Considerable Progress (considerable + progress)

Distribution by Scientific Domains
Distribution within Medical Sciences


Selected Abstracts


Mouse Th17 cells: Current understanding of their generation and regulation

EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 3 2009
Chen Dong
Abstract IL-17-expressing CD4+ T cells have been recently recognized as a new subset of Th cells, namely Th17 cells. Considerable progress has been made in understanding the developmental regulation of mouse Th17 cells. Here, I summarize this knowledge and discuss on the relationship of Th17 with regulatory and follicular Th cells. [source]


Neuropsychological correlates of hippocampal and rhinal cortex volumes in patients with mesial temporal sclerosis

HIPPOCAMPUS, Issue 8 2003
Catherine E. O'Brien
Abstract Considerable progress has been made toward understanding the function of the primate rhinal cortex, comprising the entorhinal (ErC) and perirhinal (PrC) cortices. However, translating animal models to human memory has been limited by the technological problems associated with characterizing neural structures in vivo. Functional correlates of hippocampal and rhinal cortex volume changes were examined in a sample of 61 temporal lobe epilepsy patients with mesial temporal sclerosis (MTS; 33 left, 28 right). Patients were administered the Wechsler Adult Intelligence Scale (revised or third edition), the Wechsler Memory Scale (revised or third edition), and a spatial maze task. Neuropsychological data, together with rhinal cortex and hippocampal volumes, collected in our earlier study (O'Brien CE, Bowden SC, Whelan G, Cook MJ, unpublished observations), were analyzed using multiple regression. The only significant predictor of verbal memory function was the difference score between the volume of left hippocampus and the left PrC. Spatial maze scores were predicted by the bilateral sum of ErC volume. The difference score between the left hippocampus and left PrC volumes was the most powerful predictor of verbal episodic memory. Right hippocampal volume was not a significant predictor of nonverbal episodic memory. Verbal and nonverbal semantic memory were not significantly predicted by any combination of rhinal cortex structures. This quantitative study suggests a lateralized or material-specific memory function for the left hippocampus and left PrC, in contrast to the bilateral role of the ErC. The left hippocampus and left PrC appear to act on verbal memory function through an opposing relationship. Finally, differentiation between hippocampal and subhippocampal components in terms of episodic and semantic memory, respectively, could not be supported by the current data. © 2003 Wiley-Liss, Inc. [source]


The role of the preBCR, the interleukin-7 receptor, and homotypic interactions during B-cell development

IMMUNOLOGICAL REVIEWS, Issue 1 2000
Angela Stoddart
Summary: Considerable progress has been made in defining intermediate stages in the process leading from stem cells to mature B cells. Cell-bound and secreted molecules direct the progression through these stages and regulate the selection of clones from which the immune repertoire emerges. In fact, a myriad of signals derived from B-cell progenitors themselves and the microenvironment in which they develop direct the differentiation process. These signals are provided by B-cell antigen receptors (BCR) and their surrogates, and by adhesion and cytokine receptors. The co-operation of these receptors to control survival, expansion, and differentiation of early B-cell progenitors is the topic of this review. Specifically, we will summarize recent findings from our laboratory demonstrating that preBCR expression lowers the threshold for interleukin (IL)-7 responsiveness. How signals initiated by these receptors may intersect at this critical point of B-cell selection will be discussed. At the stage following IL-7 responsiveness we have shown that interactions between B-cell progenitors themselves promote their differentiation to immunoglobulin-secreting B cells. We propose that one function of stromal cells, known to be central to B lymphopoiesis, is to promote critical preB,preB homotypic interactions and ensuing signals. [source]


Molecular relaxation and metalloenzyme active site modeling

INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 4-5 2002
James W. Whittaker
Abstract Metalloenzymes represent a broad class of important biomolecules containing an essential metal ion cofactor in their catalytic active sites, forming biologic metal complexes that perform a wide range of important functions: activation of small molecules (O2, N2, H2, CO), atom transfer chemistry, and the control of oxidation equivalents. The structures of many metalloenzyme active sites have been defined by X-ray crystallography, revealing transition metal ions in unique low-symmetry environments. These bioinorganic complexes present significant challenges for computational studies aimed at going beyond crystal structures to develop a detailed understanding of the catalytic mechanisms. Considerable progress has been made in the theoretical characterization of these sites in recent years, supported by the availability of efficient computational tools, in particular density functional methods. However, the ultimate success of a theoretical model depends on a number of factors independent of the specific computational method used, including the quality of the initial structural data, the identification of important environmental perturbations and constraints, and experimental validation of theoretical predictions. We explore these issues in detail and illustrate the effects of molecular relaxation in calculations of two metalloenzymes, manganese superoxide dismutase and galactose oxidase. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002 [source]


