346 research outputs found

    Monstrous ocean waves during typhoon Krosa

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    This paper presents a set of ocean wave time series data recorded from a discus buoy deployed near northeast Taiwan in western Pacific that was operating during the passage of Typhoon Krosa on 6 October 2007. The maximum trough-to-crest wave height was measured to be 32.3 m, which could be the largest <I>H</I><sub>max</sub> ever recorded

    Virtual Machines Performance Modeling with Support Vector Regressions

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    Virtualization is a key technology in cloudcomputing to render on-demand provisioning of virtual services.Xen, an open source paravirtualized virtual machine monitor(hypervisor), has been adopted by many leading data centersof the world today. A scheduler in Xen handles CPU resourcessharing among virtual machines hosted on the same physicalsystem. This study is focused on a scheduler in the currentXen release - the Credit scheduler. Credit uses two parameters(weight and cap) to fine tune CPU resources sharing. Previousstudies have shown that these two parameters can impact variousperformance measures of virtual machines hosted on Xen. In thisstudy, we present a holistic procedure to establish performancemodels of virtual machines. Empirical data of two commonly usedmeasures, namely calculation power and network throughput,were collected by simulations under various settings of weightand cap. We then employed a powerful machine learning tool(multi-kernel support vector regression) to learn performancemodels from the empirical data. These models were evaluatedsatisfactorily by using established procedures in machinelearning

    Freaque waves during Typhoon Krosa

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    Disruption of the glucosylceramide biosynthetic pathway in Aspergillus nidulans and Aspergillus fumigatus by inhibitors of UDP-Glc : ceramide glucosyltransferase strongly affects spore germination, cell cycle, and hyphal growth

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    The opportunistic mycopathogen Aspergillus fumigatus expresses both glucosylceramide and galactosylceramide (GlcCer and GalCer), but their functional significance in Aspergillus species is unknown. We here identified and characterized a GlcCer from Aspergillus nidulans, a non-pathogenic model fungus. Involvement of GlcCer in fungal development was tested on both species using a family of compounds known to inhibit GlcCer synthase in mammals. Two analogs, D-threo-1-phenyl-2-palmitoyl-3-pyrrolidinopropanol (P4) and D-threo-3',4'-ethylenedioxy-P4, strongly inhibited germination and hyphal growth. Neutral lipids from A. fumigatus cultured in the presence of these inhibitors displayed a significantly reduced GlcCer/GalCer ratio. These results suggest that synthesis of GlcCer is essential for normal development of A. fumigatus and A. nidulans. (C) 2002 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.Univ New Hampshire, Dept Chem, Durham, NH 03824 USAUniv Georgia, Dept Bot, Athens, GA 30602 USAUniversidade Federal de São Paulo, Dept Biochem, Escola Paulista Med, BR-04023900 São Paulo, BrazilUniv Michigan, Med Ctr, Dept Internal Med, Div Nephrol, Ann Arbor, MI 48109 USAUniv Georgia, Complex Carbohydrate Res Ctr, Athens, GA 30602 USAUniv Georgia, Dept Biochem & Mol Biol, Athens, GA 30602 USAUniversidade Federal de São Paulo, Dept Biochem, Escola Paulista Med, BR-04023900 São Paulo, BrazilWeb of Scienc

    The Anti-Apoptotic Activity of BAG3 Is Restricted by Caspases and the Proteasome

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    Caspase-mediated cleavage and proteasomal degradation of ubiquitinated proteins are two independent mechanisms for the regulation of protein stability and cellular function. We previously reported BAG3 overexpression protected ubiquitinated clients, such as AKT, from proteasomal degradation and conferred cytoprotection against heat shock. We hypothesized that the BAG3 protein is regulated by proteolysis. caspase-resistant mutant. Caspase and proteasome inhibition resulted in partial and independent protection of BAG3 whereas inhibitors of both blocked BAG3 degradation. STS-induced apoptosis was increased when BAG3 was silenced, and retention of BAG3 was associated with cytoprotection.BAG3 is tightly controlled by selective degradation during STS exposure. Loss of BAG3 under STS injury required sequential caspase cleavage followed by polyubiquitination and proteasomal degradation. The need for dual regulation of BAG3 in apoptosis suggests a key role for BAG3 in cancer cell resistance to apoptosis

    Monstrous ocean waves during typhoon Krosa

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    Determination of total and available fractions of PAHs by SPME in oily wastewaters : overcoming interference from NAPL and NOM

