509 research outputs found

    Ultrasonic propagation in gases at high temperatures

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    Ultrasonic pulse method /1 to 3 MHz/ measures both sound speed and absorption in monatomic and polyatomic gases in a temperature range of 300 to 20000 degrees K at atmospheric pressure. Helium, nitrogen, oxygen, and argon are investigated

    RISK ANALYSIS OF ADOPTING ZERO RUNOFF SUBIRRIGATION SYSTEMS IN GREENHOUSE OPERATIONS: A MONTE CARLO SIMULATION APPROACH

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    Zero runoff subirrigation (ZRS) technology can effectively manage fertilizer input while improving greenhouse production efficiency. However, high capital investment costs and inadequate technical information to growers are impediments for adoption. A Monte Carlo simulation was used to compare the profitability and risks of alternative ZRS system investments for greenhouse operations in the northeastern and north central United States. Results showed that the Dutch movable tray system and the flood floor system were most profitable and least risky for small potted plant and bedding crop flat production, respectively. The trough bench system was least favorable because its profitability was low and highly volatile.Risk and Uncertainty,

    Cloud Capacity Spectrum Method: Accounting for record-to-record variability in fragility analysis using nonlinear static procedures

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    This paper investigates a number of computational issues related to the use of nonlinear static procedures in fragility analysis of structures. Such approaches can be used to complement nonlinear dynamic procedures, reducing the computational and modelling effort. Specifically, this study assesses the performance of the Capacity Spectrum Method (CSM) with real (i.e. recorded) ground motions (as opposed to code-based conventional spectra) to explicitly account for record-to-record variability in fragility analysis. The study focuses on single-degree-of-freedom systems, providing a basis for future multi-degree-of-freedom system applications. A case-study database of 2160 inelastic oscillators is defined through parametric backbones with different elastic periods, (yield) base shear coefficients, values of the ductility capacity, hardening ratios, residual strength values and hysteresis rules. These case studies are analysed using 100 real ground motions. An efficient algorithm to perform the CSM with real spectra is proposed, combined with a cloud-based approach (Cloud-CSM) to derive fragility relationships. Simple criteria to solve the issue of multiple CSM solutions (i.e. two or more points on the backbone satisfying the CSM procedure) are proposed and tested. It is demonstrated that the performance point selection can be carried out based on a particularly efficient intensity measure detected via optimal intensity measure analysis. The effectiveness of the proposed Cloud-CSM in fragility analysis is discussed through extensive comparisons with nonlinear time-history analyses, the code-based N2 method, and a simple method involving an intensity measure as a direct proxy for the performance displacement. The Cloud-CSM provides errors lower than ±20% in predicting the median of the fragility curves in most of the analysed cases and outperforms the other considered methodologies in calculating the fragility dispersion

    arXiv:0909.2089v1 [cs.PL] 11 Sep 2009

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    Abstract. Instruction sequences with direct and indirect jump instructions are as expressive as instruction sequences with direct jump instructions only. We show that, in the case where the number of instructions is not bounded, there exist instruction sequences of the former kind from which elimination of indirect jump instructions is possible without a super-linear increase of their maximal internal delay on execution only at the cost of a super-linear increase of their length

    Contextual adaptative interfaces for Industry 4.0

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    [EN] Information technologies are intrinsically connected to the manufacturing processes, with more data generated each second. To efficiently operate machines, users must sort out information that is relevant to them in specific moments and contexts. In this paper, we propose an architecture that combines context – e.g. location, type of order, available assets, previous actions – with information established through user stereotypes

    Graft dysfunction in simultaneous pancreas kidney transplantation (SPK): Results of concurrent kidney and pancreas allograft biopsies

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    Simultaneous pancreas and kidney transplants offer significant therapeutic advantages but present a diagnostic approach dilemma in the diagnosis of rejection. Because both organs are from the same donor, the kidney has been treated traditionally as the “sentinel” organ to biopsy, presumably representing the status of both allografts. Truly concurrent biopsy studies, however, are needed to confirm this hypothesis. We examined 101 concurrent biopsies from 70 patients with dysfunction in either or both organs. Results showed concurrent rejection in 23 of 57 (40%) of cases with rejection; 19 of 57 (33.5%) and 15 of 57 (26.5%) showed kidney or pancreas only rejection, respectively. The degree and type of rejection differed in the majority (13 of 23, 56.5%) of cases with concurrent rejection, with the pancreas more often showing higher rejection grade. Taking into account pancreas dysfunction, a positive kidney biopsy should correctly predict pancreas rejection in 86% of the instances. However, the lack of complete concordance between the 2 organs, the discrepancies in grade and type of rejection, and the tendency for higher rejection grades in concurrent or pancreas only rejections, all support the rationale for pancreas biopsies. The latter provide additional data on the overall status of the organ, as well as information on nonrejection-related pathologies.Fil: Uva, Pablo Daniel. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Centro de Estudios FarmacolĂłgicos y BotĂĄnicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios FarmacolĂłgicos y BotĂĄnicos; Argentina. Instituto de NefrologĂ­a de Buenos Aires; ArgentinaFil: Papadimitriou, J. C.. University of Maryland; Estados UnidosFil: Drachenberg, Cinthia B.. University of Maryland; Estados UnidosFil: Toniolo, MarĂ­a F.. Instituto de NefrologĂ­a de Buenos Aires; ArgentinaFil: Quevedo, Alejandra. Instituto de NefrologĂ­a de Buenos Aires; ArgentinaFil: Dotta, A. C.. Instituto de NefrologĂ­a de Buenos Aires; ArgentinaFil: Chuluyan, Hector Eduardo. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Centro de Estudios FarmacolĂłgicos y BotĂĄnicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios FarmacolĂłgicos y BotĂĄnicos; ArgentinaFil: Casadei, D. H.. Instituto de NefrologĂ­a de Buenos Aires; Argentin

