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Multiple Comparison Test (multiple + comparison_test)
Selected AbstractsAre you an invited speaker?JOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 6 2009A bibliometric analysis of elite groups for scholarly events in bioinformatics Participating in scholarly events (e.g., conferences, workshops, etc.) as an elite-group member such as an organizing committee chair or member, program committee chair or member, session chair, invited speaker, or award winner is beneficial to a researcher's career development. The objective of this study is to investigate whether elite-group membership for scholarly events is representative of scholars' prominence, and which elite group is the most prestigious. We collected data about 15 global (excluding regional) bioinformatics scholarly events held in 2007. We sampled (via stratified random sampling) participants from elite groups in each event. Then, bibliometric indicators (total citations and h index) of seven elite groups and a non-elite group, consisting of authors who submitted at least one paper to an event but were not included in any elite group, were observed using the Scopus Citation Tracker. The Kruskal,Wallis test was performed to examine the differences among the eight groups. Multiple comparison tests (Dwass, Steel, Critchlow,Fligner) were conducted as follow-up procedures. The experimental results reveal that scholars in an elite group have better performance in bibliometric indicators than do others. Among the elite groups, the invited speaker group has statistically significantly the best performance while the other elite-group types are not significantly distinguishable. From this analysis, we confirm that elite-group membership in scholarly events, at least in the field of bioinformatics, can be utilized as an alternative marker for a scholar's prominence, with invited speaker being the most important prominence indicator among the elite groups. [source] The effects of MRI signal intensity changes and clinical manifestations on prognosis after surgical intervention for cervical spondylotic myelopathyORTHOPAEDIC SURGERY, Issue 2 2009Ying-ze Zhang MD Objective:, To investigate whether the magnetic resonance (MR) T2 image signal intensity ratio and clinical manifestations can predict the prognosis in patients with cervical spondylotic myelopathy (CSM). Methods:, A total of 73 patients treated with anterior, posterior, or posterior-anterior combined surgery for compressive cervical myelopathy were enrolled retrospectively in this study. 1.5 T magnetic resonance imaging (MRI) was performed on all patients before surgery. T2-weighted images (T2WI) of sagittal signal intensity were obtained of the cervical spinal cord, and the regions of interest (ROI) were taken by 0.05 cm2. MR T2WI of sagittal normal cord signal at the C7-T1 disc level were also obtained, and the ROI were taken by 0.3 cm2. Signal value was measured by computer and the signal ratio between regions 0.05 cm2 and 0.3 cm2 calculated. Where no intramedullary high signal intensity was noted on MR T2WI, the ROI were taken by 0.05 cm2 of the region of most severe spinal cord compression. The 73 patients were divided into three groups by hierarchical clustering analysis with signal intensity ratio (group 1: low signal intensity ratio; group 2: middle signal intensity ratio; group 3: high signal intensity ratio). Statistical analyses were performed with SPSS 11.0. Results:, There were significant differences between the three groups according to the recovery rate (P < 0.001), age (P= 0.003), duration of disease (P= 0.001), Babinski sign (P < 0.001), pre- and postoperative Japanese Orthopaedic Association (JOA) score (P= 0.006). With increases in both signal intensity ratio grade and age, the recovery rate and pre- and postoperative JOA scores gradually decreased, and the incidence of Babinski sign increased. There was no significant difference in sex among the three groups (P= 0.387). Multiple comparison tests further supported the above-mentioned results. Conclusion:, Patients with light or no intramedullary signal changes on T2WI had a good surgical outcome. However, increase of signal intensity ratio and occurrence of the pyramidal sign were associated with a poor prognosis after surgery. [source] An In Vitro Investigation of a Comparison of Bond Strengths of Composite to Etched and Air-Abraded Human Enamel SurfacesJOURNAL OF PROSTHODONTICS, Issue 1 2006G.B. Gray BDS Purpose: The purposes of the study were to measure the tensile bond strength of composite resin to human enamel specimens that had been either etched or air-abraded, and to compare the quality of the marginal seal, through the assessment of microleakage, of composite resin to human enamel specimens that had been either etched or air-abraded. Materials and Methods: Thirty mandibular molar teeth were decoronated and sectioned mesio-distally to produce six groups, each containing ten specimens that were embedded in acrylic resin using a jig. In each of the four treatment groups, the specimen surfaces were treated by either abrasion with 27 or 50 ,m alumina at 4 mm or 20 mm distance, and a composite resin was bonded to the treated surfaces in a standardized manner. In the two control groups the specimens were treated with 15 seconds exposure to 36% phosphoric acid gel and then similarly treated before being stored in sterile water for 1 week. All specimens were then subjected to tensile bond strength testing at either 1 or 5 