884 research outputs found
AliEn Resource Brokers
AliEn (ALICE Environment) is a lightweight GRID framework developed by the
Alice Collaboration. When the experiment starts running, it will collect data
at a rate of approximately 2 PB per year, producing O(109) files per year. All
these files, including all simulated events generated during the preparation
phase of the experiment, must be accounted and reliably tracked in the GRID
environment. The backbone of AliEn is a distributed file catalogue, which
associates universal logical file name to physical file names for each dataset
and provides transparent access to datasets independently of physical location.
The file replication and transport is carried out under the control of the File
Transport Broker. In addition, the file catalogue maintains information about
every job running in the system. The jobs are distributed by the Job Resource
Broker that is implemented using a simplified pull (as opposed to traditional
push) architecture. This paper describes the Job and File Transport Resource
Brokers and shows that a similar architecture can be applied to solve both
problems.Comment: 5 pages, 8 figures, CHEP 03 conferenc
AliEnFS - a Linux File System for the AliEn Grid Services
Among the services offered by the AliEn (ALICE Environment
http://alien.cern.ch) Grid framework there is a virtual file catalogue to allow
transparent access to distributed data-sets using various file transfer
protocols. (AliEn File System) integrates the AliEn file catalogue as
a new file system type into the Linux kernel using LUFS, a hybrid user space
file system framework (Open Source http://lufs.sourceforge.net). LUFS uses a
special kernel interface level called VFS (Virtual File System Switch) to
communicate via a generalised file system interface to the AliEn file system
daemon. The AliEn framework is used for authentication, catalogue browsing,
file registration and read/write transfer operations. A C++ API implements the
generic file system operations. The goal of AliEnFS is to allow users easy
interactive access to a worldwide distributed virtual file system using
familiar shell commands (f.e. cp,ls,rm ...) The paper discusses general aspects
of Grid File Systems, the AliEn implementation and present and future
developments for the AliEn Grid File System.Comment: 9 pages, 12 figure
A Configuration Management and Monitoring Toolkit for EOS and Kinetic Drive Cluster
Abstract
EOS is a simple storage software solution to manage multi PB storage at CERN. Seagate ki
Abstract
EOS is a simple storage software solution to manage multi PB storage at CERN. Seagate kinetic drives have been interfaced with the CERN EOS disk storage system abstracting multiple drives as a cluster. Drive cluster are managed by EOS like a single storage mount point. Each drive cluster, access keys and the cluster layout is described in a JSON file. Monitoring EOS and managing configuration files for thousands of disks was inefficient. This project aimed at the development of a web toolkit for configuration management and monitoring of thousands of kinetic drives and EOS via a simple web interface. The proposed application allows to define, modify and publish kinetic drive cluster configurations and to monitor key statistics and individual drive parameters on demand. In this report, I cover how I went about building this toolkit.
Keywords: EOS, Configuration Management, Monitor, Kinetic Drives, AngularJS, Drive clus-ter, CERN storage, Seagate, Performance Optimization
-netic drives have been interfaced with the CERN EOS disk storage system abstracting multiple drives as a cluster. Drive cluster are managed by EOS like a single storage mount point. Each drive cluster, access keys and the cluster layout is described in a JSON file. Monitoring EOS and managing configuration files for thousands of disks was inefficient. This project aimed at the development of a web toolkit for configuration management and monitoring of thousands of kinetic drives and EOS via a simple web interface. The proposed application allows to define, modify and publish kinetic drive cluster configurations and to monitor key statistics and individual drive parameters on demand. In this report, I cover how I went about building this toolkit.
Keywords: EOS, Configuration Management, Monitor, Kinetic Drives, AngularJS, Drive clus-ter, CERN storage, Seagate, Performance Optimizatio
Vacuole membrane fusion: V0 functions after trans-SNARE pairing and is coupled to the Ca2+-releasing channel
Pore models of membrane fusion postulate that cylinders of integral membrane proteins can initiate a fusion pore after conformational rearrangement of pore subunits. In the fusion of yeast vacuoles, V-ATPase V0 sectors, which contain a central cylinder of membrane integral proteolipid subunits, associate to form a transcomplex that might resemble an intermediate postulated in some pore models. We tested the role of V0 sectors in vacuole fusion. V0 functions in fusion and proton translocation could be experimentally separated via the differential effects of mutations and inhibitory antibodies. Inactivation of the V0 subunit Vph1p blocked fusion in the terminal reaction stage that is independent of a proton gradient. Δvph1 mutants were capable of docking and trans-SNARE pairing and of subsequent release of lumenal Ca2+, but they did not fuse. The Ca2+-releasing channel appears to be tightly coupled to V0 because inactivation of Vph1p by antibodies blocked Ca2+ release. Vph1 deletion on only one fusion partner sufficed to severely reduce fusion activity. The functional requirement for Vph1p correlates to V0 transcomplex formation in that both occur after docking and Ca2+ release. These observations establish V0 as a crucial factor in vacuole fusion acting downstream of trans-SNARE pairing
PPARδ status and mismatch repair mediated neoplasia in the mouse intestine
