77 research outputs found
Organic acids for control of Salmonella in different feed materials
Background: Salmonella control in animal feed is important in order to protect
animal and public health. Organic acids is one of the control measures used
for treatment of Salmonella contaminated feed or feed ingredients. In the
present study, the efficacy of formic acid (FA) and different blends of FA,
propionic acid (PA) and sodium formate (SF) was investigated. Four Salmonella
strains isolated from feed were assayed for their acid tolerance. Also, the
effect of lower temperatures (5°C and 15°C) compared to room temperature was
investigated in rape seed and soybean meal. Results: The efficacy of acid
treatments varied significantly between different feed materials. The
strongest reduction was seen in pelleted and compound mash feed (2.5 log10
reduction) followed by rapeseed meal (1 log10 reduction) after 5 days
exposure. However, in soybean meal the acid effects were limited (less than
0.5 log10 reduction) even after several weeksâ exposure. In all experiments
the survival curves showed a concave shape, with a fast initial death phase
followed by reduction at a slower rate during the remaining time of the
experiment. No difference in Salmonella reduction was observed between FA and
a blend of FA and PA, whereas a commercial blend of FA and SF (Amasil) was
slightly more efficacious (0.5-1 log10 reduction) than a blend of FA and PA
(Luprocid) in compound mash feed. The Salmonella Infantis strain was found to
be the most acid tolerant strain followed by, S. Putten, S. Senftenberg and S.
Typhimurium. The tolerance of the S. Infantis strain compared with the S.
Typhimurium strain was statistically significant (p<0.05). The lethal effect
of FA on the S. Typhimurium strain and the S. Infantis strain was lower at 5°C
and 15°C compared to room temperatures. Conclusions: Acid treatment of
Salmonella in feed is a matter of reducing the number of viable bacterial
cells rather than eliminating the organism. Recommendations on the use of
acids for controlling Salmonella in feed should take into account the relative
efficacy of acid treatment in different feed materials, the variation in acid
tolerance between different Salmonella strains, and the treatment temperature
Associations of interruptions to leisure-time sedentary behaviour with symptoms of depression and anxiety
Interruptions to time spent sitting can ameliorate detrimental metabolic-health consequences of high volumes of sedentary time, but their potential mental health benefits have not been examined. We used the Swedish Health Profile Assessment database, a general health assessment offered to all employees working for companies or organisations connected to occupational and health services. Cross-sectional analyses examined data from 40,550 employees (60% male, mean ageâ=â42 years), collected in 2017â2019. Participants reported the proportion of time (almost always; 75% of the time; 50% of the time; 25% of the time; and almost never) usually spent in leisure-time sedentary behaviours; and, separately, the frequency (never; rarely; sometimes; often; and very often) of interruptions (every 30âmin) to sedentary time. Logistic regression models assessed associations of sedentary time, and the frequency of interruptions to sedentary time, with depression/anxiety symptoms. Fully adjusted models included physical exercise. Compared to those in the lowest sedentary time category, those in the medium and high categories had 1.52 (95% confidence interval (CI)â=â1.40â1.66) and 3.11 (95% CIâ=â2.82â3.42) higher odds of frequent depression/anxiety symptoms, respectively. Compared to those who never/rarely interrupted their sedentary time, those who reported interruptions sometimes, often and very often had 0.72 (95% CIâ=â0.65â0.80), 0.59 (95% CIâ=â0.53â0.65), and 0.53 (95% CIâ=â0.46â0.59) lower odds of depression/anxiety symptoms, respectively. In stratified analyses, more frequent interruptions to sedentary time were associated with lower odds of depression/anxiety symptoms, except among those in the lowest interruptions categories (never/25% of the time). More regularly interrupting sitting during leisure-time may reduce the odds of experiencing symptoms of depression and anxiety
Efficacy of an external chromia layer in reducing nitridation of high temperature alloys
Six high temperature alloys have been exposed in N2/H2 environments at 900 \ub0C. In order to study the efficacy of a chromia barrier layer against nitrogen ingress, experiments were performed in two environments having the same N2/H2 ratio but slightly different water content, chromia formation being spontaneous in one case only. The samples were evaluated by SEM/STEM/EDX, XRD, gravimetry and GD-OES. The presence of an external chromia scale reduced nitridation of the alloy by 50â95%. Furthermore, in the presence of a continuous alumina layer no nitridation of the alloy was detected
Malmbanan Diaries
This booklet is a report for a case study visit during four day field trip, a group of nine PhD students and their supervisors â all part of the National Research School for Architecture and Planning in the Urban Landscape, APULA â set out to explore what may be considered the outback of Western Europeâs conurbations, the transnational region of Kiruna -Narvik.Both âremoteâ and âresourcefulâ, âthreatenedâ and âthrivingâ (equally relative notions), this region seemed to offer possibilities to reflect upon many of the current tendencies influencing contemporary planning practice and research
Modelling the monthly abundance of Culicoides biting midges in nine European countries using Random Forests machine learning
