A Modified Underwater Weighing Method Without Complete Immersion

This study was designed to examine the validity of a modified underwater weighing method for measuring human body volume (BV) that does not require head submersion (MUW). Results were compared with those obtained by the underwater weighing method (UW). The true head volume was calculated from the difference in BV, with and without head submersion. Stepwise regression analysis provided an equation to predict the head volume (HV) from the head girth (HG), the head length (HL), the head breadth (HB), the neck girth (NG), the face length I (FLI), the face length II (FLII), and the cheek girth. The equation for males was HV=0.185^*(HG) +0.122^*(FLII) -8.925, r^2=0.678, SEE=0.216. The equation for females was HV=0.131^*(HG) -0.026^*(NG) +0.112^*(FLI) -6.760, r^2=0.747, SEE=0.154. Cross-validation of predicted HV showed that the correlation coefficients were r=0.759, SEE=0.193 and r=0.749, SEE=0.193, for males and females respectively. Correlation coefficients and SEE between MUW and MW for body volume and % body fat were r=1.000, SEE=0.207 and r=0.983, SEE=1.339 for males and r=1.000, SEE=0.196 and r=0.946, SEE=1.915 for females. It can be concluded that this new method offers promising possibilities for future research with people who are unable to submerge their heads

Effect of Plant Hormones on Tobacco Mosaic Virus Concentration in Tobacco Tissue Culture

Tobacco mosaic virus (TMV) concentrations in tobacco callus tissues grown on the media containing cu-naphthaleneacetic acid (NAA) and kinetin at different concentrations were assayed periodically during successive cultures. Tobacco callus originally raised from the TMV-infected tobacco stem became green and compact when serially cultured on the medium containing lower concentration (0.01-o. 1 mg/l) of NAA or higher concentration (2mg/l) of kinetin. Translucent and soft callus was obtained at higher concentration (l-40 mg/l) of NAA or lower concentration (O-O. 2 mg/l) of kinetin. Microscopic observations of the thin sectioned callus tissues revieled that the green colored compact tissue was composed of the closely associated small cells and many tracheid-like structures, while in the translucent and soft tissue, large cells were roughly arranged showing less association and no tracheidlike structure was found. TMV was maintained at high concentration in the compact callus during successive cultures, however, it was no longer detected beyond the third generation (90 days) in the translucent soft callus grown under the optimum hormone balances. Since both hormones do not have direct inactivation effect on TMV, the results suggest that TMV multiplication in the callus tissue closely corresponds with the cell arrangement of the tissue, which is considerably affected by hormone balances in the media

Effect of Plant Hormones on Tobacco Mosaic Virus Concentration in Tobacco Tissue Culture

Tobacco mosaic virus (TMV) concentrations in tobacco callus tissues grown on the media containing cu-naphthaleneacetic acid (NAA) and kinetin at different concentrations were assayed periodically during successive cultures. Tobacco callus originally raised from the TMV-infected tobacco stem became green and compact when serially cultured on the medium containing lower concentration (0.01-o. 1 mg/l) of NAA or higher concentration (2mg/l) of kinetin. Translucent and soft callus was obtained at higher concentration (l-40 mg/l) of NAA or lower concentration (O-O. 2 mg/l) of kinetin. Microscopic observations of the thin sectioned callus tissues revieled that the green colored compact tissue was composed of the closely associated small cells and many tracheid-like structures, while in the translucent and soft tissue, large cells were roughly arranged showing less association and no tracheidlike structure was found. TMV was maintained at high concentration in the compact callus during successive cultures, however, it was no longer detected beyond the third generation (90 days) in the translucent soft callus grown under the optimum hormone balances. Since both hormones do not have direct inactivation effect on TMV, the results suggest that TMV multiplication in the callus tissue closely corresponds with the cell arrangement of the tissue, which is considerably affected by hormone balances in the media