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The gated community motif occurs frequently within climate and environmental disaster fiction. This thesis investigates its occurrence across three media to establish how the gated community mode of living, as rendered in post-apocalyptic speculative fiction, responds to the threat and consequences of climate and environmental crisis. This thesis combines recent urban studies scholarship with ecocritical theory to analyse the gated communities present in Octavia E. Butler’s novels, The Parable of the Sower and The Parable of the Talents, Neil Blomkamp’s film, Elysium, and Naughty Dog’s video games, The Last of Us and The Last of Us: Part II. Comparative analysis of the motif in each primary narrative reveals how disaster exacerbates the security and segregation this mode of settlement makes possible, resulting in a pronounced Othering of outsiders to these communities. This essay concludes that the boundaries of these speculative gated communities come to symbolise the borders Global North, which rhetorically and physically exclude the migrant Other. As most of the gated communities in these narratives experience catastrophe and collapse at the hands of those they refuse to accept, the texts appear to warn us to expect similar results unless issues of climate justice are not addressed by the Global North today. Grindsamhället (eng. gated community) är ett vanligt förekommande motiv i berättelser om klimat- och miljökatastrofer. Den här uppsatsen undersöker motivet i tre medietyper för att diskutera hur grindsamhället som samhällsform porträtteras i postapokalyptiskt spekulativ fiktion, och hur det ses svara på klimat- och miljö- krisernas hot och konsekvenser. Uppsatsen kombinerar ekokritisk teori med modern forskning inom urbana studier för att analysera grindsamhällen som förekommer i romanerna The Parable of the Sower och The Parable of the Talents av Octavia E. Butler, Neil Blomkamps film Elysium och Naughty Dogs datorspel The Last of Us och The Last of Us: Part II. Komparativ analys av motivet i de primära berättelserna ger vid handen hur katastrofer förvärrar den säkerhet och segregation som samhälls- formen möjliggör, vilket resulterar i en uttalad syn på personer utanför samhällena som Andra. Uppsatsen slår fast att gränserna för de spekulativa grindsamhällena sym- boliserar gränserna mellan det globala nord och syd, vilket retoriskt och fysiskt ute- stänger migranter från syd och konstruerar dem som Andra. Eftersom de flesta grindsamhällen i berättelserna drabbas av katastrof och kollaps på grund av de människor som man vägrar släppa in tycks texterna varna oss för att vi kan förvänta oss något liknande om den globala norden inte ser till att hantera frågor om klimaträttvisa idag.

Intestinal Malrotation is an uncommon entity in the adult population; more so in monozygotic twins, where concordance is expected. In literature, discordant intestinal Malrotation has only been discovered when one twin became symptomatic, and the other was screened. To the best of our knowledge, this is the first documented case of discordant adult type intestinal Malrotation in otherwise asymptomatic monozygotic twins discovered incidentally during Laparoscopic Roux-en-Y Gastric bypass (LRYGB).Twins A and B met the NIH criteria for bariatric surgery, neither having symptoms of acute or chronic volvulus or history of intraabdominal surgery. Twin A had a LRYGB performed by a trained bariatric surgeon, noting no anatomic anomalies. 5 months later, Twin B had LRYGB and intestinal Malrotation was diagnosed incidentally.Diagnosis of Intestinal Malrotation is rare in adults, usually discovered after becoming symptomatic or during abdominal imaging for another indication. Two cases of discordant intestinal Malrotation in monozygotic twins have been documented, both discovered when one twin became symptomatic due to acute volvulus, suggesting epigenetic phenomena. When discovered incidentally during surgery, patients can safely undergo their intended procedure, but literature suggests prophylactic division of Ladd's bands, while appendectomy is left to the discretion of the surgeon.Intestinal Malrotation appears to be associated with epigenetic phenomena and if discovered incidentally during surgery, the proposed procedure can be carried out by an experienced surgeon, in addition to division of Ladd's bands and appendectomy.

A Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Kinesiology & Health Studies, University of Regina. xxii, 383 p. Background: The underlying causes of low back pain (LBP) have been proposed to be associated with motor control impairments that can result in compensatory movement and spinal instability. The Prone Hip Extension (PHE) Test and the Active Straight Leg Raise (ASLR) Test are clinical tools used to test for the presence of these motor control impairments. Movement and muscle activation patterns exhibited during these tests have been proposed to be representative of those employed during gait. Purpose: The purpose of this thesis was to determine the appropriateness of the PHE Test (Study 1) and ASLR Test (Study 2) in identifying motor control impairments associated with LBP, and to establish the nature of any similarities between each test and the corresponding phase of gait (Study 3). Methods: 50 (PHE) and 44 (ASLR) male and female participants (18-50 years) were recruited and assigned into an LBP or Control group. Motion capture was used to quantify the tri-planar movement of the lumbar spine and pelvis during the performance of each test and the hip extension and flexion phases of gait. Surface electromyography was used to measure the amplitude and timing of activation of the gluteus maximus (GM), hamstrings (HAM), and paraspinal (PS) muscles during the PHE Test; and the amplitude of the rectus abdominis (RA), external oblique (EO), and internal oblique (IO) muscles during the ASLR Test. Multivariate analyses of variance (MANOVAs) were used to identify which clusters of variables exhibited significant differences between the groups (LBP vs Control) and tasks (Test vs Gait). A post-hoc analysis was performed using univariate analyses of variance (ANOVAs) and discriminant function analyses (DFAs) on the variables identified by the MANOVAs. Logistic regression analyses (LRAs) were used to build predictive models of group membership (LBP vs Control) using the variables identified by the ANOVAs/DFAs. Results: Study 1: The variables that qualified for the LRA were: HAM amplitude, GM amplitude and timing of onset, frontal and transverse plane upper lumbar motion, and transverse plane lower lumbar motion during right leg motion. Significant differences (p < 0.10) in lumbo-pelvic movement patterns were generally within technological margins of error. For the muscle variables, higher activation levels were demonstrated by the LBP group. The final stage of the LRA produced a statistically significant prediction model that correctly classified 86.7% of the Control group and 83.3% of the LBP group. Study 2: The variables that qualified for the LRA were: right EO amplitude, right IO amplitude, and right RA amplitude during right leg motion, and right EO and right IO amplitude during left leg motion. No significant differences (p < 0.10) were detected between the LBP and Control groups in the pelvic motion patterns exhibited. For the muscle variables, higher activation levels were demonstrated by the LBP group. The final stage of the LRA produced a statistically significant prediction model that correctly classified 88% of the Control group and 86.7% of the LBP group. Study 3: Statistically significant differences (p < 0.10) were detected between the PHE Test and hip extension phase of gait in the sagittal plane lumbo-pelvic ranges of motion (ROMs) of both groups. Statistically significant differences (p < 0.10) were detected between the ASLR Test and the hip flexion phase of gait in the frontal plane pelvic ROMs and the sagittal plane pelvic position adopted in the LBP group, but not in the Control group. Although transverse plane ROMs were not significantly different, the direction of motion between the two tasks was opposite in both groups. Conclusions: Studies 1 & 2: During the PHE Test, LBP sufferers do not generally exhibit significantly different lumbo-pelvic movement patterns during the PHE Test, but do exhibit higher GM and HAM activation levels. During the ASLR Test, LBP sufferers do not generally exhibit significantly different pelvic movement patterns, but do exhibit higher RA, EO, and IO activation levels. Assessing the movement or muscle activation patterns as traditionally described during the performance of the tests does not provide clinically meaningful information regarding motor control impairments associated with LBP. However, LBP sufferers appear to exhibit bracing and asymmetrical activation patterns that may be a result of side-dominance. Study 3: There are significant differences in the lumbo-pelvic movement strategies adopted during the PHE Test compared to the hip extension phase of gait, particularly in the transverse plane. The pelvic position adopted during the ASLR Test is significantly different from that of the hip flexion phase of gait; while transverse plane ROMs are similar between the two tasks, the direction of motion is opposite. The motor control strategies used during the tests appear to be quite different than those used during gait, and any inferences regarding the motor control strategies used during gait based on those used during either test are unlikely to be accurate. Student yes

With more and more people using roadways the need for fast and efficient repair work is becoming increasingly important. Lane closures impede traffic flow and result in congestion. To further limit the amount of time lane closures are needed for repair work, calcium sulfoaluminate (CSA) cement concrete has become an increasing popular construction material for its ability to reach adequate strength requirements within four hours. Because of this accelerated repair time, advanced testing methods are needed to verify that the replaced concrete does indeed meet or exceed the minimum compressive strength requirements. The maturity method is one test used to determine if the replaced concrete has met the minimum compressive strength requirements. However, limited research has been done on the effectiveness of the maturity method on rapid-setting CSA concretes. The current work provides a description of an experiment conducted on three different CSA concrete mixtures at four different ambient temperatures. Maturity index curves are generated based on three different types of reference concrete cylinders. Estimated compressive strength of replica concrete pavement repair slabs are compared based on each curve generated by the reference cylinders. The maturity curves generated for each mixture are then evaluated at each ambient temperature to identify limitations of the maturity method. It is concluded that later age (after seven days) maturity index values inaccurately predict the strength of the concrete mixture. It was also determined that special precautions should be in place if CSA concretes are placed at temperatures below 40 °F. Additionally, the total volume of the CSA concrete placed plays a large role in the maturity rate of the CSA.

