1,030 research outputs found

    Confidence in assessing the effectiveness of bath treatments for the control of sea lice on Norwegian salmon farms

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    The salmon louse Lepeophtheirus salmonis is the most important ectoparasite of farmed salmonids in the Northern hemisphere, having a major economic and ecological impact on the sustainability of this sector of the aquaculture industry. To a large extent, control of L. salmonis relies on the use of topical delousing chemical treatments in the form of baths. Improvements in methods for the administration and assessment of bathtreatments have not kept pace with the rapid modernization and intensification of the salmon industry. Bathtreatments present technical and biological challenges, including best practice methods for the estimation of the effect of licetreatment interventions. In this communication, we compare and contrast methods to calculate and interpret treatmenteffectiveness at pen and site level. The methods are illustrated for the calculation of the percentage reduction in mean abundance of mobile lice with a measure of confidence. Six different methods for the calculation of confidence intervals across different probability levels were compared. We found the quasi-Poisson method with a 90% confidence interval to be informative and robust for the measurement of bathtreatment performance

    Multivariate evaluation of the effectiveness of treatment efficacy of cypermethrin against sea lice (Lepeophtheirus salmonis) in Atlantic salmon (Salmo salar)

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    Background: The sea louse Lepeophtheirus salmonis is the most important ectoparasite of farmed Atlantic salmon (Salmo salar) in Norwegian aquaculture. Control of sea lice is primarily dependent on the use of delousing chemotherapeutants, which are both expensive and toxic to other wildlife. The method most commonly used for monitoring treatment effectiveness relies on measuring the percentage reduction in the mobile stages of Lepeophtheirus salmonis only. However, this does not account for changes in the other sea lice stages and may result in misleading or incomplete interpretation regarding the effectiveness of treatment. With the aim of improving the evaluation of delousing treatments, we explored multivariate analyses of bath treatments using the topical pyrethroid, cypermethrin, in salmon pens at five Norwegian production sites.Results: Conventional univariate analysis indicated reductions of over 90% in mobile stages at all sites. In contrast, multivariate analyses indicated differing treatment effectiveness between sites (p-value < 0.01) based on changes in the proportion and abundance of the chalimus and PAAM (pre-adult and adult males) stages. Low water temperatures and shortened intervals between sampling after treatment may account for the differences in the composition of chalimus and PAAM stage groups following treatment. Using multivariate analysis, such factors could be separated from those which were attributable to inadequate treatment or chemotherapeutant failure.Conclusions: Multivariate analyses for evaluation of treatment effectiveness against multiple life cycle stages of L. salmonis yield additional information beyond that derivable from univariate methods. This can aid in the identification of causes of apparent treatment failure in salmon aquaculture

    CMB Anomalies from Imperfect Dark Energy: Confrontation with the Data

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    We test anisotropic dark energy models with the 7-year WMAP temperature observations data. In the presence of imperfect sources, due to large-scale gradients or anisotropies in the dark energy field, the CMB sky will be distorted anisotropically on its way to us by the ISW effect. The signal covariance matrix then becomes nondiagonal for small multipoles, but at 20\ell \gtrsim 20 the anisotropy is negligible. We parametrize possible violations of rotational invariance in the late universe by the magnitude of a post-Friedmannian deviation from isotropy and its scale dependence. This allows to obtain hints on possible imperfect nature of dark energy and the large-angle anomalous features in the CMB. A robust statistical analysis, subjected to various tests and consistency checks, is performed to compare the predicted correlations with those obtained from the satellite-measured CMB full sky maps. The preferred axis point towards (l,b)=(168,31)(l,b) = (168^\circ, -31^\circ) and the amplitude of the anisotropy is ϖ0=(0.51±0.94)\varpi_0 = (0.51\pm 0.94) (1σ\sigma deviation quoted). The best-fit model has a steep blue anisotropic spectrum (nde=3.1±1.5n_{\mathrm{de}} = 3.1\pm1.5).Comment: 11 pages, 4 figure

