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Major Role (major + role)
Kinds of Major Role Selected AbstractsLessons from History: Why Race and Ethnicity Have Played a Major Role in Biomedical ResearchTHE JOURNAL OF LAW, MEDICINE & ETHICS, Issue 3 2006Troy Duster Ph.D. Before any citizen enters the role of scientist, medical practitioner, lawyer, epidemiologist, and so on, each and all grow up in a society in which the categories of human differentiation are folk categories that organize perceptions, relations, and behavior. That was true during slavery, during Reconstruction, the eugenics period, the two World Wars, and is no less true today. While every period understandably claims to transcend those categories, medicine, law, and science are profoundly and demonstrably influenced by the embedded folk notions of race and ethnicity. [source] Lipophilicity Plays a Major Role in Modulating the Inhibition of Monoamine Oxidase B by 7-Substituted CoumarinsCHEMISTRY & BIODIVERSITY, Issue 2 2006Angelo Carotti Abstract A series of coumarin derivatives (1,22), bearing at the 7-position ether, ketone, ester, carbamate, or amide functions of varying size and lipophilicity, were synthesized and investigated for their in vitro monoamine oxidase-A and -B (MAO-A and -B) inhibitory activities. Most of the compounds acted preferentially as MAO-B inhibitors, with IC50 values in the micromolar to low-nanomolar range. A structure,activity-relationship (SAR) study highlighted lipophilicity as an important property modulating the MAO-B inhibition potency of 7-substituted coumarins, as shown by a linear correlation (n=20, r2=0.72) between pIC50 and calculated log P values. The stability of ester-containing coumarin derivatives in rat plasma provided information on factors that either favor (lipophilicity) or decrease (steric hindrance) esterase-catalyzed hydrolysis. Two compounds (14 and 22) were selected to investigate how lipophilicity and enzymatic stability may affect in vivo MAO activities, as assayed ex vivo in rat. The most-potent and -selective MAO-B inhibitor 22 (=7-[(3,4-difluorobenzyl)oxy]-3,4-dimethyl-1-benzopyran-2(2H)-one) within the examined series significantly inhibited (>60%) ex vivo rat-liver and striatal MAO-B activities 1,h after intraperitoneal administration of high doses (100 and 300,,mol kg,1), revealing its ability to cross the blood,brain barrier. At the same doses, liver and striatum MAO-A was less inhibited in vivo, somehow reflecting MAO-B selectivity, as assessed in vitro. In contrast, the metabolically less stable derivative 14, bearing an isopropyl ester in the lateral chain, had a weak effect on hepatic MAO-B activity in vivo, and none on striatal MAO-B, but, surprisingly, displayed inhibitory effects on MAO-A in both peripheral and brain tissues. [source] Evaluation of Uncertainties Associated with Geocoding TechniquesCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 3 2004Hassan A. Karimi Geocoded data play a major role in numerous engineering applications such as transportation and environmental studies where geospatial information systems (GIS) are used for spatial modeling and analysis as they contain spatial information (e.g., latitude and longitude) about objects. The information that a GIS produces is impacted by the quality of the geocoded data (e.g., coordinates) stored in its database. To make appropriate and reasonable decisions using geocoded data, it is important to understand the sources of uncertainty in geocoding. There are two major sources of uncertainty in geocoding, one related to the database that is used as a reference data set to geocode objects and one related to the interpolation technique used. Factors such as completeness, correctness, consistency, currency, and accuracy of the data in the reference database contribute to the uncertainty of the former whereas the specific logic and assumptions used in an interpolation technique contribute to the latter. The primary purpose of this article is to understand uncertainties associated with interpolation techniques used for geocoding. In doing so, three geocoding algorithms were used and tested and the results were compared with the data collected by the Global Positioning System (GPS). The result of the overall comparison indicated no significant differences between the three algorithms. [source] Role of ancillary techniques in diagnosing and subclassifying non-Hodgkin's lymphomas on fine needle aspiration cytologyCYTOPATHOLOGY, Issue 5 2006P. DeyArticle first published online: 8 SEP 200 Non-Hodgkin's lymphomas (NHL) are tumours of the lymphoid cells. During the process of development of lymphoid cells, neoplasia may evolve at any point. Neoplastic cells usually carry the imprint of cell of origin at the stage of origin. Various types of NHL may have similar morphology with wide variation in origin, immunophenotype and other biological features. Different ancillary laboratory techniques may help to overcome the limitations of morphology in this aspect. The commonly used ancillary techniques in lymphomas are immunocytochemistry (IC), flow cytometry, Southern blot (SB) technique, polymerase chain reaction (PCR) and fluorescent in situ hybridization (FISH). In addition, laser scanning cytometry (LSC) and DNA microarray technologies are in the research phase. Various laboratory techniques are used for immunophenotyping, demonstration of monoclonality, identification of chromosomal translocation, assessment of cell kinetics and expression of mRNA in the tumour cells. Flow cytometry helps in rapid immunophenotying of NHL and it has an added advantage over IC in recognizing the co-expression of CD markers. Fine needle aspiration cytology (FNAC) combined with flow immunophenotyping may help us to diagnose and subclassify certain NHLs, such as follicular