Membrane-based Energy Recovery Ventilators (ERV) have become an important part of modern ventilation systems for commercial and residential buildings due to their high sensible and latent effectiveness. Using ERVs in winter conditions, however, can result in condensation and frost formation. Whereas frost formation requires extremely low temperatures, condensation can occur even in mild winter weather conditions. In this study, a widely used ERV is experimentally tested under various indoor and outdoor operating conditions. Short time tests are used to determine the onset of condensation while long time tests are used to investigate the effect of channel blockage due to condensation on pressure drop and effectiveness of the ERV. The presence of condensation is inferred from visual observation of water in the exchanger, investigation of the sensible and latent effectiveness, and measurements of pressure drop over the exchanger. It is shown that condensation increases the sensible effectiveness of the supply side and decreases the sensible effectiveness of the exhaust side. Additionally, the latent effectiveness of both air streams increases when condensation occurs, although the increase in exhaust side latent effectiveness is more significant. Increasing the relative humidity and temperature of the indoor air increases the possibility of condensation and its rate, while increasing flowrate only increases the rate of condensation and does not affect its onset. Finally, the accumulation of water in the channels significantly increases the pressure drop in the exhaust side while it does not significantly impact the effectiveness.

We aimed to evaluate changes in thyroid gland size during the treatment of malignancies outside the head and neck with chemotherapy and/or external beam radiation. We performed a retrospective review of records of adult patients treated at our institution with external beam radiation to the chest and/or chemotherapy with taxanes, alkylating agents, and/or a topoisomerase II inhibitor. Neck and chest computed tomography (CT) images were used to calculate thyroid gland volume before and after therapy, using Vitrea(®) software or the volumetric ellipsoid method. Thirty-seven patients were included. After treatment, there was a significant reduction in thyroid gland volume of 14.0% (P < 0.01) using Vitrea and 17.1% (P < 0.05) using the volumetric ellipsoid method. Exposure to radiation or chemotherapy was not found to be associated with the degree of thyroid gland reduction, nor was the number of days between CT scans or the stage of the malignancy being treated. Finally, the degree of thyroid gland size reduction did not predict mortality. Our results showed that the treatment of malignancies outside the head and neck with chemotherapy and/or external beam radiation results in a reduction in thyroid gland size. The impact on thyroid gland function remains unknown.

