442 research outputs found

    Dim Light at Night and Constant Darkness: Two Frequently Used Lighting Conditions That Jeopardize the Health and Well-being of Laboratory Rodents

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    The influence of light on mammalian physiology and behavior is due to the entrainment of circadian rhythms complemented with a direct modulation of light that would be unlikely an outcome of circadian system. In mammals, physiological and behavioral circadian rhythms are regulated by the suprachiasmatic nucleus (SCN) of the hypothalamus. This central control allows organisms to predict and anticipate environmental change, as well as to coordinate different rhythmic modalities within an individual. In adult mammals, direct retinal projections to the SCN are responsible for resetting and synchronizing physiological and behavioral rhythms to the light-dark (LD) cycle. Apart from its circadian effects, light also has direct effects on certain biological functions in such a way that the participation of the SCN would not be fundamental for this network. The objective of this review is to increase awareness, within the scientific community and commercial providers, of the fact that laboratory rodents can experience a number of adverse health and welfare outcomes attributed to commonly-used lighting conditions in animal facilities during routine husbandry and scientific procedures, widely considered as “environmentally friendly.” There is increasing evidence that exposure to dim light at night, as well as chronic constant darkness, challenges mammalian physiology and behavior resulting in disrupted circadian rhythms, neural death, a depressive-behavioral phenotype, cognitive impairment, and the deregulation of metabolic, physiological, and synaptic plasticity in both the short and long terms. The normal development and good health of laboratory rodents requires cyclical light entrainment, adapted to the solar cycle of day and night, with null light at night and safe illuminating qualities during the day. We therefore recommend increased awareness of the limited information available with regards to lighting conditions, and therefore that lighting protocols must be taken into consideration when designing experiments and duly highlighted in scientific papers. This practice will help to ensure the welfare of laboratory animals and increase the likelihood of producing reliable and reproducible results

    Enrofloxacin-based therapeutic strategy for the prevention of endometritis in susceptible mares

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    Enrofloxacin (EFX) is often used empirically to prevent uterine infections in mares in order to improve efficiency on Commercial Embryo Transfer Farms. This study investigated the uterine distribution of EFX and its metabolite ciprofloxacin (CFX) in mares and assessed the minimal inhibitory concentrations (MIC) of EFX against various common pathogens as a basis for establishing a rational dosing schedule. Plasma and uterine pharmacokinetic (PK) studies were performed in two groups (n = 5) of healthy mares following intravenous (i.v.) administration of EFX at either 2.5 and at 5 mg/kg bodyweight. Plasma and endometrial tissue samples, taken before for up to 48 h after treatment were analysed by Reverse Phase HPLC. MIC values for wild strains of Gram-negative (Escherichia coli, Pseudomonas aeruginosa) and Gram-positive bacteria (β-haemolytic streptococci) ranged from 0.25-2 and 1.5-3.0 μg/mL respectively. In terms of tissue distribution, the sum of the endometrial concentrations of the parent drug (EFX) and its active metabolite (CFX) (in terms of AUC), exceeded those in plasma by 249% and 941% following administration of EFX at 2.5 and 5 mg/kg respectively. After i.v. treatment with EFX at 5 mg/kg, endometrial concentrations of EFX and CFX above the MIC value were detected for 36-48 and 22-43 h posttreatment for Gram-negative and -positive isolates respectively. Concentrations above MIC were maintained for much shorter periods at the lower (2.5 mg/kg) treatment dose. Based on these results, a conventional dose (5 mg/kg) of EFX given prebreeding followed by two further doses at 36-48 h postbreeding are proposed as a rational strategy for using of EFX as a preventative therapy against a variety of common bacterial strains associated with equine endometritis.Fil: González, C. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias. Departamento de Fisiopatología. Laboratorio de Farmacología; ArgentinaFil: Moreno, L.. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias. Departamento de Fisiopatología. Laboratorio de Farmacología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fumuso, E..Fil: García, J..Fil: Rivulgo, M..Fil: Confalonieri, A..Fil: Sparo, M..Fil: Sánchez Bruni, S.

