Interparent agreement on the strengths and difficulties questionnaire : a Chinese study

This article reports on the first study to investigate interparent agreement when the Strengths and Difficulties Questionnaire (SDQ) is used to assess school-aged children. It is also the first study conducted in China on agreement between parents reporting on their child. Both parents of 380 girls and 320 boys completed the Strengths and Difficulties Questionnaire (Chinese version). Because reliabilities were poor, the Conduct Problems and Hyperactivity=Inattention subscales were merged to form an Externalizing Problems subscale, and the Peer Problems subscale as an independent variable was omitted from analyses. Consistent with past research, moderate to strong correlations were found between mother and father reports for emotional and behavioral problems, although interparent agreement was better for externalizing problems than internalizing problems for both girls and boys. Mothers reported significantly higher scores than fathers for prosocial behaviors for their sons. Findings suggest that, in general, one parent’s report will be similar to the other’s when the SDQ is used in the form adapted for this study. More work on the psychometric properties of the SDQ is needed in China.

Fracture strengths of Mg alloy AZ31B-H24 friction stir lap welds

The effects of selected friction stir lap welding parameters on fracture strength of Mg alloy AZ31B-H24 welds have been studied. Rotation speed has been found to affect significantly the flow related hook size formation. Furthermore, fracture strength decreased almost linearly with hook size. A small amount of softening was detected in fracture location that was outside the nugget zone and thus this softening may only adversely affect the fracture strength slightly. Finally, simulation results are presented to show the uneven stress distribution in a lap geometry which together with the relative brittleness of the stir material must be the cause to have significantly reduced the fracture strength.

Indoor location prediction using multiple wireless received signal strengths

This paper presents a framework for indoor location prediction system using multiple wireless signals available freely in public or office spaces. We first propose an abstract architectural design for the system, outlining its key components and their functionalities. Different from existing works, such as robot indoor localization which requires as precise localization as possible, our work focuses on a higher grain: location prediction. Such a problem has a great implication in context-aware systems such as indoor navigation or smart self-managed mobile devices (e.g., battery management). Central to these systems is an effective method to perform location prediction under different constraints such as dealing with multiple wireless sources, effects of human body heats or mobility of the users. To this end, the second part of this pa- per presents a comparative and comprehensive study on different choices for modeling signals strengths and prediction methods under different condition settings. The results show that with simple, but effective modeling method, almost perfect prediction accuracy can be achieved in the static environment, and up to 85% in the presence of human movements. Finally, adopting the proposed framework we outline a fully developed system, named Marauder, that support user interface interaction and real-time voice-enabled location prediction.

Normative data for the strengths and difficulties questionnaire for young children in Australia

AIM: The aim of this study was to report normative data for the parent-reported Strengths and Difficulties Questionnaire (SDQ) from a large population cohort of young children aged 4-6 years from Victoria, Australia, to establish age- and sex-specific cut-off values for future use, and to determine the scale reliability of the SDQ for children aged 4-6 years. METHODS: Parents of children (n = 53 372) entering their first year of school in Victoria in 2010 completed a survey via a 15-page School Entrant Health Questionnaire reporting on the physical and emotional well-being of their child (including the SDQ), use of child health and other support services, and a range of socio-demographic variables. Reliability was assessed and norms generated. Appropriate cut-off values for each SDQ scale and total difficulties scale were generated for each age group separately for each sex. RESULTS: The five scales of the SDQ and total difficulties scale generally had acceptable internal reliability. Mean SDQ scale scores differed for both sex and age, although only a narrow age range is examined in this study. Cut-off values were marginally higher for girls (lower for prosocial) and generally increased with age. CONCLUSIONS: This study has utilised a large Australian population sample of children to generate age- and sex-specific cut-off values that define SDQ scores as 'normal', 'borderline' or 'abnormal' for Australian children aged 4-6 years.

pH-cycling models for in vitro evaluation of the efficacy of fluoridated dentifrices for caries control: strengths and limitations

