528 research outputs found

    Interaction of maternal photoperiod history and food type on growth and reproductive development of laboratory meadow voles (Microtus pennsylvanicus)

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    The interaction of maternal photoperiod history and four diets were tested by measuring body growth, reproductive development, and pelage development in 9-week-old juvenile meadow voles. Meadow vole dams were housed in long daylengths (LD; 14 h light/day), short daylengths for 2 weeks (SD; 10 h light/day), or short daylengths for 26 weeks (PR; photorefractory) prior to mating. Immediately following parturition, one of four diets was available to dams and pups; (a) a control diet containing no 6-methoxy-2-benzoxazolinone (6-MBOA); (b) the control diet plus sprouted wheat (which contains 6-MBOA); (c) the control diet plus alfalfa harvested in spring (no 6-MBOA); and (d) the control diet plus alfalfa harvested in autumn (no 6-MBOA). By 9 weeks of age, juvenile meadow voles born to photorefractory dams and fed either spring or fall alfalfa or sprouted wheat were significantly larger and more had achieved puberty than juveniles fed only the control diet. Juveniles born to LD dams demonstrated a smaller increase in developmental rate than photorefractory juveniles when fed alfalfa and spring wheat, and juveniles of SD dams showed the smallest effect of alfalfa and sprouted wheat on development. Supplements of spring wheat and both forms of alfalfa had similar positive effects on growth and reproduction. The authors suggest that juvenile meadow voles rely on the interaction of maternal photoperiod history and the availability of nutrient-rich food such as sprouted wheat and alfalfa to time the onset of growth and puberty.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/60640/1/interaction_of_maternal.pd

    Effects of particle size on CO2 reduction and discharge characteristics in a packed bed plasma reactor

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    Current understanding of the behaviour of plasma discharges within packed bed reactors (PBRs) is very poor, and the effects of many of the parameters that can be varied are still unknown. This article investigates the effects of particle size (180 μm to 2000 μm) of two different commonly used packing materials (Al2O3 and BaTiO3) on the conversion of CO2 in PBRs. The reactor behaviour is observed through determination of product gas composition and plasma power consumption in order to determine CO2 conversion and reactor efficiency. Electrical characterisation techniques are used to determine reactor burning voltage, and capacitances. These capacitances are subsequently used to quantify the occurrence of reactor partial discharging over a range of different operating conditions. The results indicate that smaller particles (down to 180 μm) can significantly increase CO2 conversion by up to 70%, provided that the voltage applied is sufficiently high to generate a discharge in the void spaces of the packing material. However, with decreasing particle size, the reactor burning voltage is found to increase rapidly, as well as the tendency of the reactor towards partial discharging

    Correction to: Tumour suppressor EP300, a modulator of paclitaxel resistance and stemness, is downregulated in metaplastic breast cancer

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    In the original publication, Fig. 1 depicting the blot for EP300 in CAL51 cells (Fig. 1c) was unintentionally duplicated with that from MDA-MB-231 cells (Fig. 1d). The new figure given in this erratum depicts the correct EP300 blot in Fig. 1c

    Caracterização e ocorrência do distúrbio do amolecimento precoce em mamões 'Golden'

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    The occurrence of green skin and soft pulp in 'Golden' papaya fruit during certain seasons has been reported by farmers in the northern of the state of Espirito Santo, Brazil. The objective of this study was to characterize and determine the occurrence of this disorder, which was referred as "early softening disorder". Fruits were harvested weekly for 11 months (from September to July). The fruits were stored at 10°C, and then fruit flesh firmness and skin color were analyzed. The results of the firmness test were submitted to regression analysis assuming a linear trendline. The slope of the curve was called the 'softening index' (SI). Fruits with early softening are characterized by a loss of firmness in less than 10 days, even when stored under refrigeration. Although softened, the skin of the fruit remains partially green. Fruits with the disorder occurred more frequently from mid-summer to mid-autumn (February to May). It is not possible to distinguish early softening disorder fruits from those without the disorder by skin color and flesh firmness analysis at the time of the harvest.Tem sido relatado por produtores da região norte do Espírito Santo a ocorrência de mamões 'Golden' com casca verde e polpa mole, em determinadas épocas do ano. O objetivo deste trabalho foi caracterizar e determinar a ocorrência deste distúrbio denominado de amolecimento precoce. Foram realizadas coletas semanais durante 11 meses (período de setembro a julho). Os frutos foram armazenados a 10°C e analisados quanto à firmeza da polpa e à cor da casca. Os resultados de firmeza da polpa foram submetidos à análise de regressão, assumindo-se que a equação é do tipo linear, e o ângulo de inclinação da curva foi chamado Índice de Amolecimento (IA). Frutos com o distúrbio caracterizaram-se pela perda da firmeza em menos de 10 dias, mesmo quando armazenados sob refrigeração. Embora amolecidos, a coloração da casca manteve-se parcialmente verde. A maior frequência de frutos com o distúrbio ocorreu de meados de verão a meados de outono (fevereiro a maio). Não é possível distinguir frutos com o distúrbio do amolecimento precoce daqueles normais pela análise da cor da casca e da firmeza da polpa, no momento da colheita

