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Current Interest (current + interest)
Kinds of Current Interest Selected AbstractsCity-Regions, Neoliberal Globalization and Democracy: A Research AgendaINTERNATIONAL JOURNAL OF URBAN AND REGIONAL RESEARCH, Issue 1 2007MARK PURCELL This paper argues that research on city-regions could benefit from more sustained and critical attention to the question of democracy. That is, it should examine more closely how decisions in city-regions are made, why they are made that way, and how they can be made more democratically. Much current research on politics in cities has framed the issue in terms of citizenship. That work has produced great insight. However, the attention to citizenship has prompted very little attention to democracy, even though the two concepts are deeply intertwined. Current interest in city-regions opens up the possibility that a vibrant line of research on democracy can be added to and engage with that on citizenship. [source] Prospects for the use of differentiation-modulating agents as adjuvant of photodynamic therapy for proliferative dermatosesTHE JOURNAL OF DERMATOLOGY, Issue 4 2008Oleg E. AKILOV ABSTRACT Current interest in photodynamic therapy (PDT) in dermatology stems from its recognized success in dermatological oncology, straightforward approach, easy accessibility and low cost. PDT is a photochemistry-based modality in which a light-activated photosensitizer (PS) destroys tissue through oxygen-dependent and -independent mechanisms. Although PDT has been used in dermatology for several decades, its application has still not extended significantly into the routine management of neoplastic and proliferative dermatoses because of continuing issues with the selectivity of the PS for affected tissues. This review analyzes prospects for optimization of PDT for the management of dermatoses with defects in keratinocyte proliferation/differentiation, and discusses the use of differentiating agents that redirect metabolic utilization within cells and lead to high levels of PS accumulation. [source] Appraising, researching and conceptualizing criminal thinking: a personal viewCRIMINAL BEHAVIOUR AND MENTAL HEALTH, Issue 2 2006GLENN D. WALTERS Background,It is argued that current interest in the concept of criminal thinking has its roots in traditional theories of criminology and criminal justice such as Sutherland's differential association model, neutralization theory, and Yochelson and Samenow's criminal personality. Aim,The purpose of this paper is to briefly review and summarize theory, research, and practice on criminal thinking as it relates to the author's work in this area. Conclusions,Three self-report inventories , the Criminal Sentiments Scale (CSS), the Psychological Inventory of Criminal Thinking Styles (PICTS), and the Measures of Criminal Attitudes and Associates (MCAA); three principal areas of research , criminal thinking as a predictor of criminal behaviour, offence as a moderator of criminal thinking, and changes in criminal thinking leading to changes in criminal behaviour; and a general theory of criminal thinking are briefly reviewed in this paper. Copyright © 2006 John Wiley & Sons, Ltd. [source] The Corset Platysma Repair: A Technique RevisitedDERMATOLOGIC SURGERY, Issue 3 2002Carolyn I. Jacob MD background. Platysma banding along with excess submental adipose tissue and sagging skin can lead to an aged appearance. Several methods for improving neck and submental contours exist, including neck liposuction, bilateral platysma plication, midline platysma plication with transection of distal fibers, necklift with skin excision, and botulinum toxin injection for platysma relaxation. With the current interest in minimally invasive procedures, surgeons and patients are searching for techniques that produce maximal improvement with minimal intervention. objective. To present a modified technique for maximizing neck contouring, discuss possible complications of the procedure, and describe appropriate candidates for the corset platysmaplasty. methods. We performed a retrospective analysis of 10 consecutive patients who underwent neck liposuction with concomitant corset platysmaplasty at our institution. results. All 10 patients achieved good to excellent submental and jawline contouring, determined by both physician and patient assessment, with no visible platysma banding at 6 months follow-up. No major complications were noted. conclusion. Use of corset platysmaplasty is a safe and effective method for neck rejuvenation. This variation of platysmaplasty can be used in conjunction with neck liposuction to maximize jawline and neck contour enhancement. [source] Behaviourally structured populations persist longer under harsh