The Effects of Mathematics Placement on Successful Completion of an Engineering Degree and how One Student Beat the Odds

This dissertation comprises a sequential explanatory mixed methods study seeking to understand persistence in engineering based on a student’s initial mathematics course and the experience of a student who began in the lowest level mathematics course and completed an engineering degree despite struggling in mathematics courses. The first phase of the quantitative piece examines one year retention rates for first year engineering students based on initial mathematics course. In the second quantitative phase a stepwise logistic regression model was conducted to determine what factors are related to engineering persistence. The third quantitative phase is a retrospective study to determine the initial mathematics course for graduating engineering students. The final phase of the quantitative piece examines graduation rates for first year engineering students based on initial mathematics course. Results of the first phase indicate engineering students starting in non-college level mathematics courses are significantly less likely to be retained in engineering a year after their first semester compared to students starting in one of the calculus courses. In the logistic regression model with initial math course, grade in the initial math course, gender and race as predictor variables, course, grade, and gender were found to significantly predict retention in engineering one year later. Results from the third phase indicate very few students graduating with an engineering degree start in precalculus. It also shows some engineering disciplines may be more attainable for students starting in non-college level mathematics courses, like precalculus. Results of graduation rates in the fourth quantitative phase confirm engineering students starting in precalculus are significantly less likely to graduate with an engineering degree than those starting in any higher level mathematics course. A case study was conducted to fully explain how a student persisted in engineering after starting in precalculus. One of the few students starting in precalculus who graduated with an engineering degree was interviewed to understand why he chose engineering, why he didn’t quit or change majors when he had to repeat calculus II multiple times, and how he was able to complete his calculus courses despite his mathematical deficiencies. Other individuals who he indicated were influential in his success were also interviewed. A framework combining future time perspective and self-regulation was used to explain his experience and why he didn’t quit. Another framework on self-regulated learning strategies was used to explain how he was able to successfully complete calculus II. The case study student’s dream of becoming a pilot in the Air Force and his ‘can’t quit’ attitude were the motivation for his persistence in engineering. An instruc-tor in the Mathematical Sciences Department and the instructor’s ability to model self-regulation strategies were instrumental in the student’s eventual completion of an engineering degree. By understanding the experience of one of the few successful engi-neering students who started in a non-college level mathematics course, educators can better advise future students with similarly poor mathematics backgrounds

Technology in Mathematics Education and Ti-Navigator in the Mathematics Classroom

Over the past couple of decades, several studies have shown that mathematics achievement in the U.S. is either stagnate or declining while achievement in mathematics education in other countries has been improving. The current state of mathematics achievement on our nation is particularly daunting at a time when knowledge of mathematics is becoming increasingly important to acquire quality jobs. Some researchers believe that the lack of mathematics achievement may negatively affect technological developments and the standard of living in the U.S. One particularly promising technique may be the infusion of technology into mathematics classrooms. The proper use of technology may help raise mathematics achievement and interest in mathematics. More specifically, graphing calculators and the TI-Navigator can be used by teachers to help show increased interest in mathematics subjects and increased conceptual understanding of the material. A PowerPoint presentation summarizing the importance of mathematics and STEM education in the U.S. was developed for this project. The PowerPoint also highlighted material from the creation of a 3 hour staff development introducing the TI-Navigator to mathematics and science teachers

Oscillating Airfoil Velocity Field During Large Amplitude Dynamic Stall

The leading edge flow field of an airfoil executing a. sinusoidal oscillatory motion and experiencing dynamic stall under compressibility conditions has been studied using a two component LDV system. Phase averaged mean velocity measurements and some flow quantities derived from it are presented and discussed. The results indicate extremely large accelerations of the flow are present around the leading edge with mean velocity values 60% higher than and instantaneous velocities as large as 1. 75 times the free stream velocity. The velocity profiles at certain locations over the airfoil resemble that of a wake

Integrirano planiranje opskrbe električnom energijom, plinom i toplinskom energijom u općini

This paper presents the results of a case study to investigate different alternatives for the energy supply to a municipality on the western coast of Norway. The following alternatives for energy supply are modelled and analysed: i) a district heating system with three different heat centrals, ii) a natural gas distribution system and iii) a low temperature distribution system. The case study is performed with the optimization model "eTransport" developed for the planning of local energy systems where several alternative energy carriers and technologies are considered simultaneously. The model minimizes the total energy system cost of meeting the demands of electricity, heating, cooling and gas within a geographical area over a given planning horizon. The model uses a detailed network representation of infrastructures to consider investments in distributed central stations, components, cables and pipelines. The object function includes investments, operating and environmental costs.Ovaj članak prezentira rezultate analize slučaja koja istražuje razne alternative za opskrbu energije jedne općine na zapadnoj obali Norveške. Sljedeće alternative za opskrbu energije su modelirane i analizirane: i) Područno grijanje s tri različite toplane ii) Distribucijski sustav za prirodni plin iii) Niskotemperaturni distribucijski sustav. Analiza slučaja je napravljena pomoću optimizacijskog modela „eTransport“ razvijenog za planiranje lokalnih energetskih sustava s primjenom raznih nosioca energije i tehnologija. Model minimizira cijenu sustava koji zadovoljava potrebu za električnom i toplinskom energijom, hlađenjem i plinom u nekom geografskom području za vrijeme planiranja. Model koristi detaljnu reprezentaciju mrežne infrastrukture da uzme u obzir investiciju u toplane, komponente, troškove okoliša i operativne troškove