lymphoma and mantle cell lymphoma, which were previously recognized as pure morphological entities. Loss of morphology is one of the important limitations of flow cytometry. LSC can overcome this limitation by studying morphology along with the immunophenotyping pattern of individual cells. Chromosomal changes in NHL can be identified by SB, PCR and FISH. Molecular diagnosis of NHL helps in diagnosis, subclassification, prognostic assessment and even in planning of therapy. DNA microarray is a relatively newer and promising technology. It gives information about the expression of several thousands of genes in a tumour in a single experiment. In the near future, FNAC combined with ancillary techniques may play a major role in diagnosis, subclassification and management of lymphomas. [source] Role of the Na+/Ca2+ exchanger in calcium homeostasis and human sperm motility regulationCYTOSKELETON, Issue 2 2006Zoltán Krasznai Abstract A number of cell functions, such as flagellar beating, swimming velocity, acrosome reaction, etc., are triggered by a Ca2+ influx across the cell membrane. For appropriate physiological functions, the motile human sperm maintains the intracellular free calcium concentration ([Ca2+]i) at a submicromolar level. The objective of this study was to determine the role of the Na+/Ca2+ exchanger (NCX) in the maintenance of [Ca2+]i in human spermatozoa. Spermatozoa maintained in extracellular medium containing ,1 ,M Ca2+ exhibited motility similar to that of the control. In addition to several calcium transport mechanisms described earlier, we provide evidence that the NCX plays a crucial role in the maintenance of [Ca2+]i. Three chemically unrelated inhibitors of the NCX (bepridil, DCB (3,,4, -dichlorobenzamil hydrochloride), and KB-R7943) all blocked human sperm motility in a dose and incubation time dependent manner. The IC50 values for bepridil, DCB, and KB-R7943 were 16.2, 9.8, and 5.3 ,M, respectively. The treatment with the above-mentioned blockers resulted in an elevated [Ca2+]i and a decreased [Na+]i. The store-operated calcium channel (SOCC) inhibitor SKF 96365 also blocked the sperm motility (IC50 = 2.44 ,M). The presence of the NCX antigen in the human spermatozoa was proven by flow cytometry, confocal laser scanning microscopy, and immunoblotting techniques. Calcium homeostasis of human spermatozoa is maintained by several transport proteins among which the SOCC and the NCX may play a major role. Cell Motil. Cytoskeleton 2006. © 2005 Wiley-Liss, Inc. [source] Effect of storage media on human periodontal ligament cell apoptosisDENTAL TRAUMATOLOGY, Issue 1 2008Mónica M. Chamorro However, the mechanisms by which different storage conditions alter the functional status of PDL cells have not been determined. The purpose of the present study was to investigate, in vitro, the level of programed cell death or apoptosis in a population of PDL cells following storage under different conditions. Primary human PDL cells were plated into 24-well-culture plates and allowed to attach for 24 h. Cells were then exposed for 1 h to milk, Hank's balanced salt solution (HBSS), Soft Wear contact lens solution or Gatorade at room temperature or on ice. Culture medium was used as a negative control. Apoptosis was evaluated at 24, 48, and 72 h after treatment on quadruplicate samples by using the ST 160 ApopTag Fluorescein Direct In Situ Detection Kit. The total number of cells and the total number of apoptotic cells were counted. The results indicated that at 24 and 72 h, PDL treated with Gatorade and the contact lens solution displayed the highest percentages of apoptotic cells when compared with the other treatment groups at room temperature. Overall, cells treated on ice showed significantly lower levels of apoptosis when compared with treatments at room temperature. In conclusion, the results indicated that apoptosis plays a major role in cell death in cells treated with Gatorade and contact lens solutions in comparison to other storage solutions and that storage on ice can inhibit programed cell death. [source] Increased right amygdala volume in lithium-treated patients with bipolar I disorderACTA PSYCHIATRICA SCANDINAVICA, Issue 2 2010J. Usher Usher J, Menzel P, Schneider-Axmann T, Kemmer C, Reith W, Falkai P, Gruber O, Scherk H. Increased right amygdala volume in lithium-treated patients with bipolar I disorder. Objective:, The amygdala plays a major role in processing emotional stimuli. Fourteen studies using structural magnetic resonance imaging (MRI) have examined the amygdala volume in paediatric and adult patients with bipolar disorder (BD) compared with healthy controls (HC) and reported inconsistent findings. Lithium has been found to increase grey matter volume, and first evidence points towards an effect on regional brain volume such as the amygdala. Method:, We examined the amygdala volume of euthymic patients with BD treated with lithium (n = 15), without lithium (n = 24) and HC (n = 41) using structural MRI. Results:, Patients treated with lithium exhibited in comparison to HC a larger right absolute (+17.9%, P = 0.015) and relative (+18%, P = 0.017) amygdala volume. There was no significant difference in amygdala volume between patients without lithium treatment and HC. Conclusion:, Lithium appears to have a sustained effect on a central core region of emotional processing and should therefore be considered in studies examining BD. [source] The epidemiology of autistic spectrum disorders: is the prevalence rising?DEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 3 2002Lorna Wing Abstract For decades after Kanner's original paper on the subject was published in 1943, autism was generally considered to be a rare condition with a prevalence of around 2,4 per 10,000 children. Then, studies carried out in the late 