1,070 research outputs found

    Nantucket Pine Tip Moth (Lepidoptera: Tortricidae) Infestation Rates Related to Site and Stand Characteristics in Nacogdoches County, Texas

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    Twenty-two pine stands with a variety of site and stand characteristics and management strategies were analyzed using discriminant analysis to determine factors which influence Nantucket pine tip moth infestations. A whole-tree sequential sampling scheme designed to estimate absolute infestation rates (±5%) was used. An 8% infestation rate was used as the dividing line between high and low tip moth infestations. A sequential sampling program was used in the field to estimate populations. Absolute infestation rates (P ± 5%), were obtained through random selection of pines for whole-tree sampling. Four equations were developed which gave 91% correct classification of initial data. The discriminating variables included site preparation intensity, pine height, pine age, site index, soil texture at 61 cm depth, depth of A horizon multiplied by soil texture code, and depth of clay

    Attentional biases for food stimuli in external eaters: Possible mechanism for stress-induced eating?

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    External eaters reportedly increase snack intake when stressed, which could be due to an attentional shift towards food stimuli. Attentional biases for food stimuli were tested in high and low external eaters in stress and control conditions, using a computerised Stroop. A significant interaction was observed between external eating group and condition for snack word bias. This suggested that low external eaters have a greater bias for snack words when unstressed and that stressed, high external eaters have a greater bias for snack words than stressed, low external eaters, which could contribute to stress-induced snack intake in high external eaters

    Predicting breastfeeding in women living in areas of economic hardship : explanatory role of the theory of planned behaviour

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    This study employed the theory of planned behaviour (TPB) and additional variables (descriptive norm, moral norm, self-identity) to investigate the factors underlying breastfeeding intention and subsequent breastfeeding at four time points (during hospital stay, at hospital discharge, 10 days postpartum and 6 weeks postpartum) in a sample of women selected from defined areas of economic hardship (N = 248). A model containing the TPB, additional variables and demographic factors provided a good prediction of both intention (R-2 = 0.72; attitude, perceived behavioural control, moral norm and self-identity significant predictors) and behaviour - breastfeeding at birth (88.6% correctly classified; household deprivation, intention, attitude significant), at discharge from hospital (87.3% correctly classified; intention, attitude significant), 10 days after discharge (83.1% correctly classified; education, intention, attitude, descriptive norm significant) and 6 weeks after discharge (78.0% correctly classified; age, household deprivation, ethnicity, moral norm significant). Implications for interventions are discussed, such as the potential usefulness of targeting descriptive norms, moral norms and perceived behavioural control (PBC) when attempting to increase breastfeeding uptake

    Chemotropic guidance facilitates axonal regeneration and synapse formation after spinal cord injury.

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    A principal objective of spinal cord injury (SCI) research is the restoration of axonal connectivity to denervated targets. We tested the hypothesis that chemotropic mechanisms would guide regenerating spinal cord axons to appropriate brainstem targets. We subjected rats to cervical level 1 (C1) lesions and combinatorial treatments to elicit axonal bridging into and beyond lesion sites. Lentiviral vectors expressing neurotrophin-3 (NT-3) were then injected into an appropriate brainstem target, the nucleus gracilis, and an inappropriate target, the reticular formation. NT-3 expression in the correct target led to reinnervation of the nucleus gracilis in a dose-related fashion, whereas NT-3 expression in the reticular formation led to mistargeting of regenerating axons. Axons regenerating into the nucleus gracilis formed axodendritic synapses containing rounded vesicles, reflective of pre-injury synaptic architecture. Thus, we report for the first time, to the best of our knowledge, the reinnervation of brainstem targets after SCI and an essential role for chemotropic axon guidance in target selection

    Direct CFD Predictions of Low Frequency Sounds Generated by a Helicopter Main Rotor

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    The use of CFD to directly predict helicopter main rotor noise is shown to be quite promising as an alternative mean for low frequency source noise evaluation. Results using existing state-of-the-art grid structures and finite-difference schemes demonstrated that small perturbation pressures, associated with acoustics radiation, can be extracted with some degree of fidelity. Accuracy of the predictions are demonstrated via comparing to predictions from conventional acoustic analogy-based models, and with measurements obtained from wind tunnel and flight tests for the MD-902 helicopter at several operating conditions. Findings show that the direct CFD approach is quite successfully in yielding low frequency results due to thickness and steady loading noise mechanisms. Mid-to-high frequency contents, due to blade-vortex interactions, are not predicted due to CFD modeling and grid constraints

    The question-behaviour effect: a theoretical and methodological review and meta-analysis

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    Research has demonstrated that asking people questions about a behaviour can lead to behaviour change. Despite many, varied studies in different domains, it is only recently that this phenomenon has been studied under the umbrella term of the question-behaviour effect (QBE) and moderators of the effect have been investigated. With a particular focus on our own contributions, this article: (1) provides an overview of QBE research; (2) reviews and offers new evidence concerning three theoretical accounts of the QBE (behavioural simulation and processing fluency; attitude accessibility; cognitive dissonance); (3) reports a new meta-analysis of QBE studies (k = 66, reporting 94 tests) focusing on methodological moderators. The findings of this meta-analysis support a small significant effect of the QBE (g = 0.14, 95% CI = 0.11, 0.18, p < .001) with smaller effect sizes observed in more carefully controlled studies that exhibit less risk of bias and (4) also considers directions for future research on the QBE, especially studies that use designs with low risk of bias and consider desirable and undesirable behaviour separately

    Are women better than men at multi-tasking?