Host-plant preference and oviposition responses of the sorghum midge, Stenodiplosis sorghicola (Coquillett) (Dipt., Cecidomyiidae) towards wild relatives of sorghum

JOURNAL OF APPLIED ENTOMOLOGY, Issue 3 2001
Sharma
Sorghum midge, Stenodiplosis (Contarinia) sorghicola (Coquillett) is an important pest of grain sorghum world-wide. Considerable progress has been made in screening and breeding for resistance to sorghum midge. However, some of the sources of resistance have become susceptible to sorghum midge in Kenya, in eastern Africa. Therefore, the wild relatives of Sorghum bicolor were studied as a possible source of new genes conferring resistance to sorghum midge. Midge females did not lay eggs in the spikelets of Sorghum amplum, Sorghum bulbosum, and Sorghum angustum compared to 30% spikelets with eggs in Sorghum halepense when infested with five midge females per panicle under no-choice conditions. However, one egg was laid in S. amplum when infested with 50 midges per panicle. A larger number of midges were attracted to the odours from the panicles of S. halepense than to the panicles of Sorghum stipoideum, Sorghum brachypodum, S.angustum, Sorghum macrospermum, Sorghum nitidium, Sorghum laxiflorum, and S. amplum in dual-choice olfactometer tests. The differences in midge response to the odours from S. halepense and Sorghum intrans were not significant. Under multi-choice conditions, when the females were also allowed a contact with the host, more sorghum midge females were attracted to the panicles of S. bicolor compared with S. amplum, S. angustum, and S. halepense. In another test, numerically more midges responded to the panicles of IS 10712 compared with S. halepense, whereas the differences in midge response to the panicles of ICSV 197 (S. bicolor) and S. halepense were not apparent, indicating that S. halepense is as attractive to sorghum midge females as S. bicolor. The wild relatives of sorghum (except S. halepense) were not preferred for oviposition, and they were also less attractive to the sorghum midge females. Thus, wild relatives of sorghum can prove to be an alternative source of genes for resistance to sorghum midge. [source]


Magnetic resonance imaging for ischemic heart disease

JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 1 2007
Hajime Sakuma MD
Abstract Cardiac MRI has long been recognized as an accurate and reliable means of evaluating cardiac anatomy and ventricular function. Considerable progress has been made in the field of cardiac MRI, and cardiac MRI can provide accurate evaluation of myocardial ischemia and infarction (MI). Late gadolinium (Gd)-enhanced MRI can clearly delineate subendocardial infarction, and the assessment of transmural extent of infarction on late enhanced MRI has been shown to be useful in predicting functional recovery of dysfunctional myocardium in patients after MI. Stress first-pass contrast-enhanced (CE) myocardial perfusion MRI can be used to detect subendocardial ischemia, and recent studies have demonstrated the high diagnostic accuracy of stress myocardial perfusion MRI for detecting significant coronary artery disease (CAD). Free-breathing, whole-heart coronary MR angiography (MRA) was recently introduced as a method that can provide visualization of all three major coronary arteries within a single three-dimensional (3D) acquisition. With further improvements in MRI techniques and the establishment of a standardized study protocol, cardiac MRI will play a pivotal role in managing patients with ischemic heart disease. J. Magn. Reson. Imaging 2007;26:3,13. © 2007 Wiley-Liss, Inc. [source]


