The present research attempted to use display design as a means to mitigate the occurrence and severity of symptoms of motion sickness and increase performance due to reduced “general effects” in an uncoupled motion environment. Specifically, several visual display manipulations of a 360° indirect vision system were implemented during a target detection task while participants were concurrently immersed in a motion simulator that mimicked off-road terrain which was completely separate from the target detection route. Results of a multiple regression analysis determined that the Dual Banners display incorporating an artificial horizon (i.e., AH Dual Banners) and perceived attentional control significantly contributed to the outcome of total severity of motion sickness, as measured by the Simulator Sickness Questionnaire (SSQ). Altogether, 33.6% (adjusted) of the variability in Total Severity was predicted by the variables used in the model. Objective measures were assessed prior to, during and after uncoupled motion. These tests involved performance while immersed in the environment (i.e., target detection and situation awareness), as well as postural stability and cognitive and visual assessment tests (i.e., Grammatical Reasoning and Manikin) both before and after immersion. Response time to Grammatical Reasoning actually decreased after uncoupled motion. However, this was the only significant difference of all the performance measures. Assessment of subjective workload (as measured by NASA-TLX) determined that participants in Dual Banners display conditions had a significantly lower level of perceived physical demand than those with Completely Separated display designs. Further, perceived iv temporal demand was lower for participants exposed to conditions incorporating an artificial horizon. Subjective sickness (SSQ Total Severity, Nausea, Oculomotor and Disorientation) was evaluated using non-parametric tests and confirmed that the AH Dual Banners display had significantly lower Total Severity scores than the Completely Separated display with no artificial horizon (i.e., NoAH Completely Separated). Oculomotor scores were also significantly different for these two conditions, with lower scores associated with AH Dual Banners. The NoAH Completely Separated condition also had marginally higher oculomotor scores when compared to the Completely Separated display incorporating the artificial horizon (AH Completely Separated). There were no significant differences of sickness symptoms or severity (measured by self-assessment, postural stability, and cognitive and visual tests) between display designs 30- and 60-minutes post-exposure. Further, 30- and 60- minute post measures were not significantly different from baseline scores, suggesting that aftereffects were not present up to 60 minutes post-exposure. It was concluded that incorporating an artificial horizon onto the Dual Banners display will be beneficial in mitigating symptoms of motion sickness in manned ground vehicles using 360° indirect vision systems. Screening for perceived attentional control will also be advantageous in situations where selection is possible. However, caution must be made in generalizing these results to missions under terrain or vehicle speed different than what is used for this study, as well as those that include a longer immersion time.

Acute and chronic sleeping sickness are fatal neglected tropical diseases caused by Trypanosoma brucei rhodesiense and Trypanosoma brucei gambiense respectively (members of the sub-genus Trypanozoon). Accurate diagnostics are needed to guide treatment since the symptoms of disease are non-specific and the drugs that are used for treatment are too toxic to be administered to unconfirmed cases. Tests need to be simple enough to confirm clinical diagnosis of sleeping sickness in poorly-resourced, peripheral health centres and for use as epidemiological tools to detect T. b. rhodesiense in the zoonotic reservoirs of infection. This study focuses upon LAMP (loop-mediated isothermal amplification) as a novel diagnostic for sleeping sickness that may serve to bridge the gap between the need for sensitive, specific molecular diagnostics on the one hand and ‘field-friendly’ diagnostics on the other. Here, two previously published LAMP assays for Trypanozoons were compared to classic PCR based methods for the diagnosis of Trypanozoon infection status in 428 cattle blood samples. The results did not support the use of LAMP as an improved system for surveillance of T. b. rhodesiense in the zoonotic cattle reservoir. T. b. rhodesiense and T. b. gambiense subspecies specific LAMP assays were evaluated against traditional reference subspecies specific PCR tests, using DNA purified from 86 cryopreserved trypanosome isolates. Novel LAMP assays for these subspecies were also designed and evaluated. Both the published and novel assays for T. b. rhodesiense (targeting different regions of the SRA gene) were sensitive, specific and reliable when applied to purified DNAs, but were less consistent on field samples. The novel T. b. gambiense LAMP (targeting TgsGP) was sensitive and specific but this was not the case for the published LAMP assay (targeting the 5.8S rRNA gene). However reliability may be less than optimal for LAMP TgsGP. Finally, simple endpoint readout methods for LAMP were evaluated. The colour change reagent hydroxynaphthol blue was identified as the best currently available method taking cost, ease of use and reliability into consideration. In 2009 the number of reported sleeping sickness cases fell below 10,000 for the first time in 50 years. Improved LAMP diagnostics could facilitate the diagnosis of sleeping sickness and support the continued fight against this neglected, but deadly disease.

