14 research outputs found
Dynamics and constraints of the dissipative Liouville cosmology
In this article we investigate the properties of the FLRW flat cosmological
models in which the cosmic expansion of the Universe is affected by a dilaton
dark energy (Liouville scenario). In particular, we perform a detailed study of
these models in the light of the latest cosmological data, which serves to
illustrate the phenomenological viability of the new dark energy paradigm as a
serious alternative to the traditional scalar field approaches. By performing a
joint likelihood analysis of the recent supernovae type Ia data (SNIa), the
differential ages of passively evolving galaxies, and the Baryonic Acoustic
Oscillations (BAOs) traced by the Sloan Digital Sky Survey (SDSS), we put tight
constraints on the main cosmological parameters. Furthermore, we study the
linear matter fluctuation field of the above Liouville cosmological models. In
this framework, we compare the observed growth rate of clustering measured with
those predicted by the current Liouville models. Performing a chi^2 statistical
test we show that the Liouville cosmological model provides growth rates that
match sufficiently well with the observed growth rate. To further test the
viability of the models under study, we use the Press-Schechter formalism to
derive their expected redshift distribution of cluster-size halos that will be
provided by future X-ray and Sunyaev-Zeldovich cluster surveys. We find that
the Hubble flow differences between the Liouville and the LambdaCDM models
provide a significantly different halo redshift distribution, suggesting that
the models can be observationally distinguished.Comment: 15 pages, 4 figures, 4 tables, matches version to appear in
Astroparticle Physic
Ecological adaptation in Atlantic herring is associated with large shifts in allele frequencies at hundreds of loci
Atlantic herring is widespread in North Atlantic and adjacent waters and is one of the most abundant vertebrates on earth. This species is well suited to explore genetic adaptation due to minute genetic differentiation at selectively neutral loci. Here, we report hundreds of loci underlying ecological adaptation to different geographic areas and spawning conditions. Four of these represent megabase inversions confirmed by long read sequencing. The genetic architecture underlying ecological adaptation in herring deviates from expectation under a classical infinitesimal model for complex traits because of large shifts in allele frequencies at hundreds of loci under selection
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Absorption and Safety of Topically Applied Timolol for Treatment of Chronic Cutaneous Wounds
Objective: There are no safety or absorption studies to guide topical timolol therapy for treatment of chronic wounds. This study was undertaken to address this gap. Approach: A prospective, observational, cross-sectional comparative study of timolol plasma levels in patients after topical administration to a chronic wound, compared with levels in patients after timolol ocular administration for the indication of glaucoma. Results: There was no statistically significant difference in the average plasma level of timolol in wound as compared with glaucoma patients. No bradycardia or wheezing was observed after administration. Innovation: We determined the single time point concentration of timolol in plasma 1 h after application of timolol 0.5% gel-forming solution to debrided chronic wounds, providing insight as to the safety of this emerging off-label treatment. Conclusion: The topical application of timolol for chronic wounds shares the same safety profile as the widely used application of ocular administration for glaucoma
Percepção da fala em bebês no primeiro ano de vida Speech perception in infants in their first year of life
A fala humana é um som de grande complexidade, cujo processamento perceptual, produção e relações com a linguagem e a cognição necessitam de uma análise integrada, tanto do ponto de vista do conhecimento disponÃvel como também das especificidades metodológicas. Neste artigo faz-se uma breve revisão da literatura sobre as principais aquisições e desenvolvimento da linguagem no primeiro ano de vida de bebês com desenvolvimento normal com enfoque na percepção da fala humana. Busca-se, também, analisar a ocorrência de distúrbios auditivos que podem causar alterações na percepção da fala, com possÃveis implicações para o desenvolvimento pré-lingüÃstico. Atenção especial é dada ao desenvolvimento da habilidade de percepção de fala e de linguagem em bebês com sÃndrome de Down. É analisada a predisposição, nesta população, a problemas audiológicos, sua relação com alterações no desenvolvimento de linguagem, e a tendência apresentada no primeiro ano de vida para padrões diferenciados de atenção à fala.<br>Human speech is a highly complex sound; whose perceptual processing, production and relations to language and cognition require an integrated analysis, not only from the viewpoint of available knowledge but also of its methodological specificities. This article presents a brief review of the literature on the main acquisitions and development of language in the first year of life of normally developing infants, with emphasis on speech perception. One also analyzes the occurrence of auditory disturbances in the first year of life that could jeopardize speech perception, with possible implications for pre-linguistic development. Special attention is give to the development of speech perception and language in Down syndrome infants. The predisposition to audiologic problems, its relation to impairment in the development of language, and the tendency presented in the first year of life of differential patterns of attention to speech is analyzed in this population