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Theoretical vibrational spectra of polypyrrole are presented, based on a single-periodic-chain model and harmonic potential in-plane and out-of-plane parameters transferred from the pyrrole molecule. The infrared-absorption intensities were included in the calculations for the first time in polypyrrole. Experimental spectra are analyzed and compared with theoretical ones. Some modes in the experimental spectra indicate the presence of nonplanar conformation. Also, Raman frequencies were compared with experimental ones. Significant effects of electron–phonon coupling are absent. © 1995 American Institute of Physics. [ABSTRACT FROM AUTHOR]

This study aimed to determine the effects of two different programs of modern sports dancing on coordination, strength, and speed in 60 beginner-level female dancers, aged 13 and 14 yrs. The subjects were divided into two experimental groups (E1 and E2), each numbering 30 subjects, drawn from local dance clubs. In order to determine motor coordination, strength, and speed, we used 15 measurements. The groups were tested before and after the experimental programs. Both experimental programs lasted for 18 wks, with training sessions twice a week for 60 minutes. The subjects from the E1 group trained according to a new experimental program of disco dance (DD) modern sports dance, and the E2 group trained according to the classic DD program of the same kind for beginner selections. The obtained results were assessed by statistical analysis: a paired-samples t-test and MANCOVA/ANCOVA. The results indicated that following the experimental programs, both groups showed a statistically significant improvement in the evaluated skills, but the changes among the E1 group subjects were more pronounced. The basic assumption of this research was confirmed, that the new experimental DD program has a significant influence on coordination, strength, and speed. In relation to these changes, the application of the new DD program was recommended for beginner dancers. [ABSTRACT FROM AUTHOR]

Various dance techniques and performances have different effects on the biomechanics of the body and may lead to different injury profiles. Few studies have analyzed the risk of injury associated with particular types of dance, especially in adolescents when accelerated growth compounds the risk of injury. Ninety-six female dancers with international competitive dance experience from four Balkan European countries were selected from a population of 347 adolescent dancers for this study. Their average age was 13.8 yrs (range, 12 to 16). The subjects were divided into four groups according to their dance styles: cheerleading, dance show, disco dance, and standard and Latin dance. The first aim of the study was to identify differences between the various dance style groups in body mass index (BMI) and dance sport involvement. According to Wilks test (one-way MANOVA), there was a significant multivariate effect (F = 13.8; p < 0.001) between the four dance groups. The dancers belonging to the disco group started systematic training earlier than the other dancers, the standard and Latin dancers practiced the most intensively, and the show dancers had considerably lower BMI than the disco dancers. The second aim of the study was to define the pain status in 14 body regions for dancers in the various dance styles by monitoring their pain status with the SEFIP questionnaire. The most common locations for pain were the calves (43.7%), knees (32.7%), and ankles (27.2%). According to the X2 test, cheerleading dancers reported a significantly higher frequency of knee injuries, and standard and Latin dancers reported a significantly higher frequency of toe injuries. The specific way in which some dance disciplines are practiced and their dance techniques do induce characteristic injuries. [ABSTRACT FROM AUTHOR]

Very few studies have been conducted on substance use (SU) in performing sports. In the current study, we analyzed SU and factors related to SU in dance sport. The sample subjects consisted of 21 female and 22 male dancers, all >19 years of age, who were given an anonymous questionnaire developed for this study. The questionnaire consisted of questions about 1) social, cultural, educational, and sport-related factors, and 2) SU, including alcohol, opiates, cigarettes, and doping consumption, and personal opinions. The chi-square test was used to define the differences between male and female dancers. To identify the relationships between the studied factors and SU, the Pearson¿s correlation coefficient was calculated separately in males and females. We found a relatively low incidence of cigarette smoking (<10%) and significant differences between males and females in opinions regarding doping issues. The level of the sport achievement in females and religiousness in male dancers was significantly related to SU. Although not frequent, the consumption of alcohol was more common in more successful and experienced dancers. The use of pain killers was related to age in female dancers (all at p < 0.05). Based on these results, we recommend educational programs regarding SU, especially about doping problems, in sport dance. [ABSTRACT FROM AUTHOR]

Abstract: We have synthesized CdS and Cd0.7Mn0.3S nanocrystals with diameters of about 4.5nm. These materials have been studied using photoluminescence spectroscopy with various excitation energies in the temperature range from 1.8 to 300K. We registered surface and defect states as well as two Mn2+ energy levels that correspond to Mn2+ ions in two different crystal environments. In addition, the resonant behavior of one Mn state excited by 514.5nm wavelength of laser light has been clearly observed in obtained spectra. We proposed the scheme of energy levels and transitions that explain obtained experimental results. [Copyright &y& Elsevier]

Although religiousness is found to be a significant protective factor in substance use, there is an evidential lack of studies of such in athletes. The aim of the study was to identify the predictive value of the religiousness and some social, educational, and sport factors on substance use in 43 sport dancers. An originally developed questionnaire for studying substance use and precipitation factors was applied. The Chi-square showed male dancers as more religious than females. Using the Spearman's correlation, religiousness was found to be a significant protective factor in cigarette smoking, sport nutritional supplementation, and the likelihood of doping. Data were interpreted emphasizing the previous findings from the literature.