Serological diagnosis of brucellosis in goats: comparison of techniques

Goat production is an important item in the agricultural system of Argentina and brucellosis caused by Brucella melitensis is considered the main cause reproductive problems in this species. Although definitive diagnosis for this disease is made by isolation of the etiologic agent, but in practice the health status of a herd was evaluated by serological techniques indirect testing. To evaluate and compare the performance of different serological tests for diagnosis of brucellosis in goats, serum samples were analyzed. The following tests were performed: buffered plate antigen (BPA), rose bengal (RB RB 3% and 8%), fluorescence polarization (FPA) and the test tube and 2-mercaptoethanol (SAT/2ME). The validity of each test was determined in a relative manner by combination of indirect ELISA (IELISA) and complement fixation (CF). BPA was the most sensitive test, followed by SAT/2ME, 3% RB, FPA and, finally, RB 8%. FPA test, when used in series with BPA, significantly improved overall specificity. Based on these results it was proposed for brucellosis diagnosis in goats, BPA as a screening test, FPA as complementary test, and FC and IELISA as confirmatory tests. SAT/2ME is recommended only when it is not possible to perform other tests, due to the toxic effects of SAT/2ME reagents.Fil: Cisterna, C. Comisión de Investigaciones Científicas (CIC). Buenos Aires, ArgentinaFil: Conde, S. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Patobiología. Buenos Aires, ArgentinaFil: Hollender, D. CONICET. ArgentinaFil: Martino, P.E. Comisión de Investigaciones Científicas (CIC). Buenos Aires, ArgentinaFil: Samartino L. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Patobiología. Buenos Aires, ArgentinaLa producción caprina representa un rubro importante dentro del sistema agropecuario de la República Argentina y la brucelosis causada por Brucella melitensis es considerada el motivo principal de los problemas reproductivos en esta especie. El diagnóstico de certeza se realiza aislando el agente etiológico, aunque en la práctica se evalúa el estado sanitario de un hato mediante pruebas serológicas. El objetivo de este trabajo fue evaluar y comparar el desempeño de las distintas pruebas serológicas tamíz y complementarias para el diagnóstico de la brucelosis caprina. Para ello, se analizaron muestras de suero de animales sin vacunación, realizando antígeno buferado en placa (BPA), rosa de bengala (RB 3 % y RB 8 %), polarización fluorescente (FPA) y pruebas de tubo y 2 mercaptoetanol (SAT/2ME). La validez de cada prueba se determinó por combinación de ELISA Indirecto (IELISA) y Fijación de Complemento (FC). BPA resultó ser más sensible, seguido de SAT/2ME, RB 3%, FPA y por último RB 8%. Al realizar FPA en serie con BPA mejoró significativamente la especificidad global. Se propone BPA como prueba tamíz, FPA como complementaria y FC e IELISA como confirmatorias. Se recomienda SAT/2ME sólo en los casos en que no sea posible la realización de las otras pruebas debido a los efectos tóxicos de los reactivos empleados para su realización

Diagnóstico serológico de brucelosis en caprinos: comparación de técnicas

La producción caprina representa un rubro importante dentro del sistema agropecuario de la República Argentina y la brucelosis causada por Brucella melitensis es considerada el motivo principal de los problemas reproductivos en esta especie. El diagnóstico de certeza se realiza aislando el agente etiológico, aunque en la práctica se evalúa el estado sanitario de un hato mediante pruebas serológicas. El objetivo de este trabajo fue evaluar y comparar el desempeño de las distintas pruebas serológicas tamíz y complementarias para el diagnóstico de la brucelosis caprina. Para ello, se analizaron muestras de suero de animales sin vacunación, realizando antígeno buferado en placa (BPA), rosa de bengala (RB 3 % y RB 8 %), polarización fluorescente (FPA) y pruebas de tubo y 2 mercaptoetanol (SAT/2ME). La validez de cada prueba se determinó por combinación de ELISA Indirecto (IELISA) y Fijación de Complemento (FC). BPA resultó ser más sensible, seguido de SAT/2ME, RB 3%, FPA y por último RB 8%. Al realizar FPA en serie con BPA mejoró significativamente la especificidad global. Se propone BPA como prueba tamíz, FPA como complementaria y FC e IELISA como confirmatorias. Se recomienda SAT/2ME sólo en los casos en que no sea posible la realización de las otras pruebas debido a los efectos tóxicos de los reactivos empleados para su realización.Goat production is an important item in the agricultural system of Argentina and brucellosis caused by Brucella melitensis is considered the main cause reproductive problems in this species. Although definitive diagnosis for this disease is made by isolation of the etiologic agent, but in practice the health status of a herd was evaluated by serological techniques indirect testing. To evaluate and compare the performance of different serological tests for diagnosis of brucellosis in goats, serum samples were analyzed. The following tests were performed: buffered plate antigen (BPA), rose bengal (RB RB 3% and 8%), fluorescence polarization (FPA) and the test tube and 2-mercaptoethanol (SAT/2ME). The validity of each test was determined in a relative manner by combination of indirect ELISA (IELISA) and complement fixation (CF). BPA was the most sensitive test, followed by SAT/2ME, 3% RB, FPA and, finally, RB 8%. FPA test, when used in series with BPA, significantly improved overall specificity. Based on these results it was proposed for brucellosis diagnosis in goats, BPA as a screening test, FPA as complementary test, and FC and IELISA as confirmatory tests. SAT/2ME is recommended only when it is not possible to perform other tests, due to the toxic effects of SAT/2ME reagents

