High performance liquid chromatography mobile phase composition optimization for the quantitative determination of a carboxylic acid compound in human plasma by negative ion electrospray high performance liquid chromatography tandem mass spectrometry

A systematic investigation was undertaken to study the effects of varying concentrations of additives in the acetonitrile/water high performance liquid chromatography mobile phase, especially formic acid and ammonium formate, on the negative ion electrospray response of a carboxylic acid compound. The study showed that the response progressively decreased with increase in the formic acid concentration. While such a decrease in the response could be qualitatively explained by the decrease in the concentration of the ionized form of the carboxylic acid compound due to the lower pH of the mobile phase, the change in response was not as large as expected from the change of the concentration of the ionized form. The response also progressively decreased with increase in the ammonium formate concentration but the decrease cannot be explained by the change in the pH of the mobile phase. Although the best negative ion electrospray response was obtained with a water/acetonitrile mobile phase that contained no additives at all, the retention time of the analyte was not found to be adequately reproducible on repeated injections. Thus, this mobile phase was deemed unacceptable for practical, routine use. Comparing formic acid against ammonium formate, the former was preferable since it caused a smaller attenuation of the negative ion response. Equally important was the fact that addition of formic acid had the desirable effect of maintaining a reasonably high capacity factor (k') for the analyte even at a relatively high acetonitrile concentration. A concentration of 1 mM formic acid in the mobile phase was large enough to achieve the reproducible elongated retention time for the analyte, with a loss in the analyte response of about 60% only. It should be noted that the sensitivity achieved with the 1 mM formic acid mobile phase, in which the carboxylic acid is expected to be about 10% in the ionized form, is about 9 times better than the sensitivity achieved in the 1 mM ammonium formate mobile phase, in which the carboxylic acid is expected to be about 99% in the ionized form.     

Task Switching After Cerebellar Damage.

The authors of this study investigated task switching following cerebellar damage. The study group consisted of 7 children and adolescents (M age = 13.8 years) who underwent surgical removal of a benign posterior fossa tumor. They were tested at a sufficient interval after surgery (M lag = 6.13 years) for restoration of normal cognitive skills and intelligence. Although all showed normal learning of the task compared with control participants, when rapid behavioral changes were required (short preparation time), they exhibited behavioral rigidity manifested by enhanced switching cost. These results are in line with another study on serial reaction time with the same patients (A. Berger et al., in press). They have important implications for our understanding of the cognitive sequelae of early cerebellar damage as well as the involvement of the cerebellum in task switching. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cost Effectiveness: A Systems Approach to Analysis of Urban Services

In the process of diffusion from the federal government into local governments, both PPBS and systems analysis face technical and staff support problems. Quantifying and relating urban service objectives with the costs and benefits of alternate solutions is extremely difficult for public agencies lacking a price mechanism. One promising approach is cost-effectiveness, which relates output to achievement of objectives, without necessarily describing output in dollars. Typically, government service measures of effectiveness have been replaced by performance measures or standards. Problems of these kinds of measures are discussed and suggestions are made for new types of measures.     

CANADIAN HYDROCARBON RESOURCE DEVELOPMENT UP TO THE YEAR 2000

Canada is blessed with numerous large and small sedimentary basins, both onshore and offshore, many of which have hardly been probed for their hydrocarbon potential. Only the most promising aspects of this potential can be highlighted in a brief review such as this, and hence the objectives of the report are (i); to present a regional assessment of the onshore and offshore basins in Canada and to document reservoir units for both conventional and non-conventional hydrocarbon occurrences within the basin fills which may yield significant discoveries in the future (Map 1), and (ii) to emphasize Canada's political-investment environment, and the roles of Petro-Canada, Native Land claims, etc., since most, if not all, of the exploratory targets mentioned require large financial commitments and stable domestic and global conditions.
Previous publications provided essential information to substantiate and/or alter views and projections expressed. Only summary papers are referred to in this review, and we apologize to authors whose views we have used but not acknowledged.     

Law as a variable in urban and regional analysis

Conclusion This paper has argued that the law itself constitutes an important variable that needs to be taken into account in analysis of urban and regional phenomena. We have begun to do impact analyses of public and private actions as required by law. We have not gone very far in analyzing the impact of existing or projected laws themselves. Formidable technical and data problems will be encountered. Yet, the growing legislative and judicial constraints and imperatives toward action in the market suggest that if we are to build models that address reality, we will have little choice but to include them specifically.The support of the National Science Foundation, Division of Law and Social Science, is gratefully acknowledged. My thanks to David Jones and Lyna Rossi for examples.     

The Concept of Planned Development: A Presentation and Commentaries on the Contribution of Nathaniel Lichfield

This article and the commentaries which accompany it centres on a reflection by consultant-academic Nathaniel Lichfield on his work on planned development and the evaluation of the impacts of such development, over a career spanning the past 60 years. His work, in the UK and across the world, had a formative influence on generations of planners brought up on his texts. In this presentation, David Adams sets the context of his contribution. The heart of the article is a reflective synthesis by Lichfield on his own work from his first major contribution in 1956, to its evolution in the 1960s into the technique of the Planning Balance Sheet, and later, Community Impact Evaluation. His starting point is that there can be urban and regional planning which does not lead to physical development on the ground and there can be such development on the ground that has not been influenced by government led urban and regional planning. Neither of these is planned development. This takes place when the two are fused together in practice: the development and the government led planning. It is this simple concept, with particular emphasis on its economics, which was treated at length in the Economics of Planned Development (1956). In order to fully describe the concept, the book's contents are summarized in the first half of this article following an introduction of the background. Following the publication of the book, Lichfield's professional and academic work took him in many directions, much of which fell loosely under the ambit of the economics of planned development. His contributions were not written up as sequels to the book but rather in related books, papers and articles under an array of topics. He terms these 'the children of EPD'. They are described in the second half of the article, grouped in relation, as appropriate, to each of the main themes of the 1956 book and extensions of it. Lichfield's article is followed by three commentaries. The first, by Mike Teitz, positions his work and its later development in the changing context of the times. The second, by Barrie Needham, provides some critical thoughts on how well the concept of 'planned development' travels transnationally into different institutional contexts. The third, from consultant-planner Alan Wenban-Smith, himself working on policy evaluation in the UK, explores the practical and methodological robustness of Lichfield's concepts. Overall, the piece provides an input to reflections on the relation between state and market in the development process and on the evaluative stance the state should take to its interventions.