4,032 research outputs found

    Fruit Rot Caused by Phytophthora sp. in Cold-Stored Pears in the Valley of Rio Negro and Neuquén, Argentina

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    Pear fruit conservation for long periods is associated with postharvest fungal diseases. In Argentina, the most important and widespread diseases are caused by Penicillium spp. and Botrytis cinerea, followed by Alternaria sp. and Cladosporium sp. and Athelia epiphylla. The last one can be important depending on the fruit-lot. This study reports the presence of one Oomycete, as the cause of pear fruit rot in postharvest. In 2010, during the first months of conservation of ‘Williams’, ‘Packham’s Triumph’ and ‘Red Bartlet’ pears, in cold storage, in the eastern area of Alto Valle of Río Negro, fruit decay was recorded with losses between 5 and 20%, according to fruit-lot. Symptoms of decay were studied and its ethiology was determined using conventional and molecular methods. Fruit started showing circular, light to dark brown areas with irregular and diffuse margins that spread rapidly. The decayed area remained firm. The lesion diameter increased and it extended to pulp tissue to reach fruit core with a hyperbolic shape, different from the spherical shape caused by Penicillium spp. or Botrytis sp. The pathogen was isolated in V8 agar selective medium from pears with symptoms. By morphologic characteristics (colony and sporangia) of isolates, its association with clade 6 of Phytophthora was determined. The identification of isolates was confirmed by direct sequencing of the ITS rDNA region using DC6 and ITS4 primers. The nucleotide sequence showed 100% of similarity (745/745 pb) with sequences available in GenBank and was identified as an undescribed species inside P. gonapodyides- P. megasperma Clade 6. This is the first report of a new Phytophthora in postharvest pears.La conservación del fruto de pera por períodos prolongados se asocia con enfermedades fúngicas poscosecha. En Argentina las enfermedades más importantes y extendidas son causadas por Penicillium spp. y Botrytis cinerea , seguida de Alternaria sp. y Cladosporium sp. y Athelia epiphylla . Este último puede ser importante dependiendo del lote de fruta. Este estudio reporta la presencia de un Oomiceto, como causante de la pudrición del fruto de pera en poscosecha. En 2010, durante los primeros meses de conservación de peras 'Williams', 'Packham's Triumph' y 'Red Bartlet', en cámaras frigoríficas, en la zona oriental del Alto Valle de Río Negro, se registró pudrición de frutos con pérdidas entre 5 y 20 %, según lote de fruto. Se estudiaron los síntomas de la descomposición y se determinó su etiología mediante métodos convencionales y moleculares. Los frutos comenzaron a mostrar áreas circulares, de color marrón claro a oscuro, con márgenes irregulares y difusos que se extendieron rápidamente. La zona deteriorada se mantuvo firme. El diámetro de la lesión aumentó y se extendió al tejido pulpar hasta llegar al corazón del fruto con forma hiperbólica, diferente a la forma esférica causada por Penicillium spp. o Botrytis sp. El patógeno se aisló en medio selectivo agar V8 de peras con síntomas. Por características morfológicas (colonia y esporangios) de los aislados se determinó su asociación con el clado 6 de Phytophthora . La identificación de los aislados se confirmó mediante secuenciación directa de la región ITS rDNA utilizando cebadores DC6 e ITS4. La secuencia de nucleótidos mostró 100% de similitud (745/745 pb) con secuencias disponibles en GenBank y fue identificada como una especie no descrita dentro de P. gonapodyides - P. megasperma Clado 6. Este es el primer reporte de una nueva Phytophthora en peras poscosecha.Fil: Dobra, Alicia Cristina. Universidad Nacional del Comahue. Facultad de Ciencias Agrarias; Argentina.Fil: Sosa, María Cristina. Universidad Nacional del Comahue. Facultad de Ciencias Agrarias; Argentina.Fil: Lutz, María Cecilia. Universidad Nacional del Comahue. Facultad de Ciencias Agrarias; Argentina.Fil: Rodriguez, Gustavo. Universidad Nacional del Comahue. Facultad de Ciencias Agrarias; Argentina

