In situations of mass disaster (1), which include airline crashes (2), terrorist attacks (2), large fires (3), and mass homicide (4), the human remains are often damaged beyond recognition (5). In these cases, bones and teeth are potentially the only acceptable source of deoxyribonucleic acid, or DNA (6). Previous studies have evaluated a plethora of techniques to purify DNA from hard tissue, but there is no consensus on the optimal process by which to extract and purify DNA from these samples. Not only are hard tissue samples difficult to process, in many cases the samples are subjected to extreme environmental conditions, such as high temperature. Thus, there is interest in obtaining information on DNA quality from samples exposed to high temperatures (7). This work hopes to fill the gap by: 1) optimizing a DNA extraction protocol from hard tissue; and 2) measuring the degree to which the DNA is degraded in an effort to link the quantity and quality of the DNA recovered to the outer appearance of the tooth. To accomplish this, individual teeth were burned in a furnace at 100 °C, 200 °C, 300 °C, 400 °C, 500 °C, and 600 °C for 10, 20, and 30 minutes. The optimal extraction procedure utilized Amicon® Ultra-4 Centrifugal 30K filter devices and the QIAGEN MinElute Polymerase Chain Reaction (PCR) Purification Kit. Samples were quantified using the Quantifiler® Trio quantification kit to obtain the quantity and quality metrics. After heat exposure, each tooth was photographed and subsequently given a color designation or value: light yellow to beige teeth were assigned a value of 1; dark yellow to orange were assigned a value of 2; brown was assigned a value of 3; shiny black was assigned a value of 4; and black to light gray teeth were assigned a value of 5. Both carbonization and the early stages of calcination were observed. The mass of DNA per mass of tooth was determined by examining quantitative PCR (qPCR) results for both a large and small autosomal fragment. The degradation index, or DI, was also calculated from qPCR measurements. The results demonstrate a strong correlation between the quantity of DNA recovered, the quality of the DNA obtained, and the designated color value. The highest recovery rates were obtained from teeth assigned a color value of 1 (unaltered beige) or 2 (yellow to orange). These teeth were exposed to either room temperature, 100 °C or 200 °C. At temperatures exceeding 300 °C, the amount of DNA recovered drastically decreased and was inconsistent. Some of the samples subjected to temperatures at and above 300 °C resulted in no quantifiable DNA. In contrast, the DI results suggested that when the teeth were subjected to temperatures ≤ 100 °C, the quality of the DNA was good, wherein the DI value was approximately 1. At 200 °C, the temperature began to impact the DI value, which increased with time to the point where a DI was no longer able to be calculated because the large autosomal fragment could not be detected. In conclusion, the current work compares five different methods of DNA extraction to establish a best practice extraction procedure for these difficult samples. Furthermore, this work suggests that examination of the tooth’s appearance can be used to deduce whether successful DNA recovery is likely. In summary, the results demonstrate that when the tooth sample was assigned a color value of 1, the quantity and quality of the DNA obtained was high. Once the color value of the sample rose to 2, the quantity and quality of DNA varied greatly and the probative value of the sample was diminished. Samples that exhibited large color changes or had begun the calcination process resulted in no recoverable DNA.

Cardiovascular disease is the leading cause of death in the developed world. The majority of cardiovascular diseases are characterized by disorders of the arteries, predominantly caused by endothelial dysfunction and arterial stiffening. Passive heat stress results in elevations in core temperature (inducing heat shock protein expression) and changes in cardiovascular hemodynamics, such as increased cardiac output and shear stress, that are similar to exercise. Thus, repeated passive heat stress (“heat therapy”) may provide an alternative means of improving cardiovascular health, particularly for patients with limited exercise tolerance and/or capabilities. Therefore, the goal of this dissertation was to perform integrative studies to determine the effects of heat therapy on vascular function and the associated cellular pathways in young, sedentary humans. Twenty subjects were assigned to participate in 8 weeks (4-5x/week) of heat therapy (N=10; immersion in a 40.5°C bath sufficient to maintain rectal temperature ≥38.5°C for 60 min/session) or thermoneutral water immersion (N=10; sham). As discussed in Chapter V, we found that heat therapy improved numerous well-established biomarkers of conduit vessel/macrovascular function, including flow-mediated dilation (a measure of endothelial function), arterial stiffness, intima media thickness, and blood pressure. Heat therapy also improved microvascular function, as discussed in Chapter VI, measured as improved cutaneous thermal hyperemia and nitric oxide-dependent dilation (the difference between microdialysis sites receiving Lactated Ringer’s [control] and nitric oxide synthase inhibition). No changes were observed in any variables in sham subjects. In Chapter VII, we showed that both direct cellular heating and serum collected from human subjects following heat therapy improved nitric oxide bioavailability and angiogenesis in cultured endothelial cells, providing potential mechanisms by which heat therapy improves vascular function in vivo. Therefore, the studies described herein provide comprehensive evidence that passive heat therapy improves vascular health and insight into the mechanisms involved. Our data presented in Chapters IV-VII, combined with pilot data we conducted in spinal cord injured individuals (Chapter VIII), strongly indicate that passive heat therapy could be used as a simple and effective tool to improve cardiovascular health in a variety of patient populations. This dissertation includes published and unpublished co-authored material.

