The outburst radial velocity curve of X-Ray Nova Scorpii 1994 (=GRO J1655--40)

We present a reanalysis of the outburst radial velocity data for X-Ray Nova Scorpii 1994. Using a model based on X-ray heating of the secondary star we suggest a more realistic treatment of the radial velocity data. Solutions are obtained in the (K_2,q) plane which, when combined with the published value for the binary mass ratio and inclination, constrain the mass of the black hole to within the region 4.1<M_1<6.6 Msun (90 per cent confidence), which is significantly lower than the value obtained by Orosz & Bailyn (1997). This reduced lower bound for the black hole mass together with the high space velocity of the system is consistent with the idea that it was formed by the post-supernova collapse of a neutron star.Comment: Accepted for MNRAS, 4 pages Latex, 4 figure

Keeper-animal interactions: differences between the behaviour of zoo animals affect stockmanship

Stockmanship is a term used to describe the management of animals with a good stockperson someone who does this in a in a safe, effective, and low-stress manner for both the stock-keeper and animals involved. Although impacts of unfamiliar zoo visitors on animal behaviour have been extensively studied, the impact of stockmanship i.e familiar zoo keepers is a new area of research; which could reveal significant ramifications for zoo animal behaviour and welfare. It is likely that different relationships are formed dependant on the unique keeper-animal dyad (human-animal interaction, HAI). The aims of this study were to (1) investigate if unique keeper-animal dyads were formed in zoos, (2) determine whether keepers differed in their interactions towards animals regarding their attitude, animal knowl- edge and experience and (3) explore what factors affect keeper-animal dyads and ultimately influence animal behaviour and welfare. Eight black rhinoceros (Diceros bicornis), eleven Chapman’s zebra (Equus burchellii), and twelve Sulawesi crested black macaques (Macaca nigra) were studied in 6 zoos across the UK and USA. Subtle cues and commands directed by keepers towards animals were identified. The animals latency to respond and the respective behavioural response (cue-response) was recorded per keeper-animal dyad (n=93). A questionnaire was constructed following a five-point Likert Scale design to record keeper demographic information and assess the job satisfaction of keepers, their attitude towards the animals and their perceived relationship with them. There was a significant difference in the animals’ latency to appropriately respond after cues and commands from different keepers, indicating unique keeper-animal dyads were formed. Stockmanship style was also different between keepers; two main components contributed equally towards this: “attitude towards the animals” and “knowledge and experience of the animals”. In this novel study, data demonstrated unique dyads were formed between keepers and zoo animals, which influenced animal behaviour

Comparing the age-friendliness of different neighbourhoods using district surveys: an example from Hong Kong

Background To address the age-friendliness of living environment in cities, the World Health Organization (WHO) launched the “Age-friendly cities” (AFC) initiative in 2005. To date, however, no universal standard tool for assessing age-friendliness of a community has been agreed. Methodology Two quantitative studies on AFC conducted in two Hong Kong districts—Sha Tin and Tuen Mun—were compared. A total of 801 residents aged ≥50 years were interviewed using structured questionnaires based on the WHO’s AFC criteria. District-wide differences in age-friendliness were compared on the basis of eight domain scores. Multiple linear regression was used to examine associations with demographic and socio-economic characteristics. The provision of services and amenities was also compared to help explain the difference in domain scores. Results Variations in mean domain scores were observed in both districts. Sha Tin showed significantly lower scores in outdoor spaces and buildings, transportation, social participation, respect and social inclusion, civic participation and employment, communication and information, as compared with Tuen Mun. Although a significantly higher score on the housing domain was observed in Sha Tin, differences in community and health services domains were insignificant. Socio-demographic factors, such as age group, gender, area of residence, type of housing, experience of elderly care, employment status, self-rated health and income, were associated with domain scores. However, variations in services and amenities provision appeared not to be strongly associated with district-wide difference in domain scores. Conclusions District differences in public opinions towards age-friendly characteristics were observed in this study. Except for two of the eight domains, Sha Tin had significantly lower scores than Tuen Mun. Some socio-demographic indicators seemed predictive to the differences. Paradoxically, Sha Tin had better services and infrastructure and higher socio-economic status, but lower age-friendliness. This warrants detailed research on psychosocial factors that may influence residents’ perceptions of local environments.published_or_final_versio