    A low-mass planet candidate orbiting Proxima Centauri at a distance of 1.5 AU

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    Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).Our nearest neighbor, Proxima Centauri, hosts a temperate terrestrial planet. We detected in radial velocities evidence of a possible second planet with minimum mass m c sin i c = 5.8 ± 1.9 M ⊕ and orbital period P c = 5.21 - 0.22 + 0.26 years. The analysis of photometric data and spectro-scopic activity diagnostics does not explain the signal in terms of a stellar activity cycle, but follow-up is required in the coming years for confirming its planetary origin. We show that the existence of the planet can be ascertained, and its true mass can be determined with high accuracy, by combining Gaia astrometry and radial velocities. Proxima c could become a prime target for follow-up and characterization with next-generation direct imaging instrumentation due to the large maximum angular separation of ~1 arc second from the parent star. The candidate planet represents a challenge for the models of super-Earth formation and evolution.Peer reviewedFinal Published versio

    Enose lab made with vacuum sampling: quantitative applications

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    A lab-made electronic nose (Enose) with vacuum sampling and a sensor array, comprising nine metal oxide semiconductor Figaro gas sensors, was tested for the quantitative analysis of vapor–liquid equilibrium, described by Henry’s law, of aqueous solutions of organic compounds: three alcohols (i.e., methanol, ethanol, and propanol) or three chemical compounds with different functional groups (i.e., acetaldehyde, ethanol, and ethyl acetate). These solutions followed a fractional factorial design to guarantee orthogonal concentrations. Acceptable predictive ridge regression models were obtained for training, with RSEs lower than 7.9, R2 values greater than 0.95, slopes varying between 0.84 and 1.00, and intercept values close to the theoretical value of zero. Similar results were obtained for the test data set: RSEs lower than 8.0, R2 values greater than 0.96, slopes varying between 0.72 and 1.10, and some intercepts equal to the theoretical value of zero. In addition, the total mass of the organic compounds of each aqueous solution could be predicted, pointing out that the sensors measured mainly the global contents of the vapor phases. The satisfactory quantitative results allowed to conclude that the Enose could be a useful tool for the analysis of volatiles from aqueous solutions containing organic compounds for which Henry’s law is applicable.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FED-ER under Programme PT2020 for financial support by national funds FCT/MCTES to CIMO (UID/AGR/00690/2019) and SusTEC (LA/P/0007/2020)info:eu-repo/semantics/publishedVersio

    Femtosecond two-photon absorption spectroscopy of poly(fluorene) derivatives containing benzoselenadiazole and benzothiadiazole

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    We have investigated the molecular structure and two-photon absorption (2PA) properties relationship of two push-pull poly(fluorene) derivatives containing benzoselenadiazole and benzothiadiazole units. For that, we have used the femtosecond wavelength-tunable Z-scan technique with a low repetition rate (1 kHz) and an energy per pulse on the order of nJ. Our results show that both 2PA spectra present a strong 2PA (around 600 GM (1 GM = 1×10-50 cm4 .s. photon-1)) band at around 720 nm (transition energy 3.45 eV) ascribed to the strongly 2PA-allowed 1Ag-like → mAg-like transition, characteristic of poly(fluorene) derivatives. Another 2PA band related to the intramolecular charge transfer was also observed at around 900 nm (transition energy 2.75 eV). In both 2PA bands, we found higher 2PA cross-section values for the poly(fluorene) containing benzothiadiazole unit. This outcome was explained through the higher charge redistribution at the excited state caused by the benzothiadiazole group as compared to the benzoselenadiazole and confirmed by means of solvatochromic Stokes shift measurements. To shed more light on these results, we employed the sum-over-states approach within the two-energy level model to estimate the maximum permanent dipole moment change related to the intramolecular charge transfer transition

    Resting energy expenditure is not altered in children and adolescents with obesity. Effect of age and gender and association with serum Leptin levels

