Extreme scattering events and Galactic dark matter

Extreme Scattering Events (ESEs) are attributed to radio-wave refraction by a cloud of free-electrons crossing the line-of-sight. We present a new model in which these electrons form the photo-ionized 'skin' of an underlying cool, self-gravitating cloud in the Galactic halo. In this way we avoid the severe over-pressure problem which afflicts other models. The UV flux in the Galactic halo naturally generates electron densities of the right order. We demonstrate, for the first time, a good reproduction of the prototypical ESE in the quasar 0954+658. The neutral clouds are a few AU in radius and have masses less than about 10^{-3} solar. The observed rate of ESEs implies that a large fraction of the mass of the Galaxy is in this form.Comment: 5 pp incl 3 figs, LaTeX, uses aas2pp4.sty. Minor revisions. ApJ Letters in pres

The Effects of Private Self-Consciousness and Perspective Taking on Satisfaction in Close Relationships.

131 heterosexual student couples, aged 17–32 yrs, 30 of whom were married or engaged answered questions concerning themselves and their relationships. It was predicted that individual differences in private self-consciousness would be positively related to relationship satisfaction because of the greater self-disclosure resulting from that heightened self-attention. It was further predicted that individual differences in perspective taking would foster relationship satisfaction, independent of any influence of self-disclosure. Both expectations were confirmed. Scores on the private self-consciousness scale were predictive of reported self-disclosure, and self-disclosure was predictive of satisfaction in the relationship. Once the influence of self-disclosure was removed, no effect of self-consciousness on satisfaction remained. In contrast, after disclosure was controlled, perspective-taking scores were significantly related to satisfaction and were in fact unrelated to disclosure at all. Findings indicate that 2 personality characteristics having to do with habitual attention to behavioral tendencies, emotions, and motivations significantly enhance the quality of close heterosexual relationships in different ways

We were treated like machines : professionalism and anti-Blackness in social work agency culture

This exploratory study sought to answer two overarching research questions: (1) To what extent is there color-blind anti-Black bias in the way that professionalism is defined and enforced in social work agency culture? (2) What are exacerbating and ameliorating factors for this anti-Black bias? I developed a mixed-methods online questionnaire and recruited 246 participants via e-mail and Facebook. Participants were mostly White female social workers 18-39 years old, though the sample was disproportionately African American as compared with the general social worker population. When participants were asked if they perceived anti-Black bias in professionalism at their agencies, 42.7% answered yes while 57.3% answered no. A t-test demonstrated a significant difference in agencies’ percentage of African American staff members by reported bias (t(113) = 3.24, p = .002, two-tailed). Participants who answered yes to bias had a lower mean percentage of African American staff in their agencies (M = 2.70, SD = 1.17) than those who answered no (M = 3.49, SD = 1.37). There were no significant relationships found between bias reporting and age, race, or gender. However, a chi-square test found a significant difference in bias reporting by supervisory status (χ2(1, n = 115) = 4.18, p = .041, continuity corrected). A larger percentage of participants who were not in a supervisory role (58.7%) answered yes to anti-Black bias, compared to 41.3% of supervisors. Anti-racist trainings, anti-racist policies and procedures, and increased staff diversity were the three most common recommendations given to reduce anti-Black bias in professionalism. Overall, the findings suggest that anti-Black bias is widespread in social work professional culture, and that concerted reform efforts will be necessary to dismantle it

Cosmic Strings, Zero Modes and SUSY breaking in Nonabelian N=1 Gauge Theories

We investigate the microphysics of cosmic strings in Nonabelian gauge theories with N=1 supersymmetry. We give the vortex solutions in a specific example and demonstrate that fermionic superconductivity arises because of the couplings and interactions dictated by supersymmetry. We then use supersymmetry transformations to obtain the relevant fermionic zero modes and investigate the role of soft supersymmetry breaking on the existence and properties of the superconducting strings.Comment: 12 pages, RevTex, submitted to Phys. Rev.

Llama Failure to Thrive Syndrome

The llama (Lama glama) presents today\u27s veterinarian with all the difficulties and medical uncertainties of treating a new species. Both the rapid increase in their numbers in the United States, and their relatively high monetary values have contributed to their recent significance in veterinary medicine. Complexities encountered by the veterinarian begin with llama anatomy and physiology, both of which are somewhat different \u27from what is seen in common domestic species such as the equine, bovine, or ovine. Thus, it is not surprising that some llama diseases present uniquely and are poorly understood and researched at this time. An important condition which belongs in this category is the failure to thrive syndrome of llamas (FTS)

Using Simulated Farm Case Studies to Teach Financial and Risk Management Concepts

Two simulated farm case studies provide a means for teaching financial and risk management strategies to western Kentucky grain farmers. Aggregate financial data for 227 grain farms define the case studies, which illustrate how cost and debt affect cash flow and working capital over a 5-year period. Responding to the case studies, farmers were able to discuss these financial concepts in a group setting among competitor neighbors without revealing personal business information. The use of composite financial data engaged the farmers and allowed for improved discussion on risk management products and the potential to protect working capital over multiple years. Extension professionals can apply the methods described

Cholinergic suppression: A postsynaptic mechanism of long-term associative learning

Food avoidance learning in the mollusc Pleurobranchaea entails reduction in the responsiveness of key brain interneurons in the feeding neural circuitry, the paracerebral feeding command interneurons (PCNs), to the neurotransmitter acetylcholine (AcCho). Food stimuli applied to the oral veil of an untrained animal depolarize the PCNs and induce the feeding motor program (FMP). Atropine (a muscarinic cholinergic antagonist) reversibly blocks the food-induced depolarization of the PCNs, implicating AcCho as the neurotransmitter mediating food detection. AcCho applied directly to PCN somata depolarizes them, indicating that the PCN soma membrane contains AcCho receptors and induces the FMP in the isolated central nervous system preparation. The AcCho response of the PCNs is mediated by muscariniclike receptors, since comparable depolarization is induced by muscarinic agonists (acetyl-ß -methylcholine, oxotremorine, pilocarpine), but not nicotine, and blocked by muscarinic antagonists (atropine, trifluoperazine). The nicotinic antagonist hexamethonium, however, blocked the AcCho response in four of six cases. When specimens are trained to suppress feeding behavior using a conventional food-avoidance learning paradigm (conditionally paired food and shock), AcCho applied to PCNs in the same concentration as in untrained animals causes little or no depolarization and does not initiate the FMP. Increasing the concentration of AcCho 10-100 times, however, induces weak PCN depolarization in trained specimens, indicating that learning diminishes but does not fully abolish AcCho responsiveness of the PCNs. This study proposes a cellular mechanism of long-term associative learning -- namely, postsynaptic modulation of neurotransmitter responsiveness in central neurons that could apply also to mammalian species

The time-reversal test for stochastic quantum dynamics

The calculation of quantum dynamics is currently a central issue in theoretical physics, with diverse applications ranging from ultra-cold atomic Bose-Einstein condensates (BEC) to condensed matter, biology, and even astrophysics. Here we demonstrate a conceptually simple method of determining the regime of validity of stochastic simulations of unitary quantum dynamics by employing a time-reversal test. We apply this test to a simulation of the evolution of a quantum anharmonic oscillator with up to $6.022\times10^{23}$ (Avogadro's number) of particles. This system is realisable as a Bose-Einstein condensate in an optical lattice, for which the time-reversal procedure could be implemented experimentally.Comment: revtex4, two figures, four page