2,484 research outputs found
The Prevalence of L. monocytogenes in Cull Sows
The goal of this study was to determine the distribution of Listeria monocytogenes in cull sows and their pork. Two trials were conducted at a single packing plant in 2001 (n=179 cull sows) and in 2002 (n= 160 cull sows). Fecal samples collected antemortem (trial 1) as well as animal tissues, carcass, and environmental swabs, and meat block samples collected at the abattoir (trials 1 and 2) were analyzed. When results from both trials were combined, overall L. monocytogenes was detected in five or 0.17% of the total samples (n=2,858). Specifically, L. monocytogenes was confirmed in a tonsil sample (0.55% of tonsils positive) and in a carcass swab sample (0.56% of carcasses) before the organic acid rinse. L. monocytogenes was recovered in three (1.21%) meat block samples (n=213). These data indicate that L. monocytogenes is present in the cull sow and their pork
A Rapid, Handheld Device to Assess Respiratory Resistance: Clinical and Normative Evidence
Introduction: Following reports of respiratory symptoms among service members returning from deployment to South West Asia (SWA), an expert panel recommended pre-deployment spirometry be used to assess disease burden. Unfortunately, testing with spirometry is high cost and time-consuming. The airflow perturbation device (APD) is a handheld monitor that rapidly measures respiratory resistance (APD-Rr) and has promising but limited clinical data. Its speed and portability make it ideally suited for large volume pre-deployment screening. We conducted a pilot study to assess APD performance characteristics and develop normative values. Materials and Methods: We prospectively enrolled subjects and derived reference equations for the APD from those without respiratory symptoms, pulmonary disease, or tobacco exposure. APD testing was conducted by medical technicians who received a 10-min in-service on its use. A subset of subjects performed spirometry and impulse oscillometry (iOS), administered by trained respiratory therapists. APD measures were compared with spirometry and iOS. Results: The total study population included 199 subjects (55.8% males, body mass index 27.7 ± 6.0 kg/m2, age 49.9 ± 18.7 yr). Across the three APD trials, mean inspiratory (APD-Ri), expiratory (APD-Re), and average (APD-Ravg) resistances were 3.30 ± 1.0, 3.69 ± 1.2, and 3.50 ± 1.1 cm H2O/L/s. Reference equations were derived from 142 clinically normal volunteers. Height, weight, and body mass index were independently associated with APD-Ri, APD-Re, and APD-Ravg and were combined with age and gender in linear regression models. APD-Ri, APD-Re, and APD-Ravg were significantly inversely correlated with FEV1 (r = −0.39 to −0.42), FVC (r = −0.37 to −0.40), and FEF25–75 (r = −0.31 to −0.35) and positively correlated with R5 (r = 0.61–0.62), R20 (r = 0.50–0.52), X5 (r = −0.57 to −0.59), and FRES (r = 0.42–0.43). Bland–Altman plots showed that the APD-Rr closely approximates iOS when resistance is normal. Conclusion: Rapid testing was achieved with minimal training required, and reference equations were constructed. APD-Rr correlated moderately with iOS and weakly with spirometry. More testing is required to determine whether the APD has value for pre- and post-deployment respiratory assessment
Cocaine-Dependent Adults and Recreational Cocaine Users Are More Likely Than Controls to Choose Immediate Unsafe Sex Over Delayed Safer Sex
Cocaine users have a higher incidence of risky sexual behavior and HIV infection than non-users.