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    In children and adolescents, obesity does not seem to depend on a reduction of resting energy expenditure (REE). Moreover, in this young population, the interactions between either age and obesity or between age and gender, or the role of leptin on REE are not clearly understood. To compare the levels of REE in children and adolescents we studied 181 Caucasian individuals (62% girls) classified on the basis of age-and sex-specific body mass index (BMI) percentile as healthy weight (n = 50), with overweight (n = 34), or with obesity (n = 97) and in different age groups: 8–10 (n = 38), 11–13 (n = 50), and 14–17 years (n = 93). REE was measured by indirect calorimetry and body composition by air displacement plethysmography. Statistically significant differences in REE/fat-free mass (FFM) regarding obesity or gender were not observed. Absolute REE increases with age (p < 0.001), but REE/FFM decreases (p < 0.001) and there is an interaction between gender and age (p < 0.001) on absolute REE showing that the age-related increase is more marked in boys than in girls, in line with a higher FFM. Interestingly, the effect of obesity on absolute REE is not observed in the 8–10 year-old group, in which serum leptin concentrations correlate with the REE/FFM (r = 0.48; p = 0.011). In conclusion, REE/FFM is not affected by obesity or gender, while the effect of age on absolute REE is gender-dependent and leptin may influence the REE/FFM in 8–10 year-olds

    Transfer of extracellular vesicle-microRNA controls germinal center reaction and antibody production

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    Intercellular communication orchestrates effective immune responses against disease-causing agents. Extracellular vesicles (EVs) are potent mediators of cell-cell communication. EVs carry bioactive molecules, including microRNAs, which modulate gene expression and function in the recipient cell. Here, we show that formation of cognate primary T-B lymphocyte immune contacts promotes transfer of a very restricted set of T-cell EV-microRNAs (mmu-miR20-a-5p, mmu-miR-25-3p, and mmu-miR-155-3p) to the B cell. Transferred EV-microRNAs target key genes that control B-cell function, including pro-apoptotic BIM and the cell cycle regulator PTEN. EV-microRNAs transferred during T-B cognate interactions also promote survival, proliferation, and antibody class switching. Using mouse chimeras with Rab27KO EV-deficient T cells, we demonstrate that the transfer of small EVs is required for germinal center reaction and antibody production in vivo, revealing a mechanism that controls B-cell responses via the transfer of EV-microRNAs of T-cell origin. These findings also provide mechanistic insight into the Griscelli syndrome, associated with a mutation in the Rab27a gene, and might explain antibody defects observed in this pathogenesis and other immune-related and inflammatory disorders.This manuscript was funded by grants SAF2017-82886-R (FS-M) from the Spanish Ministry of Economy and Competitiveness; CAM (S2017/BMD-3671-INFLAMUNE-CM) from the Comunidad de Madrid (FS-M); CIBERCV (CB16/11/00272), BIOIMID PIE13/041 from the Instituto de Salud Carlos III and from the Fundación La MaratóTV3(grant122/C/2015). The current research has received funding from “la Caixa” Foundation under the project code HR17-00016. VGY is supported by the AECC foundation. A.R.R. is supported by CNIC funding. This project was funded by the Spanish Ministerio de Ciencia, Innovacion y Universidades SAF2016-75511-R, and La Caixa Health Research Program HR17-00247 grant to A.R.R. Grants from Ramón Areces Foundation “Ciencias de la Vida y de la Salud” (XIX Concurso-2018) and from Ayuda Fundación BBVA y Equipo de Investigación Científica (BIOMEDICINA-2018) (to FSM). The CNIC is supported by the Ministerio de Ciencia, Innovacion y Universidades and the Pro-CNIC Foundation, and is a Severo Ochoa Center of Excellence (SEV-2015-0505).S

    Waste paper and macroalgae co-digestion effect on methane production

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    The present study investigates the effect on methane production from waste paper when co-digested with macroalgal biomass. Both feedstocks were previously mechanically pretreated to reduce their particle size. The study was planned according two factors: the feedstock to inoculum (F/I) ratio and the waste paper to macroalgae (WP/MA) ratio. The F/I ratios checked were 0.2, 0.3 and 0.4 and the WP/MA ratios were 0:100, 25:75, 50:50, 75:25 and 100:0. The highest methane yield (386 L kg−1 VSadded) was achieved at an F/I ratio of 0.2 and a WP/MA ratio of 50:50. A biodegradability index of 0.87 obtained in this study indicates complete conversion of feedstock at an optimum C/N ratio of 26. Synergistic effect was found for WP/MA 25:75, 50:50 and 75:25 mixing ratios compared with the substrates mono-digestion

