Careful Study (careful + study)

Distribution by Scientific Domains


Selected Abstracts


Aplasia Cutis Congenita in a Defined Population from Northwest Spain

PEDIATRIC DERMATOLOGY, Issue 6 2006
Soledad Martinez-Regueira M.D.
It may occur as an isolated defect or associated with other anomalies. This study sought to determine the frequency of this condition over a 10-year-period at the single hospital for a well-defined population. A literature review of potential mechanisms implicated in the development of this condition was also conducted. A retrospective review of all case records of patients diagnosed with aplasia cutis congenita between January 1994 and December 2003 at Hospital Xeral-Calde, in the Lugo region of northwest Spain was undertaken. During the period of study four patients were diagnosed with this condition. Three of them were of the gypsy race. These three had aplasia cutis congenita associated with epidermolysis bullosa and deformed nails. The incidence of aplasia cutis congenita in our region was 2.8 cases per 10,000 newborns. It was found that the incidence of this disorder in northwest Spain was similar to that described in the literature. Careful study due to the frequent association of aplasia cutis congenita with other congenital anomalies and a complete obstetric and family history of all affected individuals are required to identify possible specific teratogens, intrauterine infections, chromosomal abnormalities, or history of this condition among relatives. [source]


Determination of biogenic amines in HeLa cell lysate by 6-oxy-(N -succinimidyl acetate)-9-(2',methoxycarbonyl) fluorescein and micellar electrokinetic capillary chromatography with laser-induced fluorescence detection

ELECTROPHORESIS, Issue 4 2006
Liwei Cao
Abstract An MEKC-LIF method using 6-oxy-(N -succinimidyl acetate)-9-(2'-methoxy-carbonyl) fluorescein (SAMF) newly synthesized in our lab as a labeling reagent for the separation and determination of eight typical biogenic amines was proposed. After careful study of the derivatization condition such as pH value, reagent concentration, temperature, and reaction time, derivatization reaction was accomplished as quickly as 10,min with stable yield. Optimal separation of SAMF-labeled amines was achieved with a running buffer (pH,9.3) containing 30,mM boric acid, 25,mM SDS, and 20%,v/v ACN. The proposed method allowed biogenic amines to be determined with LODs as low as 0.25,2.5,nmol/L and RSD values from 0.4 to 4.5%. The present method has been successfully used to monitor biogenic amines in HeLa cells and fish samples. This study exploits the potential of MEKC-LIF with SAMF labeling as a tool for monitoring biogenic amines involved in complex physiological and behavioral processes in various matrices. [source]


Polyacrylamide gel electrophoresis followed by sodium dodecyl sulfate gradient polyacrylamide gel electrophoresis for the study of the dimer to monomer transition of human transthyretin

ELECTROPHORESIS, Issue 14 2003
Klaus Altland
Abstract Familial amyloidotic polyneuropathy (FAP) is caused by mutations which destabilize transthyretin (TTR) and facilitate the aggregation into extracellular amyloid fibrils preferentially in peripheral nerve and heart tissues. Therapeutic and preventive trials for FAP at the plasma TTR level require a careful study of the destabilization of TTR under variable conditions. We have developed a simple double one-dimensional (D1-D) electrophoretic procedure with polyacrylamide gel electrophoresis (PAGE) followed by sodium dodecylsulfate (SDS) gradient PAGE to study the dimer to monomer transition. TTR is first isolated by PAGE from other plasma proteins. The gel strip containing the TTR fraction is incubated in 2% SDS under varying conditions of temperature, buffer composition, pH, and additives like urea and/or a sulfhydryl-reactive agent, followed by SDS-gradient PAGE for the separation of TTR dimers and monomers. We demonstrate that an unidirectional dimer to monomer transition of normal TTR is achieved at 70,80°C in neutral to mild alkaline buffers or at 37°C and slightly acidic pH (6,7). Addition of urea favors the transition into monomers. Amyloidogenic mutations like amyloidogenic TTR (ATTR)-V30M or ATTR-I107V favor the transition into monomers in buffer systems close to the physiological pH of human plasma. We conclude that this finding has to be considered by any hypothesis on ATTR-derived amyloidogenesis. [source]


Archetype Cationic Iridium Complexes and Their Use in Solid-State Light-Emitting Electrochemical Cells

