1,103 research outputs found

    Previous Experiences with Epilepsy and Effectiveness of Information to Change Public Perception of Epilepsy

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    Differences with regard to the effectiveness of health information and attitude change are suggested between people with direct, behavioral experiences with a health topic and people with indirect, nonbehavioral experiences. The effects of three different methods of health education about epilepsy, frequently used in health education practice, are assessed in a pretest posttest design with control groups, controlling for experiences with epilepsy. Subjects were 132 students from teacher-training colleges. After all treatments, attitudes, and knowledge about epilepsy were changed in a positive way. Treatments were found to be equally effective. Before treatment, direct behavioral experiences were related to knowledge and a more positive attitude towards epilepsy. After treatment, subjects with direct behavioral experiences with epilepsy showed less change of attitude and knowledge as compared with subjects with indirect experiences. Direct experiences appear to restrain the processing of new information and attitude change

    Salmonella in Broiler Litter and Properties of Soil at Farm Location

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    Contamination of litter in a broiler grow-out house with Salmonella prior to placement of a new flock has been shown to be a precursor of the flock's Salmonella contamination further down the production continuum. In the southern USA, broiler grow-out houses are primarily built on dirt pad foundations that are placed directly on top of the native soil surface. Broiler litter is placed directly on the dirt pad. Multiple grow-out flocks are reared on a single litter batch, and the litter is kept in the houses during downtime between flocks. The effects of environmental determinants on conditions in broiler litter, hence Salmonella ecology within it, has received limited attention. In a field study that included broiler farms in the states of Alabama, Mississippi and Texas we assessed Salmonella in broiler litter at the end of downtime between flocks, i.e. at the time of placement of a new flock for rearing. Here we utilized these results and the U.S. General Soil Map (STATSGO) data to test if properties of soil at farm location impacted the probability of Salmonella detection in the litter. The significance of soil properties as risk factors was tested in multilevel regression models after accounting for possible confounding differences among the farms, the participating broiler complexes and companies, and the farms' geographical positioning. Significant associations were observed between infiltration and drainage capabilities of soil at farm location and probability of Salmonella detection in the litter

    Auditory temporal resolution of a wild white-beaked dolphin (Lagenorhynchus albirostris)

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    Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Journal of Comparative Physiology A: Neuroethology, Sensory, Neural, and Behavioral Physiology 195 (2009): 375-384, doi:10.1007/s00359-009-0415-x.Adequate temporal resolution is required across taxa to properly utilize amplitude modulated acoustic signals. Among mammals, odontocete marine mammals are considered to have relatively high temporal resolution, which is a selective advantage when processing fast traveling underwater sound. However, multiple methods used to estimate auditory temporal resolution have left comparisons among odontocetes and other mammals somewhat vague. Here we present the estimated auditory temporal resolution of an adult male white-beaked dolphin, (Lagenorhynchus albirostris), using auditory evoked potentials and click stimuli. Ours is the first of such studies performed on a wild dolphin in a capture-and-release scenario. The white-beaked dolphin followed rhythmic clicks up to a rate of approximately 1125-1250 Hz, after which the modulation rate transfer function (MRTF) cut-off steeply. However, 10% of the maximum response was still found at 1450 Hz indicating high temporal resolution. The MRTF was similar in shape and bandwidth to that of other odontocetes. The estimated maximal temporal resolution of white-beaked dolphins and other odontocetes was approximately twice that of pinnipeds and manatees, and more than ten-times faster than humans and gerbils. The exceptionally high temporal resolution abilities of odontocetes are likely due primarily to echolocation capabilities that require rapid processing of acoustic cues.We wish to thank the Danish Natural Science Research Council for major financial support (grant no. 272-05-0395)

    Experimental mutation-accumulation on the X chromosome of Drosophila melanogaster reveals stronger selection on males than females

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    <p>Abstract</p> <p>Background</p> <p>Sex differences in the magnitude or direction of mutational effect may be important to a variety of population processes, shaping the mutation load and affecting the cost of sex itself. These differences are expected to be greatest after sexual maturity. Mutation-accumulation (MA) experiments provide the most direct way to examine the consequences of new mutations, but most studies have focused on juvenile viability without regard to sex, and on autosomes rather than sex chromosomes; both adult fitness and X-linkage have been little studied. We therefore investigated the effects of 50 generations of X-chromosome mutation accumulation on the fitness of males and females derived from an outbred population of <it>Drosophila melanogaster</it>.</p> <p>Results</p> <p>Fitness declined rapidly in both sexes as a result of MA, but adult males showed markedly greater fitness loss relative to their controls compared to females expressing identical genotypes, even when females were made homozygous for the X. We estimate that these mutations are partially additive (h ~ 0.3) in females. In addition, the majority of new mutations appear to harm both males and females.</p> <p>Conclusions</p> <p>Our data helps fill a gap in our understanding of the consequences of sexual selection for genetic load, and suggests that stronger selection on males may indeed purge deleterious mutations affecting female fitness.</p

    Higher incidence of premenopausal breast cancer in less developed countries; myth or truth?