THESIS ABSTRACT This thesis work was undertaken to investigate the effects of internal (i.e. morphology, physiological capacity, stress and inflammatory cytokines) and external (i.e. heat exposure) factors on military physical performance in members of the Canadian Armed Forces (CAF). By gaining insight into how these factors affect military physical performance, training and intervention strategies could be better tailored for optimizing performance. Both morphology and physiological capacity have previously been recognized to affect performance on certain military physical performance tasks. However, the effect of such factors on the newly implemented Common Military Task Fitness Evaluation (CMTFE), the current physical employment standard for the CAF, has not been determined. Stress and inflammatory cytokines have also been shown to affect physical performance in the general population, but there is no data available on levels of stress and inflammatory cytokines in the CAF, or their potential effect on military physical performance. Recently, the CAF have also implemented a loaded march, followed by an assessment of military physical performance (FORCEcombat), as a part of the physical performance testing for all members of the Canadian Army. However, there is a lack of research currently available on how factors like heat exposure can affect thermoregulatory and cardiovascular response, as well as performance on a loaded march, and the following FORCEcombat test. In order to provide key information about the requirements and delivery of the military physical performance tests currently used in the CAF, my thesis focused on four main parts to better understand the importance of some of the internal and external factors known to affect physical performance. Firstly, my thesis assessed CAF members’ morphological and physiological characteristics that may affect overall performance on the CMTFE. In Chapter 2, results showed that both characteristics of morphology and physiological capacity separated the top and bottom performers. Even though a difference in morphology was observed between top and bottom performers, performance on the CMTFE was mainly dependent on aerobic capacity and measures of strength, rather than morphology. Aerobic capacity explained ~36% of variability in performance among women, and ~32% variability in performance among men. Core strength also had a significant effect on performance in both groups, however, men relied more on upper body strength than did women. Apart from showing that physiological capacity, rather than morphology was the main component affecting performance outcome on the CMTFE, it was also concluded that, unlike physical performance tests used by the U.S. Armed Forces (i.e. push-ups, sit-ups, mile run), no body mass bias exists against larger individuals performing the CMTFE. Chapter 3 and 4 focused on describing levels of stress and inflammatory cytokines among CAF members, and their effect on military physical performance. Stress exposure is known to induce an increase in the production of stress and inflammatory cytokines, and an increase in levels of inflammatory cytokines have been shown to be associated with a decrease in physical performance in general population. Members of the armed forces are susceptible to high stress exposure, but no current data exist on basal levels of stress and inflammatory cytokines in a military population. We therefore performed a descriptive analysis of levels of stress and inflammatory cytokines among CAF members. The results from this analysis showed a generally low detection rate of most of the inflammatory cytokines measured in our military population. However, we did observe a higher detection rate for IFN-γ, TNF-α, IL-2, IL-5, IL-8, IL-17a, IL-23 and IL-31 with increasing age. Adiponectin levels were higher in women compared to men (5.81 (3.52-13.19) µg/ml vs 16.71 (7.68-25.32) µg/ml), whereas IL-18 levels were higher in men compared to women (89.25 (84.03-94.48) vs 75.91 (69.70-82.13) pg/ml). Increasing age was associated with higher basal levels of C-Reactive Protein (CRP), Adiponectin, IL-18 and IL-2, and we also found a significant positive correlation between body fat percentage (BF%) and CRP levels. Following the outcomes of the descriptive study, the associations between levels of stress and inflammatory cytokines and military physical performance were elucidated. Using multiple linear regression, controlling for covariates such as age, sex and BF%, a significant negative association was observed between CRP levels and Total Performance on the CMTFE (p=0.01), picking and digging performance (p=0.04), aerobic capacity (p=0.05) and plank time (p<0.01) among CAF members. Finally, in Chapter 5, the effect of heat exposure on the capacity to perform a task oriented military test was quantified. Many CAF members are subject to a significant heat exposure on a daily basis, and studies from the general population have shown that heat exposure can have a detrimental effect on physical performance. As mentioned previously, The Canadian Army have recently implemented a test of loaded march performance, as a part of their occupational physical performance testing. The