mm/min crosshead speed. For the microleakage study, the degree of dye penetration was measured 32 times for each treatment group, using a neutral methylene blue dye at the interface between composite and either 27 or 50 ,m air-abraded tooth structure or etched enamel surfaces. Results: The mean bond strength values recorded for Group 1 (phosphoric acid etch, 5 mm/min crosshead speed) was 25.4 MPa; Group 2 (phosphoric acid etch, 1 mm/min), 22.2 MPa; Group 3 (27 ,m alumina at 4 mm distance), 16.8 MPa; Group 4 (50 ,m alumina at 4 mm distance), 16.9 MPa; Group 5 (27 ,m alumina at 20 mm distance), 4.2 MPa; and for Group 6 (50 ,m alumina at 20 mm distance) 3.4 MPa. An analysis of variance (ANOVA) demonstrated significant differences among the groups, and a multiple comparison test (Tukey) demonstrated that conventionally etched specimens had a greater bond strength than air-abraded specimen groups. No significant difference in dye penetration could be demonstrated among the groups (p= 0.58). Conclusions: Composite resin applied to enamel surfaces prepared using an acid etch procedure exhibited higher bond strengths than those prepared with air abrasion technology. The abrasion particle size did not affect the bond strength produced, but the latter was adversely affected by the distance of the air abrasion nozzle from the enamel surface. The crosshead speed of the bond testing apparatus had no effect on the bond strengths recorded. The marginal seal of composite to prepared enamel was unaffected by the method of enamel preparation. [source] Pressure generated on a simulated oral analog by impression materials in custom trays of different designsJOURNAL OF PROSTHODONTICS, Issue 3 2002Radi Masri BDS Purpose To measure the pressure exerted by maxillary edentulous impressions composed of 3 commonly used impression materials using four different impression tray configurations. Materials and Methods The study was performed using an oral analog that simulated an edentulous maxillary arch. Three pressure transducers were imbedded in the oral analog, 1 in the mid-palate area and the other 2 in the right and left ridge (maxillary first premolar areas). Custom trays of 4 different configurations were fabricated. The 3 impression materials tested were irreversible hydrocolloid, light-body and medium-body vinyl polysiloxane, and polysulfide. A total of 128 impressions were made. The custom tray and the oral analog were mounted using a reline jig. A Satec universal testing machine was used to apply a constant pressure of 2 kg/cm2 over a period of 5 minutes on the loaded custom tray. The pressure was recorded every 10 seconds. Factorial analysis of variance and Tukey's multiple comparison test were used to analyze the results. Results A significant difference in the pressure produced using different impression materials was found (p,0.001). Irreversible hydrocolloid and medium-body vinyl polysiloxane produced a significantly higher pressure than light-body vinyl polysiloxane and polysulfide impression materials. The presence of holes and/or relief did not significantly alter the magnitude of pressure. Conclusions All impression materials produced pressure during maxillary edentulous impression making. Tray modification was not important in changing the amount of pressure produced. The impression materials used had more effect on the pressure produced during impression making on the simulated oral analog. [source] Protocol Optimization for Long-Term Liquid Storage of Goat Semen in a Chemically Defined ExtenderREPRODUCTION IN DOMESTIC ANIMALS, Issue 6 2009B-T Zhao Contents A specific problem in the preservation of goat semen has been the detrimental effect of seminal plasma on the viability of spermatozoa in extenders containing egg yolk or milk. The use of chemically defined extenders will have obvious advantages in liquid storage of buck semen. Our previous study showed that the self-made mZAP extender performed better than commercial extenders, and maintained a sperm motility of 34% for 9 days and a fertilizing potential for successful pregnancies for 7 days. The aim of this study was to extend the viability and fertilizing potential of liquid-stored goat spermatozoa by optimizing procedures for semen processing and storage in the mZAP extender. Semen samples collected from five goat bucks of the Lubei White and Boer breeds were diluted with the extender, cooled and stored at 5°C. Stored semen was evaluated for sperm viability parameters, every 48 h of storage. Data from three ejaculates of different bucks were analysed for each treatment. The percentage data were arcsine-transformed before being analysed with anova and Duncan's multiple comparison test. While cooling at the rate of 0.1,0.25°C/min did not affect sperm viability parameters, doing so at the rate of 0.6°C/min from 30 to 15°C reduced goat sperm motility and membrane integrity. Sperm motility and membrane integrity were significantly higher in semen coated with the extender containing 20% egg yolk than in non-coated semen. Sperm motility, membrane integrity and acrosomal intactness were significantly higher when coated semen was 21-fold diluted than when it was 11- or 51-fold diluted and when extender was renewed at 48-h intervals than when it was not renewed during storage. When goat semen coated with the egg yolk-containing extender was 21-fold diluted, cooled at the rate of 0.07,0.25°C/min, stored at 5°C and the extender renewed every 48 h, a sperm motility of 48% was maintained for 13 days, and an in