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21.
This study examined the clinical significance of self‐reported frequency of time spent dieting in obese patients with binge eating disorder (BED). A total of 207 treatment‐seeking obese BED patients (57 men and 150 women) were dichotomized by dieting frequency and gender and compared on a number of historical, psychological, and metabolic variables. Frequent dieters reported significantly earlier age of onset for binge eating, dieting, and obesity, more episodes of weight cycling, greater weight suppression, and greater eating disorder pathology than infrequent dieters; no differences, however, emerged on current binge eating frequency or psychological distress. Among women but not among men, frequent dieters had consistently lower chances of abnormalities in total cholesterol, high‐density lipoprotein (HDL) cholesterol, and the total/HDL cholesterol ratio while infrequent dieters had greater chances of abnormalities on these variables. Dietary restraint was inversely correlated with abnormalities in triglycerides, HDL cholesterol, and the total/HDL cholesterol ratio but was unrelated to low‐density lipoprotein (LDL) cholesterol. In summary, frequent dieters of both genders had greater lifetime and current eating and weight concerns, and in women, decreased chance of metabolic abnormalities than infrequent dieters. Our findings suggest that frequent dieting attempts, particularly in women, are associated with greater eating disorder pathology but may have a beneficial effect on metabolic functioning and cardiovascular disease risk independent of actual weight status. These findings may have implications for clinical advice provided to obese BED patients.  相似文献   
22.
There have been few studies quantifying litterfall, standing litterstock and gross litter decomposition following forest conversion to plantation crops such as cocoa. Additionally, an assessment of changing processes occurring in forest floor litter systems with plantation age is lacking. We investigated litterfall production, standing litter changes and litter decomposition along a chronosequence of shaded cocoa farm fields (secondary forest, 3, 15 and 30-year-old) in the moist semi-deciduous forest belt in the Ashanti Region of Ghana in West Africa over 24 months. Mean annual litterfall production differed significantly among study sites and ranged from 5.0 to 10.4 Mg DM ha?1. Similarly, standing litter differed significantly between land-use /plot ages. The results showed significant differences in quality between litter from forest and litter from cocoa plantations. Litterfall from forests had higher concentrations of nitrogen and lower concentration of soluble polyphenols and lignin compared to litter from cocoa systems. Monthly decomposition coefficients (k) estimated as $ k = {{\left( {{\text{A}} - \left( {{\text{L}}_1 - {\text{L}}_0 } \right)} \right)} \mathord{\left/ {\vphantom {{\left( {{\text{A}} - \left( {{\text{L}}_1 - {\text{L}}_0 } \right)} \right)} {\left( {{{\left( {{\text{L}}_1 + {\text{L}}_0 } \right)} \mathord{\left/ {\vphantom {{\left( {{\text{L}}_1 + {\text{L}}_0 } \right)} 2}} \right. } 2}} \right)}}} \right. } {\left( {{{\left( {{\text{L}}_1 + {\text{L}}_0 } \right)} \mathord{\left/ {\vphantom {{\left( {{\text{L}}_1 + {\text{L}}_0 } \right)} 2}} \right. } 2}} \right)}} $ , where A is litterfall production during the month, L0 is the standing litterstock at the beginning of the month and L1 is the standing litterstock at the end of the month. Annual decomposition coefficients (k L ) were similar in cocoa systems (0.221–0.227) but higher under secondary forests (0.354). Correlations between litter quality parameters and the decomposition coefficient showed nitrogen and lignin concentrations as well as ratios that include nitrogen are the best predictors of decomposition for the litters studied. Our results confirm the hypothesis that decomposition decreases following forest conversion to shaded cocoa systems because of litter quality changes and that decomposition rates correlate to litter quality differences between forest and cocoa ecosystems. The study also showed that standing litter pools and litterfall production in recently converted cocoa plantations are low compared to secondary forests or mature cocoa systems. Management strategies involving the introduction of upper canopy species during plantation development with corresponding replacement of tree mortality with diverse fast growing species will provide high quality and quantity litter resources.  相似文献   
23.
Most Recent bryozoan species are encrusting sheets, and many of these colonies have densely packed feeding zooids. In this study, I tested whether tight packing of feeding zooids affects food capture. Colonies of a bryozoan with an encrusting sheet form (Membranipora membranacea) were dissected to produce individuals whose feeding zooids were (1) closely packed, (2) more widely spaced, or (3) isolated. For each type, rates of particle ingestion were measured in still water and in a freestream velocity of 2.7 cm s(-1). Ingestion rate increased when zooids were closest together, probably because of reduced refiltration and increased feeding current strength farther from the lophophores. The mean incurrent velocity within 0.02 cm above the center of the lophophore was 0.28 cm s(-1) regardless of zooid spacing; however, when the incurrent velocity was measured more than 0.1 cm from the lophophores, zooids that were close together or spaced one zooid's width apart had significantly faster incurrent velocities than single zooids. Flow visualization suggests that isolated zooids and those spaced far apart refilter more water than zooids that are close together. These results along with the observed trend of increased zooid integration over evolutionary time suggest that the benefits of increasing coordination outweigh the consequences of intrazooid competition.  相似文献   
24.
