While the spring and summer months are typically the severe weather climatological peak for the East-Central United States, severe thunderstorms and deadly regional tornado outbreaks can occur during the cool season months (e.g., October-March). In an effort to better document and improve operational forecasting of these events, this study focuses on cool season severe thunderstorms in the Ohio and Tennessee Valleys during the 1995-2002 cool seasons.Most severe thunderstorm and tornado events in the East-Central United States during the cool season are characterized by a high frequency of wind reports compared to hail and tornado reports. All severe report classes (i.e. tornadoes, hail, and wind) displayed a frequency tendency to remain high in the late evening and overnight hours. Additionally, it was found that tornado occurrence typically came in the form of a tornado outbreak. Additionally, when tornadoes did occur, they were found to be statistically more intense than tornadoes outside of the EC region during the same period. It is also concluded tornadoes favor the southern half of the region, whereas hail and wind reports tend to favor the southern two thirds of the region. In examination of cool season supercell characteristics, supercells favors a west-southwest to east-northeast mean motion around 45 mph. The relationship of only 11 percent between the distances of supercell tornado paths to tornadic supercell paths is an operationally important discovery. Knowing on average, how long a cool season supercell tornado is on the ground with respect to the parent supercell can aid operational warning decisions. / Department of Geography

Thesis (M.S.)--University of Nevada, Reno, 2007. / "August, 2007." Includes bibliographical references (leaves 143-147). Online version available on the World Wide Web.

Thesis (M.S.)--University of Missouri-Columbia, 2008. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on September 11, 2008) Includes bibliographical references.

Thesis (M.S.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 64-66). Also available on the World Wide Web.

Master of Science / Department of Kinesiology / Thomas J. Barstow / Background and Aim: The power-duration relationship accurately predicts exercise tolerance for constant power exercise performed in the severe intensity domain. At intensities above critical power (CP), the power-duration relationship establishes a hyperbolic curve. However, the prediction of exercise tolerance is currently unclear for work rates within the extreme intensity domain (durations <2min). We hypothesized that the power-duration relationship deviates from a linear 1/time relationship for WRs within the extreme intensity domain. Methods: Six men completed nine bilateral knee-extension tests on non-consecutive days and then performed 3 exercise tests in the severe intensity domain (S1-S3; T[subscript lim]>2–15min) and 4 in the extreme domain at 60%, 70%, 80%, and 90%1RM (T[subscript lim]<2min), in random order. Twitch force (Q[subscript tw]), maximal voluntary contraction (MVC), and voluntary activation (VA) were measured on the right vastus lateralis before and after <80s) each test; EMG was measured on the right vastus lateralis throughout each test. T[subscript lim] were plotted as a function of 1/Time. T[subscript lim] for the extreme intensities were compared to the predicted T[subscript lim] of the slope of the S1-S3 regression. Results: The r² for the severe domain 1/time model was 0.99 ± 0.007. T[subscript lim] for exercise at 60%1RM was not different than the predicted T¬lim, however, T¬lim for exercise at 70–90%1RM was shorter than the predicted T[subscript lim] (p<0.05). Post hoc analysis of the extreme domain (70–90%1RM) revealed a significant linear relationship, suggesting a W’ within the extreme domain (W’ext). T[subscript lim] of exercise at 60% 1RM was not different from the predicted value of the 1/Time relationship of the extreme domain. Q[subscript tw] and MVC were significantly decreased following exercise at S1-S3 and 60% 1RM, while no changes existed in Q[subscript tw] or MVC following exercise at 80 and 90%1RM. Further, no changes were found in VA following any exercise intensity. Conclusion: These data suggest that exercise tolerance in the extreme domain is limited by different factors than in the severe domain. However, there is a separate but measurable W’ext. Further, the factors limiting exercise in the extreme domain must be those from can be recovered by the time post-exercise measurements were made.