Conceptual and Design Essentials for Evaluating Mechanisms of Change

ALCOHOLISM, Issue 2007
Matthew K. Nock
Background:, Considerable progress has been made toward the development of evidence-based treatments for a wide range of psychological disorders; however, little is known about the mechanisms through which these treatments actually lead to clinical change. Although the use of traditional randomized controlled treatment designs and tests of statistical mediation have significantly advanced understanding of psychological treatments, they are insufficient to test mechanisms of change. Method:, This article outlines the conceptual and methodological requirements for evaluating mechanisms of change, highlights the importance of such a focus, and offers specific recommendations for research aimed at elucidating change mechanisms. Results and Conclusions:, Conceptualizing and conducting studies that test mechanisms of change requires substantial modifications to traditional research designs, but doing so will significantly enhance scientific understanding as well as the efficiency and effectiveness of clinical interventions. [source]


Soil degradation by erosion

LAND DEGRADATION AND DEVELOPMENT, Issue 6 2001
R. Lal
Abstract Soil degradation by accelerated erosion is a serious problem and will remain so during the 21st century, especially in developing countries of the tropics and subtropics. Yet, its extent, severity, and economic and environmental impacts are debatable. Estimates of global and regional land area affected are tentative and subjective. Results of field measurements are often technique-dependent. Considerable progress has been made in modeling soil erosion, yet field validation of these models remains to be done for principal soils and ecoregions. Similar to the land area affected, estimates of erosional impacts on crop yield, productivity and soil quality are tentative and subjective. Further, erosion-induced losses on crop yield are scale-dependent because of the compensatory beneficial effects on yields from depositional sites, and technology-dependent because of the masking effects of input such as fertilizers and irrigation. Erosion caused changes in soil carbon dynamics and non-point source water pollution are important environmental impacts. While erosion (e.g., detachment and transport) can lead to emission of trace gases into the atmosphere, deposition can bury and sequester some of the carbon. In addition to improving the database on the land area affected, there is also a need to assess erosional impacts on productivity and soil C balance at the watershed, regional, and global scale. Copyright © 2001 John Wiley & Sons, Ltd. [source]


Ion channel remodeling in gastrointestinal inflammation

NEUROGASTROENTEROLOGY & MOTILITY, Issue 10 2010
H. I. Akbarali
Abstract Background,Gastrointestinal inflammation significantly affects the electrical excitability of smooth muscle cells. Considerable progress over the last few years have been made to establish the mechanisms by which ion channel function is altered in the setting of gastrointestinal inflammation. Details have begun to emerge on the molecular basis by which ion channel function may be regulated in smooth muscle following inflammation. These include changes in protein and gene expression of the smooth muscle isoform of L-type Ca2+ channels and ATP-sensitive K+ channels. Recent attention has also focused on post-translational modifications as a primary means of altering ion channel function in the absence of changes in protein/gene expression. Protein phosphorylation of serine/theronine or tyrosine residues, cysteine thiol modifications, and tyrosine nitration are potential mechanisms affected by oxidative/nitrosative stress that alter the gating kinetics of ion channels. Collectively, these findings suggest that inflammation results in electrical remodeling of smooth muscle cells in addition to structural remodeling. Purpose,The purpose of this review is to synthesize our current understanding regarding molecular mechanisms that result in altered ion channel function during gastrointestinal inflammation and to address potential areas that can lead to targeted new therapies. [source]


Systemin-dependent salinity tolerance in tomato: evidence of specific convergence of abiotic and biotic stress responses

PHYSIOLOGIA PLANTARUM, Issue 1 2010
Francesco Orsini
Plants have evolved complex mechanisms to perceive environmental cues and develop appropriate and coordinated responses to abiotic and biotic stresses. Considerable progress has been made towards a better understanding of the molecular mechanisms of plant response to a single stress. However, the existence of cross-tolerance to different stressors has proved to have great relevance in the control and regulation of organismal adaptation. Evidence for the involvement of the signal peptide systemin and jasmonic acid in wound-induced salt stress adaptation in tomato has been provided. To further unravel the functional link between plant responses to salt stress and mechanical damage, transgenic tomato (Lycopersicon esculentum Mill.) plants constitutively expressing the prosystemin cDNA have been exposed to a moderate salt stress. Prosystemin over-expression caused a reduction in stomatal conductance. However, in response to salt stress, prosystemin transgenic plants maintained a higher stomatal conductance compared with the wild-type control. Leaf concentrations of abscissic acid (ABA) and proline were lower in stressed transgenic plants compared with their wild-type control, implying that either the former perceived a less stressful environment or they adapted more efficiently to it. Consistently, under salt stress, transgenic plants produced a higher biomass, indicating that a constitutive activation of wound responses is advantageous in saline environment. Comparative gene expression profiling of stress-induced genes suggested that the partial stomatal closure was not mediated by ABA and/or components of the ABA signal transduction pathway. Possible cross-talks between genes involved in wounding and osmotic stress adaptation pathways in tomato are discussed. [source]


