773 research outputs found

    Effect of Co-Inoculation with Mycorrhiza and Rhizobia on the Nodule Trehalose Content of Different Bean Genotypes

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    Studies on Rhizobium-legume symbiosis show that trehalose content in nodules under drought stress correlates positively with an increase in plant tolerance to this stress. Fewer reports describe trehalose accumulation in mycorrhiza where, in contrast with rhizobia, there is no flux of carbohydrates from the microsymbiont to the plant. However, the trehalose dynamics in the Mycorrhiza-Rhizobium-Legume tripartite symbiosis is unknown. The present study explores the role of this tripartite symbiosis in the trehalose content of nodules grown under contrasting moisture conditions. Three wild genotypes (P. filiformis, P. acutifolis and P. vulgaris) and two commercial genotypes of Phaseolus vulgaris (Pinto villa and Flor de Mayo) were used. Co-inoculation treatments were conducted with Glomus intraradices and a mixture of seven native rhizobial strains, and trehalose content was determined by GC/MS. The results showed a negative effect of mycorrhizal inoculation on nodule development, as mycorrhized plants showed fewer nodules and lower nodule dry weight compared to plants inoculated only with Rhizobium. Mycorrhizal colonization was also higher in plants inoculated only with Glomus as compared to plants co-inoculated with both microsymbionts. In regard to trehalose, co-inoculation negatively affects its accumulation in the nodules of each genotype tested. However, the correlation analysis showed a significantly positive correlation between mycorrhizal colonization and nodule trehalose content

    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

    HPV-16 infection modifies overall survival of Puerto Rican HNSCC patients

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    International audienceThis paper presents a set of experimental results concerning the sliding mode control of an electro-pneumatic system. Two discrete-time control strategies are considered for the implementation of the discontinuous part of the sliding mode controller: explicit and implicit discretizations. While the explicit implementation is known to generate numerical chattering [6], [7], [12], [13], the implicit one is expected to significantly reduce chattering while keeping the accuracy. The experimental results reported in this work remarkably confirm that the implicit discrete-time sliding mode supersedes the explicit ones, with several important features: chattering in the control input is almost eliminated (while the explicit and saturated controllers behave like high-frequency bang-bang inputs), the input magnitude depends only on the perturbation size and is largely independent of the controller gain and sampling time

    A review of ureteral injuries after external trauma

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    <p>Abstract</p> <p>Introduction</p> <p>Ureteral trauma is rare, accounting for less than 1% of all urologic traumas. However, a missed ureteral injury can result in significant morbidity and mortality. The purpose of this article is to review the literature since 1961 with the primary objective to present the largest medical literature review, to date, regarding ureteral trauma. Several anatomic and physiologic considerations are paramount regarding ureteral injuries management.</p> <p>Literature review</p> <p>Eighty-one articles pertaining to traumatic ureteral injuries were reviewed. Data from these studies were compiled and analyzed. The majority of the study population was young males. The proximal ureter was the most frequently injured portion. Associated injuries were present in 90.4% of patients. Admission urinalysis demonstrated hematuria in only 44.4% patients. Intravenous ureterogram (IVU) failed to diagnose ureteral injuries either upon admission or in the operating room in 42.8% of cases. Ureteroureterostomy, with or without indwelling stent, was the surgical procedure of choice for both trauma surgeons and urologists (59%). Complications occurred in 36.2% of cases. The mortality rate was 17%.</p> <p>Conclusion</p> <p>The mechanism for ureteral injuries in adults is more commonly penetrating than blunt. The upper third of the ureter is more often injured than the middle and lower thirds. Associated injuries are frequently present. CT scan and retrograde pyelography accurately identify ureteral injuries when performed together. Ureteroureterostomy, with or without indwelling stent, is the surgical procedure of choice of both trauma surgeons and urologists alike. Delay in diagnosis is correlated with a poor prognosis.</p

    Metabolome and proteome changes in skeletal muscle and blood of pre-weaning calves fed leucine and threonine supplemented diets

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    In pre-weaning calves, both leucine and threonine play important roles in growth and muscle metabolism. In this study, metabolomics, proteomics and clinical chemistry were used to assess the effects of leucine and threonine supplementation added to milk replacer on 14 newborn Holstein male calves: 7 were fed a control diet (Ctrl) and 7 were fed the Ctrl diet supplemented with 0.3% leucine and 0.3% threonine (LT) from 5.6 days of age to 53.6 days. At this time, blood and semitendinosus muscle biopsies were collected for analysis. Integrated metabolomics and proteomics showed that branched-chain amino acids (BCAA) degradation and mitochondrial oxidative metabolism (citrate cycle and respiratory chain) were the main activated pathways in muscle because of the supplementation. BCAA derivatives and metabolites related to lipid mobilization showed the major changes. The deleterious effects of activated oxidative phosphorylation were balanced by the upregulation of antioxidant proteins. An increase in protein synthesis was indicated by elevated aminoacyl-tRNA biosynthesis and increased S6 ribosomal protein phosphorylation in skeletal muscle. In conclusion, LT group showed greater BCAA availability and mitochondrial oxidative activity; as the muscle cells undergo greater aerobic metabolism, antioxidant defenses were activated to compensate for possible cell damage. Data are available via ProteomeXchange (PXD016098)info:eu-repo/semantics/acceptedVersio

