2,726 research outputs found
Development of a polyclonal competitive enzyme-linked immunosorbent assay for detection of antibodies to Ehrlichia ruminantium
A polyclonal competitive enzyme-linked immunosorbent assay (PC-ELISA) is described for detection of antibodies to Ehrlichia (Cowdria) ruminantium by using a soluble extract of endothelial cell culture-derived E. ruminantium as the antigen and biotin-labeled polyclonal goat immunoglobulins as the competitor. For goats, the diagnostic sensitivity and specificity were both 100% with a cutoff of 80% inhibition (80 PI), with detection of antibodies for 550 days postinfection. For cattle, diagnostic sensitivity and specificity were 86 and 100%, respectively, with a cutoff of 50 PI and 79 and 100% with a cutoff of 70 PI. Cross-reactions with high-titer experimental or field antisera to other Ehrlichia and Anaplasma species were observed at up to 68 PI in cattle and up to 85 PI in sheep, and therefore to exclude these cross-reactions, cutoffs of 70 PI for bovine serology and 85 PI for small-ruminant serology were selected. Application of the PC-ELISA to bovine field sera from South Africa gave a higher proportion of positive results than application of the murine macrophage immunofluorescent antibody test or indirect ELISA, suggesting a better sensitivity for detection of recovered cattle, and results with bovine field sera from Malawi were consistent with the observed endemic state of heartwater and the level of tick control practiced at the sample sites. Reproducibility was high, with average standard deviations intraplate of 1.2 PI and interplate of 0.6 PI. The test format is simple, and the test is economical to perform and has a level of sensitivity for detection of low-titer positive bovine sera that may prove to be of value in epidemiological studies on heartwater
Growth of Cowdria ruminantium, the causative agent of heartwater, in a tick cell line
The tick-borne rickettsia Cowdria ruminantium has been propagated continuously for over 500 days in the Ixodes scapularis tick cell line IDE8 by using the Gardel isolate from bovine endothelial cells as an inoculum. Infection of the tick cells was confirmed by PCR, karyotyping, electron microscopy, and reinfection of bovine cells
Zoning for local heat and energy efficiency strategies
Any plan to decarbonise heat will need plenty of input from those familiar with Scotland’s diverse urban, rural and social geography. The Scottish Government is helping local authorities pilot an ambitious approach to local heat planning which, if done right, could provide the blueprint for low-carbon heat industries to flourish. So how are these plans shaping up, what benefits might they provide and will they really work for the industry
A comparison of AC and HVDC options for the connection of offshore wind generation in Great Britain
This paper presents a comparison of two forms of cable connection of a distant offshore wind farm to a transmission system: AC and HVDC. The requirements of relevant industry standards in Great Britain (GB) that drive a connection design and, hence, its cost are highlighted along with an analysis of the ways in which AC cable connections might be made to comply while facilitating export of active power. Dynamic studies investigating responses to grid-side short circuit faults show that, in the particular scenarios studied, an AC connection of a wind farm in the place of a large synchronous generator is marginally detrimental while an HVDC connection is beneficial. A comparison of costs shows that the cross-over distance at which HVDC is cheaper than AC for wind farms of different sizes occurs at longer distances than have hitherto commonly been assumed, and AC connections benefit from reactive compensation not only at the point of common coupling and wind farm end but also at the connection mid-point
Infection with Chlamydia Pneumoniae Alters Calcium-associated Gene Regulation and Processes in Neuronal Cells and Monocytes: Implications for Alzheimer’s Disease
Background: First proposed by Khachaturian in 1994, the calcium hypothesis postulates that sustained disturbance of intracellular calcium is the leading cause of neurodegenerative disorders. Studies showing alteration in calcium signaling in both sporadic and familial Alzheimer’s disease (AD) support this hypothesis. Intracellular calcium signaling is tightly regulated in time, intensity, and space, and is responsible for a variety of neuronal functions. Calcium influx from the extracellular environment modulates calcium levels, as do intracellular stores in the endoplasmic reticulum. The focus of this study was to test various calcium related genes in both monocytes and neuronal cells. Previous studies have shown that cells infected with Chlamydia pneumoniae (Cpn) exhibit altered protein processing, such as amyloid and tau modification, consistent with those found in AD. We expect to see significant alterations in calcium genes, as well as their protein products in Cpn infected cells. Every calcium gene has a unique function in the cell. Determining which genes are up or down regulated following infection may provide insight into how the neurodegeneration process observed in AD is initiated by Cpn infections
Further studies on relic neutrino asymmetry generation II: a rigorous treatment of repopulation in the adiabatic limit
We derive an approximate relic neutrino asymmetry evolution equation that
systematically incorporates repopulation processes from the full quantum
kinetic equations (QKEs). It is shown that in the collision dominant epoch, the
said equation reduces precisely to the expression obtained previously from the
static/adiabatic approximation. The present treatment thus provides a rigorous
justification for the seemingly incongruous assumptions of a negligible
repopulation function and instantaneous repopulation sometimes employed in
earlier works.Comment: RevTeX, 11 pages, no figure
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Cost analysis of noninvasive blood-based microRNA testing versus CT scans for follow-up in patients with testicular germ-cell tumors
BACKGROUND: Our group has developed a noninvasive blood-based microRNA (miRNA) test for improving diagnosis, disease monitoring, and relapse detection in malignant testicular germ-cell tumors (TGCTs). Performance analysis suggests the test is likely to have comparable sensitivity and specificity in detecting TGCT as computed tomography (CT), thus reducing the need for serial CT scans for follow-up monitoring, with associated reductions in cumulative radiation burden and second cancer risk. To facilitate clinical adoption, we undertook a cost analysis to identify the budget impact of replacing CT scans with miRNA testing within health care systems. METHODS: The TGCT aftercare pathway was mapped out using National Comprehensive Cancer Network guidelines. A Markov model was built to simulate the impact of the miRNA test on TGCT aftercare costs. Incidence, treatment probabilities, relapse rate, and death rate data were collected from published studies to populate the model. RESULTS: Applying our model to the US health care system, the miRNA test has the potential to save up to $69 million per year in aftercare expenses related to TGCT treatment, with exact savings depending on the adoption rate and test price. CONCLUSION: This analysis demonstrates the potential positive budget impact of adopting miRNA testing in place of CT scans in the clinical management of TGCTs
Meeting the ISTE Challenge in the Field: An Overview of the First Six Distinguished Achievement Award Winning Programs
The 2002 National Educational Technology Standards (NETS) Distinguished Achievement Awards, sponsored by the International Society for Technology in Education (ISTE), were awarded to six teacher education programs across the United States. The awards recognize institutions that exemplify successful integration of the National Educational Technology Standards for Teachers (NETS[solid dot]T) into teacher education programs. Institutions across the country completed an extensive application process to be selected one of the first six recipients of the ISTE Distinguished Achievement award. This process included online documentation that demonstrated the program\u27s implementation of the NETS[solid dot]T models and practices. This article provides a means of uniting various programs and program developers (teacher educators and instructional technologists) by looking at the most common obstacles they face in the pursuit of appropriate infusion of technology into teacher education programs and workable solutions for overcoming those obstacles
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