560 research outputs found
Prevalence of liver fluke (Fasciola hepatica) in wild Red Deer (Cervus elaphus): coproantigen ELISA is a practicable alternative to faecal egg counting for surveillance in remote populations
Red deer (Cervus elaphus) are hosts of liver fluke (Fasciola hepatica); yet, prevalence is rarely quantified in wild populations. Testing fresh samples from remote regions by faecal examination (FE) can be logistically challenging; hence, we appraise frozen storage and the use of a coproantigen ELISA (cELISA) for F. hepatica surveillance. We also present cELISA surveillance data for red deer from the Highlands of Scotland. Diagnoses in faecal samples (207 frozen, 146 fresh) were compared using a cELISA and by FE. For each storage method (frozen or fresh), agreement between the two diagnostics was estimated at individual and population levels, where population prevalence was stratified into cohorts (e.g., by sampling location). To approximate sensitivity and specificity, 65 post-slaughter whole liver examinations were used as a reference. At the individual level, FE and cELISA diagnoses agreed moderately (κfrozen = 0.46; κfresh = 0.51), a likely reflection of their underlying principles. At the population level, FE and cELISA cohort prevalence correlated strongly (Pearson’s R = 0.89, p < 0.0001), reflecting good agreement on relative differences between cohort prevalence. In frozen samples, prevalence by cELISA exceeded FE overall (42.8% vs. 25.8%) and in 9/12 cohorts, alluding to differences in sensitivity; though, in fresh samples, no significant difference was found. In 959 deer tested by cELISA across the Scottish Highlands, infection prevalence ranged from 9.6% to 53% by sampling location. We highlight two key advantages of cELISA over FE: i) the ability to store samples long term (frozen) without apparent loss in diagnostic power; and ii) reduced labour and the ability to process large batches. Further evaluation of cELISA sensitivity in red deer, where a range of fluke burdens can be obtained, is desirable. In the interim, the cELISA is a practicable diagnostic for F. hepatica surveillance in red deer, and its application here has revealed considerable geographic, temporal, sex and age related differences in F. hepatica prevalence in wild Scottish Highland red deer
Development and application of a novel and compact long-wavelength fluorescence spectrometer
Long wavelength (>600nm) fluorescence offers many advantages when applied to analysis,
including minimal autofluorescence and scattered light from biological samples and the
possibility of compact, robust, yet sensitive instruments. Modern clinical analysis has a
number of specific requirements, namely specificity, sensitivity and speed, whilst the ability
to monitor samples away from the laboratory is increasingly in demand. Immunoassays
possess all these attributes and can be used in the following: environmental monitoring; clinical analysis; therapeutic drug monitoring.
This research work describes a novel portable fluorescence spectrophotometer using long
wavelength detection which can be used in all environments
Impact of Gravel Dredging Operations on Surface Water Quality in Streams in the Upper Cumberland Basin
This is a report to the USEPA, Kentucky Division of Water and the Kentucky Water Resources Research Institute, focused on the biologic and morphological impacts of gravel mining in the upper Cumberland basin
Analytic Metaphysics versus Naturalized Metaphysics: The Relevance of Applied Ontology
The relevance of analytic metaphysics has come under criticism: Ladyman & Ross, for instance, have suggested do discontinue the field. French & McKenzie have argued in defense of analytic metaphysics that it develops tools that could turn out to be useful for philosophy of physics. In this article, we show first that this heuristic defense of metaphysics can be extended to the scientific field of applied ontology, which uses constructs from analytic metaphysics. Second, we elaborate on a parallel by French & McKenzie between mathematics and metaphysics to show that the whole field of analytic metaphysics, being useful not only for philosophy but also for science, should continue to exist as a largely autonomous field
A new long-wavelength fluorigenic substrate for alkaline phosphatase: synthesis and characterisation
Naphthofluorescein diphosphate has been synthesised from
the parent dye, and shown to be an attractive longwavelength
alternative to other fluorigenic substrates for the
determination of alkaline phosphatase. Its application to the
determination of theophylline, an inhibitor of this enzyme,
has been demonstrated. The optimum excitation wavelength
of the hydrolysis product naphthofluorescein has been found
to depend on the presence of additives such as cyclodextrins
and (3-[3-cholamidopropyl]-dimethylamino)-1-propane sulfonate
(CHAPS): such effects can be used to raise the
excitation wavelength to match the output of a 635 nm diode
laser in a simple and sensitive fluorescence detector
A new long-wavelength fluorigenic substrate for alkaline phosphatase: synthesis and characterisation
Microclusters of inhibitory killer immunoglobulin–like receptor signaling at natural killer cell immunological synapses
We report the supramolecular organization of killer Ig–like receptor (KIR) phosphorylation using a technique applicable to imaging phosphorylation of any green fluorescent protein–tagged receptor at an intercellular contact or immune synapse. Specifically, we use fluorescence lifetime imaging (FLIM) to report Förster resonance energy transfer (FRET) between GFP-tagged KIR2DL1 and a Cy3-tagged generic anti-phosphotyrosine monoclonal antibody. Visualization of KIR phosphorylation in natural killer (NK) cells contacting target cells expressing cognate major histocompatibility complex class I proteins revealed that inhibitory signaling is spatially restricted to the immune synapse. This explains how NK cells respond appropriately when simultaneously surveying susceptible and resistant target cells. More surprising, phosphorylated KIR was confined to microclusters within the aggregate of KIR, contrary to an expected homogeneous distribution of KIR signaling across the immune synapse. Also, yellow fluorescent protein–tagged Lck, a kinase important for KIR phosphorylation, accumulated in a multifocal distribution at inhibitory synapses. Spatial confinement of receptor phosphorylation within the immune synapse may be critical to how activating and inhibitory signals are integrated in NK cells
Directed flow of antiprotons in Au+Au collisions at AGS
Directed flow of antiprotons is studied in Au+Au collisions at a beam
momentum of 11.5A GeV/c. It is shown that antiproton directed flow is
anti-correlated to proton flow. The measured transverse momentum dependence of
the antiproton flow is compared with predictions of the RQMD event generator.Comment: 16 pages, 6 figure
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