Topological representations of matroid maps

The Topological Representation Theorem for (oriented) matroids states that every (oriented) matroid can be realized as the intersection lattice of an arrangement of codimension one homotopy spheres on a homotopy sphere. In this paper, we use a construction of Engstr\"om to show that structure-preserving maps between matroids induce topological mappings between their representations; a result previously known only in the oriented case. Specifically, we show that weak maps induce continuous maps and that the process is a functor from the category of matroids with weak maps to the homotopy category of topological spaces. We also give a new and conceptual proof of a result regarding the Whitney numbers of the first kind of a matroid.Comment: Final version, 21 pages, 8 figures; Journal of Algebraic Combinatorics, 201

Do contaminants originating from state-of-the-art treated wastewater impact the ecological quality of surface waters?

Since the 1980s, advances in wastewater treatment technology have led to considerably improved surface water quality in the urban areas of many high income countries. However, trace concentrations of organic wastewater-associated contaminants may still pose a key environmental hazard impairing the ecological quality of surface waters. To identify key impact factors, we analyzed the effects of a wide range of anthropogenic and environmental variables on the aquatic macroinvertebrate community. We assessed ecological water quality at 26 sampling sites in four urban German lowland river systems with a 0–100% load of state-of-the-art biological activated sludge treated wastewater. The chemical analysis suite comprised 12 organic contaminants (five phosphor organic flame retardants, two musk fragrances, bisphenol A, nonylphenol, octylphenol, diethyltoluamide, terbutryn), 16 polycyclic aromatic hydrocarbons, and 12 heavy metals. Non-metric multidimensional scaling identified organic contaminants that are mainly wastewater-associated (i.e., phosphor organic flame retardants, musk fragrances, and diethyltoluamide) as a major impact variable on macroinvertebrate species composition. The structural degradation of streams was also identified as a significant factor. Multiple linear regression models revealed a significant impact of organic contaminants on invertebrate populations, in particular on Ephemeroptera, Plecoptera, and Trichoptera species. Spearman rank correlation analyses confirmed wastewater-associated organic contaminants as the most significant variable negatively impacting the biodiversity of sensitive macroinvertebrate species. In addition to increased aquatic pollution with organic contaminants, a greater wastewater fraction was accompanied by a slight decrease in oxygen concentration and an increase in salinity. This study highlights the importance of reducing the wastewater-associated impact on surface waters. For aquatic ecosystems in urban areas this would lead to: (i) improvement of the ecological integrity, (ii) reduction of biodiversity loss, and (iii) faster achievement of objectives of legislative requirements, e.g., the European Water Framework Directive

Discrete approximations for complex Kac-Moody groups

We construct a map from the classifying space of a discrete Kac-Moody group over the algebraic closure of the field with p elements to the classifying space of a complex topological Kac-Moody group and prove that it is a homology equivalence at primes q different from p. This generalises a classical result of Quillen-Friedlander-Mislin for Lie groups. As an application, we construct unstable Adams operations for general Kac-Moody groups compatible with the Frobenius homomorphism. In contrast to the Lie case, the homotopy fixed points of these unstable Adams operations cannot be realized at q as the classifying spaces of Kac-Moody groups over finite fields. Our results rely on new integral homology decompositions for certain infinite dimensional unipotent subgroups of discrete Kac-Moody groups.Comment: New title and revised introduction, references added; results and proofs unchanged, 31 pages, 1 figur

Derivation of consistent hard rock (1000<Vs<3000 m/s) GMPEs from surface and down-hole recordings: Analysis of KiK-net data

