Interactive Tutorials For Upper Level Quantum Mechanics Courses

This thesis explores the ongoing need for interactive tutorials in the upper level undergraduate Quantum Mechanics course. It first summarizes the development and evaluation of tutorials at the introductory physics level by others, and then challenges the belief that upper level students do not need this type of intervention by citing research in student difficulties in learning Quantum Mechanics. Physics Education research shows that there are common student misconceptions that persist even in the upper level undergraduate courses such as Quantum Mechanics. Cognitive research serves as a guide for effective curriculum design. A description of the iterative process for developing and evaluating the tutorials is discussed. The development and evaluation of "The Time Evolution of a Wave Function" Quantum Interactive Learning Tutorial (QuILT) is described in detail. Finally, the success of the QuILT in reducing the common misconceptions about time evolution is discussed

Amputation-induced reactive oxygen species are required for successful Xenopus tadpole tail regeneration.

Understanding the molecular mechanisms that promote successful tissue regeneration is critical for continued advancements in regenerative medicine. Vertebrate amphibian tadpoles of the species Xenopus laevis and Xenopus tropicalis have remarkable abilities to regenerate their tails following amputation, through the coordinated activity of numerous growth factor signalling pathways, including the Wnt, Fgf, Bmp, Notch and TGF-β pathways. Little is known, however, about the events that act upstream of these signalling pathways following injury. Here, we show that Xenopus tadpole tail amputation induces a sustained production of reactive oxygen species (ROS) during tail regeneration. Lowering ROS levels, using pharmacological or genetic approaches, reduces the level of cell proliferation and impairs tail regeneration. Genetic rescue experiments restored both ROS production and the initiation of the regenerative response. Sustained increased ROS levels are required for Wnt/β-catenin signalling and the activation of one of its main downstream targets, fgf20 (ref. 7), which, in turn, is essential for proper tail regeneration. These findings demonstrate that injury-induced ROS production is an important regulator of tissue regeneration

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Intimate talk between parents and their teenage children : democratic openness or covert control?

In so far as modern families subscribe to an ideal of democracy, then adolescence is a time in which the democratic ideal in the family becomes an object of explicit focus as parents and teenagers strive towards a renegotiation of their relative positions. Teenagers need to develop their adult identities and a sense of agency, while at the same time, parents who have invested both personally and financially in their children must reconsider this relationship and come to terms with the reality of the returns from that investment. Intimate relations imply both democracy and equality: in what Giddens (1992) calls the ‘pure relationship’, individuals continuously reevaluate the relationship in terms of the satisfactions which it delivers in their ‘project of the self’. This paper argues that the twin ideals of democracy and intimacy necessarily clash in parent-teenager relationships, resulting in a further complication of the negotiation processes already identified in previous research (Brannen, 1999; Brannen et al., 1994; Hofer et al., 1999).While both parents and their teenage children subscribe to the discourse of openness and honesty as the route to both intimacy and democracy, there are tensions within the concept of openness because both parties have opposing goals in the trading of information. For parents, information gain means the retention of power and control, while for teenagers, with-holding information from their parents ensures their privacy, power and identity

Optimising urinary catecholamine metabolite diagnostics for neuroblastoma

IntroductionThe analysis of urinary catecholamine metabolites is a cornerstone of neuroblastoma diagnostics. Currently, there is no consensus regarding the sampling method, and variable combinations of catecholamine metabolites are being used. We investigated if spot urine samples can be reliably used for analysis of a panel of catecholamine metabolites for the diagnosis of neuroblastoma.MethodsTwenty-four-hour urine or spot urine samples were collected from patients with and without neuroblastoma at diagnosis. Homovanillic acid (HVA), vanillylmandelic acid (VMA), dopamine, 3-methoxytyramine, norepinephrine, normetanephrine, epinephrine and metanephrine were measured by high-performance liquid chromatography coupled with fluorescence detection (HPLC-FD) and/or ultra-performance liquid chromatography coupled with electrospray tandem mass spectrometry (UPLC-MS/MS).ResultsCatecholamine metabolite levels were measured in urine samples of 400 neuroblastoma patients (24-hour urine, n = 234; spot urine, n = 166) and 571 controls (all spot urine). Excretion levels of catecholamine metabolites and the diagnostic sensitivity for each metabolite were similar in 24-hour urine and spot urine samples (p > .08 and >.27 for all metabolites). The area under the receiver-operating-characteristic curve (AUC) of the panel containing all eight catecholamine metabolites was significantly higher compared to that of only HVA and VMA (AUC = 0.952 vs. 0.920, p = .02). No differences were observed in metabolite levels between the two analysis methods.ConclusionCatecholamine metabolites in spot urine and 24-hour urine resulted in similar diagnostic sensitivities. The Catecholamine Working Group recommends the implementation of spot urine as standard of care. The panel of eight catecholamine metabolites has superior diagnostic accuracy over VMA and HVA