archives@tulane.edu / We extend the conventional models in mathematical epidemiology to account for more practical (yet complicated) situations in infectious disease transmissions, such as behavior change, risk level differentiation and infectiousness as a function of time since infection. We allow the transmission rate and recovery rate to vary as functions of time since infection. We present the derivation of the integral differential equation model and analyze the associated analytical and long-time solutions. We prove the well-posedness of an initial boundary value problem for the model. We also derive the threshold quantities for the epidemic to grow. We then extend the approach for the vector-borne infectious disease models. We compare several risk distribution functions due to geographic reasons. We construct the behavior change factor for the host population to account for different levels of infectiousness due to behavior distinction and behavior change. We establish the well-posedness of an initial boundary value problem of the new model. Sensitivity analysis shows that different risk distribution functions that are designed to adjust for spatial and geographic reasons have a large impact on the solution. / 1 / Li Guan

Literature concerning the time frames for detection of various seminal components commonly tested for in forensic laboratories in sexual assault cases is limited in quantity and in scope. Determining a more accurate time since intercourse (TSI) interval based on an extensive review of forensic case work would provide investigators with a tool for estimating the time elapsed between the occurrence of a sexual assault and the collection of a Sexual Assault Evidence Collection Kit (SAECK) which could be vital information in certain cases. This study demonstrates that the presence of intact spermatozoa is a significant finding on microscope slides prepared from vaginal, anorectal, and oral swabs and that the percentage of intact sperm cells decreases over time. This study also proved that sperm tails are lost during the preparation of microscope slides from SAECK swabs by directly comparing medical personnel-prepared smear slides and analyst-prepared extract slides from 95 Boston Police Department (BPD) Crime Laboratory Unit cases. Additionally, this study presents maximum TSI values for the persistence of sperm heads, intact spermatozoa, and prostate specific antigen (P30) through a retrospective examination of 355 cases processed by the BPD Crime Laboratory Unit over 5 years. The maximum persistence values for P30 in the vaginal, anorectal, and oral cavities were 19 hours, 17 hours, and 20 hours, respectively. In the vaginal cavity, maximum persistence values for intact spermatozoa were 43 hours for smear slides and 41.5 hours for extract slides. The maximum persistence of sperm heads was equivalent for vaginal smear and extract slides at 105 hours. In the anorectal cavity, maximum persistence values for intact spermatozoa were 43 hours for smear slides and 13 hours for extract slides. The maximum persistence of sperm heads was equivalent for anorectal smear and extract slides at 43 hours. In the oral cavity, maximum persistence values for intact spermatozoa were 3.75 hours for smear slides and 5 hours for extract slides. The maximum persistence of sperm heads were equivalent for oral smear and extract slides at 24 hours.

No description available.

<p>Mitt intresse för utomhuspedagogik har väckts under min lärarutbildning, speciellt på min verksamhetsförlagda utbildning där jag kunde observera hur utomhuspedagogiken används i skolan.</p><p>Syftet med studien är att undersöka vad utomhuspedagogik innebär för lärare, vilken inställning de har till elevernas inlärning inomhus respektive utomhus, anser de att utomhuspedagogik bidrar till elevers större förståelse för NO ämnen, i vilken utsträckning de använder utemiljön i sin NO undervisning samt vilka målsättningar lärare har för elevers lärande i utomhusmiljön.</p><p>Metod som jag har använt i min undersökning är den kvalitativa intervjumetoden där sex lärare har fått möjlighet att svara på ett antal frågor som handlar om utomhuspedagogiken och på det sättet fick de framhäva sin ställning och sina tankar.</p><p>Resultaten av min undersökning visar att majoriteten av de intervjuade lärarna har positiv inställning och uppfattning om utomhuspedagogiken samt att mer än hälften använder den i sin undervisning. Studien visar bland annat att olika metoder, avsikter och sammanhang varierar. Resultaten visar även att de lärarna som inte använder så mycket utomhusundervisning har angett tidsbristen och schemaplaneringen som orsak.</p> / <p>My interest for outdoor education has been awakened under mine education as teacher, especially during my practical training periods. There might I observed how the outdoor education was using in the school.</p><p>The aim of this study was to examine what outdoor education implies for teachers and which attitude they have to the students learning indoors respective outdoors education. I wondering if teachers deem that the outdoor education contributes to student’s major appreciation of science, in which extent they applies the outdoor environment in science tuition and what teacher want to attain with students learning in outdoor environment.</p><p>Method that I have used in my examination is the qualitative interview method there six teacher have got possibility to reply on a number of questions about outdoor education. In this manner they get explain theirs attitude and theirs minds about that.</p><p>The results of mine examination presents that the majority of the interviewer teachers have a positive attitude and appreciation about outdoor education and that more than half applies that in science tuition. The study further shows that the methods, intentions and context vary. The results presents even that teachers, who’s not applies outdoor education so much in science tuition had indicated lack of time and scheme planning as reason for that.</p>

