58,800 research outputs found
Weedy adaptation in Setaria spp.: IX. Effects of salinity, temperature, light and seed dormancy on Setaria faberi seed germination
Life in salty habitats is a function of tolerance to those chemicals at all
critical phases of a plant's life history. The ability to withstand salt as an
established plant may require different mechanisms and plant traits than those
needed to germinate in salty soils. Seeds establishing themselves in high salt
content may respond differently depending on the light conditions and seed
germinability at the time of salty water imbibition. S. faberi seed (and S.
viridis and S. pumila) plants were discovered thriving along the seacoasts of
Southern Japan. These plants possess the ability to after-ripen, germinate,
emerge and establish themselves, grow and reproduce in the salty soils and
salt-laden atmospheres present in these windy habitats. The objectives of this
paper are to determine the effect of salt (NaCl) in water imbibed by S. faberi
seed during after-ripening and germination, as well temperature and light.
Observations made also provide insights on the possible relationship between
salt and drought tolerance. Seed germination of all phenotypes inhibited by two
percent or more of NaCl. The effects of lesser amounts of NaCl on each of the
three phenotypes was highly dependent on the specific temperature and light
conditions. The three test phenotypes provided a good range to detect responses
to salinity, allowing the observation of both stimulatory and inhibitory
responses.Comment: 11 pages, 1 tabl
Effects of Fermion Flavor on Exciton Condensation in Double Layer Systems
We use fermionic path integral quantum Monte Carlo to study the effects of
fermion flavor on the physical properties of dipolar exciton condensates in
double layer systems. We find that by including spin in the system weakens the
effective interlayer interaction strength, yet this has very little effect on
the Kosterlitz-Thouless transition temperature. We further find that, to obtain
the correct description of screening, it is necessary to account for
correlation in both the interlayer and intralayer interactions. We show that
while the excitonic binding cannot completely surpress screening by additional
fermion flavors, their screening effectiveness is reduced leading to a much
higher transition temperatures than predicted with large-N analysis.Comment: 4 pages, 3 figure
Modelling alternative strategies for delivering hepatitis B vaccine in prisons : the impact on the vaccination coverage of the injecting drug user population
Since 2001 hepatitis B vaccination has been offered to prisoners on reception into prisons in
England and Wales. However, short campaigns of vaccinating the entire population of individual
prisons have achieved high vaccination coverage for limited periods, suggesting that short
campaigns may be a preferable way of vaccinating prisoners. A model is used that describes the
flow of prisoners through prisons stratified by injecting status to compare a range of vaccination
scenarios that describe vaccination on prison reception or via regular short campaigns. Model
results suggest that vaccinating on prison reception can capture a greater proportion of the
injecting drug user (IDU) population than the comparable campaign scenarios (63% vs. 55 . 6%
respectively). Vaccination on prison reception is also more efficient at capturing IDUs for
vaccination than vaccination via a campaign, although vaccination via campaigns may have a
role with some infections for overall control
Random vibration (stress screening) of printed wiring assemblies
The results of a random vibration test screening (RVSS) study of the determination of the upper and lower vibration limits on printed wiring assemblies (PWA) are summarized. The study results are intended to serve as a guide for engineers and designers who make decisions on PWA features that need to withstand the stresses of dynamic testing and screening. The maximum allowable PWA deflection, G levels, and PSD levels are compared to the expected or actual levels to determine if deleterious effects will occur
A 100 kW experimental wind turbine: Simulation of starting, overspeed, and shutdown characteristics
The ERDA/NASA 100 kW experimental wind turbine is modeled on a digital computer in order to study the performance of a wind turbine under operating conditions. Simulation studies of starting, overspeed, and shutdown performance were made. From these studies operating procedures, precautions, and limitations are prescribed
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A computer system to perform structure comparison using TOPS representations of protein structure
We describe the design and implementation of a fast topology–based method
for protein structure comparison. The approach uses the TOPS topological representation
of protein structure, aligning two structures using a common discovered
pattern and generating measure of distance derived from an insert score. Heavy
use is made of a constraint-based pattern matching algorithm for TOPS diagrams
that we have designed and described elsewhere Gilbert et al. (1999). The comparison
system is maintained at the European Bioinformatics Institute and is available
over the Web via the at tops.ebi.ac.uk/tops. Users submit a structure description in
Protein Data Bank (PDB) format and can compare it with structures in the entire
PDB or a representative subset of protein domains, receiving the results by email
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