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    Background: There seems to be a common belief that women are better in multi-tasking than men, but there is practically no scientific research on this topic. Here, we tested whether women have better multi-tasking skills than men.\ensuremath\ensuremath Methods: In Experiment 1, we compared performance of 120 women and 120 men in a computer-based task-switching paradigm. In Experiment 2, we compared a different group of 47 women and 47 men on "paper-and-pencil" multi-tasking tests.\ensuremath\ensuremath Results: In Experiment 1, both men and women performed more slowly when two tasks were rapidly interleaved than when the two tasks were performed separately. Importantly, this slow down was significantly larger in the male participants (Cohen?s d = 0.27). In an everyday multi-tasking scenario (Experiment 2), men and women did not differ significantly at solving simple arithmetic problems, searching for restaurants on a map, or answering general knowledge questions on the phone, but women were significantly better at devising strategies for locating a lost key (Cohen?s d = 0.49).\ensuremath\ensuremath Conclusions: Women outperform men in these multi-tasking paradigms, but the near lack of empirical studies on gender differences in multitasking should caution against making strong generalisations. Instead, we hope that other researchers will aim to replicate and elaborate on our findings.\ensuremath\ensuremath</p\ensuremath

    The impact of asking intention or self-prediction questions on subsequent behavior: a meta-analysis

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    The current meta-analysis estimated the magnitude of the impact of asking intention and self-prediction questions on rates of subsequent behavior, and examined mediators and moderators of this question–behavior effect (QBE). Random-effects meta-analysis on 116 published tests of the effect indicated that intention/prediction questions have a small positive effect on behavior (d+ = 0.24). Little support was observed for attitude accessibility, cognitive dissonance, behavioral simulation, or processing fluency explanations of the QBE. Multivariate analyses indicated significant effects of social desirability of behavior/behavior domain (larger effects for more desirable and less risky behaviors), difficulty of behavior (larger effects for easy-to-perform behaviors), and sample type (larger effects among student samples). Although this review controls for co-occurrence of moderators in multivariate analyses, future primary research should systematically vary moderators in fully factorial designs. Further primary research is also needed to unravel the mechanisms underlying different variants of the QBE

    Trajectory mapping: A tool for validation of trace gas observations

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    We investigate the effectiveness of trajectory mapping(TM) as a data validation tool. TM combines a dynamical model of the atmosphere with trace gas observations to provide more statistically robust estimates of instrument performance over much broader geographic areas than traditional techniques are able to provide. We present four detailed case studies selected so that the traditional techniques are expected to work well. In each case the TM results are equivalent to or improve upon the measurement comparisons performed with traditional approaches. The TM results are statistically more robust than those achieved using traditional approaches since the TM comparisons occur over a much larger range of geophysical variability. In the first case study we compare ozone data from the Halogen Occultation Experiment (HALOE) with Microwave Limb Sounder(MLS). TM comparisons appear to introduce little to no error as compared to the traditional approach. In the second case study we compare ozone data from HALOE with that from the Stratospheric Aerosol and Gas Experiment TT(SAGE TT). TM results in differences of less than 5% as compared to the traditional approach at altitudes between 18 and 25 km and less than 10% at altitudes between 25 and 40 km.In the third case study we show that ozone profiles generated from HALOE data using TM compare well with profiles from five European ozonesondes. In the fourth case study we evaluate the precision of MLS H20 using TM and find typical precision uncertainties of 3-7% at most latitudes and altitudes. The TM results agree well with previous estimates but are the result of a global analysis of the data rather than an analysis in the limited latitude bands in which traditional approaches work. Finally, sensitivity studies using the MLS H20 data show the following: (1) a combination of forward and backward trajectory calculations minimize uncertainties in isentropic TM; (2) although the uncertainty of the technique increases with trajectory duration,TM calculations of up to 14 days can provide reliable information for use in data validation studies; (3) a correlation coincidence criterion of 400 km produces the best TM results under most circumstances; (4) TM performs well compared to (and sometimes better than) traditional approaches at all latitudes and in most seasons and; (5) TM introduces no statistically significant biases at altitudes between 22 and 40 km
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