Time-since-fire data are used to describe wildfire disturbances, the major disturbance type in the Boreal forest, over a landscape. These data can be used to calculate various parameters about wildfire disturbances, such as size, shape and severity. Collecting time-since-fire data is expensive and time consuming; the ability to derive it from existing forest inventory data would result in availability of fire data over larger areas. The objective of this thesis was to explore the use of forest inventory information for the prediction of time-since-fire data in the mixedwood boreal forests of Saskatchewan. Regression models were used to predict time-since-fire from forest inventory variables for each inventory polygon with a stand age. Non-water polygons with no stand age value were assigned values from neighbouring polygons, after splitting long polygons that potentially crossed many historic fire boundaries. This procedure filled gaps that prevented polygons from being grouped together in latter analysis. The predicted time-since-fire ages were used to generate wildfire parameters such as age-class distributions and fire cycle. Three methods were examined to group forest inventory polygons together to predict fire event polygons: simple partitions, hierarchical clustering, and spatially constrained clustering. The predicted fire event polygons were used to generate polygon size distribution wildfire metrics. I found that there was a relationship between time-since-fire and forest inventory variables at this study site, although the relationship was not strong. As expected, the strongest relationship was between the age of trees in a stand as indicated by the inventory and the time-since-fire. This relationship was moderately improved by including tree species composition, harvest modification value, and the ages of the surrounding polygons. Assigning no-age polygons neighbouring values and grouping the forest inventory polygons improved the predicted time-since-fire results when compared spatially to the observed time-since-fire data. However, a satisfactory method of comparing polygon shapes was not found, and the map outputs were highly dependent on the grouping method and parameters used. Overall it was found that forest inventory data did not have sufficient detail and accuracy to be used to derive high quality time-since-fire information.

Time-since-fire data are used to describe wildfire disturbances, the major disturbance type in the Boreal forest, over a landscape. These data can be used to calculate various parameters about wildfire disturbances, such as size, shape and severity. Collecting time-since-fire data is expensive and time consuming; the ability to derive it from existing forest inventory data would result in availability of fire data over larger areas. The objective of this thesis was to explore the use of forest inventory information for the prediction of time-since-fire data in the mixedwood boreal forests of Saskatchewan. Regression models were used to predict time-since-fire from forest inventory variables for each inventory polygon with a stand age. Non-water polygons with no stand age value were assigned values from neighbouring polygons, after splitting long polygons that potentially crossed many historic fire boundaries. This procedure filled gaps that prevented polygons from being grouped together in latter analysis. The predicted time-since-fire ages were used to generate wildfire parameters such as age-class distributions and fire cycle. Three methods were examined to group forest inventory polygons together to predict fire event polygons: simple partitions, hierarchical clustering, and spatially constrained clustering. The predicted fire event polygons were used to generate polygon size distribution wildfire metrics. I found that there was a relationship between time-since-fire and forest inventory variables at this study site, although the relationship was not strong. As expected, the strongest relationship was between the age of trees in a stand as indicated by the inventory and the time-since-fire. This relationship was moderately improved by including tree species composition, harvest modification value, and the ages of the surrounding polygons. Assigning no-age polygons neighbouring values and grouping the forest inventory polygons improved the predicted time-since-fire results when compared spatially to the observed time-since-fire data. However, a satisfactory method of comparing polygon shapes was not found, and the map outputs were highly dependent on the grouping method and parameters used. Overall it was found that forest inventory data did not have sufficient detail and accuracy to be used to derive high quality time-since-fire information.

Mitt intresse för utomhuspedagogik har väckts under min lärarutbildning, speciellt på min verksamhetsförlagda utbildning där jag kunde observera hur utomhuspedagogiken används i skolan. Syftet med studien är att undersöka vad utomhuspedagogik innebär för lärare, vilken inställning de har till elevernas inlärning inomhus respektive utomhus, anser de att utomhuspedagogik bidrar till elevers större förståelse för NO ämnen, i vilken utsträckning de använder utemiljön i sin NO undervisning samt vilka målsättningar lärare har för elevers lärande i utomhusmiljön. Metod som jag har använt i min undersökning är den kvalitativa intervjumetoden där sex lärare har fått möjlighet att svara på ett antal frågor som handlar om utomhuspedagogiken och på det sättet fick de framhäva sin ställning och sina tankar. Resultaten av min undersökning visar att majoriteten av de intervjuade lärarna har positiv inställning och uppfattning om utomhuspedagogiken samt att mer än hälften använder den i sin undervisning. Studien visar bland annat att olika metoder, avsikter och sammanhang varierar. Resultaten visar även att de lärarna som inte använder så mycket utomhusundervisning har angett tidsbristen och schemaplaneringen som orsak. / My interest for outdoor education has been awakened under mine education as teacher, especially during my practical training periods. There might I observed how the outdoor education was using in the school. The aim of this study was to examine what outdoor education implies for teachers and which attitude they have to the students learning indoors respective outdoors education. I wondering if teachers deem that the outdoor education contributes to student’s major appreciation of science, in which extent they applies the outdoor environment in science tuition and what teacher want to attain with students learning in outdoor environment. Method that I have used in my examination is the qualitative interview method there six teacher have got possibility to reply on a number of questions about outdoor education. In this manner they get explain theirs attitude and theirs minds about that. The results of mine examination presents that the majority of the interviewer teachers have a positive attitude and appreciation about outdoor education and that more than half applies that in science tuition. The study further shows that the methods, intentions and context vary. The results presents even that teachers, who’s not applies outdoor education so much in science tuition had indicated lack of time and scheme planning as reason for that.

