Home About us Contact
|
Home About us Contact | ||
|
|
||
Little Account (little + account)
Selected AbstractsTime course of the renal functional response to partial nephrectomy: measurements in conscious ratsEXPERIMENTAL PHYSIOLOGY, Issue 1 2007R. M. Chamberlain Previous investigations into the functional responses of the surviving nephrons following reductions in renal mass have been performed largely in anaesthetized animals and have taken little account of how the compensatory changes develop with time. The present study has assessed a method for determining glomerular filtration rate (GFR) in unrestrained, uncatheterized, conscious rats (plasma disappearance of 99mTc-diethylenetriamene pentaacetic acid (DTPA)) and has used this method to document the time course of the changes in GFR over a 32 day period following uninephrectomy or 5/6 nephrectomy. Concurrent measurements of excretion rates and of the clearance of lithium (the latter being an index of end-proximal fluid delivery) provided information on changes in overall tubular function and segmental reabsorption. After uninephrectomy, the GFR of the remaining kidney (compared with that of a single kidney of sham-operated animals) increased maximally (by ,50%) within 8 days; after 5/6 nephrectomy, the increase in the GFR of the remnant kidney was maximal (at ,300%) within 16 days. Overall excretion rates of sodium and potassium were well maintained in partially nephrectomized animals throughout the period of study, while the excretion of water increased (by ,30% after uninephrectomy and by ,120% after 5/6 nephrectomy), partly as a result of the compensatory increases in GFR but mainly as a consequence of moderate (after uninephrectomy) or marked (after 5/6 nephrectomy) reductions in fractional reabsorption. During the early period after 5/6 nephrectomy, potassium excretion sometimes exceeded the filtered load, indicating net secretion. Lithium clearance data indicated that the changes in tubular function after 5/6 nephrectomy include a reduction in fractional reabsorption in the proximal tubule, whereas after uninephrectomy any such effect on the proximal tubule is minor and transient. [source] Stabilizing flows in the legal field: illusions of permanence, intellectual property rights and the transnationalization of lawGLOBAL NETWORKS, Issue 1 2003Paul Street In this article I examine some of the problems that ,modern' legal theory poses for a consideration of the extended reach of social actors and institutions in time and space. While jurisprudence has begun to engage with the concept of globalization, it has done so in a relatively limited manner. Thus legal theory's encounters with highly visible transnational practices have, for the most part, resulted not in challenging the prevailing formal legal paradigm, but in a renewed if slightly modified search for a general jurisprudence that ultimately takes little account of the manner in which the work of law is carried out transnationally. In the first part of this article I examine how legal theory's concern to maintain its own integrity places limitations on its ability to examine the permeability of social boundaries. In the latter part I draw on critical human geography, post,structuralism and actor,network theory (ANT), to examine the manner in which transnational actors have been able to mobilize law, and in particular intellectual property rights (IPRs), as a necessary strategy for both maintaining the meanings of bio,technologies through time and space, and enrolling farmers into particular social networks. [source] Effects of dietary caffeine on EEG, performance and mood when rested and sleep restricted,HUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 8 2008Michael A. Keane Abstract Rationale: Until recently, little account had been taken of the confounding effects of caffeine withdrawal and withdrawal reversal when examining the net effects of dietary caffeine. Objectives: By including a manipulation involving sleep restriction, the present study aimed to extend recent findings from research in which caffeine withdrawal and withdrawal reversal were controlled. The main aims of the study were to examine the net effects of caffeine, as well as its potential restorative effects following sleep restriction, on EEG, performance and mood. Method: A randomised cross-over design was used in which 15 participants alternated weekly between ingesting placebo and caffeine (1.75,mg/kg) three times daily for four consecutive weeks following either usual sleep or sleep restriction. EEG activity was measured at 32 sites during eyes closed, eyes open and performance of a vigilance task. Results: Modest effects of caffeine were found in the delta and beta bandwidths, but no main effects of caffeine were observed in the theta or alpha bandwidths. Overall, the effects of caffeine on EEG activity were relatively few, weak and inconsistent, and no evidence was found of net restorative effects of caffeine for any outcome variables. Conclusions: The findings do not support the use of caffeine as a means for enhancing human function or as an antidote to the negative effects of sleep loss. Copyright © 2008 John Wiley & Sons, Ltd. [source] Integrated river basin management in England and Wales: a policy perspectiveAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 4 2002G. Mance Abstract 1.There is now an irresistible momentum for a truly integrated and strategic approach to river basin management. As a consequence, the framework within which individual organizations can carry out their roles and responsibilities in a co-ordinated and sustainable way can be determined. 2.Extreme events such as floods and droughts have severe social and economic consequences. ,Traditional' engineered responses, which take little account of fluvial processes and ecosystem functioning, often exacerbate these problems and can have severe adverse consequences on the environment. 3.Bringing together a range of scientific, technical and engineering disciplines to address catchment management has many advantages. Identifying and implementing innovative solutions that benefit local communities and the environment is the only sustainable way forward for river management. 4.Public understanding of risk assessment and management is vital to the success of an integrated approach. So too is a strategic dimension to inform the town and country planning system and major investment decisions by major utilities and public bodies responsible for water supply, pollution control and flood management. 5.There are major challenges ahead for public utilities, agencies and professional bodies in terms of attracting, retaining and blending together skilled scientific, engineering and technical specialists. These skills need to be complemented by the ability to convey sophisticated information in readily understood language. Copyright © 2002 John Wiley & Sons, Ltd. [source] | ||||||||||