1990s and the present century reported annual rises in incidence of autism in pre-school children, based on age of diagnosis, and increases in the age-specific prevalence rates in children. Prevalence rates of up to 60 per 10,000 for autism and even more for the whole autistic spectrum were reported. Reasons for these increases are discussed. They include changes in diagnostic criteria, development of the concept of the wide autistic spectrum, different methods used in studies, growing awareness and knowledge among parents and professional workers and the development of specialist services, as well as the possibility of a true increase in numbers. Various environmental causes for a genuine rise in incidence have been suggested, including the triple vaccine for measles, mumps and rubella (MMR]. Not one of the possible environmental causes, including MMR, has been confirmed by independent scientific investigation, whereas there is strong evidence that complex genetic factors play a major role in etiology. The evidence suggests that the majority, if not all, of the reported rise in incidence and prevalence is due to changes in diagnostic criteria and increasing awareness and recognition of autistic spectrum disorders. Whether there is also a genuine rise in incidence remains an open question. MRDD Research Reviews 2002;8:151,161. © 2002 Wiley-Liss, Inc. [source] Phylogeny of the teashirt-related zinc finger (tshz) gene family and analysis of the developmental expression of tshz2 and tshz3b in the zebrafishDEVELOPMENTAL DYNAMICS, Issue 3 2010Joana S. Santos Abstract The tshz genes comprise a family of evolutionarily conserved transcription factors. However, despite the major role played by Drosophila tsh during the development of the fruit fly, the expression and function of other tshz genes have been analyzed in a very limited set of organisms and, therefore, our current knowledge of these genes is still fragmentary. In this study, we perform detailed phylogenetic analyses of the tshz genes, identify the members of this gene family in zebrafish and describe the developmental expressions of two of them, tshz2 and tshz3b, and compare them with meis1, meis2.1, meis2.2, pax6a, and pax6b expression patterns. The expression patterns of these genes define a complex set of coexpression domains in the developing zebrafish brain where their gene products have the potential to interact. Developmental Dynamics 239:1010,1018, 2010. © 2010 Wiley-Liss, Inc. [source] Emx3 is required for the differentiation of dorsal telencephalic neuronsDEVELOPMENTAL DYNAMICS, Issue 8 2009Gudrun Viktorin Abstract emx3 is first expressed in prospective telencephalic cells at the anterior border of the zebrafish neural plate. Knockdown of Emx3 function by morpholino reduces the expression of markers specific to dorsal telencephalon, and impairs axon tract formation. Rescue of both early and late markers requires low-level expression of emx3 at the one- or two-somite stage. Higher emx3 expression levels cause dorsal telencephalic markers to expand ventrally, which points to a possible role of emx3 in specifying dorsal telencephalon and a potential new function for Wnt/beta-catenin pathway activation. In contrast to mice, where Emx2 plays a major role in dorsal telencephalic development, knockdown of zebrafish Emx2 apparently does not affect telencephalic development. Similarly, Emx1 knockdown has little effect. Previously, emx3 was thought to be fish-specific. However, we found all three emx orthologs in Xenopus tropicalis and opossum (Monodelphis domestica) genomes, indicating that emx3 was present in an ancestral tetrapod genome. Developmental Dynamics 238:1984,1998, 2009. © 2009 Wiley-Liss, Inc. [source] Survival of mammalian B104 cells following neurite transection at different locations depends on somal Ca2+ concentrationDEVELOPMENTAL NEUROBIOLOGY, Issue 2 2004Soonmoon Yoo Abstract We report that cell survival after neurite transection in a mammalian neuronal model (cultured B104 cells) critically depends on somal [Ca2+]i, a novel result that reconciles separate long-standing observations that somal survival decreases with more-proximal axonal transections and that increased somal Ca2+ is cytotoxic. Using fluorescence microscopy, we demonstrate that extracellular Ca2+ at the site of plasmalemmal transection is necessary to form a plasmalemmal barrier, and that other divalent ions (Ba2+, Mg2+) do not play a major role. We also show that extracellular Ca2+, rather than injury per se, initiates the formation of a plasmalemmal barrier and that a transient increase in somal [Ca2+]i significantly decreases the percentage of cells that survive neurite transection. Furthermore, we show that the increased somal [Ca2+]i and decreased cell survival following proximal transections are not due to less frequent or slower plasmalemmal sealing or Ca2+ entry through plasmalemmal Na+ and Ca2+ channels. Rather, the increased somal [Ca2+]i and lethality of proximal neurite injuries may be due to the decreased path length/increased diameter for Ca2+ entering the transection site to reach the soma. A ryanodine block of Ca2+ release from internal stores before transection has no effect on cell survival; however, a ryanodine- or thapsigargin-induced buildup of somal [Ca2+]i before transection markedly reduces cell survival, suggesting a minor involvement of Ca2+ -induced release from internal stores. Finally, we show that cell survival following proximal injuries can be enhanced by increasing intracellular Ca2+ buffering capacity with BAPTA to prevent the increase in somal [Ca2+]i. © 2004 Wiley Periodicals, Inc. J Neurobiol 60: 137,153, 2004 [source] Integrating glycaemic variability in the glycaemic disorders of type 2 diabetes: a move towards a unified glucose tetrad conceptDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 