Thermal instability in ionized plasma

We study magnetothermal instability in the ionized plasmas including the effects of Ohmic, ambipolar and Hall diffusion. Magnetic field in the single fluid approximation does not allow transverse thermal condensations, however, non-ideal effects highly diminish the stabilizing role of the magnetic field in thermally unstable plasmas. Therefore, enhanced growth rate of thermal condensation modes in the presence of the diffusion mechanisms speed up the rate of structure formation.Comment: Accepted for publication in Astrophysics & Space Scienc

A Note on the Finite Convergence of Alternating Projections

We establish sufficient conditions for finite convergence of the alternating projections method for two non-intersecting and potentially nonconvex sets. Our results are based on a generalization of the concept of intrinsic transversality, which until now has been restricted to sets with nonempty intersection. In the special case of a polyhedron and closed half space, our sufficient conditions define the minimum distance between the two sets that is required for alternating projections to converge in a single iteration.Comment: 9 pages, 7 figure

An oscillating hydromagnetic non-Newtonian flow in a rotating system

AbstractAn exact solution of an oscillatory boundary layer flow bounded by two horizontal flat plates, one of which is oscillating in its own plane and the other at rest, is developed. The fluid and the plates are in a state of solid body rotation with constant angular velocity about the z-axis normal to the plates. The fluid is assumed to be second grade, incompressible, and electrically conducting. A uniform transverse magnetic field is applied. During the mathematical analysis, it is found that the steady part of the solution is identical to that of viscous fluid. The structure of the boundary layers is also discussed. Several known results of interest are found to follow as particular cases of the solution of the problem considered

The effect of different treatments on improving seed germination characteristics in medicinal species of Descurainia sophia and Plantago ovata

Creating optimal conditions for germination of medicinal plants seed is essential for their cultivation. Therefore, to evaluate the effect of different treatments on seed germination of two medicinal species, Descurainia sophia and Plantago ovata collected in 2009 from Tehran Province, an experiment with a factorial randomized complete block design in 6 treatments with 4 replications was conducted. Treatments included KNO3 with concentrations of 0.1, 0.2 and 0.3%, acetylsalicylic acid with levels of 50 and 100 mg/l, prechilling (4°C for 10 days), thiourea with levels of 0.1 and 0.2%, boiling water for 5 and 10 min. To compare, distilled water was used as control. Results showed that the effect of different treatments on germination percentage of two medicinal species was significantly different (p < 0.05). It was shown that prechilling was the most effective treatment on seed germination of both species.Key words: Descurainia sophia, Plantago ovata, germination, acetylsalicylic acid, prechilling, thiourea and KNO3

Formation of Small-Scale Condensations in the Molecular Clouds via Thermal Instability

A systematic study of the linear thermal instability of a self-gravitating magnetic molecular cloud is carried out for the case when the unperturbed background is subject to local expansion or contraction. We consider the ambipolar diffusion, or ion-neutral friction on the perturbed states. In this way, we obtain a non-dimensional characteristic equation that reduces to the prior characteristic equation in the non-gravitating stationary background. By parametric manipulation of this characteristic equation, we conclude that there are, not only oblate condensation forming solutions, but also prolate solutions according to local expansion or contraction of the background. We obtain the conditions for existence of the Field lengths that thermal instability in the molecular clouds can occur. If these conditions establish, small-scale condensations in the form of spherical, oblate, or prolate may be produced via thermal instability.Comment: 16 page, accepted by Ap&S

Social franchising and vouchers to promote long-term methods of family planning in rural Pakistan: A qualitative stocktaking with stakeholders

Background: The overall use of modern contraception in Pakistan is quite low, especially in rural areas. Several studies have demonstrated the effectiveness of social franchising (SF) approaches in increasing access to modern contraception and improving the quality of healthcare in resource-poor areas in Asia and Africa. Drawing on best practices in SF, the Marie Stopes Society (MSS) implemented an SF model in certain rural areas of Pakistan to increase access to affordable and quality family planning (FP) services. The model was branded as Suraj (sun) and complemented with an innovative voucher scheme for intrauterine contraceptive devices (IUCDs). This paper describes the perspectives of Suraj clients, field workers mobilization (FWMs), and providers on various components of the Suraj model.Methodology: A qualitative exploratory study was conducted in six randomly selected intervention districts in the Sindh and Punjab provinces. Data were collected using focus group discussions (FGDs) with clients and in-depth interviews (IDIs) with providers and FWMs. Data were manually analyzed using constant comparison and the thematic analysis approach.Findings: Clients showed positive attitudes towards modern contraceptive methods and identified Suraj FWMs and signboards as sources of information. Almost all clients reported IUCDs as effective methods as they have manageable side effects and require fewer visits to clinics. They spoke highly of voucher schemes as these enabled them to avail free IUCD services. Clients also appreciated many components of Suraj clinics, including cleanliness, privacy, confidentiality, the sterilization of instruments, and courteous Suraj providers and FWMs. Most Suraj providers said that IUCD insertion and infection-prevention training enhanced their ability to provide IUCD services and increased their standing in local communities. They reported that the role of FWMs was crucial in mobilizing the community and increasing their FP clientele. The FWMs said that attitudes towards FP were changing because of economic pressure at the household level, increases in literacy, and community mobilization efforts.Conclusion: The Suraj intervention influenced attitudes towards FP and modern contraception, positively. Women using IUCDs showed greater satisfaction with the method. The findings emphasize that SF approaches like Suraj, when complemented with vouchers and community mobilization efforts, can improve the utilization of long-term contraceptive methods among rural and underserved women. The study also identified the need for integrating FP, antenatal care, and safe delivery services