Despite a plethora of in situ studies and clinical trials evaluating the efficacy of fluoridated dentifrices on caries control, in vitro pH cycling models are still broadly used because they mimic the dynamics of mineral loss and gain involved in caries formation. This paper critically reviews the current literature on existing pH-cycling models for the in vitro evaluation of the efficacy of fluoridated dentifrices for caries control, focusing on their strengths and limitations. A search was undertaken in the MEDLINE electronic journal database using the keywords "pH-cycling", "demineralization", "remineralization", "in vitro", "fluoride", "dentifrice". The primary outcome was the decrease of demineralization or the increase of remineralization as measured by different methods (e. g.: transverse microradiography) or tooth fluoride uptake. Inclusion of studies, data extraction and quality assessment were undertaken independently and in duplicate by two members of the review team. Disagreements were solved by discussion and consensus or by a third party. One hundred and sixteen studies were included, of which 42 addressed specifically the comparison of dentifrices using different pH-cycling models. The other studies included meta-analysis or reviews, data about the effect of different fluoride sources on de-remineralization, different methods for analysis de-remineralization and chemical variables and characteristics of dental hard tissues that might have influence on de-remineralization processes. Generally, the studies presented ability to detect known results established by clinical trials, to demonstrate dose-related responses in the fluoride content of the dentifrices, and to provide repeatability and reproducibility between tests. In order to accomplish these features satisfactorily, it is mandatory to take into account the type of substrate and baseline artificial lesion, as well as the adequate response variables and statistical approaches to be used. This critical review of literature showed that the currently available pH-cycling models are appropriate to detect dose-response and pH-response of fluoride dentifrices, and to evaluate the impact of new active principles on the effect of fluoridated dentifrices, as well as their association with other anti-caries treatments.

THE EFFECT of IMMEDIATE DENTIN SEALING on THE MARGINAL ADAPTATION and BOND STRENGTHS of TOTAL-ETCH and SELF-ETCH ADHESIVES

Statement of problem. Sealing ability and bond strengths of total-etch and self-etch dentin adhesives used for immediate dentin sealing have not been assessed and established.Purpose. The purpose of this study was to determine the effectiveness of immediate dentin sealing (IDS) using total-etch or self-etch dentin adhesives on microleakage and microtensile bond strength.Material and methods. Twenty recently extracted molars were selected, and standard MOD inlay preparations were made with the gingival margins located below the cemento-enamel unction. The teeth were assigned to 4 experimental groups (n=5) according to the indirect composite restoration cementation technique used: (1) immediate dentin sealing with Adper Single Bond (TEBI); (2) conventional adhesive cementation technique using Adper Single Bond (TEAI); (3) immediate dentin sealing using Adper Prompt L-Pop (SEBI); or (4) conventional adhesive cementation technique using Adper Prompt L-Pop (SEAI). The restored teeth were thermal cycled 1,000 times between 5 degrees and 55 degrees C and then immersed in 50% ammoniacal silver nitrate. Three specimens per restoration were evaluated for microleakage, according to predefined scores, and submitted to Friedman's test (alpha-.05). The specimens were then sectioned to obtain 0.8 +/- 0.2-mm-thick sticks (with n ranging from 32 to 57 specimens) and submitted to microtensile bond strength (mu TBS) testing. The obtained data were submitted to 2-way ANOVA test (alpha=.05).Results. None of the experimental groups demonstrated complete elimination of marginal microleakage. There were significant differences in microleakage of the tested adhesives (P>.001). IDS microleakage scores were similar to those obtained using the conventional cementation technique (CCT) for both adhesives. The highest mean bond strengths were obtained with TEBI (51.1 MPa), whereas SEAI showed the lowest mean bond strengths (1.7 MPa). IDS resulted in significantly higher bond strengths than CCT (P<.001).Conclusions. Total-etch and self-etch adhesives have a significant effect on IDS. IDS resulted in high bond strengths for both adhesives; however, the microleakage was similar to that obtained with CCT (J Prosthet Dent 2009;102:1-9)

Bond strengths, degree of conversion of the cement and molecular structure of the adhesive-dentine joint in fibre post restorations

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Microtensile bond strengths and scanning electron microscopic evaluation of self-adhesive and self-etch resin cements to intact and etched enamel

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Determination of solubility product of mercurous acetate at various ionic strengths in aqueous medium

The conditionals (K-ps) and thermodynamics (K-ps(o)) solubility products of mercurous acetate have been determined, in aqueous solution, at 25 degrees C and ionic strength (I) comprised between 0.300 and 3.000 mol/L (NaClO4). The investigation was carried out potentiometrically by using a second class electrodes which responds to acetate ions. The values obtained for [pK(ps) (I)] were: 9.49+/-0.08 (0.000); 9.51+/-0.08 (0.300); 9.53+/-0.08 (0.500); 9.54+/-0.08 (0.700); 9.55+/-0.09 (0.900), 9.57+/-0.09 (1.200); 9.59+/-0.10(1.500); 9.61+/-0.10 (1.800); 9.63+/-0.10 (2.100); 9.65+/-0.11 (2.400); 9.67+/-0.11 (2.700) e 9.69+/-0.12 (3.000).