loaded march will be performed while wearing military personal protective equipment (PPE) and a daypack (~35 kg), and all members of the Canadian Army will be required to perform this test. Due to this need for mass testing, a large part of the loaded march performance assessments will be required to take place during the summer months. Temperature and relative humidity (RH) can reach high levels on several of the Canadian Army bases located around Canada, during the summer months. However, there is currently limited research available assessing the thermoregulatory and cardiovascular responses to performing a loaded march in the heat while wearing military PPE. Consequently, a study was designed to determine the thermoregulatory and cardiovascular responses to a loaded march (60 min, 5.17 km*h-1, ~35 kg external load) at normal temperature (21°C, 50% RH) and in the heat (30°C, 50% RH). This study also aimed to quantify the effect of heat exposure and previous experience on loaded march and military physical performance (FORCEcombat). Ten participants experienced with loaded march (military reservists), and ten participants inexperienced with loaded march (civilians) were recruited for this study. The results showed that whereas nine out of ten participants in the experienced group completed the loaded march in the heat, only five of the ten participants in the inexperienced group were able to do the same. Performing the loaded march in the heat while wearing military PPE led to a state of uncompensable heat stress, for both the experienced and the inexperienced group. Both groups showed a continuous increase in core temperature and heat storage (0.025°C/min and 0.02°C/min mean increase in core temp, 8.7 kj/min and 6.7 kj/min mean increase in heat storage, for the inexperienced and experienced group respectively) throughout the heat trial. Apart from the difference in completion rate on the loaded march, experienced participants also had a lower heart rate (134.2±11.9 vs 143.1±8.9 bpm, p≤0.05), perceived exertion (10.2±1.4 vs 13.0±0.9, p≤0.05), thermal comfort (1.9±0.5 vs 2.4±0.4, p≤0.05), and FORCEcombat completion time (662±133 vs 530±49 sec, p≤0.05) compared to the inexperienced participants. The overall results from this thesis show that physiological capacity, inflammatory cytokines, heat exposure and previous experience, all have an effect on military physical performance. It was found that physiological capacity rather than morphology, was the superior predictor of performance on the CMTFE: inflammatory cytokines are present in CAF members and CRP levels increased with increasing age, CRP levels were negatively associated with military physical performance, performing a loaded march in the heat while wearing military PPE exposed both experienced and inexperienced participants to a state of uncompensable heat stress and decreased performance on the FORCEcombat test, and that previous experience has a positive effect on loaded march completion rate and FORCEcombat performance.

No description available.

Heat stress is influenced by environmental conditions, workload and clothing. A critical environment is the upper limit of compensable heat stress for a given metabolic rate and clothing ensemble. The physiological strains associated with heat stress are core and skin temperatures, heart rate and physiological strain index (PSI). Because heat dissipation mechanisms may differ between men and women, there may be gender differences in the critical environment and the associated physiological variables. Gender differences were explored between acclimated men (n = 20) and women (n = 9) at the upper limit of compensable heat stress. Participants walked on a motorized treadmill at a target metabolic rate of 160W/m2 while wearing five different clothing ensembles (cotton work clothes, cotton coveralls, and three coveralls of particle barrier, liquid barrier, and vapor barrier properties). The starting air temperature (Tdb) was 34°C and humidity was held constant at 50%. Once thermal equilibrium was achieved, Tdb was increased 1°C every five minutes until loss of thermal equilibrium or termination criteria were met. Upon initial analysis, several gender differences were found. A significant difference (p = 0.035) was found for WBGTcrit, where values were 32.5°C for men and 33.1°C for women. Women had higher average heart rates (hr = 125 and 112 bpm), average skin temperatures (Tsk =36.4 and 36.2°C), and psi values (4.5 and 3.8) than men. No significant difference was found between genders for core temperature (tre) (p = 0.147). The target metabolic rate of 160W/m2 was not achieved and there were significant differences (p <0.0001) between men (172 W/m2) and women (152 W/m2). The effects of metabolic rate on WBGTcrit was examined and it was discovered that the difference in WGBTcrit could be explained by the difference in metabolic rate. The same logic was applied to the physiological responses and confirmed a difference between genders for Tre, HR, and PSI. The differences for Tsk disappeared. These findings indicate that women experienced a greater cardiovascular strain at the critical conditon and also greater heat strain than men at the same heat load.

