(Re)-engaging Feminist ways of knowing through and between social (dis)locations

This paper explores the tensions and dislocations linked to my doctoral fieldwork in El Salvador. I reflect upon my experiences as an emerging community psychologist, engaging with feminist theory to frame my praxis and draw out new directions for social justice research based in ethics, witnessing and inclusive knowledge practice

Disposable microbial and animal cell bioreactors for use in a disposable biopharmaceutical manufacturing process

This thesis concerns the concept of disposables for use in the manufacture of biopharmaceuticals. A disposable process is where all the equipment in contact with the process is disposable. Specifically disposable bioreactors for microbial fermentation and animal cell culture were investigated. For the disposable microbial bioreactor, the plunging jet reactor was proposed as the best option where the thesis details the design and manufacture for a disposable plunging jet bioreactor for use in a microbial fermentation. The 14 L disposable plunging jet bioreactor was compared with a 5 L stirred tank bioreactor. The comparison was made on both the physical performance of the bioreactors and the resultant performance of the fermentation. The maximum kLa in the plunging jet bioreactor was 0.13 to 0.15 s-1, which was comparable to kLa of 0.12 s-1 in the stirred tank bioreactor. This oxygen transfer was achieved with the stirred tank operating at a maximum power per unit volume of 11.2 to 12.7 kW m-3 whilst the plunging jet bioreactor operated at a lower maximum power per unit volume of 1.4 kW m-3. The plunging jet bioreactor incurred a higher maximum shear rate of 85000 s-1, compared to the stirred tank bioreactor with a maximum shear rate of 13000 to 135000 s-1. The mode of operation to maintain the DOT above 10 to 20 [percent] for the two bioreactors was different. For the plunging jet bioreactor the kLa increases with the OUR so that bioreactor was operated with a fixed power per unit volume. Operating the stirred tank bioreactor at a fixed power per unit volume results in a kLa that is fixed whilst the OUR increases. Thus for the stirred tank the power per unit volume was periodically increased resulting in an instantaneous increase in the kLa. For the plunging jet bioreactor the kLa was affected by the position of nozzle with respect to the outlet. For the plunging jet bioreactor operating at a power per unit volume of 1.4 kW m-3, with the Fab fermentation at an OUR of 5 mol L-1 hr-1; the kLa increased from 0.005 s-1 to 0.045 s-1 as a result of moving the nozzle angle from vertical (0°) to 5° away from the outlet (i.e. to an of angle of -5°). For both the Wild Type and Fab fermentation there were distinct differences between the resultant performance of the fermenations in the stirred tank bioreactor and the plunging jet bioreactor. For the Wild Type fermentation in the plunging jet bioreactor, lysis occurred within the first 140 minutes of growth, whilst in the stirred tank bioreactor the fermentation was grown as per the protocol. Unlike with the Wild Type fermentation, the Fab fermentation was grown in both the bioreactors without lysis, where the growth in the plunging jet bioreactor was attributed to the greater strength of Fab microbial cells compared to the Wild Type microbial cells. Despite the growth of the Fab fermentation in both bioreactors, there were distinct differences in the resultant performance of the fermentation. In the plunging jet bioreactor the Fab fermentation had both a lower maximum OUR and a lower final dry weight. In addition the RQ varied between 0.5 to 1.0, where addition of glycerol resulted in an increase in the RQ. In the stirred tank bioreactor the final concentration of the Fab product was 75 mg L-1 in the solid fraction and 14 to 22 mg L-1 in the supernatant. In the plunging jet bioreactor, the final concentration of the Fab product was 0.005 mg L-1 in the supernant and zero concentration in the solid fraction. This difference in the Fab concentration between the two bioreactors was attributed to shear in the plunging jet bioreactor stripping away the outer polysaccharide layer, so that the Fab product was released and subsequently degraded in the fermentation broth. The thesis suggests that these differences in the resultant performance of the Wild Type and Fab fermentation are attributed to the higher shear rate in the plunging jet bioreactor. Further work must be performed to determine whether reducing the shear rate of the nozzle whilst maintaining the mass transfer and mixing will result in a bioreactor whose resultant performance of the fermentation is comparable with the stirred tank bioreactor. The high turbulence nozzle, developed by Kenyres has been suggested as a potential method of reducing the shear rate in the bioreactor. The plunging jet reactor, bubble column reactor and the airlift reactor were all evaluated as potential disposable animal cell bioreactors. The comparison was made on the basis of measuring the kLa, CO2 stripping and mixing versus the power per unit volume for the three reactors. The targets for the kLa, CO2 stripping and mixing were measured in the airlift at a superficial velocity of 0.01 and 0.015 ms-1 which is the typical maximum superficial velocity range that a large scale industrial airlift operates during a biopharmaceutical process. The thesis concludes that the plunging jet reactor is not suitable as a disposable animal cell bioreactor. A 6 L plunging jet reactor was operating with a maximum power per unit volume of 0.01 kW m-3 which corresponded to a shear rate and stress of 15000 s-1 and 15N m-2 respectively. Whilst the upper kLa and mixing targets of 8.9 hr-1 and 13 seconds respectively were achieved below this maximum power per unit volume, operating at the maximum power per unit volume resulted in CO2 stripping of 0.030 hr-1, which was just within the range of the lower target. Whilst the 6 L plunging jet reactor performance was limited by its CO2 stripping, the principle reason for rejecting the reactor was that there were perceived to be problems in scaling up the reactor. Increasing the scale of the reactor would probably require an increase in the nozzle diameter and the use of multiple nozzles in order to maintain a low shear rate and prevent a 'foam' in the upper part of the bioreactor. Measuring the kLa, mixing and CO2 stripping for an airlift and bubble column both of 26 L scale, showed that at small scale the two reactors had comparable performance. In terms of construction the only difference between the bubble column reactor and the airlift reactor is the presence of a divider in the latter. The proposed design for the disposable airlift shown in section 7.3 has a square cross section so that the divider is diagonal. This insures that the divider is taut and is welded along the main seams of the disposable bag. Thus the airlift's construction is not sufficiently more complex than the bubble column and thus is the preferred option for a disposable animal cell bioreactor. This is because at large scale, published work has shown that the airlift has better mixing and aeration than the bubble column so that the airlift is more scaleable. Further work is required to determine whether the proposed design will result in a 7 day animal cell culture that is comparable with the same animal culture performed in a conventional airlift or stirred tank bioreactor