Convective-scale assimilation of radar data: progress and challenges

THE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 613 2005
Juanzhen Sun
Abstract Active research has been carried out in recent years to assimilate high-resolution observations into numerical models to improve precipitation forecasting. Considerable progress has been made although great scientific and technological challenges still exist. This paper reviews techniques used in convective-scale data assimilation research. Experiences in the assimilation of radar observations into high-resolution numerical models are presented. A number of future challenges in convective-scale data assimilation are discussed. Copyright © 2005 Royal Meteorological Society [source]


Histones and histone modifications in protozoan parasites

CELLULAR MICROBIOLOGY, Issue 12 2006
William J. Sullivan Jr
Summary Protozoan parasites are early branching eukaryotes causing significant morbidity and mortality in humans and livestock. Single-celled parasites have evolved complex life cycles, which may involve multiple host organisms, and strategies to evade host immune responses. Consequently, two key aspects of virulence that underlie pathogenesis are parasite differentiation and antigenic variation, both of which require changes in the expressed genome. Complicating these requisite alterations in the parasite transcriptome is chromatin, which serves as a formidable barrier to DNA processes including transcription, repair, replication and recombination. Considerable progress has been made in the study of chromatin dynamics in other eukaryotes, and there is much to be gained in extending these analyses to protozoan parasites. Much of the work completed to date has focused on histone acetylation and methylation in the apicomplexans and trypanosomatids. As we describe in this review, such studies provide a unique vantage point of the evolutionary picture of eukaryotic cell development, and reveal unique phenomena that could be exploited pharmacologically to treat protozoal diseases. [source]


Heterogeneity, Group Size and Collective Action: The Role of Institutions in Forest Management

DEVELOPMENT AND CHANGE, Issue 3 2004
Amy R. Poteete
Collective action for sustainable management among resource-dependent populations has important policy implications. Despite considerable progress in identifying factors that affect the prospects for collective action, no consensus exists about the role played by heterogeneity and size of group. The debate continues in part because of a lack of uniform conceptualization of these factors, the existence of non-linear relationships, and the mediating role played by institutions. This article draws on research by scholars in the International Forestry Resources and Institutions (IFRI) research network which demonstrates that some forms of heterogeneity do not negatively affect some forms of collective action. More importantly, IFRI research draws out the interrelations among group size, heterogeneity, and institutions. Institutions can affect the level of heterogeneity or compensate for it. Group size appears to have a non-linear relationship to at least some forms of collective action. Moreover, group size may be as much an indicator of institutional success as a precondition for such success. [source]


The L1-CAM, Neuroglian, functions in glial cells for Drosophila antennal lobe development

DEVELOPMENTAL NEUROBIOLOGY, Issue 8 2008
Weitao Chen
Abstract Although considerable progress has been made in understanding the roles of olfactory receptor neurons (ORNs) and projection neurons (PNs) in Drosophila antennal lobe (AL) development, the roles of glia have remained largely mysterious. Here, we show that during Drosophila metamorphosis, a population of midline glial cells in the brain undergoes extensive cellular remodeling and is closely associated with the collateral branches of ORN axons. These glial cells are required for ORN axons to project across the midline and establish the contralateral wiring in the ALs. We find that Neuroglian (Nrg), the Drosophila homolog of the vertebrate cell adhesion molecule, L1, is expressed and functions in the midline glial cells to regulate their proper development. Loss of Nrg causes the disruption in glial morphology and the agenesis of the antennal commissural tract. Our genetic analysis further demonstrates that the functions of Nrg in the midline glia require its ankyrin-binding motif. We propose that Nrg is an important regulator of glial morphogenesis and axon guidance in AL development. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2008. [source]


