• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 14
  • 1
  • 1
  • 1
  • Tagged with
  • 19
  • 9
  • 9
  • 6
  • 6
  • 5
  • 5
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Wildlife surveillance systems : chronic wasting disease

Tataryn, Joanne Rosemary 17 September 2009
Increased demand for animal disease surveillance information has led to the development and refinement of methodologies for qualitative and quantitative surveillance system evaluations to maximize efficiency and efficaciousness. The impetus for this surveillance evaluation project was chronic wasting disease (CWD) and the objectives were to apply both qualitative and quantitative methodologies to examine the components of CWD surveillance in Saskatchewan.<p> A retrospective review of deer pathology and hunter-harvest submissions in Saskatchewan was conducted through the Canadian Cooperative Wildlife Health Centre. Qualitative evaluation methods outlined by Klauke et al (1988) were used and included key stakeholder interviews. A quantitative evaluation, with specific focus on disease detection, was conducted to examine system sensitivity, confidence of disease freedom and to compare system components using methods described by Martin et al (2007). The analysis was conducted using a scenario tree and Monte Carlo simulation.<p> Sampling rates of dead and clinically ill deer were low with a high degree of variability by season, year, location and nature of submissions. Ultimately, variability of submission patterns likely affected when and where diseases were detected. Poor data quality reduced the amount of available data for analysis but quality dramatically improved over time.<p> The surveillance evaluation demonstrated that the current surveillance system places more emphasis on monitoring trends in CWD-positive areas, at the expense of early detection. This is explained mostly by the coupling of disease control efforts and surveillance, in that harvests are heavily focused in CWD-positive areas. The system is not sufficient to detect disease in new areas where the disease prevalence is low, primarily due to low submission rates.<p> The quantitative evaluation found that overall sensitivity of the surveillance system and confidence of disease freedom was highly dependent on detection prevalence and the ongoing risk of disease introduction. Surveillance in the eastern part of Saskatchewan was not adequate from 1997-2006 to detect CWD at 0.5-1% prevalence. However, if risk of CWD introduction over this time period was assumed to be low, it can be concluded that the prevalence in this region was not 5% or higher.<p> A detection goal of 0.5-1% prevalence is an ambitious surveillance goal, especially in areas where the risk of disease introduction is high. The use of more targeted surveillance strategies should be further explored to help better meet surveillance these surveillance objectives.
2

Wildlife surveillance systems : chronic wasting disease

Tataryn, Joanne Rosemary 17 September 2009 (has links)
Increased demand for animal disease surveillance information has led to the development and refinement of methodologies for qualitative and quantitative surveillance system evaluations to maximize efficiency and efficaciousness. The impetus for this surveillance evaluation project was chronic wasting disease (CWD) and the objectives were to apply both qualitative and quantitative methodologies to examine the components of CWD surveillance in Saskatchewan.<p> A retrospective review of deer pathology and hunter-harvest submissions in Saskatchewan was conducted through the Canadian Cooperative Wildlife Health Centre. Qualitative evaluation methods outlined by Klauke et al (1988) were used and included key stakeholder interviews. A quantitative evaluation, with specific focus on disease detection, was conducted to examine system sensitivity, confidence of disease freedom and to compare system components using methods described by Martin et al (2007). The analysis was conducted using a scenario tree and Monte Carlo simulation.<p> Sampling rates of dead and clinically ill deer were low with a high degree of variability by season, year, location and nature of submissions. Ultimately, variability of submission patterns likely affected when and where diseases were detected. Poor data quality reduced the amount of available data for analysis but quality dramatically improved over time.<p> The surveillance evaluation demonstrated that the current surveillance system places more emphasis on monitoring trends in CWD-positive areas, at the expense of early detection. This is explained mostly by the coupling of disease control efforts and surveillance, in that harvests are heavily focused in CWD-positive areas. The system is not sufficient to detect disease in new areas where the disease prevalence is low, primarily due to low submission rates.<p> The quantitative evaluation found that overall sensitivity of the surveillance system and confidence of disease freedom was highly dependent on detection prevalence and the ongoing risk of disease introduction. Surveillance in the eastern part of Saskatchewan was not adequate from 1997-2006 to detect CWD at 0.5-1% prevalence. However, if risk of CWD introduction over this time period was assumed to be low, it can be concluded that the prevalence in this region was not 5% or higher.<p> A detection goal of 0.5-1% prevalence is an ambitious surveillance goal, especially in areas where the risk of disease introduction is high. The use of more targeted surveillance strategies should be further explored to help better meet surveillance these surveillance objectives.
3

