9 research outputs found

    Evaluation of the Suitability of a Commercially Available ELISA Test as a Monitoring Tool for Estimating the Salmonella Prevalence of Commercial Swine Herds

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    In this study we evaluate the suitability of the Salmotype® (Labordiagnostik Leipzig) Enzyme Linked Immunosorbent Assay (ELISA) in swine. The study demonstrated no association between either individual or pen fecal culture and serologic status when examined by linear regression. Culture positive pigs had a tendency to be seropositive based on the individual fecal culture and only at pen and individual levels based on the pen fecal culture. Lowering the suggested cutoff of 40 % to 13 % gave an equal number of culture and seropositive individuals. Therefore further adaptation of Salmotype®to the US swine industry and further additional field studies need to be done

    Evaluation of cross-protection afforded by a Salmonella Choleraesuis vaccine against Salmonella infections in pigs under field conditions

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    This field study investigated the efficacy of a Salmonella Choleraesuis live vaccine (Argus SC™) to reduce the number of infections with Salmonella. Twelve groups of about 380 pigs each were randomly allocated to either vaccination (V) or no vaccination (C). The vaccine was applied orally at 3 and 16 weeks. Forty pigs per group were blood sampled at 3, 10, 16 and 24 weeks to detect possible antibodies against Salmonella. The prevalence of Salmonella in the lymph nodes as the major variable. In the V groups, only 0.6 % of the lymph nodes was positive, whereas 7.2 % was positive in the C groups (p \u3c 0.001). The percentage of seropositive pigs at 24 weeks (cut-off OD \u3e 10) was 26 % and 9 % in the V and C groups, respectively (p \u3c 0.00 I). The present study documented that vaccination with a live modified S. Choleraesuis vaccine is a useful tool to lower the prevalence of Salmonella in swine herds

    Monitoring the Dynamics of Salmonella Prevalence in Commercial Swine Herds

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    The goal of this study was to monitor 47 commercial swine herds at slaughter to determine Salmonella prevalence over a 2 year period. Mesenteric lymph nodes were collected (n=60, pooled 5:1 for a total of 12 samples) at the time of slaughter and cultured. Tissue samples were collected from the diaphragm and tested by ELISA. After a first phase of testing, we identified 10 herds that had both low culture positives and low average ELISA OD values. We also identified 10 herds that had both a high culture positives and high average ELISA OD values. The purpose of testing during Phase II was to see if the I 0 low herds remained low and the I 0 high herds remained high. The findings confirm the need for an on-going monitoring for tracking the changing Salmonella prevalence of swine herds over time

    Automatic recognition of schwa variants in spontaneous Hungarian speech

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    This paper analyzes the nature of the process involved in optional vowel reduction in Hungarian, and the acoustic structure of schwa variants in spontaneous speech. The study focuses on the acoustic patterns of both the basic realizations of Hungarian vowels and their realizations as neutral vowels (schwas), as well as on the design, implementation, and evaluation of a set of algorithms for the recognition of both types of realizations from the speech waveform. The authors address the question whether schwas form a unified group of vowels or they show some dependence on the originally intended articulation of the vowel they stand for. The acoustic study uses a database consisting of over 4,000 utterances extracted from continuous speech, and recorded from 19 speakers. The authors propose methods for the recognition of neutral vowels depending on the various vowels they replace in spontaneous speech. Mel-Frequency Cepstral Coefficients are calculated and used for the training of Hidden Markov Models. The recognition system was trained on 2,500 utterances and then tested on 1,500 utterances. The results show that a neutral vowel can be detected in 72% of all occurrences. Stressed and unstressed syllables can be distinguished in 92% of all cases. Neutralized vowels do not form a unified group of phoneme realizations. The pronunciation of schwa heavily depends on the original articulation configuration of the intended vowel

    Exploiting Prosody for Automatic Syntactic Phrase Boundary Detection in Speech

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    The relation between syntax and prosody is evident, even if the prosodic structure cannot be directly mapped to the syntactic one and vice versa. Syntax-to-prosody mapping is widely used in text-to-speech applications, but prosody-to-syntax mapping is mostly missing from automatic speech recognition/understanding systems. This paper presents an experiment towards filling this gap and evaluating whether a HMM-based automatic prosodic segmentation tool can be used to support the reconstruction of the syntactic structure directly from speech. Results show that up to 85% of syntactic clause boundaries and up to about 70% of embedded syntactic phrase boundaries could be identified based on the detection of phonological phrases. Recall rates do not depend further on syntactic layering, in other words, whether the phrase is multiply embedded or not. Clause boundaries can be well assigned to intonational phrase level in read speech and can be well separated from lower level syntactic phrases based on the type of the aligned phonological phrase(s). These findings can be exploited in speech understanding systems, allowing for the recovery of the skeleton of the syntactic structure, based purely on the speech signal

    Metabolic fingerprinting of bacteria by fluorescence lifetime imaging microscopy

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    Bacterial populations exhibit a range of metabolic states influenced by their environment, intra- and interspecies interactions. The identification of bacterial metabolic states and transitions between them in their native environment promises to elucidate community behavior and stochastic processes, such as antibiotic resistance acquisition. In this work, we employ two-photon fluorescence lifetime imaging microscopy (FLIM) to create a metabolic fingerprint of individual bacteria and populations. FLIM of autofluorescent reduced nicotinamide adenine dinucleotide (phosphate), NAD(P)H, has been previously exploited for label-free metabolic imaging of mammalian cells. However, NAD(P)H FLIM has not been established as a metabolic proxy in bacteria. Applying the phasor approach, we create FLIM-phasor maps of Escherichia coli, Salmonella enterica serovar Typhimurium, Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus epidermidis at the single cell and population levels. The bacterial phasor is sensitive to environmental conditions such as antibiotic exposure and growth phase, suggesting that observed shifts in the phasor are representative of metabolic changes within the cells. The FLIM-phasor approach represents a powerful, non-invasive imaging technique to study bacterial metabolism in situ and could provide unique insights into bacterial community behavior, pathology and antibiotic resistance with sub-cellular resolution

    Direct AKAP-mediated protein-protein interactions as potential drug targets

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    A-kinase-anchoring proteins (AKAPs) are a diverse family of about 50 scaffolding proteins. They are defined by the presence of a structurally conserved protein kinase A (PKA)-binding domain. AKAPs tether PKA and other signalling proteins such as further protein kinases, protein phosphatases and phosphodiesterases by direct protein-protein interactions to cellular compartments. Thus, AKAPs form the basis of signalling modules that integrate cellular signalling processes and limit these to defined sites. Disruption of AKAP functions by gene targeting, knockdown approaches and, in particular, pharmacological disruption of defined AKAP-dependent protein-protein interactions has revealed key roles of AKAPs in numerous processes, including the regulation of cardiac myocyte contractility and vasopressin-mediated water reabsorption in the kidney. Dysregulation of such processes causes diseases, including cardiovascular and renal disorders. In this review, we discuss AKAP functions elucidated by gene targeting and knockdown approaches, but mainly focus on studies utilizing peptides for disruption of direct AKAP-mediated protein-protein interactions. The latter studies point to direct AKAP-mediated protein-protein interactions as targets for novel drugs
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