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31.
B. L. Bennett R. D. Hagan K. A. Huey C. Minson D. Cain 《European journal of applied physiology and occupational physiology》1995,70(4):322-328
This study evaluated the effectiveness of a six-pack versus a four-pack cool vest in reducing heat strain in men dressed in firefighting ensemble, while resting and exercising in a warm/humid environment [34.4°C (day bulb), 28.9°C (wet bulb)]. Male volunteers (n = 12) were monitored for rectal temperature (T
re), mean skin temperature (T
sk), heart rate, and energy expenditure during three test trials: control (no cool vest), four-pack vest, and six-pack vest. The cool vests were worn under the firefighting ensemble and over Navy dungarees. The protocol consisted of two cycles of 30 min seated rest and 30 min walking on a motorized treadmill (1.12 m · s–1, 0% grade). Tolerance time for the control trial (93 min) was significantly less than both vest trials (120 min). Throughout heat exposure, energy expenditure varied during rest and exercise, but no differences existed among all trials (P > 0.05). During the first 60 min of heat exposure, physiological responses were similar for the four-pack and six-pack vests. However, during the second 60 min of heat exposure the six-pack vest had a greater impact on reducing heat strain than the four-pack vest. PeakT
e andT
sk at the end of heat exposure for 6-pack vest [mean (SD) 38.0(0.3)°C and 36.8(0.7)°C] were significantly lower compared to four-pack [38.6 (0.4)°C and 38.1(0.5)°C] and controls [38.9(0.5)°C and 38.4(0.5)°C]. Our findings suggest that the six-pack vest is more effective than the four-pack vest at reducing heat strain and improves performance of personnel wearing a firefighting ensemble. 相似文献
32.
The cost of mutualism in a fly-fungus interaction 总被引:2,自引:0,他引:2
The movement ability of individuals has become increasingly important to a variety of ecological questions. In this study,
I investigate how plant structure and changes in body size through development affect the movement ability of a predaceous
stinkbug, Podisus maculiventris, on three species of goldenrod (Solidago spp.) representing a wide range of surface complexities. I adapt existing techniques for quantifying movement in two dimensions
to the study of movement on natural plant structures in three dimensions. These experiments indicate that plant structure
and insect size are significant factors affecting the movement ability of P. maculiventris. Changes in movement ability due to factors of ontogeny and different habitat structures suggest that the scale of an individual’s
ambit or ecological sphere of influence may vary within its lifespan. Considering the influence of ontogeny and habitat structure
on movement ability may be useful to investigations of population dynamics, foraging behavior, and pest management.
Received: 14 July 1999 / Accepted: 23 March 2000 相似文献
33.
Mikael Fogelholm Urho Kujala Jaakko Kaprio Seppo Sarna 《Obesity (Silver Spring, Md.)》2000,8(5):367-373
Objective: Studies on weight change and mortality have yielded inconclusive results. This 10‐year prospective study was undertaken to improve understanding of factors affecting weight change. Research Methods and Procedures: The subjects were 1143 men, aged 36 to 88 years (mean, 53.3 years) at entry. A questionnaire was filled in at entry and at the end of the follow‐up with queries on weight, height, weight at the age of 20, physician‐diagnosed diseases, smoking, alcohol use, dietary habits, leisure physical activity, occupation, present occupational activity, living conditions (living alone or cohabiting), and former athletic status. Further information on morbidity was obtained from selected national registers. Factors predicting weight change during the study were identified by stepwise linear multiple regression analysis. Results: The mean 10‐year weight change was 0.8 (range, ?29 to +24) kg. Age at entry (β‐coefficient, ?0.17, SE 0.02), weight at entry (β, ?0.03, SE 0.01), diabetes at entry (β, ?3.55, SE 1.02), diabetes diagnosed after entry (β, ?3.94, SE 0.96), malignant cancer (β, ?1.60, SE 0.70), being a smoker (β, ?1.59, SE 0.48), and increased physical activity (β, ?1.27, SE 0.54) were significantly (p < 0.05) associated with weight loss in the final model. The model explained 13% of the variance of weight change. Discussion: The results emphasize the complexity of weight change. Some factors associated with weight change are apparently negatively, and some positively, associated with health. This could explain the equivocal findings on weight change and mortality in the literature. 相似文献
34.
