Conversion of Digital Circuits Labs

The engineering technology department at ETSU currently lacks a modern method to teach digital circuits. The aim of this thesis is to convert our current digital circuits labs to equivalent labs suited to run on the Basys 3. The Basys has several advantages over the aging NI Elvis boards (and now just breadboards) currently in use. The first advantage is that the Basys gives students a taste of FPGA programming without being overwhelmingly; like the systems currently in place for the digital signal processing class. The Basys is also a more modern system; our current integrated circuit and breadboard system is from the 70’s and has little to do with the modern world of electronics. There are several major difficulties with moving towards the Basys 3. It requires several tweaks to the current computer security setting of the lab computers. The other issue to be solved is that very few people in the department have even an inkling of how to program in VHDL and most of them are outgoing students. This lack of skills could be a threat to the class but I have included an appendix and a few recommendations for books on the subject to ensure that system development can continue. The other objective of this project was to see if there were ways to incorporate new educational techniques into the engineering technology curriculum. While there have been no actual tests on students, the groundwork has been laid to use some new ideas in the classroom. All of these new systems are designed to get students to think about how devices actually work and develop models to help them fully understand what is being taught

Macroscopic Equations of Motion for Two Phase Flow in Porous Media

The established macroscopic equations of motion for two phase immiscible displacement in porous media are known to be physically incomplete because they do not contain the surface tension and surface areas governing capillary phenomena. Therefore a more general system of macroscopic equations is derived here which incorporates the spatiotemporal variation of interfacial energies. These equations are based on the theory of mixtures in macroscopic continuum mechanics. They include wetting phenomena through surface tensions instead of the traditional use of capillary pressure functions. Relative permeabilities can be identified in this approach which exhibit a complex dependence on the state variables. A capillary pressure function can be identified in equilibrium which shows the qualitative saturation dependence known from experiment. In addition the new equations allow to describe the spatiotemporal changes of residual saturations during immiscible displacement.Comment: 15 pages, Phys. Rev. E (1998), in prin

A research-informed dialogic-teaching approach to early secondary school mathematics and science: the pedagogical design and field trial of the epiSTEMe intervention

The $\textit{Effecting Principled Improvement in STEM Education [epiSTEMe]}$ project undertook pedagogical research aimed at improving pupil engagement and learning in early secondary school physical science and mathematics. Using principles identified as effective in the research literature and drawing on a range of existing pedagogical resources, the project designed and trialled a classroom intervention, with associated professional development, in a form intended to be suited to implementation at scale. The most distinctive feature of the $\textit{epiSTEMe}$ pedagogical approach is its inclusion of a component of dialogic teaching. Aimed at the first year of secondary education in English schools (covering ages 11–12), the $\textit{epiSTEMe}$ intervention consists of a short introductory module designed to prepare classes for this dialogic teaching component, and topic modules which employ the $\textit{epiSTEMe}$ pedagogical approach to cover two curricular topics in each of science and mathematics. A field trial was conducted over the 2010/2011 school year in 25 volunteer schools, randomly assigned to intervention and control groups. Within the intervention group, observation of lessons indicated that the level of dialogic teaching was higher for one of the topic modules than others. Evaluation focused on the effectiveness of the topic modules, each trialled in more than 10 classes containing a total of over 300 pupils, and compared with a group of similar composition. Overall, at this first implementation, learning gains under the $\textit{epiSTEMe}$ intervention were no greater, although for individual topic modules the effects ranged from small negative to small positive. No difference was found between intervention and control groups either in the opinion of pupils about their classroom experience or in changes in their attitude towards subjects.Thanks are due to the Economic and Social Research Council which provided funding for the epiSTEMe project (RES-179-25-0003), to the teachers who generously volunteered to review, pilot and trial versions of the modules, to Christine Howe for her contribution to design and analysis, and to Andy Tolmie and Anna Vignoles for statistical advice.This is the final version of the article. It first appeared from Taylor & Francis via https://doi.org/10.1080/02671522.2015.112964

Limnología inicial de Laguna Pozo Verde, Costa Rica: Batimetría, agua, sedimentos y diatomeas

