Provo City Corp. v. Donna I. Knudsen : Brief of Respondent

Appeal from the Judgment of the Fourth District Court. The Honorable J. Robert Bullock

Power efficiency of outer hair cell somatic electromotility

© 2009 Rabbitt et al. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in PLoS Computational Biology 5 (2009): e1000444, doi:10.1371/journal.pcbi.1000444.Cochlear outer hair cells (OHCs) are fast biological motors that serve to enhance the vibration of the organ of Corti and increase the sensitivity of the inner ear to sound. Exactly how OHCs produce useful mechanical power at auditory frequencies, given their intrinsic biophysical properties, has been a subject of considerable debate. To address this we formulated a mathematical model of the OHC based on first principles and analyzed the power conversion efficiency in the frequency domain. The model includes a mixture-composite constitutive model of the active lateral wall and spatially distributed electro-mechanical fields. The analysis predicts that: 1) the peak power efficiency is likely to be tuned to a specific frequency, dependent upon OHC length, and this tuning may contribute to the place principle and frequency selectivity in the cochlea; 2) the OHC power output can be detuned and attenuated by increasing the basal conductance of the cell, a parameter likely controlled by the brain via the efferent system; and 3) power output efficiency is limited by mechanical properties of the load, thus suggesting that impedance of the organ of Corti may be matched regionally to the OHC. The high power efficiency, tuning, and efferent control of outer hair cells are the direct result of biophysical properties of the cells, thus providing the physical basis for the remarkable sensitivity and selectivity of hearing.This work was supported by NIDCD R01 DC04928 (Rabbitt), NIDCD R01 DC00384 (Brownell) and NASA Ames GSRA56000135 (Breneman)

Satisfaction with child health services in the non-government sector of Hong Kong: Consumer evaluation

There is increasing emphasis on community-based health care. Evaluation of both government and non-government maternal and child care services in Hong Kong is a key objective for future development. The Kwun Tong Community Health Project, one of the Government's subsidy services, aim is to help in the rapid growth of the community so as to recognize needs, and to resolve health care issues. The present paper examines the findings of a consumer evaluation of three community health centers in the Kwun Tong Community Health Project, regarding clients' satisfaction towards the accessibility, information, use, medical consultation, perceptions of health problems of infants and cost of services provided. There was overall satisfaction expressed by the clients regarding health maintenance officers and the services provided. Provision of comprehensive family-focused care, including child and women's health was highly recommended. Parents' participation in decision-making about care and discussion about the child's health care plan were recognized as important issues to consider. Provision of play facilities and more flexible hours of operation were found to be beneficial in improving client's satisfaction. Finally, continuing education of the health maintenance officers was recognized as pertinent for them to update their knowledge while providing health education to the clients.link_to_subscribed_fulltex