Seasonal changes in the reproductive and life‐history traits of Chrysomela populi L. were investigated in Shobara (34°52′N, 133°01′E), Japan, in 2004 and 2005. Larvae were hatched and reared under natural photoperiod and temperature in 8 different periods between late April and early September in 2004. The incidence of adult diapause increased with progression of the season in 2004. The critical timing of diapause induction, as defined by 50% of females entering diapause, was estimated to occur between late July and early August. No effects of season on the survival rate from hatching to adult emergence, percentage ovipositing females and percentage females that deposited viable eggs were clearly detected. Adult weight at emergence fluctuated seasonally, which was probably caused by air temperature. No effect of season on the oviposition period was observed among females that averted diapause. Females that entered diapause in 2004 started oviposition from the first day of May in 2005. Reproductive output was significantly greater in diapause females than in non‐diapause females. This increase in the reproductive output of diapause females was caused by elongation of the oviposition period and consequently by enlargement of the number of egg clutches deposited. These results suggest that the seasonal timing of diapause induction in females of C. populi would be affected by various risks and benefits to reproduction and survival. 相似文献
35.
A Comparison of Bone Mineral Density and Its Predictors in HIV-Infected and HIV-Uninfected Older Men
《Endocrine practice》2021,27(12):1225-1231
ObjectiveBone health in older individuals with HIV infection has not been well studied. This study aimed to compare bone mineral density (BMD), trabecular bone score (TBS), and bone markers between HIV-infected men and age- and body mass index (BMI)-matched HIV-uninfected men aged ≥60 years. We investigated the associations of risk factors related to fracture with BMD, TBS, and bone markers in HIV-infected men.MethodsThis cross-sectional study included 45 HIV-infected men receiving antiretroviral therapy and 42 HIV-uninfected men. Medical history, BMD and TBS measurements, and laboratory tests related to bone health were assessed in all the participants. HIV-related factors known to be associated with bone loss were assessed in the HIV-infected men.ResultsThe mean BMD, TBS, and osteopenia or osteoporosis prevalence were similar among the cases and controls. The HIV-infected men had significantly higher mean N-terminal propeptide of type 1 procollagen and C-terminal cross-linking telopeptide of type I collagen levels. Stepwise multiple linear regression analysis demonstrated that low BMI (lumbar spine, P = .015; femoral neck, P = .018; and total hip, P = .005), high C-terminal cross-linking telopeptide of type I collagen concentration (total hip, P = .042; and TBS, P = .010), and low vitamin D supplementation (TBS, P = .035) were independently associated with low BMD and TBS.ConclusionIn older HIV-infected men with a low fracture risk, the mean BMD and TBS were similar to those of the age- and BMI-matched controls. The mean bone marker levels were higher in the HIV group. Traditional risk factors for fracture, including low BMI, high C-terminal cross-linking telopeptide of type I collagen level, and low vitamin D supplementation, were significant predictors of low BMD and TBS. 相似文献
36.
目的:将非药物性干预措施与传统药物方法治疗极低出生体重儿喂养不耐受的临床疗效进行观察比较。方法:选取哈尔滨医科大学附属第二医院2011年1月至2013年4月出生的喂养不耐受极低出生体重儿110例。按入院顺序随机分为药物治疗组(MED)55例、非药物治疗组(NON-MED)55例。药物治疗组采用红霉素;非药物治疗组采用腹部按摩法与非营养性吸吮。结果:两组患儿经治疗后,MED组腹胀消失天数(4.4±0.5)、呕吐天数(2.2±0.5)、每日呕吐次数(3.5±0.8)、胃潴留量占每日喂养量(18.3±0.8)、达全肠道喂养天数(8.2±0.7);NON-MED组腹胀消失天数(3.7±0.1)、呕吐天数(1.9±0.6)、每日呕吐次数(2.8±0.1)、胃潴留量占每日喂养量(12.6±0.4)、达全肠道喂养天数(6.1±0.3)。各项治疗指标的对比中,差异均有统计学意义(P0.05)。MED组治疗有效率76.4%;NON-MED组治疗有效率83.6%。结论:非药物性干预措施可有效改善极低出生体重儿喂养不耐受。 相似文献
37.
