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91.
92.
Teachers are frequently cited as experiencing a high rate of vocal dysfunction (1-7). Despite considerable research in the area of voice problems in teachers, the prevalence of voice disorders in this group is unknown. This study investigated the prevalence of self-reported voice problems in teachers using a mail survey of a simple random sample of 1168 state school teachers (preschool-Grade 12) in South Australia. As part of the survey, teachers were asked to report voice problems for the day of the survey, during the current teaching year, and during their careers. The response rate was 75%, with 16% of teachers reporting voice problems on the day of the survey, 20% reporting problems during the current teaching year, and 19% reporting problems at some time during their career. Females were twice as likely as males to report voice problems. These findings clearly indicate a need for further investigation of the causes of vocal dysfunction in teachers and for the development of educational programs aimed at preventing voice problems in this group of professional voice users. 相似文献
93.
This is an ECG of a 6-year-old girl. She presented to us for management of epilepsy. Magnetic resonance imaging (MRI) of the brain showed multiple lesions consistent with cortical and subcortical tubers. There were also achromic spots on her skin and echocardiography demonstrated a rhabdomyoma near the right ventricular outflow tract. A diagnosis of tuberous sclerosis, an autosomal-dominantly inherited condition, was made. What is abnormal about the ECG? 相似文献
94.
CW van Haselen PV Diederen J Toonstra SC van der Putte LH Rademakers JA Faber WA van Vloten 《Canadian Metallurgical Quarterly》1998,290(11):583-590
Small-cell variants of Sézary syndrome and mycosis fungoides (MF) have been described. However, in these studies the nuclear area of the small-cell variant of MF (SC-MF) as compared to histological classical MF (CL-MF) was not characterized objectively by quantitative electron microscopy. In a 14-year follow-up period, of a total of 76 patch/plaque stage MF patients seen in the Department of Dermatology of the University Hospital Utrecht, 14 (18%) had an infiltrate composed of atypical lymphocytes characterized by a distinctly smaller cell diameter and smaller, hyperchromatic, deeply indented nuclei as compared to the usual cell type of MF. The aim of the investigation was to confirm this observation objectively using quantitative electron microscopy (morphometry) and to define SC-MF as compared to CL-MF. The study was performed on the 14 patients with SC-MF, and 10 patients with clinical and histological CL-MF and 4 patients with chronic eczema. Electron micrographs of sections obtained from each biopsy were analysed by computer to produce the following data: a nuclear contour index (NCI), the mean nuclear area (MNA), the mean nuclear area of the cells above the 75th percentile (P75NA) and the percentage of cells larger than 30 microm2. The values of MNA differed significantly between patients with SC-MF and those with CL-MF (17.6 vs 23.2 microm2; P = 0.02), as did the values of P75NA (20.7 vs 27.9 microm2; P = 0.01). The NCI of the SC-MF and CL-MF patients were similar. These results are consistent with our observations that SC-MF does indeed exist. 相似文献
95.
Analyzed the film Three Approaches to Psychotherapy (E. L. Shostrom, 1966), which depicts C. Rogers (client-centered therapy), A. Ellis (rational-emotive therapy), and F. S. Perls (Gestalt therapy) interviewing the same client, Gloria. Verbal exchanges between participants were analyzed, using T. S. Essig and R. L. Russell's (1988) categories for analyzing psychological relations between subjects and events in discourse. Predictable patterns in how therapists of different theoretical orientations represent subjectivity in discourse can be screened with these categories. Classification categories are appended. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
96.