No description available.

This thesis consists of three essays in applied microeconomics: First, heat and school absence: evidence from a survey of Indian children. Second, heatwaves and short-term morbidity in India. Third, intra-family marriage and pregnancy outcomes. Chapter 1. India is the second most populous country on earth with young people representing a significant number of the population resulting in data that indicates such figures at 38 per cent. With such high numbers, major consideration must be given into developing informed and targeted policies to ensure positive educational outcomes for young people. This paper contributes to existing literature by investigating the impact of high temperatures on students’ rates of absenteeism, relying on the short-term exogenous variation in daily maximum temperatures. The paper highlights the heterogeneity of the effect of temperature by climate zone. To create data, we link information on children’s school absences from the India Human Development Survey (IHDS-II) in combination with meteorological data from the ERA-Interim archive taken from a thirty day period prior to individual interview dates. Our findings suggest that high temperatures have a substantial negative impact on students’ attendance in rural areas. However, limited evidence of such an effect is found in urban areas. Our results therefore indicate a need to implement future in-depth studies. Chapter 2. Within this chapter, we investigate the impact of prolonged heat exposure on individuals short-term morbidity rates over a thirty day period prior to the interview date. We work with a broad dataset and use an econometric model that utilizes plausibly exogenous variation in high weather temperatures. We implement the percentile-based approach and three different heatwave metrics as a innovative way of defining and capturing the impact of heatwaves on health outcomes. Our results show that heatwave intensity of the eighty-fifth percentile over the duration of three consecutive days of extensive heat has a significant adverse effect on individuals short-term morbidity. More so, our findings indicate a disparity between genders in relation to the impact of heatwaves. Finally, it can be suggested that individuals having to travel an extensive distance in order to access water are most affected by high temperatures. Chapter 3. Millions of people worldwide are married to their blood relatives, yet the resulting impact on offspring health continues to be debated. Within this paper, we provide evidence around this debate by studying the birth outcomes from a large, representative sample of Indian women in varying marital circumstances. We explore the impact of intra-family marriage on negative pregnancy outcomes including stillbirth, miscarriage, and child death after birth. We utilize an ordinary least squares model (OLS), which controls for a wide range of financial and family factors. The results show that being a woman related to her husband by blood increases the probability of experiencing negative pregnancy outcomes by 2.8 percentage points. Our finding is robust using the instrumental variable approach (IV). The instrumental variable represents the ambient level of violence against women, which positively affects the probability of consanguineous marriage. The IV approach leads to a slightly smaller adverse impact of 2.2 percentage points. In addition, the OLS results provide suggestive evidence that intra-family marriage has no heterogeneous impact across religion types.

Heat-related illnesses and deaths are significant public health problems. Extreme heat is the No.1 deadliest form of weather on average in 1990-2019 in the US according to the National Weather Service. Measurements and forecasts made at regional weather stations are a common data source of Heatwave Early Warning Systems. However, regional weather stations provide inaccurate estimates of the heat index that people experience in different microclimates. Introducing a direct measurement of heat index experienced by individuals via wearable sensors will allow more accurate exposure assessment and identification of factors associated with dangerous exposures to extreme heat. The goal of this dissertation is to characterize the individually experienced heat index exposure via wearable sensors in an urban and a rural location in summer in a southern part of the United States. In the first study, 51 outdoor workers in Birmingham, Alabama wore a small thermometer attached to their shoe. Their occupational Wet Bulb Globe Temperatures (WBGT), a comprehensive heat exposure index, was estimated from either temperature from the shoe thermometers or nearby weather stations. In the second and third studies, 88 urban participants and 89 rural participants completed a seven-day intervention where they performed normal activity on Days 1-2 and spent an additional 30 minutes outdoors daily on Days 3-7. Participants wore a small thermometer attached to the shoe and a pedometer at their waist to track steps. Neighborhood hygrometers/thermometers were deployed close to participants' homes to measure neighborhood level heat indexes. In the fourth study, we conducted a phone survey including 101 participants in the same urban and rural locations to examine how their heat-health behaviors changed due to COVID-19 and high profiles of police brutality cases in Summer 2020 compared to previous summers. The results demonstrated that (1) a wearable thermometer on the shoe was a feasible way to measure individually experienced temperatures; (2) among outdoor workers, WBGT from shoe thermometer temperatures estimated more hours in dangerous exposure categories and recommended more protective work-rest schedules compared to WBGT from weather station temperatures; (3) neighborhood level heat indexes improved the prediction