105 research outputs found

    Not all features are created equal: Processing asymmetries between location and object features

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    Previous research has shown spontaneous location processing when location is not a task relevant feature and when a target is presented together with distractors. The present study investigates whether such processing can occur in the absence of distractor inhibition, and whether there is a processing asymmetry between location and an object feature. The results show that not all features are created equal. Whereas attending to an object’s color or texture led to the involuntary processing of that object’s location, attending to an object’s location did not necessarily result in the encoding of its color or texture when these nonspatial properties were not task relevant. These results add to the body of evidence demonstrating the special role of location in attentional selection. They also provide a clearer picture of the interactions among location, object features, and participants’ behavioral goals

    Fast determination of voriconazole in oral fluid using microextractionby packed sorbent and HPLC with fluorescence detection

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    A fast and reliable method for the determination of voriconazole in oral fluid using microextraction by packed sorbent and liquid chromatography with fluorescence detection was developed and validated. MEPS was performed at basic pH with only 50 μL of oral fluid and the extract was injected without an evaporation step. The overall procedure, including extraction and chromatographic analysis, took only 15 min. Voriconazole and internal standard were separated on a Lichrospher RP 8ec column (250 x 4 mm, particle diameter 5 μm) eluted with a mobile phase composed of phosphate pH 2.3 (containing 0.1 % triethylamine) and acetonitrile (64:36, v/v) at a flow rate of 1.4 mL min-1 . Total run time was 11 min, with detection being performed with excitation at 254 and emission at 372 nm. The method was successfully applied to oral fluid samples, with voriconazole concentrations presenting an average of 57.6 % of those measured in paired plasma samples.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Multicenter prevalence study comparing molecular and toxin assays for clostridioides difficile surveillance, Switzerland

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    Public health authorities in the United States and Europe recommend surveillance for Clostridioides difficile infections among hospitalized patients, but differing diagnostic algorithms can hamper comparisons between institutions and countries. We compared surveillance based on detection of C. difficile by PCR or enzyme immunoassay (EIA) in a nationwide C. difficile prevalence study in Switzerland. We included all routinely collected stool samples from hospitalized patients with diarrhea in 76 hospitals in Switzerland on 2 days, 1 in winter and 1 in summer, in 2015. EIA C. difficile detection rates were 6.4 cases/10,000 patient bed-days in winter and 5.7 cases/10,000 patient bed-days in summer. PCR detection rates were 11.4 cases/10,000 patient bed-days in winter and 7.1 cases/10,000 patient bed-days in summer. We found PCR used alone increased reported C. difficile prevalence rates by <= 80% compared with a 2-stage EIA-based algorithm.Molecular basis of bacterial pathogenesis, virulence factors and antibiotic resistanc

    Gravitomagnetism in teleparallel gravity

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    The assumption that matter charges and currents could generate fields, which are called, by analogy with electromagnetism, gravitoeletric and gravitomagnetic fields, dates from the origins of General Relativity (GR). On the other hand, the Teleparallel Equivalent of GR (TEGR), as a gauge theory, seems to be the ideal scenario to define these fields, based on the gauge field strength components. The purpose of the present work is to investigate the nature of the gravitational electric and magnetic fields in the context of the TEGR, where the tetrad formalism behind it seems to be more appropriated to deal with phenomena related to observers. As our main results, we have obtained, for the first time, the exact expressions for the gravito-electromagnetic fields for the Schwarzschild solution that in the linear approximation become the usual expected ones. To improve our understanding about these fields, we have also studied the geometry produced by a spherical rotating shell in slow motion and weak field regime. Again, the expressions obtained are in complete agreement with those of electromagnetism.Comment: 25 pages. Submitted to International Journal of Modern Physics D. Version 2: some new discussions, references adde

    Spin-2 fields and helicity

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    By considering the irreducible representations of the Lorentz group, an analysis of the different spin-2 waves is presented. In particular, the question of the helicity is discussed. It is concluded that, although from the point of view of representation theory there are no compelling reasons to choose between spin-2 waves with helicity = + - 1 or helicity = + - 2, consistency arguments of the ensuing field theories favor waves with helicity = + - 1.Comment: 10 pages. V2: presentation changes and discussion adde

    Caracterização dos produtores e dos sistemas de produção de leite no perímetro irrigado de Petrolina/PE.