environmental conditionsECOLOGY LETTERS, Issue 5 2003Sergei V. Petrovskii Abstract The factors and mechanisms that enhance population persistence in a fragmented habitat and/or under harsh environmental conditions are of significant current interest. We consider the dynamics of a population in an isolated habitat surrounded by an unfavourable environment subject to different behavioural responses between the individuals. We assume that there are two responses available: one of them is aggression in its extreme form, the other is its contrary when an individual takes flight in order to avoid any contact with its conspecific. We show that a behaviourally structured population consisting of individuals with fixed behavioural responses is intrinsically less prone to extinction under harsh environmental condition than a population where the individuals can ,choose' between the two given behaviours. We also show that, contrary to an intuitively expected negative impact of aggression on population persistence, the optimal conditions for population persistence are reached when a considerable proportion of the individuals exhibit aggressive behaviour. [source] Quality of equine veterinary care: Where can it go wrong?EQUINE VETERINARY EDUCATION, Issue 3 2008A conceptual framework for the quality of equine healthcare, based on court cases against equine practitioners in The Netherlands Summary Quality control and client satisfaction are topics of considerable current interest in both human and veterinary healthcare. Crucial to this discussion is a proper definition of ,quality of care'. This study applied, to (equine) veterinary care, a conceptual framework designed for assessing the quality of human healthcare and featuring structural deficiency, procedural inadequacy and disappointing outcome as key elements. This was done using court cases against equine practitioners as a yardstick for client dissatisfaction. Applying a system for evaluating the quality of healthcare may be a good way of monitoring and improving (equine) veterinary services, particularly once reliable indices for client satisfaction have been validated. [source] Facts, fantasies and fun in epithelial physiologyEXPERIMENTAL PHYSIOLOGY, Issue 3 2008C. A. R. Boyd The hallmark of epithelial cells is their functional polarization. It is those membrane proteins that are distributed differentially, either to the apical or to the basal surface, that determine epithelial physiology. Such proteins will include ,pumps', ,channels' and ,carriers', and it is the functional interplay between the actions of these molecules that allows the specific properties of the epithelium to emerge. Epithelial properties will additionally depend on: (a) the extent to which there may be a route between adjacent cells (the ,paracellular' route); and (b) the folding of the epithelium (as, for example, in the loop of Henle). As for other transporters, there is polarized distribution of amino-acid carriers; the molecular basis of these is of considerable current interest with regard to function, including ,inborn errors' (amino-acidurias); some of these transporters have additional functions, such as in the regulation of cell fusion, in modulating cell adherence and in activating intracellular signalling pathways. Collaboration of physiologists with fly geneticists has generated new insights into epithelial function. One example is the finding that certain amino-acid transporters may act as ,transceptors' and play a role as sensors of the extracellular environment that then regulate intracellular pathways controlling cell growth. [source] Assembly of Gold Nanoparticles in a Rod-Like Fashion Using Proteins as Templates,ADVANCED FUNCTIONAL MATERIALS, Issue 3 2006R. Bhattacharya Abstract An area of considerable current interest is the development of a practical approach for assembling inorganic nanoparticles into well-defined arrays because such a technique would offer immense opportunities leading to applications in microimaging, optoelectronics, therapeutics, etc. This paper illustrates a new, simple one-step process in which proteins act as templates to assemble gold nanoparticles in a shape-selective fashion. We show, for the first time, that antibodies to vascular endothelial growth factor 165 isoform, 2C3, and epidermal growth factor receptor can act as templates when present in solution during the synthesis of gold nanoparticles. These proteins direct the assembly of the gold nanoparticles into rod-like shapes when cooled to ,20,°C followed by thawing at room temperature. Immunoglobulin,G and bovine serum albumin can also direct the assembly process in a similar fashion; however, small molecules, such as poly(L -lysine) and lysine, cannot. The formation of a self-assembled structure