4,627 research outputs found

    Evaluation of resampling applied to UAV imagery for weed detection using OBIA

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    Los vehículos aéreos no tripulados (UAVs) son una tecnología emergente en el estudio de parámetros agrícolas por sus características y por portar sensores en diferente rango espectral. En este trabajo se ha detectado y cartografiado rodales de malas hierbas en fase temprana mediante análisis OBIA para elaborar mapas que optimicen el tratamiento herbicida localizado. Se ha aplicado resampling (resampleo) sobre imágenes tomadas en campo desde un UAV (UAV-I) para crear una nueva imagen con distinta resolución espacial. A las imágenes resampleadas (RS-I) se les evaluó la calidad espacial y espectral y la eficacia de nuestro análisis en la detección de malas hierbas. Los resultados de las imágenes RS-I muestran una precisión similar a las imágenes UAV-I siendo factible su utilización en tecnologías de manejo localizado de malas hierbas. Se discuten las ventajas del uso de la técnica de resampling en imágenes UAV.Unmanned aerial vehicles (UAV) are an emerging technology for the study of agriculture parameters due to its characteristics and the availability of embedding sensors with different spectral range. In our study, the detection and mapping of weeds in early phenological stage allowed to design a strategy for the optimizing of herbicide treatment. In this work, resampling is used to create a new version of an image with a different spatial resolution, using real UAV imagery. A spatial and spectral quality evaluation was carried out to resampled images (RS-I), and then, our workflow for weed detection applied. The results showed that RS-I and UAV-I showed similar accuracy on weed detection and thus could be used for site-specific weed management achieving a percentage of savings in the herbicide. Opportunities of using RS-I are discussed

    Supervivencia y longevidad de las libélulas del neotrópico (Odonata, Polythoridae)

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    Survival and longevity in neotropical damselflies (Odonata, Polythoridae). Longevity among insect orders varies greatly, and has mainly been studied in insects in temperate biomes, where seasonality determines high synchronization of reproductive activities and limits lifespan. Most forest damselflies in tropical regions have low population densities and are almost never observed in copula. We hypothesized that selection will favour a high survival rate and hence high lifespan, allowing the animals to be ready for the occasional events that favour reproduction. We studied two neotropical damselflies, Polythore mutata and P. derivata, in Ecuador, using mark–recapture methods. We found that sex affected the rate of recapture, but daily survival rate was affected by sex only in one population. We found evidence that suggests stabilizing or directional selection on body size. The maximum lifespan was 54–63 days. We conclude that the survival rate of Polythore damselflies in tropical forests is comparable to that of similar damselflies in temperate zones. © 2019. Museu de Ciències Naturals de Barcelona. All rights reserved

    Pesticide Exposure Alters Follicle-Stimulating Hormone Levels in Mexican Agricultural Workers

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    Organophosphorous pesticides (OPs) are suspected of altering reproductive function by reducing brain acetylcholinesterase activity and monoamine levels, thus impairing hypothalamic and/or pituitary endocrine functions and gonadal processes. Our objective was to evaluate in a longitudinal study the association between OP exposure and serum levels of pituitary and sex hormones. Urinary OP metabolite levels were measured by gas–liquid chromatography, and serum pituitary and sex hormone levels by enzymatic immunoassay and radioimmunoassay in 64 men. A total of 147 urine and blood samples were analyzed for each parameter. More than 80% of the participants had at least one OP metabolite in their urine samples. The most frequent metabolite found was diethylthiophosphate (DETP; 55%), followed by diethylphosphate (DEP; 46%), dimethylthiophosphate (DMTP; 32%), and dimethyldithiophosphate (DMDTP; 31%). However, the metabolites detected at higher concentrations were DMTP, DEP, DMDTP, and dimethylphosphate. There was a high proportion of individuals with follicle-stimulating hormone (FSH) concentrations outside the range of normality (48%). The average FSH serum levels were higher during the heavy pesticide spraying season. However, a multivariate analysis of data collected in all periods showed that serum FSH levels were negatively associated with urinary concentrations of both DMTP and DMDTP, whereas luteinizing hormone (LH) was negatively associated with DMTP. We observed no significant associations between estradiol or testosterone serum levels with OP metabolites. The hormonal disruption in agricultural workers presented here, together with results from experimental animal studies, suggests that OP exposure disrupts the hypothalamic–pituitary endocrine function and also indicates that FSH and LH are the hormones most affected

    Nosocomial outbreak of Pseudomonas aeruginosa endophthalmitis

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    We describe an outbreak of nosocomial endophthalmitis due to a common source, which was determined to be trypan blue solution prepared in the hospital's pharmacy service. We assume that viable bacteria probably gained access to the trypan blue stock solution during cooling after autoclaving. The temporal cluster of Pseudomonas aeruginosa endophthalmitis was readily perceived on the basis of clinical and microbiological findings, and an exogenous source of contamination was unequivocally identified by means of DNA fingerprinting. © 2006 by The Society for Healthcare Epidemiology of America. All rights reserved

    Removal of Sb Impurities in Copper Electrolyte and Evaluation of as and Fe Species in an Electrorefining Plant