    E-Commerce, social media and Social Inclusion: A Typology of Users Over 60 Years of Age in Spain

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    The growth of e-commerce and the ageing of the world population converges in a situation which represents significant challenges for the economy: a large population of over 65year-olds with major limitations for online shopping. The digital division, although reduced in certain sectors, in others, such as e-commerce persists. This research involves the study of 405 subjects, Spanish seniors aged between 60 and 79, to discover and analyse the barriers, motivators and behaviour with regards to shopping online. Using a telephone survey and a random sample, a typology of users was established as per their behaviour and perception of e-commerce. The main finding is the segmentation in eleven typologies of users, identified through cluster analysis. The major conclusions confirm the barriers related to data security or levels of confidence. Furthermore, with basic digital skills, seniors consider themselves capable of completing purchases on the Internet. Online shoppers feel empowered being digitally self-sufficient, while non-shoppers desiring to be independent, require the implementation of measures to aid the process on commercial websites.El crecimiento del comercio electrónico y el envejecimiento de la población mundial convergen en una situación que representa importantes retos para la economía: una gran población de mayores de 65 años con grandes limitaciones para realizar compras en línea. La brecha digital, aunque se ha reducido en algunos sectores, en otros, como el del comercio electrónico, persiste. Esta investigación consiste en un estudio de 405 sujetos, españoles de entre 60 y 79 años, para conocer y analizar las barreras, las motivaciones y el comportamiento ante las compras online. Mediante una encuesta telefónica y con una muestra aleatoria, se estableció una tipología de usuarios según su comportamiento y percepción del comercio electrónico. El principal hallazgo es la segmentación en once tipologías de usuarios, identificadas a través del análisis de clúster. Las principales conclusiones confirman las barreras relacionadas con la seguridad de los datos o los niveles de confianza. Por otro lado, con unas habilidades digitales básicas, los mayores se consideran capaces de realizar compras en Internet. Los compradores online se sienten capacitados siendo autosuficientes digitalmente, mientras que los no compradores que desean ser independientes, requieren la implementación de medidas de ayuda al proceso en los sitios web comerciales

    Efectos de la variabilidad ambiental en la abundancia de especies marinas comerciales en el norte del golfo de California

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    Studies have shown that environmental variables significantly affect variation in stock abundance of marine populations. The northern Gulf of California (NGC) is a highly productive region of interest due to its fish resources and diversity. Conservation of the marine species inhabiting the region is of public interest. Our study analysed the influence of physical environmental factors on several commercial marine species, using catch per unit effort (CPUE) as a proxy for abundance. Generalized additive models were used to test the significance of selected environmental variables on stock abundance. Deseasonalized cross-correlation analysis was used to examine time-lagged correlations between CPUE and abiotic variables to identify response timings. The results suggest that for most commercial species the sea surface temperature and the long-term climate Pacific Decadal Oscillation index are the predominant predictors for species abundance, followed by the Colorado River discharge. The Multivariate ENSO Index and the Pacific-North American pattern indices also showed specific effects on certain species. The NGC is a highly dynamic region, where species respond to environmental changes according to the characteristics of their life histories.Diversas investigaciones han demostrado que las variables ambientales influyen significativamente en la variación en la abundancia de las poblaciones marinas. El norte del golfo de California (NGC) es una región altamente productiva de interés por sus recursos pesqueros y biodiversidad. La conservación de las especies marinas en la región es de interés público. Nuestro estudio analizó la influencia de los factores ambientales físicos sobre varias especies marinas comerciales, usando la captura por unidad de esfuerzo (CPUE) como proxy de la abundancia. Se usaron modelos de aditivos generalizados para probar que variables ambientales influyen significativamente sobre la abundancia del stock. Se utilizó un análisis de correlación cruzada desestacionalizado para examinar correlaciones con retraso entre la CPUE y las variables abióticas para identificar tiempos de respuesta. Los resultados sugieren que para la mayoría de las especies comerciales, la temperatura superficial del mar y el índice de la Oscilación Decadal del Pacífico son los predictores predominantes de la abundancia de especies, seguidos de la descarga del río Colorado. El índice multivariado ENOS y el índice del Patrón del Pacífico de América del Norte mostraron efectos en algunas especies. El NGC es una región altamente dinámica, donde las especies responden a los cambios ambientales de acuerdo con las características de sus historias de vida

