Constraining Relativistic Bow Shock Properties in Rotation-Powered Millisecond Pulsar Binaries

Multiwavelength followup of unidentified Fermi sources has vastly expanded the number of known galactic-field "black widow" and "redback" millisecond pulsar binaries. Focusing on their rotation-powered state, we interpret the radio to X-ray phenomenology in a consistent framework. We advocate the existence of two distinct modes differing in their intrabinary shock orientation, distinguished by the phase-centering of the double-peaked X-ray orbital modulation originating from mildly-relativistic Doppler boosting. By constructing a geometric model for radio eclipses, we constrain the shock geometry as functions of binary inclination and shock stand-off $R_0$. We develop synthetic X-ray synchrotron orbital light curves and explore the model parameter space allowed by radio eclipse constraints applied on archetypal systems B1957+20 and J1023+0038. For B1957+20, from radio eclipses the stand-off is $R_0 \sim 0.15$ -- $0.3$ fraction of binary separation from the companion center, depending on the orbit inclination. Constructed X-ray light curves for B1957+20 using these values are qualitatively consistent with those observed, and we find occultation of the shock by the companion as a minor influence, demanding significant Doppler factors to yield double peaks. For J1023+0038, radio eclipses imply $R_0 \lesssim 0.4$ while X-ray light curves suggest $0.1\lesssim R_0 \lesssim 0.3$ (from the pulsar). Degeneracies in the model parameter space encourage further development to include transport considerations. Generically, the spatial variation along the shock of the underlying electron power-law index should yield energy-dependence in the shape of light curves motivating future X-ray phase-resolved spectroscopic studies to probe the unknown physics of pulsar winds and relativistic shock acceleration therein.Comment: Accepted to ApJ, 36 pages, 15 figures; comments welcom

Die gesinsdinamika van pastoriegesinne in die drie Afrikaanse kerke

The divorce rate among white South Africans is disturbing. There are indications of a growing divorce rate also among families of ministers of religion. Little scientific research seems to be available on the marital and family life of ministers, especially in the RSA. The aim of the research on which this article is based was to determine whether significant differences occur between the marital and family dynamics of ministers' families and the families of parishioners. Thirty clerical couples and some of their children (N=96) and thirty parish couples and some of their children (N=95) were involved in the research. Six measuring instruments were applied in evaluating the families. The results seem to indicate that the clerical couples experience their marital dynamics significantly better than the other married couples on 12 o f the 19 dimensions which were evaluated. With regard to family functioning the ministers’ families performed significantly better than the parish fa milies on six of the 14 dimensions. There are indications, however, that the clerical couples represented their marital and family functioning in a more positive light than was the case in reality. Therefore no really valid interpretations can be made from the results

Life-design counselling for survivors of family violence in resource-constrained areas

The purpose of this study was to explore and assess the feasibility of counselling based on life-design principles in enhancing the career resilience of children who are exposed to family violence. The research project involved a QUALITATIVE–quantitative mode of inquiry with 6 participants chosen based on certain characteristics. Life-designrelated intervention strategies, together with various (postmodern) qualitative and quantitative techniques, were used to gather data, while data analysis was done using thematic content analysis. Quantitative data were collected from parents as well as the participants before and after the intervention. Certain themes, sub-themes and sub-sub-themes that all contributed to participants’ career resilience were identified. Following the intervention, findings obtained from a qualitative perspective indicated that the outcomes of the life-design-related counselling intervention were substantial. The findings showed that various narrative techniques could be used to enhance the career resilience of children exposed to family violence. Future research could assess the value of life-design counselling in enhancing the career resilience of survivors of family violence in diverse group contexts. A greater focus could be placed on the (unforeseen) external trauma that had an impact onparticipants’ ability to (re-)construct their career-life narratives to enhance their future selves and careers. Keywords: adaptability; career resilience; careers; children; family violence; life-design; narrative; resilience; traum

Financial risk tolerance: An analysis of unexplored factors

Using data from a survey alliance between Kiplinger's Personal Finance Magazine, PBS's Nightly Business Report, and FinaMetrica, this study explores various demographical and attitudinal factors related to financial risk tolerance. Investigating risk tolerance scores of more than 2,000 individuals immediately after the 2008 Global Financial Crisis, we find a positive relationship between risk tolerance and income, investment knowledge and positive stock market expectations. Risk tolerance is found to be lower for females, older individuals, those that currently use a financial advisor and individuals that perceive the stock market to be riskier than two years before

Profile of children diagnosed with cerebral palsy at Universitas Hospital, Bloemfontein, 1991-2001

Cerebral palsy is a term used for a group of non-progressive but often changing motor deficits, which are a result of a lesion of the brain occurring at an early developmental stage. Cerebral palsy may be classified physiologically or topographically. Physiologically, there are five types of cerebral palsy1: spastic, dyskinetic, ataxic, hypotonic, and mixed. Topographically, there are six types1: hemiplegia (one arm and leg on the same side of the body are affected), monoplegia (one limb is affected), diplegia (both legs more affected than arms), quadriplegia (all limbs, body and face symmetrically affected), triplegia (three limbs are affected, usually both legs and one arm), and double hemiplegia (both sides of the body are affected asymmetrically, arms usually more than the legs).For full text, click here:SA Fam Pract 2006;48(3):15-1

Di-μ-iodido-bis­[acet­yl(4-methyl-2,6,7-trioxa-1-phosphabicyclo­[2.2.2]octa­ne)(N-nitroso-N-oxidoaniline-κ2 O,O′)rhodium(III)]