Background: Culicoides biting midges transmit viruses resulting in disease in ruminants and equids such as bluetongue, Schmallenberg disease and African horse sickness. In the past decades, these diseases have led to important economic losses for farmers in Europe. Vector abundance is a key factor in determining the risk of vector-borne disease spread and it is, therefore, important to predict the abundance of Culicoides species involved in the transmission of these pathogens. The objectives of this study were to model and map the monthly abundances of Culicoides in Europe. Methods: We obtained entomological data from 904 farms in nine European countries (Spain, France, Germany, Switzerland, Austria, Poland, Denmark, Sweden and Norway) from 2007 to 2013. Using environmental and climatic predictors from satellite imagery and the machine learning technique Random Forests, we predicted the monthly average abundance at a 1 km2 resolution. We used independent test sets for validation and to assess model performance. Results: The predictive power of the resulting models varied according to month and the Culicoides species/ensembles predicted. Model performance was lower for winter months. Performance was higher for the Obsoletus ensemble, followed by the Pulicaris ensemble, while the model for Culicoides imicola showed a poor performance. Distribution and abundance patterns corresponded well with the known distributions in Europe. The Random Forests model approach was able to distinguish differences in abundance between countries but was not able to predict vector abundance at individual farm level. Conclusions: The models and maps presented here represent an initial attempt to capture large scale geographical and temporal variations in Culicoides abundance. The models are a first step towards producing abundance inputs for R0 modelling of Culicoides-borne infections at a continental scale
Monthly variation in the probability of presence of adult Culicoides populations in nine European countries and the implications for targeted surveillance
Background: Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) are small hematophagous insects responsible for the transmission of bluetongue virus, Schmallenberg virus and African horse sickness virus to wild and domestic ruminants and equids. Outbreaks of these viruses have caused economic damage within the European Union. The spatio-temporal distribution of biting midges is a key factor in identifying areas with the potential for disease spread. The aim of this study was to identify and map areas of neglectable adult activity for each month in an average year. Average monthly risk maps can be used as a tool when allocating resources for surveillance and control programs within Europe. Methods : We modelled the occurrence of C. imicola and the Obsoletus and Pulicaris ensembles using existing entomological surveillance data from Spain, France, Germany, Switzerland, Austria, Denmark, Sweden, Norway and Poland. The monthly probability of each vector species and ensembles being present in Europe based on climatic and environmental input variables was estimated with the machine learning technique Random Forest. Subsequently, the monthly probability was classified into three classes: Absence, Presence and Uncertain status. These three classes are useful for mapping areas of no risk, areas of high-risk targeted for animal movement restrictions, and areas with an uncertain status that need active entomological surveillance to determine whether or not vectors are present. Results: The distribution of Culicoides species ensembles were in agreement with their previously reported distribution in Europe. The Random Forest models were very accurate in predicting the probability of presence for C. imicola (mean AUC = 0.95), less accurate for the Obsoletus ensemble (mean AUC = 0.84), while the lowest accuracy was found for the Pulicaris ensemble (mean AUC = 0.71). The most important environmental variables in the models were related to temperature and precipitation for all three groups. Conclusions: The duration periods with low or null adult activity can be derived from the associated monthly distribution maps, and it was also possible to identify and map areas with uncertain predictions. In the absence of ongoing vector surveillance, these maps can be used by veterinary authorities to classify areas as likely vector-free or as likely risk areas from southern Spain to northern Sweden with acceptable precision. The maps can also focus costly entomological surveillance to seasons and areas where the predictions and vector-free status remain uncertain
Biomarkers of the involvement of mast cells, basophils and eosinophils in asthma and allergic diseases
Biomarkers of the involvement of mast cells, basophils and eosinophils in asthma and allergic diseases
Biomarkers of disease activity have come into wide use in the study of mechanisms of human disease and in clinical medicine to both diagnose and predict disease course; as well as to monitor response to therapeutic intervention. Here we review biomarkers of the involvement of mast cells, basophils, and eosinophils in human allergic inflammation. Included are surface markers of cell activation as well as specific products of these inflammatory cells that implicate specific cell types in the inflammatory process and are of possible value in clinical research as well as within decisions made in the practice of allergy-immunology
Toward an enzyme-based oxygen scavenging laminate. Influence of industrial lamination conditions on the performance of glucose oxidase
The laminate consisted of several polymer layers, aluminium, and one cellulose-based layer containing the active enzymatic system (e.g., glucose oxidase, catalase, glucose, and CaCO3). During the industrial lamination process, the enzyme layer was exposed to three temperature spikes up to 325degreesC without significant enzyme inactivation. Ninety-seven percent of the glucose oxidase activity still remained after the lamination process. The best laminate had an oxygen absorbing capacity of 7.6 +/- 1.0 L/m(2). A reference that was not laminated expressed a corresponding oxygen absorbing capacity of 7.1 +/- 0.8 L/m(2)
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