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    Antimony and arsenic concentrations and their oxidation states (Sb(III), Sb(V), As(III) and As(V)) in copper electrorefining electrolyte can affect copper cathode quality through the formation of floating slimes. A laboratory-scale pilot plant was operated to remove Sb from commercial electrolyte. The pilot plant consisted of a pre-treatment process with copper shavings followed by ion exchange. The results indicated that Sb(III) was removed from copper electrolyte completely, while Sb(V) was partially eliminated. The concentrations of As(III) and As(V) were not affected, and the poisoning of the ion exchange resin by Fe(III) was avoided by pre-reduction to Fe(II) by copper shavings. The operation configuration of the pilot plant was applied to the design of an industrial plant for Sb/Bi removal at the Atlantic Copper Refinery in Huelva, Spain. The evolution of Sb, Fe and As species in the commercial electrolyte was monitored prior to and after the installation of the Sb/Bi removal plant. The results show a ca. 45% decrease in total Sb content (from 0.29 g L−1 to 0.16 g L−1) in the electrolyte. This reduction is more noticeable for Sb(III), whose concentration decreased from 0.18 g L−1 to 0.09 g L−1, whereas Sb(V) concentration diminished from 0.11 g L−1 to 0.07 g L−1. The resin also retained ca. 75% of the Bi content (0.15-0.22 g L−1). The total As increased during the study period (from 7.7 to 9.0 g L−1) due to changes in plant inputs. Arsenic was predominantly As(V) (ca. 93-95%). The total Fe concentration experienced little variation (0.9-1.1 g L−1) with Fe(II) being the main species (ca. 94-96%)

    Stiff monatomic gold wires with a spinning zigzag geometry

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    Using first principles density functional calculations, gold monatomic wires are found to exhibit a zigzag shape which remains under tension, becoming linear just before breaking. At room temperature they are found to spin, what explains the extremely long apparent interatomic distances shown by electron microscopy.The zigzag structure is stable if the tension is relieved, the wire holding its chainlike shape even as a free-standing cluster. This unexpected metallic-wire stiffness stems from the transverse quantization in the wire, as shown in a simple free electron model.Comment: 4 pages, latex, 5 figures, submitted to PR

    Efficacy of modern antipsychotics in placebo-controlled trials in bipolar depression: a meta-analysis.

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    Randomized, controlled trials have demonstrated efficacy for second-generation antipsychotics in the treatment of acute mania in bipolar disorder. Despite depression being considered the hallmark of bipolar disorder, there are no published systematic reviews or meta-analyses to evaluate the efficacy of modern atypical antipsychotics in bipolar depression. We systematically reviewed published or registered randomized, double-blind, placebo-controlled trials (RCTs) of modern antipsychotics in adult bipolar I and/or II depressive patients (DSM-IV criteria). Efficacy outcomes were assessed based on changes in the Montgomery-Asberg Depression Rating Scale (MADRS) during an 8-wk period. Data were combined through meta-analysis using risk ratio as an effect size with a 95% confidence interval (95% CI) and with a level of statistical significance of 5% (p<0.05). We identified five RCTs; four involved antipsychotic monotherapy and one addressed both monotherapy and combination with an antidepressant. The two quetiapine trials analysed the safety and efficacy of two doses: 300 and 600 mg/d. The only olanzapine trial assessed olanzapine monotherapy within a range of 5-20 mg/d and olanzapine-fluoxetine combination within a range of 5-20 mg/d and 6-12 mg/d, respectively. The two aripiprazole placebo-controlled trials assessed doses of 5-30 mg/d. Quetiapine and olanzapine trials (3/5, 60%) demonstrated superiority over placebo (p<0.001). Only 2/5 (40%) (both aripiprazole trials) failed in the primary efficacy measure after the first 6 wk. Some modern antipsychotics (quetiapine and olanzapine) have demonstrated efficacy in bipolar depressive patients from week 1 onwards. Rapid onset of action seems to be a common feature of atypical antipsychotics in bipolar depression. Comment in The following popper user interface control may not be accessible. Tab to the next button to revert the control to an accessible version.Destroy user interface controlEfficacy of modern antipsychotics in placebo-controlled trials in bipolar depression: a meta-analysis--results to be interpreted with caution

    Diagnòstic i seguiment farmacoterapèutic de la hiperuricèmia i gota

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    Treballs d'Educació Farmacèutica als ciutadans. Unitat Docent d'Estades en Pràctiques Tutelades. Facultat de Farmàcia, Universitat de Barcelona. Curs: 2016-2017. Tutors: Anna Mas Comas i Ramón Jódar Masanés i Marian March Pujol.L’objectiu principal d’aquest treball és la cerca bibliogràfica de les diferents inquietuds que pot tenir un pacient amb hiperuricèmia o gota. Més concretament queden resumits en els següents punts: 1. Estudiar els diferents efectes de tenir una alta concentració plasmàtica d’àcid úric, quines són les causes i la prevalença dins de la població occidental general. 2. Analitzar les manifestacions clíniques associades així com el seu diagnòstic. 3. Determinar com afecten les mesures no farmacològiques i farmacològiques en el maneig de la patologia. 4. Reforçar el paper del farmacèutic en el maneig de la malalti
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