Additional file 1. PRISMA-P Checklist

Inflammation of the bovine uterus in the post-partum period is common. However, a proportion of cows fail to resolve this inflammation by 21 days post-partum (DPP), resulting in cows presenting with purulent vaginal discharge (PVD). PVD inhibits reproductive efficiency in dairy cows internationally however its effects on dairy cows in the Irish pasture-based grazing system are unclear. Our group previously identified that 7 DPP is an important time point in the development of uterine disease. Therefore, we hypothesise that PVD leads to sub-optimal levels of reproduction in the Irish dairy herd and that markers of inflammation at 7 DPP that can predict cows that will present with PVD at 21 DPP. To determine the effects of PVD, a total of 440 mixed-parity Holstein-Friesian dairy cows were assessed for PVD at 21 DPP by vaginal mucus scoring (VMS). Cattle were classified as healthy (VMS 0; clear or no vaginal exudate) or as having PVD (VMS 1-3; presence of purulent material in the vaginal exudate). The 305-day milk kg, milk protein kg and milk fat kg yield prior to and after disease diagnosis, services per conception and the calving-conception period (CCP) were recorded. Healthy cows and cows with PVD had similar milk component yield. Cows with PVD had an 9 day longer calving interval and a 34% higher risk of having a longer calving interval than healthy cows. Odds ratio analysis determined that cows with PVD were more likely to fail to conceive and to have lower conception rates than healthy cows. Cows were retrospectively categorised with “low” or “high” milk yield based on being above or below the median 305-day milk kg yield of the study population (6571 kg) in the lactation prior to vaginal mucus scoring. “High” yielding cows were more likely to present with PVD on 21 DPP, to have impaired fertility and a significantly longer in cows PVD than their healthy counterparts. We hypothesised that the circulating concentrations of vitamin D, a potent immunomodulator, are lower in cows with PVD at 7 DPP and are correlated with the acute phase protein alpha-1 acid glycoprotein (AGP) and metabolites ( ß-hydroxybutyrate (ßHB), NEFA and glucose). In total, concentrations of the vitamin D metabolite 25(OH)D3 in 557 mixed-parity Holstein-Friesian at pre-calving, calving, 7 DPP and 21 DPP were measured in blood samples. The only significant difference found was at 7 DPP where healthy cows had higher circulating 25(OH)D3 concentrations than cows with PVD. In high yielding cows, there were no 25(OH)D3 concentration variances between healthy cows and cows with PVD at any timepoint. The 7 DPP concentrations of AGP, ßHB, NEFA and glucose were similar between healthy cows and cows with PVD and there were no correlations between 25(OH)D3 and any marker in healthy cows or cows with PVD. These results reveal that although vitamin D did not modulate the inflammatory markers at 7 DPP, it is apparent that elevated vitamin D consumption occurs in cows with subsequent PVD at this stage. With this knowledge, we hypothesised that a single or a panel of prognostic biomarkers that can accurately predict the onset of PVD is obtainable at 7 DPP. We included the relative abundance of 5 reproductive tract bacterium that are known to be highly expressed in cows with PVD, the quantities of 37 glycoforms of Immunoglobulin G and previous markers for a total of 54 biomarkers. Accuracy was determined using receiver operative characteristic (ROC) curves. At 7 DPP, a combination of IgG glycoforms 6 and 9 could identify cows with PVD at 21 DPP (AUC=0.77). The same combination could distinguish between healthy cows and cows with PVD (AUC=0.88) with an above median 305-day milk yield in the previous lactation. Our results yielded a biomarker combination with an effective ability to identify cows at 7 DPP that will present with PVD at 21 DPP. This promising finding will have positive implications for future herd health and welfare.

Enthalpy exchangers using water vapor perm-selective membranes are used in building ventilation systems due to their small footprint, simplicity, reduced contaminant crossover, and relatively high efficiency. Moisture permeation properties of the membrane media that vary with operating air humidity and temperature lead to significant changes in the performance of an enthalpy exchanger and thus the whole ventilation system, impacting building energy efficiency. Evaluation of the actual energy savings potential of such energy recovery devices in building ventilation systems requires models that account for this variable membrane performance. A theoretical model is developed for current generation asymmetric composite membranes used in enthalpy exchangers. This model predicts the membrane permeability as a function of local values of air humidity and temperature, based on a limited number of kinetic water vapor sorption tests of the membrane material. The membrane model is coupled with a finite-difference model of the conjugate heat and mass transfer in full cross-flow enthalpy exchanger cores. The model predictions are validated against experimental data of a commercial-scale enthalpy exchanger. The model is used to predict the influence of outdoor air parameters (temperature, humidity) on an enthalpy exchanger and the predictions are compared against a baseline case that assumes constant membrane permeability. Such assumption can result in deviations in effectiveness predictions by up to 15%. Depending on the mode of operation, outdoor air relative humidity can increase or decrease the effectiveness of enthalpy exchangers by up to 12%. In contrast, outdoor air temperature appears to have only a minimal influence on effectiveness parameters.

Knowledge regarding complex radiation responses in biological systems can be enhanced using genetically amenable model organisms. In this manuscript, we reviewed the use of the nematode, Caenorhabditis elegans (C. elegans), as a model organism to investigate radiation’s biological effects. Diverse types of experiments were conducted on C. elegans, using acute and chronic exposure to different ionizing radiation types, and to assess various biological responses. These responses differed based on the type and dose of radiation and the chemical substances in which the worms were grown or maintained. A few studies compared responses to various radiation types and doses as well as other environmental exposures. Therefore, this paper focused on the effect of irradiation on C. elegans, based on the intensity of the radiation dose and the length of exposure and ways to decrease the effects of ionizing radiation. Moreover, we discussed several studies showing that dietary components such as vitamin A, polyunsaturated fatty acids, and polyphenol-rich food source may promote the resistance of C. elegans to ionizing radiation and increase their life span after irradiation.