    Molecular evolution of the proopiomelanocortin system in Barn owl species.

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    Examination of genetic polymorphisms in outbred wild-living species provides insights into the evolution of complex systems. In higher vertebrates, the proopiomelanocortin (POMC) precursor gives rise to α-, ÎČ-, and Îł-melanocyte-stimulating hormones (MSH), which are involved in numerous physiological aspects. Genetic defects in POMC are linked to metabolic disorders in humans and animals. In the present study, we undertook an evolutionary genetic approach complemented with biochemistry to investigate the functional consequences of genetic polymorphisms in the POMC system of free-living outbred barn owl species (family Tytonidae) at the molecular level. Our phylogenetic studies revealed a striking correlation between a loss-of-function H9P mutation in the ÎČ-MSH receptor-binding motif and an extension of a poly-serine stretch in Îł3-MSH to ≄7 residues that arose in the barn owl group 6-8 MYA ago. We found that extension of the poly-serine stretches in the Îł-MSH locus affects POMC precursor processing, increasing Îł3-MSH production at the expense of Îł2-MSH and resulting in an overall reduction of Îł-MSH signaling, which may be part of a negative feedback mechanism. Extension of the Îł3-MSH poly-serine stretches ≄7 further markedly increases peptide hormone stability in plasma, which is conserved in humans, and is likely relevant to its endocrine function. In sum, our phylogenetic analysis of POMC in wild living owls uncovered a H9P ÎČ-MSH mutation subsequent to serine extension in Îł3-MSH to 7 residues, which was then followed by further serine extension. The linked MSH mutations highlight the genetic plasticity enabled by the modular design of the POMC gene

    Molecular and clinical studies in five index cases with novel mutations in the GLA gene

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    Fabry disease is a metabolic and lysosomal storage disorder caused by the functional defect of the α-galactosidase A enzyme; this defect is due to mutations in the GLA gene, that is composed of seven exons and is located on the long arm of the X-chromosome (Xq21–22). The enzymatic deficit is responsible for the accumulation of glycosphingolipids in lysosomes of different cellular types, mainly in those ones of vascular endothelium. It consequently causes a cellular and microvascular dysfunction. In this paper, we described five novel mutations in the GLA gene, related to absent enzymatic activity and typical manifestations of Fabry disease. We identified three mutations (c.846_847delTC, p.E341X and p.C382X) that lead to the introduction of a stop codon in positions 297, 341 and 382. Moreover we found a missense mutation (p.R227P) in the exon 5 of the GLA gene and a single point mutation (c.639 + 5 G > T) occurring five base pairs beyond the end of the exon 4. These mutations have never been found in our group of healthy control subjects > 2300. The studied patients presented some clinical manifestations, such as cornea verticillata, hypo-anhidrosis, left ventricular hypertrophy, cerebrovascular disorders and renal failure, that, considering the null enzymatic activity, suggest that the new mutations reported here are related to the classic form of Fabry disease. The identification of novel mutations in patients with symptomatology referable to FD increases the molecular knowledge of the GLA gene and it gives clinicians an important support for the proper diagnosis of the disease

    miRNAs in the vitreous humor of patients affected by idiopathic epiretinal membrane and macular hole

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    The aim of the present study was to assess the expression of miRNAs in the Vitreous Humor (VH) of patients with Macular Hole (MH) and Epiretinal Membrane (ERM) compared to a control group. assays. Finally, we created a biological network of differentially expressed miRNA targets and their nearest neighbors. assays of the VH of patients affected by MH and ERM, with respect to controls, showed that the most differentially expressed were miR-19b (FC -9.13, p:<0.00004), mir-24 (FC -7.52, p:<0.004) and miR-142-3p (FC -5.32, p:<0.011). Our network data showed that deregulation of differentially expressed miRNAs induces an alteration of several pathways associated with genes involved in both MH and ERM.The present study suggests that disregulation of miR-19b, miR-24 and miR-142-3p, might be related to the alterations that characterize patients affected by MH and ERM
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