31 research outputs found

    Aspects of the breeding biology of Janaira gracilis Moreira & Pires (Crustacea, Isopoda, Asellota)

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    The biological aspects of incubating females of Janaira gracilis Mbreira & Pires, are described. The marsupium is formed by 4 pairs of oostegites arising from pereopods I-IV. The oostegites appear for the first time at the post-marsupial stage 7 (preparatory stage 1), growing successively at each moult until stage 9 (brooding stage 1), when they reach fully development. The sizes of the eggs increase with the body size of the females. The number of eggs, per female, is a linear function of the body volume, i.e., the fecundity increases with the female's body size. The number of eggs, embryos and juveniles decrease during the marsupial development. This decrease in brood number is higher between the last two marsupial stages, i.e., from stage C to D, than between the preceding marsupial stages. The average and overall brood mortality rate is of 38.95%.São descritos, no presente trabalho, vários aspectos relacionados à biologia de fêmeas grávidas de Janaira gracilis Moreira & Pires. O marsúpio é formado por 4 pares de oostégitos, que partem dos pereópodos I-IV. Os oostégitos, que surgem pela primeira vez no estádio 7 do desenvolvimento pós-marsupial (estágio preparatório 1), crescem nas sucessivas mudas, atingindo no estágio 9 (estágio reprodutor 1) seu pleno desenvolvimento. O tamanho dos ovos é proporcional ao tamanho das fêmeas. O número de ovos, por fêmeas, e proporcional ao volume das fêmeas, isto é, a fecundidade é mais elevada nos exemplares de maior comprimento. O número de ovos, embriões e jovens decresce com o desenvolvimento marsupial, sendo este decréscimo maior entre os dois últimos estágios marsupials (i.é., entre os estágios C e D) do que entre os estágios precedentes. A taxa média de mortalidade marsupial é de 38.95%

    Multiomic ALS signatures highlight subclusters and sex differences suggesting the MAPK pathway as therapeutic target

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    Amyotrophic lateral sclerosis (ALS) is a debilitating motor neuron disease and lacks effective disease-modifying treatments. This study utilizes a comprehensive multiomic approach to investigate the early and sex-specific molecular mechanisms underlying ALS. By analyzing the prefrontal cortex of 51 patients with sporadic ALS and 50 control subjects, alongside four transgenic mouse models (C9orf72-, SOD1-, TDP-43-, and FUS-ALS), we have uncovered significant molecular alterations associated with the disease. Here, we show that males exhibit more pronounced changes in molecular pathways compared to females. Our integrated analysis of transcriptomes, (phospho)proteomes, and miRNAomes also identified distinct ALS subclusters in humans, characterized by variations in immune response, extracellular matrix composition, mitochondrial function, and RNA processing. The molecular signatures of human subclusters were reflected in specific mouse models. Our study highlighted the mitogen-activated protein kinase (MAPK) pathway as an early disease mechanism. We further demonstrate that trametinib, a MAPK inhibitor, has potential therapeutic benefits in vitro and in vivo, particularly in females, suggesting a direction for developing targeted ALS treatments

    Technology and the Era of the Mass Army

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    Numerical and experimental study of post-heat treatment gas quenching and its impact on microstructure and creep in CMSX-10 superalloy

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    The gas quenching process at the end of solution heat treatment and its influence on microstructure and creep properties of the single crystal superalloy CMSX-10 was studied using numerical and experimental techniques. Computational fluid dynamics was used to model the turbulent flow field in the furnace during quenching. Boundary conditions were obtained by measuring the pressure drop across the chamber. The calculated flow velocities for a range of process conditions were in reasonable agreement with the ones measured using a Pitot tube; differences were mainly attributed to the unsteady nature of the turbulent flow. The resulting cooling rates in the furnace load were quantified with higher cooling rates leading to smaller γ′ precipitates. Asymmetry of the flow field leads to variations in γ′ size. This can be reduced by changing the way turbine blades are placed in the furnace. Creep tests demonstrated that this can have a significant effect on the creep properties of the material. At low temperatures (850 C), specimens with larger γ′ particles showed better creep performance, with less pronounced primary creep. At high temperatures (1100 C) small γ′ size showed a slight advantage. © 2013 Elsevier B.V

    Numerical Modeling of Vacuum Heat Treatment of Nickel-based Superalloys

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    Numerical modeling is carried out of the heat transfer effects arising during heat treatment of single-crystal nickel-based superalloys, of the type used for high pressure turbine blades in jet engines. For these components, fine control of the thermal history during processing is needed to avoid incipient melting and to develop the properties needed for service applications. Computational fluid dynamics methods are employed for the analysis. The modeling is used to predict the temporal evolution of the temperature distribution inside the treated component, to calculate heat transfer coefficients, and to analyze the homogeneity of heat transfer. The impact of the boundary conditions is investigated with particular emphasis on the temperature of the heating elements. Its value was derived from an analytical model of the furnace using effective view factors. The predictions of the modeling are tested against measurements made on laboratory-scale apparatus containing features of production-scale equipment. © 2013 The Minerals, Metals and Materials Society and ASM International

    Linear Friction Welding of Titanium Alloys for Aeroengine Applications: Modelling and Validation

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    A model is presented for the linear friction welding process used for blisk manufacture in modern aeroengines. Both the conditioning and equilibrium phases are accounted for. The heating is accomplished by applying an interfacial friction condition. The separate workpieces are assumed to be joined after reaching a critical, predefined temperature. The subsequent equilibrium phase is modelled as a single workpiece, with the usual rippled flash formation occurring. The predictions of the model are compared critically against the results of targeted experimentation, e.g. upsets rates and temperature cycles. Copyright © 2013 ASM International® All rights reserved
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