39,002 research outputs found
Comparing Hemp Seed Yields (Cannabis sativa L.) of an On-Farm Scientific Field Experiment to an On-Farm Agronomic Evaluation Under Organic Growing Conditions in Lower Austria
Hemp seed yields of the variety Fedora-19 in an on-farm scientific field experiment on small plots and in an on-farm evaluation in 11 hemp fields under practical organic growing conditions in Lower Austria were compared to give a realistic view of the variability of yields. Dry matter seed yields from the on-farm field experiment ranged from 127 to 143 g/m2. Under practical growing conditions, yields ranged from 34 to 151 g/m2 in the sample plots. The reported hemp seed yield after combine harvesting, drying, and cleaning was between 324 kg/ha and 717 kg/ha. The results of the experiment show that harvesting by hand considerably influences yields. Yields of the manual harvest in sample plots indicate a high correlation with yields harvested by the combine harvester (R2 = 0.91). The commercial yield is 71% of the yields recorded in sample plots in the fields. Our data questions the transfer of results and conclusions drawn from the data of scientific field experiments that employ manual harvest to that of practical circumstances, and support the notion of on-farm research
Measuring the Decorrelation Times of Fourier Modes in Simulations
We describe a method to study the rate at which modes decorrelate in
numerical simulations. We study the XY model updated with the Metropolis and
Wolff dynamics respectively and compute the rate at which each eigenvector of
the dynamics decorrelates. Our method allows us to identify the decorrelation
time for each mode separately. We find that the autocorrelation function of the
various modes is markedly different for the `local' Metropolis compared to the
`non-local' Wolff dynamics. Equipped with this new insight, it may be possible
to devise highly efficient algorithms.Comment: 16 pp (LaTeX), PUPT-1378 , IASSNS-HEP-93/
Hemp (Cannabis sativa L.) as a Resource for Green Cosmetics: Yield of Seeds and Fatty Acids Composition of 20 Varieties under the Growing Conditions of Organic Farming in Austria
The interest in hemp (non-drug Cannabis sativa L.) for skin care and cosmetic use is due to the high content of oil, especially unsaturated fatty acids in seed with technological and therapeutic effects. In a field trial on an organic farm, seed weight and content of fatty acids of 20 hemp varieties were surveyed on three different harvest dates. The dry matter seed yields ranged from 27-149 g m2. The varieties Ferimon-12, Fedora-19, and Bialobreszie produced high seed yields on all three harvest dates but yields were not significantly different from a large group of other varieties. Contents of palmitic acid range from 3.1 to 4.1%, of stearic acid from 0.1 to 1.9%, of oleic acid from 3.7 to 9.2%, of linoleic acid from 44.8 to 60.2%, of α-linolenic acid from 18.2 to 27.4%, and of γ-linolenic acid from 1.6 to 4.7%. The genotype has no significant influence on fatty acid content. All 20 varieties tested show high quantities of fatty acid depending on the harvest date, so that no variety can be favored. Results confirm that hemp is a very good source of fatty acids for skin care and cosmetic use
Modulation of internuclear communication in multinuclear Ruthenium(II) polypyridyl complexes
The syntheses and characterisation of a series of mononuclear and dinuclear ruthenium polypyridyl complexes based on the bridging ligands 1,3-bis-[5-(2-pyridyl)-1H-1,2,4-triazol-3-yl]benzene, 1,4-bis-[5-(2-pyridyl)-1H-1,2,4-triazol-3-yl]benzene, 2,5-bis-[5-(2-pyridyl)-1H-1,2,4-triazol-3-yl]thiophene, 2,5-bis-[5-pyrazinyl-1H-1,2,4-triazol-3-yl]thiophene are reported. Electrochemical studies indicate that in these systems, the ground state interaction is critically dependent on the nature of the bridging ligand and its protonation state, with strong and weak interactions being observed for thiophene- and phenylene-bridged complexes, respectively
Radio Astronomical Polarimetry and the Lorentz Group
In radio astronomy the polarimetric properties of radiation are often
modified during propagation and reception. Effects such as Faraday rotation,
receiver cross-talk, and differential amplification act to change the state of
polarized radiation. A general description of such transformations is useful
for the investigation of these effects and for the interpretation and
calibration of polarimetric observations. Such a description is provided by the
Lorentz group, which is intimately related to the transformation properties of
polarized radiation. In this paper the transformations that commonly arise in
radio astronomy are analyzed in the context of this group. This analysis is
then used to construct a model for the propagation and reception of radio
waves. The implications of this model for radio astronomical polarimetry are
discussed.Comment: 10 pages, accepted for publication in Astrophysical Journa
Studies on processing, particle formation, and immunogenicity of the HIV-1 gag gene product: a possible component of a HIV vaccine
Antigens in a particulate conformation were shown to be highly immunogenic in mammals. For this reason, the particle forming capacity of derivatives of the HIV-1 group specific core antigen p55 gag was assayed and compared dependent on various expression systems: recombinant bacteria, vaccinia- and baculoviruses were established encoding the entire core protein p55 either in its authentic sequence or lacking the myristylation consensus signal. Moreover, p55 gag was expressed in combination with the protease (p55-PR) or with the entire polymerase (p55-pol), respectively. Budding of 100-160 nm p55 core particles, resembling immature HIV-virions, was observed in the eucaryotic expression systems only. In comparison to the vaccinia virus driven expression of p55 in mammalian cells, considerably higher yields of particulate core antigen were obtained by infection of Spodoptera frugiperda (Sf9) insect cells with the recombinant Autographa californica nuclear polyhedrosis (AcMNPV) baculovirus. Mutation of the NH2-terminal myristylation signal sequence prevented budding of the immature core particles. Expression of the HIV p55-PR gene construct by recombinant baculovirus resulted in complete processing of the p55 gag precursor molecule in this system. The introduction of an artificial frameshift near the natural frameshift site resulted in constitutive expression of the viral protease and complete processing of p55, both in Escherichia coli and in vaccinia virus infected cells. Interestingly, significant processing of p55 resembling that of HIV infected H9 cells could also be achieved in the vaccinia system by fusing the entire pol gene to the gag gene. Moreover, processing was not found to be dependent on amino-terminal myristylation of the gag procursor molecule, which is in contrast to observations with type C and type D retrovirus. However, complete processing of p55 into p24, p17, p9 and p6 abolished particle formation. Purified immature HIV-virus like particles were highly immunogenic in rabbits, leading to a strong humoral immune response after immunization. Empty immature p55 gag particles represent a noninfectious and attractive candidate for a basic vaccine component
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