in the form of a continuous rod, or the assembly of discrete nanoparticles in a rod-like fashion, can be tailored by controlling the ratio of the precursor gold salt, HAuCl4, to the antibody/protein used as the template. The nanoconjugates are characterized using UV-vis spectroscopy, transmission electron microscopy, and infrared spectroscopy. The nano-bioconjugates obtained via this process may find wide application in areas ranging from optoelectronics and biosensors to therapeutics in neoplastic disorders. [source] Henry VII in Context: Problems and PossibilitiesHISTORY, Issue 307 2007STEVEN GUNN Clearer understanding of Henry VII's reign is hindered not only by practical problems, such as deficiencies in source material, but also by its liminal position in historical study, at the end of the period conventionally studied by later medievalists and the beginning of that studied by early modernists. This makes it harder to evaluate changes in the judicial system, in local power structures, in England's position in European politics, in the rise of new social groups to political prominence and in the ideas behind royal policy. However, thoughtful combination of the approaches taken by different historical schools and reflection on wider processes of change at work in Henry's reign, such as in England's cultural and economic life, can make a virtue out of Henry's liminality. Together with the use of more unusual sources, such an approach enables investigation for Henry's reign of many themes of current interest to historians of the later Tudor period. These include courtly, parliamentary and popular politics, political culture, state formation and the interrelationships of different parts of the British Isles and Ireland. [source] Finding the Middle-Ground: The Middling Sort in the Eighteenth CenturyHISTORY COMPASS (ELECTRONIC), Issue 2 2006Perry Gauci Since the 1980s the debate on the impact of the middle classes in eighteenth-century Britain has helped to transform current interest and thinking on the period. No consensus has been reached on the degree of social and political change at this time, but our understanding of middling experience has been enhanced by a range of new themes and approaches, the resonance of which continues to enliven the field. [source] Combining fMRI and SNP data to investigate connections between brain function and genetics using parallel ICA,HUMAN BRAIN MAPPING, Issue 1 2009Jingyu Liu Abstract There is current interest in understanding genetic influences on both healthy and disordered brain function. We assessed brain function with functional magnetic resonance imaging (fMRI) data collected during an auditory oddball task,detecting an infrequent sound within a series of frequent sounds. Then, task-related imaging findings were utilized as potential intermediate phenotypes (endophenotypes) to investigate genomic factors derived from a single nucleotide polymorphism (SNP) array. Our target is the linkage of these genomic factors to normal/abnormal brain functionality. We explored parallel independent component analysis (paraICA) as a new method for analyzing multimodal data. The method was aimed to identify simultaneously independent components of each modality and the relationships between them. When 43 healthy controls and 20 schizophrenia patients, all Caucasian, were studied, we found a correlation of 0.38 between one fMRI component and one SNP component. This fMRI component consisted mainly of parietal lobe activations. The relevant SNP component was contributed to significantly by 10 SNPs located in genes, including those coding for the nicotinic ,-7cholinergic receptor, aromatic amino acid decarboxylase, disrupted in schizophrenia 1, among others. Both fMRI and SNP components showed significant differences in loading parameters between the schizophrenia and control groups (P = 0.0006 for the fMRI component; P = 0.001 for the SNP component). In summary, we constructed a framework to identify interactions between brain functional and genetic information; our findings provide a proof-of-concept that genomic SNP factors can be investigated by using endophenotypic imaging findings in a multivariate format. Hum Brain Mapp, 2009. © 2007 Wiley-Liss, Inc. [source] Psychosocial risk exposures and musculoskeletal disorders across working-age males and femalesHUMAN FACTORS AND ERGONOMICS IN MANUFACTURING & SERVICE INDUSTRIES, Issue 4 2010John Collins Abstract In 2008, The European Agency for Safety and Health at Work (EU-OSHA) reported that musculoskeletal disorders (MSDs) were the most common work-related health problem in Europe. Females are considered more susceptible to MSDs than are males, and older workers are more vulnerable than are younger workers. Factors specific to the