    24-hour changes in circulating prolactin, follicle-stimulating hormone, luteinizing hormone and testosterone in male rats subjected to social isolation

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    BACKGROUND: This work analyzes the effect of social isolation (a mild stressor) on the 24-h variation of pituitary-testicular function in young Wistar rats, assessed by measuring circulating levels of prolactin, FSH, LH and testosterone. METHODS: Animals were either individually caged or kept in groups (4–5 animals per cage) under a 12:12 h light-dark cycle (lights on at 0800 h) for 30 days starting on day 35 of life. Rats were killed at 4-h intervals during a 24-h cycle, beginning at 0900 h. RESULTS: Isolation brought about a decrease in prolactin, LH and testosterone secretion and an increase of FSH secretion. In isolated rats the 24-h secretory pattern of prolactin and testosterone became modified, i.e., the maximum in prolactin seen in control animals at the beginning of the activity span was no longer detected, whereas the maximum in circulating testosterone taking place at 1700 h in controls was phase-delayed to 2100 h in isolated rats. CONCLUSION: Social isolation affects the 24-h variation of pituitary-testicular function in young rats. Secretion of prolactin, LH and testosterone decreases, and secretion of FSH increases, in isolated rats. The maximum in prolactin seen in group-caged rats at the beginning of the activity span is not observed in isolated rats. The maximum in circulating testosterone taking place at the second part of the rest span in controls is phase-delayed to the light-dark transition in isolated rats

    Volúmenes molares aparentes de los anestésicos procaína-HCl y lidocaína-HCl en agua a temperaturas entre 278,15 y 313,15 K

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    La lidocaína-HCl y procaína-HCl son anestésicos locales ampliamente usados en procedimientos quirúrgicos menores, sin embargo la información fisicoquímica acerca de su comportamiento volumétrico, así como de otras propiedades fisicoquímicas, aún es incompleta en la actualidad. Por esta razón, en este artículo se presentan los valores de densidad de algunas soluciones acuosas de estos dos fármacos en función de la concentración (desde 0,0500 hasta 0,5000) mol kg–1 a diferentes temperaturas (278,15, 283,15, 288,15, 293,15, 298,15, 303,15, 308,15 y 313,15 K). Así mismo se presentan los volúmenes molares aparentes y volúmenes molares parciales a dilución infinita de los fármacos como electrolitos, y de otro lado, los volúmenes molares parciales a dilución infinita de los fármacos moleculares y las expansibilidades molares, los cuales fueron calculados a partir de los valores de densidad y composición de las mezclas. Los resultados obtenidos se interpretan en términos de interacciones soluto-solvente.Lidocaine-HCl and procaine-HCl are local anesthetic drugs widely used in minor chirurgic procedures, nevertheless, physicochemical information about their volumetric behavior, as well as for other aqueous properties, is not complete at present. In this context, in this article, densities of aqueous solutions of both drugs have been measured as a function of concentration (from 0.0500 to 0.5000) mol kg–1 at several temperatures, i.e. 278.15, 283.15, 288.15, 293.15, 298.15, 303.15, 308.15, and 313.15 K. The apparent molar volumes and partial molar volumes at infinite dilution for the electrolyte drugs were calculated, whereas, the partial molar volumes at infinite dilution and partial molar expansibilities for the molecular forms were also calculated. The dependence of these properties with temperature is shown. The results are interpreted in terms of interaction solute-solvent.Fil: Delgado, Daniel R.. Universidad Nacional de Colombia; ColombiaFil: Jimenez Kairuz, Alvaro Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Farmacia; ArgentinaFil: Manzo, Ruben Hilario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Farmacia; ArgentinaFil: Vargas, Edgar F.. Universidad de los Andes; ColombiaFil: Martinez, Fleming. Universidad Nacional de Colombia; Colombi