Characterizing the ADHD phenotype for genetic studies

DEVELOPMENTAL SCIENCE, Issue 2 2005
Jim Stevenson
The genetic study of ADHD has made considerable progress. Further developments in the field will be reliant in part on identifying the most appropriate phenotypes for genetic analysis. The use of both categorical and dimensional measures of symptoms related to ADHD has been productive. The use of multiple reporters is a valuable feature of the characterization of psychopathology in children. It is argued that the use of aggregated measures to characterize the ADHD phenotype, particularly to establish its pervasiveness, is desirable. The recognition of the multiple comorbidities of ADHD can help to isolate more specific genetic influences. In relation to both reading disability and conduct disorder there is evidence that genes may be involved in the comorbid condition that are different from pure ADHD. To date, progress with the investigation of endophenotypes for ADHD has been disappointing. It is suggested that extending such studies beyond cognitive underpinnings to include physiological and metabolic markers might facilitate progress. [source]


Diagnosing and treating diabetic foot infections

DIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue S1 2004
Benjamin A. Lipsky
Abstract Foot infections are a common, complex and costly complication of diabetes. We have made considerable progress in establishing consensus definitions for defining infection. Similarly, we have learned much about the appropriate ways to diagnose both soft tissue and bone infections. Accompanying these advances have been improvements in our knowledge of the proper approaches to antibiotic (and surgical) therapy for diabetic foot infections. Furthermore, investigators have explored the value of various adjunctive therapies, especially granulocyte colony stimulating factors and hyperbaric oxygen, for improving outcomes. This paper presents a summary of a minisymposium on infection of the diabetic foot that was held at the fourth International Symposium on the Diabetic Foot, in Noordwijkerhout, The Netherlands. Crown copyright 2004. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd. [source]


Aerial photosieving of exposed gravel bars for the rapid calibration of airborne grain size maps

EARTH SURFACE PROCESSES AND LANDFORMS, Issue 6 2010
Stephen J. Dugdale
Abstract In recent years, fluvial remote sensing has seen considerable progress in terms of methods capable of system scale characterisation of river catchments. One key development is automated grain size mapping. It has been shown that high resolution aerial photography can be used to automatically produce grain size maps over entire rivers. However, current aerial grain size mapping procedures all require field calibration data. The collection of such data can be costly and problematic in the case of remote areas. This paper presents a method developed to remove the need for field based calibration data. Called ,aerial photosieving', this method consists of using the same very high resolution aerial imagery intended for grain size map production to visually measure particle sizes on-screen in order to provide calibration data. The paper presents a rigorous comparison of field-based photosieving calibration data and aerial photosieving calibration data. Statistical tests are used to demonstrate that aerial photosieving gives similar results when compared with field-based data with only a slight systematic overprediction. The new aerial photosieving method therefore simplifies the overall procedure required for the production of grain size maps and thus improves the cost-effectiveness and potential availability of this new fluvial remote sensing technology. Copyright © 2010 John Wiley &Sons, Ltd. [source]


Output-only structural identification in time domain: Numerical and experimental studies

EARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 4 2008
M. J. Perry
Abstract By identifying changes in stiffness parameters, structural damage can be detected and monitored. Although considerable progress has been made in this research area, many challenges remain in achieving robust structural identification based on incomplete and noisy measurement signals. The identification task is made even more difficult if measurement of input force is to be eliminated. To this end, an output-only structural identification strategy is proposed to identify unknown stiffness and damping parameters. A non-classical approach based on genetic algorithms (GAs) is adopted. The proposed strategy makes use of the recently developed GA-based method of search space reduction, which has shown to be able to accurately and reliably identify structural parameters from measured input and output signals. By modifying the numerical integration scheme, input can be computed as the parameter identification task is in progress, thereby eliminating the need to measure forces. Numerical and experimental results demonstrate the power of the strategy in accurate and efficient identification of structural parameters and damage using only incomplete acceleration measurements. Copyright © 2007 John Wiley & Sons, Ltd. [source]


Continuities and changes in self-change research

ADDICTION, Issue 9 2010
Harald Klingemann
ABSTRACT Aims A substantial literature demonstrates that natural recoveries from substance use disorders not only occur but are a common pathway to recovery. This article reviews selectively and comments on the current state-of-the-art in natural recovery research. Methods Basic concepts in natural recovery research are presented, and topical and methodological trends and changes in self-change research over time are discussed. Conclusions Although considerable progress has occurred in natural recovery research, several topics deserving of further research are identified, and implications for policy practice are discussed. [source]