5 2009Louis Monnier Abstract The high incidence of atherosclerosis and cardiovascular disease (CVD) is the leading cause of morbidity and mortality among patients with diabetes. Evidence is accumulating that postprandial hyperglycaemia is an independent risk factor for diabetes-associated complications and mortality, and that worsening diabetes control is characterized by postprandial glucose (PPG) deterioration preceding an impairment in fasting glucose levels. Postprandial and general glucose fluctuations play a major role in activating oxidative stress, leading to the endothelial dysfunction, one of the mechanisms responsible for vascular complications. Therefore, the management of PPG is key for any strategy used in the monitoring and treatment of diabetes. We recommend that any strategy aimed at controlling the glycaemic disorders associated with type 2 diabetes, and limiting the risk of complications, should target the ,glucose tetrad', which comprises the following components: HbA1c, fasting and postprandial plasma glucose, and markers of glycaemic variability, such as the mean amplitude of glycaemic excursions (MAGE) index. This brings together, in a simple, unified concept, the conventional markers (HbA1c and fasting glucose) and the more recently recognized markers of glycaemic control (PPG excursions and acute glycaemic variability). Copyright © 2009 John Wiley & Sons, Ltd. [source] The mechanisms that underlie glucose sensing during hypoglycaemia in diabetesDIABETIC MEDICINE, Issue 5 2008R. McCrimmon Abstract Hypoglycaemia is a frequent and greatly feared side-effect of insulin therapy, and a major obstacle to achieving near-normal glucose control. This review will focus on the more recent developments in our understanding of the mechanisms that underlie the sensing of hypoglycaemia in both non-diabetic and diabetic individuals, and how this mechanism becomes impaired over time. The research focus of my own laboratory and many others is directed by three principal questions. Where does the body sense a falling glucose? How does the body detect a falling glucose? And why does this mechanism fail in Type 1 diabetes? Hypoglycaemia is sensed by specialized neurons found in the brain and periphery, and of these the ventromedial hypothalamus appears to play a major role. Neurons that react to fluctuations in glucose use mechanisms very similar to those that operate in pancreatic B- and A-cells, in particular in their use of glucokinase and the KATP channel as key steps through which the metabolic signal is translated into altered neuronal firing rates. During hypoglycaemia, glucose-inhibited (GI) neurons may be regulated by the activity of AMP-activated protein kinase. This sensing mechanism is disturbed by recurrent hypoglycaemia, such that counter-regulatory defence responses are triggered at a lower glucose level. Why this should occur is not yet known, but it may involve increased metabolism or fuel delivery to glucose-sensing neurons or alterations in the mechanisms that regulate the stress response. [source] Molecular mechanisms of insulin resistanceDIABETIC MEDICINE, Issue 6 2005S. Schinner Abstract Currently, we observe an epidemic expansion of diabetes mellitus. In subjects with Type 2 diabetes the resistance of fat, muscle and liver to insulin is the central pathophysiological event in the development of this disease. Genetic and environmental factors play a major role in this process, although the precise pathogenesis of insulin resistance and Type 2 diabetes is still largely unknown. However, recent studies have contributed to a deeper understanding of the molecular mechanisms underlying this process. In this review we therefore summarize the current developments in understanding the pathophysiological process of insulin resistance and Type 2 diabetes. Among the many molecules involved in the intracellular processing of the signal provided by insulin, insulin receptor substrate (IRS)-2, the protein kinase B (PKB)-, isoform and the forkhead transcription factor Foxo1a (FKHR) are of particular interest in this context as recent data have provided strong evidence that dysfunction of these proteins results in insulin resistance in-vivo. Furthermore, we have now increasing evidence that the adipose tissue not only produces free fatty acids that contribute to insulin resistance, but also acts as a relevant endocrine organ producing mediators (adipokines) that can modulate insulin signalling. The identification of the molecular pathophysiological mechanisms of insulin resistance and Type 2 diabetes is essential for the development of novel and more effective therapies to better treat our patients with insulin resistance and Type 2 diabetes. [source] Effects of diabetes on plasma nitrotyrosine levelsDIABETIC MEDICINE, Issue 6 2004X. L. Wang Abstract Background Oxidative stress plays a major role in disease processes such as atherosclerosis and diabetes. Peroxynitrite is a reaction product of nitric oxide (NO) and superoxide and a potent oxidant. The peroxynitrite-mediated tyrosine nitration, which forms nitrotyrosine (NT), is associated with several pathological conditions. Methods We measured plasma NT levels using the HPLC method in 40 Mexican Americans with diabetes, but not taking medications, and 40 age- and sex-matched euglycaemic controls. Results Plasma-free NT levels were not different between subjects with diabetes (11.0 ± 1.7 nmol/l, n = 40) and with non-diabetes (10.4 ± 1.5 nmol/l, n = 40). There was also no association with levels of fasting glucose (r = ,0.049, P = 0.663) or 2-h glucose (r = ,0.099, P = 0.390). However, females had significantly lower free NT level (7.6 ± 1.4 nmol/l, n = 40) than males (13.8 ± 1.7 nmol/l, n = 40, P = 0.005), which were not affected by age, smoking status, BMI