The economic impacts of chronic wasting disease on hunting in Alberta: a multi-year study

Pascoe, Katherine Jane Unknown Date
No description available.
4

Factors affecting movement patterns of mule deer (<i>Odocoileus hemionus</i>) in southern Saskatchewan : implications for chronic wasting disease spread

Silbernagel, Erin Rae 08 April 2010
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.
5

Factors affecting movement patterns of mule deer (<i>Odocoileus hemionus</i>) in southern Saskatchewan : implications for chronic wasting disease spread

Silbernagel, Erin Rae 08 April 2010 (has links)
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.
6

14C測定による粗大枯死材の枯死年および分解速度の推定

OSONO, Takashi, ITO, Koichi, MINAMI, Masayo, HISHINUMA, Takuya, 大園, 亨司, 伊藤, 公一, 南, 雅代, 菱沼, 卓也 03 1900 (has links)
第23回名古屋大学年代測定総合研究センターシンポジウム平成22(2010)年度報告
7

Factors affecting movement patterns of mule deer (Odocoileus hemionus) in southern Saskatchewan : implications for chronic wasting disease spread

04 1900 (has links)
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.
8

New Social Media, Risk Communication, and Wildlife Health: Implications for Indigenous Communities of Saskatchewan and Alberta, Canada

Odunuga, Babawale 15 July 2014 (has links)
The study involved Indigenous communities of Saskatchewan and Alberta which are adversely impacted by industrial activities in their traditional territory. The overall goal of this study is: the assessment of social media in risk studies among Indigenous communities of western Canada. The methods used were: interviews, focus group discussion (FGD), and net-mapping. Results showed that the majority of youths communicated around risk using new social media (NSM) in event of risk outbreak, while Indigenous Elders, communicated face-to-face and via cell-phone. Results also showed that youths use Traditional Knowledge learnt from the Elders to understand Chronic wasting disease (CWD) risk, interpret, communicate and mobilize around mitigation. The study concluded that the use of NSM is becoming increasingly important for scoping information around wildlife decline and emergency in these Indigenous communities.
9

Saproxylic beetles in Populus tremula fauna depots - how do you construct the best depot?

Selberg, Simon January 2019 (has links)
The biodiversity of saproxylic organisms and in the case of this study, saproxylic beetles, is dependent on the amount and quality of course woody debris (CWD) in the environment. Over the past decades the quantity of CWD in Swedish forests has increased, yet the quality has decreased, forests are managed and exploited, and old-growth forests are rarer. To counteract this, fauna depots, artificial piles of dead wood, can be placed to increase the amount and quality of habitat for saproxylic organisms. This study measured fauna depots of aspen CWD placed in Uppsala municipality to find which combination of qualities resulted in the highest species richness and abundance (diversity). A total of 242 beetles across 26 species were sampled using a bark sifter and Tullgren extraction funnels. The CWD qualities; number of logs, log diameter, sun exposure and decomposition level were measured. Log diameter was confirmed to be positively correlated with species richness supporting previous research. Decomposition was also positively correlated with species richness, but this not supported by previous research. Some qualities, like sun exposure, were unexpectedly not correlated and number of logs was negatively correlated. Only one red-listed species was found across all samples. Overall results were somewhat inconclusive but provide hints towards better practice in saproxylic beetle conservation, such as placing larger logs in the depots.
10

Intensification par détente instantanée contrôlée (DIC) de la fonctionnalisation physico-chimiques [sic] des graines végétales (caroube et tournesol) / Intensification by instant controlled pressure drop (DIC) of physico-chimical functionalization of vegetable seeds (carob and sunflower)