job, work organization, and individual have been implicated as potential risk factors, with current interest focusing on psychosocial risk factors and the pathology of disorders. Although there is some disagreement in the literature, there is growing support that, after controlling for exposure, females have a predisposition to MSDs. More is known of the role of psychosocial risks in MSD etiology, but it is unclear if there are differences in exposures across gender and age and if this has a resultant effect on injury rates. The purpose of this study was to investigate the prevalence of MSDs and trends with psychosocial risks, across age and gender. The study group consisted of 200 female and 132 male employees from varied occupations within Ireland, ranging from age 18,66 years. The most prevalent symptoms of MSDs were for the lower back, shoulder, and neck regions. Age and gender differences in prevalence were evident for these regions. There was a general trend for increasing prevalence with age. For the psychosocial risks, significant differences in job content exposures were observed across age groups for males (p < 0.05) and females (p < 0.0005). There were also differences in scores across the age groups for mental health (p < 0.0005) and insecurity at work (p < 0.0005) for the females. The conclusions are that there were not sufficiently strong differences in exposures to relevant psychosocial risks both between genders and across age for a resultant effect on MSDs. © 2010 Wiley Periodicals, Inc. [source] PD-1 signalling in CD4+ T cells restrains their clonal expansion to an immunogenic stimulus, but is not critically required for peptide-induced toleranceIMMUNOLOGY, Issue 1 2010Joanne E. Konkel Summary The ultimate outcome of T-cell recognition of peptide,major histocompatibility complex (MHC) complexes is determined by the molecular context in which antigen presentation is provided. The paradigm is that, after exposure to peptides presented by steady-state dendritic cells (DCs), inhibitory signals dominate, leading to the deletion and/or functional inactivation of antigen-reactive T cells. This has been utilized in a variety of models providing peptide antigen in soluble form in the absence of adjuvant. A co-inhibitory molecule of considerable current interest is PD-1. Here we show that there is the opportunity for the PD-1/PD-L1 interaction to function in inhibiting the T-cell response during tolerance induction. Using traceable CD4+ T-cell receptor (TCR) transgenic cells, together with a blocking antibody to disrupt PD-1 signalling, we explored the roles of PD-1 in the induction of tolerance versus a productive immune response. Intact PD-1 signalling played a role in limiting the extent of CD4+ T-cell accumulation in response to an immunogenic stimulus. However, PD-1 signalling was not required for either the induction, or the maintenance, of peptide-induced tolerance; a conclusion underlined by successful tolerance induction in TCR transgenic cells genetically deficient for PD-1. These observations contrast with the reported requirement for PD-1 signals in CD8+ T-cell tolerance. [source] A case of uterine tumour resembling ovarian sex cord tumour responding to second-line, single agent anastrazoleINTERNAL MEDICINE JOURNAL, Issue 9 2009P. Blinman Abstract Uterine tumour resembling ovarian sex cord tumour (UTROSCT) are a histological variant of endometrial stromal sarcomas (ESS). There is no established medical management of metastatic UTROSCT or ESS, although there is evidence supporting the use of hormonal therapy. Given the success of aromatase inhibitors in breast cancer, their potential role in ESS and UTROSCT is of current interest. We report the first case of response to second-line, single agent anastrazole in a patient with metastatic UTROSCT. [source] Biodegradable polymers: An updateISRAEL JOURNAL OF CHEMISTRY, Issue 4 2005Ariella Shikanov The use of polymeric materials for the administration of pharmaceuticals, and as biomedical devices has increased dramatically. This review focuses on synthetic biodegradable polymers of current interest for medical use, based on ester and anhydride bonds. Special attention is given to factors affecting biodegradation, including: polymer structure, morphology, molecular weight, radiation, and chemical treatment, as well as the effects of drugs and plasticizers added to the polymer mass. The toxicity and biocompatibility of the polymers and their current and future applications in medicine are also briefly reviewed. [source] Financial volatility: an introductionJOURNAL OF APPLIED ECONOMETRICS, Issue 5 2002Philip Hans Franses It is now 20 years since the publication of Engle's (1982) seminal paper, which introduced ARCH to the world. The ARCH paper had