and glucose levels. Conclusions In contrast to some earlier reports, our study shows that diabetes has no effect on plasma NT levels in Mexican Americans. We have also demonstrated lower free NT levels in females than males, which may partly explain the lower risk profile to vascular disease in women. [source] The Changing Emphasis of Disasters in Bangladesh NGOsDISASTERS, Issue 3 2001Nilufar Matin Bangladesh is one of the most disaster-prone countries in the world, affected by cyclones and floods, as well as chronic hazards such as arsenic poisoning. NGOs have played a major role in bringing concerns related to risk management on to the national agenda and promoting a shift of focus from mere relief response to disaster mitigation and preparedness. The government has, after earlier scepticism, now accepted NGOs as major partners in these tasks. Innovative approaches, such as the use of microfinance, have been applied; many of which are related to preserving the gains of development efforts as part of rehabilitation. NGOs have pressured for better co-ordination with government. Improved structures are now approved, but it is still too early to judge their impact. Despite progress, neither NGOs nor governmental agencies have clearly defined roles in the effort to link disaster management priorities. This will ensure that longer-term development efforts build on local capacities and reduce vulnerabilities. [source] Manometric study in Kearns,Sayre syndromeDISEASES OF THE ESOPHAGUS, Issue 1 2001K. H. Katsanos Although swallowing difficulties have been described in patients with Kearns,Sayre syndrome (KSS), the spectrum of manometric characteristics of dysphagia is not yet well known. Moreover, it is conceivable that a combination of various degrees of swallowing difficulties with different patterns in manometric studies exist, each playing a major role in the prognosis, natural history, and quality of life of KSS patients. An 18-year-old girl diagnosed at the age of 5 years with KSS (muscle biopsy) was admitted to our department with an upper respiratory tract infection and dysphagia. Clinical examination revealed growth retardation, external ophthalmoplegia, pigmentary retinopathy, impaired hearing, and ataxia. An electrocardiogram revealed cardiac conduction defects (long Q-T), and brain magnetic resonance imaging showed abnormalities in the cerebellar hemispheres. A manometric and motility study for dysphagia was conducted and the pharynx and upper esophageal sphincter (UES) resting pressures were similar to control group values, but the swallowing peak contraction pressure of the pharynx and the closing pressure of the UES were very low and could not promote effective peristaltic waves. Relaxation and coordination of the UES were not affected although pharyngeal and upper esophagus peristaltic waves proved to be very low and, consequently, were practically ineffective. The patient was started on treatment comprising a diet rich in potassium, magnesium, and calcium, and oral administration of vitamin D and co-enzyme Q10 100 mg daily; she was discharged 6 days later with apparent clinical improvement. [source] The role of fruit traits of bird-dispersed plants in invasiveness and weed risk assessmentDIVERSITY AND DISTRIBUTIONS, Issue 6 2009Carl R. Gosper Abstract Aim, Birds play a major role in the dispersal of seeds of many fleshy-fruited invasive plants. The fruits that birds choose to consume are influenced by fruit traits. However, little is known of how the traits of invasive plant fruits contribute to invasiveness or to their use by frugivores. We aim to gain a greater understanding of these relationships to improve invasive plant management. Location, South-east Queensland, Australia. Methods, We measure a variety of fruit morphology, pulp nutrient and phenology traits of a suite of bird-dispersed alien plants. Frugivore richness of these aliens was derived from the literature. Using regressions and multivariate methods, we investigate relationships between fruit traits, frugivore richness and invasiveness. Results, Plant invasiveness was negatively correlated to fruit size, and all highly invasive species had quite similar fruit morphology [smaller fruits, seeds of intermediate size and few (< 10) seeds per fruit]. Lower pulp water was the only pulp nutrient trait associated with invasiveness. There were strong positive relationships between the diversity of bird frugivores and plant invasiveness, and in the diversity of bird frugivores in the study region and another part of the plants' alien range. Main conclusions, Our results suggest that weed risk assessments (WRA) and predictions of invasive success for bird-dispersed plants can be improved. Scoring criteria for WRA regarding fruit size would need to be system-specific, depending on the fruit-processing capabilities of local frugivores. Frugivore richness could be quantified in the plant's natural range, its invasive range elsewhere, or predictions made based on functionally similar fruits. [source] The effect of practice on low-level auditory discrimination, phonological skills, and spelling in dyslexiaDYSLEXIA, Issue 2 2004Tina Schäffler Abstract Phonological awareness is believed to play a major role in the auditory contribution to spelling skills. The previous paper reports low-level auditory deficits in five different subdomains in 33,70% of the dyslexics. The first study of this paper reports the results of an attempt to improve low-level auditory skills by systematic daily practice of those tasks that had not been passed in previous diagnostic sessions. The data of 140 dyslexics indicate that the average number of unsolved tasks can be reduced from 3 of 5 to 1 of 5. The success rates have values of 70,80% for intensity and frequency discrimination and for gap detection, but