crop residues. Carbon depletion is expected to be less in organic and subsistence agro-ecosystems when nitrogen-fixing legumes are included in more diverse crop rotations and when crop residues are incorporated into the soil. Potential nutrients loss to the environment was significantly larger in conventional systems, and nutrients are expected to be depleted over time in subsistence- faster than in organically-managed soils. Optimal and sustainable agricultural intensification is feasible through agroecosystem diversification and the proper integration of genetic and natural resources management. In all agroecosystems, for more diverse rotations to be adopted at a large scale, there needs to be large and easily accessible markets for the additional product
Improving farm nutrient management by optimizing organic matter inputs and root health
Farmer cooperators conducted strip trials to help investigators create a nutrient and organic matter budgeting system that offered whole farm management guidelines to tighten nitrogen budgets for corn. Corn root health also was analyzed
How Maize Evolves When It Is Bred Under Biodynamic/Organic Conditions And Selected For Improved Nutritional Value And Nitrogen Efficiency.
"A breeding program for maize for biodynamic/organic farmers has taken place in at the Mandaamin Institute. The program began in 1989 and entails summer nurseries in Wisconsin, USA and winter nurseries in Puerto Rico and Chile. Emphasis has been on improving adaptation, productivity, nutritional value, and nitrogen (N) efficiency/N2 fixation. Methods include pedigree breeding , development of synthetic populations, and selection under N limited conditions. A co-evolutionary approach is taken to optimize interactions between the maize populations, the breeder, and associated microbes, under N limited biodynamic/organic environments . Results have been shifts in protein quality and better adaptation to N limited conditions. Emergent evolutionary processes a) increased the occurrence of mutants with soft grain possessing higher protein quality; b) improved chlorophyll content and N efficiency, and c) resulted in the appearance of densely branched rooting systems in the top layers of the soil for N efficient inbreds and hybrids. Grain yields for the best hybrids have been competitive with conventionally bred hybrids, especially under N limited conditions. Grain quality of the resulting hybrids averaged 16 % more protein, 30 % more methionine, and 16 % more lysine than for conventional hybrids. Under poultry feeding conditions where some synthetic methionine is fed, the monetary value of the grain was 14 % higher because it reduced the need for soymeal in feed. Outcomes of the program are populations, inbreds, and hybrids which are now in wider spread strip plot testing on organic farms in Wisconsin, Illinois, Indiana, and have entered initial commercial production in conjunction with Foundation Organic Seed (Onalaska, WI). We will also report results from ongoing farm trials that assess relationships between rooting, N uptake, N mineralization of organic matter, N2 fixation, and protein production in grain.
Communications Biophysics
Contains research objectives and reports on one research project.U.S. Air Force under Contract AF19(604)-411
Physical Models of Noncovalent Interactions Involving Aromatic Rings
Noncovalent interactions involving π-systems play a vital role throughout
chemical and biological processes. These π-interactions can be found in organic
photovoltaics and electronics as well as govern many protein and DNA interactions. A
fundamental and physically meaningful model of these interactions is necessary for the
efficient exploitation of these materials and rational drug design. First, the role of
aromaticity in π-stacking, cation/π, and anion/π interactions is investigated. Aromaticity
weakly hinders π-stacking and greatly hinders anion/π interactions, while greatly
enhancing cation/Ï€ interactions. Nonaromatics, therefore, present themselves as a new
target in design for π-stacking and anion/π interactions.
The well-established local direct interaction model for π-stacking that substituent
effects are due solely to local electrostatic changes has also been expanded herein. First,
we show that the local direct model for substituent effects in π-stacking also applies to
polar XH/Ï€ interactions. The nonpolar XH/Ï€ interactions vary little with substituent,
depending only on changes in dispersion. The energetic changes of both sets of XH/Ï€
interactions follow well-known substituent constants. Next, the local direct interaction
model is expanded to the use of electric fields to reconcile unusual similarity in the
substituent effects between benzene, triazine, and borazine. Substituent effects for
different rings are similar as long as the electric fields of those rings are similar in the
location of the substituent. In fact, the substituent effect scales proportionally to the relative strength of those fields. Lastly, in an analysis on anion/Ï€ complexes with a variety of azines and benzene, it is shown that changes induced through the substitution of a carbon-hydrogen bond with nitrogen are almost exclusively from the nuclear charge differences. This reconciles well with the local direct interaction model
Thermodynamic perturbation theory for associating fluids with small bond angles: Effects of steric hindrance, ring formation, and double bonding
We develop a comprehensive approach to model associating fluids with small bond angles using Wertheim's
perturbation theory. We show theoretically and through Monte Carlo simulations that as bond angle is varied
various modes of association become dominant. The theory is shown to be in excellent agreement with Monte
Carlo simulation for the prediction of the internal energy, pressure, and fractions in rings and chains, double
bonded over the full range of bond angles
Calibration of NIRS Whole Grain Analyzers for Amino Acid Measurement in Corn
In food and feed products, near infrared spectroscopy (NIRS) is used to measure an increasing number of chemical parameters that have traditionally been measured by analytical chemistry. The use of NIRS is driven by its speed and relative low cost, thereby allowing users to accurately measure nutrient components and other factors of interest in a matter of seconds versus several hours or days for traditional lab results. Calibration of NIRS analyzers relies on good representative sample sets and consistent reference chemistry; calibration is, in itself, a painstaking process but, once done, accurate calibrations provide rapid, reliable measurements in daily operations
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