Sustaining Educational Reforms in Introductory Physics

While it is well known which curricular practices can improve student performance on measures of conceptual understanding, the sustaining of these practices and the role of faculty members in implementing these practices are less well understood. We present a study of the hand-off of Tutorials in Introductory Physics from initial adopters to other instructors at the University of Colorado, including traditional faculty not involved in physics education research. The study examines the impact of implementation of Tutorials on student conceptual learning across eight first-semester, and seven second-semester courses, for fifteen faculty over twelve semesters, and includes roughly 4000 students. It is possible to demonstrate consistently high, and statistically indistinguishable, student learning gains for different faculty members; however, such results are not the norm, and appear to rely on a variety of factors. Student performance varies by faculty background - faculty involved in, or informed by physics education research, consistently post higher student learning gains than less-informed faculty. Student performance in these courses also varies by curricula used - all semesters in which the research-based Tutorials and Learning Assistants are used have higher student learning gains than those semesters that rely on non-research based materials and do not employ Learning Assistants.Comment: 21 pages, 4 figures, and other essential inf

Implementation of on-site velocity boundary conditions for D3Q19 lattice Boltzmann

On-site boundary conditions are often desired for lattice Boltzmann simulations of fluid flow in complex geometries such as porous media or microfluidic devices. The possibility to specify the exact position of the boundary, independent of other simulation parameters, simplifies the analysis of the system. For practical applications it should allow to freely specify the direction of the flux, and it should be straight forward to implement in three dimensions. Furthermore, especially for parallelized solvers it is of great advantage if the boundary condition can be applied locally, involving only information available on the current lattice site. We meet this need by describing in detail how to transfer the approach suggested by Zou and He to a D3Q19 lattice. The boundary condition acts locally, is independent of the details of the relaxation process during collision and contains no artificial slip. In particular, the case of an on-site no-slip boundary condition is naturally included. We test the boundary condition in several setups and confirm that it is capable to accurately model the velocity field up to second order and does not contain any numerical slip.Comment: 13 pages, 4 figures, revised versio

Is There Genetic Diversity in the ‘Leucaena Bug’ \u3cem\u3eSynergistes jonesii\u3c/em\u3e Which May Reflect Ability to Degrade Leucaena Toxins?

Leucaena leucocephala, a nutritionally rich forage tree legume, contains a non-protein amino acid, mimosine, which is degraded by ruminal bacteria to toxic metabolites 3,4-DHP and 2,3-DHP resulting in goitre-like symptoms in animals, severely restricting weight gain. Raymond Jones, in the early 1980s, discovered the ‘leucaena bug’ in the rumen of goats in Hawaii that degraded these toxic DHP metabolites into non-toxic compounds (Jones and Lowry 1984) which was named Synergistes jonesii (Allison et al. 1992) Subsequently, a rumen inoculum containing S. jonesii was used as an ‘oral drench’ for cattle, kept in continuous culture (Klieve et al. 2002) and supplied to farmers to dose cattle foraging on leucaena. Studies on Queensland herds that received this oral drench showed that up to 50% of 44 herds grazing on leucaena had apparent subclinical toxicity based on high 3,4- and 2,3-DHP excretion in urine (Dalzell et al., 2012). In another study by Graham et al. (2013), a 16S rDNA nested PCR showed that rumen digesta from 6 out of 8 properties tested had a variant DNA profile from S. jonesii ATCC 78.1 strain, which suggested a different strain of the bacterium. It was postulated that either the continually cultured oral inoculum may have undergone genetic modification and/or that animals could harbor other DHP degrading bacteria or S. jonesii strains with differential DHP degrading potential (McSweeney et al. unpublished). The present study looks at changes in the 16S rDNA gene at the molecular level that may suggest divergence from the type strain S. jonesii 78.1 (ATCC) in Queensland cattle as well as in cattle and other ruminants, internationally. These changes can appear as discrete mutations or ‘single nucleotide polymorphisms’ (SNPs) and may be correlated to their ability to degrade DHP, relative to the type strain

Pregnancy and childbirth in English prisons : institutional ignominy and the pains of imprisonment

