2,764 research outputs found

    Egg yolk IgY antibodies: A therapeutic intervention against group A rotavirus in calves

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    Bovine group A rotavirus (RVA) is considered the major cause of diarrhea in intensively reared neonatal calves. Chicken egg yolk antibodies (IgY) are efficient in protecting neonatal calves from RVA diarrhea; however, the value of this intervention in calves once diarrhea has appeared is unclear. The aim of the present study was to evaluate the application of RVA-specific IgY as a passive treatment in those cases. The experimental groups were: G1 = RVA-specific IgY treatment; G2 = no Ab treatment; and G3 = colostrum deprived + no Ab treatment. IgY treatment significantly reduced virus shedding, diarrhea duration and severity compared to G2 and G3 calves. However, it caused a partial suppression of systemic Ab responses to RVA that could be associated with less severe diarrhea. The oral treatment with IgY for 7 days was associated with significantly higher antibody secreting cell responses in the calves compared with other groups of animals.Fil: Vega, Celina Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; ArgentinaFil: Bok, Marina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; ArgentinaFil: Saif, L.. Ohio State University; Estados UnidosFil: Fernandez, F.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; ArgentinaFil: Parreño, Gladys Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentin

    Ectomycorrhizal status of a mature productive black truffle plantation

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    The truffle-plantation «Los Quejigares» was planted in 1971 by AROTZ-CATESA company. It is a 600 ha plot of Quercus ilexmycorrhizated with Tuber melanosporum at 1,250 m a.s.l. on calcareous soil. This plantation is the largest of the world and one of the eldest truffle-plantations of Spain and it is in full production. Knowledge of the mycorrhizal status of a mature black truffle plantation is significant for the improvement of truffle cultivation. Ectomycorrhizae were studied for knowing T. melanosporum persistence and diversity and abundance of other ectomycorrhizal types. Roots of 16 holmoaks were sampled, 12 trees produce truffle sporocarps and four did not. It was found a mean of about 35% of T. melanosporum ectomycorrhizae in the studied trees, being this significantly higher in the productive trees. Also, 105 more different ectomycorrhizal types were found. In spite of the high number of morphotypes found, it seems that they do not replace T. melanosporum, showing that there is a coexistence between species in the fungal community associated to the roots

    Caracterización de ectomicorrizas en encinares productores de trufa negra del noreste de Soria

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    Black truffle sporocarp production is determined, amongst many other factors, by an optimum mycorrhization degree in the roots of the host-tree. This process is triggered in balance with other fungal species that does not inhibit its sporocarp production. So, there is an ectomycorrhizal fungal community associated with the black truffle sporocarp productive host-trees that runs as any other living beings community, producing a certain fungal biodiversity and establishing connections in dynamic balance that will evolve. The absence of black truffle sporocarps production in some host-trees will be determined by its ectomycorrhiza absence, or because between the fungal community there are one or more species that inhibit this process or displace it. With the aim of study those topics, the ectomycorrhizae present in 23 adult holmoak trees (Quercus ilex subsp. ballota (Desf.) Samp.) of seven Tuber melanosporum Vittad. productive areas in the North-West of Soria (inner Spain) are characterized and quantified. During the spring and the autumn of 1999 and 2000, black truffle productive and non-productive holmoaks were studied following the global method (Verlhac et al., 1990, La truffe guide pratique). Ectomycorrhizal types were characterized following the guidelines of Agerer (1999). Tuber melanosporum, T. aestivum Vittad., T. brumale Vittad., Cenococcum geophylum Fr., Pisolithus arrhizus (Scop.) Rauscher, Cantharellus tubaeformis (Bull.) Fr., Hebeloma cf. sinapizans (Fr.) Sacc., Tomentella galzinii Bourdot, AD type, Cortinarius sp., Hebeloma sp. and Scleroderma sp. and many others Telephorales, Tuberales and Boletales ectomycorrhizal types were found. Tuber melanosporum mycorrhizae are present both in productive and non-productive hosttrees, as it happens for T. aestivum, while T. brumale ectomycorrhizae are only present in nonproductive holmoaks. The rest of identified ectomycorrhizal types are present in productive and non-productive host-trees

    Millimagnitude Photometry for Transiting Extrasolar Planetary Candidates IV: The Puzzle of the Extremely Red OGLE-TR-82 Primary Solved