Determination of limits on disc masses around six pulsars at 15 and 90 microns

We have searched for evidence of emission at 15 microns with ISOCAM and at 90 microns with ISOPHOT from dust orbiting six nearby pulsars, both in binaries and in isolation, located at distances between about 100 to 1000 pc. No emission was detected at any of the pulsar positions, and for the nearest pulsar J0108-1431 the 3 sigma upper limits on the flux density is about 66 mJy at 15 microns and 22.5 mJy at 90 microns. Upper limits on the masses of circumpulsar dust are inferred at a given temperature using a simple modelling of the radiated flux; they are compared to upper limits of orbiting mass obtained with the dust heating model of Foster & Fisher (1996). These results suggest that it is unlikely that any of them have sufficiently massive, circumpulsar discs out of which planets may form in the future.Comment: 7 pages, 2 figures, revised version, accepted for publication in A&

Urogenital schistosomiasis in Cabo Delgado, northern Mozambique: baseline findings from the SCORE study.

BACKGROUND: The results presented here are part of a five-year cluster-randomised intervention trial that was implemented to understand how best to gain and sustain control of schistosomiasis through different preventive chemotherapy strategies. This paper presents baseline data that were collected in ten districts of Cabo Delgado province, northern Mozambique, before treatment. METHODS: A cross-sectional study of 19,039 individuals was sampled from 144 villages from May to September 2011. In each village prevalence and intensity of S. haematobium were investigated in 100 children first-year students (aged 5-8 years), 100 school children aged 9-12 years (from classes 2 to 7) and 50 adults (20-55 years). Prevalence and intensity of S. haematobium infection were evaluated microscopically by two filtrations, each of 10 ml, from a single urine specimen. Given that individual and community perceptions of schistosomiasis influence control efforts, community knowledge and environmental risk factors were collected using a face-to-face interview. Data were entered onto mobile phones using EpiCollect. Data summary was made using descriptive statistics. Chi-square and logistic regression were used to determine the association between dependent and independent variables. RESULTS: The overall prevalence of urogenital schistosomiasis was 60.4% with an arithmetic mean intensity of infection of 55.8 eggs/10 ml of urine. Heavy infections were detected in 17.7%, of which 235 individuals (6.97%) had an egg count of 1000 eggs/10 ml or more. There was a significantly higher likelihood of males being infected than females across all ages (62% vs 58%; P < 0.0005). Adolescents aged 9-12 years had a higher prevalence (66.6%) and mean infection intensity (71.9 eggs/10 ml) than first-year students (63.1%; 58.2 eggs/10 ml). This is the first study in Mozambique looking at infection rates among adults. Although children had higher levels of infection, it was found here that adults had a high average prevalence and intensity of infection (44.5%; 23.9 eggs/10 ml). Awareness of schistosomiasis was relatively high (68.6%); however, correct knowledge of how schistosomiasis is acquired was low (23.2%) among those who had heard of the disease. Schistosomiasis risk behaviour such as washing (91.3%) and bathing (86.7%) in open water sources likely to be infested with host snails was high. CONCLUSIONS: Urogenital schistosomiasis is widespread in Cabo Delgado. In addition, poor community knowledge about the causes of schistosomiasis and how to prevent it increases the significant public health challenge for the national control program. This was the first study in Mozambique that examined infection levels among adults, where results showed that S. haematobium infection was also extremely high. Given that this controlled trial aims to understand the impact of different combinations of schistosomiasis control through treatment of communities, schools, and treatment holidays over a five-year period, these findings highlight the importance of examining the impact of different treatment approaches also in adults. TRIAL REGISTRATION: The trials have been registered with the International Standard Randomised Controlled Trial registry under ISRCT 14117624 Mozambique (14 December 2015)

Community Development Banking: A Proposal to Establish a Nationwide System of Community Development Banks

