Prospects for Type Ia Supernova explosion mechanism identification with gamma rays

The explosion mechanism associated with thermonuclear supernovae (SNIa) is still a matter of debate. There is a wide agreement that high amounts of of radioactive nuclei are produced during these events and they are expected to be strong gamma-ray emitters. In the past, several authors have investigated the use of this gamma-ray emission as a diagnostic tool. In this paper we have done a complete study of the gamma-ray spectra associated with all the different scenarios currently proposed. This includes detonation, delayed detonation, deflagration and the off-center detonation. We have performed accurate simulations for this complete set of models in order to determine the most promising spectral features that could be used to discriminate among the different models. Our study is not limited to qualitative arguments. Instead, we have quantified the differences among the spectra and established distance limits for their detection. The calculations have been performed considering the best current response estimations of the SPI and IBIS instruments aboard INTEGRAL in such a way that our results can be used as a guideline to evaluate the capabilities of INTEGRAL in the study of type Ia supernovae. For the purpose of completeness we have also investigated the nuclear excitation and spallation reactions as a possible secondary source of gamma-rays present in some supernova scenarios. We conclude that this mechanism can be neglected due to its small contribution.Comment: 10 pages, 12 figures, LaTeX with MNRAS style file,accepted for publication in The Monthly Notices of the Royal Astron.So

Genetic diversity in Spanish donkey breeds using microsatellite DNA markers

Genetic diversity at 13 equine microsatellite loci was compared in five endangered Spanish donkey breeds: Andaluza, Catalana, Mallorquina, Encartaciones and Zamorano-Leonesa. All of the equine microsatellites used in this study were amplified and were polymorphic in the domestic donkey breeds with the exception of HMS1, which was monomorphic, and ASB2, which failed to amplify. Allele number, frequency distributions and mean heterozygosities were very similar among the Spanish donkey breeds. The unbiased expected heterozygosity (HE) over all the populations varied between 0.637 and 0.684 in this study. The low GST value showed that only 3.6% of the diversity was between breeds (P < 0.01). Significant deviations from Hardy-Weinberg equilibrium were shown for a number of locus-population combinations, except HMS5 that showed agreement in all analysed populations. The cumulative exclusion probability (PE) was 0.999 in each breed, suggesting that the loci would be suitable for donkey parentage testing. The constructed dendrogram from the DA distance matrix showed little differentiation between Spanish breeds, but great differentiation between them and the Moroccan ass and also with the horse, used as an outgroup. These results confirm the potential use of equine microsatellite loci as a tool for genetic studies in domestic donkey populations, which could also be useful for conservation plans

Distributional concerns in managers’ compensation schemes for heterogeneous workers: experimental evidence

We present results from three-player experiments aimed at studying distributional concerns in how ownermanagers compensate themselves and workers of different productivities and effort costs, as well as their relations to various equity principles. We are also interested in how owner-managers decisions’ are affected by pay secrecy. We use a game in which workers first exert effort and owner-managers then decide on bonuses for themselves and workers. Our design includes four treatments: 1) different productivities of workers with complete information; 2) different productivities of workers with pay secrecy among workers; 3) different effort cost of workers with complete information; and 4) different effort cost of workers with pay secrecy among workers. The equity principles we focus on are ‘production-equity’, higher production leads to higher wage, and ‘effort-cost equity’, higher effort-cost leads to higher wage. Our results show that, on average, managers do not pay relative wages in accordance to relative production levels, but also take effort-cost into account. Pay secrecy affects compensation differences among workers in a limited way. Across all treatments about 50% of all manager choices are compatible both with ‘production equity’ and with ‘effort- cost equity’, about 20% only with production equity and about 15% only with effort-cost equity

Semianalytical Approach to the PDF of SINR in HPHT and LPLT Single-Frequency Networks

(c) 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this[EN] Single-frequency networks (SFN) are widely adopted in terrestrial broadcast networks based on high-power high-tower (HPHT) deployments. The mobile broadcasting standard Evolved Multimedia Broadcast Multicast Service (eMBMS) has been enhanced in Release 14 to enable SFN operation with larger CP duration which may allow for the deployment of large area SFNs and even the combined operation between HPHT and low-power low-tower (LPLT) cellular stations. The knowledge of the signal-to-interference-plus-noise ratio (SINR) distribution over an SFN area may facilitate the selection of transmission parameters according to the network topology. This paper presents a semianalytical method for the calculation of the SINR distribution in SFNs with low computational complexity compared to Monte Carlo simulations. The method, which builds on previous work developed for cellular communications, is applied to HPHT+LPLT SFNs and evaluated against different transmission and network parameters.This work was supported in part by the Ministerio de Educacion y Ciencia, Spain, under Grant TEC2014-56483-R, in part by European FEDER funds.Gimenez Gandia, JJ.; Sung, KW.; Gomez-Barquero, D. (2018). Semianalytical Approach to the PDF of SINR in HPHT and LPLT Single-Frequency Networks. IEEE Transactions on Vehicular Technology. 67(5):4173-4181. https://doi.org/10.1109/TVT.2018.2791347S4173418167