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    We present precise new V, I, and K-band photometry for the planetary transit candidate star OGLE-TR-82. Good seeing V-band images acquired with VIMOS instrument at ESO VLT allowed us to measure V=20.6+-0.03 mag star in spite of the presence of a brighter neighbour about 1" away. This faint magnitude answers the question why it has not been possible to measure radial velocities for this object. One transit of this star has been observed with GMOS-S instrument of GEMINI-South telescope in i and g-bands. The measurement of the transit allows us to verify that this is not a false positive, to confirm the transit amplitude measured by OGLE, and to improve the ephemeris. The transit is well defined in i-band light curve, with a depth of A_i=0.034 mag. It is however, less well defined, but deeper (A_g=0.1 mag) in the g-band, in which the star is significantly fainter. The near-infrared photometry obtained with SofI array at the ESO-NTT yields K=12.2+-0.1 and V-K=8.4+-0.1, so red that it is unlike any other transit candidate studied before. Due to the extreme nature of this object, we have not yet been able to measure velocities for this star, but based on the new data we consider two different possible configurations:(1) a nearby M7V star, or (2) a blend with a very reddened distant red giant. The nearby M7V dwarf hypothesis would give a radius for the companion of R_p=0.3+-0.1 R_J, i.e. the size of Neptune. Quantitative analysis of near-IR spectroscopy finally shows that OGLE-TR-82 is a distant, reddened metal poor early K giant. This result is confirmed by direct comparison with stellar templates that gives the best match for a K3III star. Therefore, we discard the planetary nature of the companion. Based on all the new data, we conclude that this system is a main-sequence binary blended with a background red giant.Comment: 26 pages, 9 figures, ApJ accepte

    Regulation of RUVBL1-RUVBL2 AAA-ATPases by the nonsense-mediated mRNA decay factor DHX34, as evidenced by Cryo-EM

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    Nonsense-mediated mRNA decay (NMD) is a surveillance pathway that degrades aberrant mRNAs and also regulates the expression of a wide range of physiological transcripts. RUVBL1 and RUVBL2 AAA-ATPases form an hetero-hexameric ring that is part of several macromolecular complexes such as INO80, SWR1, and R2TP. Interestingly, RUVBL1-RUVBL2 ATPase activity is required for NMD activation by an unknown mechanism. Here, we show that DHX34, an RNA helicase regulating NMD initiation, directly interacts with RUVBL1-RUVBL2 in vitro and in cells. Cryo-EM reveals that DHX34 induces extensive changes in the N-termini of every RUVBL2 subunit in the complex, stabilizing a conformation that does not bind nucleotide and thereby down-regulates ATP hydrolysis of the complex. Using ATPase-deficient mutants, we find that DHX34 acts exclusively on the RUVBL2 subunits. We propose a model, where DHX34 acts to couple RUVBL1-RUVBL2 ATPase activity to the assembly of factors required to initiate the NMD response.Spanish Ministry of Science and Innovation SAF2017-82632-P Andres Lopez-Perrote Carlos F Rodriguez Marina Serna Oscar Llorca. Autonomous Government of Madrid Y2018/BIO4747 Ana Gonzalez-Corpas Oscar Llorca. Autonomous Government of Madrid P2018/NMT4443 Ana Gonzalez-Corpas Oscar Llorca MRC Core funding Javier F Caceres Spanish Ministry of Science and Innovation BES-2015-071348 Carlos F Rodriguez The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.S

    Síntesis de ectomicorrizas entre Cistus sp. y las especies del complejo Boletus edulis

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    En los jarales resultantes de la reiteración de incendios forestales en el oeste de Castilla y León (León, Salamanca y Zamora) es habitual la presencia de fructificaciones de Boletus edulis Bull. La recolección de estos hongos micorrícicos comestibles en los jarales dominados exclusivamente por Cistus ladanifer, supone una oportunidad económica alternativa a los usos tradicionales para zonas con bajos ingresos procedentes del monte. El objetivo de éste trabajo es la obtención de ectomicorrizas de las especies del complejo B. edulis con Cistus sp. bajo condiciones controladas, y las descripciones anatómicas detalladas de las mismas. La identificación de los aislados fúngicos de Boletus aereus Bull., B. edulis, B. reticulatus Schaeff. y B. pinophilus Pilát & Dermek fue confirmada por métodos moleculares. Se han obtenido ectomicorrizas de Boletus aereus, B. edulis y B. reticulatus con Cistus albidus L. y C. ladanifer en condiciones de síntesis en cultivo puro, en un substrato de turbavermiculita estéril y solución nutritiva. Las ectomicorrizas formadas se describieron siguiendo los caracteres anatómicos y morfológicos habituales. Las tres ectomicorrizas son muy similares, de color blanco, con ramificación monopodial-pinnada, manto formado por tres capas plectenquimatosas y con rizomorfos de tipo boletoide