The New Basel Capital Adequacy Framework

ECONOMIC NOTES, Issue 3 2001
Giovanni Carosio
The Basel Committee on Banking Supervision is about to publish a second consultative paper on the reform of the 1988 Accord on capital adequacy. The new document takes into account the comments received on the June 1999 consultative paper, gives a much clearer picture of crucial aspects of the reform that were only presented in very general terms in the earlier paper, and quantifies most of the parameters that will be needed to calculate the capital requirements. Although considerable progress has been made towards reaching operational status, several aspects of the regulation still need to be worked out and further reflection is needed on the best way to tackle some of the more problematic issues that have been identified. Comments, suggestions, criticisms such as today's seminar will certainly provide, are therefore most welcome. There will be time to take them into consideration, as the final draft of the regulation will not be completed before the end of 2001. My presentation is divided into three parts: I first illustrate the objectives of the reform, then describe the essential features of the new regulation, and finally discuss the possible impacts of its implementation. (J.E.L. G21, G28). [source]


Exploring the Phospholipid Biosynthetic Pathways of Aspergillus fumigatus by Computational Genome Analysis

ENGINEERING IN LIFE SCIENCES (ELECTRONIC), Issue 6 2005
H. Do
Abstract Aspergillus fumigatus causes a wide range of diseases that include mycotoxicosis, allergic reactions and systematic diseases (invasive aspergillosis) with high mortality rates. In recent years, considerable progress in the genome sequencing of this fungus has been made by an international consortium, which includes the Wellcome Trust Sanger Institute (UK) and the Institute for Genome Research (USA). A tenfold whole genome shotgun sequence assembly of A. fumigatus has been made publicly available. In this study, it was attempted to identify the genes related to the phospholipid biosynthesis from the A. fumigatus genome by a gene prediction program (GlimmerM) and to reconstruct the metabolic pathway for phospholipids of A. fumigatus. Fifteen genes related to phospholipid pathway were identified in the A. fumigatus genomic sequence. The open reading frames predicted by GlimmerM showed a high amino acid sequence similarity with the other fungal phospholipid biosynthetic genes and well-conserved functional domains. The obtained results also demonstrated that the reconstructed pathway of A. fumigatus in phospholipid biosynthesis was very similar to that of other fungi such as Saccharomyces cerevisiae, Schizosaccharomyces pombe, Candida albicans, and Neurospora crassa. Therefore it is postulated that the antifungal drugs targeted for the biosynthesis of phospholipids could also be effective against A. fumigatus. [source]


Strategic environmental awakening: European progress in regional environmental integration

ENVIRONMENTAL POLICY AND GOVERNANCE, Issue 2 2001
Keith Clement
In the EU Structural Funds, integrating environment and regional economic development is a challenge that is progressively being met. From a beginning characterized by conflict between these two themes, considerable progress has been made in successive rounds of programmes, accompanied by a gradual raising of awareness and the development of new mechanisms for integration. This progress has been supported by environmental guidance from the European Commission, with handbooks designed to raise new ideas and suggest innovative ways of approaching the task. Current programmes incorporate extensive environmental profiles to support programme development, and new methods of combining both horizontal and vertical integration show considerable promise for the realization of environmental objectives in programme implementation. To facilitate further integration, priorities for research include the role for environmental strategies, the production of an index of environmental integration, the identification of measurable environmental indicators and confirmation that sustainable development is acting as a catalyst for environmental gain. Copyright © 2001 John Wiley & Sons, Ltd and ERP Environment [source]


Ascending visceral regulation of cortical affective information processing

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 8 2003
Gary G. Berntson
Abstract Over a century ago, William James proposed that strong emotions represent the perceptual consequences of somato-visceral feedback. Although the strong form of this conception is no longer viable, considerable evidence has accumulated indicating a range of visceral influences on higher neurobehavioural processes. This literature has only recently begun to consolidate, because earlier reports generally remained at the demonstration level, and pathways and mechanisms for such influences were uncertain. Recently, specific effects of visceral feedback have become apparent on cortical activity, cerebral auditory-evoked responses, anxiety, memory and behavioural aspects of immunological sickness. Moreover, considerable progress has been made recently in determining the specific neural pathways and systems underlying these actions, especially the role of noradrenergic projections from the nucleus of the tractus solitarius and the locus coeruleus to the amygdala in memory processes, and to the basal forebrain in the processing of anxiety-related information. The present paper highlights selected recent findings in this area, and outlines relevant structures and pathways involved in the ascending visceral influence on higher neurobehavioural processes. [source]