《Biomarkers》2013,18(1):65-73
Context: It is known that there are usually several biomarkers and/or medium combinations that can be applied to answer a specific exposure question. To help determine an appropriate combination for the specific question, we have developed a weight-of-evidence Framework that provides a relative appropriateness score for competing combinations.Methods: The Framework is based on an expert assessor’s evaluation of the relevance and suitability of the biomarker and medium for the question based on a set of criteria. We provide a computer based modeling tool to guide the researcher through the process.Results: We present an example with six biomarkers of benzene exposure in one matrix; the six are either the most commonly used biomarkers and/or have recent widespread usage. The example clearly demonstrates the usefulness of the Framework for scoring the choices, as well as the transparency of the method that provides the basis for discussion.Conclusions: The Framework provides for the first time a method to transparently document the rationale behind selecting, from among a set of alternatives, the most scientifically supportable exposure biomarker to address a specific biomonitoring question, thus providing a reproducible account of expert opinions on the suitability of a biomarker. 相似文献
38.
《Saudi Journal of Biological Sciences》2022,29(7):103310
A part of the big three cereal crops in the world, wheat has become a major constituent of the everyday food chain and is grown at a massive scale to meet global demands. This makes it an important crop from an economic as well as food security perspective. Selection of high-quality cultivars and consistent trait enhancement for such cultivars is crucial, and in light of new challenges from climate change, this has become an absolute necessity of time. In this regard, we conducted a detailed qualitative and quantitative trait analysis for multiple commercially viable varieties of wheat, and corresponding results were subjected to a series of critical statistical analyses. Final results have shown that five cultivars including Uqaab-2000, Faisalabad- 85, Anmol-19, NARC-2009, and Pirsabak-2004 depicts higher levels of various essential qualitative and quantitative traits (including Starch content, grain weight, RS content, Protein content, etc.) and are most viable varieties for further growth and trait enhancements to meet regional and global food challenges. 相似文献
39.
Objective: Obese children are stigmatized in same‐sex relationships. This study examines whether, in adulthood, obesity stigma exists in adults when they are asked to rank order preferences for a sexual partner. Research Methods and Procedures: Following the methods of Richardson et al. (Richardson SA, Goodman N, Hastorf AH, Dornbusch SM. Cultural uniformity in reaction to physical disabilities. Am Sociol Rev. 1961;26:241–247) and Latner and Stunkard (Latner J, Stunkard AJ, Wilson GT. Age, ethnic and gender differences in stigmatization of obesity. Orlando, FL: International Conference on Eating Disorders; 2004), 449 college students were asked to rank order six drawings of potential sexual partners. The drawings included an obese partner, partners with various other disabilities, and a healthy partner. Results: The least‐preferred partners were obese. Men, compared with women, provided significantly lower ranks for obese partners (U = 20, 180.00, z = ?2.84, p = 0.01). Discussion: Despite the fact that the majority of adults in the U.S. are overweight, discrimination on the basis of weight occurs in making a choice of a sexual partner. Males particularly make choices of partner based on their weight. Obesity stigma may specifically affect women in sexual relationships. Weight‐related stigma needs to be addressed in the treatment of binge eating disorder or weight management. Finding ways to change attitudes and behavior toward the overweight is a goal for future research in the area. 相似文献
40.
Jarle Tryti Nordeide 《Journal of fish biology》2020,96(2):288-296
This paper highlights possible effects of physical and chemical mechanisms of formalin fixation and preservation on biological tissue and reviews the consequent potential inaccuracies on estimates of body mass of small fishes fixed and preserved in formalin. Twenty-six papers including 65 independent experiments with 35 species which examine effects of formalin on body mass estimates on small fishes are included. The effect of the formalin on the specimens depends on the salinity of the water used to dilute the commercial formalin (usually 1:9 formalin: water) before being used to fixate and preserve fish. Mean wet body mass of the specimens from the studies using seawater or fresh water diluted formalin deceases by 13% and increases by 7%, respectively, from before to after being immersed in formalin. The same trend is found with condition factor in the few papers that report this parameter. Body length decreases on average by c. 2% in fixated and preserved fish regardless of whether the formalin is diluted in seawater or fresh water. 相似文献