This paper presents a model of the thermoregulation system of the spadix of skunk cabbage Symplocarpus foetidus which regulates its internal temperature at around $20\phantom{\rule{0.2em}{0ex}}\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}$ during flowering even when the ambient air temperature drops below freezing. From the temperature responses of the spadix to changing ambient air temperature, we assumed that the thermoregulation system of the spadix is probably one of negative feedback control. The feedback signals are based on the rate of temperature change of the spadix over time. A signal is factored into the biochemical energy generator, and becomes biochemical energy, some of which becomes heat. Comparing our proposed model temperature responses and those of the living spadix, we found good agreement. In the process of engineering the model, the existence of two regulatory pathways in the thermoregulation system was simulated, and our proposed model appears to provide the necessary elements to explain the fundamental mechanism of the thermoregulation system of S. foetidus.
Deformation by bending of Si or Si-SiO2 wafers was achieved by sputter deposition of tantalum films. Strains induced at Si-SiO2 interface and in Ta films were investigated using a combination of x-ray diffraction, electron diffraction, and transmission electron microscopy. Thin Ta film deposits had predominantly a fcc structure, while thicker films had the normal bcc structure with certain admixture of fcc. Film strains generated by the coexistence of the polymorph structure were accommodated by formation of misfit dislocations at the film-Si substrate interface. The effect of the induced stress on the electronic parameters characterizing the Si-SiO2 interface was studied in the metal-oxide-semiconductor structure and for the effect on photovoltaic response a metal-insulator-semiconductor solar cell configuration was used. Large changes with increasing stress were observed in the values of recombination time, capture cross section, diffusion length, and in sharply decreased conversion efficiency, fill factor, open-circuit voltage, and short-circuit current.
Currently, there is a strong need to establish a clinical competency evaluation along with associated criteria, taking into consideration the international trend of quality assurance in higher education promoted in Europe, the United States, and Japan. This is based on the global standards proposed by the World Federation for Medical Education. Cross-sectional studies for each period have been reported regarding education at the pre-graduate clinical practical training and post-graduate clinical training levels. However, no studies on a clinical competency examination as an overall evaluation at the end of pre-graduate clinical practical training and at the end of post–graduate clinical training, or sequential evaluations on pre- and post-graduate dental education have ever been conducted. We report the results of a pilot study on the correlations within the post-graduate clinical competency evaluation as well as the results of comparative examinations between pre-graduate objective structured clinical achievement tests. The objective of this pilot study was to establish an appropriate clinical competency evaluation for professionalism in dental education. An examination was administered to dental trainees at the end of their clinical training. Analysis of the individual evaluation scores indicated a significant correlation with the post-graduate psychomotor domain. The correlation between the total score for postgraduate assignments and the post-graduate prosthetic dentistry score was high. The correlation between the individual evaluation scores for pre- and post-graduate assessment indicated no significant correlation. The present study found no correlation between the evaluations for the same item in the same subject over time before and after graduation,whereas a correlation was observed with the evaluation of the items in the psychomotor domain after postgraduate clinical training. The specific item may represent the entire assessment.
Tobacco (Nicotiana tabacum L. cv. BY-2) cell lines tolerant to 700 μM Ni in which unselected cells can not grow, were selected. The Ni-tolerant cells were also more tolerant to Co, but not to Cd than unselected cells. Ni concentrations in Ni-tolerant cells were always higher than those in medium. Since buthionine sulfoximine did not affect their Ni-tolerance, it is suggested that phytochelatins are not involved in Ni-tolerance of Ni-tolerant cells. On the other hand, histidine contents in Ni-tolerant and unselected cells, which were treated with Ni, were higher that those treated without Ni, and the degree of the elevation of histidine contents by Ni-treatment was higher in Ni-tolerant cells than in unselected cells. Additionally, exogenous histidine reduced the inhibitory effect of Ni on the growth of unselected cells. In addition, the cells that were tolerant to histidine-analogue, had higher contents of histidine and Ni-tolerance. These results suggest that histidine is involved in Ni-tolerance and the detoxification of Ni in symplast in Ni-tolerant cells.
