The acoustical performance analysis of bilkent amphitheater: Proposal for acoustical renovation

The 4000 seat multi-purpose Bilkent Amphitheater is a semi-dosed amphitheater with a volume of 90,000 m3, designed to serve the University's and the city's educational and artistic activities. At the beginning, the amphitheater was designed only for open-air performances. Afterwards it was decided it would be roofed with a tensile membrane in order to protect the spectators from atmospheric effects. However, the covered amphitheater was turned into a resounding and a problematic place widi a reverberation time of more than 6 s. when the hall is unoccupied. Acoustical interventions were implemented, but these have not been sufficient in decreasing the number of problematic echoes and dead spots. This paper analyzes the hall by means of assessing the fundamental acoustical parameters for both speech and music. Parameters such as reverberation time, early decay time, clarify, definition, lateral fraction, strength and speech transmission index were calculated by the aid of ODEON Room Acoustics Program simulation software Version 6.01. It was observed that most of the parameters are out of the optimum range, and that the sound focused strongly in some locations. After further acoustical renovation of the hall, the distribution of sound became more homogenous as measures of most of the parameters fell into reasonable ranges. © 2006 University of Sydney. All rights reserved

The acoustical characteristics of the Kocatepe Mosque in Ankara, Turkey

This research investigates the acoustical characteristics of mosques of the classical Ottoman period and the contemporary period. Kocatepe Mosque, the major mosque in Ankara, Turkey, as a case from the contemporary era is a unique combination of 16th century Ottoman aesthetics and 20th century technology. Although previous and recent mosques have been inspired by this combination, the use of a reinforced concrete dome without cavity resonators could cause long reverberation times especially in low frequencies. The purpose of this study was to investigate this condition by studying Kocatepe Mosque. The acoustical characteristics of the mosque were analyzed by computer simulation. Objective room-acoustic indicators including reverberation time (RT), early decay time (EDT), clarity (C80), definition (D50), lateral fraction (LF), speech transmission index (STI) and strength (G) are presented. The results show that the acoustical quality of Kocatepe Mosque is not optimal when it is empty, and closest to optimal conditions when fully occupied. The new techniques to overcome excessive low frequency attenuation caused by huge concrete shells of today's mosques are discussed in conclusion. © 2008 University of Sydney. All rights reserved

Redundant functions of RIM1a and RIM2a in Ca 2 þ -triggered neurotransmitter release

a-RIMs (RIM1a and RIM2a) are multidomain active zone proteins of presynaptic terminals. a-RIMs bind to Rab3 on synaptic vesicles and to Munc13 on the active zone via their N-terminal region, and interact with other synaptic proteins via their central and C-terminal regions. Although RIM1a has been well characterized, nothing is known about the function of RIM2a. We now show that RIM1a and RIM2a are expressed in overlapping but distinct patterns throughout the brain. To examine and compare their functions, we generated knockout mice lacking RIM2a, and crossed them with previously produced RIM1a knockout mice. We found that deletion of either RIM1a or RIM2a is not lethal, but ablation of both a-RIMs causes postnatal death. This lethality is not due to a loss of synapse structure or a developmental change, but to a defect in neurotransmitter release. Synapses without a-RIMs still contain active zones and release neurotransmitters, but are unable to mediate normal Ca 2 þ -triggered release. Our data thus demonstrate that a-RIMs are not essential for synapse formation or synaptic exocytosis, but are required for normal Ca 2 þ -triggering of exocytosis

The impacts of occupational risks and their effects on work stress levels of health professional (The sample from the Southeast region of Turkey)

OBJECTIVES: This study was performed to determine the occupational risks and their effects on the work stress of the health professionals working in state hospitals in the Southeast of Turkey. METHODS: This cross-sectional and descriptive study was composed of 360 health professionals of the Pazarcık, Ergani, and Şehitkamil State Hospitals between December 2014 and January 2015. The data of the study were obtained by performing the survey which was composed of questions related to the socio-demographic characteristics, factors that were thought to affect the occupational risks and job stress, as well as, the questions of the Work Stress Scale. The analyses of the data have been performed using Student’s t test and one-way analysis of variance. RESULTS: The working hours, the number of being on-duty, insomnia, and burnout in health professionals were determined to be with the highest mean scores among other stressful risks and hazards. The mean work stress level, which increases the success by creating the group-stimulus effect, was indicated as 2.4 and 2.5 for the health professionals in Pazarcık and Ergani State Hospital, respectively. However, the stress level which poses a threat for the group-health and efficiency was found to be 4.0 for the health professionals of the Şehitkamil State Hospital. CONCLUSIONS: As the exposure of the occupational risks increases in the health professionals, the work stress scores also increase (p < 0.05). The occupational risks and work stress of the health professionals in the Şehitkamil State Hospital should be evaluated in terms of occupational health and safety