BACKGROUND: Therapeutic regulation of PPARδ activity using selective agonists has been proposed for various disorders. However, the consequences of altered peroxisome proliferator-activated receptor delta (PPARδ) activity in the context of intestinal tumourigenesis remain somewhat unclear. Contradictory evidence suggesting PPARδ either attenuates or potentiates intestinal neoplasia. To further investigate the PPARδ dependency of intestinal tumourigenesis, we have analysed the consequences of PPARδ deficiency upon intestinal neoplasia occurring in mice with impaired mismatch DNA repair. METHODS: Mice deficient for both PPARδ and the mismatch repair gene Mlh1 were produced and the incidence and severity of intestinal neoplasia recorded. RESULTS: No significant differences between the control genotypes and the double mutant genotypes were recorded indicating that deficiency of PPARδ does not modify impaired mismatch repair induced neoplasia. CONCLUSION: In contrast with the previously observed acceleration of intestinal neoplasia in the context of the Apc(Min/+ )mouse, PPARδ deficiency does not alter the phenotype of mismatch repair deficiency. This data supports the notion that PPARδ is not required for adenoma formation and indicate that any pro-tumourigenic effect of PPARδ inactivation may be highly context dependent
Hospitality entrepreneurs managing quality of life and business growth
The hospitality industry is dominated by small- and medium-sized enterprises (SMEs).They are often led by entrepreneurs who face the challenge of simultaneously managing business decisions and their own wellbeing. The competitiveness of tourism destinations often depends on these entrepreneurs and therefore understanding their motivations and work patterns is critical. Research on individual wellbeing increasingly builds on the concept of quality of life (QoL). Hospitality and tourism literature so far predominantly focused on investigating QoL for tourists and residents, rather than for entrepreneurs’ QoL, even though being key stakeholders in the hospitality industry. Therefore, this study explores the factors influencing hospitality entrepreneurs’ quality of life (“HE-QoL”) and how these relate to business growth. Results of a 380 hospitality entrepreneurs’ survey identify six distinct factors of HE-QoL. Two groups of HE-QoL are identified with significant differences in fitness level activity, entrepreneurial competencies and business growth. Findings lead to recommendations to reduce stress to improve HE-QoL, and to develop entrepreneurial competencies, which help to cope with entrepreneurial challenges. Tourism destinations and politics can support hospitality entrepreneurs in these actions by creating conditions that foster social exchange in regional communities and trust in political and economic stability
Distinct Clinical and Laboratory Patterns of Pneumocystis jirovecii Pneumonia in Renal Transplant Recipients.
Late post-transplant Pneumocystis jirovecii pneumonia (PcP) has been reported in many renal transplant recipients (RTRs) centers using universal prophylaxis. Specific features of PcP compared to other respiratory infections in the same population are not well reported. We analyzed clinical, laboratory, administrative and radiological data of all confirmed PcP cases between January 2009 and December 2014. To identify factors specifically associated with PcP, we compared clinical and laboratory data of RTRs with non-PcP. Over the study period, 36 cases of PcP were identified. Respiratory distress was more frequent in PcP compared to non-PcP (tachypnea: 59%, 20/34 vs. 25%, 13/53, p = 0.0014; dyspnea: 70%, 23/33 vs. 44%, 24/55, p = 0.0181). In contrast, fever was less frequent in PcP compared to non-PcP pneumonia (35%, 11/31 vs. 76%, 42/55, p = 0.0002). In both cohorts, total lymphocyte count and serum sodium decreased, whereas lactate dehydrogenase (LDH) increased at diagnosis. Serum calcium increased in PcP and decreased in non-PcP. In most PcP cases (58%, 21/36), no formal indication for restart of PcP prophylaxis could be identified. Potential transmission encounters, suggestive of interhuman transmission, were found in 14/36, 39% of patients. Interhuman transmission seems to contribute importantly to PcP among RTRs. Hypercalcemia, but not elevated LDH, was associated with PcP when compared to non-PcP
The mycotoxin phomoxanthone A disturbs the form and function of the inner mitochondrial membrane.
Mitochondria are cellular organelles with crucial functions in the generation and distribution of ATP, the buffering of cytosolic Ca2+ and the initiation of apoptosis. Compounds that interfere with these functions are termed mitochondrial toxins, many of which are derived from microbes, such as antimycin A, oligomycin A, and ionomycin. Here, we identify the mycotoxin phomoxanthone A (PXA), derived from the endophytic fungus Phomopsis longicolla, as a mitochondrial toxin. We show that PXA elicits a strong release of Ca2+ from the mitochondria but not from the ER. In addition, PXA depolarises the mitochondria similarly to protonophoric uncouplers such as CCCP, yet unlike these, it does not increase but rather inhibits cellular respiration and electron transport chain activity. The respiration-dependent mitochondrial network structure rapidly collapses into fragments upon PXA treatment. Surprisingly, this fragmentation is independent from the canonical mitochondrial fission and fusion mediators DRP1 and OPA1, and exclusively affects the inner mitochondrial membrane, leading to cristae disruption, release of pro-apoptotic proteins, and apoptosis. Taken together, our results suggest that PXA is a mitochondrial toxin with a novel mode of action that might prove a useful tool for the study of mitochondrial ion homoeostasis and membrane dynamics
Modeling Policy and Agricultural Decisions in Afghanistan
Afghanistan is responsible for the majority of the world's supply of poppy
crops, which are often used to produce illegal narcotics like heroin. This
paper presents an agent-based model that simulates policy scenarios to
characterize how the production of poppy can be dampened and replaced with
licit crops over time. The model is initialized with spatial data, including
transportation network and satellite-derived land use data. Parameters
representing national subsidies, insurgent influence, and trafficking blockades
are varied to represent different conditions that might encourage or discourage
poppy agriculture. Our model shows that boundary-level interventions, such as
targeted trafficking blockades at border locations, are critical in reducing
the attractiveness of growing this illicit crop. The principle of least effort
implies that interventions decrease to a minimal non-regressive point, leading
to the prediction that increases in insurgency or other changes are likely to
lead to worsening conditions, and improvements require substantial jumps in
intervention resources.Comment: 16 pages, 5 figures; GeoJournal, 2012, 10.1007/s10708-012-9453-
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