ADVANCED FUNCTIONAL MATERIALS, Issue 21 2009
Rubén D. Costa
Abstract The archetype ionic transition-metal complexes (iTMCs) [Ir(ppy)2(bpy)][PF6] and [Ir(ppy)2(phen)][PF6], where Hppy,=,2-phenylpyridine, bpy,=,2,2,-bipyridine, and phen,=,1,10-phenanthroline, are used as the primary active components in light-emitting electrochemical cells (LECs). Solution and solid-state photophysical properties are reported for both complexes and are interpreted with the help of density functional theory calculations. LEC devices based on these archetype complexes exhibit long turn-on times (70 and 160,h, respectively) and low external quantum efficiencies (,2%) when the complex is used as a pure film. The long turn-on times are attributed to the low mobility of the counterions. The performance of the devices dramatically improves when small amounts of ionic liquids (ILs) are added to the Ir-iTMC: the turn-on time improves drastically (from hours to minutes) and the device current and power efficiency increase by almost one order of magnitude. However, the improvement of the turn-on time is unfortunately accompanied by a decrease in the stability of the device from 700 h to a few hours. After a careful study of the Ir-iTMC:IL molar ratios, an optimum between turn-on time and stability is found at a ratio of 4:1. The performance of the optimized devices using these rather simple complexes is among the best reported to date. This holds great promise for devices that use specially-designed iTMCs and demonstrates the prospect for LECs as low-cost light sources. [source]


The Breakthrough of Another West European Populist Radical Right Party?

GOVERNMENT AND OPPOSITION, Issue 4 2010
The Case of the True Finns
The True Finn Party (PS), which gained virtually 10 per cent of the national vote at the 2009 European Parliament election, lacks a place in the comparative party literature and also defies ready classification. It has been perceived by its supporters as the most left-wing of the non-socialist parties; by Finnish media commentators as a case of right-wing populism; and by researchers as a distinctive centred-based populist party when viewed in a wider European perspective. Based on a careful study of its programmatic output since its inception in 1995, this article seeks to characterize the PS by reference to its core ideological features. It argues that it is in fact a populist radical right party , with national identity or Finnishness as its pivotal concept , albeit without the xenophobic extremism of such continental counterparts as the Danish People's Party or Austrian Freedom Party. [source]


The Underside of Conflict Management , in Africa and Elsewhere

IDS BULLETIN, Issue 1 2001
Laura Nader
Summaries This article traces the evolution of thought on dispute resolution in recent decades and takes a critical look at its latest incarnation, the alternative dispute resolution (ADR) revolution. It argues that ADR is premised on the harmony model of law that denies the unequal power of disputing parties and ignores issues of social justice. It calls for a real dialogue by serious scholars willing to examine the now plentiful evidence of the performance of ADR devices. The article also shows that dispute resolution is not autonomous from other social and economic components of social systems, and that as a consequence it is not possible to divorce law and power. Any ADR scheme, therefore, needs careful study of the social conditions in which it may operate. [source]


The Participant's Dilemma: Bringing Conflict and Representation Back In

INTERNATIONAL JOURNAL OF URBAN AND REGIONAL RESEARCH, Issue 3 2010
DEBBIE BECHER
Abstract Innovations in democratic participation involving small-scale, long-term focused governing bodies have increased citizen influence in poor American urban neighborhoods. Scholars have described these emerging forms of participation as essentially cooperative in spirit and directly democratic in nature. I argue that the new participatory regimes continue to involve social processes of representation and conflict inherent to more traditional forms of engagement. Participants move dynamically between cooperation and conflict and between participating as individuals and representing constituencies. This article presents a careful study of how a single decision developed and was implemented in such a participatory experiment, the American Street Empowerment Zone in Philadelphia, Pennsylvania, USA, between 1994 and 2008. Archival and interview data support the general perspective shared by articles in this symposium , that participation involves dynamic movement between conflict and cooperation. This article suggests that the durability of the participatory regime depends not on the level of conflict but on how participants move between displaying identification with either government or their community constituents. This article uses the concept of intermediation to describe this kind of dynamism and to reflect the flexibility a participatory structure must nurture to endure. Résumé Les innovations en matière de participation démocratique qui impliquent des organes de gouvernement ,uvrant à petite échelle et à long terme ont accru l'influence des habitants dans les quartiers urbains pauvres américains. D'après certains auteurs, ces formes nouvelles de participation sont, dans l'esprit, essentiellement coopératives et, par nature, directement démocratique. Il est exposé ici que les nouveaux régimes participatifs font encore intervenir des processus sociaux de représentation et de conflit propres à des formes d'engagement plus traditionnelles. Les participants oscillent de manière dynamique entre coopération et conflit, et entre participation en tant qu'individus et représentation collective. Cet article présente une étude minutieuse de la manière dont une décision a étéélaborée et mise en ,uvre dans le cadre d'une expérience participative de ce type, ,American Street Empowerment Zone'à Philadelphie (Pennsylvanie), de 1994 à 1998. Des données issues d'archives et d'entretiens corroborent la perspective générale commune aux articles de ce symposium: la participation implique un mouvement dynamique entre conflit et coopération. L'article suggère que la pérennité du régime participatif dépend, non pas du niveau de conflit, mais de la façon dont les participants alternent dans leur manifestation d'une identification soit au gouvernement soit aux membres de leur communauté. Le concept d'intermédiation est utilisé pour décrire cette forme de dynamique et pour traduire la souplesse que doit garder une structure participative pour perdurer. [source]