Oxide dispersion strengthened (ODS) alloys are known for their desirable mechanical properties and unique microstructures. These alloys are characterized by an even dispersion of oxide phase throughout a metallic matrix, and exhibit high strength and enhanced creep properties at elevated temperatures. This makes them ideal candidate materials for use in many structural applications, such as coal-fired power plants or in next generation nuclear reactors. Currently most often produced by mechanical alloying, a powder metallurgy based process that utilizes high energy ball milling, these alloys are difficult and costly to produce. One proposed method for forming ODS alloys without high-energy ball milling is to internally oxidize a bulk alloy before subjecting it to severe plastic deformation to induce an even oxide distribution. This work examines such a processing scheme with a focus on the internal oxidation behavior. Internal oxidation has been shown to occur orders of magnitude faster than expected in multi-phase alloys where a highly reactive oxidizable solute has negligible solubility and diffusivity in other, more-noble, phases. Commonly referred to as in situ oxidation, this accelerated oxidation process has potential for use in a processing scheme for ODS alloys. While in situ oxidation has been observed in many different alloy systems, a comprehensive study of alloy composition and microstructure has not been performed to describe the unusual oxidation rates. This work used Fe-Y binary alloys as model system to study effects of composition and microstructure. These alloys have been shown to exhibit in situ oxidation, and additionally, Y is typically introduced during mechanical alloying to form Y-rich oxides in Fe-based ODS alloys. Alloys with Y content between 1.5 and 15 wt% were prepared using a laboratory scale arc-melting furnace. These alloys were two phase mixtures of Fe and Fe17Y2. First, samples were oxidized between 600 and 800 °C for 2 to 72 hours, using a Rhines pack to maintain low oxygen partial pressures so that in situ oxidation could occur. Oxidation rates were accelerated when compared to traditional theory, and were not well described by a single parabolic rate constant throughout the duration of the experiment. While results agreed with Wagner theory that increased Y content should lead to decreased oxidation rates, this was attributed to a depletion of oxygen supply from the Rhines pack over time. Samples were also subjected to plastic deformation to observe how changes in microstructure influenced kinetics. Connectivity of the oxidizable phase was found to be critical to promoting the fastest rates of oxidation. Oxidation studies where then carried out using thermogravimetric analysis. A gaseous mixture of Ar-H2 was passed through a dew point control unit to vary oxidant partial pressure between 10-25 and 10-20 atm. Flow rate of the gas parallel to the sample surface was also altered. Canonical correlation analysis was then used to analyze and simplify the relationships between input and output variables. This analysis pointed to the importance of quantifying the relationship between the size of formed oxides and changes in oxidation kinetics over time. Where sustained parabolic kinetics were observed, oxides were small throughout the depth of internal oxidation. The effects of oxide size on penetration depth were then numerically modeled and incorporated into existing oxidation theory to show that the observed kinetics could be qualitatively described. After oxidation experiments, severe plastic deformation was applied to both oxidized and unoxidized microstructures using equal channel angular pressing. By manipulating pressing temperature and the number of passes, microstructures were altered to varying degrees of success. No oxide refinement was observed, but increasing temperatures and number of passes allowed for even dispersion of both oxides and Fe17Y2 intermetallic.

Indiana University-Purdue University Indianapolis (IUPUI) / Severe malaria, primarily caused by Plasmodium falciparum infection, is among the leading causes of childhood mortality globally. A key virulence factor and source of antigenic variation and immune evasion during infection is P. falciparum erythrocyte membrane protein 1 (PfEMP1). Encoded for by approximately 60 var genes, this complex protein mediates cytoadherence of infected erythrocytes to the host endothelium and is a prominent immune target for the anti-malarial immune response in children. During severe malaria, specific domains of PfEMP1 that bind to endothelial protein C receptor (EPCR) and intercellular adhesion molecule-1 (ICAM-1) on host endothelial cells, are more prevalently expressed. The interaction of these proteins and infected erythrocytes mediates the sequestration of infected erythrocytes and plays a role in severe malaria pathogenesis. Antibodies to these domains develop over time with exposure to the parasite and are thought to contribute to immunity against severe malaria in children. In this study, whole blood samples from children with different forms of severe malaria, enrolled in two observational prospective cohort studies were used to quantify the expression of PfEMP1 domains using RT-qPCR and to measure the antibody response to PfEMP1 domains via a bead-based multiplex immunoassay. Using these samples, we demonstrated that although the expression of var transcripts encoding PfEMP1 domains was generally similar across children with different forms of severe malaria, the expression of variants encoding specific EPCR-binding domains was associated with thrombocytopenia and severe anemia. The antibody response to PfEMP1 domains in children with severe malaria was highest in children with SMA and children with asymptomatic parasitemia, but not associated with decreased risk of additional malaria episodes. Overall, the results of this study suggest that PfEMP1 is acting similarly across different forms of severe malaria but that it can be related to pathogenesis and severe malaria immunity.

