2,134 research outputs found

    Analysis of the SFR - M* plane at z<3: single fitting versus multi-Gaussian decomposition

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    The analysis of galaxies on the star formation rate - stellar mass (SFR-M*) plane is a powerful diagnostic for galaxy evolution at different cosmic times. We consider a sample of 24463 galaxies from the CANDELS/GOODS-S survey to conduct a detailed analysis of the SFR-M* relation at redshifts 0.5⩽z<\leqslant z<3 over more than three dex in stellar mass. To obtain SFR estimates, we utilise mid- and far-IR photometry when available, and rest-UV fluxes for all the other galaxies. We perform our analysis in different redshift bins, with two different methods: 1) a linear regression fitting of all star-forming galaxies, defined as those with specific star formation rates log10(sSFR/yr−1)>−9.8\rm log_{10}(sSFR/yr^{-1}) > -9.8, similarly to what is typically done in the literature; 2) a multi-Gaussian decomposition to identify the galaxy main sequence (MS), the starburst sequence and the quenched galaxy cloud. We find that the MS slope becomes flatter when higher stellar mass cuts are adopted, and that the apparent slope change observed at high masses depends on the SFR estimation method. In addition, the multi-Gaussian decomposition reveals the presence of a starburst population which increases towards low stellar masses and high redshifts. We find that starbursts make up ~5% of all galaxies at z=0.5-1.0, while they account for ~16% of galaxies at 2<z<<z<3 with log10(M∗)=_{10}(M^{*})=8.25-11.25. We conclude that the dissection of the SFR-M* in multiple components over a wide range of stellar masses is necessary to understand the importance of the different modes of star formation through cosmic time.Comment: 15 pages, 12 figures, 1 table. Accepted for publication in A&A, after addressing referee report. Main changes with respect to v1: two new appendixes to investigate the impact of redshift outliers and to test a two-Gaussian component fit to the sSFR distribution. No conclusion change

    Therapeutic effectiveness of epicranial nerve blocks on post-traumatic syndrome from head injury

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    The autor describes the case of a 53-year-old woman suffering from headache and dizziness, sometimes nausea, tinnitus in the right ear, and diffuse scalp allodynia following an occupational accident involving a head injury. Hyposensitizing treatment by anesthetic blockade at the emergence points of the epicranial nerves, which were hyperalgesic to fi nger pressure, rapidly controlled the allodynia and eventually the headache. Unexpectedly, the patient also reported reduced dizziness and resolution of the tinnitus. The unforeseen outcome highlights the unpredictable therapeutic potential of a simple and modestly invasive procedure. The neuropathophysiological interpretation is consequently very interesting

    Chlorinated auxins–how does Arabidopsis thaliana deal with them?

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    Plant hormones have various functions in plants and play crucial roles in all developmental and differentiation stages. Auxins constitute one of the most important groups with the major representative indole-3-acetic acid (IAA). A halogenated derivate of IAA, 4-chloro-indole-3-acetic acid (4-Cl-IAA), has previously been identified in Pisum sativum and other legumes. While the enzymes responsible for the halogenation of compounds in bacteria and fungi are well studied, the metabolic pathways leading to the production of 4-Cl-IAA in plants, especially the halogenating reaction, are still unknown. Therefore, bacterial flavin-dependent tryptophan-halogenase genes were transformed into the model organism Arabidopsis thaliana. The type of chlorinated indole derivatives that could be expected was determined by incubating wild type A. thaliana with different Cl-tryptophan derivatives. We showed that, in addition to chlorinated IAA, chlorinated IAA conjugates were synthesized. Concomitantly, we found that an auxin conjugate synthetase (GH3.3 protein) from A. thaliana was able to convert chlorinated IAAs to amino acid conjugates in vitro. In addition, we showed that the production of halogenated tryptophan (Trp), indole-3-acetonitrile (IAN) and IAA is possible in transgenic A. thaliana in planta with the help of the bacterial halogenating enzymes. Furthermore, it was investigated if there is an effect (i) of exogenously applied Cl-IAA and Cl-Trp and (ii) of endogenously chlorinated substances on the growth phenotype of the plants

    Assessment of blue swimmer crab recruitment and breeding stock levels in the Peel-Harvey Estuary and status of the Mandurah to Bunbury Developing Crab Fishery

