Master of Science / Department of Mechanical and Nuclear Engineering / Mohammad H. Hosni / Byron W. Jones / Due to the high occupant density and large number of travelers on commercial aircraft, it is crucial to limit the transport of contaminants and pathogens amongst passengers. In order to minimize the exposure of passengers to various contaminants of different sizes and characteristic, all mechanisms influencing airflow movement within an aircraft cabin need to be understood. The use of personal gaspers on commercial aircraft and their relation to airborne contaminants and pathogens transport is one such mechanism that was investigated. Tracer gas testing using carbon dioxide (CO[subscript]2) was conducted in a wide-body, 11-row Boeing 767 aircraft cabin mockup using actual aircraft components for air distribution. Three separate experiments were conducted investigating the effect of gaspers on the transport of contaminants. The first series of experiments focused on the effect of gaspers on longitudinal transport patterns within an aircraft cabin environment by measuring the concentration of tracer gas along the length of the aircraft cabin. The second experiment investigated what fraction of air a passenger inhales originates from a gasper in relation to the overall cabin ventilation. The final set of experiments determined if gaspers could limit close range person-to-person transmission of exhaled contaminants. Three separate sets of conclusions were drawn, one for each series of experiments. The first conclusion is that gaspers disrupt the longitudinal transport of contaminants within the aircraft cabin. The second conclusion is that less than 5% of the air inhaled by a passenger is originating from a gasper even with a gasper directed at the passenger's face. This low percentage is a result of the turbulent airflow within the aircraft cabin causing the gasper jet to quickly mix with the overall cabin ventilation air. The last conclusion is that gaspers can reduce person-to-person transmission of exhaled contaminants as much as nearly 90% in some cases. In other cases the gaspers are found to have negligible or negative impact on the transmission of contaminants. These conclusions are dependent upon where the tracer gas plume emanated from, the sampling location, and the configuration of gaspers around the tracer gas release point.

<p>ABSTRACTAim: Since 2003 Kilimanjaro Aids Control Association (KACA) has collaborated with the Mawenzi Hospital in Moshi, in order to prevent the transmission of HIV/AIDS. The aim of this study was to investigate Mawenzi Hospital’s staff’s views about KACA and its work.   Method: Eight semi structured interviews were performed with nurses and physicians. The interviews were recorded, transcribed and analyzed by a qualitative manifest content analysis according to Graneheim and Lundman (2004).  Results: All the informants mentioned that KACA is an important stakeholder needed in the collaboration with the government to prevent HIV transmission. They also mentioned that the main problems KACA struggles with is lack of recourses, insufficient HIV tests and lack of information to their clients. KACA was described as an accessible non governmental organization (NGO) working as a bridge from society, channeling HIV positive clients to Mawenzi Hospital. Conclusion: This study confirms that KACA is considered doing a good job and is appreciated by the nurses and physicians at the Mawenzi Hospital. For KACA this may be important information to maintain their prevention work. The problems presented by the informants should be taken under consideration when planning the future work.</p>

ABSTRACTAim: Since 2003 Kilimanjaro Aids Control Association (KACA) has collaborated with the Mawenzi Hospital in Moshi, in order to prevent the transmission of HIV/AIDS. The aim of this study was to investigate Mawenzi Hospital’s staff’s views about KACA and its work.   Method: Eight semi structured interviews were performed with nurses and physicians. The interviews were recorded, transcribed and analyzed by a qualitative manifest content analysis according to Graneheim and Lundman (2004).  Results: All the informants mentioned that KACA is an important stakeholder needed in the collaboration with the government to prevent HIV transmission. They also mentioned that the main problems KACA struggles with is lack of recourses, insufficient HIV tests and lack of information to their clients. KACA was described as an accessible non governmental organization (NGO) working as a bridge from society, channeling HIV positive clients to Mawenzi Hospital. Conclusion: This study confirms that KACA is considered doing a good job and is appreciated by the nurses and physicians at the Mawenzi Hospital. For KACA this may be important information to maintain their prevention work. The problems presented by the informants should be taken under consideration when planning the future work.

The world population is growing and becoming more connected whereby disease transmission is becoming an increasingly important issue. To learn more about disease spread, honey bees (Apis mellifera) could provide an animal-model system for network transmission. The honey bees have both an individual and a social defense against pathogens, their diseases are well studied and they enable studies on hundreds of individuals. The genetic relatedness is believed to be one of many important factors for disease transmission. A hypothesis is that the more closely related the honey bees are the more interactions will occur. In this study, the genetic relatedness in honey bees was analyzed by the use of microsatellite-DNA primers, in a multiplex PCR. Of the 18 microsatellite-DNA primers that were evaluated, the loci HB-C16-05, A007, AC006, HB-C16-02, AP043 and UN351 showed the highest variation. However, when applied on a larger material, the PCR-products did not yield any chromatograms that were possible to score. Many factors possibly affecting the result are discussed and further efforts will be made to improve the method and thereby determine genetic relatedness.