The effect of gender norms on the association between violence and hope among girls in the Democratic Republic of the Congo

Background.Girls at early stages of adolescence are vulnerable to violence victimization in humanitarian contexts, but few studies examine factors that affect girls’ hope in these settings. We assessed attitudes toward traditional gender norms as an effect modifier of the relationship between violence exposure and future orientation in displaced girls.Methods.Secondary analysis, using multivariable regression of cross-sectional data from girls ages 10–14 in South Kivu, Democratic Republic of the Congo. Key variables of interest were attitudes toward intimate partner violence (IPV), Children's Hope Scale (CHS) score, and exposure to physical, emotional, and sexual violence within the last 12 months. Additional covariates included age, educational status, and territory.Results.The interaction of exposure to violence and attitudes toward IPV magnified the association between violence exposure and lower CHS score for physical violence (β = −0.09, p = 0.040) and unwanted sexual touching (β = −0.20, p = 0.003) among girls age 10–14, when adjusting for other covariates. The interaction of exposure to violence and attitudes toward IPV magnified the association between violence exposure and lower CHS score for forced sex (β = −0.22, p = 0.016) among girls age 13–14, when adjusting for covariates. Findings for emotional violence, any form of sexual violence, and coerced sex trended toward lower CHS scores for girls who reported higher acceptance of IPV, but did not reach significance.Conclusions.Findings support the utility of gender norms-transformative programming in increasing resilience of girls who have experienced sexual violence in humanitarian contexts

A probabilistic atlas of finger dominance in the primary somatosensory cortex

With the advent of ultra-high field (7T), high spatial resolution functional MRI (fMRI) has allowed the differentiation of the cortical representations of each of the digits at an individual-subject level in human primary somatosensory cortex (S1). Here we generate a probabilistic atlas of the contralateral SI representations of the digits of both the left and right hand in a group of 22 right-handed individuals. The atlas is generated in both volume and surface standardised spaces from somatotopic maps obtained by delivering vibrotactile stimulation to each distal phalangeal digit using a travelling wave paradigm. Metrics quantify the likelihood of a given position being assigned to a digit (full probability map) and the most probable digit for a given spatial location (maximum probability map). The atlas is validated using a leave-one-out cross validation procedure. Anatomical variance across the somatotopic map is also assessed to investigate whether the functional variability across subjects is coupled to structural differences. This probabilistic atlas quantifies the variability in digit representations in healthy subjects, finding some quantifiable separability between digits 2, 3 and 4, a complex overlapping relationship between digits 1 and 2, and little agreement of digit 5 across subjects. The atlas and constituent subject maps are available online for use as a reference in future neuroimaging studies

How gender- and violence-related norms affect self-esteem among adolescent refugee girls living in Ethiopia.

BACKGROUND: Evidence suggests adolescent self-esteem is influenced by beliefs of how individuals in their reference group perceive them. However, few studies examine how gender- and violence-related social norms affect self-esteem among refugee populations. This paper explores relationships between gender inequitable and victim-blaming social norms, personal attitudes, and self-esteem among adolescent girls participating in a life skills program in three Ethiopian refugee camps. METHODS: Ordinary least squares multivariable regression analysis was used to assess the associations between attitudes and social norms, and self-esteem. Key independent variables of interest included a scale measuring personal attitudes toward gender inequitable norms, a measure of perceived injunctive norms capturing how a girl believed her family and community would react if she was raped, and a peer-group measure of collective descriptive norms surrounding gender inequity. The key outcome variable, self-esteem, was measured using the Rosenberg self-esteem scale. RESULTS: Girl's personal attitudes toward gender inequitable norms were not significantly predictive of self-esteem at endline, when adjusting for other covariates. Collective peer norms surrounding the same gender inequitable statements were significantly predictive of self-esteem at endline (ß = -0.130; p  =  0.024). Additionally, perceived injunctive norms surrounding family and community-based sanctions for victims of forced sex were associated with a decline in self-esteem at endline (ß = -0.103; p  =  0.014). Significant findings for collective descriptive norms and injunctive norms remained when controlling for all three constructs simultaneously. CONCLUSIONS: Findings suggest shifting collective norms around gender inequity, particularly at the community and peer levels, may sustainably support the safety and well-being of adolescent girls in refugee settings