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    Background: Fundamental etiologic differences have been suggested to cause earlier onset of breast cancer in less developed countries (LDCs) than in more developed countries (MDCs). We explored this hypothesis using world-wide breast cancer incidence data. Methods: We compared international age-standardized incidence rates (ASR) of pre- (<50 years) and postmenopausal (≥50 years) breast cancers as well as temporal trends in ASRs of pre-and postmenopausal breast cancer among selected countries during 1975–2008. We used joinpoint log-linear regression analysis to estimate annual percent changes (APC) for premenopausal and postmenopausal breast cancer in the northern Europe and in Black and White women population in the US. Results: Premenopausal breast cancers comprised a substantially higher proportion of all incident breast cancers in LDCs (average 47.3%) compared to MDCs (average 18.5%). However, the ASR of premenopausal breast cancer was consistently higher in MDCs (29.4/100,000) than LDCs (12.8/100,000). The ASR of postmenopausal cancer was about five-fold higher in the MDCs (307.6/100,000) than the LDCs (65.4/100,000). The APC of breast cancer in Denmark was substantially higher in postmenopausal (1.33%) than premenopausal cancer (0.98%). Higher incidence of breast cancer among the white than black women in the US was pertained only to the postmenopausal cancer. Conclusion: The substantial and consistent lower age-specific incidence of breast cancer in LDCs than in MDCs contradicts the theory of earlier onset. Demographic differences with fewer old women in LDCs and lower prevalence of risk factors of postmenopausal cancer are the most likely explanation to the lower mean age at diagnosis in these countries

    Regulation of CCL2 Expression by an Upstream TALE Homeodomain Protein-Binding Site That Synergizes with the Site Created by the A-2578G SNP

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    CC Chemokine Ligand 2 (CCL2) is a potent chemoattractant produced by macrophages and activated astrocytes during periods of inflammation within the central nervous system. Increased CCL2 expression is correlated with disease progression and severity, as observed in pulmonary tuberculosis, HCV-related liver disease, and HIV-associated dementia. The CCL2 distal promoter contains an A/G polymorphism at position -2578 and the homozygous -2578 G/G genotype is associated with increased CCL2 production and inflammation. However, the mechanisms that contribute to the phenotypic differences in CCL2 expression are poorly understood. We previously demonstrated that the -2578 G polymorphism creates a TALE homeodomain protein binding site (TALE binding site) for PREP1/PBX2 transcription factors. In this study, we identified the presence of an additional TALE binding site 22 bp upstream of the site created by the -2578 G polymorphism and demonstrated the synergistic effects of the two sites on the activation of the CCL2 promoter. Using chromatin immunoprecipitation (ChIP) assays, we demonstrated increased binding of the TALE proteins PREP1 and PBX2 to the -2578 G allele, and binding of IRF1 to both the A and G alleles. The presence of TALE binding sites that form inverted repeats within the -2578 G allele results in increased transcriptional activation of the CCL2 distal promoter while the presence of only the upstream TALE binding site within the -2578 A allele exerts repression of promoter activity

    Risky business: factor analysis of survey data – assessing the probability of incorrect dimensionalisation

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    This paper undertakes a systematic assessment of the extent to which factor analysis the correct number of latent dimensions (factors) when applied to ordered categorical survey items (so-called Likert items). We simulate 2400 data sets of uni-dimensional Likert items that vary systematically over a range of conditions such as the underlying population distribution, the number of items, the level of random error, and characteristics of items and item-sets. Each of these datasets is factor analysed in a variety of ways that are frequently used in the extant literature, or that are recommended in current methodological texts. These include exploratory factor retention heuristics such as Kaiser’s criterion, Parallel Analysis and a non-graphical scree test, and (for exploratory and confirmatory analyses) evaluations of model fit. These analyses are conducted on the basis of Pearson and polychoric correlations.We find that, irrespective of the particular mode of analysis, factor analysis applied to ordered-categorical survey data very often leads to over-dimensionalisation. The magnitude of this risk depends on the specific way in which factor analysis is conducted, the number of items, the properties of the set of items, and the underlying population distribution. The paper concludes with a discussion of the consequences of overdimensionalisation, and a brief mention of alternative modes of analysis that are much less prone to such problems
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