Valerie Shute Seyedahmad Rahimi Ginny Smith Fengfeng Ke Russell Almond Chih-Pu Dai Renata Kuba Zhichun Liu Xiaotong Yang Chen Sun 《Journal of Computer Assisted Learning》2021,37(1):127-141
In this study, we investigated the validity of a stealth assessment of physics understanding in an educational game, as well as the effectiveness of different game-level delivery methods and various in-game supports on learning. Using a game called Physics Playground, we randomly assigned 263 ninth- to eleventh-grade students into four groups: adaptive, linear, free choice and no-treatment control. Each condition had access to the same in-game learning supports during gameplay. Results showed that: (a) the stealth assessment estimates of physics understanding were valid—significantly correlating with the external physics test scores; (b) there was no significant effect of game-level delivery method on students' learning; and (c) physics animations were the most effective (among eight supports tested) in predicting both learning outcome and in-game performance (e.g. number of game levels solved). We included student enjoyment, gender and ethnicity in our analyses as moderators to further investigate the research questions. 相似文献
97.
Effects of early-postmortem glycolytic rate on beef tenderness 总被引:1,自引:0,他引:1
Electrical stimulation (ES) was applied at 500 V to one side from each of 60 beef carcasses at 30 to 40 min postmortem. Wide ranges of early-postmortem glycolytic and cooling rates were produced in the musculature by use of three different forms of ES (in addition to non-ES treatment of the contralateral sides) and application of chilling routines of four different degrees of severity. Panel and Warner-Bratzler shear evaluations of loin steaks from all 120 sides showed that tenderness was highest when glycolysis had proceeded at an intermediate rate (corresponding to the attainment of a 3-h pH of about 6·1) and was appreciably lower on both sides of this mid-value. The toughening effect of rapid glycolysis (relative to that of a moderately increased glycolytic rate) persisted through 14 days of aging at 2°C.
These observations appear to be incompatible with the view that lysosomal enzymes contribute significantly to ES-induced tenderization. They also indicate that the effect of ES on tenderness is highly dependent on the subsequent cooling rate, very slow chilling sometimes accelerating the already high rate of pH fall to such an extent that the tissue is significantly toughened. Finally, they suggest that the goal of maximizing the early-postmortem rate of pH decline in bovine muscle is misguided and, if attained, will cause sub-optimal tenderness. 相似文献
98.
Novel imide-aryl ether benzoxazole copolymers were prepared and their morphology and mechanical properties investigated. A key feature of these copolymers is the incorporation of a benzoxazole moiety by the use of 2,2′-bis[4-(3-aminophenoxy)phenyl]-6,6′-bibenzoxazole or 2,2′-bis[4-(4-aminophenoxy)-phenyl]-6,6′-bibenzoxazole as co-diamines in polyimide syntheses. The preparation of these diamines involved the nucleophilic aromatic substitution of 2,2′-bis(4-fluorophenyl)-6,6′-bibenzoxazole with either 3- or 4-aminophenol in the presence of K2CO3. The diamines were co-reacted with various compositions of pyromellitic dianhydride (PMDA) and 4,4′-oxydianiline (ODA) to synthesize the desired poly(amic acids). Films were cast and cured (350°C) to effect the imide formation, affording films with elongations between 40 and 110% and moduli in the 2000–2750 MPa range. The copolymers exhibited good dimensional (Tg in excess of 300°C) and thermal stability. Wide-angle X-ray diffraction measurements on the copolymers showed that the ordered morphology characteristic of PMDA/ODA polyimide was retained. Improvements in the auto-adhesion were observed, particularly in those copolymers which displayed a Tg. 相似文献
99.
Laura M. Russell Lloyd F. Johnson D. P. H. Hasselman Robert Ruh 《Journal of the American Ceramic Society》1987,70(10):226-C
The thermal conductivity and diffusivity of silicon carbide whisker reinforced mullite was shown to increase with whisker content. This effect was much greater for vapor-liquid-solid (VLS) whiskers than for rice-hull (RH) whiskers. This suggests that the thermal conductivity for the VLS whiskers was significantly higher than for the RH whiskers. Due to preferred orientation of the whiskers, thermal conductivity and diffusivity of the composite samples exhibited significant anisotropy. 相似文献
100.