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Methods Analysis (methods + analysis)
Selected Abstracts4122: Exploring new strategies to record and analyse clinical electroretinogramsACTA OPHTHALMOLOGICA, Issue 2010P LACHAPELLE Purpose Investigate if the combination of time-frequency domain analysis and ERG dipole rotation reveals hidden features of the normal ERG that could be instrumental in the interpretation of nearly extinguished ERG responses. Methods Analyses were conducted on photopic ERGs (Photopic Hills: PH) obtained from normal subjects (n=75) and patients (n=65) affected with various retinopathies. A Discrete Wavelet Transform (DWT) was done on each ERGs and key descriptors (Holder exponent and wavelet coefficient maxima) were calculated. Dipole rotation was obtained by combining 11 gaze positions (0, 8, 16, 24, 32 and 40 degrees nasal or temporal to center) with 4 electrode locations [corneal (CE), lower lid (LL), external (EC) and internal canthi (IC)]. Results The Holder exponent follows a parabola, while some of the local wavelet maxima seem to follow a PH-like like distribution (b-wave and OPs) or a logistic growth function (a-wave). In still recordable pathological ERGs, the wavelet maxima matched that found in normal ERGs evoked at low stimulus intensities while in nearly extinguished ERGs (<10% of normal) the wavelet coefficients were significantly lower. Irrespective of the direction of gaze, there was little variation in DTL ERGs. EC ERGs were the only ones to reverse in polarity (seen 5 degrees nasal to fixation in nasal to temporal shift). Conclusion The parameters obtained with the DWT offers useful and reproducible tools to help identify subtle features of residual ERGs and therefore should allow for a more accurate quantification of low-voltage ERGs responses. Finally, our results suggest that varying the gaze and electrode positions would represent a valuable addition to the recording of clinical ERGs. Funded by NSERC. [source] Childhood body mass index (BMI), breastfeeding and risk of Type 1 diabetes: findings from a longitudinal national birth cohortDIABETIC MEDICINE, Issue 9 2008R. M. Viner Abstract Aims To perform a longitudinal analysis of the association between childhood body mass index (BMI) and later risk of Type 1 diabetes, controlling for socio-economic status, birthweight, height in early and late childhood, breastfeeding history and pubertal status. Methods Analysis of the 1970 British Birth Cohort, followed up at age 5, 10 and 30 years (n = 11 261). Data were available on birthweight, breastfeeding; height, weight, pubertal status, socio-economic status at age 10 years; self-report data on history of diabetes (type, age at onset) at age 30 years. Cox proportional hazards models were used to examine relations of childhood growth, socio-economic status and breastfeeding history to the incidence of Type 1 diabetes between 10 and 30 years of age. Results Sixty-one subjects (0.5%) reported Type 1 diabetes at 30 years of age; 47 (77%) reported onset , age 10 years. Higher BMI z -score at 10 years predicted higher risk of subsequent Type 1 diabetes (hazard ratio 1.8, 95% confidence interval 1.2 to 2.8, P = 0.01) when adjusted for birthweight, pubertal status, breastfeeding history and socio-economic status. Repeating the model for childhood obesity, the hazard ratio was 3.1 (1.0, 9.3; P = 0.05). Birthweight, breastfeeding, height growth and pubertal timing were not associated with incidence of Type 1 diabetes. Conclusions Higher BMI in childhood independently increased the risk of later Type 1 diabetes, supporting suggestions that obesity may provide a link between Type 1 and Type 2 diabetes. This supports observations of a rise in Type 1 diabetes prevalence. Reduction in childhood obesity may reduce the incidence of Type 1 as well as Type 2 diabetes. [source] European Union scientific production on alcohol and drug misuse (1976,2000)ADDICTION, Issue 8 2005Xavier Sánchez-Carbonell ABSTRACT Background Alcohol and drug misuse is a social and health phenomenon of great relevance in the European Union (EU). One indicator of scientific production in a given area is the analysis of publications included in bibliographic databases. Scientific production on alcohol and drug misuse was analysed in EU member countries, and comparisons were made between countries. Methods Analysis of articles on alcohol and drug misuse published during the period 1976,2000 by institutions based in a country of the EU, indexed by PsycINFO. Results A total of 4825 citations was retrieved. Great Britain published 38.6%, while Sweden, Germany and Spain accounted for a further 30%. The articles dealt with drug and alcohol usage (12.8%), substance abuse (53.5%) and drug and alcohol rehabilitation (34.5%). The articles were published in 13 different languages, more than three-quarters being in English. Spanish was the second language, and was followed by French, German, Dutch and Italian. The articles were published in 521 different journals, and 62 of these published more than 10 articles. The journals publishing most were Addiction, Alcohol and Alcoholism and Drug and Alcohol Dependence. Sixty-eight per cent of the articles were signed by more than one author, and the index of collaboration, between 1996 and 2000, was 3.24. Discussion and conclusions PsycINFO is useful for making comparisons between countries, because it includes the name and country of the institution. The number of publications in the EU on alcohol and drug misuse increased over the quarter-century analysed. The most used language was English, as it also is for PsycINFO as a whole, and a tendency towards its increased use was