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Methodological Differences (methodological + difference)
Selected AbstractsCaries prevalence in Belgian children: a reviewINTERNATIONAL JOURNAL OF PAEDIATRIC DENTISTRY, Issue 3 2001J. Vanobbergen A review of epidemiological surveys on dental caries prevalence, published between 1980 and 1999 in Belgian children, was compiled through a literature search. The number of studies performed in Belgium to date is limited. Methodological differences and confounding factors, especially socio-demographic influences, limit national comparisons of caries prevalence data. Although exact comparisons are difficult, data suggests a decline in caries prevalence in 5, 7 and 12 year-old Belgian schoolchildren in the last 20 years. In the primary dentition dmft values have decreased from 2·66 (1981) to 1·38 (1994) in 5-year-olds and from 4·1 (1983) to 2·24 (1996) in 7-year-olds. In 12-year-olds DMFT values in the permanent dentition have decreased from 3·9 (1983) to 1·93 (1994). WHO goals for the year 2000 appear to have been already reached in Flanders, with a recent estimate of 1·93 for DMFT in 12-year-olds and 56% of children being recorded as caries free at the age of 5. Continuing efforts are needed to screen the oral health of different age groups but standardised criteria and sampling procedures should be used if benefits are to be gained from national and international comparison. Data has often been limited to small selected areas and information representing the entire community of Flanders or Wallonia would be of particular value. [source] Effects of hippocampal lesions on the monkey's ability to learn large sets of object-place associations,HIPPOCAMPUS, Issue 4 2006Annabelle M. Belcher Abstract Earlier studies found that recognition memory for object-place associations was impaired in patients with relatively selective hippocampal damage (Vargha-Khadem et al., Science 1997; 277:376,380), but was unaffected after selective hippocampal lesions in monkeys (Malkova and Mishkin, J Neurosci 2003; 23:1956,1965). A potentially important methodological difference between the two studies is that the patients were required to remember a set of 20 object-place associations for several minutes, whereas the monkeys had to remember only two such associations at a time, and only for a few seconds. To approximate more closely the task given to the patients, we trained monkeys on several successive sets of 10 object-place pairs each, with each set requiring learning across days. Despite the increased associative memory demands, monkeys given hippocampal lesions were unimpaired relative to their unoperated controls, suggesting that differences other than set size and memory duration underlie the different outcomes in the human and animal studies. © 2005 Wiley-Liss, Inc. [source] 4351: Using the OHTS-EGPS risk calculator with OctopusTM visual field testingACTA OPHTHALMOLOGICA, Issue 2010AM STEVENS Purpose Assessing risk in ocular hypertensive (OHT)patients is not only of clinical importance for the patients with regard to their possible glaucomatous field damage but has major repercussions on their quality of life when making decisions about the use of eye drops for longer periods. Clinicians are not that good in estimating the risk hence the need for instruments to help them make a more evidence-based decision. The EGPS group states that a methodological difference " of using in a quarter of the patients another type of perimeter could explain the Hasard Ratio for the Pattern Standard Deviation (PSD) of 1.66 in EGPS and 1.27 in OHTS . Hence our interest to recalculate a conversion of the Octopus G1 program ( mostly used for glaucoma ) to the Humphrey 30-2 in a Group of ocular hypertensives conform the inclusions of the OHTS thus providing a way to use the calculator more accurately. Methods 50 OHT patients recruited using the OHTS criteria were tested both with the Humphrey 30-2 program and the Octopus G1 program. The Humphrey PSD values were plotted against the square root of the Loss of Variance (sLV) and a conversion formula was calculated Results Our data generated the following conversion formula: Y = 0.4X + 1.1 Conclusion Our conversion permits a proper use of the risk calculator in OHT patients. There has been an attempt to convert the values from Humphrey 30-2 to Octopus 32 by Monhart based on the results of a study by Langerhorst. Another approach could be based on the algorithm described by Zeyen using HFA 24-2 and G1 Octopus but proves difficult to use in daily practice. EGPS simply used "converted" indices by taking the square root of LV for PSD. Our formula is based on the same population as OHTS but yields different results [source] Four ways towards tropical herbivore megadiversityECOLOGY LETTERS, Issue 4 2008Thomas M. Lewinsohn Abstract Most multicellular species alive are tropical