Media, trade unions and politicians have during the last years described social workers untenable work situation, and research shows that social workers are using strategies as sickness presence to deal with the imbalance between demands and resources. There is an interest in deepening knowledge of the phenomenon of sickness presence among social workers and to analyze the underlying causes that lead to the fact that social workers attend work while they are sick. The purpose of my study is to broaden knowledge for sickness presenteeism among social workers. I wanted to contribute to a better understanding of sickness presenteeism as phenomenon by analyzing social workers experience and wanted my study to focus on detailed descriptions of situations, events and feelings. Therefore I used a qualitative approach and based my study on individual interviews with 11 social workers. The social workers who chose to participate in the interviews are all women. I found several common strategies in the social workers descriptions, which were organized into three themes: loyalty, economy and resignation. The analysis was based on two different kinds of perspectives: one focusing on power and the other focusing on gender. The result shows that sickness presenteeism among social workers can be understood as a result of their attempt to live up to the prevailing male norms in society through paid work and to support the family, while they at the same time is expected to live up to the traditional image of ”a good girl" who prioritize the needs of others before her own health. The needs of others can appear in the form of, for example; clients, colleagues, family finances or the organization.

During the bloodstream stage of the Trypanosoma brucei lifecycle, the parasite exists in two different states: the proliferative slender form and the non-proliferative, transmissible, stumpy form. The transition from the slender to stumpy form is stimulated by a density-dependent mechanism and is important in infection dynamics, ordered antigenic variation and disease transmissibility. The slender to stumpy transition and the contribution of stumpy formation to within-host dynamics have been difficult to analyse, however, because cell-type specific markers have been restricted to imprecise morphological criteria. PAD1 is a recently identified stumpy-specific protein which acts as a molecular marker for stumpy formation and a functional marker for transmission. Here, the control of stumpy-specific gene expression via the 3’UTR has been analysed, identifying that there are repressive elements in the 3’UTR preventing inappropriate expression during the slender life stage. Further, both pleomorphic and monomorphic transgenic reporter cell lines utilising the PAD1 3’UTR have been created that report on stumpy formation in vitro and these have been used for the analysis of stumpyinducing chemical compounds. Finally, a sensitive and accurate qRT-PCR assay has been developed and optimised that faithfully reports both parasitaemia and stumpy formation throughout host infection. Using a chronic infection rodent model, stumpy levels have been monitored on the basis of conventional morphological and cell cycle assays, as well as by qRT-PCR for PAD1 expression. The results define the temporal order of events that result in the generation of stumpy forms early in a parasite infection and thereafter describe the dynamics of slender and stumpy forms in chronic infections extending over several weeks. This quantitative data has allowed the mathematical modelling of transmission competence in trypanosome infections, suggesting dominance of transmission stages throughout infection.

This thesis deconstructs the social, ecological, and colonial elements of the 1900-1910 Human African Trypanosomiasis (African Sleeping Sickness) epidemic which affected British Uganda and Belgian Congo. This paper investigates the epidemic’s medical history, and the subsequent social control policies which sought to govern the actions of the indigenous population. In addition, this paper argues that the failure to understand and respect the region’s ecological conditions and local knowledge led to disease outbreaks in epidemic proportions. Retroactive policies sought to inflict western medical practices on a non-western population, which resulted in conflict and unrest in the region. In the Belgian Congo, colonial authorities created a police state in which violence and stringent control measures were used to manage the local population. In Uganda, forced depopulation in infected regions destabilized local economies. This thesis compares and contrasts the methods used in these regions, and investigates the effects of Germ Theory on Sleeping Sickness policy and social perceptions during the colonial period in Africa.