    El teléfono móvil: disponibilidad, usos y relaciones por parte de los adolescentes entre 12 y 16 años

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    Presentamos los resultados de una investigación sobre el uso, la disponibilidad y algunos aspectos relativos a las relaciones que se establecen con diferentes personas en torno al teléfono móvil en una muestra de adolescentes (N=1211) entre 12 y 16 años de la provincia de Girona. Los resultados ponen de manifiesto la existencia de diferencias de género en cuanto a su disposición y uso, siendo las chicas las que en mayor porcentaje poseen un móvil y más horas dedican a usarlo. Los adolescentes prefieren hablar sobre lo que hacen con el móvil con los iguales, seguido de los hermanos o las hermanas y, en último lugar, con los adultos (progenitores y profesores o profesoras). Finalmente, se analiza cómo los adolescentes se muestran más interesados por e informados sobre Internet y el móvil en comparación con los otros cuatro medios audiovisuales explorados (televisión, ordenador, juegos para ordenador y videojuegos)

    Production of two novel laccase isoforms by a thermotolerant strain of Pycnoporus sanguineus isolated from an oil-polluted tropical habitat

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    A thermotolerant and halotolerant strain of Pycnoporus sanguineus was isolated from an oil-polluted site in a tropical area located in Veracruz, Mexico. This strain was able to grow at 47ºC and in culture medium containing 500 mM NaCl. The strain was also tolerant to the presence of 30,000 ppm of crude Maya oil. A 68-kDa protein purified submerged cultures exhibited laccase activity towards 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), guaiacol, syringaldazine and o-dianisidine, for which it presented the highest affinity (Km = 43 µM). Two-dimensional gel electrophoresis analysis showed that, unusual for laccases, the enzyme has two active isoforms, with isoelectric points of 7.00 and 7.08. The purified enzyme showed high thermostability, retaining 40% of its original activity after 3 h at 60ºC. This property seems to correlate with a long “shelf-life”, given that at 40ºC enzyme activity was only gradually lost over a 5-day period incubation. Both, the fungus and its laccase aer likely to have high potential for biotechnological applications

    Cod 3M Projections: risk estimation and inputs

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    The last full assessment for the 3M Cod in the NAFO Scientific Council was carried out in June 2015, giving an advice for two years. Some problems concerning the NAFO 3M cod projections were identified during the 2015 Annual Meeting. Trying to solve these issues, a Workshop was organized by the EU in March 2017. An issue raised by the Fisheries Commission in 2015 is that the risk of exceeding Flim for some of the projection scenarios presented in the assessment was difficult to interpret in light of the overlap in credible intervals of the yields of the various options. To solve this issue, the authors developed a new projection method to perform the 3M cod projections and compute risk, projecting a single catch value instead of a distribution of catches. One of the problems raised by the Scientific Council is how to estimate the inputs to be used in the projections due to the rapid changes in the biology of this stock, especially from 2007. Normally the last three years mean is used as input for these parameters. The changes in the biological parameters cause problems in the projections results as the inputs used for the projected years usually are overestimated, leading to an overestimation of the SSB and the associated TAC for a given F. To solve this issue, the authors suggest using just the last year inputs in the projections. An attempt to add uncertainty in the last year inputs was made, examining the interannual changes observed in past years in the inputs and taking into consideration the correlation between them. The uncertainty and the risk in the results increases considerably and it was suggested to study deeply this method before its implementation. The authors conclude that caution should be exercised concerning the results of the projections for this stock. If uncertainty in the projection inputs is implemented, advice for more than one year will not be accurate due to the issues identified.Executive Agency for Small and Medium-sized Enterprises (EASME)Versión del edito

