Relaxing the independent censoring assumption in the Cox proportional hazards model using multiple imputation.

The Cox proportional hazards model is frequently used in medical statistics. The standard methods for fitting this model rely on the assumption of independent censoring. Although this is sometimes plausible, we often wish to explore how robust our inferences are as this untestable assumption is relaxed. We describe how this can be carried out in a way that makes the assumptions accessible to all those involved in a research project. Estimation proceeds via multiple imputation, where censored failure times are imputed under user-specified departures from independent censoring. A novel aspect of our method is the use of bootstrapping to generate proper imputations from the Cox model. We illustrate our approach using data from an HIV-prevention trial and discuss how it can be readily adapted and applied in other settings

Multiple Paths Forward: Diversifying Mathematics as a Strategy for College Success (Executive Summary)

This executive summary outlines key findings from a report on how colleges are creating math pathways that are aligned with students' programs of study

Human embryo models: the importance of national policy and governance review

Integrated and non-integrated stem cell-based models of human embryos (SCB-EMs) are becoming widely adopted tools in biomedical research with distinct advantages over animal models for studying human development. Although SCB-EMs have tremendous benefits for research, they raise a number of social, ethical and legal questions which affect future research and widespread adoption in industry and clinical settings. The 2021 ISSCR guidelines for Stem Cell Research and Clinical Translation provide helpful guidance on many of these issues but do not have force in domestic law. Careful appraisal and development of national legal and ethical frameworks is crucial. Paving the way to better regulation provides an ethical and social foundation to continue using human embryo models and to fully realise their potential benefits for reproductive medicine

Assessing the Language of 2-year-olds: From Theory to Practice

Early screening for language problems is a priority given the importance of language for success in school and interpersonal relationships. The paucity of reliable behavioral instruments for this age group prompted the development of a new touchscreen language screener for 2-year-olds that relies on language comprehension. Developmental literature guided selection of age-appropriate markers of language disorder risk that are culturally and dialectally neutral and could be reliably assessed. Items extend beyond products of linguistic knowledge (vocabulary and syntax) and tap the process by which children learn language, also known as fast mapping. After piloting an extensive set of items (139), two phases of testing with over 500 children aged 2; 0–2; 11 were conducted to choose the final 40-item set. Rasch analysis was used to select the best fitting and least redundant items. Norms were created based on 270 children. Sufficient test-retest reliability, Cronbach\u27s alpha, and convergent validity with the MB-CDI and PPVT are reported. This quick behavioral measure of language capabilities could support research studies and facilitate the early detection of language problems

Decreased renal function and associated factors in cities, towns and rural areas of Tanzania: a community-based population survey.

OBJECTIVES: Data on renal dysfunction in sub-Saharan Africa, comparing urban and rural areas, have not yet been reported. Therefore, we aimed to determine the distribution of low estimated glomerular filtration rates (eGFRs) in urban and rural Tanzania, to describe factors associated with low eGFR and to quantify fractions attributable to common risk factors. METHODS: We conducted a community-based survey of 1095 randomly selected Tanzanian adults (≥18 years). A structured questionnaire and examinations were used to document sociodemographic characteristics, diet, physical activity, anthropomorphic measurements and blood pressure. Blood tests were performed for HIV infection, diabetes mellitus and creatinine. eGFR was calculated using two equations recommended for African adults. RESULTS: Serum creatinine was available for 1043 participants: 170 in Mwanza city, 326 in district towns and 547 in rural areas. Mean age was 35.5 years and 54% were females. The prevalence of eGFR < 60 ml/min/1.73 m(2) in these 3 strata was 2.3% (95% CI = 0.8-6.6%), 7.5% (4.7-11.8%) and 7.4% (5.1-10.6%), respectively. When age standardised to the WHO world population, prevalences were 3.8%, 10.1% and 8.1%. Factors associated with low eGFR included district town residence, older age, greater wealth, less physical activity and hypertension. Only 21% of cases with eGFR < 60 ml/min/1.73 m(2) were attributable to HIV, hypertension or diabetes. CONCLUSIONS: Decreased renal function is common in Tanzania, particularly in district towns, and unique risk factors for kidney disease may exist in this population. Population-specific strategies for prevention, early diagnosis and treatment of kidney disease are needed for Africa