reach only 36% for time-order judgement and 6% for side-order judgement. The second study reports that successful low-level auditory training transfers completely to language-related phonological skills and also to spelling with the largest profit in spelling errors due to poor auditory analysis. Control groups (waiting and placebo) did not exhibit significant improvements. It is concluded that low-level auditory deficits should be considered and improved by practice in order to give the dyslexics more phonological help when trying to transfer what they hear to spelling. Copyright © 2004 John Wiley & Sons, Ltd. [source] The linkage between velocity patterns and sediment entrainment in a forced-pool and riffle unitEARTH SURFACE PROCESSES AND LANDFORMS, Issue 2 2009D. M. Thompson Abstract A field-based project was initiated in order to characterize velocities and sediment entrainment in a forced-pool and riffle sequence. Three-dimensional velocities and turbulence intensities were measured with an acoustic Doppler velocimeter at 222 different points at three similar flows that averaged approximately 4·35 m3 s,1 within a large pool,riffle unit on North Saint Vrain Creek, Colorado. Sediment-sorting patterns were observed with the introduction of 500 tracer particles painted according to initial seeding location. Tracer particles moved sporadically during a 113 day period in response to the annual snowmelt peak flow, which reached a maximum level of 14·8 m3 s,1. Velocity data indicate high instantaneous velocities and turbulence levels in the centre of pools. Patterns of sediment deposition support the notion that stream competence is higher in the pool than the downstream riffle. Flow convergence around a large channel constriction appears to play a major role in multiple processes that include helical flow development and sediment routing, and backwater development with low velocities and turbulence levels above the constriction that may locally limit sediment supply. Jet flow, flow separation, vortex scour and turbulence generation enhance scour in the centre of pools. Ultimately, multiple processes appear to play some role in maintenance of this forced pool and the associated riffle. Copyright © 2008 John Wiley & Sons, Ltd. [source] Aeolian fetch distance and secondary airflow effects: the influence of micro-scale variables on meso-scale foredune developmentEARTH SURFACE PROCESSES AND LANDFORMS, Issue 7 2008Kevin Lynch Abstract Unsuccessful attempts to use process-scale models to predict long-term aeolian sediment transport patterns have long been a feature of aeolian research. It has been proposed that one approach to overcome these problems is to identify micro-scale variables that are important at longer timescales. This paper assesses the contribution of two system variables (secondary airflow patterns and fetch distance) to medium-term (months to years) dune development. The micro-scale importance of these variables had been established during previous work at the site (Magilligan Strand, Northern Ireland). Three methods were employed. First, sand drift potentials were calculated using 2 years of regional wind data and a sediment transport model. Second, wind data and large trench traps (2 m length × 1 m width × 1·5 m depth) were used to assess the actual sediment transport patterns over a 2-month period. Third, a remote-sensing technique for the identification of fetch distance, a saltation impact sensor (Safire) and wind data were utilized to gauge, qualitatively, sediment transport patterns over a 1-month period. Secondary airflow effects were found to play a major role in the sediment flux patterns at these timescales, with measured and predicted rates matching closely during the trench trap study. The results suggest that fetch distance is an unimportant variable at this site. Copyright © 2007 John Wiley & Sons, Ltd. [source] Runoff and soil loss under individual plants of a semi-arid Mediterranean shrubland: influence of plant morphology and rainfall intensityEARTH SURFACE PROCESSES AND LANDFORMS, Issue 5 2006E. Bochet Abstract The influence of plant morphology and rainfall intensity on soil loss and runoff was determined at the plant scale for three representative species of a semi-arid patchy shrubland vegetation of east Spain, representing contrasting canopy structures and plant phenologies (Rosmarinus officinalis, Anthyllis cytisoides and Stipa tenacissima). Twenty-seven microplots of less than 1 m2, each containing one single plant, were built to quantify runoff volume and sediment yield under the canopies of the three species. Runoff and rates of soil loss measured in these plots under natural rainfall conditions were compared with control microplots built in the bare inter-plant areas. Precipitation was automatic-ally recorded and rainfall intensity calculated over a two-year period. Results indicated that individual plants played a relevant role in interrill erosion control at the microscale. Compared with a bare soil surface, rates of soil loss and runoff reduction varied strongly depending on the species. Cumulative soil loss was reduced by 94·3, 88·0 and 30·2 per cent, and cumulative runoff volume was reduced by 66·4, 50·8 and 18·4 per cent under the Rosmarinus, Stipa and Anthyllis canopies, respectively, compared with a bare surface. Anthyllis was significantly less efficient than the two other species in reducing runoff volume under its canopy. Differences between species could only be identified above a rainfall intensity threshold of 20 mm h,1. The different plant morphologies and plant compon-ents explained the different erosive responses of the three species. Canopy cover played a major role in runoff and soil loss reduction. The presence of a second layer of protection at the soil surface (litter cover) was