14,578 research outputs found
Affirmative Action In Brazil: Its Recent Developments And The Argument For A Narrow Federalism Doctrine
Affirmative Action In Brazil: Its Recent Developments And The Argument For A Narrow Federalism Doctrine
Neonatal growth of Steller sea lion (Eumetopias jubatus) pups in Alaska
The growth rate of Steller sea lion (Eumetopias jubatus) pups was studied in southeast Alaska, the Gulf of Alaska, and the Aleutian Islands during the first six weeks after birth. The Steller sea lion population is currently stable in southeast Alaska but is declining in the Aleutian Islands and parts of the Gulf of Alaska. Male pups (22.6 kg [±2.21 SD]) were significantly heavier than female pups (19.6 kg [±1.80 SD]) at 1−5 days of age, but there were no significant differences among rookeries. Male and female pups grew (in mass, standard length, and axillary girth) at the same rate. Body mass and standard length increased at a faster rate for pups in the Aleutian Islands and the western Gulf of Alaska (0.45−0.48 kg/day and 0.47−0.53 cm/day, respectively) than in southeast Alaska (0.23 kg/day and 0.20 cm/day). Additionally, axillary girth increased at a faster rate for pups in the Aleutian Islands (0.59 cm/ day) than for pups in southeast Alaska v(0.25 cm/day). Our results indicate a greater maternal investment in male pups during gestation, but not during early lactation. Although differences in pup growth rate occurred among rookeries, there was no evidence that female sea lions and their pups were nutritionally stressed in the area of population declin
Stability of Impurities with Coulomb Potential in Graphene with Homogeneous Magnetic Field
Given a 2-dimensional no-pair Weyl operator with a point nucleus of charge Z,
we show that a homogeneous magnetic field does not lower the critical charge
beyond which it collapses.Comment: J. Math. Phys. (in press
Reciprocal interactions between the bark beetle-associated yeast Ogataea pini and host plant phytochemistry
Here we report the first experiments testing reciprocal effects between the bark beetle-associated yeast, Ogataea pini, and phytochemicals present in tree tissues (Pinus ponderosa). We tested two hypotheses: (i) tree phytochemicals mediate O. pin,i growth and (ii) O. pini affects chemical composition of plant tissues. We tested six monoterpenes on O. pins biomass growth in vitro and found that most monoterpenes inhibited O. pini growth; however mean O. pini biomass increased 21.5% when treated with myrcene and 75.5% when treated with terpinolene, relative to control. Ogataea pini was grown on phloem tissue ex vivo to determine whether O. pini affected phloem chemistry. Monoterpene concentrations declined in phloem over time, but phloem colonized by O. pini had significantly different concentrations of monoterpenes at two periods than phloem with no yeast. After 7 d, when O. pini was present, concentrations of the monoterpene Delta-3-carene was 42.9% lower than uncolonized phloem and concentrations of the monoterpene terpinolene was 345.0% higher than uncolonized phloem. After 15 d phloem colonized by O. pini had 505.4% higher concentrations of a-pinene than uncolonized phloem. These experiments suggest that O. pini responds to phytochemicals present in host tissues and the presence of O. pini might alter the chemical environment of phloem tissues during the early stages of beetle development. The interactions between O. pini and phytochemicals in pine vascular tissues might have consequences for the bark beetle that vectors O. pini, Dendroctonus brevicomis
Phase and micromotion of Bose-Einstein condensates in a time-averaged ring trap
Rapidly scanning magnetic and optical dipole traps have been widely utilised
to form time-averaged potentials for ultracold quantum gas experiments. Here we
theoretically and experimentally characterise the dynamic properties of
Bose-Einstein condensates in ring-shaped potentials that are formed by scanning
an optical dipole beam in a circular trajectory. We find that unidirectional
scanning leads to a non-trivial phase profile of the condensate that can be
approximated analytically using the concept of phase imprinting. While the
phase profile is not accessible through in-trap imaging, time-of-flight
expansion manifests clear density signatures of an in-trap phase step in the
condensate, coincident with the instantaneous position of the scanning beam.
The phase step remains significant even when scanning the beam at frequencies
two orders of magnitude larger than the characteristic frequency of the trap.
We map out the phase and density properties of the condensate in the scanning
trap, both experimentally and using numerical simulations, and find excellent
agreement. Furthermore, we demonstrate that bidirectional scanning eliminated
the phase gradient, rendering the system more suitable for coherent matter wave
interferometry.Comment: 10 pages, 7 figure
Determining the influence and effects of manufacturing variables on sulfur dioxide cells
A survey of the Li/SO2 manufacturing community was conducted to determine where variability exists in processing. The upper and lower limits of these processing variables might, by themselves or by interacting with other variables, influence safety, performance, and reliability. A number of important variables were identified and a comprehensive design experiment is being proposed to make the proper determinations
Cofinement, entropy, and single-particle dynamics of equilibrium hard-sphere mixtures
We use discontinuous molecular dynamics and grand-canonical transition-matrix
Monte Carlo simulations to explore how confinement between parallel hard walls
modifies the relationships between packing fraction, self-diffusivity, partial
molar excess entropy, and total excess entropy for binary hard-sphere mixtures.
To accomplish this, we introduce an efficient algorithm to calculate partial
molar excess entropies from the transition-matrix Monte Carlo simulation data.
We find that the species-dependent self-diffusivities of confined fluids are
very similar to those of the bulk mixture if compared at the same,
appropriately defined, packing fraction up to intermediate values, but then
deviate negatively from the bulk behavior at higher packing fractions. On the
other hand, the relationships between self-diffusivity and partial molar excess
entropy (or total excess entropy) observed in the bulk fluid are preserved
under confinement even at relatively high packing fractions and for different
mixture compositions. This suggests that the partial molar excess entropy,
calculable from classical density functional theories of inhomogeneous fluids,
can be used to predict some of the nontrivial dynamical behaviors of fluid
mixtures in confined environments.Comment: submitted to JC
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