5,898 research outputs found
The Multiple Roles of Low Income, Minority Women in the Family and Community: A Qualitative Investigation
This longitudinal, ethnographic research study was incepted to investigate service use among families living in poor urban communities. Themes that emerged during data collection focus on the variety of roles played by women, in the home, and in the neighborhood. We identified numerous strengths exhibited by women, that is, roles that help families adapt and survive. Over a two-year period, we spent time with families, in their homes, and in their communities. Not only did the women fulfill multiple roles in the family, but they performed care taking functions within the community as well. A more complete understanding of family and community strengths will help researchers and social service professionals better serve diverse families
Spin Dependent Fragmentation Functions for Heavy Flavor Baryons and Single Heavy Hyperon Polarization
Spin dependent fragmentation functions for heavy flavor quarks to fragment
into heavy baryons are calculated in a quark-diquark model. The production of
intermediate spin 1/2 and 3/2 excited states is explicity included.
, and production rate and polarization at LEP energies are
calculated and, where possible, compared with experiment. A different approach,
also relying on a heavy quark-diquark model, is proposed for the small momentum
transfer inclusive production of polarized heavy flavor hyperons. The predicted
polarization is roughly in agreement with experiment.Comment: LaTeX2e 11 pages with 4 PostScript figures. To be published in
Proceedings of the International Workshop ``Symmetries and spin'',
Praha-SPIN-200
The Evolution of Cloud Cores and the Formation of Stars
For a number of starless cores, self-absorbed molecular line and column
density observations have implied the presence of large-amplitude oscillations.
We examine the consequences of these oscillations on the evolution of the cores
and the interpretation of their observations. We find that the pulsation energy
helps support the cores and that the dissipation of this energy can lead toward
instability and star formation. In this picture, the core lifetimes are limited
by the pulsation decay timescales, dominated by non-linear mode-mode coupling,
and on the order of ~few x 10^5--10^6 yr. Notably, this is similar to what is
required to explain the relatively low rate of conversion of cores into stars.
For cores with large-amplitude oscillations, dust continuum observations may
appear asymmetric or irregular. As a consequence, some of the cores that would
be classified as supercritical may be dynamically stable when oscillations are
taken into account. Thus, our investigation motivates a simple hydrodynamic
picture, capable of reproducing many of the features of the progenitors of
stars without the inclusion of additional physical processes, such as
large-scale magnetic fields.Comment: 12 pages, 7 figures, submitted to Ap
Recommended from our members
North American Influence on Tropospheric Ozone and the Effects of Recent Emission Reductions: Constraints from ICARTT Observations
We use observations from the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) campaign over eastern North America in summer 2004, interpreted with a global 3âD model of tropospheric chemistry (GEOSâChem), to improve and update estimates of North American influence on global tropospheric ozone and the effect of recent U.S. anthropogenic reductions on surface ozone pollution. We find that the 50% decrease in U.S. stationary NOx sources since 1999 has decreased mean U.S. boundary layer ozone concentrations by 6â8 ppbv in the southeast and 4â6 ppbv in the Midwest. The observed dO3/dCO molar enhancement ratio in the U.S. boundary layer during ICARTT was 0.46 mol molâ1, larger than the range of 0.3â0.4 from studies in the early 1990s, possibly reflecting the decrease in the NOx/CO emission ratio as well as an increase in the ozone production efficiency per unit NOx. North American NOx emissions during summer 2004 as constrained by the ICARTT observations (0.72 Tg N fossil fuel, 0.11 Tg N biomass burning, 0.28 Tg N lightning for 1 July to 15 August) enhanced the hemispheric tropospheric ozone burden by 12.4%, with comparable contributions from fossil fuel and lightning (5â6%), but only 1% from biomass burning emissions despite 2004 being a record fire year over Alaska and western Canada.Earth and Planetary Science
New instability of non-extremal black holes: spitting out supertubes
We search for stable bound states of non-extremal rotating three-charge black
holes in five dimensions (Cvetic-Youm black holes) and supertubes. We do this