Chronic wasting disease (CWD) has been a known threat to Saskatchewans wild cervid populations for more than a decade. As host movements can affect the spread of a disease across the landscape, disease models and management strategies should incorporate information regarding movement patterns of the host population in question. I used radio telemetry to study mule deer (<i>Odocoileus hemionus</i>) captured between 2006 and 2008 in a CWD-endemic region of southern Saskatchewan. Using location data from 152 individuals, I investigated home range size and patterns of direct and indirect contact (measured using proximity and shared space use) in relation to sex, habitat, and landscape structure. <p>Home ranges (95% fixed kernel) of GPS-collared deer in this study averaged 21.4 km² (n = 94). Male home ranges (mean = 29.5 km², n = 56) were larger than those of females (mean = 16.1 km², n = 38), which could have implications for CWD prevalence differences between sexes. Of the landscape variables tested, topographic ruggedness was inversely related to home range size and Shannons diversity (a measure of both habitat richness and evenness) was positively related to home range size. <p>Potential direct contact events were identified when two deer were located within 25 m of each other at the same point in time. These events occurred more often between February and April, agreeing with the tendency of mule deer to aggregate into large groups during the late winter months, and suggesting that this may be an important time period for disease transmission. Contact also occurred more than expected in cropland, whereas areas of shared use occurred more than expected in grassland, shrub/wood habitat, and rugged terrain. Smaller home ranges and greater degree of shared space use within areas of rough topography may lead to greater risk of environmental contamination with the infectious CWD agent in these areas. In contrast, the relationship between cropland and probability of direct contact may imply greater risk of direct CWD transmission between deer occupying this habitat. <p>These results identify connections between particular landscape factors and risk of CWD transmission and will be used, in combination with results of related studies, to develop a model of CWD spread in Saskatchewan. This will in turn aid management agencies in developing methods to more effectively manage the disease and control its movement outside of affected regions.

Chronic wasting disease (CWD) has been a known threat to Saskatchewans wild cervid populations for more than a decade. As host movements can affect the spread of a disease across the landscape, disease models and management strategies should incorporate information regarding movement patterns of the host population in question. I used radio telemetry to study mule deer (<i>Odocoileus hemionus</i>) captured between 2006 and 2008 in a CWD-endemic region of southern Saskatchewan. Using location data from 152 individuals, I investigated home range size and patterns of direct and indirect contact (measured using proximity and shared space use) in relation to sex, habitat, and landscape structure. <p>Home ranges (95% fixed kernel) of GPS-collared deer in this study averaged 21.4 km² (n = 94). Male home ranges (mean = 29.5 km², n = 56) were larger than those of females (mean = 16.1 km², n = 38), which could have implications for CWD prevalence differences between sexes. Of the landscape variables tested, topographic ruggedness was inversely related to home range size and Shannons diversity (a measure of both habitat richness and evenness) was positively related to home range size. <p>Potential direct contact events were identified when two deer were located within 25 m of each other at the same point in time. These events occurred more often between February and April, agreeing with the tendency of mule deer to aggregate into large groups during the late winter months, and suggesting that this may be an important time period for disease transmission. Contact also occurred more than expected in cropland, whereas areas of shared use occurred more than expected in grassland, shrub/wood habitat, and rugged terrain. Smaller home ranges and greater degree of shared space use within areas of rough topography may lead to greater risk of environmental contamination with the infectious CWD agent in these areas. In contrast, the relationship between cropland and probability of direct contact may imply greater risk of direct CWD transmission between deer occupying this habitat. <p>These results identify connections between particular landscape factors and risk of CWD transmission and will be used, in combination with results of related studies, to develop a model of CWD spread in Saskatchewan. This will in turn aid management agencies in developing methods to more effectively manage the disease and control its movement outside of affected regions.

Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 110-117).

