Linked-Class Problem-Based Learning In Engineering: Method And Evaluation

Problem-Based Learning (PBL) is a problem-centered teaching method with exciting potential in engineering education for motivating and enhancing student learning. Implementation of PBL in engineering education has the potential to bridge the gap between theory and practice. Two common problems are encountered when attempting to integrate PBL into the undergraduate engineering classroom:  1) the large time requirement to complete a significant, useful problem and 2) the ability to determine its impact on students. Engineering, mathematics, and science professors at West Texas A&M University (WTAMU) have overcome the large time commitment associated with implementation of PBL in a single course by integrating small components of the larger project into each of their classes and then linking these components with a culminating experience for all the classes. Most of the engineering students were concurrently enrolled in the engineering, mathematics, and science classes and were therefore participating in all activities related to the project. This linked-class PBL experience addressed course concepts, reinforced connections among the courses, and provided real-world applications for the students. Students viewed the experience as beneficial, increasing their understanding of content and applications in each discipline. This paper provides details about implementation and evaluation of one PBL project and how difficulties in evaluation of the linked-class PBL experiences are being addressed

Hydrostatic Pressure Project: Linked-Class Problem-Based Learning In Engineering

Over the last few years, WTAMU Mathematics, Engineering and Science faculty has used interdisciplinary projects as the basis for implementation of a linked-class approach to Problem-Based Learning (PBL). A project that has significant relevance to engineering statics, fluid mechanics, and calculus is the Hydrostatic Pressure Project. This project was developed by faculty associated with the NSF-funded INCRSE project, Increasing Numbers and Connections in Science, Math, and Engineering, for application of the linked-class PBL to calculus II and engineering statics. The students in the linked classes were to predict the horizontal force and the vertical force on a submerged surface and determine the appropriate locations of these forces in order to experimentally verify the calculations. They worked in groups to outline their procedures, develop their functional relations, record experimental data, and report on their findings. Assessment efforts have focused on student laboratory reports and student perceptions about their learning and experiences with this linked-class PBL project collected through surveys and focus groups. In all the surveys and focus groups conducted with students who had participated in the Hydrostatic Pressure Project, all of the students felt their experience was beneficial and had enhanced their understanding and applications of engineering and mathematics

Exercise is medicine? Most of the time for most; but not always for all

Based on extensive research on the relationship between exercise and health, exercise as a form of medicine is a powerful concept of growing popularity within healthcare, academia and policy. Proponents of this exercise is medicine (EiM) movement frame exercise as a panacea for a variety of health issues and uncritically promote exercise as good for all. Two clinical populations particularly influenced by the EiM agenda are spinal cord injury (SCI) and arthritis. The purpose of this research was to explore how individuals with SCI and arthritis personally make sense of their exercise experiences. Data were collected through semi-structured interviews with participants with SCI and 20 participants with arthritis. Following a thematic narrative analysis, three patterns were identified across the whole data set. These were: 1) exercise and restitution; 2) exercise and pain; and 3) exercise and pleasure. Taken together, these results provide new knowledge regarding the impact of exercise that both align with, and contrast, the dominant EiM discourse. When exercise is perceived as ‘medicine’, stories of exercise participation spoke of cure, and restitution, rather than health and well-being. Pain was an unwelcomed side effect of exercise participation for some, and had a detrimental impact upon motivation and engagement. Lastly, a focus upon the medicinal benefits of exercise did not reflect the multiple pleasures experienced through exercise participation. Thus, health professionals, academics and policy makers need to prescribe to more ethical forms of exercise promotion that may lead to more efficacious, person-sensitive interventions

HIV infection is associated with elevated biomarkers of immune activation in Ugandan adults with pneumonia.

