A Review on the Cosmology of the de Sitter Horndeski Models

We review the most general scalar-tensor cosmological models with up to second-order derivatives in the field equations that have a fixed spatially flat de Sitter critical point independent of the material content or vacuum energy. This subclass of the Horndeski Lagrangian is capable of dynamically adjusting any value of the vacuum energy of the matter fields at the critical point. We present the cosmological evolution of the linear models and the non-linear models with shift symmetry. We come to the conclusion that the shift symmetric non-linear models can deliver a viable background compatible with current observations.Comment: 7 pages, 2 figures. Proceedings accepted for publication in "Universe", Special Issue "Varying Constants and Fundamental Cosmology" for the VARCOSMOFUN16 in Szczecin, Poland, 12-17 September, 201

Slotting Allowance: an Overlooked Angle in Grocery Retailing

Ever wonder why one product brand enjoys a more prominent shelf location in a particular retail establishment than another brand? Would such arrangement have any impact on the price one pays for a particular product? Answers to these are related to the relatively unexplored business phenomenon known as slotting allowances or fees for store shelf space. Read more about it...slotting allowance, retail market, distribution market, intermediate market, shelf space rental fee, product brand, store shelf space

Impacto da temperatura na manutenção dos simbiontes associados aos cecos gástricos de percevejos.

Abstract: Impacts of climate change may affect population performance directly or indirectly through mediated effects on their mutualists. Recently, my colleagues and I showed that the stink bugs species Nezara viridula, Acrosternum hilare, Murgantia histrionica harbor a dominant caecum-associated symbiont. We detected the symbionts presence in the gastric caecum through PCR (Polymerase chain reaction) by using specific primers and monitored the demographic parameters of the insects rearing them at 25 and 30°C. High temperature (30ºC) eliminated the caeca-associated symbionts of A. hilare and M. histrionica. Mortality of A. hilare was substantially higher at 30°C in the first generation, however M. histrionica only started to show higher mortality at 30°C during second generation. Here I present the data of Prado et al. (2010) which showed that host fitness was potentially mediated by symbiont loss at 30°C, and that climate changes can have influence on the host's development, ecology, and geographic localization

Alcohol-Induced Histone Acetylation Reveals a Gene Network Involved in Alcohol Tolerance

Alfredo Ghezzi, Harish R. Krishnan, Linda Lew, Francisco J. Prado III, Darryl S. Ong, Nigel S. Atkinson, Section of Neurobiology and Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, Texas, United States of AmericaSustained or repeated exposure to sedating drugs, such as alcohol, triggers homeostatic adaptations in the brain that lead to the development of drug tolerance and dependence. These adaptations involve long-term changes in the transcription of drug-responsive genes as well as an epigenetic restructuring of chromosomal regions that is thought to signal and maintain the altered transcriptional state. Alcohol-induced epigenetic changes have been shown to be important in the long-term adaptation that leads to alcohol tolerance and dependence endophenotypes. A major constraint impeding progress is that alcohol produces a surfeit of changes in gene expression, most of which may not make any meaningful contribution to the ethanol response under study. Here we used a novel genomic epigenetic approach to find genes relevant for functional alcohol tolerance by exploiting the commonalities of two chemically distinct alcohols. In Drosophila melanogaster, ethanol and benzyl alcohol induce mutual cross-tolerance, indicating that they share a common mechanism for producing tolerance. We surveyed the genome-wide changes in histone acetylation that occur in response to these drugs. Each drug induces modifications in a large number of genes. The genes that respond similarly to either treatment, however, represent a subgroup enriched for genes important for the common tolerance response. Genes were functionally tested for behavioral tolerance to the sedative effects of ethanol and benzyl alcohol using mutant and inducible RNAi stocks. We identified a network of genes that are essential for the development of tolerance to sedation by alcohol.This work was supported by National Institute of Health grant R01 AA018037 to NSA (http://www.nih.gov/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.NeuroscienceWaggoner Center for Alcohol and Addiction ResearchEmail: [email protected] (AG)Email: [email protected] (NSA

Periodic orbit bifurcations and scattering time delay fluctuations

We study fluctuations of the Wigner time delay for open (scattering) systems which exhibit mixed dynamics in the classical limit. It is shown that in the semiclassical limit the time delay fluctuations have a distribution that differs markedly from those which describe fully chaotic (or strongly disordered) systems: their moments have a power law dependence on a semiclassical parameter, with exponents that are rational fractions. These exponents are obtained from bifurcating periodic orbits trapped in the system. They are universal in situations where sufficiently long orbits contribute. We illustrate the influence of bifurcations on the time delay numerically using an open quantum map.Comment: 9 pages, 3 figures, contribution to QMC200