412 research outputs found

    Dispersal, Flight, and Diurnal Activity Patterns of Adult Southern Corn Billbugs (Coleoptera: Curculionidae)

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    Dispersal into cornfields, flight, and diurnal activity patterns of the adult southern com billbug (SCB), Sphenophorus callosus (Olivier), were studied in eastern North Carolina during 1979 and 1980. Com plant damage (an index of SCB density) in fields with different cropping histories was initially concentrated either on the field edge next to last year\u27s corn in rotated fields, or the edge next to the overwintering site in nonrotated fields. Although damage patterns and trapping studies suggested that SCB dispersal into fields was primarily by walking, SCB are capable of strong flight. Weevils of both the overwintered and summer generations were caught in flight traps. Diurnal activity patterns of adult SCB were often bimodal; peak numbers of adults were found on plants and caught in pitfall traps in late morning and mid- to late afternoon. Changes in adult activity appeared to be better explained by changes in temperature than by changes in light intensity. Least activity occurred when temperatures were above 30°C or below 20°C

    Dispersal, Flight, and Diurnal Activity Patterns of Adult Southern Corn Billbugs (Coleoptera: Curculionidae)

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    Dispersal into cornfields, flight, and diurnal activity patterns of the adult southern com billbug (SCB), Sphenophorus callosus (Olivier), were studied in eastern North Carolina during 1979 and 1980. Com plant damage (an index of SCB density) in fields with different cropping histories was initially concentrated either on the field edge next to last year\u27s corn in rotated fields, or the edge next to the overwintering site in nonrotated fields. Although damage patterns and trapping studies suggested that SCB dispersal into fields was primarily by walking, SCB are capable of strong flight. Weevils of both the overwintered and summer generations were caught in flight traps. Diurnal activity patterns of adult SCB were often bimodal; peak numbers of adults were found on plants and caught in pitfall traps in late morning and mid- to late afternoon. Changes in adult activity appeared to be better explained by changes in temperature than by changes in light intensity. Least activity occurred when temperatures were above 30°C or below 20°C

    Research Notes: Techniques developed for screening soybeans for Mexican bean beetle resistance

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    The lack of uniform infestations of Mexican bean beetle (Epilachna varivestis Mulsant) in field plantings can make selection for resistance in segregating soybean populations very difficult . For this reason, the results from screening F2 plants in the field have been inconsistent. An alternative is to advance F2 plants to the F3 to provide replication at more than one location

    Determinants of Physical Activity and Low-Fat Diet Among Low Income African American and Hispanic Middle School Students

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    African Americans, Hispanics, and those with low income experience disproportionate health problems that can be prevented by physical activity and a lower fat diet. In this descriptive cross-sectional study, antecedents of diet and exercise within the Health Promotion/Transtheoretical Model were examined among low-income African American and Hispanic seventh-grade students (n = 127). Total support was associated with higher physical activity for girls. African Americans perceived greater social support for activity than Hispanics. Family models and support for physical activity and low-fat diet were greater as family income increased. However, higher family role models and lower dietary fat were found among the lowest income Hispanic students\u27 residing ZIP code with a higher concentration of Hispanics and greater availability of Hispanic foods and culture. A school-based approach may be useful to build peer support for physical activity and lower dietary fat. Parish nurse or clinic settings may be most appropriate for building family role models and support. Living in a neighborhood with traditional Hispanic culture and foods appears to have ameliorated the harmful effects of lower income, although further study with larger samples followed over time is needed

    Effectiveness of a school-community linked program on physical activity levels and health-related quality of life for adolescent girls

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    Background: This study evaluated the effectiveness of a school-community program on Health-Related Quality of Life (HRQoL; the primary outcome), physical activity (PA), and potential mediators of PA among adolescent girls living in low-socioeconomic rural/regional settings. Method: The study was a cluster-randomized controlled trial. Twelve communities with the requisite sports clubs and facilities were paired according to relevant criteria; one of each pair was randomly assigned to the intervention or control condition. Eight schools per condition were randomly selected from these communities and the intervention was conducted over one school year (2011). Female students in grades 7–9 in intervention schools participated in two 6-session PA units – a sport unit (football or tennis) and a recreational unit (leisure centre-based). These were incorporated into physical education (PE) curriculum and linked to PA opportunities for participation outside school. Students were surveyed at baseline and endpoint, self-reporting impact on primary and secondary outcome measures (HRQoL, PA) and PA mediators (e.g. self-efficacy). Linear mixed models for two-group (intervention, control) and three-group (completers, non-completers, control) analyses were conducted with baseline value, age and BMI as covariates, group as a fixed effect and school as random cluster effect. Results: Participants completing baseline and endpoint measures included: 358 intervention (baseline response rate 33.7%, retention rate 61.3%) and 256 control (14.1% and 84.0%). Adjustment for age and BMI made no substantive difference to outcomes, and there were no cluster effects. For HRQoL, after adjustment for baseline scores, the intervention group showed significantly higher scores on all three PedsQL scores (physical functioning: M ± SE = 83.9 ± 0.7, p = .005; psychosocial: 79.9 ± 0.8, p = .001; total score: 81.3 ± 0.7, p = .001) than the control group (80.9 ± 0.8; 76.1 ± 0.9 and 77.8 ± 0.8). The three-group analysis found intervention non-completers had significantly higher PedsQL scores (84.0 ± 0.8, p = .021; 80.4 ± 0.9, p = .003; 81.7 ± 0.8, p = .002;) than controls (80.9 ± 0.8, 76.1 ± 0.9 and 77.8 ± 0.8). There were no significant differences for any PA measure. Intervention completers had significantly higher scores than non-completers and controls for some mediator variables (e.g. self-efficacy, behavioural control). Conclusion: Positive outcomes were achieved from a modest school-community linked intervention. The school component contributed to maintaining HRQoL; students who completed the community component derived a range of intra-personal and inter-personal benefits