Introducción : Costa Rica tiene cientos de lagos, muchos de los cuales nunca han sido estudiados científicamente.  Objetivo: Conocer limnológia  de la Laguna Pozo Verde en el Parque Nacional Juan Castro Blanco, Costa Rica (~1935 m de elevación), para proporcionar datos de referencia para estudiar cambios futuros. Métodos: Medimos la profundidad y temperatura del agua y la profundidad de Secchi; sedimentos superficiales analizados; y examinó mapas e imágenes de satélite. Resultados: Aunque algunos la describen como formada por procesos volcánicos, la Laguna Pozo Verde probablemente se formó en un deslizamiento de tierra, que ocurre con frecuencia en esta zona lluviosa en la empinada ladera sur del inactivo volcán Porvenir. Nuestros sondeos mostraron una profundidad máxima de 9,25 m cerca del centro del lago. El agua era moderadamente transparente (profundidad de Secchi 2,6 m), con pH circunneutro y temperaturas de 15,9 a 18,1 °C, con estratificación débil a 0,5 m. Los sedimentos superficiales contenían 27% de materia orgánica y tenían relaciones C/N y valores de isótopos de carbono estables consistentes con algas lacustres y plantas C 3 ; Surirella angusta compuso más del 90% de las diatomeas. Conclusión: La laguna es significativamente más omera de lo informado y los sedimentos superficiales albergar una combinación de diatomeas única entre los 88 lagos examinados en Costa Rica.Introducción: Costa Rica tiene cientos de lagos, muchos nunca estudiados científicamente. Objetivo: Conocer la limnología de Laguna Pozo Verde en el Parque Nacional Juan Castro Blanco, Costa Rica (~1935m de elevación), como referencia para estudiar futuros cambios. Métodos: Medimos la profundidad y temperatura del agua y la profundidad de Secchi; analizamos sedimentos superficiales; y examinamos mapas e imágenes satelitales. Resultados: Aunque algunos la describen como formada por procesos volcánicos, es probable que Laguna Pozo Verde se haya formado en un deslizamiento de tierra, algo común en esta zona lluviosa de la empinada ladera sur del Volcán Porvenir (inactivo). Hallamos una profundidad máxima de 9,25m cerca del centro. El agua era moderadamente transparente (profundidad de Secchi 2,6m), con un pH cercano a neutro y temperaturas de 15,9-18,1°C, y una débil estratificación a 0,5m. Los sedimentos superficiales contenían un 27% de materia orgánica y tenían cocientes C/N y valores de isótopos de carbono estables, coherentes con algas lacustres y plantas C 3 ; más del 90% de las diatomeas eran Surirella angusta . Conclusión: La laguna es significativamente más somera de lo informado y los sedimentos superficiales albergan una combinación de diatomeas única entre los 88 lagos examinados en Costa Rica

Perceived psychosocial stress and glucose intolerance among pregnant Hispanic women

Aim—Prior literature suggests a positive association between psychosocial stress and the risk of diabetes in non-pregnant populations, but studies during pregnancy are sparse. We evaluated the relationship between stress and glucose intolerance among 1115 Hispanic (predominantly Puerto Rican) prenatal care patients in Proyecto Buena Salud, a prospective cohort study in Western Massachusetts (2006–2011). Methods—Cohen’s Perceived Stress Scale (PSS-14) was administered in early (mean = 12.3 weeks gestation; range 4.1–18 weeks) and mid-(mean = 21.3 weeks gestation; range 18.1–26 weeks) pregnancy. Participants were classified as having a pregnancy complicated by gestational diabetes mellitus, impaired glucose tolerance, and abnormal glucose tolerance, based on the degree of abnormality on glucose tolerance testing between 24 and 28 weeks of gestation. Results—The prevalence of gestational diabetes mellitus, impaired glucose tolerance, and abnormal glucose tolerance was 4.1%, 7.2%, and 14.5%, respectively. Absolute levels of early or mid-pregnancy stress were not significantly associated with glucose intolerance. However, participants with an increase in stress from early to mid-pregnancy had a 2.6-fold increased odds of gestational diabetes mellitus (95% confidence intervals: 1.0–6.9) as compared to those with no change or a decrease in stress after adjusting for age and pre-pregnancy body mass index. In addition, every one-point increase in stress scores was associated with a 5.5 mg/dL increase in screening glucose level (β = 5.5; standard deviation = 2.8; P = 0.05), after adjusting for the same variables. Conclusion—In this population of predominantly Puerto Rican women, stress patterns during pregnancy may influence the risk of glucose intolerance

Diffusion Tensor Imaging Detects Early Cerebral Cortex Abnormalities in Neuronal Architecture Induced by Bilateral Neonatal Enucleation: An Experimental Model in the Ferret