Decompression sickness (DCS) results from a sudden decrease in ambient pressure leading to super-saturation of tissues with inert gas and subsequent bubble formation within both tissues and blood. Perfluorocarbons (PFC) are able to dissolve vast amounts of non-polar gases. The administration of intravenous (I.V.) PFC emulsions reduce both morbidity and mortality of DCS, but the mechanism of this protective effect has not yet been demonstrated. Juvenile Dorper cross sheep between 16 and 24 kg (n=31) were anaesthetized and instrumented for physiological monitoring, the administration of I.V. fluids and sampling of arterial and mixed venous blood. Animals were placed in a hyperbaric chamber and compressed to 6.0 atmospheres absolute for 30 minutes, then rapidly decompressed. Upon chamber exit animals were randomly assigned to receive 6cc/kg of either PFC or saline control over 5 minutes beginning immediately after chamber exit. They were also randomized to receive one of 4 breathing gases post-chamber: 100% O2, 80/20 N2/O2, 50/50 HeO2, or 80/20 HeO2. Blood samples were drawn at 5, 10, 15, 30, 60, and 90 minutes to examine whole-body oxygenation. Respiratory gases were monitored and recorded in real-time using mass spectroscopy to examine nitrogen washout. PFC administration increased arterial oxygen content (16.30±0.27 vs. 14.75±0.25 mL/dL, p<0.0001), oxygen delivery (14.83±0.28 vs. 13.44±0.25 mL/minute/kg, p=0.0004), and tissue oxygen consumption (3.37±0.14 vs. 2.76±0.13 mL/minute/kg, p=0.0018) over saline control, but did not increase mixed venous oxygen content (12.45±0.26 vs. 11.74±0.24 mL/dL, p=0.0558) or extraction ratio (0.23±0.012 vs. 0.21±0.011, p=0.1869). PFC administration lowered the plateau of the curve, increasing the amount of nitrogen washout vs. saline control (22.22±1.566 vs. 15.98±1.380 mmHg, p= 0.0074). Breathing 80/20 HeO2 increased the decay constant of the curve, increasing the rate of washout vs. breathing 100% O2 (0.03176±0.001044 vs. 0.03096±0.0009402, p=0.5777). PFC improves whole-body oxygenation after severe DCS and increases the amount of nitrogen washout. Although the effects of both PFC and 80/20 HeO2 breathing were statistically significant the magnitude of the nitrogen washout effect is quite small, and unlikely to be clinically significant. Thus it is likely that the improved oxygenation is responsible for the previously-observed therapeutic effects of PFC in treating DCS.

The global One Health movement has become firmly entrenched in both political and scientific discourse pertaining to emerging infectious diseases in the past decade. Since the discovery of the H5N1 strain of Highly Pathogenic Avian Influenza in Hong Kong in 1997, the promotion of more holistic programmes for the control of emerging infectious disease has garnered “unprecedented support” in terms of donor funding and political mobilisation (Scoones 2010). Advocates of One Health argue that intersectoral approaches promoting better communication between the veterinary, medical and environmental disciplines at all levels of governance make not only sound economic sense, they are fundamental to the “new approach” required to address the growing disease threats of the 21st century. However, despite international endorsement of the One Health rhetoric, there is growing pressure to now “turn the rhetoric into reality” (Okello et al 2011). Using a multiple, embedded case study methodology, this thesis seeks to examine questions surrounding the practical implementation of One Health interventions, particularly in developing countries which experience limited resources and competing health priorities. Through examining the livestock and public health policy processes at both local and national levels in Uganda and Nigeria, I attempt to identify whether policy spaces exist for the formal inclusion of One Health approaches in future policy decisions. Furthermore, by scrutinising the current internationally dominant One Health narratives in light of global health governance perspectives and the emerging One Health Global Network, I question whether One Health can be better “packaged” to include endemic diseases and a more focussed sustainable livelihoods approach; arguably inciting greater motivation for developing countries to truly participate. Data from my three empirical chapters are presented in the context of three overriding “One Health propositions” for consideration; by questioning “whose world, whose health”, I aim to delve further into the issues of not whether, but how this “new health paradigm” can be operationalised, and how to address the potential gaps which may ultimately prevent One Health from becoming a truly global phenomenon.

