Structured Pairing in a First-Year Electrical and Computer Engineering Laboratory: The Effects on Student Retention, Attitudes, and Teamwork

This paper describes a simple technique, structured pairing, for organizing student teams in engineering instructional laboratories. This technique was adapted from pair programming, which was previously found to improve student confidence, satisfaction, and retention in computer science. A study of structured pairing was implemented in a large required course for first-year students in electrical and computer engineering. Six laboratory sections implemented structured pairing, and the other seven laboratory sections operated in a traditional way (i.e., unstructured team interactions). Data were collected from a student survey, two focus groups, and course enrollment records. Structured pairing students reported significantly higher confidence in laboratory tasks and satisfaction with the course and teamwork experiences. Focus group data indicated that structured pairing students experienced reciprocal scaffolding (i.e., students acknowledged that they learned from each other). Short-term retention in engineering did not differ significantly between structured pairing and traditional section students. These findings suggest that structured pairing is a more engaging and motivating alternative to traditional laboratory teaming methods

A Cross-Case Analysis of Disciplinary Identities Communicated Through Design Reviews

In post-secondary educational settings, discourse is a mechanism by which students develop occupational identities as they engage in a particular community that communicates attributes of their prospective profession. This study focuses on revealing disciplinary identities and how they are conveyed and negotiated during interactions between design students and project reviewers. We draw upon Gee’s identity framework and focus on the enactments of disciplinary identity in three different disciplinary settings: choreography, industrial design, and mechanical engineering. A cross-case analysis indicated differences that were epistemological (e.g., subjectivity of reviews) and similarities in ways instructors modeled institutional identities. The results have implications for interdisciplinary activities and suggest that disciplines that engage in design have much to learn from one another

Impact of Indigenous Methods of Preparation and Cooking on the Proximate, Mineral, Vitamins, Amino and Fatty Acids Compositions of Groundnut Soups Prepared in Cross River State, Nigeria

Impact of variable standard preparation methods on the proximate, vitamins, fatty acids, minerals and amino acids compositions of groundnut soups were assessed using standard methods. Toasted groundnut soups (TGS) and raw groundnut soups (RGS) were rich in arginine (2.19 ± 0.00 % and 3.57 ±0.00 %) and leucine (1.37 ± 0.00 % and 2.80 ±0.00 %) respectively. TGS had significantly (p<0.05) higher Phosphorus 51±0.12; Potassium 186 ±0.41; Magnesium 18 ±4.10; Calcium 45 ±1.21 and Sodium. Cupper, iron and Zinc were comparable in both soups. The soups were rich in fatty acids, oleic, linoleic and palmitic acids. The protein content of RGS (10.9 ±0.08 %) and TGS (10.1 ±0.04 %) were not comparable (P>0.05). The soups were rich in dietary fibre, fats and energy. RGS had higher α-carotenoids, β-carotenoids, β-cryptoxanthin and vitamin A contents. The soups have variable but rich nutrients needed for optimal body function. Keywords: Groundnuts, soups, amino acid, fatty acid, proximate mineral DOI: 10.7176/FSQM/102-05 Publication date: November 30th 202

Enhancement of CO2/CH4 separation performances of 6FDA-based co-polyimides mixed matrix membranes embedded with UiO-66 nanoparticles

Metal-organic frameworks (MOFs) incorporation into mixed matrix membranes (MMMs) is gaining more attention due to the combined advantages of high separation performance and easy processability. Nanoparticles (NPs) of CO2-philic MOF UiO-66 (Zr-BDC) were synthesized with high surface area and ca. 50 nm particle size (and also for comparison with 100 and 200 nm sizes). They were incorporated into three 6FDA-based co-polyimides (namely 6FDA-BisP, 6FDA-ODA, and 6FDA-DAM), forming MMMs with loadings in the 4–23 wt% range. The NPs and MMMs were characterized accordingly by XRD, BET, SEM, TEM, FTIR, and TGA. CO2 and CH4 isotherms on the NPs were measured by a static volumetric method at the pressure up to 10 bar. Fractional free volume (FFV) was calculated using solid density, measured by pycnometer. Gas separation performance was evaluated using a feed composition of 50%:50% CO2:CH4 binary mixture at 35 °C and a pressure difference of 2 bar. The presence of UiO-66 NPs in the continuous 6FDA-BisP and 6FDA-ODA co-polyimides improved both CO2 permeability and CO2/CH4 selectivity by 50–180% and 70–220%, respectively. In the case of 6FDA-DAM MMMs, the CO2 permeability was significantly improved by 92%, while maintaining the CO2/CH4 selectivity. The best results in terms of CO2/CH4 selectivity were 41.9 for 6FDA-BisP (17 wt% filler loading, 108 Barrer of CO2), 57.0 for 6FDA-ODA (7 wt% filler loading, 43.3 Barrer of CO2) and 32.0 for 6FDA-DAM (8 wt% filler loading, 1728 Barrer of CO2)

Expression and Function of Neurotrophins and Their Receptors in Cultured Human Keratinocytes