an enormous influence on both theoretical and applied econometrics, and was influential in the establishment of the discipline of Financial Econometrics. In this paper we provide an introduction to the special issue on modelling and forecasting financial volatility, which commemorates the Twentieth Anniversary of the publication of ARCH. Financial econometrics has become a mature discipline over the last two decades, and one of its major research objects is the modelling and forecasting of volatility. This special issue presents ten papers, all of which focus on volatility and risk. The papers examine issues such as the new frontiers of volatility, the selection of models for observed and unobserved volatility, the potential long-memory property of volatility, and the measurement of volatility. The commonality of papers is that they do not examine the extant literature, which has been reviewed elsewhere, but rather outline a number of important issues that are not only of current interest, but are likely to remain so for many years to come. Copyright © 2002 John Wiley & Sons, Ltd. [source] Nonmalignant Complications of Paget's DiseaseJOURNAL OF BONE AND MINERAL RESEARCH, Issue S2 2006Henry G Bone Abstract Paget's disease of bone is a focal or multifocal disorder characterized by intense disorderly remodeling activity at sites of involvement, producing dramatic alterations of local bone architecture. These functional and structural alterations, interacting with the specific characteristics of the site of involvement, account for most of the complications of the disease. This presentation will focus on selected nonneoplastic complications of particular current interest. [source] Esophageal Temperature During Radiofrequency-Catheter Ablation of Left Atrium: A Three-Dimensional Computer Modeling StudyJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 4 2006FERNANDO HORNERO M.D., Ph.D. Introduction: There is current interest in finding a way to minimize thermal injury in the esophagus during radiofrequency-catheter ablation of the left atrium. Despite the fact that the esophageal temperature is now being monitored during ablation, the influence of different anatomic and technical factors on the temperature rise remains unknown. Methods and Results: We implemented a three-dimensional computational model that included atrial tissue, epicardial fat, esophagus, aorta, and lung, all linked by connective tissue. The finite-element method was used to calculate the esophageal temperature distribution during a procedure of constant-temperature ablation with an 8-mm electrode, under different tissue conditions. Results showed that the distance between electrode and esophagus was the most important anatomic factor in predicting the esophageal temperature rise, the composition of the different tissues being of lesser importance. The measurement of the esophageal temperature in different sites of the lumen offered differences up to 3.7°C, especially for a short electrode,esophagus distance (5 mm). The difference in the convective cooling by circulating blood around electrode and endocardium did not show a significant influence on the esophageal temperature rise. Conclusion: Computer results suggest that (1) the electrode,esophagus distance is the most important anatomic factor; (2) the incorrect positioning of an esophageal temperature probe could give a low reading for the maximum temperature reached in the esophagus; and (3) the different cooling effect of the circulating blood flow at different atrial sites has little impact on the esophageal temperature rise. [source] Prescription drug samples , does this marketing strategy counteract policies for quality use of medicines?JOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 4 2003K. E. M. Groves BSc MSc PhD (Cand) Summary Prescription drug samples, as used by the pharmaceutical industry to market their products, are of current interest because of their influence on prescribing, and their potential impact on consumer safety. Very little research has been conducted into the use and misuse of prescription drug samples, and the influence of samples on health policies designed to improve the rational use of medicines. This is a topical issue in the prescription drug debate, with increasing costs and increasing concerns about optimizing use of medicines. This manuscript critically evaluates the research that has been conducted to date about prescription drug samples, discusses the issues raised in the context of traditional marketing theory, and suggests possible alternatives for the future. [source] Interaction between flavonoids and the blood,brain barrier: in vitro studiesJOURNAL OF NEUROCHEMISTRY, Issue 1 2003Kuresh A. Youdim Abstract There is considerable current