of individually experienced heat indexes compared to weather station data alone; (4) rural participants experienced higher heat index exposures than urban participants, after accounting for ambient conditions; (5) spending a small amount of additional time outdoors was a feasible and effective intervention where participants walked more steps and had lower individually experienced heat indexes during the intervention days compared to baseline days; (6) a significantly lower percent of participants reported they would use public cooling centers in Summer 2020 compared to previous summers. Taken together, the results of these studies identified methods for more accurate heat exposure assessment and its application in monitoring heat-safety while promoting physical activity via time spent outdoors in the summer. Future work could incorporate physiological response monitoring linked to simultaneous individually experienced heat exposure to further characterize exposure-response relationships across different populations. Additionally, a longer intervention and more advanced wearable devices such Fitbit, Apple Watches could be used to monitor sustainability of the intervention and intervention benefits beyond short term increases in physical activity, respectively. / Doctor of Philosophy / Extreme high temperatures/humidity can bring dangerous adverse effects in people. Extreme heat is on average the deadliest form of weather in 1990-2019 in the US estimated by National Weather Service. Heatwave Early Warning Systems are introduced to closely monitor extreme heat events, estimate the magnitude of health consequences due to extreme heat, send warning messages to vulnerable populations, and trigger response plans to reduce the dangerous health effects of heat. Heatwave Early Warning Systems generally rely on the measurement and forecasts from regional weather stations. However, the temperature/humidity measurements made at weather stations can be different from the temperature/humidity people experience. People can live far away from weather stations and they move through indoor and outdoor locations, where weather station measurements will not represent temperatures experienced, particularly in climate-controlled indoor settings. Therefore, we recruited participants in an urban and a rural location and had each participant wear a small thermometer clipped to their shoe to directly measure the temperature they experienced as they went about their normal activities. In the first study, 51 outdoor workers wore this small thermometer on their shoe at work. We calculated a comprehensive heat exposure index from either the shoe thermometer temperatures or nearby weather station temperatures. In the second and third studies, 88 urban participants and 89 rural participants completed a seven-day intervention where they performed normal activities on Days 1-2 and spent an additional 30 minutes outdoors daily on Days 3-7. Participants wore the small thermometer clipped to the shoe and a pedometer at their waist to track how many steps they walked. We placed temperature/humidity sensors close to participants' homes to take measurements at a neighborhood level. In the fourth study, we conducted a phone survey including 101 participants in the same urban and rural locations to examine whether they had different cooling methods due to the COVID-19 pandemic and high profiles of police brutality cases in Summer 2020 compared to previous summers. The results demonstrated that (1) a small thermometer clipped on the shoe was a feasible way to measure temperatures at the individual level; (3) among outdoor workers, the comprehensive heat exposure index using temperatures from the shoe thermometers estimated more hours when outdoor workers were at a risk of dangerous exposure to extreme heat, and it recommended more rest time for workers to cool off compared to using weather station temperatures alone; (3) neighborhood level temperature/humidity was more representative of the temperatures recorded from thermometers on the shoe compared to nearby weather stations; (4) rural participants experienced higher temperature/humidity than urban participants, even when their nearby weather station temperature measurements were the same; (5) spending a small amount of additional time outdoors is a feasible and effective intervention where participants walked more steps and experienced lower temperature/humidity during the intervention days compared to baseline days; (6) a smaller number of participants reported they would use public cooling centers/spaces (e.g., air-conditioned library, air-conditioned churches, waterparks) to cool down due to fear of contracting COVID-19 and safety concerns brought by the high profiles of police brutality cases in Summer 2020 compared to previous summers. Taken together, the results of these studies showed that the wearable thermometers clipped on the shoe could provide more accurate assessment of temperatures experienced by participants compared to weather stations. This method could be used in future outdoor time interventions to monitor and ensure participants safely spend time outdoors while minimizing the risk of heat-related illness. In future work, more advanced sensors (e.g., Fitbit, Apple Watch) can be worn by participants to measure physiological responses across different temperatures experienced. Additionally, a longer intervention time can be used to test if participants would continue to spend additional time outdoors.

This project was a test of concept for an external heating system for Big Area Additive Manufacturing (BAAM) Fused Deposition Modeling (FDM) 3D printers. To goal of the heating system was to prevent or mitigate delamination and warping in BAAM FDM prints by propelling warm air onto printed layers while not interfering with prior functions of the 3D printer.