Our aim was to measure whether safer-sex discount rates, a measure of the likelihood of having
immediate unprotected sex versus waiting to have safer sex, differed between controls and cocaine
users of varying severity. Of the 162 individuals included in the primary data analyses, 69 met
DSM-IV-TR criteria for cocaine dependence, 29 were recreational cocaine users who did not meet
dependence, and 64 were controls. Participants completed the sexual delay discounting task,
which measures one’s likelihood of using a condom when immediately available and how that
likelihood decreases as a function of delay to condom availability with regard to four images
chosen by the participants of hypothetical sexual partners differing in perceived desirability and
likelihood of having a sexually-transmitted infection. When a condom was immediately available,
stated likelihood of condom use sometimes differed between cocaine users and controls, which
depended on the image condition. Even after controlling for rates of condom use when
immediately available, the Cocaine Dependent and Recreational Users groups were more sensitive
to delay to condom availability than controls. Safer-sex discount rates were also related to
intelligence scores. The sexual discounting task identifies delay as a key variable that impacts the
likelihood of using a condom among these groups and suggests that HIV-prevention efforts may be
differentially effective based on an individual’s safer-sex discount rate
Prevalence of Listeria species in camel sausages from retail markets in Aydin province in Turkey and RAPD analysis of Listeria monocytogenes isolates
Samples were taken from 100 camel sausages from the different retail markets in Aydin province in the south-west of Turkey and they were tested for the presence of Listeria spp by biochemical methods. Samples were enriched using Listeria Enrichment Broth and they were inoculated onto Listeria Selective Agar. Listeria monocytogenes was isolated from nine samples (9%), Listeria innocua from 14 samples (14%) and Listeria welshimeri from two samples(2%). A 701 bp fragment of listeriolysin O sequence for L. monocytogenes was amplified using specific primers by polymerase chain reaction (PCR) for confirmation of the identification. A random primer (OPA-11) was used in a random amplified polymorphic DNA (RAPD) assay. This detected five different band profiles amongst the L. monocytogenes isolates, indicating a relatively large amount of genetic heterogeneity amongst the nine isolates. The study has highlighted the need for improved strategies for food safety, in particular appropriate hygienic precautions to avoid contamination of sausage during the manufacturing process and appropriate preservation techniques during storage and transport, to prevent transmission of Listeria spp to consumers at home and abroad
Vertical integration and firm boundaries : the evidence
Since Ronald H. Coase's (1937) seminal paper, a rich set of theories has been developed that deal with firm boundaries in vertical or input–output structures. In the last twenty-five years, empirical evidence that can shed light on those theories also has been accumulating. We review the findings of empirical studies that have addressed two main interrelated questions: First, what types of transactions are best brought within the firm and, second, what are the consequences of vertical integration decisions for economic outcomes such as prices, quantities, investment, and profits. Throughout, we highlight areas of potential cross-fertilization and promising areas for future work
Foreign policy and political possibility
This article explores the relationship between foreign policy and political possibility in two parts. First, the relationship between foreign policy and political possibility is theorized around three analytical moments: political possibility is linked to the framing of conceivable, communicable and coercive foreign policy. Second, this framework is developed and demonstrated through a brief analysis of Coalition foreign policy in the War on Terror, considering American, British and Australian foreign policy between 2001 and 2003. This analysis dissects distinct and divergent Coalition foreign policies through a linked three-part conceptualization of political possibility. It enables an understanding of how the War on Terror was rendered possible through the construction of foreign policy in thinkable, resonant and ultimately dominant terms. The article concludes by looking to the wider analytical applicability of this particular theorization of the relationship between foreign policy and political possibility
A Bayesian Approach to Estimate OJD Prevalence From Pooled Fecal Samples of Variable Pool Size
This paper describes a Bayesian approach to prevalence estimation based on pooled samples that accommodates variation in pool size and adjusts for test imperfection. A logistic model was developed for pooled fecal culture (PFC) sensitivity as a function of pool size and a logistic mixed model for ovine Johne’s disease (OJD) prevalence as a function of covariates that were found significant in a recent OJD risk factor study conducted in Australia. Available data on these factors and prior information about prevalence and sensitivity were incorporated into a Bayesian model to estimate OJD prevalence from PFC data. Overall, posterior cohort OJD prevalence was estimated to be 0.16 (range of prevalences across cohorts 0.002 to 0.72). The average prevalence was higher in wethers than ewes. PFC sensitivities for pool sizes 10, 30 and 50 were estimated to be 0.91 (95% probability intervals 0.80, 0.96), 0.85 (0.80, 0.90) and 0.77 (0.65, 0.88), respectively. Posterior specificity of PFC was almost perfect though based primarily on the prior. Results suggest the Bayesian model successfully estimated the animal-level prevalence after accounting for variable pool size and imperfect test parameters. The method can be easily adapted for other conditions and diseases where pooled samples are collected. WinBugs code for the article is available online. Key Words: Diagnostic test Mycobacterium Ovine Johne’s disease Paratuberculosis Prevalence Sensitivit
Developing an agenda for research about policies to improve access to healthy foods in rural communities: a concept mapping study
Background
Policies that improve access to healthy, affordable foods may improve population health and reduce health disparities. In the United States most food access policy research focuses on urban communities even though residents of rural communities face disproportionately higher risk for nutrition-related chronic diseases compared to residents of urban communities. The purpose of this study was to (1) identify the factors associated with access to healthy, affordable food in rural communities in the United States; and (2) prioritize a meaningful and feasible rural food policy research agenda.