    Cortical depth dependent functional responses in humans at 7T: improved specificity with 3D GRASE

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    Ultra high fields (7T and above) allow functional imaging with high contrast-to-noise ratios and improved spatial resolution. This, along with improved hardware and imaging techniques, allow investigating columnar and laminar functional responses. Using gradient-echo (GE) (T2* weighted) based sequences, layer specific responses have been recorded from human (and animal) primary visual areas. However, their increased sensitivity to large surface veins potentially clouds detecting and interpreting layer specific responses. Conversely, spin-echo (SE) (T2 weighted) sequences are less sensitive to large veins and have been used to map cortical columns in humans. T2 weighted 3D GRASE with inner volume selection provides high isotropic resolution over extended volumes, overcoming some of the many technical limitations of conventional 2D SE-EPI, whereby making layer specific investigations feasible. Further, the demonstration of columnar level specificity with 3D GRASE, despite contributions from both stimulated echoes and conventional T2 contrast, has made it an attractive alternative over 2D SE-EPI. Here, we assess the spatial specificity of cortical depth dependent 3D GRASE functional responses in human V1 and hMT by comparing it to GE responses. In doing so we demonstrate that 3D GRASE is less sensitive to contributions from large veins in superficial layers, while showing increased specificity (functional tuning) throughout the cortex compared to GE

    Quantifying MRI frequency shifts due to structures with anisotropic magnetic susceptibility using pyrolytic graphite sheet

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    Magnetic susceptibility is an important source of contrast in magnetic resonance imaging (MRI), with spatial variations in the susceptibility of tissue affecting both the magnitude and phase of the measured signals. This contrast has generally been interpreted by assuming that tissues have isotropic magnetic susceptibility, but recent work has shown that the anisotropic magnetic susceptibility of ordered biological tissues, such as myelinated nerves and cardiac muscle fibers, gives rise to unexpected image contrast. This behavior occurs because the pattern of field variation generated by microstructural elements formed from material of anisotropic susceptibility can be very different from that predicted by modelling the effects in terms of isotropic susceptibility. In MR images of tissue, such elements are manifested at a sub-voxel length-scale, so the patterns of field variation that they generate cannot be directly visualized. Here, we used pyrolytic graphite sheet which has a large magnetic susceptibility anisotropy to form structures of known geometry with sizes large enough that the pattern of field variation could be mapped directly using MRI. This allowed direct validation of theoretical expressions describing the pattern of field variation from anisotropic structures with biologically relevant shapes (slabs, spherical shells and cylindrical shells)

    Soy consumption and risk of COPD and respiratory symptoms: a case-control study in Japan

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    <p>Abstract</p> <p>Background</p> <p>To investigate the relationship between soy consumption, COPD risk and the prevalence of respiratory symptoms, a case-control study was conducted in Japan.</p> <p>Methods</p> <p>A total of 278 eligible patients (244 men and 34 women), aged 50–75 years with COPD diagnosed within the past four years, were referred by respiratory physicians, while 340 controls (272 men and 68 women) were recruited from the community. All participants underwent spirometric measurements of respiratory function. Information on demographics, lifestyle characteristics and habitual food consumption was obtained using a structured questionnaire.</p> <p>Results</p> <p>Total soy consumption was positively correlated with observed lung function measures. The mean soy intake was significantly higher among controls (59.98, SD 50.23 g/day) than cases (44.84, SD 28.5 g/day). A significant reduction in COPD risk was evident for highest versus lowest quartile of daily intake of total soybean products, with adjusted odds ratio (OR) 0.392, 95% CI 0.194–0.793, <it>p </it>for trend 0.001. Similar decreases in COPD risk were associated with frequent and higher intake of soy foods such as tofu and bean sprouts, whereas respiratory symptoms were inversely associated with high consumption of soy foods, especially for breathlessness (OR 0.989, 95% CI 0.982–0.996).</p> <p>Conclusion</p> <p>Increasing soy consumption was associated with a decreased risk of COPD and breathlessness.</p

    A review of multi-component maintenance models with economic dependence

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    In this paper we review the literature on multi-component maintenance models with economic dependence. The emphasis is on papers that appeared after 1991, but there is an overlap with Section 2 of the most recent review paper by Cho and Parlar (1991). We distinguish between stationary models, where a long-term stable situation is assumed, and dynamic models, which can take information into account that becomes available only on the short term. Within the stationary models we choose a classification scheme that is primarily based on the various options of grouping maintenance activities: grouping either corrective or preventive maintenance, or combining preventive-maintenance actions with corrective actions. As such, this classification links up with the possibilities for grouped maintenance activities that exist in practice
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