Neues von der Nervenzellmembran

Information processing in the brain requires the activation of electrically and chemically gated ion channels in the neuronal plasma membrane. Recently, the function and the molecular composition of some of these membrane proteins have become the subject of extensive biochemical and biophysical analysis. From the currently available data, it is proposed that the architecture of different neuronal ion channels obeys common structural principles which may have resulted from a divergent evolution of a limited number of ancestor transmembrane polypeptides.     

Investigations on the simultaneous uptake and release of mercury by Dunaliella tertiolecta

By using two different radioactive mercury isotopes, detailed information was obtained on the uptake and simultaneous release of mercury by Dunaliella tertiolecta. Hg-203 was added to a well-aged culture, which 2 days later was separated from the medium, washed and cultivated again in a fresh medium containing Hg-197. It was found that an exchange of mercury takes place between the cells and the medium. An increase in the concentration of volatile mercury occurs simultaneously with the maximum concentration of chlorophyll a. Comparing the culture solutions with the blanks, the dissolved mercury shows similar volatility. This leads to the assumption that the main part of the dissolved mercury in the culture solutions is in the inorganic state.     

“Are you still driving?” Metasynthesis of patient preferences for communication with health care providers

Aim: The aim of this study was to synthesize published qualitative studies to identify older adults' preferences for communication about driving with health care providers.

Background: Health care providers play a key role in addressing driving safety and driving retirement with older adults, but conversations about driving can be difficult. Guides exist for family members and providers, but to date less is known about the types of communication and messages older drivers want from their health care providers.

Design: A qualitative metasynthesis of studies published on or before October 10, 2014, in databases (PubMed, CINAHL, PsycINFO, and Web of Science) and grey literature was performed.

Review Methods: Twenty-two published studies representing 518 older adult drivers met the following inclusion criteria: the study (1) was about driving; (2) involved older drivers; (3) was qualitative (rather than quantitative or mixed methods); and (4) contained information on older drivers' perspectives about communication with health care providers.

Results: We identified 5 major themes regarding older adults' communication preferences: (1) driving discussions are emotionally charged; (2) context matters; (3) providers are trusted and viewed as authority figures; (4) communication should occur over a period of time rather than suddenly; and (5) older adults desire agency in the decision to stop driving.

Conclusion: Various stakeholders involved in older driver safety should consider older drivers' perspectives regarding discussions about driving. Health care providers can respect and empower older drivers—and support their family members—through tactful communication about driving safety and mobility transitions during the life course.     

Aerobe Gärung und Äthanol-Umsatz

The Science of Nature -     

A Contingent Trip Model for Estimating Rail-trail Demand

The authors develop a contingent trip model to estimate the recreation demand for and value of a potential rail-trail site in north-east Georgia. The contingent trip model is an alternative to travel cost modelling useful for ex ante evaluation of proposed recreation resources or management alternatives. The authors estimate the empirical demand for trips using a negative binomial regression specification. Their findings indicate a per-trip consumer surplus ranging from US$18.46 to US$29.23 and a price elasticity of m 0.68. In aggregate, they estimate that the rail-trail would receive approximately 416 213 recreation visits per year by area households and account for a total consumer surplus in excess of US$7.5 million.