953 research outputs found
The Special Obligation of the Sufferer
There are a number of inter-personal and intra-personal dynamics which affect/define the role of “sufferer” and that of the other encountering suffering. What follows is discussion regarding the role of each, and the paradoxical obligation of the beleaguered to assist in the management of their suffering through charity toward the other.
Emergence of common lambsquarters (Chenopodium album L.) is influenced by the landscape position in which seeds developed
In a 2-yr field study, we evaluated the emergence and early growth of Chenopodium album L. (common lambsquarters) seedlings as affected by the landscape position in which the seeds (i) developed, (ii) overwintered, and (iii) were planted. Results indicated that a higher proportion of seeds originating from lower slope positions emerged compared with seeds originating from the backslope or upper slope. The timing of emergence was the same for all seed source locations. There was no influence of overwintering location on weed emergence. Regardless of the seed source, we observed faster emergence and growth of C. album planted in the lower slope, where soil conditions were more conducive to growth. These experiments will support the development of new strategies and decision aids to improve weed management
Phase separation transition in liquids and polymers induced by electric field gradients
Spatially uniform electric fields have been used to induce instabilities in
liquids and polymers, and to orient and deform ordered phases of
block-copolymers. Here we discuss the demixing phase transition occurring in
liquid mixtures when they are subject to spatially nonuniform fields. Above the
critical value of potential, a phase-separation transition occurs, and two
coexisting phases appear separated by a sharp interface. Analytical and
numerical composition profiles are given, and the interface location as a
function of charge or voltage is found. The possible influence of demixing on
the stability of suspensions and on inter-colloid interaction is discussed.Comment: 7 pages, 3 figures. Special issue of the J. Phys. Soc. Ja
A new inorganic atmospheric aerosol phase equilibrium model (UHAERO)
A variety of thermodynamic models have been developed to predict inorganic gas-aerosol equilibrium. To achieve computational efficiency a number of the models rely on a priori specification of the phases present in certain relative humidity regimes. Presented here is a new computational model, named UHAERO, that is both efficient and rigorously computes phase behavior without any a priori specification. The computational implementation is based on minimization of the Gibbs free energy using a primal-dual method, coupled to a Newton iteration. The mathematical details of the solution are given elsewhere. The model computes deliquescence behavior without any a priori specification of the relative humidities of deliquescence. Also included in the model is a formulation based on classical theory of nucleation kinetics that predicts crystallization behavior. Detailed phase diagrams of the sulfate/nitrate/ammonium/water system are presented as a function of relative humidity at 298.15 K over the complete space of composition
A computationally efficient inorganic atmospheric aerosol phase equilibrium model (UHAERO)
A variety of thermodynamic models have been developed to predict inorganic gas-aerosol equilibrium. To achieve computational efficiency a number of the models rely on a priori specification of the phases present in certain relative humidity regimes. Presented here is a new computational model, named UHAERO, that is both efficient and rigorously computes phase behavior without any a priori specification. The computational implementation is based on minimization of the Gibbs free energy using a primal-dual method, coupled to a Newton iteration. The mathematical details of the solution are given elsewhere. The model also computes deliquescence and crystallization behavior without any a priori specification of the relative humidities of deliquescence or crystallization. Detailed phase diagrams of the sulfate/nitrate/ammonium/water system are presented as a function of relative humidity at 298.15 K over the complete space of composition
Dominance Relationships of Cycloheximide-Resistant Mutants of Schizophyllum commune Fr.
We have isolated several mutants of Schizophyllum commune Fr. able to grow on media containing cycloheximide in concentrations up to 30 mg/L. Genetic analyses of the resistant phenotypes show them to be due to the action of a single gene located on the first linkage group between the A-mating type factor and a gene for an adenine requirement (ade-ll). We have analyzed the growth and development of dikaryons made homoallelic for either the resistant or sensitive alleles as well as the heteroallelic dikaryon. These dikaryons showed different abilities to fruit when placed on media containing various concentrations of cycloheximide. Homoallelic sensitive strains failed to grow on any concentration of cycloheximide tested(\u3e 1 mg/L). Homoallelic resistant strains grew and fruited on all concentrations of cycloheximide up to 30 mg/ L. Heteroallelic dikaryons showed a response that was dose-dependent for fruiting, but not growth. As the concentration of cycloheximide was increased, these heteroallelic colonies showed a progressive loss of ability to form fruiting bodies and at concentrations greater than 30 mg/L, they gave rise to homokaryons as outgrowths from the colony edge. These homokaryons were all of the nuclear genotype associated with the original resistant component of the dikaryon
Fine-scale variability in iceberg velocity fields and implications for an ice-associated pinniped
Icebergs and sea ice found in proglacial fjords serve as important habitat for pinnipeds in polar and subpolar regions. Environmental forcings can drive dramatic changes in fjord ice coverage, with implications for pinniped distribution, abundance, and behavior. To better understand how pinnipeds respond to changes in iceberg habitat, we combine (i) iceberg velocity fields over hourly to monthly timescales, derived from high-rate time-lapse photogrammetry of Johns Hopkins Glacier and Inlet, Alaska, with (ii) aerial photographic surveys of harbor seals (Phoca vitulina richardi) conducted during the pupping (June) and molting (August) seasons. Iceberg velocities typically followed a similar diurnal pattern: flow was weak and variable in the morning and strong and unidirectional in the afternoon. The velocity fields tended to be highly variable in the inner fjord, across a range of timescales, due to changes in the strength and location of the subglacial outflow plume, whereas in the outer fjord the flow was more uniform and eddies consistently formed in the same locations. During the pupping season, seals were generally more dispersed across the slow moving portions of the fjord (with iceberg speeds 0.2 m s−1.. In contrast, during the molting season the seals were increasingly likely to be found on fast moving icebergs in or adjacent to the glacier outflow plume. Use of slow moving icebergs during the pupping season likely provides a more stable ice platform for nursing, caring for young, and avoiding predators. Periods of strong glacier runoff and/or katabatic winds may result in more dynamic and less stable ice habitat, with implications for seal behavior and distribution within the fjord
Shear Alignment and Instability of Smectic Phases
We consider the shear flow of well-aligned one-component smectic phases, such
as thermotropic smectics and lamellar diblock copolymers, below the critical
region. We show that, as a result of thermal fluctuations of the layers,
parallel () alignment is generically unstable and perpendicular ()
alignment is stable against long-wavelength undulations. We also find,
surprisingly, that both and are stable for a narrow window of values
for the anisotropic viscosity.Comment: To appear in PRL. Revtex, 1 figure
Testing Color Evaporation in Photon-Photon Production of J/Psi at CERN LEP II
The DELPHI Collaboration has recently reported the measurement of J/Psi
production in photon-photon collisions at LEP II. These newly available data
provide an additional proof of the importance of colored c bar{c} pairs for the
production of charmonium because these data can only be explained by
considering resolved photon processes. We show here that the inclusion of color
octet contributions to the J/Psi production in the framework of the color
evaporation model is able to reproduce this data. In particular, the
transverse-momentum distribution of the J/Psi mesons is well described by this
model.Comment: 10 pages, 5 Figures, Revtex
Racial Equity Considerations In Safe To Sleep Messaging: Learning From The Community
Black infants are dying at a rate of over twice that of White infants. We know that infants in unsafe sleep positions are more likely to die from Sudden Unexpected Infant Death (SUID). Safe to Sleep® education has led to a dramatic decrease in mortality among white infants, but over 60% of Black families do not follow the Safe to Sleep® parameters. Safe to Sleep® education is given to pregnant women during the prenatal period and prior to hospital discharge, but what is the best way to share this message with Black families
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