Variational Foundations and Generalized Unified Theory of RVE-Based Multiscale Models

A unified variational theory is proposed for a general class of multiscale models based on the concept of Representative Volume Element. The entire theory lies on three fundamental principles: (1) kinematical admissibility, whereby the macro- and micro-scale kinematics are defined and linked in a physically meaningful way; (2) duality, through which the natures of the force- and stress-like quantities are uniquely identified as the duals (power-conjugates) of the adopted kinematical variables; and (3) the Principle of Multiscale Virtual Power, a generalization of the well-known Hill-Mandel Principle of Macrohomogeneity, from which equilibrium equations and homogenization relations for the force- and stress-like quantities are unequivocally obtained by straightforward variational arguments. The proposed theory provides a clear, logically-structured framework within which existing formulations can be rationally justified and new, more general multiscale models can be rigorously derived in well-defined steps. Its generality allows the treatment of problems involving phenomena as diverse as dynamics, higher order strain effects, material failure with kinematical discontinuities, fluid mechanics and coupled multi-physics. This is illustrated in a number of examples where a range of models is systematically derived by following the same steps. Due to the variational basis of the theory, the format in which derived models are presented is naturally well suited for discretization by finite element-based or related methods of numerical approximation. Numerical examples illustrate the use of resulting models, including a non-conventional failure-oriented model with discontinuous kinematics, in practical computations

Physician privacy concerns when disclosing patient data for public health purposes during a pandemic influenza outbreak

Background: Privacy concerns by providers have been a barrier to disclosing patient information for public health\ud purposes. This is the case even for mandated notifiable disease reporting. In the context of a pandemic it has been\ud argued that the public good should supersede an individual’s right to privacy. The precise nature of these provider\ud privacy concerns, and whether they are diluted in the context of a pandemic are not known. Our objective was to\ud understand the privacy barriers which could potentially influence family physicians’ reporting of patient-level\ud surveillance data to public health agencies during the Fall 2009 pandemic H1N1 influenza outbreak.\ud Methods: Thirty seven family doctors participated in a series of five focus groups between October 29-31 2009.\ud They also completed a survey about the data they were willing to disclose to public health units. Descriptive\ud statistics were used to summarize the amount of patient detail the participants were willing to disclose, factors that\ud would facilitate data disclosure, and the consensus on those factors. The analysis of the qualitative data was based\ud on grounded theory.\ud Results: The family doctors were reluctant to disclose patient data to public health units. This was due to concerns\ud about the extent to which public health agencies are dependable to protect health information (trusting beliefs),\ud and the possibility of loss due to disclosing health information (risk beliefs). We identified six specific actions that\ud public health units can take which would affect these beliefs, and potentially increase the willingness to disclose\ud patient information for public health purposes.\ud Conclusions: The uncertainty surrounding a pandemic of a new strain of influenza has not changed the privacy\ud concerns of physicians about disclosing patient data. It is important to address these concerns to ensure reliable\ud reporting during future outbreaks.University of Ottawa Open Access Author Fun

Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome

Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome

Doing things: Organizing for agency in mathematical learning

In the United States, school mathematics generally fails to help students see themselves as capable of impacting their world - a perspective Freire argues defines human agency. This analysis draws from a five-week Algebra intervention for middle school students (n = 46) designed to promote agency through collaborative mathematical activity. Typically, students identified as underperforming (as most in this intervention were), teachers revert to procedural, low-level instruction. In contrast, this intervention was designed around tasks of high cognitive demand that required visual or symbolic representation of algebraic concepts. Qualitative coding of student interviews (n = 46) confirm the design principles of authority, agency and collaboration were positively impactful for students. In particular, interviews evidence a changing perspective from math as boring to the possibility of math as comingling intellectual challenge and personal enjoyment. These results are traced to the design principles and in particular, the focus on organizing for agency

Doing things: Organizing for agency in mathematical learning

In the United States, school mathematics generally fails to help students see themselves as capable of impacting their world - a perspective Freire argues defines human agency. This analysis draws from a five-week Algebra intervention for middle school students (n = 46) designed to promote agency through collaborative mathematical activity. Typically, students identified as underperforming (as most in this intervention were), teachers revert to procedural, low-level instruction. In contrast, this intervention was designed around tasks of high cognitive demand that required visual or symbolic representation of algebraic concepts. Qualitative coding of student interviews (n = 46) confirm the design principles of authority, agency and collaboration were positively impactful for students. In particular, interviews evidence a changing perspective from math as boring to the possibility of math as comingling intellectual challenge and personal enjoyment. These results are traced to the design principles and in particular, the focus on organizing for agency

Integrating Power to Advance the Study of Connective and Productive Disciplinary Engagement in Mathematics and Science

Engle and Conant’s productive disciplinary engagement (PDE) framework has significantly advanced the study of learning in mathematics and science. This artilce revisits PDE through the lens of critical education research. Our analysis synthesizes two themes of power: epistemic diversity, and historicity and identity. We argue that these themes, when integrated into PDE, strengthen it as a tool for design and analysis of disciplinary learning in relation to power and personhood, and describe the broadened framework of connective and productive disciplinary engagement (CPDE). By comparing and contrasting the use of PDE and CPDE in relation to two cases of classroom learning—for science, Warren et al.’s metamorphosis and for mathematics, Godfrey and O’Connor’s measurement—we demonstrate how CPDE surfaces issues of history, power, and culture that may otherwise be overlooked by PDE alone. In particular, we analyze how CPDE makes visible unseen identities and generative resources of disciplinary knowing and doing among minoritized students. We discuss how the revised framework redresses epistemic injustice experienced by minoritized learners held to the narrow rubric of western epistemologies and compels close attention to the diversity of human activity in mathematics and science. Further, we elaborate how it provides a structure for teachers, teacher educators, and researchers to design and analyze learning environments as safeguarding the rightful presence of minoritized learners in STEM classrooms and beyond

Anticipating change: An exploratory analysis of teachers’ conceptions of engineering in an era of science education reform

While integrating engineering into science education is not new in the United States, technology and engineering have not been well emphasized in the preparation and professional development of science teachers. Recent science education reforms integrate science and engineering throughout K–12 education, making it imperative to explore the conceptions teachers hold of engineering as a discipline, and as an approach to teaching. This analysis draws on focus group interviews with practicing secondary teachers (n = 12) conducted during a professional development seminar. The goals of the seminar were to present engineering as a heterogeneity of practices and inquiries organized to solve human problems; and, to model design-build-test pedagogy as a new approach to teaching. Outcomes show teachers’ conceptions of engineering as a discipline are that it redefines failure as necessary for success, and that it can more directly link school learning to serving society. Teachers also anticipated that design-build-test pedagogy would disrupt procedural learning in science, and likely invert which students achieve and why. These outcomes are discussed in light of reform goals, particularly as regards issues of equity. Implications for science teacher educators are also discussed