Diffusion tensor imaging (DTI) is a technique that non-invasively provides quantitative measures of water translational diffusion, including fractional anisotropy (FA), that are sensitive to the shape and orientation of cellular elements, such as axons, dendrites and cell somas. For several neurodevelopmental disorders, histopathological investigations have identified abnormalities in the architecture of pyramidal neurons at early stages of cerebral cortex development. To assess the potential capability of DTI to detect neuromorphological abnormalities within the developing cerebral cortex, we compare changes in cortical FA with changes in neuronal architecture and connectivity induced by bilateral enucleation at postnatal day 7 (BEP7) in ferrets. We show here that the visual callosal pattern in BEP7 ferrets is more irregular and occupies a significantly greater cortical area compared to controls at adulthood. To determine whether development of the cerebral cortex is altered in BEP7 ferrets in a manner detectable by DTI, cortical FA was compared in control and BEP7 animals on postnatal day 31. Visual cortex, but not rostrally adjacent non-visual cortex, exhibits higher FA than control animals, consistent with BEP7 animals possessing axonal and dendritic arbors of reduced complexity than age-matched controls. Subsequent to DTI, Golgi-staining and analysis methods were used to identify regions, restricted to visual areas, in which the orientation distribution of neuronal processes is significantly more concentrated than in control ferrets. Together, these findings suggest that DTI can be of utility for detecting abnormalities associated with neurodevelopmental disorders at early stages of cerebral cortical development, and that the neonatally enucleated ferret is a useful animal model system for systematically assessing the potential of this new diagnostic strategy

Secondary students' values and perceptions of science-related careers: responses to vignette-based scenarios

There has been concern about the attractiveness of science-based careers to many adolescent learners, and it has been suggested that school science may not always recognise or engage personal values that are important to young people in making life choices. The present study discusses interview comments made by upper secondary level students in England when 15 young people were asked to give their personal responses to brief vignettes describing scientific careers. Using an interview-about-scenarios approach, the students were asked about whether they would feel comfortable working in the scientific careers represented. The career areas were purposefully selected because they might be considered to potentially raise issues in relation to personal values or commitments that some students might hold. A range of student perceptions relating to the mooted careers were elicited (positive, negative and indifferent), but all of the participants raised issues that impacted on the acceptability or attractiveness of at least one of the mooted scientific careers, in terms of aspects of their own personal beliefs and values systems. It is recommended that teachers and career advisors should be aware of the range of value-related considerations that influence student views of science-related careers and should consider exploring aspects of science-based careers that link to values commonly shared by young people. This exploratory study also offers indications for directions for further research exploring how learners' value systems impact upon their perceptions of science and scientific work

Analytical and numerical analyses of the micromechanics of soft fibrous connective tissues

State of the art research and treatment of biological tissues require accurate and efficient methods for describing their mechanical properties. Indeed, micromechanics motivated approaches provide a systematic method for elevating relevant data from the microscopic level to the macroscopic one. In this work the mechanical responses of hyperelastic tissues with one and two families of collagen fibers are analyzed by application of a new variational estimate accounting for their histology and the behaviors of their constituents. The resulting, close form expressions, are used to determine the overall response of the wall of a healthy human coronary artery. To demonstrate the accuracy of the proposed method these predictions are compared with corresponding 3-D finite element simulations of a periodic unit cell of the tissue with two families of fibers. Throughout, the analytical predictions for the highly nonlinear and anisotropic tissue are in agreement with the numerical simulations

Learning to Teach About Ideas and Evidence in Science : The Student Teacher as Change Agent

A collaborative curriculum development project was set up to address the lack of good examples of teaching about ideas and evidence and the nature of science encountered by student teachers training to teach in the age range 11-16 in schools in England. Student and teacher-mentor pairs devised, taught and evaluated novel lessons and approaches. The project design required increasing levels of critique through cycles of teaching, evaluation and revision of lessons. Data were gathered from interviews and students' reports to assess the impact of the project on student teachers and to what extent any influences survived when they gained their first teaching posts. A significant outcome was the perception of teaching shifting from the delivery of standard lessons in prescribed ways to endeavours demanding creativity and decision-making. Although school-based factors limited newly qualified teachers' chances to use new lessons and approaches and therefore act as change-agents in schools, the ability to critique curriculum materials and the recognition of the need to create space for professional dialogue were durable gains

Confirmation bias in the utilization of others' opinion strength

Humans tend to discount information that undermines past choices and judgments. This confirmation bias has significant impact on domains ranging from politics to science and education. Little is known about the mechanisms underlying this fundamental characteristic of belief formation. Here we report a mechanism underlying the confirmation bias. Specifically, we provide evidence for a failure to use the strength of others' disconfirming opinions to alter confidence in judgments, but adequate use when opinions are confirmatory. This bias is related to reduced neural sensitivity to the strength of others' opinions in the posterior medial prefrontal cortex when opinions are disconfirming. Our results demonstrate that existing judgments alter the neural representation of information strength, leaving the individual less likely to alter opinions in the face of disagreement