Constructionism in Learning: Sustainable Life Cycle Engineering Project (CooL:SLiCE)

CooL:SLiCE, a distributed cyberlearning environment to facilitate consideration of engineering design impacts on the natural environment across product life cycles has been developed at XXX University, XXX University, and XXX University. CooL:SLiCE supports a constructionist line of inquiry within design practice by providing learners with technologies and other learning resources for experimentation and collaboration. By scaffolding these resources, CooL:SLiCE enables students to attain a deeper conceptual understanding of sustainable lifecycle product design. This poster will feature the elements of the CooL:SLiCE platform, pilot projects, and learning studies. The platform modules include 1) the Online Computer Aided Design (CAD) and Product Design Visualization Modules, 2) the Manufacturing Analysis Module, and 3) the Sustainable Product Architecture and Supplier Selection Module. CooL:SLiCE learning modules are developed for design customization activities with drones and multi-copters. The learning modules include drone design activities, handbooks and manuals, and tools for collaborative and individual reporting and assessment. Learners are also supplied with a library of 3D shapes, design data, and variant information (e.g., materials, dimensions, manufacturing processes, logistic costs, and potential suppliers) for drone design customization. Results of a preliminary study of potential learning contexts for CooL:SLiCE led to our focus on intercollegiate collaborative design projects for conveying the complexity of sustainable product design and lifecycle impacts to learners. Sustainable life cycle engineering designs developed through interacting with CooL:SLiCE will be compared with designs developed in traditional engineering learning contexts

Student Background and Implications for Design of Technology-Enhanced Instruction

Knowledge of students’ construction and technology background is an important input to the process of designing technology enhanced instruction. Current literature in student background is either not specific for the construction/civil engineering student population or lacks direct implications for pedagogical design. This paper presents a survey study that assesses students’ self-reported technology skills and attitude, learning preferences, and baseline construction knowledge. The survey is designed as a questionnaire with three sections: demographic and background information, technology attitude and exposure, and construction-related knowledge. From the 280 data points collected, it was found that today’s students are exposed to a wide range of technology applications. They had a positive attitude toward technology, were enthusiastic video-game players, and strongly preferred learning activities that involved interactions, whether these interactions were face-to-face or mediated by technology. These findings suggest that technology-assisted learning would excite and engage students. The paper also provides a discussion on specific pedagogical design implications of the findings and ways in which these could be incorporated in the design of technology-enhanced learning tools.Civil, Architectural, and Environmental Engineerin

An Evaluation Framework for Engineering Design Projects for Gender Bias, Domain Relatedness, and Ambiguity: Development

Engineering design learning is one of the key components for an engineering degree; thus engineering design projects are commonly included in engineering curricula to help students cultivate design thinking and creative problem-solving skills. However, an engineering design project is prone to the following issues if it is not appropriately provided to engineering students. First, gender bias can occur when the design project is perceived to be more skewed to one gender in comparison to the other. Second, domain bias can occur when the discipline of the design project is not related to the chosen major and interest areas of a student. Third, ambiguity can arise from the lack of clarity on design objectives and the scope. These issues can lead to diminished engagement and self-efficacy for engineering students. In order to tackle these issues, this study performs a preliminary work to build a framework that appropriately assesses engineering design projects. The evaluation framework is based on a measurement system that helps educators to evaluate the appropriateness of the design projects through designated questionnaires. The framework for design projects proposed in this study would help engineering educators to better prepare and revise their design projects, so that the engineering design projects can improve student engagement and learning performance