It has been argued that organic farming sustains a higher biodiversity than conventional farming. This might promote the ecosystem services that exist in agricultural landscapes such as pollination and pest control. Here, I examined the effect of farming system (organic vs. conventional) with respect to the time since farming system transition, landscape heterogeneity and plant richness on pollinating and predatory insects. In total, data from 30 farms were used, of which 20 were organic and 10 were conventional. The data were analyzed using general linear models and model averaging. The results show that insect groups responded differently to various factors. Pollinators were more sensitive to landscape complexity, showing an increase of abundance and species richness with an increased heterogeneity. Predators on the other hand reacted to farming system, where there was an increase in abundance and species richness on organic farms.

This thesis investigates the effects of immigration status, country of origin, and duration in Canada on three main health outcomes, namely health care utilization, occurrences of hypertension and heart disease, and body mass index. The first two chapters are cross-sectional studies that utilize data derived from linked national health survey and Ontario databases, whereas the third chapter is a longitudinal study which draws data from the longitudinal National Population Health Survey (NPHS). The first chapter examines the role of immigration status and country of origin in explaining the use of three types of health services: primary care physicians, specialists, and hospitals. The findings suggest that immigrants, especially those who are male and have low educational attainment, use more primary care physicians than comparable non-immigrants. However, immigrants are found to use fewer expensive health services, i.e. specialist and hospital care, compared to Canadian-born residents. Likewise, immigrants from non-traditional source countries make even fewer visits to specialists than do those who came from traditional source countries. The second chapter investigates the associations of immigration status, occurrence of hypertension, and occurrence of heart disease. Findings from this chapter show that immigrants have comparable odds of hypertension and heart disease to those of Canadian-born residents after adjusting for other factors. The third chapter examines the effects of time since arrival in Canada on the change in BMI over the 14-year period. This chapter shows that, holding other factors constant, an additional year in Canada leads to a 0.14% increase in an individual’s BMI. This association is found to be more pronounced for women than men and for married than non-married individuals. The effect of time since arrival in Canada on the change in BMI is reduced to 0.07% after controlling for sample selection bias, suggesting that by ignoring the sample selection issue, the effects of time since arrival in Canada on the change in BMI may be overestimated.

This thesis investigates the effects of immigration status, country of origin, and duration in Canada on three main health outcomes, namely health care utilization, occurrences of hypertension and heart disease, and body mass index. The first two chapters are cross-sectional studies that utilize data derived from linked national health survey and Ontario databases, whereas the third chapter is a longitudinal study which draws data from the longitudinal National Population Health Survey (NPHS). The first chapter examines the role of immigration status and country of origin in explaining the use of three types of health services: primary care physicians, specialists, and hospitals. The findings suggest that immigrants, especially those who are male and have low educational attainment, use more primary care physicians than comparable non-immigrants. However, immigrants are found to use fewer expensive health services, i.e. specialist and hospital care, compared to Canadian-born residents. Likewise, immigrants from non-traditional source countries make even fewer visits to specialists than do those who came from traditional source countries. The second chapter investigates the associations of immigration status, occurrence of hypertension, and occurrence of heart disease. Findings from this chapter show that immigrants have comparable odds of hypertension and heart disease to those of Canadian-born residents after adjusting for other factors. The third chapter examines the effects of time since arrival in Canada on the change in BMI over the 14-year period. This chapter shows that, holding other factors constant, an additional year in Canada leads to a 0.14% increase in an individual’s BMI. This association is found to be more pronounced for women than men and for married than non-married individuals. The effect of time since arrival in Canada on the change in BMI is reduced to 0.07% after controlling for sample selection bias, suggesting that by ignoring the sample selection issue, the effects of time since arrival in Canada on the change in BMI may be overestimated.