The impact of air-side particulate fouling on the performance of membrane-based, fixed-plate energy recovery ventilators (ERVs) is investigated for both fine and coarse (0.3–10 μm) as well as ultrafine (∼0.1 μm) aerosols. Two residential size cross-flow ERV exchanger cores were fouled with ISO A3 medium test dust. It was found that coarse dust loading, equivalent to that of a few years of exposure in a heavily polluted environment, has minimal impact on the performance of ERV exchanger cores. In both cases, the sensible and latent effectiveness were actually slightly enhanced due to boundary layer thinning and additional turbulence potentially caused by the dust layer. Heavy dust loadings, in the absence of appropriate filtration upstream, may result in a fan energy penalty (∼50%) due to the added pressure drop across the exchanger cores. Samples of three different membrane transport media, extracted from commercial HVAC ERV exchanger cores, were loaded with graphite and NaCl aerosol nanoparticles. Accelerated loading experiments were conducted in a laboratory apparatus to simulate several years of fouling in the field. Initial and post-loading water vapor permeance through the membrane samples were experimentally determined for each loading to quantify the effects of fouling. The impact of relative humidity on the performance of loaded membranes was also studied by exposing membranes loaded with particles in dry air to an elevated RH of 75%, leading to surface condensation. The experiments show that the deposition of particles in dry air can only affect the membrane when the fouling is severe enough to form a cake layer on the membrane surface comparable to the thickness of the membrane. In the case of membranes loaded with hygroscopic salt particles, surface condensation at high RH values can lead to vapor permeance reductions of up to 15% well before the cake layer formation phase of fouling, whilst no permeance reduction was observed for membranes loaded with non-hygroscopic graphite particles. This indicates a net porosity reduction in the microporous substrate layer of exposed salt-loaded samples. A pore-narrowing process of the substrate layer, due to the mobilization of salt particles in aqueous form, is a potential explanation for these observations.

Distance Learning through game-based 3D virtual learning environments has promise for helping rural and other communities that have become increasingly dependent upon online learning to meet the Next Generation Science Standards. The team developing Mission HydroSci (MHS) envisions a learning product that integrates a game-based 3D VLE with a learning progressions approach to curriculum and innovative methods for teacher support and learning analytics. MHS uses an eight level game which at each level immerses students in a simulation environment for learning about water systems and then requires the student to put that knowledge into practice in a context of developing their competencies for scientific argumentation. This chapter describes the vision for MHS at the beginning of the development process funded by a grant award from the Investing in Innovation (i3) Fund of the U.S. Department of Education.

A member of the matrix metalloproteinase family, matrix metalloproteinase-2 (MMP-2, gelatinase A), has been extensively studied for its role in both normal physiology and pathological processes. Whereas most research efforts in recent years have investigated the pathologies associated with MMP-2 overactivity, the pathological mechanisms elicited by MMP-2 underactivity are less well understood. Here, we distinguish between 2 states and describe their causes: (i) MMP-2 deficiency (complete loss of MMP-2 activity) and (ii) MMP-2 insufficiency (defined as MMP-2 activity below baseline levels). Further, we review the biology of MMP-2, summarizing the current literature on MMP-2 underactivity in both mice and humans, and describe research being conducted by our lab towards improving our understanding of the pathological mechanisms elicited by MMP-2 deficiency/insufficiency. We think that this research could stimulate the discovery of new therapeutic approaches for managing pathologies associated with MMP-2 underactivity. Moreover, similar concepts could apply to other members of the matrix metalloproteinase family.