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    RESUMO - Objetivou-se conhecer alguns aspectos sociais, níveis tecnológicos e resultados econômicos de produtores de leite de vaca em propriedades situadas no Perímetro Irrigado Senador Nilo Coelho, localizado no município de Petrolina, estado de Pernambuco. Foram entrevistados 28 produtores no perímetro, no período de abril a setembro do ano de 2007. As famílias dos produtores que residem nos estabelecimentos rurais e na zona urbana somaram 53,6 e 46,4%, respectivamente. As propriedades estudadas foram classificadas em sua maioria como sistemas intensivos a pasto e em confinamento (57,1%) com produção média de 9,3L/vaca/dia. A renda bruta proveniente do leite foi de R2.477,47.Arelac\ca~oentrevacasemlactac\ca~oeototaldevacaseointervalodepartosforamrespectivamentede52,12.477,47. A relação entre vacas em lactação e o total de vacas e o intervalo de partos foram respectivamente de 52,1% e 19,1 meses. Foi possível observar que, na maior parte das propriedades trabalhava-se com monta natural (96,4%) e ordenha manual (96,4%). De um modo geral a vacinação é deficiente, contudo 96,4% das propriedades vacinam contra aftosa. A principal fonte de informação desses produtores é a televisão. Em relação ao manejo alimentar, observou-se alta dependência de insumos externos. Os valores médios da produtividade da terra e do número de vacas em lactação por área foram de 3.722,0L/ha/ano e 1,1 vacas/ha, respectivamente. A bovinocultura leiteira apresenta potencial para complementar a renda dos produtores no Perímetro Irrigado Senador Nilo Coelho, porém são necessários investimentos para intensificação do uso dos recursos forrageiros, melhoria da qualidade do leite, manejo reprodutivo, nutricional e sanitário do rebanho, e assistência técnica aos produtores. ABSTRACT - This work aimed to evaluate social, technological levels, and economic results of dairy cattle producers on properties located in the Senator Nilo Coelho Irrigation District, located in the city of Petrolina, Pernambuco State. Twenty-eight producers were interviewed in the period from April to September of 2007. The families of the milk producers the Senator Nilo Coelho Irrigation District living in rural and urban areas amounted to 53,6 e 46,4% respectively. Rural properties were mostly classified as intensive systems (57,1%) with an average production of 9,3 L/lactating cow/day. Gross income from milk was R 2.477,47. The ratio between lactating cows and the total number of cows and calving interval were respectively 52.1% and 19,1 months. It was observed that most properties worked with natural mating (96,4%) and manual milking (96,4%). In general vaccination is deficient, however 96,4% of farms vaccinated against Food and Month Disease. Information main source from these producers is television. Regarding the feeding management, it was observed a high dependence on external inputs and the average land productivity and the number of milking cows per area were 3722,0L/ha/year and 1,1 cows/ha, respectively. Dairy cattle have a potential to supplement the producers income, but investments are needed to intensify the use of forage resources, to improve milk quality, reproductive management, nutrition and health herd and technical assistance to producers

    When Music and Long-Term Memory Interact: Effects of Musical Expertise on Functional and Structural Plasticity in the Hippocampus

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    The development of musical skills by musicians results in specific structural and functional modifications in the brain. Surprisingly, no functional magnetic resonance imaging (fMRI) study has investigated the impact of musical training on brain function during long-term memory retrieval, a faculty particularly important in music. Thus, using fMRI, we examined for the first time this process during a musical familiarity task (i.e., semantic memory for music). Musical expertise induced supplementary activations in the hippocampus, medial frontal gyrus, and superior temporal areas on both sides, suggesting a constant interaction between episodic and semantic memory during this task in musicians. In addition, a voxel-based morphometry (VBM) investigation was performed within these areas and revealed that gray matter density of the hippocampus was higher in musicians than in nonmusicians. Our data indicate that musical expertise critically modifies long-term memory processes and induces structural and functional plasticity in the hippocampus
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