observed. Classification of the articles by subject by the Classification Code is too general, and makes it difficult to distinguish between the areas it proposes. Production tends to be concentrated in journals dealing specifically with drug dependence and psychiatry. The index of collaboration is similar to that found in other scientific areas. [source] Factors in the Pathogenesis of Tumors of the Sphenoid and Maxillary Sinuses: A Comparative Study,THE LARYNGOSCOPE, Issue S96 2000Anthony J. Reino MD Abstract Objectives/Hypothesis To explain the processes that lead to the development of tumors in the maxillary and sphenoid sinuses. Study Design A 32-year review of the world's literature on neoplasms of these two sinuses and a randomized case-controlled study comparing the normal mucosal architecture of the maxillary to the sphenoid sinus. Methods Analysis of a 32-year world literature review reporting series of cases of maxillary and sphenoid sinus tumors. Tumors were classified by histological type and separated into subgroups if an individual incidence rate was reported. Histomorphometry of normal maxillary and sphenoid sinus mucosa was performed in 14 randomly selected patients (10 sphenoid and 4 maxillary specimens). Specimens were fixed in 10% formalin, embedded in paraffin, and stained with periodic acid,Schiff (PAS) and hematoxylin. Histomorphometric analysis was performed with a Zeiss Axioscope light microscope (Carl Zeiss Inc., Thornwood, NY) mounted with a Hamamatsu (Hamamatsu Photonics, Tokyo, Japan) color-chilled 3 charge coupled device digital camera. The images were captured on a 17-inch Sony (Sony Corp., Tokyo, Japan) multiscan monitor and analyzed with a Samba 4000 Image Analysis Program (Samba Corp., Los Angeles, CA). Five random areas were selected from strips of epithelium removed from each sinus, and goblet and basal cell measurements were made at magnifications ×100 and ×400. Results The literature review revealed that the number and variety of tumors in the maxillary sinus are much greater than those in the sphenoid. The incidence of metastatic lesions to each sinus is approximately equal. No recognized pattern of spread from any particular organ system could be determined. On histomorphometric study there were no statistically significant differences between the sinuses in the concentration of goblet cells, basal cells, or seromucinous glands. Conclusions Factors involved in the pathogenesis of tumors of the maxillary and sphenoid sinuses include differences in nasal physiology, embryology, morphology, and topography. There are no significant histological differences in the epithelium and submucous glands between the two sinuses to explain the dissimilar formation of neoplasms. [source] Mixed methods research in school psychology: A mixed methods investigation of trends in the literaturePSYCHOLOGY IN THE SCHOOLS, Issue 4 2008Heather Powell This article illustrates the utility of mixed methods research (i.e., combining quantitative and qualitative techniques) to the field of school psychology. First, the use of mixed methods approaches in school psychology practice is discussed. Second, the mixed methods research process is described in terms of school psychology research. Third, the current state of affairs with respect to mixed methods designs in school psychology research is illustrated through a mixed methods analysis of the types of empirical studies published in the four leading school psychology journals between 2001 and 2005. Only 13.7% of these studies were classified as representing mixed methods research. We conclude that this relatively small proportion likely reflects the fact that only 3.5% of graduate-level school psychology programs appear to require that students enroll in one or more qualitative and/or mixed methods research courses, and only 19.3% appear to offer one or more qualitative courses as an elective. Finally, the utility of mixed methods research is illustrated by critiquing select monomethod (i.e., qualitative or quantitative) and mixed methods studies conducted on the increasingly important topic of bullying. We demonstrate how using mixed methods techniques results in richer data being collected, leading to a greater understanding of underlying phenomena. © 2008 Wiley Periodicals, Inc. [source] Phylogenetic analysis and species identification of popular shrimp species in southeast China using the first internally transcribed spacer of ribosomal DNAAQUACULTURE RESEARCH, Issue 11 2009Zhigang Wu Abstract The ribosomal DNA internally transcribed spacer 1 (ITS1) was investigated in the search for an appropriate genetic marker that was suitable for phylogenetic study and species identification of eight major exported shrimp species in southeast China. Using the selected primers, the amplified ITS1 sequences exhibited a high degree of length polymorphisms, ranging from 448 bp in Metapenaeopsis dalei to 1491 bp in Macrobrachium nipponense. Many microsatellite loci were found at the 5, end and in the middle region of ITS1, which seemed to be associated with intragenomic sequence variation among samples of the same species. This variation might obscure the phylogenetic relationship between some shrimp populations, but the separation of five Penaeus species was well supported. In combination with polymerase chain reaction-restriction fragment length polymerism methods analysis, ITS1 sequences from shrimp species belonging to different families and genera could also be easily discernable. The results suggested that ITS1 was highly variable among different shrimp groups and could be an appropriate marker for species identification and molecular systematic studies. [source] | ||||||||||