arthropods associated with plants. Hence, the host-specificity of these species, and their diversity at different scales, are keys to understanding the assembly structure of global biodiversity. We present a comprehensive scheme in which tropical herbivore megadiversity can be partitioned into the following components: (A) more host plant species per se, (B) more arthropod species per plant species, (C) higher host specificity of herbivores, or (D) higher species turnover (beta diversity) in the tropics than in the temperate zone. We scrutinize recent studies addressing each component and identify methodological differences among them. We find substantial support for the importance of component A, more tropical host species. A meta-analysis of published results reveals intermediate to high correlations between plant and herbivore diversity, accounting for up to 60% of the variation in insect species richness. Support for other factors is mixed, with studies too scarce and approaches too uneven to allow for quantitative summaries. More research on individual components is unlikely to resolve their relative contribution to overall herbivore diversity. Instead, we call for the adoption of more coherent methods that avoid pitfalls for larger-scale comparisons, for studies assessing different components together rather than singly, and for studies that investigate herbivore beta-diversity (component D) in a more comprehensive perspective. [source] Implementing the strategic environmental assessment (SEA) Directive in the South West of EnglandENVIRONMENTAL POLICY AND GOVERNANCE, Issue 3 2004Clare Brooke The South West of England is famous as being an area rich in environmental features and heritage. The tools available to local authorities and other organizations to protect this valued environment are being expanded to include strategic environmental assessment (SEA). SEA is being introduced under a European Community directive, which will be incorporated into UK law in 2004. The directive will require national, regional and local authorities to carry out environmental assessment on certain plans and programmes that they promote. To ensure that the effectiveness of SEA in the South West is maximized, the South West Regional Assembly is working with local authorities and regional partners to consider the implications of the directive, and help the region prepare for its implementation. The aim of the project is to more clearly define the potential for SEA within the South West, examine the barriers that organizations may face when implementing the directive and establish good practice within the region. Work has been carried out to examine specific requirements of the SEA Directive, including the baseline data requirements for undertaking SEAs, and methodological differences between SEA and sustainability appraisals. Existing practice was examined to consider how current planning processes can be adapted to fulfil the requirements of the directive. Case studies were also undertaken to examine the issues around implementing the directive for non-land-use plans, including transport, economic development, waste management, renewable energy and flood management. Copyright © 2004 John Wiley & Sons, Ltd and ERP Environment. [source] Valproate-induced thrombocytopenia: a prospective monotherapy studyEPILEPSIA, Issue 3 2008Wassim Nasreddine Summary Purpose: The frequency of valproate (VPA)-induced thrombocytopenia varied widely in previous studies, due to methodological differences. Our objective was to evaluate the relationship between trough VPA plasma levels and platelet counts and assess risk factors for the development of thrombocytopenia. Methods: Patients with refractory partial epilepsy were enrolled in this double-blind, multicenter, concentration,response trial that evaluated the efficacy and safety of high versus low trough plasma VPA concentrations following administration of divalproex sodium as monotherapy. Trough VPA concentrations and concomitant platelet counts were drawn at baseline and intermittently throughout the 24-week trial. Bivariate correlations and multivariate stepwise regression analysis were performed between platelet counts and multiple variables. A logistic regression analysis was done to determine the probability of developing thrombocytopenia at various VPA levels. Results: A total of 851 VPA levels and concomitant platelet counts were analyzed in 265 patients. Of these, 17.7% of patients experienced at least one episode of thrombocytopenia (platelet count , 100,000/,l) after exposure to divalproex sodium. A significant negative correlation was found between VPA levels and platelet counts. Women were significantly more likely to develop thrombocytopenia. The probability of developing thrombocytopenia substantially increased at trough VPA levels above 100 ,g/ml in women and above 130 ,g/ml in men. Discussion: Our data strongly support a causal relationship between rising plasma VPA levels and reduced platelet counts, with additional risk factors including female gender and lower baseline platelet counts. [source] Habitat use, abundance, and persistence of Neotropical migrant birds in a habitat matrix in northeast BelizeJOURNAL OF FIELD ORNITHOLOGY, Issue 3 2010Camila Gómez-Montes ABSTRACT To ensure adequate protection of nonbreeding habitats used by Neotropical migratory landbirds, we must first address questions about habitat use and quality. On the Yucatan peninsula, migrants use many habitats, several of which remain unstudied, and methodological differences preclude interhabitat comparisons based on studies to date. We used distance sampling along line transects in six habitats in northeast Belize to examine use of previously unstudied habitats (e.g., salt marsh) by Neotropical migrants and to permit comparison across habitats. We calculated unadjusted and adjusted (for detectability) density estimates for individual migrant species and for all species combined to generate hypotheses about habitat quality based on the assumption that density and quality are positively correlated. Adjusted density estimates for all migrants were highest in black mangrove habitat (1799 ± 110 ind/km2), intermediate in three forest types and milpa (range 598,802 ind/km2), and lowest in salt marsh (207 ± 32.3 ind/km2). By combining density estimates with habitat availability in our study region, we estimated that evergreen forest and black mangrove supported 70% and 9% of the region's migrant population, respectively. At the species level, five of the 10 most common species had habitat preferences (>50% detections in one habitat). Given the diversity of habitat preferences among species and apparent seasonal movements, our results indicate that Neotropical migrants in northeast Belize are dependent on a matrix of interconnected habitats. RESUMEN Para asegurar la protección adecuada del hábitat no- reproductivo utilizado por aves migratorias Neotropicales terrestres, debemos responder preguntas sobre el uso y la calidad del hábitat. En la península de Yucatán, lasaves migratorias utilizan muchos hábitats, varios de los cuales aún continúan sin ser estudiados. Además las diferencias metodológicas evitan hacer comparaciones inter-hábitat basadas en los estudios que se han hecho hasta ahora. Utilizamos unmuestreo a lo largo de transectos de distancia variable, en seis hábitats, algunos previamente no estudiados (ej. ciénagas salobres), en el noreste de Belize para examinar y comparar el uso por parte de las migratorias Neotropicales, Calculamos estimados de densidad, ajustados y no ajustados (para detectabilidad), para especies particulares de migratorias y para todas las especies combinadas para generar una hipótesis sobre la calidad del hábitat basándonos en la presunción que la densidad estaría positivamente correlacionada con la calidad del hábitat. Los estimados de densidad ajustados para todos los migratorios fueron más altos en mangle negro (1799 ± 100 ind/km2), intermedios en tres tipos de bosque y milpa rango 598,802 ind/km2) y menores en ciénagas salobres (207 ± 32.3 ind/km2). Combinando los estimados de densidad con la disponibilidad de hábitats en nuestra región de estudio, estimamos que el bosque siempreverde y el mangle negro sostienen el 70% y 9% de los migratorios en la región, respectivamente. A nivel de especies, cinco de las 10 especies más comunes tienen preferencias de hábitat (>50% de las detecciones en un hábitat). Dada la diversidad de preferencias de hábitat entre especies y el aparente movimiento estacional, nuestros resultados indican que las aves migratorias Neotropicales en el noreste de Belize dependen de una matriz de hábitats interconectados. [source] Subjective Response to Alcohol: A Critical Review of the LiteratureALCOHOLISM, Issue 3 2010Meghan E. Morean Background:, Subjective response to alcohol (SR), which reflects individual differences in sensitivity to the pharmacological effects of alcohol, may be an important endophenotype in understanding genetic influences on drinking behavior and alcohol use disorders (AUDs). SR predicts alcohol use and problems and has been found to differ by a range of established risk factors for the development of AUDs (e.g., family history of alcoholism). The exact pattern of SR associated with increased risk for alcohol problems, however, remains unclear. The Low Level of Response Model (LLR) suggests that high-risk individuals experience decreased sensitivity to the full range of alcohol effects, while the Differentiator Model (DM) asserts that high risks status is associated with increased sensitivity to alcohol's positive effects but decreased sensitivity to negative effects. Aims:, The current paper (1) reviews two prominent models of subjective response, (2) reviews extant