Zeaiter, Amal 28 September 2018 (has links)
La présente thèse traite, au travers d’une analyse fondamentale et expérimentale, l’effet de texturation par détente instantanée contrôlée (DIC) sur les phénomènes de transfert au cours des processus de séchage, d’extraction mécanique et de comportement rhéologique. Les produits concernés ont été les graines de caroube (gomme et germe) et deux variétés de graines de tournesol (linoléique et oléique). La texturation DIC permet d’agir sur la cinétique de séchage par flux d’air ce qui conduit à une intensification des processus de séchage par flux d’air tout en assurant une bonne préservation de la qualité nutritionnelle du produit fini. L’étude expérimentale a été couplée à une analyse phénoménologique de la cinétique à travers une modélisation de type CWD (coupled Washing/Diffusion). Cette dernière étude conduit à une évaluation de l’impact de la texturation sur la diffusivité effective Deff et l’accessibilité initiale δWs. D’autre part, l’étude expérimentale en vue de l’optimisation de l’opération a été réalisée à travers la méthode des plans d’expériences. La modification des paramètres opératoires fonctionnels de la DIC, à savoir la pression absolue de vapeur d’eau saturée sèche (P), et le temps de traitement thermique (t), ainsi que le nombre des cycles (c) sur l’ensemble des performances de l’opération a été établie sur le comportement rhéologique de la gomme de caroube. Une deuxième partie de la thèse a été consacrée à l’étude fondamentale et expérimentale des procédés d’extraction d’huile de tournesol des deux variétés de graines linoléiques et oléiques. Le traitement thermomécanique par détente instantanée contrôlée (DIC) permet, à travers une modification contrôlée de la structure de la matière première, d’agir sur l’extraction mécanique par presse à froid des huiles de tournesol, ainsi que sur l’extraction par solvant de l’huile à partir du tourteau résiduel. Un complément à cette opération a consisté en l’extraction par solvant (n-hexane) opérée sur l’ensemble des graines de tournesol. La texturation DIC a conduit à une grande augmentation du rendement en huile pour les variétés linoléique et oléique. La préservation de la qualité de l’huile et du tourteau prouve l’adéquation de la DIC avec l’absence pratique de la dégradation chimique. Notre étude a également concerné la définition d’un nouveau procédé de désodorisation. Il s’agit de l’utilisation de l’Autovaporisation Multi-Flash MFA sur le raffinage de l’huile de tournesol. Cette technologie innovante de désodorisation se distingue par son faible niveau de température assurant ainsi une sévérité nettement inférieure à celle des méthodes conventionnelles à haute température. / This thesis deals with a fundamental and experimental analysis of the effect of instant controlled pressure drop (DIC) on the transfer phenomena and rheological behavior, which occurs during the drying process and mechanical and solvent extraction. The products concerned were carob seeds (gum and germ) and two varieties of sunflower seeds (linoleic and oleic). DIC texturing makes it possible to greatly modify the drying kinetics, leading to an effective intensification of the drying processes while maintaining a good preservation of the nutritional quality of the finished product. The experimental study was coupled with a phenomenological kinetic model using the CWD (coupled Washing/Diffusion). This study leads to evaluate the impact of texturing on the effective diffusivity Deff and the initial accessibility δWs. On the other hand, the experimental study for the optimization of the operation was carried out through an adequate experimental design method. The impact of the DIC processing parameters, namely the absolute pressure of saturated dry water vapor (P), and the heat treatment time (t), as well as the number of cycles (c) was established on the rheological behavior of the carob bean gum. A second part of our work was devoted to the theoretical and experimental study of sunflower oil extraction processes of the two types of linoleic and oleic seeds. By acting as a controlled modification of the raw material, (DIC) texturing allowed increasing the yield of sunflower oil by both cold pressing and solvent extraction from the residual cake. DIC texturing has led to a large increase in oil yield for both linoleic and oleic varieties. The preservation of the quality of oil demonstrates that DIC was perfectly adequate with a perfect absence of chemical degradation. Our study also involved the definition of a new deodorization process. This is the use of the Multi-Flash Autovaporization MFA on the refining of sunflower oil. This innovative deodorization technology is characterized by its low temperature level, thus ensuring a much lower severity than conventional high temperature methods.

Page generated in 0.021 seconds