1,842 research outputs found

    Chemical treatment makes aromatic polyamide fabric fireproof in oxygen atmosphere

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    Organic fabric is reacted first with vapors of a phosphorus oxychloride, phosphorus oxybromide solution and then with bromine vapor, after neutralization it is flameproof in pure oxygen atmosphere. Soaking the fabric with mixture of ammonium polyphosphates increases flame resistance, but the polyphosphates are leached out during laundering

    Le Chasselas Gros Coulard - Mutant TĂ©traploĂŻde

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    Le Chasselas Gros Coulard est une mutation tĂ©traploĂŻde comme le prouvent la numĂ©ration des chromosomes et l' examen des caractĂšres secondaires comme la taille des stomates, des pĂ©pins et des baies, le nombre de chloroplastes des cellules pĂ©ristomatiques.Il est probablement possible d'obtenir par semis des types tĂ©traploĂŻdes plus fertiles. Ceux-ci prĂ©senteraient un gros intĂ©rĂȘt pratique pour la production du raisin de table, du fait de la taille de leurs baies

    Observations sur le cycle du detérminisme de la production chez la Vigne à l'occasion de la mise au point d'une méthode d'infection artificielle par le mildiou (Plasmopara viticola) pour l'évaluation des fongicides au champ

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    L'Ă©tude biomĂ©trique d'un essai destine Ă  la mise au point d'une mĂ©thode d'appreciation de la valeur de produits fongicides (anti-mildiou), montre que la technique de brumisation permet de faire des essais valides mĂȘme dans des conditions climatiques peu propices au mildiou car on obtient une infection sĂ©vĂšre et uniforme, et l'ordre de classement des produits est sensiblement Je meme qu'en conditions naturelles.Les plantes ayant subi des destructions du feuillage trĂšs diverses suivant les traitements on Ă©tĂ© Ă©tudiĂ©es pendant trois ans. Cette Ă©tude dĂ©montre l'existence du cycle de trois ans: constitution de rĂ©serves, initiation florale, production de grappes dĂ©jĂ  postulĂ© par ailleurs.Observations on the cycle determining the yield of the grapevine made while perfecting a method of artificial infection by mildew (Plasmopara viticola) in order to evaluate fungicides in the fieldSpraying a water mist ("brumisation") during the summer months results in a strong and even downy mildew infection on one year old rooted vine cuttings grown in the field. This makes comparative trials of fungicides possible even in unfavourable (dry) years.Such a trial, involving four levels (spray formulations) of the fungicides factor, two levels (with or without) of the mist factor, with five replications in plots of six plants, resulted in a set of plants having suffered various degrees of foliage destruction. Measuring these plants during three successive years, starting with the differential treatment year, provided the basis for checking an hypothesis on the determination of yield in the grapevine.Progressive analysis of variance of regressions (WooLF 1951) was used in the interpretation of results.Vigour in the second year was negatively correlated with foliar damage in the first year. In turn, number of bunches in the third year was correlated with vigour in the second year, hence with foliar damage in the first year.This lends support to the hypothesis that, in the grapevine, there is a three year cycle leading to the harvested clusters.On an adult plant, three cycles are simultaneously at work at every moment. These cycles are competing for energy fixed by photosynthesls; hormonal correlations that may be correlated with energy (carbohydrates) storage, for instance through its influence on root system volume, are also at play.The implications of these results, especially for experimental work with the grapevine, are discussed

    Functional cartography of complex metabolic networks

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    High-throughput techniques are leading to an explosive growth in the size of biological databases and creating the opportunity to revolutionize our understanding of life and disease. Interpretation of these data remains, however, a major scientific challenge. Here, we propose a methodology that enables us to extract and display information contained in complex networks. Specifically, we demonstrate that one can (i) find functional modules in complex networks, and (ii) classify nodes into universal roles according to their pattern of intra- and inter-module connections. The method thus yields a ``cartographic representation'' of complex networks. Metabolic networks are among the most challenging biological networks and, arguably, the ones with more potential for immediate applicability. We use our method to analyze the metabolic networks of twelve organisms from three different super-kingdoms. We find that, typically, 80% of the nodes are only connected to other nodes within their respective modules, and that nodes with different roles are affected by different evolutionary constraints and pressures. Remarkably, we find that low-degree metabolites that connect different modules are more conserved than hubs whose links are mostly within a single module.Comment: 17 pages, 4 figures. Go to http://amaral.northwestern.edu for the PDF file of the reprin

    Observation of the B0 →ρ0ρ0 decay from an amplitude analysis of B0 → (π+π-) (π+π-) decays

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    Proton-proton collision data recorded in 2011 and 2012 by the LHCb experiment, corresponding to an integrated luminosity of 3.0 fb−1 , are analysed to search for the charmless B0 → ρ 0ρ 0 decay. More than 600 B0 → (π +π −)(π +π −) signal decays are selected and used to perform an amplitude analysis, under the assumption of no CP violation in the decay, from which the B0 → ρ 0ρ 0 decay is observed for the first time with 7.1 standard deviations significance. The fraction of B0 → ρ 0ρ 0 decays yielding a longitudinally polarised final state is measured to be fL = 0.745+0.048 −0.058(stat) ± 0.034(syst). The B0 → ρ 0ρ 0 branching fraction, using the B0 → φK∗ (892)0 decay as reference, is also reported as B(B0 → ρ 0ρ 0 ) = (0.94 ± 0.17(stat) ± 0.09(syst) ± 0.06(BF)) × 10−6