Chronic wasting disease (CWD) has been a known threat to Saskatchewan’s wild cervid populations for more than a decade. As host movements can affect the spread of a disease across the landscape, disease models and management strategies should incorporate information regarding movement patterns of the host population in question. I used radio telemetry to study mule deer (Odocoileus hemionus) captured between 2006 and 2008 in a CWD-endemic region of southern Saskatchewan. Using location data from 152 individuals, I investigated home range size and patterns of direct and indirect contact (measured using proximity and shared space use) in relation to sex, habitat, and landscape structure. Home ranges (95% fixed kernel) of GPS-collared deer in this study averaged 21.4 km² (n = 94). Male home ranges (mean = 29.5 km², n = 56) were larger than those of females (mean = 16.1 km², n = 38), which could have implications for CWD prevalence differences between sexes. Of the landscape variables tested, topographic ruggedness was inversely related to home range size and Shannon’s diversity (a measure of both habitat richness and evenness) was positively related to home range size. Potential direct contact events were identified when two deer were located within 25 m of each other at the same point in time. These events occurred more often between February and April, agreeing with the tendency of mule deer to aggregate into large groups during the late winter months, and suggesting that this may be an important time period for disease transmission. Contact also occurred more than expected in cropland, whereas areas of shared use occurred more than expected in grassland, shrub/wood habitat, and rugged terrain. Smaller home ranges and greater degree of shared space use within areas of rough topography may lead to greater risk of environmental contamination with the infectious CWD agent in these areas. In contrast, the relationship between cropland and probability of direct contact may imply greater risk of direct CWD transmission between deer occupying this habitat. These results identify connections between particular landscape factors and risk of CWD transmission and will be used, in combination with results of related studies, to develop a model of CWD spread in Saskatchewan. This will in turn aid management agencies in developing methods to more effectively manage the disease and control its movement outside of affected regions.

The purpose of this study was to determine the efficacy of infant feeding choices and support provided in the current PMTCT programme in KwaZulu-Natal. A case study format was utilised. Follow-up was done over six months with ten HIV positive women enrolled in the PMTCT programme at St. Apollinaris Hospital. Transcripts of interviews were made, pattern-matching was done, and the process of replication was used to develop a cross-case report as the final analysis of the study. All of the women decided to and intended to exclusively breastfeed for between four and six months at the time of the first interview. There was a poor rate of return for follow-up interviews, therefore the actual feeding practice of half of the women after six weeks could not be determined. The case studies were developed with the information available, and thus conclusions were reached during cross-case analysis. Decision-making ability and the capacity to overcome the barriers to the maintenance of their original feeding choice were related to the women's educational levels, employment status, financial and social circumstances and support systems, knowledge and experience of HIV/AIDS, quality of PMTCT education and support, cultural beliefs, and parenting and family values. The age of respondents and differences in marital status had no obvious correlation to maintenance of feeding choice. Parity and level of education had only a limited effect on maintenance of feeding choice. Cues to mixed feeding included a fatalistic view and a loss of hope for preventing transmission of HIV to their infants. Some of the women did not seem to believe that maintaining a specific infant feeding regime was enough to prevent transmission of HIV to their infants. Fear of stigmatisation due to disclosure of their positive HIV status led to non-disclosure of many women, and this in turn led to a lack of support for their feeding choice. Cues to exclusive feeding included an internal pressure to succeed and so decrease the chances of HIV transmission to her infant. Those women who disclosed their HIV status to a significant other and established a good support system were more likely to maintain their original decision. Although none of the women enjoyed good social circumstances, those who were more financially secure, employed, and who had a stable home environment were more likely to maintain their exclusive feeding regime. / Thesis (M.N.)-University of KwaZulu-Natal, Durban, 2004.

Uninfected nymphs of Ixodes scapularis and Amblyomma americanum were fed on hamsters that had been injected intraperitoneally with a 0.5 ml sample of Borrelia burgdorferi (2.5 X 10' spirochetes per ml) 30 days earlier. All nymphs fed to repletion and were then housed during the molting process. In order to assess their ability to transmit the spirochetes, the resulting l. scapularis and A. americanum adults were allowed to feed on uninfected rabbits.Dissection of the adult l. scapularis ticks revealed 9/12 (75%) to harbor motile spirochetes, identified as B. burgdorferi by darkfield microscopy, isolation in BSK II medium, and indirect immunofluorescent antibody staining with the monoclonal antibody H5332. Transmission was successful to one of two New Zealand White rabbits by these infected ticks.Dissection of the adult A. americanum ticks revealed 0/150 (0%) to harbor spirochetes. Transmission to each of three rabbits was unsuccessful. However, 5/90 (5.6%) cultures of midgut material from these same ticks, harbored non-motile spirochete-like bodies. The identity of these "spirochetes" is unknown. / Department of Biology