If you’ve ever found yourself struggling under a heavy pile of suitcases at the end of a holiday, spare a thought for the porters in some of the planet’s most remote locations. ‘When you start looking around, professional porters all around the world carry loads supported by their heads’, says Norman Heglund, from the Université catholique de Louvain, Belgium, who is fascinated by the technique...

Amino acid/K+ symport (cotransport) across a model epithelium, the lepidopteran midgut, is energized by an electrogenic H+ V-ATPase (H+ pump) in parallel with an electrophoretic K+/H+ antiporter (exchanger). Attempts to analyze this process using well-known equilibrium thermodynamic equations (Nernst, Gibbs), diffusion equations (Nernst, Planck, Einstein, Goldman, Hodgkin, Katz) and equations b...

The purpose of this paper was to address the working conditions tourist porters in Kilimanjaro Region, Tanzania. study employed cross-sectional research design. Since actual number unknown by time data collection, researchers randomly sampled 141 who were willing participate study. collection tools included a questionnaire with both open-ended and closed-ended items face-to-face semi-structured...

Different classes of molecular motors, "rowers" and "porters," have been proposed to describe the chemomechanical transduction of energy. Rowers work in large assemblies and spend a large percentage of time detached from their lattice substrate. Porters behave in the opposite way. We calculated the number of myosin II cross bridges (CB) and the probabilities of attached and detached states in a...

Activity of a Na+/H+ antiporter has been suggested to be critically involved in pH homeostasis in obligately alkalophilic bacteria (Krulwich, K. A., Mandel, K. G., Bornstein, R. F., and Guffanti, A. A. (1979) Biochem. Biophys. Res. Commun. 91, 58-62) and in Escherichia coli (Zilberstein, D., Padan, E., and Schuldiner, S. (1980) FEBS Lett. 116, 177-180). A concern with respect to these proposals...