In order to operate effectively, currently commercialized fuel cell proton exchange membranes require sufficient hydration to ensure good proton transport. Hydration also ensures that membrane in the fuel cell stack will have a longer operational lifetime. In order to ensure adequate hydration in the stack, most liquid-cooled PEM fuel cell systems use external humidification. Without external humidification, the fuel cell must be operated at a lower operating temperature to ensure that the stack will not dry out. Operating the stack at lower temperature requires that the coolant loop in the system must reject a greater amount of heat, necessitating a large radiator, which increase system volume. Furthermore, operating at lower fuel cell stack temperatures leads to a significant trade-off in terms of stack power output and acceptable environmental operating ranges. Membrane humidifiers are an efficient form of external humidification that transport humidity through a membrane from the cathode exhaust to the incoming cathode supply air stream. In these humidifiers, membranes with a dense selective layer are used to transport water vapour without allowing oxygen and nitrogen to diffuse through the membrane. Since the membrane humidifier is coupled to the stack cathode exhaust and supply, in order to maintain its function, the membrane humidifier must not leak air or else reactant oxygen will bypass the stack through the humidifier. The humidifier must maintain a high level of water vapour transport and low air leakage over the lifetime of the device. In this presentation we present our work developing low-cost selective membranes for fuel cell humidification. These membranes are functional over a wide temperature range (-30 to +110°C) and have high water vapour permeance. They are resistant to contamination, relative humidity cycling, freeze-thaw cycling, oxidation, hydrolysis, and acidic conditions that are present in the cathode exhaust. This presentation will also discuss the incorporation of these flat-sheet membranes in to heat and mass exchangers (membrane humidifier cartridges). These cartridges are compact with a high membrane-to-volume ratio, high water vapour transport, and have low pressure loss. The membrane humidifiers are robust to a wide range of operating conditions. Furthermore, the design of these cartridges allows the humidifier to be manufactured at a low cost in high manufacturing volumes. Finally, this presentation will discuss membrane-based heat and mass exchanger performance at different operating conditions. A performance model will be presented which summarizes humidifier performance as a function of membrane properties, exchanger design and architecture, and fuel cell operating conditions.

Composite membranes combining a structural microporous substrate with a dense selective layer are used in various water vapor transport applications. The impact of exposure to aerosols on the water vapor permeance is investigated to develop an understanding of the potential for air pollution to degrade the membrane performance. Samples of commercial membranes were loaded with hygroscopic NaCl and non-hygroscopic graphite nanoparticles. Permeance measurements showed that the deposition of both particle types under dry loading conditions (RH 75%) and the associated surface condensation, the membrane permeance reduced by up to 16%. This permeance reduction is shown to be caused by pore narrowing, which results in increased resistance of the microporous substrate. SEM analysis of the fouled membrane surfaces confirmed a reduction in the average pore diameter of degraded samples, proportional to the fouling degree. The reversibility of the fouled membrane permeance, achieved through membrane cleaning, implies that re-crystallization of salt ions, entrained onto the edges of the substrate pores in an aqueous form, is a potential explanation for the permeance changes observed.

Frost formation in air-to-air heat/energy exchangers is a challenging problem in regions with very cold weather conditions, when energy recovery is most needed. Membrane-based energy exchangers may assist in overcoming frosting. In this paper, an experimental facility was developed to enable researchers to test air-to-air exchangers under frosting conditions. The test setup, sensors and data acquisition system, uncertainty bounds for major parameters, and experimental procedure are described. Two geometrically identical plate exchangers: one with a water vapor permeable membrane (energy exchanger), and one with an impermeable plate (heat exchanger) were tested under frosting conditions. The first step in frosting experiments is to find a reliable and cost-efficient method to detect frosting in the exchangers. Four methods were used to determine the onset of frost growth: visual inspection, change in the effectiveness (Δe), change in the pressure drop across the exchanger (Δp), and change in the outlet temperature (ΔT). The main contributions of the paper are the detailed comparison of these methods and the introduction of a new frost detection method based on temperature measurements only (ΔT method). It is concluded that the Δp and ΔT methods were more reliable and practical than the other methods for both heat and energy exchangers. The ΔT method detected frosting sooner and with lower uncertainties than the other methods. Furthermore, the ΔT method was least affected by the operating conditions. On the other hand, the ΔP method gave a better indication of the severity of frosting in the exchanger as more frost resulted in a higher pressure drop across the exchanger.

The full abstract for this thesis is available in the body of the thesis, and will be available when the embargo expires.

Ventilation systems are used to exhaust stale air and bring fresh air into sealed buildings. To maintain a comfortable indoor environment, this incoming air must be heated or cooled, which consumes energy. Consequently, membrane-based plate-type energy recovery ventilators are a component used in many energy-efficient ventilation systems. In these air-to-air energy recovery ventilator exchangers, incoming and outgoing air streams are passed over opposing sides of a membrane through which heat and moisture are transferred. This decreases the energy use of buildings by using the exhaust air to heat/cool and humidify/dehumidify the incoming air depending on the season. Ideally, membranes for these devices should have high water vapor permeation rates and be selective for water vapor over the transport of other gases and volatile organic compounds, including formaldehyde, odors, and contaminants, that may be present in the outgoing indoor air stream. Current certification and standards for contaminant crossov...

Untreated transgender men face serious negative health care outcomes. Effective medical, surgical, and mental health treatment ameliorates these risks. Although the research is not as robust as would be ideal, hormone treatment is effective and generally well tolerated with few serious medical risks. Surgeries carry serious risks; but for most transgender men, the benefits outweigh the risks. This review describes current evidence-based medical treatments for transgender men and provides an overview of surgical therapy to enable practitioners to discuss these options with their transgender male patients.