Curvature Sensing by a Viral Scission Protein

Membrane scission is the final step in all budding processes wherein a membrane neck is sufficiently constricted so as to allow for fission and the release of the budded particle. For influenza viruses, membrane scission is mediated by an amphipathic helix (AH) domain in the viral M2 protein. While it is known that the M2AH alters membrane curvature, it is not known how the protein is localized to the center neck of budding virions where it would be able to cause membrane scission. Here, we use molecular dynamics simulations on buckled lipid bilayers to show that the M2AH senses membrane curvature and preferentially localizes to regions of high membrane curvature, comparable to that seen at the center neck of budding influenza viruses. These results were then validated using in vitro binding assays to show that the M2AH senses membrane curvature by detecting lipid packing defects in the membrane. Our results show that the M2AH senses membrane curvature and suggest that the AH domain may localize the protein at the viral neck where it can then mediate membrane scission and the release of budding viruses

Wideband Broadcasting: A Power-Efficient Approach to 5G Broadcasting

(c) 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this[EN] Efficient and flexible use of spectrum will be inherent characteristics of fifth-generation (5G) communication technologies with native support of wideband operation with frequency reuse 1, i.e. all transmit sites use all available frequency resources. Although not from the very first 5G release of 3GPP (Third Generation Partnership Project), it is expected that broadcast/multicast technology components will later be added and fully integrated in the 5G system. The combination of both wideband and frequency reuse 1 may provide significant gains for broadcast transmissions in terms of energy efficiency, since it is more efficient to increase capacity by extending the bandwidth rather than increasing the transmit power over a given bandwidth. This breaks with the traditional concept of terrestrial broadcast frequency planning, and paves the way to new potential uses of UHF (Ultra High Frequency) spectrum bands for 5G broadcasting. This paper provides an insight into the fundamental advantages in terms of capacity, coverage as well as power saving of wideband broadcast operation. The role of the network deployment, linked to frequency reuse in the UHF band, and its influence in the performance of a Wideband Broadcasting system are discussed. The technical requirements and features that would enable such power-efficient solution are also addressed.This work was supported in part by the European Commission under the 5G-PPP project 5G-Xcast (H2020-ICT-2016-2 call, grant number 761498). The views expressed in this contribution are those of the authors and do not necessarily represent the project. This work was also partially supported by the Ministerio de Educacion y Ciencia, Spain (TEC2014-56483-R), co-funded by European FEDER funds.Gimenez Gandia, JJ.; Gomez-Barquero, D.; Mogarde, J.; Stare, E. (2018). Wideband Broadcasting: A Power-Efficient Approach to 5G Broadcasting. IEEE Communications Magazine. 56(3):119-125. https://doi.org/10.1109/MCOM.2018.170067511912556

Scattered Pilot Performance and Optimization for ATSC 3.0

[EN] The next-generation U.S. digital terrestrial television (DTT) standard ATSC 3.0 is the most flexible DTT standard ever developed, outperforming the state-of-the-art digital video broadcasting-terrestrial 2nd generation (DVB-T2) standard. This higher flexibility allows broadcasters to select the configuration that better suits the coverage and capacity requirements per service. Regarding the selection of pilot patterns, whereas DVB-T2 provides eight different patterns with a unique pilot amplitude, ATSC 3.0 expands up to 16, with five different amplitudes per pattern. This paper focuses on the pilot pattern and amplitude performance and optimization for time and power multiplexing modes, time division multiplexing and layered division multiplexing (LDM), respectively, of ATSC 3.0. The selection of the optimum pilot configuration is not straightforward. On the one hand, the pilots must be sufficiently dense to follow channel fluctuations. On the other hand, as long as pilot density is increased, more data overhead is introduced. Moreover, this selection is particularly essential in LDM mode, because the LDM implementation in ATSC 3.0 requires that both layers share all the waveform parameters, including pilot pattern configuration. In addition, there is an error proportional to the channel estimate of the top layer that affects to the lower layer performance.This work was supported in part by the Institute for Information and Communications Technology (IITP) by the Korea Government (MSIP) (Development of Service and Transmission Technology for Convergent Realistic Broadcast) under Grant R0101-15-294, and in part by the Ministerio de Educación y Ciencia, Spain, by European FEDER Funds under Grant TEC2014-56483-R.Garro, E.; Gimenez, JJ.; Park, SI.; Gomez-Barquero, D. (2017). Scattered Pilot Performance and Optimization for ATSC 3.0. IEEE Transactions on Broadcasting. 63(1):282-292. https://doi.org/10.1109/TBC.2016.2630304S28229263

Vertical Mapping of Auditory Loudness: Loud is High, but Quiet is not Always Low

Although the perceptual association between verticality and pitch has been widely studied, the link between loudness and verticality is not fully understood yet. While loud and quiet sounds are assumed to be equally associated crossmodally with spatial elevation, there are perceptual differences between the two types of sounds that may suggest the contrary. For example, loud sounds tend to generate greater activity, both behaviourally and neurally, than quiet sounds. Here we investigated whether this difference percolates into the crossmodal correspondence between loudness and verticality. In an initial phase, participants learned one-to-one arbitrary associations between two tones differing in loudness (82dB vs. 56dB) and two coloured rectangles (blue vs. yellow). During the experimental phase, they were presented with the two-coloured stimuli (each one located above or below a central "departure" point) together with one of the two tones. Participants had to indicate which of the two-coloured rectangles corresponded to the previously-associated tone by moving a mouse cursor from the departure point towards the target. The results revealed that participants were significantly faster responding to the loud tone when the visual target was located above (congruent condition) than when the target was below the departure point (incongruent condition). For quiet tones, no differences were found between the congruent (quiet-down) and the incongruent (quiet-up) conditions. Overall, this pattern of results suggests that possible differences in the neural activity generated by loud and quiet sounds influence the extent to which loudness and spatial elevation share representational content