<p>The work presented in this dissertation is focused on applying engineering methods to develop and explore probabilistic survival models for the prediction of decompression sickness in US NAVY divers. Mathematical modeling, computational model development, and numerical optimization techniques were employed to formulate and evaluate the predictive quality of models fitted to empirical data. In Chapters 1 and 2 we present general background information relevant to the development of probabilistic models applied to predicting the incidence of decompression sickness. The remainder of the dissertation introduces techniques developed in an effort to improve the predictive quality of probabilistic decompression models and to reduce the difficulty of model parameter optimization.</p><p>The first project explored seventeen variations of the hazard function using a well-perfused parallel compartment model. Models were parametrically optimized using the maximum likelihood technique. Model performance was evaluated using both classical statistical methods and model selection techniques based on information theory. Optimized model parameters were overall similar to those of previously published Results indicated that a novel hazard function definition that included both ambient pressure scaling and individually fitted compartment exponent scaling terms. </p><p>We developed ten pharmacokinetic compartmental models that included explicit delay mechanics to determine if predictive quality could be improved through the inclusion of material transfer lags. A fitted discrete delay parameter augmented the inflow to the compartment systems from the environment. Based on the observation that symptoms are often reported after risk accumulation begins for many of our models, we hypothesized that the inclusion of delays might improve correlation between the model predictions and observed data. Model selection techniques identified two models as having the best overall performance, but comparison to the best performing model without delay and model selection using our best identified no delay pharmacokinetic model both indicated that the delay mechanism was not statistically justified and did not substantially improve model predictions.</p><p>Our final investigation explored parameter bounding techniques to identify parameter regions for which statistical model failure will not occur. When a model predicts a no probability of a diver experiencing decompression sickness for an exposure that is known to produce symptoms, statistical model failure occurs. Using a metric related to the instantaneous risk, we successfully identify regions where model failure will not occur and identify the boundaries of the region using a root bounding technique. Several models are used to demonstrate the techniques, which may be employed to reduce the difficulty of model optimization for future investigations.</p> / Dissertation