Membranes with high water vapour permeance and selectivity find many end uses including protective clothing, dehydration, and humidification. One application for water vapour transport membranes is in energy recovery ventilators (ERVs) for buildings. These devices improve building energy efficiency by transporting heat and moisture between incoming and outgoing air streams in building ventilation systems, effectively ‘recycling’ the energy used to condition the indoor air. Membranes for these devices must have high vapour permeance, and selectivity for water vapour over other gases and contaminants that may be present in the exhaust indoor air. Due to the high rates of water vapour transport required in these gas to gas devices, boundary layer and internal resistances within the membrane contribute significantly to performance. Commercially available membranes suffer from high water vapour transport resistance in the microporous substrate support layer. In this study we report the fabrication of novel impregnated electrospun nanofibrous membranes (IENM) for water vapour transport applications. Electrospun nanofibre layers are impregnated with a polyether–polyurethane solution and cured to create continuous thin impregnated fibre loaded film layers which are bound to a non-woven support layer. These membranes have high water vapour permeance and selectivity while eliminating the requirement for a microporous support layer which has high vapour transport resistance. Here we report initial studies on how controllable factors in the membrane fabrication (namely fibre loading and impregnated solution polymer solids concentration) affect structural and permeation properties of IENMs created. Membranes with adequate permeance and selectivity are demonstrated and direction for optimization is identified. We find that the nanofibre loading has a significant impact on water vapour permeability as the membrane thickness decreases. Future work will study how modifications to the geometric and structural properties of the fibres affect the membrane performance.

Naphthenic acids (NA) are components of most petroleum, including those found in the Athabasca oil sands and in some systems are considered to be persistent compounds. Their presence in the environment can pose significant problems since freshly released NAs are toxic to aquatic organisms. In this investigation gamma irradiation (GI) was used to reduce the toxicity and concentration of NAs in oil sand tailings and assess the impact on biogeochemical processes. GI reduced NA concentration by up to 97% in Oil Sands Process Water (OSPW) and 85% in fluid fine tailings (FFT). Dissolved oxygen flux was stimulated directly in the GI-treated FFT in both fresh and aged sources, while increases in hydrogen sulfide flux was restricted to the fresh FFT source material. Acute toxicity to Vibrio fischeri was immediately reduced following GI treatment of fresh OSPW. GI treatment followed by 28-day incubation reduced toxicity of aged OSPW to Vibrio fischeri.

Includes bibliographical references, Defensible space aims to provide residents with the power to control their residential environment, so that they will defend it against any threat. While the literature on defensible space is prolific, and while its principles are still being adapted for different contexts across the world, critiques of defensible space indicate that its validity for different contexts is questionable and necessitates further exploration. This paper explores how the implementation of defensible space principles in the Violence Prevention through Urban Upgrading (VPUU) safe node area of Harare, Khayelitsha has reduced crime rates and anti-social behaviour. Furthermore, it also aims to provide planners with knowledge regarding VPUU's prescription to defensible space principles. The research was conducted primarily through the use of the case study method, and a critical discourse analysis of VPUU's urban design principles. Harare's crime statistics were analysed through the use of mixed methods, in order to gain an understanding of how crime has been affected in the area. Interviews with locals from Harare provided insight on how residents perceived safety in their area after VPUU's intervention. Observations were also made in order to understand how the intervention area functions and how people use it. Cognitive mapping was done with primary school children to ascertain their perceptions of safety in Harare. The research findings revealed that the implementation of defensible space principles in Harare has improved the quality of public space, but it has not reduced crime rates or anti-social behaviour. Moreover, the main finding revealed that crime was not solely a result of design flaws, but rather as a result of the social conditions in the neighbourhood. As a result, the main recommendation was that crime prevention strategies should not focus solely on design but should address the social conditions present. The researcher argues that the implementation of defensible space principles should be context-driven, because what works in one context will not necessarily work in another.