Public Policy Brief No. 3, Levy Economics Institute of Bard College

Analysis of complex viscoelastic flows using a finite element method

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2006.Includes bibliographical references (v. 2, leaves 259-268).The field of computational fluid mechanics of viscoelastic flows has been well explored in the three decades since its inception. Still, even with the vast amount of work detailed in the literature, much remains to be done towards the improvement of models of viscoelastic fluids and the improvement of the numerical methods used to solve the set of governing equations. The work contained in this document is concentrated in the latter of these areas. The main goal of this body of work is to develop a robust, efficient simulation package to model three-dimensional viscoelastic flows. In order to accomplish this goal, improvements to the numerical methods and equation formulation were necessary to help reduce the overall size of the equation set used to describe viscoelastic flows in three-dimensional geometries. In order to test their viability for use in reducing the overall size of the problem, concepts involving changing the formulation of the equations and the numerical methods used to find the solution to the equations were first implemented and analyzed in a previously developed two-dimensional finite element simulation package. Implementation and analysis is discussed of a formulation change involving decoupling the calculation of the velocity gradient interpolant equation and the momentum and mass continuity equations in the DEVSS-G formulation.(cont.) Two different decoupled methods for computing the velocity gradient, one using a global least squares approximation and the other a local patch algorithm, are explored. While both methods reduce to the true velocity gradient with mesh refinement, the patch algorithm is shown to require significantly more mesh refinement than the global least squares approximation to order to attain equivalent refinement of the solution. Comparison of the two methods taking into account the additional refinement requirements of the local patch algorithm makes clear the superiority of the decoupled global least squares approximation for calculation of the velocity gradient interpolant. The versatility and robustness of the decoupled form of the DEVSS-G equations are demonstrated through the addition and modification of the evolution equations describing the stress of the polymer as well as new physical quantities of the flow. A time-dependent, free-surface finite element method is developed in which an evolution equation derived from the kinematic boundary condition is used to describe the height of the free surface as a function of time.(cont.) This new evolution equation is incorporated into the decoupled formulation by simply adding an additional step to the time integration to evaluate the change in the height of the surface during the current timestep and then updating the element locations in the deformable region of the mesh. Application of the new equation in this manner requires no knowledge of the direct dependence of the system on changes in the new quantity, allowing for quick and easy implementation. Incorporation of more advanced constitutive equations is used as further example of the utility of the decoupled form of the DEVSS-G equations. For most continuum based constitutive equations, the dependence of the equations on the flow variables can be expressed explicitly, allowing for the coupled set of equations to be solved with Newton's method. However, the dependence of the stress on the flow cannot be explicitly written for more advanced constitutive equations such as those derived from kinetic theory or those employing Brownian dynamics, greatly hindering the performance of Newton's method in locating the solution to the system. As an illustrative example, incorporation into the decoupled equation formulation of the closed form of the Adaptive-Length-Scale model (ALS-C) is presented.(cont.) Simulations are presented capturing for the first time the pressure drop enhancement with increasing viscoelasticity of the model of the flow of a Boger fluid in the 4:1:4 axisymmetric contraction-expansion geometry observed experimentally (Rothstein et al., 2001). Simulations of the flow of a 4-mode FENE-P model fluid within the geometry are also presented. Though its dependence on the flow field can be expressed analytically, the cost of computation using multimode models is typically prohibitive when using fully coupled equation sets as the overall problem size grows considerably with the addition of each new mode. Incorporation of the 4-mode model within the decoupled equation formulation adds relatively little computational cost to the overall calculation. Employing the formulation and numerical methods developed herein, a new three-dimensional finite element package is described for simulating confined viscoelastic flows. To make the package more robust, a number of different boundary conditions are included for modeling different geometries used in polymer processing. To help reduce the burden associated with mesh refinement in three-dimensional meshes, a commercial meshing package utilizing o-grid refinement for localization of refinement is employed.(cont.) Furthermore, to allow for computation of the large equation sets typically associated with three-dimensional geometries, a parallel implementation of the three-dimensional simulation package is developed based on the two-dimensional parallel method developed by Caola et al. ((Caola et al., 2001), (Caola et al., 2002)). Simulation results demonstrating the accuracy and performance of the method are presented. As a test of the robustness of the three-dimensional method, simulations of the flow of Newtonian and Oldroyd-B fluids through a periodic, linear array of cylinders are presented. Comparisons with previous calculations for the Oldroyd-B flow in an infinitely wide domain with no variations in the direction of the width show the same trend in the drag force on the cylinder with increasing viscoelasticity as well as in the size and shape of the vortices formed in the gap between the cylinders. The study of this flow includes effects of modeling the cross section of the flow as an infinite domain with no variation in the direction of the width, an infinite domain of periodic computational width, an infinite domain of periodic computational width and a symmetric flow above and below the cylinders, and a bounded domain with solid walls located 4 cylinder radii apart.by Scott David Phillips.Ph.D

Assessing the benefits of five years of different approaches to treatment of urogenital schistosomiasis: A SCORE project in Northern Mozambique.

