6,203 research outputs found
Lipid biomarkers : Linking the utilization of frontal plankton biomass to enhanced condition of juvenile North Sea cod
Bacterial vaginosis and human immunodeficiency virus infection
Epidemiologic studies indicate that bacterial vaginosis (BV), a common alteration of lower genital tract flora in women, is associated with increased susceptibility to HIV infection. Other recent studies show that HIV is detected more frequently and at higher levels in the lower genital tract of HIV-seropositive women with BV. In vitro studies show that genital tract secretions from women with BV or flora associated with BV induce HIV expression in infected cells. The increased HIV expression appears to be due at least in part to activation through Toll-like receptors (TLR), specifically TLR2. Further research is needed to elucidate how BV contributes to HIV acquisition and transmission
Process Driven Software Engineering Environments
Software development organizations have begun using Software Engineering Environments (SEEs) with the goal of enhancing the productivity of software developers and improving the quality of software products. The encompassing nature of a SEE means that it is typically very tightly coupled with the way an organization does business. To be most effective, the components of a SEE must be well integrated and the SEE itself must be integrated with the organization.
The challenge of tool integration increases considerably when the components of the environment come from different vendors and support varying degrees of “openness”. The challenge of integration with the organization increases in a like manner when the environment must support a variety of different organizations over a long period of time. In addition to these pressures, any SEE must perform well and must “scale” well as the size of the organization changes.
This paper proposes basing the Software Engineering Environment on the software development process used in an organization in order to meet the challenges of integration, performance, and scaling. The goals and services of distributed operating systems and Software Engineering Environments are outlined in order to more clearly define their roles. The motivation for using a well defined software development process is established along with the benefits of basing the Software Engineering Environment on the software development process. Components of a SEE that could effectively support the process and provide integration, performance, and scaling benefits are introduced along with an outline of an Ada program used to model the proposed components. The conclusion provides strong support for process driven SEEs, encourages the expansion of the concept into other “environments,” and cautions against literal interpretations of “process integration” that may slow the acceptance of this powerful approach
Testing for HFE-related haemochromatosis
HFE-haemochromatosis is a genetic disorder resulting from mutations of the HFE gene. It primarily affects people of Northern European descent. Clinical manifestations result from the progressive deposition of iron into various organs including the liver. An elevated serum ferritin concentration greater than 300 microgram/L and a transferrin saturation of greater than 45% will identify almost all patients with HFE-haemochromatosis. HFE genotyping confirms the diagnosis. In some patients, liver biopsy may still be necessary as the degree of hepatic fibrosis has prognostic implications
Testing of High Voltage Surge Protection Devices for Use in Liquid Argon TPC Detectors
In this paper we demonstrate the capability of high voltage varistors and gas
discharge tube arrestors for use as surge protection devices in liquid argon
time projection chamber detectors. The insulating and clamping behavior of each
type of device is characterized in air (room temperature), and liquid argon
(90~K), and their robustness under high voltage and high energy surges in
cryogenic conditions is verified. The protection of vulnerable components in
liquid argon during a 150 kV high voltage discharge is also demonstrated. Each
device is tested for argon contamination and light emission effects, and both
are constrained to levels where no significant impact upon liquid argon time
projection chamber functionality is expected. Both devices investigated are
shown to be suitable for HV surge protection applications in cryogenic
detectors.Comment: 22 pages, 18 figures v2: reduced file size for journal submissio
The identification of mitochondrial DNA variants in glioblastoma multiforme
Background:
Mitochondrial DNA (mtDNA) encodes key proteins of the electron transfer chain (ETC), which produces ATP through oxidative phosphorylation (OXPHOS) and is essential for cells to perform specialised functions. Tumor-initiating cells use aerobic glycolysis, a combination of glycolysis and low levels of OXPHOS, to promote rapid cell proliferation and tumor growth. Glioblastoma multiforme (GBM) is an aggressively malignant brain tumor and mitochondria have been proposed to play a vital role in GBM tumorigenesis.
Results:
Using next generation sequencing and high resolution melt analysis, we identified a large number of mtDNA variants within coding and non-coding regions of GBM cell lines and predicted their disease-causing potential through in silico modeling. The frequency of variants was greatest in the D-loop and origin of light strand replication in non-coding regions. ND6 was the most susceptible coding gene to mutation whilst ND4 had the highest frequency of mutation. Both genes encode subunits of complex I of the ETC. These variants were not detected in unaffected brain samples and many have not been previously reported. Depletion of HSR-GBM1 cells to varying degrees of their mtDNA followed by transplantation into immunedeficient mice resulted in the repopulation of the same variants during tumorigenesis. Likewise, de novo variants identified in other GBM cell lines were also incorporated. Nevertheless, ND4 and ND6 were still the most affected genes. We confirmed the presence of these variants in high grade gliomas.
Conclusions:
These novel variants contribute to GBM by rendering the ETC. partially dysfunctional. This restricts metabolism to anaerobic glycolysis and promotes cell proliferation
Winter−spring transition in the subarctic Atlantic: microbial response to deep mixing and pre-bloom production
In temperate, subpolar and polar marine systems, the classical perception is that diatoms initiate the spring bloom and thereby mark the beginning of the productive season. Contrary to this view, we document an active microbial food web dominated by pico- and nanoplankton prior to the diatom bloom, a period with excess nutrients and deep convection of the water column. During repeated visits to stations in the deep Iceland and Norwegian basins and the shallow Shetland Shelf (26 March to 29 April 2012), we investigated the succession and dynamics of photosynthetic and heterotrophic microorganisms. We observed that the early phytoplankton production was followed by a decrease in the carbon:nitrogen ratio of the dissolved organic matter in the deep mixed stations, an increase in heterotrophic prokaryote (bacteria) abundance and activity (indicated by the high nucleic acid:low nucleic acid bacteria ratio), and an increase in abundance and size of heterotrophic protists. The major chl a contribution in the early winter-spring transition was found in the fraction 50 µm) were stimulated by deep mixing later in the period, while picophytoplankton were unaffected by mixing; both physical and biological reasons for this development are discussed herein
Construction and Assembly of the Wire Planes for the MicroBooNE Time Projection Chamber
In this paper we describe how the readout planes for the MicroBooNE Time
Projection Chamber were constructed, assembled and installed. We present the
individual wire preparation using semi-automatic winding machines and the
assembly of wire carrier boards. The details of the wire installation on the
detector frame and the tensioning of the wires are given. A strict quality
assurance plan ensured the integrity of the readout planes. The different tests
performed at all stages of construction and installation provided crucial
information to achieve the successful realisation of the MicroBooNE wire
planes.Comment: 24 pages, 22 figures, accepted for publication as Technical Report in
JINS
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