The mammalian photoreceptor is a dynamic polarized cell, in which protein transport and translocation are continuously taking place. The ability of these cells to accurately and efficiently localize protein components is essential for survival and proper functioning. Post-biosynthesis protein transport from IS to OS and translocation of transducin from OS to IS and back again, in response to light and dark, respectively, test the transport systems in these cells. Additionally, localization of membrane-associated proteins offers a challenge, as lipidated proteins must move freely within the hydrophilic intracellular environment until reaching a destination membrane. As a result, photoreceptors are an ideal model for studying intracellular membrane-associated protein trafficking. Chapter 1 reviews photoreceptor structure and describes the need for accurate and efficient transport mechanisms in these cells. Eukaryotic prenylation and acylation are examined providing context for discussing the biosynthesis, transport, and light-induced translocation of transducin. Lastly, UNC119, which interacts with and is critical in mediating transducin's translocation, is reviewed. Chapter 2 focuses on the biochemical and structural characterization of the UNC119-transducin-α interaction. The co-crystal structure of UNC119-Lauroyl- GAGASAEEKH at 2.0Å resolution offers definitive evidence for this interaction. Wildtype and Unc119-/- mouse models in conjunction with C. elegans unc-119 mutants provide in vivo evidence that UNC119 is required for G protein trafficking in sensory neurons. These data provide the first detailed description of a specific UNC119 function offering insight into the mechanism underlying transducin light-induced translocation. Chapter 3 touches on the generation of an UNC119-Tα-GMPPNP complex, but moves away from light-induced translocation and describes the role PrBP/δ plays in postbiosynthesis transport of PDE6. A general review of PrBP/δ and PDE6 offers a basic foundation for understanding how these two proteins interact and what role this interaction plays. While efforts focused on generating protein crystals of a PrBP/δ-PDE6 complex were unsuccessful, collaboration with Ted Wensel's group yielded a cryo-EM reconstruction of the complex and its features and implications are discussed. Chapter 4 concludes this work with discussions of the aforementioned findings and future directions that might prove useful in further understanding the role UNC119 plays in G protein trafficking and how the PDE6-PrBP/δ complex assembles.

Despite advances in therapy, acquired immune deficiency syndrome (AIDS) continues to be a global problem. New therapeutic avenues are being explored, including dendritic cell (DC)-based immunotherapy. While DCs can efficiently promote an immune response, their limited lifespan within the lymph node represents an obstacle to efficient immunotherapy. ;We examined different gene transfer methods, observing lentiviral transduction to be the most effective. Transduction using generated lentiviral transfer vectors encoding M11L and EGFP were used to determine effects on cellular viability. We did not observe significant differences in viability following apoptosis induction in transduced L cells. In primary DC cultures, transduction with and without M11L did not influence DC maturation or longevity in either the short or long term, though transduction was more efficient in the immature DC population. These results demonstrate that transduction is effective for gene transfer into DCs. However, techniques for dual gene expression must be further refined.

The presence of trees is a limiting factor for wild turkeys (Meleagris gallopavo) throughout the arid and semiarid portions of their range. Any long-term changes that occur to local tree populations will likely impact local wild turkey populations. Cottonwoods (Populus spp.) are the primary riparian tree of western North America and are linked to the flow regime of the river system. From 2000 through 2006, we measured 3,832 Plains cottonwoods (P. deltoides ssp. monilifera) at four sites in the Rolling Plains of Texas and Kansas. Only 132 (3.4%) of these cottonwoods were 7 years. We used Landsat satellite imagery to identify changes, from 1973 to 2005, in riparian trees that may have occurred concurrently with changes in local wild turkey populations. Our supervised classification accuracies ranged from 0.9 to 64.0%, which were insufficient for us to complete our objectives. Landsat imagery was not sufficient to identify changes in riparian trees in our study area. Other satellite-based systems provide improved spatial resolution, but currently lack the necessary temporal resolution to be effective. We suggest aerial photography and ground-based surveys remain the most useful tools for documenting changes in riparian trees.

Research was conducted to determine the independent effects of digestible energy intake (DEi) and body weight (BW) on physical and chemical body composition in growing-finishing pigs. Fifty-six Yorkshire entire male pigs were fed one of four levels of DEi between 15 and 115 kg BW, and slaughtered at 40, 65, 90, and 115 kg BW. Between 15 and 90 kg BW, average DEi were 16.05, 20.86, 25.15, and 28.78 MJ/d, and supported gains of 502, 731, 899, and 951 g/d, respectively. Increased BW and decreased DEi were associated with decreased proportion and content of protein in the whole body. Whole body lipid content increased with DEi and BW while the contribution of visceral lipid to whole body lipid was not affected by DEi and BW. Absolute DEi alone was an adequate predictor of chemical body composition in this population of entire male pigs over the BW and DEi ranges that were evaluated.