1,375 research outputs found

    Purified human BRCA2 stimulates RAD51-mediated recombination.

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    Mutation of the breast cancer susceptibility gene, BRCA2, leads to breast and ovarian cancers. Mechanistic insight into the functions of human BRCA2 has been limited by the difficulty of isolating this large protein (3,418 amino acids). Here we report the purification of full-length BRCA2 and show that it both binds RAD51 and potentiates recombinational DNA repair by promoting assembly of RAD51 onto single-stranded DNA (ssDNA). BRCA2 acts by targeting RAD51 to ssDNA over double-stranded DNA, enabling RAD51 to displace replication protein-A (RPA) from ssDNA and stabilizing RAD51-ssDNA filaments by blocking ATP hydrolysis. BRCA2 does not anneal ssDNA complexed with RPA, implying it does not directly function in repair processes that involve ssDNA annealing. Our findings show that BRCA2 is a key mediator of homologous recombination, and they provide a molecular basis for understanding how this DNA repair process is disrupted by BRCA2 mutations, which lead to chromosomal instability and cancer

    Too Litter, Too Late: Economic Logistics of Transporting Nutrient-Rich Poultry Litter Out of Nutrient-Saturated Regions

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    Export of excess litter from concentrated animal production regions has become a pressing issue. A break even price for poultry litter in nutrient-deficient areas was identified through a math programming model using willingness to pay data from crop producers. Results indicate that a $16 subsidy is needed to sustain a long-term poultry litter market.Environmental Economics and Policy,

    Economics of Transporting Poultry Litter from Northwest Arkansas to Eastern Arkansas Croplands

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    Applying baled litter from northwest Arkansas shipped by truck with backhauls, supplemented with chemical fertilizers provided the most cost-efficient method to supply nutrients to crops in eastern Arkansas, according to a GAMS optimization. Shipping raw litter by truck and barge is the optimal choice when backhauls or baling is unavailable.Public Economics,

    Fusion proteins towards fungi and bacteria in plant protection

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    Research ArticleIn agriculture, although fungi are considered the foremost problem, infections by bacteria also cause significant economical losses. The presence of different diseases in crops often leads to a misuse of the proper therapeutic, or the combination of different diseases forces the use of more than one pesticide. This work concerns the development of a ‘super-Blad’: a chimeric protein consisting of Blad polypeptide, the active ingredient of a biological fungicide already on the market, and two selected peptides, SP10-5 and Sub5, proven to possess biological potential as antibacterial agents. The resulting chimeric protein obtained from the fusion of Blad with SP10-5 not only maintained strong antibacterial activity, especially against Xanthomonas spp. and Pseudomonas syringae, but was also able to retain the ability to inhibit the growth of both yeast and filamentous fungi. However, the antibacterial activity of Sub5 was considerably diminished when fused with Blad, which seems to indicate that not all fusion proteins behave equally. These newly designed drugs can be considered promising compounds for use in plant protection. A deeper and focused development of an appropriate formulation may result in a potent biopesticide that can replace, per se, two conventional chemistries with less impact on the environmentinfo:eu-repo/semantics/publishedVersio

    Oxidative Stress Induced by Excess of Adiposity Is Related to a Downregulation of Hepatic SIRT6 Expression in Obese Individuals

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    Sirt6 is a member of the sirtuin family involved in physiological and pathological processes including aging, cancer, obesity, diabetes, and energy metabolism. This study is aimed at evaluating the relationship between liver SIRT6 gene expression and the oxidative stress network depending on adiposity levels in Zucker rats, an animal model of metabolic syndrome. We observed that liver-specific SIRT6 expression is reduced in an in vivo model of spontaneous obesity and metabolic syndrome. We also observed that SIRT6 expression in the liver is positively associated with SIRT1 and GST-M2 expressions, two proteins involved in antioxidant protection pathways and inversely related to body weight and plasmatic oxidative status. Interestingly, the SIRT6 expression is upregulated after energy restriction-induced weight loss concomitantly with an improvement in oxidative stress markers. These results suggest that SIRT6 may be a potential therapeutic target for the treatment of obesity and associated metabolic disorders, such as liver disease.Centro de Investigacion Biomedica en Red de Fisiopatologia de la Obesidad y Nutricion (CIBERobn)Instituto de Salud Carlos IIIEuropean Regional Development Fund (FEDER

    The Impact of Depression on Patient Outcomes in Hip Arthroscopic Surgery.

