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Active Learning Strategies in Engineering Education in Gulf Countries
Get PDFTeaching engineering has involved numerous strategies which have been evolving over the past decades due to innovations in technology. New and fashionable educational methodologies, e-learning and wireless networked laptop technology are only the latest in a series of developments available to the engineering instructor. The Internet as a tool for acquiring information from global sources has also proved invaluable to engineering students worldwide as an aid to research in many areas of their study. Engineering departments, for their part, have responded by preparing courses that develop the skills of their students in using these technologies and methodologies.
The focus of this paper deals with active learning and new technologies in teaching students in engineering faculties in the Gulf. Furthermore, the paper examines two key educational areas. Firstly, the implementation of strategies to facilitate the transition of students from passive to active learning. Secondly, the role of educational methodologies in promoting independent and group centred learning skills as opposed to their prior experience of highly dependent learning
Regulatory Interdependence of Cloned Epithelial Na+ Channels and P2X Receptors
Get PDFEpithelial Na+ channels (ENaC) coexist with a family of ATP-gated ion channels known as P2X receptors in the renal collecting duct. Although ENaC is itself insensitive to extracellular ATP, tubular perfusion of ATP can modify the activity of ENaC. To investigate a possible regulatory relationship between P2X receptors and ENaC, coexpression studies were performed in Xenopus oocytes. ENaC generated a persistent inward Na+ current that was sensitive to the channel blocker amiloride (Iam-s). Exogenous ATP transiently activated all cloned isoforms of P2X receptors, which in some cases irreversibly inhibited Iam-s. The degree of inhibition depended on the P2X receptor subtype present. Activation of P2X2, P2X2/6, P2X4, and P2X4/6 receptor subtypes inhibited Iam-s, whereas activation of P2X1, P2X3, and P2X5 receptors had no significant effect. The degree of inhibition of Iam-s correlated positively with the amount of ionic charge conducted by P2X receptor subtypes. ENaC inhibition required Na+ influx through Iam-s-inhibiting P2X ion channels but also Ca2+ influx through P2X4 and P2X4/6 ion channels. P2X-mediated inhibition of Iam-s was found to be due to retrieval of ENaC from the plasma membrane. Maximum amplitudes of ATP-evoked P2X-mediated currents (IATP) were significantly increased for P2X2, P2X2/6, and P2X5 receptor subtypes after coexpression of ENaC. The increase in IATP was due to increased levels of plasma membrane–bound P2X receptor protein, suggesting that ENaC modulates protein trafficking. In summary, ENaC was downregulated by the activation of P2X2, P2X2/6, P2X4, and P2X4/6 receptors. Conversely, ENaC increased the plasma membrane expression of P2X2, P2X2/6, and P2X5 receptors
The Upward Path to Structural Realism
Get PDFIn a recent PSA paper (2001a), as well as some other papers (1995, 2000, 2001b) and a book chapter (1999, Chapter 7), Stathis Psillos raised a number of objections against structural realism. The aim of this paper is threefold: (1) to evaluate part of Psillos’ offence on the Russellian version of epistemic structural realism (ESR); (2) to elaborate more fully what Russellian ESR involves; and (3) to suggest improvements where it is indeed failing
Determinants of the Sensitivity of AMPA Receptors to Xenon
Get PDFBackground: There is substantial and growing literature on the actions of general anesthetics on a variety of neurotransmitter-gated ion channels, with the greatest attention being focused on inhibitory gamma-amino butyric acid type A receptors. In contrast, glutamate receptors, the most important class of fast excitatory neurotransmitter-gated receptor channels, have received much less attention, and their role in the production of the anesthetic state remains controversial.
Methods: alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors formed from a variety of different subunits were expressed in Xenopus oocytes and HEK-293 cells, and their sensitivities to the inhalational general anesthetics xenon, isoflurane, and halothane were determined using two-electrode voltage clamp and patch clamp techniques. The effects of desensitization on anesthetic sensitivity were investigated using cyclothiazide and site-directed mutagenesis. An ultrarapid application system was also used to mimic rapid high-concentration glutamate release at synapses.
