Implications for compressed sensing of a new sampling theorem on the sphere

A sampling theorem on the sphere has been developed recently, requiring half as many samples as alternative equiangular sampling theorems on the sphere. A reduction by a factor of two in the number of samples required to represent a band-limited signal on the sphere exactly has important implications for compressed sensing, both in terms of the dimensionality and sparsity of signals. We illustrate the impact of this property with an inpainting problem on the sphere, where we show the superior reconstruction performance when adopting the new sampling theorem compared to the alternative.Comment: 1 page, 2 figures, Signal Processing with Adaptive Sparse Structured Representations (SPARS) 201

Sparse image reconstruction on the sphere: implications of a new sampling theorem

We study the impact of sampling theorems on the fidelity of sparse image reconstruction on the sphere. We discuss how a reduction in the number of samples required to represent all information content of a band-limited signal acts to improve the fidelity of sparse image reconstruction, through both the dimensionality and sparsity of signals. To demonstrate this result we consider a simple inpainting problem on the sphere and consider images sparse in the magnitude of their gradient. We develop a framework for total variation (TV) inpainting on the sphere, including fast methods to render the inpainting problem computationally feasible at high-resolution. Recently a new sampling theorem on the sphere was developed, reducing the required number of samples by a factor of two for equiangular sampling schemes. Through numerical simulations we verify the enhanced fidelity of sparse image reconstruction due to the more efficient sampling of the sphere provided by the new sampling theorem.Comment: 11 pages, 5 figure

Coping with multiple adversities: Men who sought medico-legal care because of physical violence from a partner or ex-partner.

Objectives: To describe male victims of physical violence by an intimate partner who consulted a medico-legal unit, and information available on their perpetrators; to characterize the violent events and their contexts. Little research exists on male victims of physical intimate partner violence seeking medical care. Method: Based on Heise’s ecological framework, mixed methods were used to analyze quantitative and qualitative data collected during 122 medico-legal consultations attended by 115 men who sustained physical violence by an intimate partner from 2006–2012. Results: Quantitative and quantitative data collected from male victims concurred in showing that many of such victims, as well as their partners, faced at the time of the assault multiple adversities and challenges at individual and relationship levels. Among male victims, 26% had no paid job. Among perpetrators, 34% were third-country nationals subject to restricted residence permits. Health issues, worries about money or work combined with complex and conflictive family situations were often in the background of violent events. In a few cases, however, male victims reported no other problems than their partner’s assault. Conclusions: Our findings point out gender-specific aspects of female-to-male physical partner violence. The most common feature is that violence was experienced as one among several adversities. Even though wounds sustained by male victims were not necessarily severe, their emotional suffering was frequent. When underage children were involved, their situation was particularly noteworthy. Interventions with male victims of intimate partner violence should include protection of minors as a priority and as an incentive for fathers to seek help

Teen Dating Violence in French-speaking Switzerland: Attitudes and Experiences

Research on dating violence has tended to focus on North American college students. This study innovates with data collected in Switzerland from a sample of 132 school pupils and vocational education students aged 14 to 22 using a self-administered questionnaire. The study investigates relationships between attitudes and experiences about dating violence and the effect of gender. Biases against women were common in the sample. Females reported less endorsement of patriarchal attitudes about women’s roles, but both genders reported similar levels of disparagement of women. Participants reported high rates of physical violence perpetration (41.9 percent) and victimization (48.8 percent). Pro-violence attitudes were related to psychological and physical perpetration as well as physical victimization. For female respondents, essentialist beliefs about women’s innate abilities appear more persistent than beliefs about appropriate roles. Male participants endorsed both types of gender stereotypes at high rates. Male-perpetrated violence was perceived less favorably than female-perpetrated violence. Our data suggest that general attitudes toward violence are the most consistent predictor of physical and psychological aggression within dating relationships. More attention needs to be paid to subtypes among attitudes on women and violence, which past research assumed were monolithic. This study shows the need for prevention programs to address pro-violence attitudes

Possible flakes of molecular hydrogen in the early Universe

The thermochemistry of H2 and HD in non-collapsed, non-reionized primordial gas up to the end of the dark age is investigated with recent radiation-matter and chemical reaction rates taking into account the efficient coolant HD, and the possibility of a gas-solid phase transition of H2. In the standard big-bang model we find that these molecules can freeze out and lead to the growth of flakes of solid molecular hydrogen at redshifts z ~ 6-12 in the unperturbed medium and under-dense regions. While this freezing caused by the mere adiabatic cooling of the expanding matter is less likely to occur in collapsed regions due to their higher than radiation background temperature, on the other hand the super-adiabatic expansion in voids strongly favors it. Later reionization (at z ~ 5-6) eventually destroys all these H2 flakes. The possible occurrence of H2 flakes is important for the degree of coupling between matter and radiation, as well as for the existence of a gas-grain chemistry at the end of the dark age.Comment: Accepted for publication to Astronomy and Astrophysic