vitro -fertilizing potential similar to that of fresh semen was maintained for 11 days. [source] Temperament assessments of lactating cows in three contexts and their applicability as management traitsANIMAL SCIENCE JOURNAL, Issue 6 2004Katsuji UETAKE ABSTRACT The applicability of three behavioral assessments of lactating cows as management traits was verified. Flight responses to an approaching human (flight starting and walking distances, and flight walking speed) at pasture, entrance order into the milking parlour and step-kick behavior to cup attachment were observed for 713 subject cows in six Australasian dairy farms. On all farms, cows were kept at pasture without any barn housing. Flight responses were measured once, and other assessments were recorded repeatedly for each subject cow. A principal component analysis was performed to verify whether these assessments appear to measure the same trait. A two-way anova and correlation analyses were then used to test whether obtained principal components were affected by farm, age and milking stage of cows. Australian and some Japanese herd management systems were compared for flight distance using a one-way anova and a multiple comparison test. Three behavioral assessments clustered in different principal components, indicating that these assessments did not appear to measure the same trait. Factor scores of four principal components were affected by farm (all, P < 0.01), and the scores of principal component 1, interpreted as fear of humans (r = ,0.16, P < 0.01), and component 2, interpreted as aversion to cup attachment (r = ,0.28, P < 0.01), were moderately correlated with age. These results emphasize the necessity of data standardization to reduce the non-genetic variation resulting from these two affectors. The flight distance at pasture of herds in Australia (6.06 ± 2.85 m) was significantly (P < 0.05) different from the flight distances measured in paddocks (1.50 ± 0.82 m) and free-stall barns (1.22 ± 1.09 m) in Japan. However, mean distances were not different between the Australian herds at pasture and the Japanese herds at pasture in tie-stall barns (3.96 ± 2.16 m) or in a free-stall barn (4.03 ± 1.79 m). This difference could be a result of the fact that only a single measurement was made, so that repeated measurement might improve the usefulness of flight distance as a management trait. In conclusion, it was verified that step-kick behavior to cup attachment and flight responses to human approach were, although they have some affectors, applicable as objective management traits in lactating cows. [source] Effects of different topical agents on enamel demineralization around orthodontic brackets: an in vivo and in vitro studyAUSTRALIAN DENTAL JOURNAL, Issue 3 2010T Uysal Abstract Background:, The aim of this study was to evaluate the in vivo and in vitro effects of a casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and fluoride containing topical agents in reducing enamel demineralization around orthodontic brackets, and to compare this with a control group. Methods:, Twenty-one patients and 60 extracted premolars were divided into three groups: two experimental and one control. Tooth Mousse® (CPP-ACP gel; GC-Corp, Tokyo, Japan) and Fluoridin N5® (Fluoride gel; Voco-GmbH, Cuxhaven, Germany) were applied to tooth surfaces around orthodontic brackets in the experimental groups. Teeth were extracted after 60 days to evaluate the in vivo effects of the testing materials. For the in vitro experiment, samples were cycled for 14 days through a daily procedure of demineralization. All teeth were sectioned and evaluated by superficial microhardness analysis. An indentation was made from two positions (occlusal-cervical) and one depth (10 ,m). Results:, Comparisons of occlusal and cervical microhardness scores for all specimens showed no statistically significant side differences. A multiple comparison test showed that the use of CPP-ACP and fluoride containing topical gels were more significantly efficient than the control group (p <0.001). No significant differences were detected between CPP-ACP and the fluoride groups against demineralization. Conclusions:,In vivo and in vitro evaluations indicated that CPP-ACP and fluoride containing agents successfully inhibited caries around orthodontic brackets. [source] Metabolism of Desipramine in Japanese Psychiatric Patients: The Impact of CYP2D6 Genotype on the Hydroxylation of DesipramineBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 6 2000Kazutaka Shimoda We investigated the impact of the genotype of CYP2D6 on the hydroxylation of desipramine in eighteen patients who were administered desipramine hydrochloride per os. Significantly higher plasma concentration of desipramine/daily dose of desipramine/body weight was observed in the subjects with two mutated alleles than in the subjects with either no mutated alleles or one mutated allele (two mutated alleles versus no mutated alleles=530.4±215.2 versus 118.1±63.9 ng/ml/mg/kg, t=5.68, P<0.001; two mutated alleles versus one mutated allele=530.4±215.2 versus 176.2±62.3 ng/ml/mg/kg, P<0.001; One-way analysis of variance followed by Bonferroni's multiple comparison test, respectively). Significantly higher ratio of desipramine/2-hydroxy-desipramine was observed in the subjects with two mutated alleles compared to subjects with no mutated alleles or the subjects with one mutated allele (two mutated alleles versus one mutated allele=4.39±0.36 versus 2.00±0.64, t=5.12, P<0.001; two mutated alleles