Both Horatio and Polonius: Innate lymphoid cells in tissue homeostasis and repair

Innate lymphoid cells (ILCs) have emerged as critical tissue-resident lymphocytes that coordinate responses to environmental stress and injury. Traditionally, their function was thought to mirror adaptive lymphocytes that respond to specific pathogens. However, recent work has uncovered a more central role for ILCs in maintaining homeostasis even in the absence of infection. ILCs are now better conceptualized as an environmental rheostat that helps maintain the local tissue setpoint during environmental challenge by integrating sensory stimuli to direct homeostatic barrier and repair programs. In this article, we trace the developmental origins of ILCs, relate how ILCs sense danger signals, and describe their subsequent engagement of appropriate repair responses using a general paradigm of ILCs functioning as central controllers in tissue circuits. We propose that these interactions form the basis for how ILC subsets maintain organ function and organismal homeostasis, with important implications for human health

Presenting video recordings of newborn resuscitations in debriefings for teamwork training

Background: The Neonatal Resuscitation Program (NRP) and similar courses have been used to train clinicians. However, formal teamwork training was not included in these courses, and their effectiveness has been questioned. In adult resuscitation, debriefings using video recordings have improved outcomes, but recordings of neonatal resuscitation have been used primarily for research

How the Selfish Brain Organizes its Supply and Demand

During acute mental stress, the energy supply to the human brain increases by 12%. To determine how the brain controls this demand for energy, 40 healthy young men participated in two sessions (stress induced by the Trier Social Stress Test and non-stress intervention). Subjects were randomly assigned to four different experimental groups according to the energy provided during or after stress intervention (rich buffet, meager salad, dextrose-infusion and lactate-infusion). Blood samples were frequently taken and subjects rated their autonomic and neuroglycopenic symptoms by standard questionnaires. We found that stress increased carbohydrate intake from a rich buffet by 34 g (from 149 ± 13 g in the non-stress session to 183 ± 16 g in the stress session; P < 0.05). While these stress-extra carbohydrates increased blood glucose concentrations, they did not increase serum insulin concentrations. The ability to suppress insulin secretion was found to be linked to the sympatho-adrenal stress-response. Social stress increased concentrations of epinephrine 72% (18.3 ± 1.3 vs. 31.5 ± 5.8 pg/ml; P < 0.05), norepinephrine 148% (242.9 ± 22.9 vs. 601.1 ± 76.2 pg/ml; P < 0.01), ACTH 184% (14.0 ± 1.3 vs. 39.8 ± 7.7 pmol/l; P < 0.05), cortisol 131% (5.4 ± 0.5 vs. 12.4 ± 1.3 μg/dl; P < 0.01) and autonomic symptoms 137% (0.7 ± 0.3 vs. 1.7 ± 0.6; P < 0.05). Exogenous energy supply (regardless of its character, i.e., rich buffet or energy infusions) was shown to counteract a neuroglycopenic state that developed during stress. Exogenous energy did not dampen the sympatho-adrenal stress-responses. We conclude that the brain under stressful conditions demands for energy from the body by using a mechanism, which we refer to as “cerebral insulin suppression” and in so doing it can satisfy its excessive needs

Spatial population expansion promotes the evolution of cooperation in an experimental Prisoner's Dilemma

Cooperation is ubiquitous in nature, but explaining its existence remains a central interdisciplinary challenge. Cooperation is most difficult to explain in the Prisoner's Dilemma game, where cooperators always lose in direct competition with defectors despite increasing mean fitness. Here we demonstrate how spatial population expansion, a widespread natural phenomenon, promotes the evolution of cooperation. We engineer an experimental Prisoner's Dilemma game in the budding yeast Saccharomyces cerevisiae to show that, despite losing to defectors in nonexpanding conditions, cooperators increase in frequency in spatially expanding populations. Fluorescently labeled colonies show genetic demixing of cooperators and defectors, followed by increase in cooperator frequency as cooperator sectors overtake neighboring defector sectors. Together with lattice-based spatial simulations, our results suggest that spatial population expansion drives the evolution of cooperation by (1) increasing positive genetic assortment at population frontiers and (2) selecting for phenotypes maximizing local deme productivity. Spatial expansion thus creates a selective force whereby cooperator-enriched demes overtake neighboring defector-enriched demes in a "survival of the fastest". We conclude that colony growth alone can promote cooperation and prevent defection in microbes. Our results extend to other species with spatially restricted dispersal undergoing range expansion, including pathogens, invasive species, and humans

Tissue signals imprint ILC2 identity with anticipatory function.

Group 2 innate lymphoid cells (ILC2s) are distributed systemically and produce type 2 cytokines in response to a variety of stimuli, including the epithelial cytokines interleukin (IL)-25, IL-33, and thymic stromal lymphopoietin (TSLP). Transcriptional profiling of ILC2s from different tissues, however, grouped ILC2s according to their tissue of origin, even in the setting of combined IL-25-, IL-33-receptor-, and TSLP-receptor-deficiency. Single-cell profiling confirmed a tissue-organizing transcriptome and identified ILC2 subsets expressing distinct activating receptors, including the major subset of skin ILC2s, which were activated preferentially by IL-18. Tissue ILC2 subsets were unaltered in number and expression in germ-free mice, suggesting that endogenous, tissue-derived signals drive the maturation of ILC2 subsets by controlling expression of distinct patterns of activating receptors, thus anticipating tissue-specific perturbations occurring later in life