Results: The authors show that xenon can potently inhibit AMPA receptors when assayed using bath application of kainate. However, when the natural neurotransmitter l-glutamate is used under conditions in which the receptor desensitization is blocked and the peak of the glutamate-activated response can be accurately measured, the pattern of inhibition changes markedly. When desensitization is abolished by a single-point mutation (L497Y in GluR1 and the equivalent mutation L505Y in GluR4), the xenon inhibition is eliminated. When AMPA receptors are activated by glutamate using an ultrarapid application system that mimics synaptic conditions, sensitivity to xenon, halothane, and isoflurane is negligible.
Conclusions: AMPA receptors, when assayed in heterologous expression systems, showed a sensitivity to inhalational anesthetics that was minimal when glutamate was applied rapidly at high concentrations. Because these are the conditions that are most relevant to synaptic transmission, the authors conclude that AMPA receptors are unlikely to play a major role in the production of the anesthetic state by inhalational agents
Active Learning Strategies in Engineering Design and Computer Aided Design Education
Get PDFTeaching the design process has involved numerous strategies which have been evolving over the past decades due to innovations in technology. New and fashionable educational methodologies, e-learning and wireless networked laptop technology are only the latest in a series of developments available to the computer aided design (CAD) instructor. The Internet as a tool for acquiring information from global sources has also proved invaluable to engineering students worldwide as an aid to research in many areas of their study, including design. Engineering departments, for their part, have responded by preparing courses that develop the skills of their students in using these technologies and methodologies.
The focus of this paper deals with the active learning and new technologies in teaching students about CAD and design. Students acquire a clear understanding of geometric construction using 2-D CAD, the fundamentals of orthographic projections using both freehand sketching and CAD software, dimensioning techniques, and isometric sketching. Students also learn 3-D solid modeling using solid primitives and Boolean operations to create composite solids. In addition, they use coordinate systems and various viewing transformations as well as develop 3-D spatial visualization skills and the ability to read and prepare engineering drawings in addition to undertaking an CAD project. Students with little or no prior skills in visualization will have developed and honed their abilities in using it as an effective design tool.
Furthermore, this course facilitates the student in two key educational areas which are evaluated in this paper. Firstly, the implementation of strategies to facilitate the transition of students from passive to active learning. Secondly, the role of educational methodologies in promoting independent and group centered learning skills as opposed to their prior experience of highly dependent learning
Is Structure Not Enough?
Get PDFThis paper counters an objection raised against one of Bertrand Russell’s lesser-known epistemological views, viz. ‘‘structural realism’’ (SR). In short, SR holds that at most we have knowledge of the structure of the external (i.e., physical) world. M. H. A. Newman’s allegedly fatal objection is that SR is either trivial or false. I argue that the accusation of triviality is itself empty since it fails to establish that SR knowledge claims are uninformative. Moreover, appealing to Quine’s notion of ontological relativity, I suggest that far from being false, SR knowledge claims seem to be the most that we can hope for
The isolated polycystin-1 cytoplasmic COOH terminus prolongs ATP-stimulated Cl–conductance through increased Ca2+entry
Get PDFThe precise steps leading from mutation of the polycystic kidney disease (PKD1) gene to the autosomal dominant polycystic kidney disease (ADPKD) phenotype remain to be established. Fluid accumulation is a requirement for cyst expansion in ADPKD, suggesting that abnormal fluid secretion into the cyst lumen might play a role in disease. In this study, we sought to establish a link between polycystin-1 (the PKD1 gene product) and ATP-stimulated Cl- secretion in renal tubule cells. To do this, we performed a whole cell patch-clamp analysis of the effects of expression of the isolated cytoplasmic COOH-terminus of polycystin-1 in stably transfected mouse cortical collecting duct cells. The truncated polycystin-1 fusion protein prolonged the duration of ATP-stimulated Cl- conductance and intracellular Ca2+ responses. Both effects were dependent on extracellular Ca2+. It was determined that expression of the truncated polycystin-1 fusion protein introduced, or activated, an ATP-induced Ca2+ entry pathway that was undetectable in transfection control cell lines. Our findings are concordant with increasing evidence for a role of polycystin-1 in cell Ca2+ homeostasis and indicate that dysregulated Ca2+ entry might promote Cl- secretion and cyst expansion in ADPKD
Attitudes to punishment: International comparisons: The evolution of public attitudes to punishment in Western Europe
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