Esta tese tem como tema central o conceito de febre comportamental, que tem-se definido como o aumento da temperatura corporal pela efetivação da mudança nas temperaturas preferidas devido ao reconhecimento, por parte do corpo, de uma infecção ou patógeno. O trabalho está composto por três partes. Na Introdução Geral é discutida a febre comportamental em sete pontos fundamentais no entendimento desta resposta dentro da Ecofisiologia, começando pela definição, as pesquisas de laboratório e campo existente até o momento, até as limitações ecológicas dos indivíduos e as implicações do tema na conservação. No capítulo 1, com formato de texto científico, apresentamos a pesquisa na qual estudamos o comportamento e a preferência termal da espécie Proceratophrys boiei em condições experimentais com indivíduos injetados com lipopolisacáridos (LPS), para simular uma infecção, e indivíduos intactos (injetados com salina, grupo controle). Nessa pesquisa consideramos duas alternativas de respostas no comportamento, tal como discutido na introdução geral: a) febre comportamental, que é caracterizada por um aumento da temperatura corporal dos indivíduos pela mudança nas temperaturas preferidas dentro de uma paisagem termal; b) comportamento de doente, que no contexto do desenho experimental seria reconhecido pela diminuição da atividade dos indivíduos. Assim, registramos os seguintes tratamentos durante 24 horas com uma câmara termográfica: 1) indivíduos intactos no gradiente termal desligado, 2) indivíduos intactos no gradiente termal ligado, 3) indivíduos injetados com salina, no gradiente termal ligado 4) indivíduos injetados com LPS no gradiente termal ligado. Para cada um dos tratamentos foi registrada a distância de locomoção e as preferências termais, junto com outros detalhes do comportamento e as preferências termais. A partir de nossos resultados, concluímos que os indivíduos de P. boiei apresentam comportamento de doente como resposta dominante ao ser injetados com LPS, e que as preferências termais destes são consequência do comportamento de doente e não da termorregulação comportamental. Finalmente, a discussão geral explica como o capitulo 1 contribui na discussão de cada um dos sete pontos tratados na introdução geral tentando propor metodologias e estudos mais completos para manter o diálogo entre a fisiologia e a ecologia dos indivíduos no contexto de infecção e doenças / The central theme of this thesis is the concept of behavioral fever, which has been defined as the increase of body temperature by effecting the change in preferred temperatures due to the recognition by the body of an infection or pathogen. The thesis is composed of three parts. In the General Introduction, behavioral fever is presented around seven fundamental points to the understanding of this response within Ecophysiology, starting with the definition, the laboratory and field research until now, to the ecological limitations of individuals and the implications of this theme in conservation. In the first chapter, with scientific text format, we present the research in which we studied the behavior and thermal preference of Proceratophrys boiei species under experimental conditions in individuals injected with lipopolysaccharides (LPS), to simulate an infection, and in intact individuals (injected with Saline, a control group). In this research we considered two alternatives of behavioral responses, as discussed in the General Introduction: a) behavioral fever, which is characterized by an increase in the individuals body temperature by changing the preferred temperatures within a thermal landscape; B) patient behavior, which, in the context of experimental design, would be recognized by the decrease in the activity of individuals. Thus, we recorded the following treatments for 24 hours with a thermographic camera: 1) intact individuals in the thermal gradient switched off, 2) intact individuals in the connected thermal gradient, 3) individuals injected with saline, in the bound thermal gradient 4) individuals injected with LPS in the thermal gradient on. For each of the treatments it was recorded the locomotion distance and the thermal preferences, along with other details of the behavior and the thermal preferences. From our results, we conclude that the individuals of P. boiei present a patient\'s behavior as a dominant response when injected with LPS and their thermal preferences are a consequence of patient behavior and not behavioral thermoregulation. Finally, the general discussion explains how chapter 1 contributes to the discussion of each of the seven points highlighted in the general introduction attempting to propose a complete methodology and studies to maintain the dialogue between the physiology and the ecology of individuals in the context of infection and disease

The aim was to elucidate the social construction of chronic pain as a cause of work absence in the UK, focusing on negotiation of sickness certification and return to work, in the context of recent policies to tackle rising sick-listing rates, including a national educational programme about the health benefits of work, and introduction of the ‘fit note’. Following a literature review, two qualitative studies were conducted from a symbolic interactionist perspective. The first comprised semi-structured interviews with doctors and chronic pain patients, leading to a second study in which employers and employees with chronic pain were interviewed. Interviews were transcribed verbatim and analysed according to constructivist grounded theory principles. The first study revealed tensions in the doctor-patient relationship as the process of sickness certification was negotiated. The indeterminacy of chronic pain rendered the biomedical approach to diagnosis and assessment of capability for work problematic, while a shift to the psychosocial model could generate feelings of invalidation in patients. A wide range of moral and socio-cultural factors was invoked by doctors and patients to contest sick-listing decisions. The second study identified difficulties that can emerge when chronic pain patients return to work. Employees discussed how managers failed to understand their problems or make sustained adaptations; employers reported difficulty reconciling the needs of employees with organisational imperatives and argued that employees and doctors colluded in sanctioning low resilience. All stakeholder groups supported the fit note’s focus on capacity not incapacity, but were skeptical about whether it would surmount the tensions and difficulties that arise in sickness certification and return to work for chronic pain patients. Struggles for meaning and construction of identities are difficult for policy to address, but deeper understanding of the processes behind them and rich accounts of stakeholders’ views, may nudge the system towards more appropriate responses.