    Maximum rates of N2 fixation and primary production are out of phase in a developing cyanobacterial bloom in the Baltic Sea

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    Although N2-fixing cyanobacteria contribute significantly to oceanic sequestration of atmospheric CO2, little is known about how N2 fixation and carbon fixation (primary production) interact in natural populations of marine cyanobacteria. In a developing cyanobacterial bloom in the Baltic Sea, rates of N2 fixation (acetylene reduction) showed both diurnal and longer-term fluctuations. The latter reflected fluctuations in the nitrogen status of the cyanobacterial population and could be correlated with variations in the ratio of acetylene reduced to 15N2 assimilated. The value of this ratio may provide useful information about the release of newly fixed nitrogen by a cyanobacterial population. However, although the diurnal fluctuations in N2 fixation broadly paralleled diurnal fluctuations in carbon fixation, the longer-term fluctuations in these two processes were out of phase

    GEOTRACES IC1 (BATS) contamination-prone trace element isotopes Cd, Fe, Pb, Zn, Cu, and Mo intercalibration

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    International audienceWe report data on the isotopic composition of cadmium, copper, iron, lead, zinc, and molybdenum at the GEOTRACES IC1 BATS Atlantic intercalibration station. In general, the between lab and within-lab precisions are adequate to resolve global gradients and vertical gradients at this station for Cd, Fe, Pb, and Zn. Cd and Zn isotopes show clear variations in the upper water column and more subtle variations in the deep water; these variations are attributable, in part, to progressive mass fractionation of isotopes by Rayleigh distillation from biogenic uptake and/or adsorption. Fe isotope variability is attributed to heavier crustal dust and hydrothermal sources and light Fe from reducing sediments. Pb isotope variability results from temporal changes in anthropogenic source isotopic compositions and the relative contributions of U.S. and European Pb sources. Cu and Mo isotope variability is more subtle and close to analytical precision. Although the present situation is adequate for proceeding with GEOTRACES, it should be possible to improve the within-lab and between-lab precisions for some of these properties

    Effect of sirolimus on malignancy and survival after kidney transplantation: systematic review and meta-analysis of individual patient data

