Neutrino flux predictions for known Galactic microquasars

It has been proposed recently that Galactic microquasars may be prodigious emitters of TeV neutrinos that can be detected by upcoming km^2 neutrino telescopes. In this paper we consider a sample of identified microquasars and microquasar candiates, for which available data enables rough determination of the jet parameters. By employing the parameters inferred from radio observations of various jet ejection events, we determine the neutrino fluxes that should have been produced during these events by photopion production in the jet. Despite the large uncertainties in our analysis, we demonstrate that in several of the sources considered, the neutrino flux at Earth, produced in events similar to those observed, would exceed the detection threshold of a km^2 neutrino detector. The class of microquasars may contain also sources with bulk Lorentz factors larger than those characteristic of the sample considered here, directed along our line of sight. Such sources, which may be very difficult to resolve at radio wavelengths and hence may be difficult to identify as microqusar candidates, may emit neutrinos with fluxes significantly larger than typically obtained in the present analysis. These sources may eventually be identified through their neutrino and gamma-ray emission.Comment: 17 pages. Submitted to Ap

The politics of autocratic survival in Equatorial Guinea: co-optation, restrictive institutional rules, repression, and international projection

Equatorial Guinea is not only one of the world’s most authoritarian regimes but also a striking case of regime and leader survival. This small, oil-rich state and personalist regime defies conventional wisdom because it is both far more resilient and faces far fewer threats from within the regime and from opposition political parties than other resource-rich states. But how does the regime manage to survive? This study argues that four key mechanisms interact to explain Equatorial Guinea’s record of authoritarian survival. Firstly, co-optation (via patronage, party, and cabinet appointments) which President Teodoro Obiang Nguema Mbasogo and the regime party—Partido democrático de guinea ecuatorial—have used to build internal cohesion and fragment opposition. Secondly, the crafting of restrictive institutional rules (party and electoral laws) that, combined with informal rules, aim to protect the regime’s interests and make participation in political opposition more costly. Thirdly, the use of (selective and diffuse) repression to shield the regime and shrink the living space of challengers. Finally, the regime’s international linkages and projection to gain credibility and offset pressure for change. We argue that autocrats’ survival depends on their ability to play a strategic two-level game: domestic and international.info:eu-repo/semantics/acceptedVersio

Measuring monopole and dipole polarizability of acoustic meta-atoms

We present a method to extract monopole and dipole polarizability from experimental measurements of two-dimensional acoustic meta-atoms. In contrast to extraction from numerical results, this enables all second-order effects and uncertainties in material properties to be accounted for. We apply the technique to 3D-printed labyrinthine meta-atoms of a variety of geometries. We show that the polarizability of structures with shorter acoustic path length agrees well with numerical results. However, those with longer path lengths suffer strong additional damping, which we attribute to the strong viscous and thermal losses in narrow channels

Disordered Bose Einstein Condensates with Interaction in One Dimension

We study the effects of random scatterers on the ground state of the one-dimensional Lieb-Liniger model of interacting bosons on the unit interval in the Gross-Pitaevskii regime. We prove that Bose Einstein condensation survives even a strong random potential with a high density of scatterers. The character of the wave function of the condensate, however, depends in an essential way on the interplay between randomness and the strength of the two-body interaction. For low density of scatterers or strong interactions the wave function extends over the whole interval. High density of scatterers and weak interaction, on the other hand, leads to localization of the wave function in a fragmented subset of the interval

Genomic instability in human actinic keratosis and squamous cell carcinoma

OBJECTIVE: To compare the repetitive DNA patterns of human actinic keratoses and squamous cell carcinomas to determine the genetic alterations that are associated with malignant transformation. INTRODUCTION: Cancer cells are prone to genomic instability, which is often due to DNA polymerase slippage during the replication of repetitive DNA and to mutations in the DNA repair genes. The progression of benign actinic keratoses to malignant squamous cell carcinomas has been proposed by several authors. MATERIAL AND METHODS: Eight actinic keratoses and 24 squamous cell carcinomas (SCC), which were pair-matched to adjacent skin tissues and/or leucocytes, were studied. The presence of microsatellite instability (MSI) and the loss of heterozygosity (LOH) in chromosomes 6 and 9 were investigated using nine PCR primer pairs. Random Amplified Polymorphic DNA patterns were also evaluated using eight primers. RESULTS: MSI was detected in two (D6S251, D9S50) of the eight actinic keratosis patients. Among the 8 patients who had squamous cell carcinoma-I and provided informative results, a single patient exhibited two LOH (D6S251, D9S287) and two instances of MSI (D9S180, D9S280). Two LOH and one example of MSI (D6S251) were detected in three out of the 10 patients with squamous cell carcinoma-II. Among the four patients with squamous cell carcinoma-III, one patient displayed three MSIs (D6S251, D6S252, and D9S180) and another patient exhibited an MSI (D9S280). The altered random amplified polymorphic DNA ranged from 70% actinic keratoses, 76% squamous cell carcinoma-I, and 90% squamous cell carcinoma-II, to 100% squamous cell carcinoma-III. DISCUSSION: The increased levels of alterations in the microsatellites, particularly in D6S251, and the random amplified polymorphic DNA fingerprints were statistically significant in squamous cell carcinomas, compared with actinic keratoses. CONCLUSION: The overall alterations that were observed in the repetitive DNA of actinic keratoses and squamous cell carcinomas indicate the presence of a spectrum of malignant progression

Who gets what? The interactive effect of MPs’ sex in committee assignments in Portugal

This article investigates the role of key individual-level factors, namely expertise, seniority and preferences in women’s assignments to legislative committees. It focuses on Portugal and draws on biographical data on MPs in five elections until 2009 and interviews with 20 legislators in 2014. The results show that female and male MPs have a similar probability of being appointed to powerful and economic issue committees, but female MPs are more likely to be appointed to social issue committees regardless of expertise and seniority. Although this outcome might be the product of their own preferences, it is influenced by embedded gender norms.info:eu-repo/semantics/publishedVersio

Preditores socio-demográficos, clínicos e de saúde oral auto-percebida nos idosos

Poster apresentado nas XXIV Jornadas Internacionais de Medicina Dentária do ISCSEM, 4-5 Março 2015, Egas Moniz, Caparica, Portugal