192 research outputs found
Evaluation und Vergleich von zwei immunchromatographischen Kassetten - Triple Tests fĂŒr die zeitgleiche Detektion von Cryptosporidium spp.; Giardia lamblia und Entamoeba histolytica / Entamoeba dispar Antigenen in humanen Stuhlproben
Der Einsatz von immunchromatographischen Schnelltests in der Med. Parasitologie, zusĂ€tzlich zur mikroskopischen Diagnostik, stellt eine einfache, schnelle und sichere Methode fĂŒr die gleichzeitige Erkennung von Giardia lamblia, E. histolytica/dispar und Cryptosporidium parvum â spezifischen Antigenen in unfixierten Stuhlproben humanen Ursprungs dar. In der vorliegenden Untersuchung erfolgte eine vergleichende, methodische Validierung der Schnelltestsysteme des RIDAÂź Quick Cryptosporidium/Giardia/Entamoeba combi der Firma R-Biopharm und des TriageÂź Micro Parasite Panel der Firma BIOSITE Diagnostics im Hinblick auf den Gebrauch in den mikrobiologischen Einsatzlaboratorien der Bundeswehr. Neben SensitivitĂ€t und SpezifitĂ€t wurden auch Parameter wie Handhabung, Kosten, Haltbarkeit und PraktikabilitĂ€t unter besonderen Bedingungen bewertet
The InfraâRed Absorption Spectrum of Methyl Alcohol
Using a grating spectrometer having a KBr foreprism the spectrum of methyl alcohol vapor was studied in the region from 2.5 to 26ÎŒ. This molecule has bands at 3683, 2978, 2845, 2054, 1477, 1455, 1340, 1034.18 cmâ1 and a very broad band extending from 860 to beyond 380 cmâ1. These bands are typical perpendicular and parallel bands and indicate that the molecule is only slightly asymmetric.From the fine structure of the 1034.18 cmâ1 parallel band and from certain assumptions about the structure of the molecule the two largest moments of inertia, A and B, were found to be 35.18 and 33.83Ă10â40 g cm2, respectively. It was not possible to measure C directly but it was estimated to be approximately 6.8Ă10â40 g cm2.The low frequency band is probably due to the vibration of the hydroxyl hydrogen atom perpendicular to the OâH bond and perpendicular to the figure axis of the molecule. The presence of this band indicates that the hydroxyl group is not free to rotate, at least in the ground state. There is evidence of rotation in the structure of the band near the high frequency edge. The spacing increases toward high frequencies and finally there is a group of lines having a spacing of about 40 cmâ1 between 600 and 860 cmâ1. Since these lines are very weak and occur at such high frequencies it appears that free rotation exists only in states of high excitation. A quantitative study of free rotation in a symmetric molecule has been made. This investigation indicates that in a first approximation free rotation should give rise to groups of lines having a spacing of about 40 cmâ1 between each group.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70345/2/JCPSA6-6-9-553-1.pd
Fluorometabolite biosynthesis : isotopically labelled glycerol incorporations into the antibiotic nucleocidin in Streptomyces calvus
Deuterium and carbon-13 labelled glycerols have been fed to Streptomyces calvus fermentations and isotope incorporation into the fluorine containing antibiotic nucleocidin have been evaluated by 19F-NMR. A single deuterium atom was incorporated from [2H5]- and (R)-[2H2]- glycerol into C-5â of the antibiotic, suggesting that an oxidation occurs at this carbon after ribose ring assembly from glycerol (pentose phosphate pathway), during nucleocidin biosynthesis.PostprintPostprintPeer reviewe
Phase synchronization from noisy univariate signals
We present methods for detecting phase synchronization of two
unidirectionally coupled, self-sustained noisy oscillators from a signal of the
driven oscillator alone. One method detects soft, another hard phase locking.