Plant and Soil - Phenotypic trait variation across environmental gradients and through plant ontogeny is critical in driving ecological processes, especially in agroecosystems where single...  相似文献   
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This study examined the degree of misreport in weight, height, and BMI among overweight adults (n = 392) with binge eating disorder (BED) and tested whether the degree of misreport was associated with eating disorder psychopathology and psychological variables. Male (n = 97) and female (n = 295) participants self‐reported height and weight, and were subsequently measured by clinic staff. Participants also completed a series of diagnostic interviews and self‐report assessments. Discrepancies between self‐reported and measured values were modest. The degree of misreport for weight, height, and BMI was not related to eating disorder features, depression, and self‐esteem. Overall, the errors in self‐reported weight and height by overweight patients with BED were very slight. The degree of discrepancy between self‐reported and measured values was not related to eating disorder or psychological features, suggesting that such data are not biased or systematically related to individual differences in overweight patients with BED.  相似文献   
27.
The expansion (or encroachment) of shrubs in forests and woodlands is generally considered a serious threat to biodiversity. The effects of shrub expansion on forest fauna, however, are poorly understood and likely to depend on the availability of key resources in shrub‐encroached forest. Coranderrk Bushland, like many conservation reserves in south‐eastern Australia, is considered threatened by the spread of an indigenous shrub. We investigated the associations between cover of Yarra burgan (Kunzea leptospermoides (Myrtaceae)), vegetation structure and the occurrence of terrestrial native mammals within the reserve, basing our predictions on prior knowledge of burgan growth habits and fauna habitat preferences. We quantified burgan cover and other potentially important habitat attributes using structure surveys, and used motion‐sensing cameras to detect terrestrial mammals. Dense burgan cover was associated with less grass, a sparser understorey, and more cryptogams, dead trees and coarse woody debris. However, there was no evidence that these changes negatively affected native mammals: burgan cover had little influence on the occurrence of any species except swamp wallabies (Wallabia bicolor), which occurred in all areas of the reserve but shifted from sites with high burgan cover during the day to sites with low cover at night. Our findings contrast with those from grassland shrub‐expansion studies, where fauna generally show strong responses to shrub cover. The effects of shrub expansion on forest fauna may be mitigated by the greater pre‐existing structural diversity in forests or the longer time required for structural changes to be fully realized. The large quantities of dead wood in areas with high shrub cover may also provide compensatory resources for small mammals, while the proximity to un‐encroached areas may enable large herbivores to move between dense shelter and forage. Shrub‐encroached forests clearly provide resources for some native fauna, and management strategies need to consider the potential impacts of shrub removal on these taxa.  相似文献   
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29.
Objective: A randomized controlled trial tested the efficacy of an internet‐based lifestyle behavior modification program for African‐American girls over a 2‐year period of intervention. Research Methods and Procedures: Fifty‐seven overweight (mean BMI percentile, 98.3) African‐American girls (mean age, 13.2 years) were randomly assigned to an interactive behavioral internet program or an internet health education program, the control condition. Overweight parents were also participants in the study. Forty adolescent‐parent dyads (70%) completed the 2‐year trial. Outcome data including BMI, body weight, body composition, and weight loss behaviors were collected at baseline and at 6‐month intervals. A computer server tracked use of the web sites. Results: An intention‐to‐treat statistical approach was used, with the last observation carried forward. In comparison with the control condition, adolescents in the behavioral program lost more mean body fat (BF) (?1.12 ± 0.47% vs. 0.43 ± 0.47% BF, p < 0.05), and parents in the behavioral program lost significantly more mean body weight (?2.43 ± 0.66 vs. ?0.35 ± 0.64 kg, p < 0.05) during the first 6 months. This weight loss was regained over the next 18 months. After 2 years, differences in fat for adolescents (?0.08 ± 0.71% vs. 0.84 ± 0.72% BF) and weight for parents (?1.1 ± 0.91 vs. ?0.60 ± 0.89 kg) did not differ between the behavioral and control programs. Discussion: An internet‐based weight management program for African‐American adolescent girls and their parents resulted in weight loss during the first 6 months but did not yield long‐term loss due to reduced use of the web site over time.  相似文献   
30.
This study examined the frequency of the metabolic syndrome (MetSyn) and explored behavioral eating‐ and weight‐related correlates in obese patients with binge eating disorder (BED). Ninety‐three treatment‐seeking obese BED patients (22 men and 71 women) with and without the MetSyn were compared on demographic features and a number of current and historical eating and weight variables. Sixty percent of the obese patients with BED met criteria for the MetSyn, with men and whites having significantly higher rates than women and African Americans, respectively. Patients with vs. without coexisting MetSyn did not differ significantly in self‐reported frequency of binge eating or severity of eating disorder psychopathology. Multivariate hierarchical logistic regression analysis revealed that, after controlling for gender, ethnicity, and BMI, fewer episodes of weight cycling and regular meal skipping were significant predictors of the MetSyn. These findings suggest that lifestyle behaviors including weight loss attempts and regular meal consumption may be potential targets for prevention and/or treatment of the MetSyn in obese patients with BED.  相似文献   
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