Effect Of changes in sodium intake on cell transport parameters

Changing sodium intake from 70-200 mmol/day elevates blood pressure in normotensive volunteers by 6/4 mmHg. Older people, people with reduced renal function on a low sodium diet and people with a family history of hypertension are more likely to show this effect. The rise in blood pressure was associated with a fall in plasma volume suggesting that plasma volume changes do not initiate hypertension. In normotensive individuals the most common abnormality in membrane sodium transport induced by an extra sodium load was an increased permeability of the red cell to sodium. Some normotensive individuals also had an increase in the level of a plasma inhibitor that inhibited Na-K ATPase. These individuals also appeared to have a rise in blood pressure. Sodium intake and blood pressure are related. The relationship differs in different people and is probably controlled by the genetically inherited capacity of systems involved in membrane sodium transport.

Nedd4-2(NEDD4L) controls intracellular Na(+)-mediated activity of voltage-gated sodium channels in primary cortical neurons.

Nedd4-2, a HECT (homologous with E6-associated protein C-terminus)-type ubiquitin protein ligase, has been implicated in regulating several ion channels, including Navs (voltage-gated sodium channels). In Xenopus oocytes Nedd4-2 strongly inhibits the activity of multiple Navs. However, the conditions under which Nedd4-2 mediates native Nav regulation remain uncharacterized. Using Nedd4-2-deficient mice, we demonstrate in the present study that in foetal cortical neurons Nedd4-2 regulates Navs specifically in response to elevated intracellular Na(+), but does not affect steady-state Nav activity. In dorsal root ganglia neurons from the same mice, however, Nedd4-2 does not control Nav activities. The results of the present study provide the first physiological evidence for an essential function of Nedd4-2 in regulating Navs in the central nervous system.

Transport simulation : beyond traditional approaches

In recent years, the transport simulation of large road networks has become far more rapid and detailed, and many exciting developments in this field have emerged. In this perspective, the authors describe the simulation of automobile, pedestrian and rail traffic, coupled to new applications, such as the embedding of traffic simulation into driving simulators, to give a more realistic environment of driver behavior surrounding the subject vehicle.

Evaluating equal employment opportunity and its impact on the increased participation of men and women in the transport industry

This paper seeks to identify the approaches undertaken in implementing equal employment opportunity in the transport industry in Australia and the links between these approaches and indicators of increased participation of women. This male dominated industry employs limited numbers of women with fewer numbers of women in management. The study analyses data from a unique set of equal opportunity progress reports from all organisations in the transport industry that are required to provide public reports under Australian legislation. The findings indicate a correlation between some approaches to equal opportunity and increased numbers of women in some areas. The study is equally remarkable for what it does not find. Despite widespread equal opportunity implementation across a broad number of employment measures there are limited measures that predict increases in the numbers of women in management or in non-traditional roles. This study differs from others in that it identifies issues specific to one industry and links organisational approach to equal opportunity with the employment status of both women and men.

Is there a future for non-motorized public transport in Asia?

Non-motorized public transport (NMPT), especially three-wheeler cycle rickshaws, has a long history in East Asia; and has long been a major transport planning issue. Policy measures to restrict or eliminate NMPT have already been implemented in many developing cities with mixed success. However given the economic, social and cultural significance of NMPT, its environmental benefits, and the magnitude of its role in sustaining the mobility needs of citizens, it is timely to reconsider the future role of NMPT. Rather than pursuing policies to eliminate NMPT, a better approach may be to integrate motorized and non-motorized vehicles as complementary rather than competitive forces. With this backdrop and given the international significance of the problem, this paper examines the current role and significance of NMPT using Dhaka as a case study, and sets a research agenda for the future of NMPT in a sustainable transport system.