    Unusual presentation of thyrotoxicosis as complete heart block and renal failure: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Thyrotoxicosis is a clinical entity often very difficult to diagnose without biochemical confirmation as its clinical features can be highly varied. The most common cardiac manifestations of thyrotoxicosis are resting sinus tachycardia, supraventricular tachycardia including atrial fibrillation and atrial flutter with or without cardiac failure. Bradycardia and atrio-ventricular conduction defects are very uncommon in thyrotoxicosis.</p> <p>Case presentation</p> <p>We report the case of a 59-year-old Caucasian man presenting with progressive weight loss, abnormal liver function, acute renal failure and complete heart block due to thyrotoxicosis.</p> <p>Conclusion</p> <p>Thyrotoxicosis should be considered as a possible diagnosis in patients with bradycardia and heart blocks associated with abnormal symptoms like weight loss. Nevertheless, the clinical, electrophysiological and biochemical abnormalities associated with thyrotoxicosis may be completely reversible restoring euthyroid state.</p

    Mesoscopic organization reveals the constraints governing C. elegans nervous system

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    One of the biggest challenges in biology is to understand how activity at the cellular level of neurons, as a result of their mutual interactions, leads to the observed behavior of an organism responding to a variety of environmental stimuli. Investigating the intermediate or mesoscopic level of organization in the nervous system is a vital step towards understanding how the integration of micro-level dynamics results in macro-level functioning. In this paper, we have considered the somatic nervous system of the nematode Caenorhabditis elegans, for which the entire neuronal connectivity diagram is known. We focus on the organization of the system into modules, i.e., neuronal groups having relatively higher connection density compared to that of the overall network. We show that this mesoscopic feature cannot be explained exclusively in terms of considerations, such as optimizing for resource constraints (viz., total wiring cost) and communication efficiency (i.e., network path length). Comparison with other complex networks designed for efficient transport (of signals or resources) implies that neuronal networks form a distinct class. This suggests that the principal function of the network, viz., processing of sensory information resulting in appropriate motor response, may be playing a vital role in determining the connection topology. Using modular spectral analysis, we make explicit the intimate relation between function and structure in the nervous system. This is further brought out by identifying functionally critical neurons purely on the basis of patterns of intra- and inter-modular connections. Our study reveals how the design of the nervous system reflects several constraints, including its key functional role as a processor of information.Comment: Published version, Minor modifications, 16 pages, 9 figure

    Fertility preservation in boys : recent developments and new insights

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    BACKGROUND: Infertility is an important side effect of treatments used for cancer and other non-malignant conditions in males. This may be due to the loss of spermatogonial stem cells (SSCs) and/or altered functionality of testicular somatic cells (e.g. Sertoli cells, Leydig cells). Whereas sperm cryopreservation is the first-line procedure to preserve fertility in post-pubertal males, this option does not exist for prepubertal boys. For patients unable to produce sperm and at high risk of losing their fertility, testicular tissue freezing is now proposed as an alternative experimental option to safeguard their fertility. OBJECTIVE AND RATIONALE: With this review, we aim to provide an update on clinical practices and experimental methods, as well as to describe patient management inclusion strategies used to preserve and restore the fertility of prepubertal boys at high risk of fertility loss. SEARCH METHODS: Based on the expertise of the participating centres and a literature search of the progress in clinical practices, patient management strategies and experimental methods used to preserve and restore the fertility of prepubertal boys at high risk of fertility loss were identified. In addition, a survey was conducted amongst European and North American centres/networks that have published papers on their testicular tissue banking activity. OUTCOMES: Since the first publication on murine SSC transplantation in 1994, remarkable progress has been made towards clinical application: cryopreservation protocols for testicular tissue have been developed in animal models and are now offered to patients in clinics as a still experimental procedure. Transplantation methods have been adapted for human testis, and the efficiency and safety of the technique are being evaluated in mouse and primate models. However, important practical, medical and ethical issues must be resolved before fertility restoration can be applied in the clinic. Since the previous survey conducted in 2012, the implementation of testicular tissue cryopreservation as a means to preserve the fertility of prepubertal boys has increased. Data have been collected from 24 co-ordinating centres worldwide, which are actively offering testis tissue cryobanking to safeguard the future fertility of boys. More than 1033 young patients (age range 3 months to 18 years) have already undergone testicular tissue retrieval and storage for fertility preservation. LIMITATIONS, REASONS FOR CAUTION: The review does not include the data of all reproductive centres worldwide. Other centres might be offering testicular tissue cryopreservation. Therefore, the numbers might be not representative for the entire field in reproductive medicine and biology worldwide. The key ethical issue regarding fertility preservation in prepubertal boys remains the experimental nature of the intervention. WIDER IMPLICATIONS: The revised procedures can be implemented by the multi-disciplinary teams offering and/or developing treatment strategies to preserve the fertility of prepubertal boys who have a high risk of fertility loss.Peer reviewe

    Quantum numbers of the X (3872 ) state and orbital angular momentum in its ρ0J /ψ decay

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    Angular correlations in B+ → X(3872)K+ decays, with X(3872) → ρ 0J/ψ, ρ 0 → π +π − and J/ψ → ” +” −, are used to measure orbital angular momentum contributions and to determine the J P C value of the X(3872) meson. The data correspond to an integrated luminosity of 3.0 fb−1 of proton-proton collisions collected with the LHCb detector. This determination, for the first time performed without assuming a value for the orbital angular momentum, confirms the quantum numbers to be J P C = 1++. The X(3872) is found to decay predominantly through S wave and an upper limit of 4% at 95% C.L. is set on the D-wave contribution
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