laboratory-based research on subjective response, (3) highlights remaining gaps in our understanding and assessment of subjective response, and (4) encourages collaborative efforts to address these methodological and conceptual concerns. Methods:, This paper reviews studies which employed placebo-controlled and non-placebo-controlled alcohol challenge paradigms to assess a range of alcohol effects including impairment, stimulation, and sedation. Results:, The research literature provides at least partial support for both the LLR and DM models. High-risk individuals have been shown to have a reduced response to alcohol with respect to sedative or impairing effects, particularly on the descending limb of the blood alcohol curve (BAC). There is also evidence that ascending limb stimulant effects are more pronounced or operate differently for high-risk individuals. Discussion:, Despite commendable advances in SR research, important questions remain unanswered. Inconsistent results across studies may be attributable to a combination of an inadequate understanding of the underlying construct and methodological differences across studies (e.g., number and timing of assessments across the BAC, inclusion of a placebo condition). With respect to the underlying construct, existing measures fail to adequately distinguish between cognitive/behavioral impairment and sedation, aspects of which may be perceived positively (e.g., anxiolysis) due to their ability to act as negative reinforcers. Conclusions:, Addressing the concerns raised by the current review will be integral to making meaningful scientific progress in the field of subjective response. [source] Effectiveness of dentine bonding agents against cariogenic bacteria in vitro: a comparison of two methodsMOLECULAR ORAL MICROBIOLOGY, Issue 3 2003O. A. Schmidlin Data obtained from studies on the antimicrobial properties of bonding agents are the subject of controversy, probably because of methodological differences. This study compared two commonly used in vitro methods, the disc agar diffusion test and the well agar diffusion test. Agar plates were seeded with Streptococcus sobrinus, Lactobacillus gasseri, or Actinomyces naeslundii. For the well diffusion test, wells cut out of the agar were filled with the test material, and for the disc method, discs impregnated with the test material were applied to the agar; the discs and wells were both 9 mm in diameter. After incubation, measurements of the zones of inhibition showed little agreement between the two methods when bonding agents were tested; the mean differences (± sdiff) in the zones of inhibition between the methods were 0.7 ± 3.4 mm (P = 0.40, one sample t -test against zero), 4.9 ± 4.4 mm (P = 0.97), and 0.8 ± 4.3 mm (P = 0.47) for S. sobrinus, L. gasseri, and A. naeslundii, respectively. Mean differences were less contrasting when chlorhexidine and pure components were tested (P < 0.05 for S. sobrinus and L. gasseri). These results indicate the need for a gold standard method to evaluate the antimicrobial properties of bonding agents. [source] Immunopathogenic mechanisms in tourette syndrome: A critical review,,MOVEMENT DISORDERS, Issue 9 2009Davide Martino MD Abstract Tourette syndrome (TS) has a multifactorial etiology, in which genetic, environmental, immunological and hormonal factors interact to establish vulnerability. This review: (i) summarizes research exploring the exposure of TS patients to immune-activating environmental factors, and (ii) focuses on recent findings supporting a role of the innate and adaptive immune systems in the pathogenesis of TS and related disorders. A higher exposure prior to disease onset to group A ,-haemolytic streptococcal (GABHS) infections in children with tics and obsessive-compulsive (OC) symptoms has been documented, although their influence upon the course of disease remains uncertain. Increased activation of immune responses in TS is suggested by changes in gene expression profiles of peripheral immune cells, relative frequency of lymphocyte subpopulations, and synthesis of immune effector molecules. Increased activity of cell-mediated mechanisms is suggested by the increased expression of genes controlling natural killer and cytotoxic T cells, increased plasma levels of some pro-inflammatory cytokines which correlate with disease severity, and increased synthesis of antineuronal antibodies. Important methodological differences might account for some inconsistency among results of studies addressing autoantibodies in TS. Finally, a general predisposition to autoimmune responses in TS patients is indicated by the reduced frequency of regulatory T cells, which induce tolerance towards self-antigens. Although the pathogenic role of immune activation in TS has not been definitively proven, a pathophysiological model is proposed to explain the possible effect of immunity upon dopamine