A limiting absorption principle for scattering problems with unbounded obstacles

MATHEMATICAL METHODS IN THE APPLIED SCIENCES, Issue 14 2001
Anne-Sophie Bonnet-Bendhia
Abstract A generalized mode matching method that applies to a wide class of scattering problems is developed in the time harmonic two-dimensional Helmholtz case. This method leads by variational means to an integro-differential formulation whose unknown is the trace of the field on an unbounded one-dimensional interface. The well-posedness is proved after a careful study of the rather original functional framework. Owing to a fundamental density result,based upon some properties of a singular integral operator similar to the Hilbert transform,the limiting absorption principle related to this original formulation is established. Finally, two other situations are emphasized. Copyright © 2001 John Wiley & Sons, Ltd. [source]


Philosophical Issues Arising from Experimental Economics

PHILOSOPHY COMPASS (ELECTRONIC), Issue 3 2007
Zachary Ernst
Human beings are highly irrational, at least if we hold to an economic standard of ,rationality'. Experimental economics studies the irrational behavior of human beings, with the aim of understanding exactly how our behavior deviates from the Homo economicus, as ,rational man' has been called. Insofar as philosophical theories depend upon rationality assumptions, experimental economics is the source of both problems and (at least potential) solutions to several philosophical issues. This article offers a programmatic and highly biased survey of some of these issues, with the hope of convincing the reader that experimental economics is well-deserving of careful study by philosophers. [source]


Assessing the outdoor operating temperature of photovoltaic modules

PROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 4 2008
David Faiman
Abstract By a careful study of data collected from seven varieties of photovoltaic (PV) module it is demonstrated that a simple modified form of the Hottel,Whillier,Bliss (HWB) equation, familiar from the analysis of flat-plate solar,thermal collectors, can be employed to predict module temperatures within an accuracy comparable to the cell-to-cell temperature differences typically encountered within a module. Furthermore, for modules within the range of construction parameters employed in this study, the actual values of the two modified HWB constants do not appear to depend upon module type. The implication of these results for the accuracy of outdoor module characterization is discussed. Copyright © 2008 John Wiley & Sons, Ltd. [source]


N -Acyl amino acids and N -acyl neurotransmitter conjugates: neuromodulators and probes for new drug targets

BRITISH JOURNAL OF PHARMACOLOGY, Issue 8 2010
Mark Connor
The myriad functions of lipids as signalling molecules is one of the most interesting fields in contemporary pharmacology, with a host of compounds recognized as mediators of communication within and between cells. The N -acyl conjugates of amino acids and neurotransmitters (NAANs) have recently come to prominence because of their potential roles in the nervous system, vasculature and the immune system. NAAN are compounds such as glycine, GABA or dopamine conjugated with long chain fatty acids. More than 70 endogenous NAAN have been reported although their physiological role remains uncertain, with various NAAN interacting with a low affinity at G protein coupled receptors (GPCR) and ion channels. Regardless of their potential physiological function, NAAN are of great interest to pharmacologists because of their potential as flexible tools to probe new sites on GPCRs, transporters and ion channels. NAANs are amphipathic molecules, with a wide variety of potential fatty acid and headgroup moieties, a combination which provides a rich source of potential ligands engaging novel binding sites and mechanisms for modulation of membrane proteins such as GPCRs, ion channels and transporters. The unique actions of subsets of NAAN on voltage-gated calcium channels and glycine transporters indicate that the wide variety of NAAN may provide a readily exploitable resource for defining new pharmacological targets. Investigation of the physiological roles and pharmacological potential of these simple lipid conjugates is in its infancy, and we believe that there is much to be learnt from their careful study. [source]


Total Synthesis of Ouabagenin and Ouabain

CHEMISTRY - AN ASIAN JOURNAL, Issue 5 2009
Maddi, Sridhar Reddy Dr.
Abstract All done! A full account of the total synthesis of ouabagenin and ouabain has been described. The synthesis was achieved through a polyanionic cyclization strategy. Degradation studies provide an ultimate proof for a key intermediate observed in the synthesis. A full account of the total synthesis of ouabagenin and ouabain is described. A highly stereocontrolled anionic cycloaddition for the rapid construction of the basic steroid skeleton is a pivotal conversion for the whole strategy. A careful study was needed to establish the order and the sequence of functional group manipulations. Specific conformational features of the ouabain skeleton allowed us to overcome a few stereochemical problems. Degradation studies on ouabain provided an ultimate proof for a key intermediate, which is used as a relay. Late stage butenolide formation and glycosidation yielded ouabain. [source]