IntroductionPneumonia is an important cause of morbidity and mortality in persons living with human immunodeficiency virus (HIV) infection. How immune activation differs among HIV-infected and HIV-uninfected adults with pneumonia is unknown.MethodsThe Inflammation, Aging, Microbes, and Obstructive Lung Disease (I AM OLD) Cohort is a prospective cohort of adults with pneumonia in Uganda. In this cross-sectional analysis, plasma was collected at pneumonia presentation to measure the following 12 biomarkers: interleukin 6 (IL-6), soluble tumor necrosis factor receptors 1 and 2 (sTNFR-1 and sTNFR-2), high sensitivity C-reactive protein (hsCRP), fibrinogen, D-dimer, soluble CD27 (sCD27), interferon gamma-inducible protein 10 (IP-10), soluble CD14 (sCD14), soluble CD163 (sCD163), hyaluronan, and intestinal fatty acid binding protein. We asked whether biomarker levels differed between HIV-infected and HIV-uninfected participants, and whether higher levels of these biomarkers were associated with mortality.ResultsOne hundred seventy-three participants were enrolled. Fifty-three percent were HIV-infected. Eight plasma biomarkers-sTNFR-1, sTNFR-2, hsCRP, D-dimer, sCD27, IP-10, sCD14, and hyaluronan-were higher among participants with HIV infection, after adjustment for pneumonia severity. Higher levels of 8 biomarkers-IL-6, sTNFR-1, sTNFR-2, hsCRP, IP-10, sCD14, sCD163, and hyaluronan-were associated with increased 2-month mortality.ConclusionsAs in other clinical contexts, HIV infection is associated with a greater degree of immune activation among Ugandan adults with pneumonia. Some of these are also associated with short-term mortality. Further study is needed to explore whether these biomarkers might predict poor long-term outcomes-such as the development of obstructive lung disease-in patients with HIV who have recovered from pneumonia

Characterization of transitional memory CD4+ and CD8+ T-cell mobilization during and after an acute bout of exercise

T-cell subsets, including naïve (NA), central memory (CM), transitional memory (TM), effector memory (EM), and RA + effector memory (EMRA), differ in phenotype and function. T-cells are mobilized by exercise, with differences in the magnitude of mobilization between subsets. However, the response of TM T-cells to exercise has not yet been described. Further, T-cells expressing the late differentiation marker CD57 are known to be highly responsive to exercise, but the relative response of CD57 + and CD57- within T-cell subsets is unknown. We therefore aimed to characterize the exercise-induced mobilization of TM T-cells, as well as to compare the exercise response of CD57 + and CD57- cells within T-cell subsets.MethodsSeventeen participants (7 female; aged 18–40 years) cycled 30 min at 80% of their estimated maximum heart rate. Venous blood obtained pre, post, and 1H post-exercise was analyzed by flow cytometry. CD45RA, CCR7, and CD28 expression within CD4 + and CD8+ T-cells identified NA, CM, TM, EM, and EMRA subsets. CD57 expression within EM, EMRA, and CD28+ T-cells was also quantified. The relative mobilization of each subset was compared by calculating fold change in cell concentration during (ingress, post/pre) and after exercise (egress,1H post/post). Cytomegalovirus (CMV) serostatus was determined by ELISA and was considered in models.ResultsTM CD8+ T-cell concentration was greater post-exercise than pre-exercise (138.59 ± 56.42 cells/µl vs. 98.51 ± 39.68 cells/µl, p < 0.05), and the proportion of CD8 + with a TM phenotype was elevated 1H post-exercise (1H: 32.44 ± 10.38% vs. Pre: 30.15 ± 8.77%, p < 0.05). The relative mobilization during and after exercise of TM T-cells did not differ from NA and CM but was less than EM and EMRA subsets. Similar results were observed within CD4+ T-cells. CD57 + subsets of CD28+ T-cells and of EM and EMRA CD8+ T-cells exhibited a greater relative mobilization than CD57- subsets (all p < 0.05).ConclusionThese results indicate TM CD4 + and CD8+ T-cells are transiently mobilized into the blood with exercise, but not to as great of an extent as later differentiated EM and EMRA T-cells. Results also indicate CD57 identifies highly exercise responsive cells within CD8+ T-cell subsets