fundamental for erosion control during intense rainfall. Rainfall intensity and soil water status prior to rainfall strongly influenced runoff and soil loss rates. The possible use of these species in restoration programmes of degraded areas is discussed. Copyright © 2006 John Wiley & Sons, Ltd. [source] Predictability of river flow and suspended sediment transport in the Mississippi River basin: a non-linear deterministic approachEARTH SURFACE PROCESSES AND LANDFORMS, Issue 6 2005Bellie Sivakumar Abstract As the Mississippi River plays a major role in fulfilling various water demands in North America, accurate prediction of river flow and sediment transport in the basin is crucial for undertaking both short-term emergency measures and long-term management efforts. To this effect, the present study investigates the predictability of river flow and suspended sediment transport in the basin. As most of the existing approaches that link water discharge, suspended sediment concentration and suspended sediment load possess certain limitations (absence of consensus on linkages), this study employs an approach that presents predictions of a variable based on history of the variable alone. The approach, based on non-linear determinism, involves: (1) reconstruction of single-dimensional series in multi-dimensional phase-space for representing the underlying dynamics; and (2) use of the local approximation technique for prediction. For implementation, river flow and suspended sediment transport variables observed at the St. Louis (Missouri) station are studied. Specifically, daily water discharge, suspended sediment concentration and suspended sediment load data are analysed for their predictability and range, by making predictions from one day to ten days ahead. The results lead to the following conclusions: (1) extremely good one-day ahead predictions are possible for all the series; (2) prediction accuracy decreases with increasing lead time for all the series, but the decrease is much more significant for suspended sediment concentration and suspended sediment load; and (3) the number of mechanisms dominantly governing the dynamics is three for each of the series. Copyright © 2005 John Wiley & Sons, Ltd. [source] Role of Echocardiography in Assessing the Mechanism and Effect of Ramipril on Functional Mitral Regurgitation in Dilated CardiomyopathyECHOCARDIOGRAPHY, Issue 4 2005D.M. (Card), F.I.A.E., F.I.A.M.S., F.I.C.C., F.I.C.P., I.B. Vijayalakshmi M.D. The objectives of this article are to determine the possible mechanism of functional mitral regurgitation in patients with dilated cardiomyopathy (DCM) and to know the effect of ramipril on left ventricle (LV) and mitral regurgitation by ECHO. Several postulates are put forth for functional mitral regurgitation in DCM, and mitral annular dilatation is said to be the primary mechanism in the past, but the exact mechanism is not clear. Though angiotensin converting enzyme (ACE) inhibitors are known to remodel the LV, their beneficial effect in patients with DCM with functional mitral regurgitation is not known. Various cardiac dimensions and degree of mitral regurgitation were measured by echocardiography in 30 normal control group and in 30 patients with DCM of various etiologies except ischemic, before and after ramipril therapy. There was a significant difference in all parameters especially sphericity of left ventricle and position of papillary muscles (P < 0.0003) in DCM patients, but mitral valve annulus did not show significant change (P < 0.3) compared to control group. In 50% of the patients, the functional mitral regurgitation totally disappeared. In 30% of patients, it came down from grade II to I or became trivial. In 20% of patients, it remained unchanged. There was remarkable improvement in sphericity, LV dimension, volumes, and EF%, which increased from 31 ± 9.81 to 39.3 ± 8.3% (P < 0.0003). It is concluded that echocardiography clearly demonstrates the increased sphericity of LV in DCM. The lateral migration of papillary muscles possibly plays a major role in functional mitral regurgitation. Ramipril significantly reduces not only sphericity but also functional mitral regurgitation. [source] Ericaceous shrubs on abandoned block-cut peatlands: implications for soil water availability and Sphagnum restorationECOHYDROLOGY, Issue 4 2009Kegan K Farrick Abstract Following harvesting by manual block-cut methods and subsequent abandonment, Cacouna bog has undergone a natural vegetation succession, with ericaceous shrubs covering more than 90% of the surface. The abundance of shrubs plays a major role in the soil water flux and availability at the site, impacting Sphagnum regeneration. From June 1 to August 22, 2007, field measurements indicate that transpiration represented the largest water loss from the shrubs at 1·7 mm day,1, comprising 142 mm (42%) of rainfall, compared to 93 mm of evaporation (28%) from bare soil. The rainfall interception from the canopy (62 mm) and litter (15 mm) accounted for 23% of seasonal rainfall. Thus after transpiration and interception losses are accounted for, only 115 mm of the 334 mm of rain (34%) remained available for other processes (recharge/soil evaporation). In the field, the litter layer prevented 17 mm from being lost over the summer as it reduced evaporation by 18%. Laboratory experiments using intact soil monoliths with and without shrubs and litter indicate that at depths below 10 cm the water content from the shrub monoliths decreased 27% versus 20% in the bare peat monoliths because of root water uptake. As a management prescription, raising the water table within 20 cm of the surface would provide water to the most active root uptake zones, reducing the need for extraction from the upper 10 cm of the peat. At this level sufficient water can be supplied