    NAFO Cod 3M Workshop Current Assessment and Projection Uncertainties

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    On behalf of the Specific Contract No. 03 (SC03) Support to a robust model assessment, benchmark and development of a management strategy evaluation for cod in NAFO Division 3M under the Framework Contract EASME/EMFF/2016/008 Provision of Scientific Advice for Fisheries beyond EU Waters, the NAFO 3M cod assessment Workshop was held at the Instituto Español de Oceanografia (IEO), Vigo-Beiramar, Spain, during 21st-23rd March 2017. With the inclusion of the following three new points the provisional agenda (ToRs for Task 1 of SC03) was approved (Annex 1): Presentation of the Specific Contract No. 03 (SC03) Support to a robust model assessment, benchmark and development of a management strategy evaluation for cod in NAFO Division 3M. Proposals to be submitted to the 2017 June NAFO Scientific Council (SC) meeting. Recommendations from this Workshop on matters that need to be deeper studied during the benchmark process.The Executive Agency for Small and Medium-sized Enterprises (EASME

    Tecnología ósea en la Depresión del Río Salado (provincia de Buenos Aires)

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    Hunter-gatherer-fishers inhabited the wetlands of the Río Salado Depression (Argentine Pampas) during the Late Holocene (ca. 2400 to 400 years BP); they manufactured pottery and developed different strategies of acquisition and manufacture of bones and teeth for use as tools. The economy of these societies was based mainly on exploiting small-sized species, such as coypu (a rodent), fishes, as well as continental and aquatic birds. Two species of deer were complementary resources. Twenty-five bones from the sites LG1 (n= 4) and LG5 (n= 21) that show indications of human manipulation were subjected to a techno-morphological analysis. The following parameters were considered: material, type of fracture, dimensions and presence/absence of marks; the effects of taphonomic agents and processes on bone surfaces are evaluated as well. Human modification on the bones of several taxa were identified: Aves (n= 4), Rallidae (n= 1), Mammalia (n= 2), Cervidae (n=4), Ozotoceros bezoarticus (n=8), Blastoceros dichotomus (n= 1), Rodentia (n= 1), Rodentia cf. Caviinae (n= 3) and Myocastor coypus (n= 1). On this basis, we characterized the Morphological Groups as, tubes, bevelled tools, points (channelled, semi-channeled, blunt-ended), and those tools not allocated to these groups, were designated as Undetermined. The potential function of these tools is discussed, we propose that bone technology was part of the integral use of faunal resources in the area.En el humedal de la Depresión del Río Salado –habitado durante el Holoceno tardío (entre 2400 y 400 años AP) por grupos de expertos alfareros– los recursos faunísticos más explotados fueron especies de porte menor como coipo, peces, aves terrestres y acuáticas. Los cérvidos fueron recursos complementarios. Estos grupos desarrollaron estrategias de aprovisionamiento y manufactura de huesos, además de incisivos de coipo, para utilizar como instrumentos. Se analizaron tecno-morfológicamente 25 piezas óseas provenientes de los sitios LG1 (n= 4) y LG5 (n= 21) con evidencias de formatización antrópica. Se tomaron los siguientes parámetros: elemento, tipo de fractura, dimensiones y presencia/ausencia de huellas; asimismo se registró la incidencia de agentes y procesos tafonómicos sobre los elementos. Se identificaron varios taxa: Aves (= 4), Rallidae (n= 1), Mammalia (n= 2), Cervidae (n= 4), Ozotoceros bezoarticus (n= 8), Blastoceros dichotomus (n=1), Rodentia (n= 1), Rodentia cf. Caviinae (n= 3) y Myocastor coypus (n= 1). Se definieron los Grupos Morfológicos: tubos, biseles, puntas (acanalada, semiacanalada, roma) y aquellos que no pudieron asignarse a los ya definidos, se indicaron como indeterminados. Se discuten posibles funciones y se propone que esta tecnología ósea es parte del uso integral de los recursos faunísticos del área
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