© 2020 The Authors. Sociology of Health & Illness published by John Wiley & Sons Ltd on behalf of Foundation for SHIL.With a prison population of approximately 9000 women in England, it is estimated that approximately 600 pregnancies and 100 births occur annually. Despite an extensive literature on the sociology of reproduction, pregnancy and childbirth among women prisoners is under‐researched. This article reports an ethnographic study in three English prisons undertaken in 2015‐2016, including interviews with 22 prisoners, six women released from prison and 10 staff members. Pregnant prisoners experience numerous additional difficulties in prison including the ambiguous status of a pregnant prisoner, physical aspects of pregnancy and the degradation of the handcuffed or chained prisoner during visits to the more public setting of hospital. This article draws on Erving Goffman's concepts of closed institutions, dramaturgy and mortification of self, Crewe et al.'s work on the gendered pains of imprisonment and Crawley's notion of ‘institutional thoughtlessness’, and proposes a new concept of institutional ignominy to understand the embodied situation of the pregnant prisoner.Peer reviewe

Combining frequency and time domain approaches to systems with multiple spike train input and output

A frequency domain approach and a time domain approach have been combined in an investigation of the behaviour of the primary and secondary endings of an isolated muscle spindle in response to the activity of two static fusimotor axons when the parent muscle is held at a fixed length and when it is subjected to random length changes. The frequency domain analysis has an associated error process which provides a measure of how well the input processes can be used to predict the output processes and is also used to specify how the interactions between the recorded processes contribute to this error. Without assuming stationarity of the input, the time domain approach uses a sequence of probability models of increasing complexity in which the number of input processes to the model is progressively increased. This feature of the time domain approach was used to identify a preferred direction of interaction between the processes underlying the generation of the activity of the primary and secondary endings. In the presence of fusimotor activity and dynamic length changes imposed on the muscle, it was shown that the activity of the primary and secondary endings carried different information about the effects of the inputs imposed on the muscle spindle. The results presented in this work emphasise that the analysis of the behaviour of complex systems benefits from a combination of frequency and time domain methods

Is liver transplantation 'out-of-hours' non-inferior to 'in-hours' transplantation? A retrospective analysis of the UK Transplant Registry

OBJECTIVES: Increased morbidity and mortality have been associated with weekend and night-time clinical activity. We sought to compare the outcomes of liver transplantation (LT) between weekdays and weekends or night-time and day-time to determine if 'out-of-hours' LT has acceptable results compared with 'in-hours'. DESIGN, SETTING AND PARTICIPANTS: We conducted a retrospective analysis of patient outcomes for all 8816 adult, liver-only transplants (2000-2014) from the UK Transplant Registry. OUTCOME MEASURES: Outcome measures were graft failure (loss of the graft with or without death) and transplant failure (either graft failure or death with a functioning graft) at 30 days, 1 year and 3 years post-transplantation. The association of these outcomes with weekend versus weekday and day versus night transplantation were explored, following the construction of a risk-adjusted Cox regression model. RESULTS: Similar patient and donor characteristics were observed between weekend and weekday transplantation. Unadjusted graft failure estimates were 5.7% at 30 days, 10.4% at 1 year and 14.6% at 3 years; transplant failure estimates were 7.9%, 15.3% and 21.3% respectively.A risk-adjusted Cox regression model demonstrated a significantly lower adjusted HR (95% CI) of transplant failure for weekend transplant of 0.77 (0.66 to 0.91) within 30 days, 0.86 (0.77 to 0.97) within 1 year, 0.89 (0.81 to 0.99) within 3 years and for graft failure of 0.81 (0.67 to 0.97) within 30 days. For patients without transplant failure within 30 days, there was no weekend effect on transplant failure. Neither night-time procurement nor transplantation were associated with an increased hazard of transplant or graft failure. CONCLUSIONS: Weekend and night-time LT outcomes were non-inferior to weekday or day-time transplantation, and we observed a possible small beneficial effect of weekend transplantation. The structure of LT services in the UK delivers acceptable outcomes 'out-of-hours' and may offer wider lessons for weekend working structures