Both are applied to the problem of detecting phase synchronization in von
Karman vortex flow meters.Comment: 4 pages, 4 figure
The InfraâRed Absorption Spectrum of Propane
Of the twentyâseven internal degrees of freedom of propane, all nondegenerate, twentyâtwo may appear as fundamental absorption bands. These bands fall into three symmetry classes, designated A1, B1 and B2, and distinguishable by their characteristic contours. Because of overlapping, however, it is impossible in many cases to determine their positions precisely. This is especially true in the regions of the CâH valence and deformation frequencies. Some ten or twelve fundamental bands may be identified with confidence as well as a number of combinations. An A1 band at 870 cmâ1 and a B2 band at 748 cmâ1 have been partially resolved, the line spacing being about 1.47 cmâ1 in agreement with predictions based upon electron diffraction measurements. The fine structure of the B1 bands has not been observed (the predicted spacing is 0.5 cmâ1) but the interval between maxima of the P and R branches is approximately 26 cmâ1 as expected. With 24 cmâatmospheres of gas no bands were observed between 15ÎŒ and 35ÎŒ, although the symmetrical CâC deformation might be expected to produce a band of appreciable intensity within these limits. This frequency has apparently been observed in Raman spectra at 375 cmâ1.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70815/2/JCPSA6-9-7-487-1.pd
A near real-time water surface detection method based on HSV transformation of MODIS multi-Spectral time series data
In the face of global population growth and the uneven distribution of water supply, a better knowledge of the spatial and temporal distribution of surface water resources is critical. Remote sensing provides a synoptic view of ongoing processes, which addresses the intricate nature of water surfaces and allows an assessment of the pressures placed on aquatic ecosystems. However, the main challenge in identifying water surfaces from remotely sensed data is the high variability of spectral signatures, both in space and time. In the last 10 years only a few operational methods have been proposed to map or monitor surface water at continental or global scale, and each of them show limitations. The objective of this study is to develop and demonstrate the adequacy of a generic multi-temporal and multi-spectral image analysis method to detect water surfaces automatically, and to monitor them in near-real-time. The proposed approach, based on a transformation of the RGB color space into HSV, provides dynamic information at the continental scale. The validation of the algorithm showed very few omission errors and no commission errors. It demonstrates the ability of the proposed algorithm to perform as effectively as human interpretation of the images. The validation of the permanent water surface product with an independent dataset derived from high resolution imagery, showed an accuracy of 91.5% and few commission errors. Potential applications of the proposed method have been identified and discussed. The methodology that has been developed 27 is generic: it can be applied to sensors with similar bands with good reliability, and minimal effort. Moreover, this experiment at continental scale showed that the methodology is efficient for a large range of environmental conditions. Additional preliminary tests over other continents indicate that the proposed methodology could also be applied at the global scale without too many difficultie
High potential for weathering and climate effects of non-vascular vegetation in the Late Ordovician
It has been hypothesized that predecessors of todayâs bryophytes significantly increased global chemical weathering in the Late Ordovician, thus reducing atmospheric CO2 concentration and contributing to climate cooling and an interval of glaciations. Studies that try to quantify the enhancement of weathering by non-vascular vegetation, however, are usually limited to small areas and low numbers of species, which hampers extrapolating to the global scale and to past climatic conditions. Here we present a spatially explicit modelling approach to simulate global weathering by non-vascular vegetation in the Late Ordovician. We estimate a potential global weathering flux of 2.8 (km3 rock) yrâ1, defined here as volume of primary minerals affected by chemical transformation. This is around three times larger than todayâs global chemical weathering flux. Moreover, we find that simulated weathering is highly sensitive to atmospheric CO2 concentration. This implies a strong negative feedback between weathering by non-vascular vegetation and Ordovician climate
Effects of habitat and land use on breeding season density of male Asian Houbara Chlamydotis macqueenii