BACKGROUND: In Mozambique, schistosomiasis is highly endemic across the whole country. The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) coordinates a five-year study that has been implemented in various African countries, including Mozambique. The overall goal of SCORE was to better understand how to best apply preventive chemotherapy with praziquantel (PZQ) for schistosomiasis control by evaluating the impact of alternative treatment approaches. METHODS: This was a cluster-randomised trial that compared the impact of different treatment strategies in study areas with prevalence among school children of ≥21% S. haematobium infection by urine dipstick. Each village was randomly allocated to one of six possible combinations of community-wide treatment (CWT), school-based treatment (SBT), and/or drug holidays over a period of four years, followed by final data collection in the fifth year. The most intense intervention arm involved four years of CWT, while the least intensive arm involved two years of SBT followed by two consecutive years of PZQ holiday. Each study arm included 25 villages randomly assigned to one of the six treatment arms. The primary outcome of interest was change in prevalence and intensity of S. haematobium among 100 children aged 9-to-12-years that were sampled each year in every village. In addition to children aged 9-to-12 years, 100 children aged 5-8 years in their first-year of school and 50 adults (aged 20-55 years) were tested in the first and final fifth year of the study. Prevalence and intensity of S. haematobium infection was evaluated by two filtrations, each of 10mL, from a single urine specimen. PRINCIPAL FINDINGS: In total, data was collected from 81,167 individuals across 149 villages in ten districts of Cabo Delgado province, Northern Mozambique. Overall PZQ treatment resulted in a significant reduction in the prevalence of S. haematobium infection from Year 1 to Year 5, where the average prevalence went from 60.5% to 38.8%, across all age groups and treatment arms. The proportion of those heavily infected also reduced from 17.6% to 11.9% over five years. There was a significantly higher likelihood of males being infected than females at baseline, but no significant difference between the sexes in their response to treatment. The only significant response based on a study arm was seen in both the 9-to-12-year-old and first-year cross sections, where two consecutive treatment holidays resulted in a significantly higher final prevalence of S. haematobium than no treatment holidays. When the arms were grouped together, four rounds of treatment (regardless of whether it was CWT or SBT), however, did result in a significantly greater reduction in S. haematobium prevalence than two rounds of treatment (i.e. with two intermittent or consecutive holiday years) over a five-year period. CONCLUSIONS: Although PC was successful in reducing the burden of active infection, even among those heavily infected, annual CWT did not have a significantly greater impact on disease prevalence or intensity than less intense treatment arms. This may be due to extremely high starting prevalence and intensity in the study area, with frequent exposure to reinfection, or related to challenges in achieving high treatment coverage More frequent treatment had a greater impact on prevalence and intensity of infection when arms were grouped by number of treatments, however, cost efficiency was greater in arms only receiving two treatments. Finally, a significant reduction in prevalence of S. haematobium was seen in adults even in the SBT arms implying the rate of transmission in the community had been decreased, even where only school children have been treated, which has significant logistical and cost-saving implications for a national control programme in justifying CWT

Unusual thermoelectric behavior of packed crystalline granular metals

Loosely packed granular materials are intensively studied nowadays. Electrical and thermal transport properties should reflect the granular structure as well as intrinsic properties. We have compacted crystalline $CaAl$ based metallic grains and studied the electrical resistivity and the thermoelectric power as a function of temperature ($T$) from 15 to 300K. Both properties show three regimes as a function of temperature. It should be pointed out : (i) The electrical resistivity continuously decreases between 15 and 235 K (ii) with various dependences, e.g. $\simeq$ $T^{-3/4}$ at low $T$, while (iii) the thermoelectric power (TEP) is positive, (iv) shows a bump near 60K, and (v) presents a rather unusual square root of temperature dependence at low temperature. It is argued that these three regimes indicate a competition between geometric and thermal processes, - for which a theory seems to be missing in the case of TEP. The microchemical analysis results are also reported indicating a complex microstructure inherent to the phase diagram peritectic intricacies of this binary alloy.Comment: to be published in J. Appl. Phys.22 pages, 8 figure

Strong-correlation effects in Born effective charges

Large values of Born effective charges are generally considered as reliable indicators of the genuine tendency of an insulator towards ferroelectric instability. However, these quantities can be very much influenced by strong electron correlation and metallic behavior, which are not exclusive properties of ferroelectric materials. In this paper we compare the Born effective charges of some prototypical ferroelectrics with those of magnetic, non-ferroelectric compounds using a novel, self-interaction free methodology that improves on the local-density approximation description of the electronic properties. We show that the inclusion of strong-correlation effects systermatically reduces the size of the Born effective charges and the electron localization lengths. Furthermore we give an interpretation of the Born effective charges in terms of band energy structure and orbital occupations which can be used as a guideline to rationalize their values in the general case.Comment: 10 pages, 4 postscript figure