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91.
Adiposity and distribution of body fat are important issues in the prediction of degenerative diseases. Measurements of weight, height, circumferences of thigh, waist and hip; triceps, biceps, subscapular and suprailiac skinfolds; body mass index (BMI), centripetal index (CI), waist/hip (WHR), waist/thigh (WTR) ratios and sigma skinfold thickness (sigma SK) were performed in 836 youths (373 males, 463 females) aged 11, 13 and 15 years. Analysis method included Student t test, ANOVA, Principal Component Analysis and simple linear regression model, with sigma skinfold thickness as independent variable. The sample was divided in two groups (A and B) according with Graffar-Méndez Castellano methodology. Sexual dimorphism in adiposity and differences in body fat distribution were found with a tendency towards peripherical distribution for girls and centripetal for boys. Group A (higher stratum) showed higher values of skinfolds in both trunk and extremities, and a more peripherical distribution than his peers from group B. First component from extremity/trunk and second component from upper/inferior trunk distribution explained 40.2% and 32.7% of the variability respectively. CI and WHR appear dependent from BMI, WHR showed independence from BMI, although significant differences was found by social stratum, reflecting differences in fat topography in boys and girls from group B. These results confirm more adiposity in group A and a tendency towards central distribution in group B. Studies of body fat distribution during these age should include waist/thigh ratio. 相似文献
92.
A technique for determining low critical micelle concentrations (CMC) by means of a hydrophobic fluorescence probe has been
developed. The amount of the fluorescent probe at the CMC is so small that the effect of the probe on micelle formation is
negligible. The fluorescence intensity was measured at fixed dye/surfactant ratios, and it decreased with concentration. A
quantity proportional to fluorescent quantum yield was calculated and found to be high for concentrations of surfactant above
the CMC and almost zero below the CMC, giving a distinct break in the quantum yield vs. the concentration curve. 相似文献
93.
Naziriwo Betty Bbosa Wandiga Shem Oyoo 《Lakes & Reservoirs: Research and Management》2013,18(3):259-273
The current study was conducted for 2 years (2006 and 2007) during January, April and September to investigate seasonal variations in biological parameters and planktonic biodiversity observed at four sampling sites (MRM, M500, SRM and S500) in Lake Victoria. Blue‐green algae (Cyanophyta) dominated the lakeshore waters of Lake Victoria, comprising 54.1% of the total algal content, compared to 24.4% for diatoms and 14.7% for green algae (Chlorophyta). Euglenophytes and dinoflagellates both constitute <10% of the algal biomass. The algal distribution at the Sango Bay sampling sites, however, is different in that it is dominated by diatoms, in contrast to Murchison Bay, which was dominated by blue‐green algae. This study also investigated the influence of iron (Fe2+and Fe3+) and zinc (Zn2+) ions on four strains of microcystis (CYN 464, CYN 465, CYN 478 and CYN 522) isolated from Murchison Bay in Lake Victoria. The suggestion that iron species and zinc ions might limit phytoplankton growth in Lake Victoria was tested by enriching algal culture media with different metal concentrations. Based on measurements of the algal biomass of four species of Lake Victoria, the algal biomass of the four microcystis strains generally decreased with increased zinc and Fe2+ concentrations. The algal biomass of the four strains, however, increased with increased Fe3+ concentrations. This response to different metal concentrations provides evidence that high Zn2+ and Fe2+ ion concentrations limit phytoplankton growth and species distribution. The availability of Fe3+ ions is an important selective force on Lake Victoria phytoplankton communities. 相似文献
94.
Much is known about the removal and reaction mechanisms of the naturally occurring precursors of trihalomethanes such as humic and fulvic acids. However, another class of precursors including phenols, anilines and aliphatic diketones has not been thoroughly investigated. This study shows that these truly soluble, monomeric precursors are poorly removed by alum coagulation. The use of permanganate preceding alum coagulation provides a good reduction of chloroform in water samples containing high proportions of monomeric precursors. The process was found to be less effective for water samples containing a high proportion of humic acid. This is possibly due to the degradation products from the permanganate oxidation of humic acid. These degradation products are not readily removed by alum coagulation and become available for subsequent chloroform formation. 相似文献
95.
96.
Huanmei Wu Becky Norum Betty Salzberg David Kaeli 《Subsurface Sensing Technologies and Applications》2003,4(4):395-408
The CenSSIS Image Database System is a scientific database that enables effective collaboration, scientific data sharing and accelerates fundamental research. We describe a state-of-the-art system that uses the Oracle RDBMS and J2EE technologies to provide remote, Internet-based data access. The system incorporates efficient submission and retrieval of images and metadata, indexing of metadata for efficient searching, and complex relational query capabilities. 相似文献
97.
At 12, 18, and 34 mo after Hurricane Hugo, 831 adults were interviewed regarding their disaster-related stressors and present psychological state. The study's purposes were to assess whether age influenced one's vulnerability to postdisaster stress and to evaluate 4 different perspectives on disaster recovery that have been previously used to explain age differences. Regression analyses demonstrated that disaster exposure had substantial and pervasive psychological effects. The analyses also revealed a curvilinear interaction between disaster exposure and age. Younger Ss exhibited the most distress in the absence of disaster, but middle-aged people did so in its presence. Differential exposure, resources, and inoculation all failed to explain these differences; however, the burden perspective had considerable explanatory power. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
98.
Investigated whether goal-setting theory generalizes to other cultures by looking at the relation between goal setting and output among 92 Caribbean women who performed home-based piecework. Results confirm the hypothesis that setting specific and difficult goals would result in higher performance than no goal or a "do one's best" goal. (5 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
99.
Yung Betty R.; Hammond W. Rodney; Sampson Michelle; Warfield Janeece 《Canadian Metallurgical Quarterly》1998,29(4):398
Although clinical psychology has made strides in developing prevention and intervention strategies to reduce youth violence, there has been little attention to skills-oriented preprofessional training to prepare graduate students for practice roles in this emerging area of public health concern. This article describes a practicum training experience that prepares doctoral-level clinical psychology trainees to serve as youth violence prevention service providers, trainers, and consultants. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
100.
Harold M. Sell Betty M. Taylor Elroy J. Miller 《Journal of the American Oil Chemists' Society》1948,25(11):416-417
Summary A study has been made of the identification of the fatty acids of the fat from a North American black bear. The methyl esters
of the fatty acids from the fat were prepared and fractionated through a Stedman Column. Myristie, palmitic, stearic, oleic,
palmitoleic, and linoleic acids were identified by the melting points of the p-bromophenacyl ester of the saturated acids
and the hydroxy and bromine addition compounds of the unsaturated acids.
Published with the approval of the Director of the Michigan Agricultural Experimental Station as Journal article No. 970 (new
series). 相似文献