On-ice measures of external load in relation to match outcome in elite female ice hockey

The aim of this study is to investigate the differences between select on-ice measures using inertial movement sensors based on match outcome, and to determine changes in player movements across three periods of play. Data were collected during one season of competition in elite female ice hockey players (N = 20). Two-factor mixed effects ANOVAs for each skating position were performed to investigate the differences in match outcome, as well as differences in external load measures during the course of a match. For match outcome, there was a small difference for forwards in explosive ratio (p = 0.02, ES = 0.26) and percentage high force strides (p = 0.04, ES = 0.50). When viewed across three periods of a match, moderate differences were found in skating load (p = 0.01, ES = 0.75), explosive efforts (p = 0.04, ES = 0.63), and explosive ratio (p = 0.002, ES = 0.87) for forwards, and in PlayerLoad (p = 0.01, ES = 0.70), explosive efforts (p = 0.04, ES = 0.63), and explosive ratio (p = 0.01, ES = 0.70) for defense. When examining the relevance to match outcome, external load measures associated with intensity appear to be an important factor among forwards. These results may be helpful for coaches and sport scientists when making decisions pertaining to training and competition strategies.York University Librarie

Augmented Block-Arnoldi Recycling CFD Solvers

One of the limitations of recycled GCRO methods is the large amount of computation required to orthogonalize the basis vectors of the newly generated Krylov subspace for the approximate solution when combined with those of the recycle subspace. Recent advancements in low synchronization Gram-Schmidt and generalized minimal residual algorithms, Swirydowicz et al.~\cite{2020-swirydowicz-nlawa}, Carson et al. \cite{Carson2022}, and Lund \cite{Lund2022}, can be incorporated, thereby mitigating the loss of orthogonality of the basis vectors. An augmented Arnoldi formulation of recycling leads to a matrix decomposition and the associated algorithm can also be viewed as a {\it block} Krylov method. Generalizations of both classical and modified block Gram-Schmidt algorithms have been proposed, Carson et al.~\cite{Carson2022}. Here, an inverse compact $WY$ modified Gram-Schmidt algorithm is applied for the inter-block orthogonalization scheme with a block lower triangular correction matrix $T_k$ at iteration $k$. When combined with a weighted (oblique inner product) projection step, the inverse compact $WY$ scheme leads to significant (over 10$\times$ in certain cases) reductions in the number of solver iterations per linear system. The weight is also interpreted in terms of the angle between restart residuals in LGMRES, as defined by Baker et al.\cite{Baker2005}. In many cases, the recycle subspace eigen-spectrum can substitute for a preconditioner