Chemical Cartography of the Sagittarius Stream with Gaia

The stellar stream connected to the Sagittarius (Sgr) dwarf galaxy is the most massive tidal stream that has been mapped in the Galaxy, and is the dominant contributor to the outer stellar halo of the Milky Way. We present metallicity maps of the Sgr stream, using 34,240 red giant branch stars with inferred metallicities from Gaia BP/RP spectra. This sample is larger than previous samples of Sgr stream members with chemical abundances by an order of magnitude. We measure metallicity gradients with respect to Sgr stream coordinates $(\Lambda, B)$, and highlight the gradient in metallicity with respect to stream latitude coordinate $B$, which has not been observed before. We find $\nabla \mathrm{[M/H]} = -2.48 \pm 0.08 \times 10^{-2}$ dex/deg above the stream track ($B>B_0$ where $B_0=1.5$ deg is the latitude of the Sgr remnant) and $\nabla \mathrm{[M/H]} =- 2.02 \pm 0.08 \times 10^{-2}$ dex/deg below the stream track ($B<B_0$). By painting metallicity gradients onto a tailored N-body simulation of the Sgr stream, we find that the observed metallicities in the stream are consistent with an initial radial metallicity gradient in the Sgr dwarf galaxy of $\sim -0.1$ to $-0.2$ dex/kpc, well within the range of observed metallicity gradients in Local Group dwarf galaxies. Our results provide novel observational constraints for the internal structure of the dwarf galaxy progenitor of the Sgr stream. Leveraging new large datasets in conjunction with tailored simulations, we can connect the present day properties of disrupted dwarfs in the Milky Way to their initial conditions.Comment: 20 pages, 12 figures. Submitted to ApJ; comments welcome

Ecosystem-bedrock interaction changes nutrient compartmentalization during early oxidative weathering

Ecosystem-bedrock interactions power the biogeochemical cycles of Earth's shallow crust, supporting life, stimulating substrate transformation, and spurring evolutionary innovation. While oxidative processes have dominated half of terrestrial history, the relative contribution of the biosphere and its chemical fingerprints on Earth's developing regolith are still poorly constrained. Here, we report results from a two-year incipient weathering experiment. We found that the mass release and compartmentalization of major elements during weathering of granite, rhyolite, schist and basalt was rock-specific and regulated by ecosystem components. A tight interplay between physiological needs of different biota, mineral dissolution rates, and substrate nutrient availability resulted in intricate elemental distribution patterns. Biota accelerated CO2 mineralization over abiotic controls as ecosystem complexity increased, and significantly modified stoichiometry of mobilized elements. Microbial and fungal components inhibited element leaching (23.4% and 7%), while plants increased leaching and biomass retention by 63.4%. All biota left comparable biosignatures in the dissolved weathering products. Nevertheless, the magnitude and allocation of weathered fractions under abiotic and biotic treatments provide quantitative evidence for the role of major biosphere components in the evolution of upper continental crust, presenting critical information for large-scale biogeochemical models and for the search for stable in situ biosignatures beyond Earth.Comment: 41 pages (MS, SI and Data), 16 figures (MS and SI), 6 tables (SI and Data). Journal article manuscrip

Coping and support-seeking in out-of-home care: A qualitative study of the views of young people in care in England

Objectives Young people who have been removed from their family home and placed in out-of-home care have commonly experienced abuse, neglect and/or other forms of early adversity. High rates of mental health difficulties have been well documented in this group. The aim of this research was to explore the experiences of these young people within the care system, particularly in relation to support-seeking and coping with emotional needs, to better understand feasible and acceptable ways to improve outcomes for these young people. Design and study setting This study used 1:1 semistructured qualitative interviews with young people in out-of-home care in England, to provide an in-depth understanding of their views of coping and support for their emotional needs, both in terms of support networks and experiences with mental health services. Participants were 25 young people aged 10-16 years old (56% female), and included young people living with non-biological foster carers, kinship carers and in residential group homes. Results Participants described positive (eg, feeling safe) and negative (eg, feeling judged) aspects to being in care. Carers were identified as the primary source of support, with a supportive adult central to coping. Views on support and coping differed for young people who were experiencing more significant mental health difficulties, with this group largely reporting feeling unsupported and many engaging in self-harm. The minority of participants had accessed formal mental health support, and opinions on usefulness were mixed. Conclusions Results provide insight, from the perspective of care-experienced young people, about both barriers and facilitators to help-seeking, as well as avenues for improving support