transmission regulation and the generation of tics. © 2009 Movement Disorder Society [source] The potential association between fruit intake and body weight , a reviewOBESITY REVIEWS, Issue 6 2009S. Alinia Summary Both national and international bodies recommend an increased intake of fruits and vegetables in order to decrease the risk of overweight and obesity. However, there is a rationale to investigate the separate role of fruits. The aim of this paper was to systematically review and analyse published human intervention, prospective observational and cross-sectional studies on fruit intake and body weight in adults. We identified three intervention, eight prospective observational and five cross-sectional studies that explored this relationship. Two of the intervention studies showed that fruit intake reduced body weight, five of the prospective observational studies showed that fruit consumption reduced the risk of developing overweight and obesity, and four of the cross-sectional studies found an inverse association between fruit intake and body weight. Important methodological differences and limitations in the studies make it difficult to compare results. However, the majority of the evidence points towards a possible inverse association between fruit intake and overweight. Future intervention and prospective observational studies examining the direct and independent role of fruit in body-weight management in free-living individuals are needed. Moreover, important determinants such as energy density, energy content, fruit and vegetable consumption, physical form of fruit and preparation methods need to be included in future studies. [source] Web-based Health Survey Systems in Outcome Assessment and Management of PainPAIN MEDICINE, Issue 2007Vinod K. Podichetty MD ABSTRACT Pain is a complex phenomenon lacking a well-defined paradigm for diagnosis and management across medical disciplines. This is due in part to inconsistencies in the assessment of pain as well as in the measurement of related social and psychological states. Efforts to evaluate and measure pain through objective tests have been hindered by challenges such as methodological differences in data acquisition, and the lack of common, universally accepted information systems. Physicians and hospital administrators have expressed mixed reactions to the costs that inevitably accompany advances in medical technology. Nonetheless, computer systems are currently being developed for use in the quantitative assessment and management of pain, which can advance our understanding of the public health impact of pain, improve the care individual patients receive, and educate providers. The description of an interdisciplinary, integrated, health survey system illustrates the approach and highlights the advantages of using information technology in pain evaluation and management. [source] Human cranial anatomy and the differential preservation of population history and climate signaturesTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 12 2006Katerina Harvati Abstract Cranial morphology is widely used to reconstruct evolutionary relationships, but its reliability in reflecting phylogeny and population history has been questioned. Some cranial regions, particularly the face and neurocranium, are believed to be influenced by the environment and prone to convergence. Others, such as the temporal bone, are thought to reflect more accurately phylogenetic relationships. Direct testing of these hypotheses was not possible until the advent of large genetic data sets. The few relevant studies in human populations have had intriguing but possibly conflicting results, probably partly due to methodological differences and to the small numbers of populations used. Here we use three-dimensional (3D) geometric morphometrics methods to test explicitly the ability of cranial shape, size, and relative position/orientation of cranial regions to track population history and climate. Morphological distances among 13 recent human populations were calculated from four 3D landmark data sets, respectively reflecting facial, neurocranial, and temporal bone shape; shape and relative position; overall cranial shape; and centroid sizes. These distances were compared to neutral genetic and climatic distances among the same, or closely matched, populations. Results indicate that neurocranial and temporal bone shape track neutral genetic distances, while facial shape reflects climate; centroid size shows a weak association with climatic variables; and relative position/orientation of cranial regions does not appear correlated with any of these factors. Because different cranial regions preserve population history and climate signatures differentially, caution is suggested when using cranial anatomy for phylogenetic reconstruction. Anat Rec Part A, 2006. © 2006 Wiley-Liss, Inc. [source] | |||||||||||||