interest in the neuroprotective effects of flavonoids. This study focuses on the potential for dietary flavonoids, and their known physiologically relevant metabolites, to enter the brain endothelium and cross the blood,brain barrier (BBB) using well-established in vitro models (brain endothelial cell lines and ECV304 monolayers co-cultured with C6 glioma cells). We report that the citrus flavonoids, hesperetin, naringenin and their relevant in vivo metabolites, as well as the dietary anthocyanins and in vivo forms, cyanidin-3-rutinoside and pelargonidin-3-glucoside, are taken up by two brain endothelial cell lines from mouse (b.END5) and rat (RBE4). In both cell types, uptake of hesperetin and naringenin was greatest, increasing significantly with time and as a function of concentration. In support of these observations we report for the first time high apparent permeability (Papp) of the citrus flavonoids, hesperetin and naringenin, across the in vitro BBB model (apical to basolateral) relative to their more polar glucuronidated conjugates, as well as those of epicatechin and its in vivo metabolites, the dietary anthocyanins and to specific phenolic acids derived from colonic biotransformation of flavonoids. The results demonstrate that flavonoids and some metabolites are able to traverse the BBB, and that the potential for permeation is consistent with compound lipophilicity. [source] Hybrid metal,polymer composites from functional block copolymersJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 19 2005Robert B. Grubbs Abstract The combination of metals and polymers in hybrid materials is a research area of great current interest. A number of methods for controlling the positioning of metallic species within polymer matrices on the nanometer scale have been developed. This highlight focuses on the use of functional block copolymers for the localization of metal species, especially nanoparticles, on the nanometer scale through block copolymer phase segregation. Research from the author's group on the use of alkyne-functional block copolymers for the preparation of cobalt-containing materials is discussed in this context. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4323,4336, 2005 [source] Marfey's reagent: Past, present, and future uses of 1-fluoro-2,4-dinitrophenyl-5-L-alanine amideJOURNAL OF SEPARATION SCIENCE, JSS, Issue 1-2 2003Clayton B'Hymer Abstract This article describes some of the uses of Marfey's reagent, 1-fluoro-2,4-dinitrophenyl-5-L-alanine amide (FDAA), a pre-column derivatizing reagent for the separation of enantiomeric isomers of amino acids and amine compounds. An introduction to the basic implementation of this reagent and its historical development are presented. Actual uses in amino acid, short peptide, and pharmaceutical compounds are included, as well as the advantages and disadvantages over other pre-column derivatization techniques and direct chromatographic separations. Applications of current interest, including its use as an orthogonal analysis and in enantiomeric purity analysis of selenoamino acids using element specific detection, are also discussed. [source] Place, Landscape, and Environment: Anthropological Archaeology in 2009AMERICAN ANTHROPOLOGIST, Issue 2 2010Christopher Rodning ABSTRACT, Topics of current interest to anthropological archaeologists include the relationships between people and place, interactions between people and past environments, and responses by past societies to changes in the natural environment. In this article, I focus on recent considerations of past landscapes and the built environment. This research concentrates on such topics as architecture, the utilization of different environmental zones, and transitions from foraging to farming, one of the long-standing topics of interest to anthropological archaeology. Recent archaeological research also emphasizes climate change and warfare, topics that have relevance to current events and conditions in the modern world. [source] Functional complementarity in the arbuscular mycorrhizal symbiosisNEW PHYTOLOGIST, Issue 2 2000ROGER T. KOIDE The causes and consequences of biodiversity are central themes in ecology. Perhaps one reason for much of the current interest in biodiversity is the belief that the loss of species (by extinction) or their gain (by invasion) will significantly influence ecosystem function. Arbuscular mycorrhizal (AM) fungi are components of most terrestrial ecosystems and, while many research programs have shown that variability among species or isolates of AM fungi does occur (Giovannetti & Gianinazzi-Pearson, 1994), the basis for this variability and its consequences to the function of communities and ecosystems remains largely unexplored. Smith et al. (pp. 357,366 in