Pathophysiology of pruritus in atopic dermatitis: an overview

EXPERIMENTAL DERMATOLOGY, Issue 1 2002
Sonja Ständer
Abstract: Pruritus is an essential feature of atopic dermatitis (AD) and the diagnosis of active AD cannot be made without the history of itching. Because of the high impact on life quality, most of the patients measure the severity of eczema by the intensity of pruritus rather than appearance of skin lesions. However, although pruritus is a cardinal symptom of AD, its mechanism and association with the cutaneous nervous system is not completely understood. Recently, a considerable progress has been achieved in clarifying the complex pathophysiology of pruritus in AD. As a cutaneous sensory perception, itch requires excitation of neuropeptide-containing free nerve endings of unmyelinated nociceptor fibers. It is well known that histamine and acetylcholine provoke itch by direct binding to ,itch receptors' and several mediators such as neuropeptides, proteases or cytokines indirectly via histamine release. Interestingly, some variations of these complex mechanisms could be demonstrated in patients with AD. This review highlights the recent knowledge of different mechanisms which may be involved in regulating pruritus in patients with AD potentially leading to new therapeutic applications for the treatment of itch in AD. [source]


Cold-Induced Recruitment of Brown Adipose Tissue Thermogenesis

EXPERIMENTAL PHYSIOLOGY, Issue 1 2003
Martin Klingenspor
Non-shivering thermogenesis in brown adipose tissue is the main mechanism for thermoregulatory heat production in small mammals and newborns. During cold acclimation the sympathetic innervation triggers the recruitment of brown adipose tissue by hyperplasia, which involves the proliferation and differentiation of precursor cells, and by hypertrophy of mature brown adipocytes. Mitochondrial biogenesis and increased synthesis of the uncoupling protein 1 (UCP-1) are hallmarks of the thermogenic recruitment process. The severalfold increase of mitochondrial protein content during cold acclimation recruits a large capacity for oxidative phosphorylation. However, UCP-1 increases proton leakage across the inner membrane of brown adipocyte mitochondria and thereby dissipates proton motive force as heat instead of ATP synthesis. During recent years considerable progress has been achieved in the analysis of transcriptional mechanisms controlling Ucp1 gene expression. However, so far only little is known about the molecular basis of cold-induced mitochondrial biogenesis in brown adipose tissue. [source]


Challenges and Progress in High-Throughput Screening of Polymer Mechanical Properties by Indentation

ADVANCED MATERIALS, Issue 35 2009
Johannes M. Kranenburg
Abstract Depth-sensing or instrumented indentation is an experimental characterization approach well-suited for high-throughput investigation of mechanical properties of polymeric materials. This is due to both the precision of force and displacement, and to the small material volumes required for quantitative analysis. Recently, considerable progress in the throughput (number of distinct material samples analyzed per unit time) of indentation experiments has been achieved, particularly for studies of elastic properties. Future challenges include improving the agreement between various macroscopic properties (elastic modulus, creep compliance, loss tangent, onset of nonlinear elasticity, energy dissipation, etc.) and their counterpart properties obtained by indentation. Sample preparation constitutes a major factor for both the accuracy of the results and the speed and efficiency of experimental throughput. It is important to appreciate how this processing step may influence the mechanical properties, in particular the onset of nonlinear elastic or plastic deformation, and how the processing may affect the agreement between the indentation results and their macroscopic analogues. [source]