The title compound, [Rh2(C6H5N2O2)2(C2H3O)2I2(C5H9O3P)2], contains a binuclear centrosymmetric RhIII dimer bridged by iodide anions, with respective Rh⋯Rh and I⋯I distances of 4.1437 (5) and 3.9144 (5) Å. The RhIII atom is in a distorted octa­hedral RhCI2O2P coordination with considerably different Rh—I distances to the bridging iodide anions. There are no classical hydrogen-bonding inter­actions observed for this complex

The natural history of peanut sensitization and allergy in a birth cohort

Information on the natural history of peanut-induced allergic sensitization (PAS) and clinical peanut allergy (PA) remains limited. Most previous studies selected children who were given a diagnosis of PA, which does not provide the population perspective and probably ignores those with low levels of sensitization.1,2 There are no population-based studies on the natural history of PAS or PA. To provide a population perspective, we used the Isle of Wight birth cohort (n = 1456) and determined the natural history of PAS and PA, focusing on incidence, persistence, and remission

Compliance in black patients with non-insulindependent diabetes mellitus receiving oral hypoglycaemic therapy

Poor compliance with drug therapy is an important cause of therapeutic failure. Sixty-eight black patients with non-insulin- dependent diabetes mellitus receiving oral hypoglycaemic agents were interviewed and various factors, such as age, sex, degree of control and type of therapy, were recorded by means of a questionnaire. Compliance was determined by qualitatively assessing urine for the presence of the drugs. An alarmingly high incidence of non-compliance of 65% was found, which could still be an under-estimation because of the long half-life of one of the drugs involved - chlorpropamide. Although interesting trends were noted, no statistically significant differences between compliant and non-compliant patients were found. In the light of the high incidence of non-compliance, a larger and more detailed study seems to be warranted to identify problem areas and to plan appropriate interventions

Spatially explicit estimates of forest carbon emissions, mitigation costs and REDD+ opportunities in Indonesia

Carbon emissions from the conversion and degradation of tropical forests contribute to anthropogenic climate change. Implementing programs to reduce emissions from tropical forest loss in Southeast Asia are perceived to be expensive due to high opportunity costs of avoided deforestation. However, these costs are not representative of all REDD+ opportunities as they are typically based on average costs across large land areas and are primarily for reducing deforestation from oil palm or pulp concessions. As mitigation costs and carbon benefits can vary according to site characteristics, spatially-explicit information should be used to assess cost-effectiveness and to guide the allocation of scarce REDD+ resources. We analyzed the cost-effectiveness of the following REDD+ strategies in Indonesia, one of the world's largest sources of carbon emissions from deforestation: halting additional deforestation in protected areas, timber and oil palm concessions, reforesting degraded land and employing reduced-impact logging techniques in logging concessions. We discover that when spatial variation in costs and benefits is considered, low-cost options emerged even for the two most expensive strategies: protecting forests from conversion to oil palm and timber plantations. To achieve a low emissions reduction target of 25%, we suggest funding should target deforestation in protected areas, and oil palm and timber concessions to maximize emissions reductions at the lowest cumulative cost. Low-cost opportunities for reducing emissions from oil palm are where concessions have been granted on deep peat deposits or unproductive land. To achieve a high emissions reduction target of 75%, funding is allocated across all strategies, emphasizing that no single strategy can reduce emissions cost-effectively across all of Indonesia. These findings demonstrate that by using a spatially-targeted approach to identify high priority locations for reducing emissions from deforestation and forest degradation, REDD+ resources can be allocated cost-effectively across Indonesia

H3 histamine receptor-mediated activation of protein kinase calpha inhibits the growth of cholangiocarcinoma in vitro and in vivo

Histamine regulates functions via four receptors (HRH1, HRH2, HRH3, and HRH4). The D-myo-inositol 1,4,5-trisphosphate (IP(3))/Ca(2+)/protein kinase C (PKC)/mitogen-activated protein kinase pathway regulates cholangiocarcinoma growth. We evaluated the role of HRH3 in the regulation of cholangiocarcinoma growth. Expression of HRH3 in intrahepatic and extrahepatic cell lines, normal cholangiocytes, and human tissue arrays was measured. In Mz-ChA-1 cells stimulated with (R)-(alpha)-(-)-methylhistamine dihydrobromide (RAMH), we measured (a) cell growth, (b) IP(3) and cyclic AMP levels, and (c) phosphorylation of PKC and mitogen-activated protein kinase isoforms. Localization of PKC alpha was visualized by immunofluorescence in cell smears and immunoblotting for PKC alpha in cytosol and membrane fractions. Following knockdown of PKC alpha, Mz-ChA-1 cells were stimulated with RAMH before evaluating cell growth and extracellular signal-regulated kinase (ERK)-1/2 phosphorylation. In vivo experiments were done in BALB/c nude mice. Mice were treated with saline or RAMH for 44 days and tumor volume was measured. Tumors were excised and evaluated for proliferation, apoptosis, and expression of PKC alpha, vascular endothelial growth factor (VEGF)-A, VEGF-C, VEGF receptor 2, and VEGF receptor 3. HRH3 expression was found in all cells. RAMH inhibited the growth of cholangiocarcinoma cells. RAMH increased IP(3) levels and PKC alpha phosphorylation and decreased ERK1/2 phosphorylation. RAMH induced a shift in the localization of PKC alpha expression from the cytosolic domain into the membrane region of Mz-ChA-1 cells. Silencing of PKC alpha prevented RAMH inhibition of Mz-ChA-1 cell growth and ablated RAMH effects on ERK1/2 phosphorylation. In vivo, RAMH decreased tumor growth and expression of VEGF and its receptors; PKC alpha expression was increased. RAMH inhibits cholangiocarcinoma growth by PKC alpha-dependent ERK1/2 dephosphorylation. Modulation of PKC alpha by histamine receptors may be important in regulating cholangiocarcinoma growth. (Mol Cancer Res 2009;7(10):1704-13