versus no mutated alleles=4.39±0.36 versus 2.02±0.59, t=4.42, P<0.01). The genotyping of CYP2D6 only grossly predicts the steady state concentration of desipramine, mainly predicts the risk of getting very high plasma levels. Within each genotype there is marked interindividual variability. [source] Effects of endodontic instrument handle diameter on electromyographic activity of forearm and hand musclesINTERNATIONAL ENDODONTIC JOURNAL, Issue 2 2001T. Ozawa Abstract Aim To determine the influence of the handle diameter of endodontic instruments on forearm and hand muscle activity using electromyographic (EMG) recording. Methodology Size 45 K-type files were fitted with four different handle diameters; 3.5, 4.0, 5.0, and 6.0 mm. Seven dentists then attempted to negotiate to the working length acrylic resin root canals with each of the four handle sizes using a reaming motion. EMG activities were recorded from the flexor pollicis brevis muscle (f.p.b.), the flexor carpi radialis muscle (f.c.r.), and the brachioradialis muscle (b) with bipolar surface electrodes. The time taken to negotiate the canals, the area of integrated EMG that corresponded to the amount of EMG activity required during penetration and the maximum amplitude of EMG were measured using the EMG data. Results were analysed statistically using a one-way factorial anova test and multiple comparison tests. Results Reaming time and integrated EMG area of each muscle decreased with an increase in handle diameter. The most significant difference in time and area of integrated EMG was detected between handles of 6 mm and 3.5 mm diameter (time: P < 0.01, area of the f.p.b.: P < 0.01, area of the f.c.r. and b: P < 0.05), and between handles of 5 mm and 3.5 mm diameter (P < 0.05). Both 5 mm and 6 mm handles significantly decreased the maximum amplitude of EMG recorded from the f.p.b. compared with 3.5 mm handles (between 3.5 mm and 6 mm: P < 0.01, between 3.5 mm and 5 mm: P < 0.05). Conclusion The results indicate that handle diameter has an effect on reaming time as well as on muscle activity. As a consequence, handle diameter influenced operator performance during instrumentation. [source] Subgingival microbial profiles in chronic periodontitis patients from Chile, Colombia and SpainJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 2 2008David Herrera Abstract Aim: To investigate the subgingival microbiota of distinct periodontitis patient populations, in Chile, Colombia and Spain, using identical clinical and bacteriological methods. Material and Methods: In this multicentre study, 114 chronic periodontitis patients were selected. Patients were examined using an identical clinical protocol and pooled subgingival samples were obtained from each patient. Samples were processed in the three laboratories by means of culturing under identical clinical and microbiological protocols. Total anaerobic counts and frequency of detection and proportions of nine periodontal pathogens were calculated. Variables were analysed by means of anova, ,2, Kruskal,Wallis and Dunn's multiple comparison tests. Results: The Colombian population demonstrated greater severity of periodontitis, with significantly deeper mean probing pocket depth, and had a significantly lower percentage of current smokers. When comparing samples from the three patient populations, the total counts were significantly higher in the Colombian patients. The numbers of putative pathogens differed among groups. Tannerella forsythia was found less frequently in Chilean samples, while Parvimonas micra and enteric rods differed significantly among the three population groups. Conclusion: Significant differences among Chile, Colombia and Spain existed regarding the frequency and proportions of specific periodontal pathogens in the subgingival microbiota of periodontitis patients. [source] Effects of adhesive systems and luting agents on bonding of fiber posts to root canal dentinJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2006Francesca Monticelli Abstract The study evaluated the influence of different luting materials on the microtensile bond strength of glass fiber posts to root canal dentin. Thirty extracted maxillary premolars were endodontically treated, and the roots were prepared for post cementation using the FRC Postec system (Vivadent). Two luting materials (Multilink, Vivadent and Clearfil Photo Core, Kuraray) were used in combination with three adhesive: Multilink Primer (Vivadent), Clearfil Photo Bond, and Clearfil New Bond (Kuraray). A composite build-up was performed around the root to provide adequate gripping during testing. Specimens were cut to obtain beams with the post in the center and with the radicular dentin overlaid by the composite build-up on each side. Microtensile testing was performed with a universal testing machine at a cross-head speed of 0.5 mm/min. The failure mode was classified under a stereomicroscope and four representative beams of each group were selected for SEM analysis. Bond strength data that were analyzed with two-way ANOVA and Student-Newman-Keuls multiple comparisons tests revealed that adhesive systems, luting materials, and the interaction between these two factors significantly influenced the bond strength results (p < 0.01). Multilink applied with its own adhesive system obtained the best results, while the lowest bond strength was achieved with clearfil photo core in combination with multilink primer. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006 [source] | ||||||||||