Representation of model error in a convective-scale ensemble prediction system

In this paper ensembles of forecasts (of up to six hours) are studied from a convection-permitting model with a representation of model error due to unresolved processes. The ensemble prediction system (EPS) used is an experimental convection-permitting version of the UK Met Office’s 24- member Global and Regional Ensemble Prediction System (MOGREPS). The method of representing model error variability, which perturbs parameters within the model’s parameterisation schemes, has been modified and we investigate the impact of applying this scheme in different ways. These are: a control ensemble where all ensemble members have the same parameter values; an ensemble where the parameters are different between members, but fixed in time; and ensembles where the parameters are updated randomly every 30 or 60 min. The choice of parameters and their ranges of variability have been determined from expert opinion and parameter sensitivity tests. A case of frontal rain over the southern UK has been chosen, which has a multi-banded rainfall structure. The consequences of including model error variability in the case studied are mixed and are summarised as follows. The multiple banding, evident in the radar, is not captured for any single member. However, the single band is positioned in some members where a secondary band is present in the radar. This is found for all ensembles studied. Adding model error variability with fixed parameters in time does increase the ensemble spread for near-surface variables like wind and temperature, but can actually decrease the spread of the rainfall. Perturbing the parameters periodically throughout the forecast does not further increase the spread and exhibits “jumpiness” in the spread at times when the parameters are perturbed. Adding model error variability gives an improvement in forecast skill after the first 2–3 h of the forecast for near-surface temperature and relative humidity. For precipitation skill scores, adding model error variability has the effect of improving the skill in the first 1–2 h of the forecast, but then of reducing the skill after that. Complementary experiments were performed where the only difference between members was the set of parameter values (i.e. no initial condition variability). The resulting spread was found to be significantly less than the spread from initial condition variability alone

A Framework for Agreeing Standard Terminology

This document outlines a process that can be followed to reach agreement on standard terminology for a community or topic

Recovery of Nerve Function after Treatment for Childhood Cancer

Background Chemotherapeutic agents have been the backbone treatment for pediatric cancers. Unfortunately, a number of the chemotherapy medications have potential side effects, including chemotherapy-induced peripheral neuropathy (CIPN). To measure the extent of CIPN, the Pediatric Modified Total Neuropathy Score (Peds-mTNS) has been shown to be a reliable and valid measure of CIPN in school-aged children and is associated with relevant functional limitations. However, future research is needed to describe the recovery of CIPN in children and adolescent cancer patients after treatment has ended. Purpose To analyze the trajectory of recovery for CIPN in school-aged children diagnosed with non-CNS cancers and to evaluate if diagnosis and treatment impact CIPN type and recovery. Methods Forty-seven subjects ranging in age from 5-18 years undergoing chemotherapy with vincristine or a combination of vincristine and intrathecal methotrexate participated in the study. Peds-mTNS scores as well as standardized balance and hand function measures were taken on treatment (at the anticipated peak of CIPN) and then 3 and 6 months post treatment. Descriptive statistics and one-way repeated measures ANOVA were run to compare subjects over time (on treatment, 3 months, and 6 months post). A 2-way III repeated measures ANOVA was run to compare mean Peds-mTNS scores for each diagnostic group over time. Results 18 subjects with Acute Lymphoblastic Leukemia (ALL), 8 with Wilma’ tumor, 14 with non/Hodgkin’s lymphoma and 7 with other non-CNS cancers were evaluated. Across all subjects (n=47), Peds-mTNS scores decreased significantly over time (on treatment 9.5± 4.4, 3 months 5.8 ± 4.7, 6 months 4.3 ± 4.0, p\u3c 0.001), indicating an improvement in CIPN. Overall effect size, with Partial Eta Squared, was found to be large (0.609). Greatest individual measure effect size was shown in deep tendon reflex (.659). Of the diagnostic groups, patients with Hodgkin’s lymphoma were found to have significantly less improvement on the Peds-mTNS than subjects with leukemia (6.4 ± 0.7 vs 2.2 ± 0.6 at 6 months, p\u3c0.05), even though their treatment time was shorter in duration and they received less vincristine. Conclusion Overall, the trajectory of recovery for pediatric cancer patients was found to be positive, resulting in significant improvements in CIPN symptoms over time post-treatment, although patients with Hodgkin’s lymphoma were more likely to have residual neuropathy