Background and aims: Hypertension is a public health problem and a major reason for hospitalisation and death. In Mozambique, low levels of detection, treatment and control have been described. However, data on target-organ damage and associated clinical conditions is lacking. We therefore aimed at characterising the clinical profile of patients with severe hypertension, describing the pattern of target organ damage and determining the outcomes at 6-month follow-up. Methods: We designed a prospective descriptive cohort study to assess adult patients with severe hypertension defined according to the Joint National Committee VII guidelines. The study was conducted from July 2015 to May 2017 at Mavalane General Hospital in Maputo-Mozambique. Patients were characterized through physical examination, laboratory profile, electrocardiography, and echocardiography, and followed for six months to assess occurrence of complications such as hypertensive heart failure, stroke, renal failure, hospital admission and death. Data were analysed using SPSS software version 20.0. The study was approved by the National Bioethics Committee for Health of Mozambique. Results: We studied 116 subjects (111 [95.7%] black; women 81 [70%]). Women were slightly younger than men (mean 57 years vs 59 years); 18 (15.5%) patients were younger than 44 years. The risk profile of the studied population included obesity (46; 42.5%); dyslipidaemia (59; 54.1%); diabetes (10; 8.6%) and smoking (8; 6.9%). At baseline, mean values for systolic and diastolic blood pressure were 192.3 ± 23.6 and 104.2 ± 15.2, respectively. The most frequent target-organ damage were left atrial enlargement in 91 (88.3%) with atrial fibrillation in 9 (7.9%); left ventricular hypertrophy in 57 (50.4%); hypertensive retinopathy in 30 (26. 3%) and renal damage in 29 (25.7%) subjects. Major events during 6-month follow-up were hospitalisations (12; 10.3%) and death (10; 8.6%). Renal damage (4; 4.2%), stroke (4; 3.4%) and heart failure (2; 1.7%) were the most common complications occurring over the follow up period. Conclusion: Severe and complicated hypertension affects young people with higher incidence of obesity, diabetes and smoking than that found in general population. High occurrence of target organ damage is found at baseline, particularly heart damage, renal lesion and stroke. On follow up, severe hypertension is associated with high number of hospitalisations and high case-fatality rate. Moreover, renal damage, stroke and hypertensive heart disease were common complications on follow up. Further research is needed to understand the determinants of these poor outcomes.

Background: Severe mental illnesses (SMI) cause significant impairment for those living with the illnesses and often rely on caregivers for the ongoing care. Available evidence suggests that individuals responsible for caregiving may get distressed due to the caregiving experience, a phenomenon researchers call caregiver burden. Following the shift to community-centered mental health services, several studies on caregiving burden have been conducted in high income countries (HIC). However, there remains scarcity of data on the subject in SubSaharan Africa including Malawi. Therefore, the present study investigated the prevalence and associated factors of caregiving burden among caregivers of individuals with SMI at St John of God Hospitaller Services (SJOGHS) in Mzuzu-Malawi. Methods: The study adopted a hospital based cross sectional study. Recruitment took place at two outpatient departments of SJOGHS. Informal caregivers who were 18 years and above were asked to participate. The study recruited 139 caregivers and two research assistants approached participants at the waiting area. Caregivers who gave consent were asked questions about their caregiving activities using the Zarit Burden Interview (ZBI) (maximum score, 88). Data analysis was done using frequency distributions and descriptive statistics. The study used non-parametric tests such as a chi-square on all categorical measurements to test associations between variables and parametric tests such as t test on all continuous variables. The unadjusted and adjusted associations between socio-demographic factors and caregiving burden was conducted using logistic regression models. Results: On average, most caregivers experienced mild to moderate caregiving burden on the ZBI score (31.5 ± 16.7). In the adjusted model after controlling for caregivers’ gender, caregivers’ age, level of education, social support, care recipients’ age and care recipients’ gender, only caregivers’ age, social support and care recipients’ age remained significantly associated with caregiving burden. Older caregivers were more likely to experience caregiving burden than younger caregivers (OR=1.03, 95% CI 1.00-1.06), caregivers with social support were 71 % less likely to develop caregiving burden than those without social support (OR=0.29, 95% CI 0.14-0.62) and caregivers of older care recipients were less likely to experience caregiving burden than those of younger care recipients (OR=0.26, 95% CI 0.11-0.64). v Conclusion: Even though the caregiving burden found in this study was low compared to other previous studies in some arguably developed countries such as Iran and Turkey, it remains high in other developing countries such as Ghana and Nigeria. The low burden in this study, could be attributed to several factors and context in which the study was conducted. One such factor is the routine psychoeducation that the hospital often conducts for caregivers during the subsequent monthly reviews of their care recipients. An important follow up would be to investigate caregiving burden among caregivers who are unable to access the services at SJOGHS. The results of this study are important to guide policy in the formation of effective community programs that may assist mitigate the burden of informal caregivers. Finally, to understand the importance and implications of informal caregiving, further studies are needed in Malawi.

The objective of this work was to evaluate the efficacy of an induced normothermia protocol by comparing patient mortality and outcomes in patients treated at Boston Medical Center (BMC) before and after the implementation of the protocol. The controls (regular fever management) and the cases (induced normothermia) were demographically similar, except there were more whites (p = 0.01) in the control group and more of the patients in the control group were transferred to BMC from outside hospitals (p = 0.006), although there was not a higher incidence of death among patients who were transferred from outside hospitals (p = 0.55). The patients in the case group were kept normothermic throughout the first 7 days of their hospital stay more effectively than those in the control group (p = 0.0001). Average intracranial pressure (ICP) and cerebral perfusion pressure (CPP) were not different between the two groups, although mean arterial pressure (MAP) was (p = 0.84; p = 0.08; p = 0.02, respectively). Mortality was lower in the case group by hospital discharge (p = 0.007) and patients in the case group were more likely to achieve a positive functional outcome (p = 0.03). In light of these findings, there is a need for high-quality prospective trials to assess the efficacy of induced normothermia compared to regular fever management.