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    Objective To examine risk of malignancy and death in patients with kidney transplant who receive the immunosuppressive drug sirolimus.Design Systematic review and meta-analysis of individual patient data.Data sources Medline, Embase, and the Cochrane Central Register of Controlled Trials from inception to March 2013.Eligibility Randomized controlled trials comparing immunosuppressive regimens with and without sirolimus in recipients of kidney or combined pancreatic and renal transplant for which the author was willing to provide individual patient level data. Two reviewers independently screened titles/abstracts and full text reports of potentially eligible trials to identify studies for inclusion. All eligible trials reported data on malignancy or survival.Results the search yielded 2365 unique citations. Patient level data were available from 5876 patients from 21 randomized trials. Sirolimus was associated with a 40% reduction in the risk of malignancy (adjusted hazard ratio 0.60, 95% confidence interval 0.39 to 0.93) and a 56% reduction in the risk of non-melanoma skin cancer (0.44, 0.30 to 0.63) compared with controls. the most pronounced effect was seen in patients who converted to sirolimus from an established immunosuppressive regimen, resulting in a reduction in risk of malignancy (0.34, 0.28 to 0.41), non-melanoma skin cancer (0.32, 0.24 to 0.42), and other cancers (0.52, 0.38 to 0.69). Sirolimus was associated with an increased risk of death (1.43, 1.21 to 1.71) compared with controls.Conclusions Sirolimus was associated with a reduction in the risk of malignancy and non-melanoma skin cancer in transplant recipients. the benefit was most pronounced in patients who converted from an established immunosuppressive regimen to sirolimus. Given the risk of mortality, however, the use of this drug does not seem warranted for most patients with kidney transplant. Further research is needed to determine if different populations, such as those at high risk of cancer, might benefit from sirolimus.PfizerOttawa Hosp, Res Inst, Ottawa, ON K1H 7W9, CanadaUniv Ottawa, Ottawa, ON, CanadaCairo Univ, Cairo Kidney Ctr, Cairo, EgyptLimites Med Res, Vacallo, SwitzerlandUniv Manitoba, Dept Pediat & Childs Hlth, Winnipeg, MB, CanadaLund Univ, Dept Nephrol & Transplantat, Malmo, SwedenUniversidade Federal de São Paulo, Hosp Rim & Hipertensao, São Paulo, BrazilAddenbrookes Hosp, Dept Renal Med, Cambridge, EnglandNorthwestern Univ, Feinberg Sch Med, Chicago, IL 60611 USAMaastricht Univ, Med Ctr, Maastricht, NetherlandsSt Louis Hosp, Dept Nephrol, Paris, FranceHosp JW Goethe, Div Nephrol, Frankfurt, GermanyUniv Munich, Dept Surg, Munich, GermanyGoethe Univ Frankfurt, JW Goethe Clin, Clin Dermatol Venerol & Allergol, Frankfurt, GermanyInst Klin Expt Med, Dept Nephrol, Prague, Czech RepublicUniv Cambridge, Addenbrookes Hosp, Dept Surg, NIHR Cambridge Biomed Res Ctr, Cambridge CB2 2QQ, EnglandUniversidade Federal de São Paulo, Hosp Rim & Hipertensao, São Paulo, BrazilWeb of Scienc

    The relationship between seminal leukocytes, oxidative status in the ejaculate, and apoptotic markers in human spermatozoa

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    The aim of this study was to investigate the relationship between seminal leukocytes, reactive oxygen species (ROS) production in the ejaculate, and markers of apoptosis in human spermatozoa. Semen samples were collected from 60 patients attending fertility clinics at the Reproductive Biology Unit at Tygerberg Academic Hospital and Vincent Pallotti Hospital, Cape Town, South Africa. The concentration of seminal leukocytes was determined and was correlated with ROS production in the ejaculate, the percentage of superoxide (·O2 )- and hydrogen peroxide (H2O2)-positive spermatozoa, glutathione activation in the ejaculate, and with markers of apoptosis in spermatozoa, namely cysteine-dependent aspartate-directed proteases (caspase)-3/7 activation, mitochondrial membrane potential (ΔΨm), and the percentage of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL)-positive sperm. Significant correlations with the concentration of seminal leukocytes were found for ROS production in the ejaculate, the percentage of ·O2 -positive spermatozoa, and caspase-3/7 activation in the ejaculate. Leukocytospermic samples showed significantly higher ROS production, percentage of ·O2 -positive sperm, GSH activation, and caspase-3/7 activation compared to non-leukocytospermic samples. The percentage of ·O2 -positive sperm was significantly correlated with sperm ΔΨm and caspase-3/7 activation in the ejaculate. Sperm ΔΨm and TUNEL-positive sperm did not correlate with seminal leukocyte concentration. Data demonstrate that high seminal leukocyte concentrations that leads to increased seminal ROS production, and is also associated with caspase activation in the male germ cell and increased mitochondrial ROS production. The latter could possibly be a result of disturbed ΔΨm. The activation of caspase-3/7 could then follow the increased intrinsic superoxide levels due to depleted intrinsic glutathione (GSH). These cellular events might not directly and immediately lead to DNA fragmentation as an endpoint of apoptosis because of topological hindrances.Web of Scienc
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