    EFECTIVIDAD DE TRICHODERMA HARZIANUM SOBRE LA POBLACIÓN DE NEMÁTODOS FITOPATÓGENOS EN CAFÉ (COFFEA ARÁBICA L.) EN CONDICIONES DE VIVERO EN EL MUNICIPIO JUNÍN, ESTADO TÁCHIRA. VENEZUELA

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    Con el objeto de determinar la cuantía en que se puede prescindir del control químico para manejar los nemátodos fitopatógenos en el cultivo del café, se realizó un estudio sobre la efectividad del Trichoderma harzianum como biocontrolador en base al estado fitosanitario del cultivo de café (coffea arábica, L.) en la fase de vivero, evaluándose la infestación causada por los nemátodos. La investigación se desarrolló en el municipio Junín, Estado Táchira. Se utilizaron plántulas en bolsas con sustrato de mezcla 2 partes de tierra, 1 de materia orgánica y 1 de arena, realizando aplicaciones con Trichoderma harzianum con tres concentraciones de conidias. Se utilizó un diseño de bifactorial con siete tratamientos y diez repeticiones T1: Plántula + testigo absoluto; T2: plántula + Trichoderma 1 x 109 ufc/ml; T3: plántula + Trichoderma de 1 x 1018ufc/ml. T-4:plántula + Trichoderma de 1 x 1027 ufc/ml; T-5:sustracto solo + Trichoderma de 1 x 109 ufc/ml; T-6:sustracto solo + Trichoderma de 1 x 1018ufc/ml;T-7:sustracto solo + Trichoderma de 1 x 1027ufc/ml. Se concluye que la aplicación con el tratamiento T7 = sustrato solo + Trichoderma de 1 x 1027ufc/ml. Erradico en un 100% los nemátodos de los géneros meloidogyne spp y pratylenchus spp , y en cuanto al desarrollo agroproductivo de las plántulas de café en la fase de vivero el tratamiento T-4:plántula + Trichoderma de 1 x 1027ufc/ml, es el que propicia el crecimiento, desarrollo de las plántulas y el control de los nemátodos fitopatógenos de forma adecuada

    Convergent evolution of conserved mitochondrial pathways underlies repeated adaptation to extreme environments

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    Extreme environments test the limits of life; yet, some organisms thrive in harsh conditions. Extremophile lineages inspire questions about how organisms can tolerate physiochemical stressors and whether the repeated colonization of extreme environments is facilitated by predictable and repeatable evolutionary innovations. We identified the mechanistic basis underlying convergent evolution of tolerance to hydrogen sulfide (H2S)-a toxicant that impairs mitochondrial function-across evolutionarily independent lineages of a fish (Poecilia mexicana, Poeciliidae) from H2S-rich springs. Using comparative biochemical and physiological analyses, we found that mitochondrial function is maintained in the presence of H2S in sulfide spring P. mexicana but not ancestral lineages from nonsulfidic habitats due to convergent adaptations in the primary toxicity target and a major detoxification enzyme. Genome-wide local ancestry analyses indicated that convergent evolution of increased H2S tolerance in different populations is likely caused by a combination of selection on standing genetic variation and de novo mutations. On a macroevolutionary scale, H2S tolerance in 10 independent lineages of sulfide spring fishes across multiple genera of Poeciliidae is correlated with the convergent modification and expression changes in genes associated with H2S toxicity and detoxification. Our results demonstrate that the modification of highly conserved physiological pathways associated with essential mitochondrial processes mediates tolerance to physiochemical stress. In addition, the same pathways, genes, and-in some instances-codons are implicated in H2S adaptation in lineages that span 40 million years of evolution

    Shoc2/Sur8 protein regulates neurite outgrowth

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    This is an openaccess article distributed under the terms of the Creative Commons Attribution License.-- et al.The Shoc2 protein has been implicated in the positive regulation of the Ras-ERK pathway by increasing the functional binding interaction between Ras and Raf, leading to increased ERK activity. Here we found that Shoc2 overexpression induced sustained ERK phosphorylation, notably in the case of EGF stimulation, and Shoc2 knockdown inhibited ERK activation. We demonstrate that ectopic overexpression of human Shoc2 in PC12 cells significantly promotes neurite extension in the presence of EGF, a stimulus that induces proliferation rather than differentiation in these cells. Finally, Shoc2 depletion reduces both NGF-induced neurite outgrowth and ERK activation in PC12 cells. Our data indicate that Shoc2 is essential to modulate the Ras-ERK signaling outcome in cell differentiation processes involved in neurite outgrowth.GL, TG and LMD were recipients of fellowships from the Ministerio de Educación y Ciencia (MEC) (to GL, TG), and Fondo de Investigaciones Sanitarias (FIS) (to LMD). LSR held a postdoctoral research contract from CIBERNED. This work was supported by FIS grant (PI10/00815) to JLO; CIBERNED to MC; SAF2008-01951, Comunidad Autónoma de Madrid (CAM) SSAL-0202-2006-01 and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED) to TI; FIS grant PI12/00775 and ISCIII-RETIC (Red Temática de Investigación Cooperativa en Cáncer) RD12/0036/0027 from the Instituto de Salud Carlos III to PSG; and FIS grants (PI09/0562 and PI13/00703), ISCIIIRETIC (RD06/0020/0003 and RD12/0036/0021), and the Spanish Association Against Cancer (AECC) to JMR.Peer Reviewe
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