    Improved Cosmological Parameter Constraints from CMB and H(z) Data

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    We discuss the cosmological degeneracy between the Hubble parameter H(z), the age of the universe and cosmological parameters describing simple variations from the minimal LCDM model. We show that independent determinations of the Hubble parameter H(z) such as those recently provided by Simon et al., Phys. Rev. D 71 (2005) 123001, combined with Cosmic Microwave Background data, can provide stringent constraints on possible deviations from the LCDM model. In particular we find that this data combination constrains at the 68% (95%) confidence level the following parameters: sum of the neutrino masses < 0.5 (1.0) eV, number of relativistic neutrino species N_rel = 4.1^{+0.4}_{-0.9} (^{+1.1}_{-1.5}), dark energy equation of state parameter w = -0.95 +- 0.17 (+- 0.32), and curvature \Omega_k = 0.002 +- 0.006 (+- 0.014), in excellent agreement with dataset combinations involving Cosmic Microwave Background, Supernovae and Baryon Acoustic Oscillations. This offers a valuable consistency check for systematic errors.Comment: 10 pages, 7 figures. Added references. Minor changes added to match accepted version in JCA

    RecVAE: a New Variational Autoencoder for Top-N Recommendations with Implicit Feedback

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    Recent research has shown the advantages of using autoencoders based on deep neural networks for collaborative filtering. In particular, the recently proposed Mult-VAE model, which used the multinomial likelihood variational autoencoders, has shown excellent results for top-N recommendations. In this work, we propose the Recommender VAE (RecVAE) model that originates from our research on regularization techniques for variational autoencoders. RecVAE introduces several novel ideas to improve Mult-VAE, including a novel composite prior distribution for the latent codes, a new approach to setting the β\beta hyperparameter for the β\beta-VAE framework, and a new approach to training based on alternating updates. In experimental evaluation, we show that RecVAE significantly outperforms previously proposed autoencoder-based models, including Mult-VAE and RaCT, across classical collaborative filtering datasets, and present a detailed ablation study to assess our new developments. Code and models are available at https://github.com/ilya-shenbin/RecVAE.Comment: In The Thirteenth ACM International Conference on Web Search and Data Mining (WSDM '20), February 3-7, 2020, Houston, TX, USA. ACM, New York, NY, USA, 9 page

    PICALM modulates autophagy activity and tau accumulation.

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    Genome-wide association studies have identified several loci associated with Alzheimer's disease (AD), including proteins involved in endocytic trafficking such as PICALM/CALM (phosphatidylinositol binding clathrin assembly protein). It is unclear how these loci may contribute to AD pathology. Here we show that CALM modulates autophagy and alters clearance of tau, a protein which is a known autophagy substrate and which is causatively linked to AD, both in vitro and in vivo. Furthermore, altered CALM expression exacerbates tau-mediated toxicity in zebrafish transgenic models. CALM influences autophagy by regulating the endocytosis of SNAREs, such as VAMP2, VAMP3 and VAMP8, which have diverse effects on different stages of the autophagy pathway, from autophagosome formation to autophagosome degradation. This study suggests that the AD genetic risk factor CALM modulates autophagy, and this may affect disease in a number of ways including modulation of tau turnover.We are grateful for funding from a Wellcome Trust Principal Research Fellowship (D.C.R.), a Wellcome Trust/MRC Strategic Grant on Neurodegeneration (D.C.R., C.J.O’.K.), a Wellcome Trust Strategic Award to Cambridge Institute for Medical Research, Wellcome Trust Studentship (E.Z.), the Alzheimer’s disease Biomedical Research Unit and Addenbrooke’s Hospital, the Tau Consortium, a fellowship from University of Granada (A.L.R.), a V Foundation/Applebee’s Research Grant (D.S.W.) and NCI R01 CA 109281 (D.S.W.).This is the final published version. It is also available from Nature Publishing at http://www.nature.com/ncomms/2014/140922/ncomms5998/full/ncomms5998.html
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