this issue) now show clearly that ecologically significant functional diversity exists among AM fungal species in the regions of the soil from which they absorb phosphate, and their results suggest that such diversity may have significant ecological consequences. [source] Computational chemistry study of the environmentally important acid-catalyzed hydrolysis of atrazine and related 2-chloro- s -triazinesPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 8 2002Phillip Sawunyama Abstract Many chlorine-containing pesticides, for example 2-chloro- s -triazines, are of great concern both environmentally and toxicologically. As a result, ascertaining or predicting the fate and transport of these compounds in soils and water is of current interest. Transformation pathways for 2-chloro- s -triazines in the environment include dealkylation, dechlorination (hydrolysis), and ring cleavage. This study explored the feasibility of using computational chemistry, specifically the hybrid density functional theory method, B3LYP, to predict hydrolysis trends of atrazine (2-chloro- N4 -ethyl- N6 -isopropyl-1,3,5-triazine-2,4-diamine) and related 2-chloro- s -triazines to the corresponding 2-hydroxy- s -triazines. Gas-phase energetics are described on the basis of calculations performed at the B3LYP/6-311++G(d,p)//B3LYP/6-31G* level of theory. Calculated free energies of hydrolysis (,hG298) are nearly the same for simazine (2-chloro- N4,N6 -diethyl-1,3,5-triazine-2,4-diamine), atrazine, and propazine (2-chloro- N4,N6 -di-isopropyl-1,3,5-triazine-2,4-diamine), suggesting that hydrolysis is not significantly affected by the side-chain amine-nitrogen alkyl substituents. High-energy barriers also suggest that the reactions are not likely to be observed in the gas phase. Aqueous solvation effects were examined by means of self-consistent reaction field methods (SCRF). Molecular structures were optimized at the B3LYP/6-31G* level using the Onsager model, and solvation energies were calculated at the B3LYP/6-311++G(d,p) level using the isodensity surface polarizable continuum model (IPCM). Although the extent of solvent stabilization was greater for cationic species than neutral ones, the full extent of solvation is underestimated, especially for the transition state structures. As a consequence, the calculated hydrolysis barrier for protonated atrazine is exaggerated compared with the experimentally determined one. Overall, the hydrolysis reactions follow a concerted nucleophilic aromatic substitution (SNAr) pathway. Published in 2002 for SCI by John Wiley & Sons, Ltd [source] Simulation and validation of resin flow during manufacturing of composite panels containing embedded impermeable inserts with the VARTM processPOLYMER COMPOSITES, Issue 4 2007Jeffrey M. Lawrence Modern composite materials are becoming more and more advanced as engineers are better able to take advantage of their properties. In addition to their lighter weight and net-shape manufacturing, current interest is to make these materials multifunctional. This may require one to insert various objects into the composite to achieve a variety of different goals. It is important to understand how these embedded objects will affect both the manufacturing and the structural integrity of the component. In this work, the effects of impermeable embedded inserts on the infusion stage of vacuum-assisted resin transfer molding (VARTM) will be explored. In VARTM, one places a distribution media on top of the preform to aid the filling as the resin will first fill the face of the preform in contact with the distribution media and will then infuse the preform in the thickness direction. However, if one has an embedded impermeable insert in the thickness direction, it will obstruct the flow in the region below the embedded object. Several case studies are conducted to understand the effect of the geometry and placement of the embedded insert and the distribution media lay out and properties on the impregnation of the resin into the fiber preform. Finally, an approach is outlined to modify the layout of the distribution media in order to ensure a complete saturation of the preform under all but the most extreme conditions. The approach is validated with experiments. POLYM. COMPOS., 28:442,450, 2007. © 2007 Society of Plastics Engineers [source] Emulsion copolymerization of styrene and sodium styrene sulfonate: kinetics, monomer reactivity ratios and copolymer propertiesPOLYMER INTERNATIONAL, Issue 1 2009Dhamodaran Arunbabu Abstract BACKGROUND: The synthesis of poly[styrene- co -(sodium styrene sulfonate)], poly(S- co -NaSS), with a high loading of sulfonate groups is of current interest owing to its potential use in numerous areas. A series of these copolymers with various sulfonate