Whereas nerve growth factor has been extensively studied in human keratinocytes, little is known on the role of other members of the neurotrophin family. We investigated the expression and function of neurotrophins and neurotrophin receptors in cultured human keratinocytes. We demonstrated by reverse transcription–polymerase chain reaction that keratinocytes synthesize neurotrophin-3, brain-derived neurotrophic factor, and neurotrophin-4/5. These cells also express tyrosinase kinase A and C, the nerve growth factor and neuro-trophin-3 high-affinity receptors, respectively. On the other hand, only the truncated extracellular isoform of tyrosinase kinase B, the high-affinity brain-derived neurotrophic factor and neurotrophin-4/5 receptor, is detected in keratinocytes. Moreover, neurotrophin-3, brain-derived neurotrophic factor, and neurotrophin-4/5 proteins are secreted by human keratinocytes at low levels. Keratinocyte stem cells synthesize the highest amounts of nerve growth factor, while they secrete higher levels of nerve growth factor as compared with transit amplifying cells. Neurotrophin-3 stimulates keratinocyte proliferation, where brain-derived neurotrophic factor or neurotrophin-4/5 does not exert any effect on keratinocyte proliferation. Addition of neurotrophin-3 slightly upregulates the secretion of nerve growth factor, whereas nerve growth factor strongly augments neurotrophin-3 release. Ultraviolet B irradiation downregulates nerve growth factor, whereas it augments neurotrophin-3 and neurotrophin-4/5 protein levels. Ultraviolet A irradiation increases the level of neurotrophin-3, whereas it does not exert any effect on the other neurotrophins. Finally, neurotrophins other than nerve growth factor fail to protect human keratinocytes from ultraviolet B-induced apoptosis. This work delineates a functional neurotrophin network, which may contribute to epidermal homeostasis

High-pressure CO2/CH4 separation of Zr-MOFs based mixed matrix membranes

The gas separation properties of 6FDA-DAM mixed matrix membranes (MMMs) with three types of zirconium-based metal organic framework nanoparticles (MOF NPs, ca. 40 nm) have been investigated up to 20 bar. Both NPs preparation and MMMs development were presented in an earlier publication that reported outstanding CO2/CH4 separation performances (50:50 vol% CO2/CH4 feed at 2 bar pressure difference, 35 °C) and this subsequent study is to demonstrate its usefulness to the natural gas separation application. In the current work, CO2/CH4 separation has been investigated at high pressure (2–20 bar feed pressure) with different CO2 content in the feed (10–50 vol%) in the temperature range 35–55 °C. Moreover, the plasticization, competitive sorption effects, and separation of the acid gas hydrogen sulfide (H2S) have been investigated in a ternary feed mixture of CO2:H2S:CH4 (vol% ratio of 30:5:65) at 20 bar and 35 °C. The incorporation of the Zr-MOFs in 6FDA-DAM enhances both CO2 permeability and CO2/CH4 selectivity of this polymer. These MMMs exhibit high stability under separation conditions relevant to an actual natural gas sweetening process. The presence of H2S does not induce plasticization but increases the total acid gas permeability, acid gas/CH4 selectivity and only causes reversible competitive sorption. The overall study suggests a large potential for 6FDA-DAM Zr-MOF MMMs to be applied in natural gas sweetening, with good performance and stability under the relevant process conditions

Applying Phenomenography to Develop a Comprehensive Understanding of Ethics in Engineering Practice

This Work-in-Progress Research paper describes (1) the contemporary research space on ethics education in engineering; (2) our long-term research plan; (3) the theoretical underpinnings of Phase 1 of our research plan (phenomenography); and (4) the design and developmental process of a phenomenographic interview protocol to explore engineers' experiences with ethics. Ethical behavior is a complex phenomenon that is complicated by the institutional and cultural contexts in which it occurs. Engineers also have varied roles and often work in a myriad of capacities that influence their experiences with and understanding of ethics in practice. We are using phenomenography, a qualitative research approach, to explore and categorize the ways engineers experience and understand ethical engineering practice. Specifically, phenomenography will allow us to systematically investigate the range and complexity of ways that engineers experience ethics in professional practice in the health products industry. Phenomenographic data will be obtained through a specialized type of semi-structured interview. Here we introduce the design of our interview protocol and its four sections: Background, Experience, Conceptual, and Summative. We also describe our iterative process for framing questions throughout each section

Keratinocytes enriched for stem cells are protected from anoikis via an integrin signaling pathway in a Bcl-2 dependent manner

AbstractBecause inhibition of integrin signaling induces apoptosis, we investigated whether keratinocytes expressing β1 and α6β4 integrins (enriched for stem cells) are protected from cell death. Keratinocytes rapidly adhering to type IV collagen expressed highest levels of β1 and α6β4 and of the anti-apoptotic stem cell marker p63. Apoptotic cells were significantly higher in slowly adhering than in rapidly adhering keratinocytes. Anti-β1 integrin caused a significant increase in apoptotic cells, while it decreased Bcl-2 levels in stem keratinocytes. Bax and Bad proteins were higher in slowly adhering than in rapidly adhering cells. By contrast, Bcl-2, Bcl-x and Mcl-1 proteins were highest in rapidly adhering keratinocytes and nearly absent in slowly adhering cells. After addition of anti-β1 integrin, the apoptotic rate was significantly higher in HaCaT cells not expressing Bcl-2 than in controls. These results indicate that keratinocytes enriched for stem cells are protected from apoptosis via β1 integrin, in a Bcl-2 dependent manner

Слобожанщина: літературний вимір

To determine diurnal variations in the physical and biological state of Lake Garda in early spring, high-resolution measurements were made of the vertical distribution of temperature and fluorescence in the upper 100 meters during 5–7 March 2014. In this paper, the results of these measurements are presented and a preliminary analysis that focuses on the connection between the vertical mixing coefficient K_T and the chlorophyll-a (chl-a) concentration is given. From these first direct measurements of turbulence-related quantities in Lake Garda, it is found that mixed-layer values of K_Tdecrease, while surface chl-a concentrations increase, over the day. Variations in K_Tcan be connected to the changes in the surface wind stress, while variations in chl-a are negatively correlated with the amplitude of K_T. In addition, satellite observations of the surface chl-a concentration are analysed to test their use for the calibration of the fluorescence measurements and also for their potential utility in remotely determining vertical mixing in the upper layers of the lake