A key component in seismic hazard assessment is the estimation of ground motion for hard rock sites, either for applications to installations built on this site category, or as an input motion for site response computation. Empirical ground motion prediction equations (GMPEs) are the traditional basis for estimating ground motion while VS30 is the basis to account for site conditions. As current GMPEs are poorly constrained for VS30 larger than 1000 m/s, the presently used approach for estimating hazard on hard rock sites consists of “host-to-target” adjustment techniques based on VS30 and κ0 values. The present study investigates alternative methods on the basis of a KiK-net dataset corresponding to stiff and rocky sites with 500 < VS30 < 1350 m/s. The existence of sensor pairs (one at the surface and one in depth) and the availability of P- and S-wave velocity profiles allow deriving two “virtual” datasets associated to outcropping hard rock sites with VS in the range [1000, 3000] m/s with two independent corrections: 1/down-hole recordings modified from within motion to outcropping motion with a depth correction factor, 2/surface recordings deconvolved from their specific site response derived through 1D simulation. GMPEs with simple functional forms are then developed, including a VS30 site term. They lead to consistent and robust hard-rock motion estimates, which prove to be significantly lower than host-to-target adjustment predictions. The difference can reach a factor up to 3–4 beyond 5 Hz for very hard-rock, but decreases for decreasing frequency until vanishing below 2 Hz

Understanding single-station ground motion variability and uncertainty (sigma) – Lessons learnt from EUROSEISTEST

Accelerometric data from the well-studied valley EUROSEISTEST are used to investigate ground motion uncertainty and variability. We define a simple local ground motion prediction equation (GMPE) and investigate changes in standard deviation (σ) and its components, the between-event variability (τ) and within-event variability (φ). Improving seismological metadata significantly reduces τ (30-50%), which in turn reduces the total σ. Improving site information reduces the systematic site-to-site variability, φS2S (20-30%), in turn reducing φ, and ultimately, σ. Our values of standard deviations are lower than global values from literature, and closer to path-specific than site-specific values. However, our data have insufficient azimuthal coverage for single-path analysis. Certain stations have higher ground-motion variability, possibly due to topography, basin edge or downgoing wave effects. Sensitivity checks show that 3 recordings per event is a sufficient data selection criterion, however, one of the dataset’s advantages is the large number of recordings per station (9-90) that yields good site term estimates. We examine uncertainty components binning our data with magnitude from 0.01 to 2 s; at smaller magnitudes, τ decreases and φSS increases, possibly due to κ and source-site trade-offs Finally, we investigate the alternative approach of computing φSS using existing GMPEs instead of creating an ad hoc local GMPE. This is important where data are insufficient to create one, or when site-specific PSHA is performed. We show that global GMPEs may still capture φSS, provided that: 1. the magnitude scaling errors are accommodated by the event terms; 2. there are no distance scaling errors (use of a regionally applicable model). Site terms (φS2S) computed by different global GMPEs (using different site-proxies) vary significantly, especially for hard-rock sites. This indicates that GMPEs may be poorly constrained where they are sometimes most needed, i.e. for hard rock

Aquatic occurrence of phytotoxins in small streams triggered by biogeography, vegetation growth stage, and precipitation

Toxic plant secondary metabolites (PSMs), so-called phytotoxins, occur widely in plant species. Many of these phytotoxins have similar mobility, persistence, and toxicity properties in the environment as anthropogenic micropollutants, which increasingly contaminate surface waters. Although recent case studies have shown the aquatic relevance of phytotoxins, the overall exposure remains unknown. Therefore, we performed a detailed occurrence analysis covering 134 phytotoxins from 27 PSM classes. Water samples from seven small Swiss streams with catchment areas from 1.7 to 23 km(2) and varying land uses were gathered over several months to investigate seasonal impacts. They were complemented with samples from different biogeographical regions to cover variations in vegetation. A broad SPE-LC-HRMS/MS method was applied with limits of detection below 5 ng/L for over 80% of the 134 included phytotoxins. In total, we confirmed 39 phytotoxins belonging to 13 PSM classes, which corresponds to almost 30% of all included phytotoxins. Several alkaloids were regularly detected in the low ng/L-range, with average detection frequencies of 21%. This is consistent with the previously estimated persistence and mobility properties that indicated a high contamination potential. Coumarins were previously predicted to be unstable, however, detection frequencies were around 89%, and maximal concentrations up to 90 ng/L were measured for fraxetin produced by various trees. Overall, rainy weather conditions at full vegetation led to the highest total phytotoxin concentrations, which might potentially be most critical for aquatic organisms

Genome sequencing and population genomic analyses provide insights into the adaptive landscape of silver birch

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