The Second Generation in Germany: Between School and Labor Market,

INTERNATIONAL MIGRATION REVIEW, Issue 4 2003
Susanne Worbs
The German "mode of integration" after World War II has been to include migrants and their offspring into general societal institutions. This can be stated despite differences between federal states in some aspects of migrant integration (e.g., the educational sector). Migrant children normally attend the same schools and classes as their German age peers, they participate in the dual system of vocational training, and there are only a few limitations in labor market access. The second generation in Germany consists mainly of children of the "guestworkers" recruited in southern and southeastern European countries from the 1950s onwards. It is not easy to obtain information about their numbers and their socioeconomic position, as most statistical data distinguish only between foreigners and Germans. The achieved integration status of the second generation varies between areas: obvious problems in the educational system go along with considerable progress in the vocational training system and in the labor market. Children of Turkish migrants are the most disadvantaged group among the second generation. [source]


Corporate Governance in India

JOURNAL OF APPLIED CORPORATE FINANCE, Issue 1 2008
Rajesh Chakrabarti
The Indian corporate governance system has both supported and held back India's ascent to the top ranks of the world's economies. While on paper the country's legal system provides some of the best investor protection in the world, enforcement is a major problem, with overburdened courts and significant corruption. Ownership remains concentrated and family business groups continue to be the dominant business model, with significant pyramiding and evidence of tunneling activity that transfers cash flow and value from minority to controlling shareholders. But for all its shortcomings, Indian corporate governance has taken major steps toward becoming a system capable of inspiring confidence among institutional and, increasingly, foreign investors. The Securities and Exchanges Board of India (SEBI), which was established as part of the comprehensive economic reforms launched in 1991, has made considerable progress in becoming a rigorous regulatory regime that helps ensure transparency and fair practice. And the National Stock Exchange of India, also established as part of the reforms, now functions with enough efficiency and transparency to be generating the third-largest number of trades in the world, just behind the NASDAQ and NYSE. Among more recent changes, the enactment of Sarbanes,Oxley type measures in 2004,which includes protections for minority shareholders in family- or "promoter"-led businesses,has contributed to recent increases in institutional and foreign stock ownership. And while family- and government-controlled business groups continue to be the rule, India has also seen the rise of successful companies like Infosys that are free of the influence of a dominant family or group and have made the individual shareholder their central governance focus. [source]


Arrhythmogenic Right Ventricular Dyspiasia/Cardiomyopathy:

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 7 2000
Need for an International Registry.
Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy. Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is a heart muscle disease characterized by peculiar right ventricular involvement and electrical instability that precipitates ventricular arrhythmias and sudden death. The purpose of the present consensus report of the Study Group of the European Society of Cardiology and the Scientific Council on Cardiomyopathies of the World Heart Federation is to review the considerable progress in our understanding of the etiopathogenesis, morbid anatomy, and clinical presentation of ARVD/C since its first description in 1977. This article will focus on the important hut still unanswered issues, mostly regarding risk stratification, clinical outcome, and management of affected patients. Because ARVD/C is relatively uncommon and any one center may have experience with only a few patients, an international registry is being established to accumulate information and enhance the numbers of patients that can be analyzed to answer the pending questions. The registry also will facilitate pathologic, molecular, and genetics research on the etiology and pathogenesis of the disease. Furthermore, availability of an international database will enhance awareness of this largely unrecognized condition among the medical community. Physicians are encouraged to enroll patients in the International Registry of ARVD/C. [source]


Partial uniqueness in CANDECOMP/PARAFAC

JOURNAL OF CHEMOMETRICS, Issue 1 2004
Jos M. F. ten Berge
Abstract A key property of CANDECOMP/PARAFAC is the essential uniqueness it displays under certain conditions. It has been known for a long time that, when these conditions are not met, partial uniqueness may remain. Whereas considerable progress has been made in the study of conditions for uniqueness, the study of partial uniqueness has lagged behind. The only well known cases are those of overfactoring, when more components are extracted than are required for perfect fit, and those cases where the data do not have enough system variation, resulting in proportional components for one or more modes. The present paper deals with partial uniqueness in cases where the smallest number of components is extracted that yield perfect fit. For the case of K×K×2 arrays of rank K, randomly sampled from a continuous distribution, it is shown that partial uniqueness, with some components unique and others differing between solutions, arises with probability zero. Also, a closed-form CANDECOMP/PARAFAC solution is derived for 5×3×3 arrays when these happen to have rank 5. In such cases, any two different solutions share four of the five components. This phenomenon will be traced back to a sixth degree polynomial having six real roots, any five of which can be picked to construct a solution. Copyright © 2004 John Wiley & Sons, Ltd. [source]