Landscape-scale habitat and land-use influences on Asian Houbara Chlamydotis macqueenii (IUCN Vulnerable) remain unstudied, while estimating numbers of this cryptic, low-density, over-hunted species is challenging. In spring 2013, male houbara were recorded at 231 point counts, conducted twice, across a gradient of sheep density and shrub assemblages within 14,300 kmÂČ of the Kyzylkum Desert, Uzbekistan. Four sets of models related male abundance to: (1) vegetation structure (shrub height and substrate); (2) shrub assemblage; (3) shrub species composition (multidimensional scaling); (4) remote-sensed derived land-cover (GLOBCOVER, 4 variables). Each set also incorporated measures of landscape rugosity and sheep density. For each set, multi-model inference was applied to generalised linear mixed models of visit-specific counts that included important detectability covariates and point ID as a random effect. Vegetation structure received strongest support, followed by shrub species composition and shrub assemblage, with weakest support for the GLOBCOVER model set. Male houbara numbers were greater with lower mean shrub height, more gravel and flatter surfaces, but were unaffected by sheep density. Male density (mean 0.14 km-2, 95% CI, 0.12â0.15) estimated by distance analysis differed substantially among shrub assemblages, being highest in vegetation dominated by Salsola rigida (0.22 [CI, 0.20â0.25]), high in areas of S. arbuscula and Astragalus (0.14 [CI, 0.13â0.16] and 0.15 [CI, 0.14â0.17] respectively), lower (0.09 [CI, 0.08â0.10]) in Artemisia and lowest (0.04 [CI, 0.04â0.05]) in Calligonum. The study area was estimated to hold 1,824 males (CI: 1,645â2,030). The spatial distribution of relative male houbara abundance, predicted from vegetation structure models, had the strongest correspondence with observed numbers in both model-calibration and the subsequent yearâs data. We found no effect of pastoralism on male distribution but potential effects on nesting females are unknown. Density differences among shrub communities suggest extrapolation to estimate country- or range-wide population size must take account of vegetation composition
Long-term decline of the Amazon carbon sink
Atmospheric carbon dioxide records indicate that the land surface has acted as a strong global carbon sink over recent decades1, 2, with a substantial fraction of this sink probably located in the tropics3, particularly in the Amazon4. Nevertheless, it is unclear how the terrestrial carbon sink will evolve as climate and atmospheric composition continue to change. Here we analyse the historical evolution of the biomass dynamics of the Amazon rainforest over three decades using a distributed network of 321 plots. While this analysis confirms that Amazon forests have acted as a long-term net biomass sink, we find a long-term decreasing trend of carbon accumulation. Rates of net increase in above-ground biomass declined by one-third during the past decade compared to the 1990s. This is a consequence of growth rate increases levelling off recently, while biomass mortality persistently increased throughout, leading to a shortening of carbon residence times. Potential drivers for the mortality increase include greater climate variability, and feedbacks of faster growth on mortality, resulting in shortened tree longevity5. The observed decline of the Amazon sink diverges markedly from the recent increase in terrestrial carbon uptake at the global scale1, 2, and is contrary to expectations based on models6
An update on molecular cat allergens: Fel d 1 and what else? Chapter 1: Fel d 1, the major cat allergen
Background: Cats are the major source of indoor inhalant allergens after house dust mites. The global incidence of cat allergies is rising sharply, posing a major public health problem. Ten cat allergens have been identified. The major allergen responsible for symptoms is Fel d 1, a secretoglobin and not a lipocalin, making the cat a special case among mammals.
Main body: Given its clinical predominance, it is essential to have a good knowledge of this allergenic fraction, including its basic structure, to understand the new exciting diagnostic and therapeutic applications currently in development. The recent arrival of the component-resolved diagnosis, which uses molecular allergens, represents a unique opportunity to improve our understanding of the disease. Recombinant Fel d 1 is now available for in vitro diagnosis by the anti-Fel d 1 specific IgE assay. The first part of the review will seek to describe the recent advances related to Fel d 1 in terms of positive diagnosis and assessment of disease severity. In daily practice, anti-Fel d 1 IgE tend to replace those directed against the overall extract but is this attitude justified? We will look at the most recent arguments to try to answer this question. In parallel, a second revolution is taking place thanks to molecular engineering, which has allowed the development of various forms of recombinant Fel d 1 and which seeks to modify the immunomodulatory properties of the molecule and thus the clinical history of the disease via various modalities of anti-Fel d 1-specific immunotherapy. We will endeavor to give a clear and practical overview of all these trends
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