    ENE-COVID nationwide serosurvey served to characterize asymptomatic infections and to develop a symptom-based risk score to predict COVID-19

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    Objectives: To characterize asymptomatic SARS-CoV-2 infections and develop a symptom-based risk score useful in primary healthcare. Study design and setting: Sixty-one thousand ninty-two community-dwelling participants in a nationwide population-based serosurvey completed a questionnaire on COVID-19 symptoms and received an immunoassay for SARS-CoV-2 IgG antibodies between April 27 and June 22, 2020. Standardized prevalence ratios for asymptomatic infection were estimated across participant characteristics. We constructed a symptom-based risk score and evaluated its ability to predict SARS-CoV-2 infection. Results: Of all, 28.7% of infections were asymptomatic (95% CI 26.1-31.4%). Standardized asymptomatic prevalence ratios were 1.19 (1.02-1.40) for men vs. women, 1.82 (1.33-2.50) and 1.45 (0.96-2.18) for individuals <20 and ≥80 years vs. those aged 40-59, 1.27 (1.03-1.55) for smokers vs. nonsmokers, and 1.91 (1.59-2.29) for individuals without vs. with case contact. In symptomatic population, a symptom-based score (weights: severe tiredness = 1; absence of sore throat = 1; fever = 2; anosmia/ageusia = 5) reached standardized seroprevalence ratio of 8.71 (7.37-10.3), discrimination index of 0.79 (0.77-0.81), and sensitivity and specificity of 71.4% (68.1-74.4%) and 74.2% (73.1-75.2%) for a score ≥3. Conclusion: The presence of anosmia/ageusia, fever with severe tiredness, or fever without sore throat should serve to suspect COVID-19 in areas with active viral circulation. The proportion of asymptomatics in children and adolescents challenges infection control.The ENE-COVID study was supported by the Spanish Ministry of Health, the Institute of Health Carlos III, and the Spanish National Health System. The funders were in- volved in the study logistics, but they had no role in study design or in the collection, analysis, interpretation of data, or the decision to submit the article for publicationS

    Semaphorin 4B is an ADAM17-cleaved adipokine that inhibits adipocyte differentiation and thermogenesis

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    Objective: The metalloprotease ADAM17 (also called TACE) plays fundamental roles in homeostasis by shedding key signaling molecules from the cell surface. Although its importance for the immune system and epithelial tissues is well-documented, little is known about the role of ADAM17 in metabolic homeostasis. The purpose of this study was to determine the impact of ADAM17 expression, specifically in adipose tissues, on metabolic homeostasis.Methods: We used histopathology, molecular, proteomic, transcriptomic, in vivo integrative physiological and ex vivo biochemical approaches to determine the impact of adipose tissue-specific deletion of ADAM17 upon adipocyte and whole organism metabolic physiology.Results: ADAM17adipoq-creD/D mice exhibited a hypermetabolic phenotype characterized by elevated energy consumption and increased levels of adipocyte thermogenic gene expression. On a high fat diet, these mice were more thermogenic, while exhibiting elevated expression levels of genes associated with lipid oxidation and lipolysis. This hypermetabolic phenotype protected mutant mice from obesogenic challenge, limiting weight gain, hepatosteatosis and insulin resistance. Activation of beta-adrenoceptors by the neurotransmitter norepinephrine, a key regulator of adipocyte physiology, triggered the shedding of ADAM17 substrates, and regulated ADAM17 expression at the mRNA and protein levels, hence identifying a functional connection between thermogenic licensing and the regulation of ADAM17. Proteomic studies identified Semaphorin 4B (SEMA4B), as a novel ADAM17-shed adipokine, whose expression is regulated by physiological thermogenic cues, that acts to inhibit adipocyte differentiation and dampen thermogenic responses in adipocytes. Transcriptomic data showed that cleaved SEMA4B acts in an autocrine manner in brown adipocytes to repress the expression of genes involved in adipogenesis, thermogenesis, and lipid uptake, storage and catabolism.Conclusions: Our findings identify a novel ADAM17-dependent axis, regulated by beta-adrenoceptors and mediated by the ADAM17-cleaved form of SEMA4B, that modulates energy balance in adipocytes by inhibiting adipocyte differentiation, thermogenesis and lipid catabolism.(c) 2023 The Authors. Published by Elsevier GmbH. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
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