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A succession of interconnected environmental factors is believed to contribute substantially to the development of autism spectrum disorder (ASD). This exploratory study therefore aims to identify potential risk factors for ASD that are associated with pregnancy, birth and infant feeding. Demographic and health-related data on children aged 3–13 years (N = 4306) was collected through an online survey completed by biological mothers. A fitted logistic regression model identified advanced maternal age, prenatal bleeding, pre-eclampsia, perinatal pethidine usage, foetal distress before birth and male sex of child as associated with an increased risk of ASD, whereas longer gestational duration demonstrated a protective effect. These findings highlight potential risk factors and predictor interrelationships which may contribute to overall ASD risk. [ABSTRACT FROM AUTHOR]

The purpose of this study is to investigate the influence of fused deposition modeling (FDM) process parameters on the tribological behavior of PC-ABS built prototypes. Wear resistance of FDM manufactured parts in relation to the variation of FDM process parameters was analyzed and studied using definitive screening design and analysis of variance technique. The worn surfaces of some fabricated samples were also analyzed and investigated in this study by scanning electron microscope. Genetic algorithm was applied to optimize the wear resistance and to identify the exact effect of the input parameters. The results obtained from this study would have an impact on the FDM product performance in various industrial applications. This study demonstrates how the manufacturing parameters can be understood in FDM additive manufacturing technology. By implementing a similar approach, the optimum setting of process parameters, which gives the best tribological properties, can be determined whenever a new material is used for the FDM process. [ABSTRACT FROM AUTHOR]

Aim: Various reproductive health (RH) indicators have been formulated and used to measure RH services and status. Despite their widespread use, the measurement of these indicators has never been explored in a systematic manner. This study aimed to examine methods and methodologies in the measurement of common RH indicators in the Ethiopian context. Subjects and Methods: A mixed-method design, comprising in-depth expert interviews, the abstraction of information from relevant public documents and an analysis of peer-reviewed literature, was used. Information from these three sources was then organised and synthesised using a thematic approach. Results: Until now, routine health information system and demographic and health survey have been the primary sources for RH indicators in Ethiopia. A number of improvements have recently been made in data collection and aggregation methods; however, the focus has been more on the coverage of services than the quality of data. We noted that variations were observed in indicator definition between the two data sources and, as a consequence, in their estimates. It was found that many of the inherent limitations in the measurement of RH indicators could be addressed by making small modifications to the data sources and the reporting formats. Data quality concerns mainly occur at the point of data collection although there are also issues with data aggregation, dissemination and use. Conclusion: There is a gap in the measurement of the quality and continuity of RH services. Many of the limitations and data quality concerns in the measurement of RH indicators could be resolved with minimal improvements to the current health information system. [ABSTRACT FROM AUTHOR]

In fused deposition modeling (FDM) additive manufacturing process, it is often difficult to determine the actual levels of process parameters in order to achieve the best dynamic mechanical properties of FDM manufactured part. This is mainly due to the large number of FDM parameters and a high degree of interaction between the parameters affecting such properties. This requires a large number of experiments to be determined. This paper presents a study on the influence of six FDM process parameters (layer thickness, air gap, raster angle, build orientation, road width, and number of contours) on the dynamic mechanical properties of the FDM manufactured parts using the fraction factorial design. The most influential parameters were statistically obtained through the analysis of variance (ANOVA) technique, and the results indicate that the layer thickness, the air gap, and the number of contours have the largest impact on dynamic mechanical properties. The optimal parameters for maximum dynamic mechanical properties were found to be layer thickness of 0.3302 mm, air gap of 0.00 mm, raster angle of 0.0°, build orientation of 0.0°, road width of 0.4572 mm, and 10 contours. Finally, a confirmation experiment was performed using optimized levels of process parameters, which showed good fit with the estimated values. [ABSTRACT FROM AUTHOR]

In this paper, we use a maximal invariant likelihood (MIL) to construct two likelihood ratio (LR) tests in the context of a semi-linear regression model. The first involves testing for the inclusion of a non-linear regressor and the second involves testing a linear regressor against the alternative of a non-linear regressor. We report the results of a Monte Carlo experiment that compares tile size and power properties of the traditional LR tests with those of our proposed MIL based LR tests. Our simulation results show that in both cases, the MIL based tests have more accurate asymptotic critical values and better behaved (i.e., better centred) power curves than their classical counterparts. [ABSTRACT FROM AUTHOR]