Constraints on Enhanced Dark Matter Annihilation from IceCube Results

Excesses on positron and electron fluxes measured by ATIC, and the PAMELA and Fermi--LAT telescopes can be explained by dark matter annihilation in our Galaxy. However, this requires large boosts on the dark matter annihilation rate. There are many possible enhancement mechanisms, such as the Sommerfeld effect or the existence of dark matter clumps in our halo. If enhancements on the dark matter annihilation cross section are taking place, the dark matter annihilation in the core of the Earth should also be enhanced. Here we use recent results from the IceCube 40-string configuration to probe generic enhancement scenarios. We present results as a function of the dark matter-proton interaction cross section, $\sigma_{\chi p}$ weighted by the branching fraction into neutrinos, $f_{\nu\bar{\nu}}$, as a function of a generic boost factor, $B_F$, which parametrizes the expected enhancement of the annihilation rate. We find that dark matter models which require annihilation enhancements of $\mathcal{O}(100)$ or more and that annihilate significantly into neutrinos are excluded as the explanation for these excesses. We also determine the boost range that can be probed by the full IceCube telescope.Comment: 6 pages, 3 figures; version accepted for publicatio

On the possible existence of short-period g-mode instabilities powered by nuclear-burning shells in post-asymptotic giant branch H-deficient (PG1159-TYPE) stars

We present a pulsational stability analysis of hot post-asymptotic giant branch (AGB) H-deficient pre-white dwarf stars with active He-burning shells. The stellar models employed are state-of-the-art equilibrium structures representative of PG1159 stars derived from the complete evolution of the progenitor stars, through the thermally pulsing AGB phase and born-again episode. On the basis of fully nonadiabatic pulsation computations, we confirmed theoretical evidence for the existence of a separate PG1159 instability strip in the log Teff-log g diagram characterized by short-period g-modes excited by the ε-mechanism. This instability strip partially overlaps the already known GW Vir instability strip of intermediate/long-period g-modes destabilized by the classical κ-mechanism acting on the partial ionization of C and/or O in the envelope of PG1159 stars. We found that PG1159 stars characterized by thick He-rich envelopes and located inside this overlapping region could exhibit both short and intermediate/long periods simultaneously. As a natural application of our results, we study the particular case of VV 47, a pulsating planetary nebula nucleus (PG1159 type) that is particularly interesting because it has been reported to exhibit a rich and complex pulsation spectrum including a series of unusually short pulsation periods. We found that the long periods exhibited by VV 47 can be readily explained by the classical κ-mechanism, while the observed short-period branch below ≈300 s could correspond to modes triggered by the He-burning shell through the ε-mechanism, although more observational work is needed to confirm the reality of these short-period modes. Were the existence of short-period g-modes in this star convincingly confirmed by future observations, VV 47 could be the first known pulsating star in which both the κ-mechanism and the ε-mechanism of mode driving are simultaneously operating.Facultad de Ciencias Astronómicas y Geofísica

Simultaneous catalytic oxidation of carbon monoxide, hydrocarbons and soot with Ce–Zr–Nd mixed oxides in simulated diesel exhaust conditions