by studying the potential of supertube probes in the non-extremal black hole
background and find that generically the marginally bound state of the
supersymmetric limit becomes metastable and disappears with non-extremality
(higher temperature). However near extremality there is a range of parameters
allowing for stable bound states, which have lower energy than the
supertube-black hole merger. Angular momentum is crucial for this effect. We
use this setup in the D1-D5 decoupling limit to map a thermodynamic instability
of the CFT (a new phase which is entropically dominant over the black hole
phase) to a tunneling instability of the black hole towards the supertube-black
hole bound state. This generalizes the results of ArXiv:1108.0411 [hep-th],
which mapped an entropy enigma in the bulk to the dual CFT in a supersymmetric
setup.Comment: 28 pages + appendix, 15 figures, v2: References added, typos
corrected. Version published in JHE
A (Running) Bolt for New Reasons
We construct a four-parameter family of smooth, horizonless, stationary
solutions of ungauged five-dimensional supergravity by using the
four-dimensional Euclidean Schwarzschild metric as a base space and
"magnetizing" its bolt. We then generalize this to a five-parameter family
based upon the Euclidean Kerr-Taub-Bolt. These "running Bolt" solutions are
necessarily non-static. They also have the same charges and mass as a
non-extremal black hole with a classically-large horizon area. Moreover, in a
certain regime their mass can decrease as their charges increase. The existence
of these solutions supports the idea that the singularities of non-extremal
black holes are resolved by low-mass modes that correct the singularity of the
classical black hole solution on large (horizon-sized) scales.Comment: 25 pages, 3 figures, LaTeX; v2: minor changes, references adde
Quantitative studies on the interaction of concanavalin A, the carbohydrate-binding protein of the jack bean, with model carbohydrate-protein conjugates
The interaction of concanavalin A with a comprehensive series of carbohydrate-bovine serum albumin comjugates was investigated by agar gel diffusion and quantitative precipitation techniques. These studies showed that when conjugated to bovine serum albumin, those sugars which inhibited concanavalin A-polysaccharide interaction formed a precipitate with concanavalin A. The unexpected reactivity of the p-phenylazo [ss]--glucopyranoside-bovine serum albumin conjugate is rationalized on the basis of inhibition data employing several aryl and alkylglycosides.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/33889/1/0000154.pd
The Nuts and Bolts of Einstein-Maxwell Solutions
We find new non-supersymmetric solutions of five-dimensional ungauged
supergravity coupled to two vector multiplets. The solutions are regular,
horizonless and have the same asymptotic charges as non-extremal charged black
holes. An essential ingredient in our construction is a four-dimensional
Euclidean base which is a solution to Einstein-Maxwell equations. We construct
stationary solutions based on the Euclidean dyonic Reissner-Nordstrom black
hole as well as a six-parameter family with a dyonic Kerr-Newman-NUT base.
These solutions can be viewed as compactifications of eleven-dimensional
supergravity on a six-torus and we discuss their brane interpretation.Comment: 29 pages, 3 figure
Immunochemical studies on a laminaribiosyl-azoprotein conjugate
Laminaribiose () was coupled to bovine serum albumin (BSA) by an azophenyl linkage to provide the synthetic antigen BSA-p-phenylazo-[beta]-laminaribioside. The behavior of antisera prepared in rabbits immunized with the [beta]-laminaribiosyl conjugate was examined by immunodiffusion, quantitative precipitation and hapten inhibition. Anticonjugate absorbed with carrier protein showed the greatest reactivity with the homologous [beta]-laminaribiosyl-BSA antigen, but also showed some cross precipitation with [beta]-cellobiosyl, [beta]-sophorosyl and [beta]-gentiobiosyl-BSA conjugates. Glucobioses linked through the [beta]-(1 --> 2), [beta]-(1 --> 3), [beta]-(1 --> 4) and [beta]-(1 --> 6) positions, as well as laminaridextrins and tri and tetrasaccharides of [beta]-linked glucose possessing a laminaribiose moiety either at a nonreducing end location or at a subterminal location, were assayed for their ability to inhibit antilaminaribioside precipitation. Hapten inhibition data showed anticonjugate a possess a high degree of specificity directed against the terminal nonreducing [beta]-laminaribiosyl end group.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/32752/1/0000121.pd
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