Methods
This study was conducted by the Rural Food Access Workgroup (RFAWG), a workgroup facilitated by the Nutrition and Obesity Policy Research and Evaluation Network. A national sample of academic and non-academic researchers, public health and cooperative extension practitioners, and other experts who focus on rural food access and economic development was invited to complete a concept mapping process that included brainstorming the factors that are associated with rural food access, sorting and organizing the factors into similar domains, and rating the importance of policies and research to address these factors. As a last step, RFAWG members convened to interpret the data and establish research recommendations.
Results
Seventy-five participants in the brainstorming exercise represented the following sectors: non-extension research (n = 27), non-extension program administration (n = 18), “other� (n = 14), policy advocacy (n = 10), and cooperative extension service (n = 6). The brainstorming exercise generated 90 distinct statements about factors associated with rural food access in the United States; these were sorted into 5 clusters. Go Zones were established for the factors that were rated highly as both a priority policy target and a priority for research. The highest ranked policy and research priorities include strategies designed to build economic viability in rural communities, improve access to federal food and nutrition assistance programs, improve food retail systems, and increase the personal food production capacity of rural residents. Respondents also prioritized the development of valid and reliable research methodologies to measure variables associated with rural food access.
Conclusions
This collaborative, trans-disciplinary, participatory process, created a map to guide and prioritize research about polices to improve healthy, affordable food access in rural communities
No Differences in Soil Carbon Stocks Across the Tree Line in the Peruvian Andes
ABSTRACT Reliable soil organic carbon (SOC) stock measurements of all major ecosystems are essential for predicting the influence of global warming on global soil carbon pools, but hardly any detailed soil survey data are available for tropical montane cloud forests (TMCF) and adjacent high elevation grasslands above (puna). TMCF are among the most threatened of ecosystems under current predicted global warming scenarios. We conducted an intensive soil sampling campaign extending 40 km along the tree line in the Peruvian Andes between 2994 and 3860 m asl to quantify SOC stocks of TMCF, puna grassland, and shrubland sites in the transition zone between the two habitats. SOC stocks from the soil surface down to the bedrock averaged (±standard error SE) 11.8 (±1.5, N = 24) kg C/m 2 in TMCF, 14.7 (±1.4, N = 9) kg C/m 2 in the shrublands and 11.9 (±0.8, N = 35) kg C/m 2 in the grasslands and were not significantly different (P > 0.05 for all comparisons). However, soil profile analysis revealed distinct differences, with TMCF profiles showing a uniform SOC distribution with depth, shrublands a linear decrease, and puna sites an exponential decrease in SOC densities with soil depth. Organic soil layer thickness reached a maximum ($70 cm) at the upper limit of the TMCF and declined with increasing altitude toward puna sites. Within TMCF, no significant increase in SOC stocks with increasing altitude was observed, probably because of the large variations among SOC stocks at different sites, which in turn were correlated with spatial variation in soil depth
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