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    Two projects were funded to investigate iconic blue swimmer crab stocks in the Peel-Harvey Estuary and Mandurah to Bunbury Developing Crab Fishery. One was a four year project (2007 – 2011) to undertake the following: i) determine recruitment and spawning stock levels of the crab population in the Peel-Harvey Estuary and whether the status of stocks has changed considerably in the past decade, ii) establish a commercial monitoring program to assess the length frequency and sex ratio of crabs captured by commercial fishers, and iii) develop a commercial monitoring program in the Mandurah to Bunbury Developing Crab Fishery and South West Trawl Managed Fishery. A fishery-independent study was conducted at 15 sites throughout the estuary per month between December 2007 and December 2011. Sites chosen were identical to those surveyed between 1995 and 1998, to allow historical comparisons. Additional trap sites were sampled outside the Peel-Harvey Estuary monthly from August 2008 to December 2011 to understand crab abundance, composition and movement between estuarine and oceanic waters. A second project was a 12-month recreational survey in the Peel-Harvey Estuary between November 2007 and October 2008 to provide an estimate of recreational catch and effort

    Measuring older patients’ attitudes to general practice registrars: Exploratory factor analysis of a survey instrument

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    Introduction: Training general practice registrars (GPRs) to meet the challenges of an ageing population is hampered by their relatively reduced contact with older patients and a paucity of suitable research to inform training models. This paper describes an exploratory factor analysis of a survey instrument assessing the attitudes of older patients to GPRs, as part of a project to address these concerns. Methods: The instrument was developed on the basis of a qualitative study and a literature review and distributed to 500 patients aged 60 years and over from 10 training practices in regional Australia. Responses to 22 of the survey’s Likert scale items were examined, including inter-item correlations and internal consistency (Cronbach’s alpha). Exploratory factor analysis was performed to identify domains of patients’ attitudes. Results: The response rate was 39.2% (n=196). None of the items were redundant and the scale had appropriate levels of internal consistency (Cronbach’s alpha = 0.76). The exploratory factor analysis identified three factors. Factor one, labelled ‘interpersonal trust’, explained 26.2% of the variance. Factor two accounted for 11.4% of the variance and was labelled ‘system trust’. Factor three, labelled ‘interpersonal continuity’, explained 7.5% of the variance. Conclusion: The instrument demonstrated acceptable psychometric properties and three distinct factors reflecting older patients’ attitudes toward GPRs, with trust appearing to be particularly important. The instrument appears effective in obtaining valid data, which should assist in developing improved training models. These findings warrant confirmation with a larger sample and exploration of adaptations of the instrument to be used in other contexts. Keywords: general practice registrar; post-graduate training; patient attitude

    Manual do Sistema Balanço Hídrico e Calendário Agrícola.

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    Manual do Sistema Balanço Hídrico; Explicação e observações sobre os termos empregados nas tabelas do Balanço Hídrico; Modelo Entidade Relacionamento (MER); Objetivo operacional do sistema; Diferenciamento das duas maneiras de processamento do sistema; Funcionamento; Módulo arquivos; Módulo Balanço Hídrico; Módulo Utilitário; Módulo Sobre.bitstream/item/116808/1/834.pd

    Indium selenide: An insight into electronic band structure and surface excitations

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    We have investigated the electronic response of single crystals of indium selenide by means of angle-resolved photoemission spectroscopy, electron energy loss spectroscopy and density functional theory. The loss spectrum of indium selenide shows the direct free exciton at similar to 1.3 eV and several other peaks, which do not exhibit dispersion with the momentum. The joint analysis of the experimental band structure and the density of states indicates that spectral features in the loss function are strictly related to single-particle transitions. These excitations cannot be considered as fully coherent plasmons and they are damped even in the optical limit, i.e. for small momenta. The comparison of the calculated symmetry-projected density of states with electron energy loss spectra enables the assignment of the spectral features to transitions between specific electronic states. Furthermore, the effects of ambient gases on the band structure and on the loss function have been probed

    Species-Specific Diversity of a Fixed Motor Pattern: The Electric Organ Discharge of Gymnotus

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    Understanding fixed motor pattern diversity across related species provides a window for exploring the evolution of their underlying neural mechanisms. The electric organ discharges of weakly electric fishes offer several advantages as paradigmatic models for investigating how a neural decision is transformed into a spatiotemporal pattern of action. Here, we compared the far fields, the near fields and the electromotive force patterns generated by three species of the pulse generating New World gymnotiform genus Gymnotus. We found a common pattern in electromotive force, with the far field and near field diversity determined by variations in amplitude, duration, and the degree of synchronization of the different components of the electric organ discharges. While the rostral regions of the three species generate similar profiles of electromotive force and local fields, most of the species-specific differences are generated in the main body and tail regions of the fish. This causes that the waveform of the field is highly site dependant in all the studied species. These findings support a hypothesis of the relative separation of the electrolocation and communication carriers. The presence of early head negative waves in the rostral region, a species-dependent early positive wave at the caudal region, and the different relationship between the late negative peak and the main positive peak suggest three points of lability in the evolution of the electrogenic system: a) the variously timed neuronal inputs to different groups of electrocytes; b) the appearance of both rostrally and caudally innervated electrocytes, and c) changes in the responsiveness of the electrocyte membrane
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