loads were synthesized using the emulsion polymerization technique with a study of the copolymerization kinetics, monomer reactivity ratio and copolymer properties. RESULTS: The copolymerization kinetics are significantly enhanced with an increase of NaSS feed in the polymerization. Monomer reactivity ratios were determined from NMR data by employing the Fineman,Ross and Kelen,Tüdös methods. Styrene (r1) and NaSS (r2) reactivity ratios are 0.5 and 10, respectively. The colloidal particle size of the copolymers depends upon the NaSS composition. The thermal stability of the copolymers is greatly enhanced with higher NaSS content in the copolymer backbone. Higher glass transition temperatures are observed for the copolymers with higher NaSS content. CONCLUSION: The reactivity ratio values suggest that styrene prefers to form copolymers whereas NaSS produces homopolymers. It is also found that styrene copolymerization with NaSS is only twice as fast as homopolymerization. In contrast, NaSS homopolymerization is ten times faster than NaSS copolymerization with styrene. The NaSS content in the copolymer backbone affects the thermal stability and the glass transition of the copolymers. Copyright © 2008 Society of Chemical Industry [source] Molecular and cellular themes in inflammation and immunology,THE JOURNAL OF PATHOLOGY, Issue 2 2008CS Herrington Abstract This issue of the Journal of Pathology contains a series of cutting-edge review articles that deal with the broad issue of inflammatory and immunological disease mechanisms. Of necessity, these reviews deal with selected topics but the mixture of articles on specific signalling pathways and mediators with articles addressing individual organ systems provides a broad overview of the field. These contributions provide insight into current areas of debate in inflammation and immunology. In particular, they highlight current interest in the interface between innate and adaptive immunity and present intriguing prospects for future therapeutic developments in a variety of disease areas. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [source] Mitosis in diatoms: rediscovering an old model for cell divisionBIOESSAYS, Issue 8 2009Alessandra De Martino Abstract Diatoms are important protists that generate one fifth of the oxygen produced annually on earth. These aquatic organisms likely derived from a secondary endosymbiosis event, and they display peculiar genomic and structural features that reflect their chimeric origin. Diatoms were one of the first models of cell division and these early studies revealed a range of interesting features including a unique acentriolar microtubule-organising centre. Unfortunately, almost nothing is known at the molecular level, in contrast to the advances in other experimental organisms. Recently the full genome sequences of two diatoms have been annotated and molecular tools have been developed. These resources offer new possibilities to re-investigate the mechanisms of cell division in diatoms by recruiting information from more intensively studied organisms. A renaissance of the topic is further justified by the current interest in diatoms as a source of biofuels and for understanding massive diatom proliferation events in response to environmental stimuli. [source] Species concepts and floras: what are species for?BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2008SANDRA KNAPP In 1992, in a special paper in the American Journal of Botany, Ernst Mayr attempted to ,prove' the biological species concept (BSC) worked as well in plants as it did in animals by analyzing the flora of the Concord region of northern Massachusetts. He concluded that there were minimal difficulties when applying the BSC for the plants of this particular area, and concluded that botanists were misguided in not accepting the BSC. He suggested that what he called ,typological' thinking was prevalent in the taxonomic community, and that this was a factor in botanical resistance to the BSC. Typology, as defined by Mayr in his 1992 foray into botany, is to a certain extent a straw-man and, by the late 20th Century, no longer a way of thinking in widespread use in the taxonomic community in any organismal group. Here, I examine his analysis in the light of current interest in plant diversity. Species can be characterized as hypotheses about the distribution of variation in nature, subject to test with new data of many kinds. Species concepts like the BSC, although of interest philosophically and to researchers looking at mechanisms of speciation, may actually get in the way of achieving a baseline understanding of the diversity of life on Earth. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 95, 17,25. [source] | ||||||||||||||||||||||||||||