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    Background: Mental health impairments have been shown to negatively affect preoperative self-reported function in patients with various musculoskeletal disorders, including those with femoroacetabular impingement. Hypothesis: Those with symptoms of depression will have lower self-reported function, more pain, and less satisfaction on initial assessment and at 2-year follow-up than those without symptoms of depression. Study Design: Cohort study; Level of evidence, 3. Methods: Patients who were enrolled in a multicenter hip arthroscopic surgery registry and had 2-year outcome data available were included in the study. Patients completed the 12-item International Hip Outcome Tool (iHOT-12), visual analog scale (VAS) for pain, and 12-item Short-Form Health Survey (SF-12) when consenting for surgery. At 2-year follow-up, patients were emailed the iHOT, the VAS, and a rating scale of surgical satisfaction. Initial SF-12 mental component summary (MCS) scores Results: A total of 781 patients achieved the approximate 2-year milestone (mean follow-up, 735 ± 68 days), with 651 (83%) having 2-year outcome data available. There were 434 (67%) female and 217 (33%) male patients, with a mean age of 35.8 ± 13.0 years and a mean body mass index of 25.4 ± 8.8 kg/m Conclusion: A large number of patients who underwent hip arthroscopic surgery presented with symptoms of depression, which negatively affected self-reported function, pain levels, and satisfaction on initial assessment and at 2-year follow-up. Surgeons who perform hip arthroscopic surgery may need to identify the symptoms of depression and be aware of the impact that depression can have on surgical outcomes

    Asymmetric Induction in Intramolecular [2 + 2]-Photocycloadditions of 1,3-Disubstituted Allenes with Enones and Enoates

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    Irradiation of optically active allenes (89-92% ee) appended to enones and enoates affords alkylidenecyclobutane photoadducts with high levels of asymmetric induction (83-100%) derived exclusively from the allene fragment. The substrates studied include allenes tethered to enones such as 1,3-cyclohexanedionea nd 1,3-cyclopentanedione, as well as allenes tethered to functionalized coumarins. The enantiomer ratios of the photoadducts were quantified by derivatization of the products as the corresponding Mosher MTPA esters and analysis by ^1H NMR spectroscopy. The exo-methylenecyclobutanes obtained upon irradiation of allene-mumarins are isolated as single olefin diastereomers. Irradiation of a coumarin tethered at C(5) with an optically active allene affords an alkynyl-substituted oxepane with complete asymmetric induction

    Le médecin, son patient et ses pairs:Une nouvelle approche de la relation thérapeutique

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    Les travaux relatifs à la relation thérapeutique ont jusqu'alors négligé un élément décisif: les relations entre médecins. Le cas de la cancérologie révèle que l'attention portée à ces relations est susceptible d'apporter un nouvel éclairage à la compréhension de la relation thérapeutique. En particulier, la concurrence entre médecins sur l'activité et sur la définition du bon traitement représente une incertitude supplémentaire majeure pour chaque médecin dans sa tentative de maîtriser la relation avec son patient. Dès lors, les stratégies médicales d'organisation et de réorganisation locale de la prise en charge peuvent s'analyser comme des tentatives de réduction de cette incertitude. Réciproquement, la relation au patient n'a pas pour seule fin la guérison mais constitue aussi un autre moyen de maîtriser cette incertitude et, consécutivement, d'améliorer les relations thérapeutiques futures : le patient est pour le médecin un moyen d'obtenir de l'information sur les comportements de ses pairs et un moyen d'échange pour entretenir des relations privilégiées avec certains d'entre eux

    Escuro: o que existe no espaço e no imaginário da criança

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    O estudo sociológico da noite tem-se centrado em temas como o risco, o desvio, a segurança, a solidão e, mais recentemente, o sono. Através do olhar das crianças, a noite é principalmente o escuro. De que modo é que as crianças percecionam o escuro? Que atores, rituais, regras e objetos dele fazem parte? Foi desenvolvido um estudo exploratório, de tipo qualitativo, com crianças com idades compreendidas entre os 7 e os 9 anos de idade. Numa primeira fase foi solicitado às crianças que realizassem um desenho sobre o modo como veem o escuro. Posteriormente, e tomando o desenho como recurso, foi aplicada uma entrevista-conversa. Os resultados obtidos permitem romper com uma leitura adultocêntrica e frequentemente limitada que opõe o dia e a noite como períodos de brincadeira e de descanso para as crianças e, dentro deste último, as crianças que têm e não têm medo do escuro
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