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    Background, aim, and scope Polycyclic aromatic hydrocarbons (PAHs) are often found in oily wastewaters. Their presence is usually the result of human activities and has a negative effect on the environment. One important step in addressing this problem is to evaluate the effectiveness of PAH removal by biological processes since these are the most cost-effective treatments known today. Many techniques are presently available for PAH determination in wastewaters. Solid phase microextracion (SPME) is known to be one of the most effective techniques for this purpose. When analyzing complex matrices with substances such as natural organic matter (NOM) and non-aqueous phase liquids (NAPL), it is important to differentiate the free dissolved PAH from matrix-bonded PAH. PAHs associated with the bonded fraction are less susceptible to biological treatment. The present study concerns the development of a simple and suitable methodology for the determination of the freely dissolved and the total fraction of PAHs present in oily wastewaters. The methodology was then applied to an oily wastewater from a fuel station retention basin. Material and methods Headspace SPME was used for analyzing PAH since the presence of a complex or dirty matrix in direct contact with the fiber may damage it. Four model PAHs—anthracene, fluorene, phenanthrene, and pyrene—were analyzed by GC-MS. Negligible depletion SPME technique was used to determine the free fraction. Total PAH was determined by enhancing the mass transfer from the bonded phase to the freely dissolved phase by temperature optimization and the use of the method of standard additions. The PAH absorption kinetics were determined in order to define the optimal sampling conditions for this method. The fitting of the experimental data to a mathematical model was accomplished using Berkeley Madonna software. Humic acid and silicon oil were used as model NOM and NAPL, respectively, to study the effect of these compounds on the decrease of SPME response. Then, the method was evaluated with wastewater from a fuel station spill retention basin. Results The SPME kinetic parameters—k 1 (uptake rate), k 2 (desorption rate), and K SPME (partition coefficient)—were determined from experimental data modeling. The determination of the free fraction required 15-min sampling to ensure that PAH depletion from sample was below 1%. For total PAH, a 30-min extraction at 100°C ensured the maximum signal response in the GC-MS. For the determination of free and total PAHs, extractions were performed before reaching the SPME equilibrium. The wastewater used in this study had no free fraction of the analyzed PAHs. However, the four studied PAHs were found when the method for total PAH was used. Discussion The addition of NOM and NAPL dramatically decreased the efficiency of the SPME. This decrease was the result of a greater partition of the PAHs to the NAPL and NOM phases. This fact was also observed in the analysis of the fuel station spill retention basin, where no free PAH was measured. However, using the method of standard addition for the determination of total PAH, it was possible to quantify all four PAHs. Conclusions The method developed in the present study was found to be adequate to differentiate between free and total PAH present in oily wastewater. It was determined that the presence of NOM and NAPL had a negative effect on SPME efficiency. Recommendations and perspectives The presence of binding substances had a great influence on SPME kinetics. Therefore, it is of extreme importance to determine their degree of interference when analyzing oily wastewaters or results can otherwise be erroneous. Other factors influencing the total PAH determinations should be considered in further studies.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/ 18816/2004, POCI/AMB/61044/200

    BAG1: The Guardian of Anti-Apoptotic Proteins in Acute Myeloid Leukemia

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    BCL2 associated Athano-Gene 1 (BAG1) is a multifunctional protein that has been described to be involved in different cell processes linked to cell survival. It has been reported as deregulated in diverse cancer types. Here, BAG1 protein was found highly expressed in children with acute myeloid leukemia at diagnosis, and in a cohort of leukemic cell lines. A silencing approach was used for determining BAG1's role in AML, finding that its down-regulation decreased expression of BCL2, BCL-XL, MCL1, and phospho-ERK1/2, all proteins able to sustain leukemia, without affecting the pro-apoptotic protein BAX. BAG1 down-regulation was also found to increase expression of BAG3, whose similar activity was able to compensate the loss of function of BAG1. BAG1/BAG3 co-silencing caused an enhanced cell predisposition to death in cell lines and also in primary AML cultures, affecting the same proteins. Cell death was CASPASE-3 dependent, was accompanied by PARP cleavage and documented by an increased release of pro-apoptotic molecules Smac/DIABLO and Cytochrome c. BAG1 was found to directly maintain BCL2 and to protect MCL1 from proteasomal degradation by controlling USP9X expression, which appeared to be its novel target. Finally, BAG1 was found able to affect leukemia cell fate by influencing the expression of anti-apoptotic proteins crucial for AML maintenance

    Changes in bone turnover and bone loss in HIV-infected patients changing treatment to tenofovir-emtricitabine or abacavir-lamivudine

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    BACKGROUND: Those receiving tenofovir/emtricitabine (TDF-FTC) had greater bone loss compared with abacavir/lamivudine (ABC-3TC) in a randomized simplification trial (STEAL study). Previous studies associated increased bone turnover and bone loss with initiation of antiretroviral treatment, however it is unclear whether change in bone mineral density (BMD) was a result of specific drugs, from immune reconstitution or from suppression of HIV replication. This analysis determined predictors of BMD change in the hip and spine by dual-energy x-ray absorptiometry in virologically suppressed participants through week 96. METHODOLOGY/PRINCIPAL FINDINGS: Bone turnover markers (BTMS) tested were: formation [bone alkaline phosphatase, procollagen type 1 N-terminal propeptide (P1NP)]; resorption (C-terminal cross-linking telopeptide of type 1 collagen [CTx]); and bone cytokine-signalling (osteoprotegerin, RANK ligand). Independent predictors of BMD change were determined using forward, stepwise, linear regression. BTM changes and fracture risk (FRAX®) at week 96 were compared by t-test. Baseline characteristics (n = 301) were: 98% male, mean age 45 years, current protease-inhibitor (PI) 23%, tenofovir/abacavir-naïve 52%. Independent baseline predictors of greater hip and spine bone loss were TDF-FTC randomisation (p ≤ 0.013), lower fat mass (p-trend ≤ 0.009), lower P1NP (p = 0.015), and higher hip T score/spine BMD (p-trend ≤ 0.006). Baseline PI use was associated with greater spine bone loss (p = 0.004). TDF-FTC increased P1NP and CTx through Wk96 (p<0.01). Early changes in BTM did not predict bone loss at week 96. No significant between-group difference was found in fracture risk. CONCLUSIONS/SIGNIFICANCE: Tenofovir/emtricitabine treatment, lower bone formation and lower fat mass predicted subsequent bone loss. There was no association between TDF-FTC and fracture risk.Hila Haskelberg, Jennifer F. Hoy, Janaki Amin, Peter R. Ebeling, Sean Emery, Andrew Carr, STEAL Study Grou
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