    Clinical utility of one versus two faecal immunochemical test samples in the detection of advanced colorectal neoplasia in symptomatic patients

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    The utility of faecal immunochemical tests (FIT) in assessment of symptomatic patients with lower gastrointestinal symptoms has not been well explored. The aims of this study were to evaluate the diagnostic yield for advanced colorectal neoplasia (ACRN) in symptomatic patients using the first of two FIT samples (FIT/1) and the higher concentration of two FIT samples (FIT/max). METHODS: Samples from two consecutive bowel motions from 208 symptomatic patients who required colonoscopy were analysed using the HM-JACKarc analyser (Kyowa Medex Co., Ltd., Tokyo, Japan). Patients were categorised into two groups: patients with any ACRN and individuals with other diagnoses or normal colonoscopy. RESULTS: Colonoscopy detected ACRN in 29 patients. In these patients, FIT/1 and FIT/max were significantly higher than in patients with low-risk adenoma (p=0.006 and p=0.024), other findings (p=0.002 and p=0.002) and normal colonoscopy (p<0.001 and p<0.001). The areas under the curves (AUC) of FIT/1 and FIT/max were 0.71 and 0.69, respectively. Undetectable FIT/1 rules out 96.6% of ACRN and the specificity was 10.6%. Increasing the FIT/1 cut-off to 10 μg Hb/g faeces, sensitivity and specificity were 34.5% and 87.2%, respectively. Similar results were obtained using FIT/max with 20 μg Hb/g faeces cut-off, providing a sensitivity and specificity of 34.5% and 85.6%, respectively. CONCLUSIONS: Undetectable FIT is a good strategy to rule-out ACRN in symptomatic patients. The diagnostic yield of collecting two samples for FIT can be achieved with one sample, but a lower faecal haemoglobin concentrations (f-Hb) cut-off is required

    Effectiveness of Exercise on Fatigue and Sleep Quality in Fibromyalgia: A Systematic Review and Meta-analysis of Randomized Trials

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    Objectives: To determine the effects of exercise on fatigue and sleep quality in fibromyalgia (primary aim) and to identify which type of exercise is the most effective in achieving these outcomes (secondary aim). Data Sources: PubMed and Web of Science were searched from inception until October 18, 2018. Study Selection: Eligible studies contained information on population (fibromyalgia), intervention (exercise), and outcomes (fatigue or sleep). Randomized controlled trials (RCT) testing the effectiveness of exercise compared with usual care and randomized trials (RT) comparing the effectiveness of 2 different exercise interventions were included for the primary and secondary aims of the present review, respectively. Two independent researchers performed the search, screening, and final eligibility of the articles. Of 696 studies identified, 17 RCTs (nZ1003) were included for fatigue and 12 RCTs (nZ731) for sleep. Furthermore, 21 RTs compared the effectiveness of different exercise interventions (nZ1254). Data Extraction: Two independent researchers extracted the key information from each eligible study. Data Synthesis: Separate random-effect meta-analyses were performed to examine the effects from RCTs and from RTs (primary and secondary aims). Standardized mean differences (SMD) effect sizes were calculated using Hedges’ adjusted g. Effect sizes of 0.2, 0.4, and 0.8 were considered small, moderate, and large. Compared with usual care, exercise had moderate effects on fatigue and a small effect on sleep quality (SMD, e0.47; 95% confidence interval [CI], e0.67 to e0.27; P<.001 and SMD, e0.17; 95% CI, e0.32 to e0.01; PZ.04). RTs in which fatigue was the primary outcome were the most beneficial for lowering fatigue. Additionally, meditative exercise programs were the most effective for improving sleep quality. Conclusions: Exercise is moderately effective for lowering fatigue and has small effects on enhancing sleep quality in fibromyalgia. Meditative exercise programs may be considered for improving sleep quality in fibromyalgi
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