to the surface through capillary rise, providing adequate water for the reestablishment/survival of Sphagnum. Copyright © 2009 John Wiley & Sons, Ltd. [source] What happens during recessions, crunches and busts?ECONOMIC POLICY, Issue 60 2009Stijn Claessens Summary We provide a comprehensive empirical characterization of the linkages between key macroeconomic and financial variables around business and financial cycles, for 21 OECD countries over the period 1960,2007. In particular, we analyse the implications of 122 recessions, 113 (28) credit contraction (crunch) episodes, 114 (28) episodes of house price declines (busts), 245 (61) episodes of equity price declines (busts), and their various overlaps in these countries, over the sample period. Our results indicate that the interactions between macroeconomic and financial variables can play a major role in determining the severity and duration of a recession. Specifically, we find evidence that recessions associated with credit crunches and house price busts tend to be deeper and longer than other recessions. , Stijn Claessens, M. Ayhan Kose and Marco E. Terrones [source] THE QUALITY OF INSTITUTIONS AND FOREIGN DIRECT INVESTMENTECONOMICS & POLITICS, Issue 3 2007CHRISTIAN DAUDE Using bilateral foreign direct investment (FDI) stocks around the world, we explore the importance of a wide range of institutional variables as determinants of the location of FDI. While we find that better institutions have overall a positive and economically significant effect on FDI, some institutional aspects matter more than others do. Especially, the unpredictability of laws, regulations and policies, excessive regulatory burden, government instability and lack of commitment play a major role in deterring FDI. For example, the effect of a one standard deviation improvement in the regulatory quality of the host country increases FDI by a factor of around 2. These results are robust to different specifications, estimation methods, and institutional variables. We also present evidence on the significance of institutions as a determinant of FDI over time. [source] The role of electrophoresis in disease biomarker discoveryELECTROPHORESIS, Issue 12 2007Haleem J. Issaq Dr. Abstract There has been increased activity in the last few years in the search for disease markers using fractionation of complex biological fluids combined with MS. While electrophoretic and chromatographic separations have played a major role in this endeavor, this manuscript is limited to a review of electrophoretic methods that have been established for disease biomarker discovery. These methods include 2-DE, difference gel electrophoresis (DIGE), and CE. We define what constitutes a biomarker, identify the steps required for establishing a biomarker, and describe the parameters needed in the design of an ideal diagnostic test. The application, advantages, and limitations of CE, DIGE, and 2-DE in meeting the goal of discovering novel biomarkers is discussed in detail, along with a few selected examples that illustrate the search for biomarkers for cancer and neurological diseases. [source] High-throughput screening of kinase inhibitors by multiplex capillary electrophoresis with UV absorption detectionELECTROPHORESIS, Issue 1-2 2003Yan He Abstract Protein kinases play a major role in the transformation of cells and are often used as molecular targets for the new generation of anticancer drugs. We present a novel technique for high-throughput screening of inhibitors of protein kinases. The technique involves the use of multiplexed capillary electrophoresis (CE) for the rapid separation of the peptides, phosphopeptides, and various inhibitors. By means of UV detection, diversified peptides with native amino acid sequences and their phosphorylated counterparts can be directly analyzed without the need for radioactive or fluorescence labeling. The effects of different inhibitors and their IC50 value were determined using three different situations involving the use of a single purified kinase, two purified kinases, and crude cell extracts, respectively. The results suggest that multiplexed CE/UV may prove to be a straightforward and general approach for high-throughput screening of compound libraries to find potent and selective inhibitors of the various protein kinases. [source] Management of Fruit Flies (Diptera: Tephritidae) of the Most Perishable FruitsENTOMOLOGICAL RESEARCH, Issue 2 2005Muhammad Ahsan KHAN ABSTRACT We investigated to minimize the dependency on the use of chemicals and thus develop safe and environmental friendly control program for the most perishable fruits i.e., apple,,ber', guava and mango. Our findings on the composition of fruit fly species reveal that Bactrocera dorsalis was dominant on apple (33.96% existence), Corpomya incompleta on,ber'(51.91% existence) and Bactrocera zonata on guava (49.62% existence) and mango (74.66% existence). The correlation between population and infestation percentage was non-significant in apple orchards, whereas positive and highly significant in between population and infestation, as well as on the cumulative basis in,ber', guava and mango orchards during 1998-1999. Hoeing, baiting and methyl eugenol were statistically equal resulting about 77% decrease in infestation. The maximum control of 91.68% was observed where all four-control operations including Dipterex® were integrated together. Weather factors, when computed together, had maximum effect on population fluctuation and infestation with rainfall contributing the major role. For guava fruits, the months of August (14.06A individuals/trap/day) and September (13.81A individuals/trap/day) were important, resulting in maximum infestation percentage of 10.76 to 14.74%, respectively. [source] | |||||||||||||||||||||||||||||||||||||||||||