Ce0.73−xZr0.27NdxO2 mixed oxides (x ≤ 0.3) were prepared, characterized by XRD, Raman spectroscopy, N2 adsorption isotherms and H2-TPR, and tested for simultaneous CO, propylene, benzene and soot oxidation in a gas mixture containing O2, NOx, H2O, CO2, CO, propylene (model aliphatic hydrocarbon) and benzene (model aromatic hydrocarbon) that simulates a diesel exhaust. Ce–Zr mixed oxide doping with a low atomic fraction of neodymium (0.01 ≤ x ≤ 0.09) promotes the creation of oxygen vacancies, has a minor effect in the BET specific surface areas of the oxides, increases the surface ceria reducibility and has a positive effect in the catalytic activity. On the contrary, higher neodymium atomic fractions (x = 0.2 and 0.3) promote sintering, with a drastic decrease of the BET specific surface area, surface reducibility and catalytic activity. The Ce0.73−xZr0.27NdxO2 catalysts with x ≤ 0.09 are able to accelerate simultaneously soot, propylene and benzene combustion, and as a general trend, the catalytic behavior of Ce0.73Zr0.27O2 is improved by low atomic fraction neodymium doping (0.01 ≤ x ≤ 0.09). These Ce0.73−xZr0.27NdxO2 mixed oxides with 0.01 ≤ x ≤ 0.09 are also able to accelerate CO oxidation in a certain extent, but there is a net production of CO during soot combustion because the oxidation capacity of these oxides is not high enough to oxidize all CO released as soot combustion product.The authors thank the financial support of CNPq – National Counsel of Technological and Scientific Development (Brazil), of the Spanish Ministry of Economy and Competitiveness (ProjectCTQ2012-30703) and of the UE (FEDER funding)

The begomovirus Tomato leaf curl New Delhi virus is not seed-transmitted in melon

Transmission of plant viruses through seed can be one of the major factors contributing to long- distance dispersal through global trade of seeds and can have important ecological consequences for virus dissemination. Begomoviruses (genus Begomovirus, family Geminiviridae), and among them isolates of the species Tomato leaf curl New Delhi virus (ToLCNDV), cause significant yield losses in economically important crops worldwide. These viruses are horizontally transmitted in nature in a circulative and persistent manner by the whitefly Bemisia tabaci but in recent years several reports have raised the possibility of vertical transmission through seeds for some members of this genus. We have investigated the possible transmission by melon (Cucumis melo L.) seeds of a ToLCNDV isolate of the “Spain” strain, in three different melon cultivars (all susceptible to ToLCNDV). The presence of ToLCNDV in floral tissues and the detection of viral DNA in seeds reveals the seed-borne nature of this virus. However, grow-out studies conducted with the progeny of melon plants germinated from seeds collected from ToLCNDV-infected plants and evaluated at early (1 leaf) or at late (20 leaves) growth stages did not support the vertical transmission of ToLCNDV from seeds to the offspring.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

The begomovirus tomato leaf curl New Delhi virus is not seed-transmitted in melon

Transmission of plant viruses through seed can be one of the major factors contributing to longdistance dispersal through global trade of seeds and can have important ecological consequences for virus dissemination. Begomoviruses (genus Begomovirus, family Geminiviridae), and among them isolates of the species Tomato leaf curl New Delhi virus (ToLCNDV), cause significant yield losses in economically important crops worldwide. These viruses are horizontally transmitted in nature in a circulative and persistent manner by the whitefly Bemisia tabaci but in recent years several reports have raised the possibility of vertical transmission through seeds for some members of this genus. We have investigated the possible transmission by melon (Cucumis melo L.) seeds of a ToLCNDV isolate of the “Spain” strain, in three different melon cultivars (all susceptible to ToLCNDV). The presence of ToLCNDV in floral tissues and the detection of viral DNA in seeds reveals the seed-borne nature of this virus. However, grow-out studies conducted with the progeny of melon plants germinated from seeds collected from ToLCNDV-infected plants and evaluated at early (1 leaf) or at late (20 leaves) growth stages did not support the vertical transmission of ToLCNDV from seeds to the offspring.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Development and validation of the coach's task presentation scale: A quantitative self-report instrument

Objective: A major concern for coaches is the transmission of effective information in the moments before sport practice, when they communicate to players what they are supposed to do and how (Rink, 1994). The present study's main objective was to cover a gap in the sport psychology measurement field and to develop and validate a quantitative self-report instrument to measure the effectiveness of coaches' task presentation for athletes. The resulting instrument was the Escala de Presentacion de las Tareas por Parte del Entrenador (EPTE) [Coach's Task Presentation Scale]. Design: The two studies developed to validate the EPTE used a cross-sectional research design. Method: Participants in Study 1 included 830 college athletes aged between 18 and 27, who completed the EPTE. Participants in Study 2 included 677 college athletes aged between 17 and 29, who completed the EPTE and other questionnaires measuring coach's interpersonal style (autonomy support and controlling style) and basic psychological needs satisfaction/thwarting. Study 1 comprised translation, item formulation and examination of the reliability and factorial structure of the EPTE. Study 2 provided evidence of factorial validity and evidence of validity based on relationships with other variables in the context of the Self Determination Theory (Deci & Ryan, 2000). Results: The results of reliability analysis and the different sources of validity provided, demonstrated the instrument's adequacy in terms of psychometric properties. Conclusions: The EPTE is a valid, reliable scale that can be used to measure the effectiveness of task presentation by coaches, according to the perception of athletes

Genomic analysis of bovine herpesvirus type 4 (BoHV-4) from Argentina: High genetic variability and novel phylogenetic groups

Bovine herpesvirus 4 (BoHV-4) is a γ-herpesvirus that has been isolated both from apparently healthy animals and from cattle with a variety of clinical signs, including post-partum endometritis and abortion. BoHV-4 causes either a persistent or a latent infection in cells of the monocyte/macrophage lineage. Two groups of BoVH-4 strains have been defined based on their restriction patterns: the Movar-like strains (European prototype) and the DN 599-like strains (American prototype). The purpose of the present study was to genetically characterize wild type BoHV-4 strains isolated from vaginal discharges of aborted cows in Argentina. The virus was identified by isolation and nested PCR in all vaginal discharge samples from aborted cows, either as a sole agent or in association with other pathogens. Restriction enzyme profiling and phylogenetic analysis demonstrated that there is a high genetic variability among the studied field isolates. The existence of three groups of strains, which were designated as genotypes 1, 2 and 3, is described. Genotypes 1 and 2 possibly correspond to the Movar-like and DN 599-like groups, respectively, whereas Genotype 3 corresponds to a novel group. Two viral strains did not cluster into any of these three groups, indicating that other genotypes could be circulating in Argentina. These results suggest a complex epidemiological background for the Argentinean BoHV-4 strains, probably influenced by independent events of genetic drift. This hypothesis cannot be rejected based on the available data. However, there is no direct evidence supporting this possibility. Thus, it seems speculative to suggest that interspecific jumps are responsible for the observed phylogenetic grouping. On the other hand, our analyses suggest a geographical structure for the observed viral genotypes, since genotypes 1 and 2 included the European (Movar-like) and American (DN599-like) reference strains, respectively. Geographic dispersion is known to be a driver of herpes viruses diversification, and independent evolution in geographical isolated places ensures the emergence of particular mutations in each location due to genetic drift (Compans, 2007; Zong et al., 1999). Therefore, at this point, the genetic drift hypothesis is the one that requires less ad-hoc considerations and thus, to our understanding, is the one that fits to the findings from this study. The involvement of this genetic variability in the detection and pathogenesis of BoHV-4 remains to be investigated.Fil: Verna, Andrea Elizabeth. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Área de Investigación en Producción y Sanidad Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Manrique, Julieta Marina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación Playa Unión. Estación de Fotobiología Playa Unión; ArgentinaFil: Pérez, Sandra Elizabeth. Universidad Nacional del Centro de la Provincia de Buenos Aires; ArgentinaFil: Leunda, M. R.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Área de Investigación en Producción y Sanidad Animal; ArgentinaFil: Pereyra, Susana Beatriz. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Área de Investigación en Producción y Sanidad Animal; ArgentinaFil: Jones, Leandro Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación Playa Unión. Estación de Fotobiología Playa Unión; ArgentinaFil: Odeón, Anselmo Carlos. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Área de Investigación en Producción y Sanidad Animal; Argentin