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  • 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

Implementation of in-field life detection and characterisation techniques in icy environments

Barnett, Megan January 2010 (has links)
An emerging trend towards non-laboratory based biological and microbiological marker analysis is occurring in multiple sectors of science and industry. In the medical sector, these trends have demonstrated that conducting sample analyses away from centralised laboratories not only makes analyses quicker and more convenient (e.g. a home pregnancy test), but can offer services that are otherwise impractical (e.g. mobile laboratories to diagnose disease in the developing world). In the environmental sector, similar benefits, plus the ability to develop and test hypotheses, protocols and sampling strategies within a field campaign, are possible with in-field analyses. Icy environments in particular would benefit from in situ or in-field life detection as they are typically remote, and hence impart high logistical costs for repeated field campaigns and associated sample return with the implication that the efficiency of scientific return is poor. Unfortunately, most equipment and protocols developed for microbiological analyses in other sectors of science and industry are unsuitable for direct application to in-field use in icy environments because of poor compatibility with icy environment sample matrices and frequently inappropriate microbiological targets. Hence within this work, two hypotheses were tested: that (i) microbiological detection infield in icy environments is possible and through this (ii) unique and more efficient scientific studies can be conducted. Cont/d.
2

Caffeine Supplementation and Moderate Intensity Exercise Modulates the Cytotoxic Lymphocyte Subset (CD+8) in NaIve and Tolerant Individuals

Fedor, Elizabeth Ann 01 December 2010 (has links)
The purpose of this investigation was to determine the effects of caffeine supplementation on caffeine tolerant and caffeine naïve individual’s lymphocyte counts, apoptosis and migration levels. In addition, effects of exercise on post-caffeine ingestion lymphocyte counts, apoptosis and migration levels were determined. It was hypothesized that caffeine would alter the immune system cell counts, but that exercise would be able to restore the immune system to homeostasis. Seventeen Western Kentucky University students were tested (males n=7, females n=10; n=7: caffeine tolerant= 200mg or more per day group, n=9: caffeine naïve= 50mg or less per day group). In this double-blind investigation, all participants completed two exercise bouts: 30 min of treadmill running at 60-80% HRR once with a placebo drink before exercise and once with 6 mg/kg body weight of caffeine drink completed in a counterbalanced manner. Blood was taken at rest, 30 min after drink ingestion, immediately post exercise, and 60 min post exercise. Blood was stained with antibody markers (Annexin V to determine apoptotic cell counts, CX3CR1 to determine cell migration, CD4=helper T cells, CD8=cytotoxic T cells, CD19=B cells). Blood was analyzed using flow cytometry. We found that cytotoxic T cells showed significant increases following the caffeinated run in both groups combined (tolerant and naïve, p=0.001) and specifically in the naïve group on the caffeine run (p=.004). We did not see any significant changes in CD4, or CD19 cell counts. There were no significant changes in CD4, CD8 or CD19 cell migration or apoptosis. Our results showed that caffeine supplementation causes an increased effect on cytotoxic T cells counts when combined with exercise, and this effect was greater for the caffeine naïve group. The combined effects of caffeine and exercise may have elevated the plasma catecholamine and cortisol levels which are associated with immune cell function and movement. CD8 cells have a greater density of β-receptors, which are influenced by catecholamine, and may explain the increase in their cell counts compared to CD4 and CD19.
3

The Effects Of Early Postnatal Ethanol Intoxication On Retina Ganglion Cell Morphology And The Development Of Retino-geniculate Projections In Mice

Dursun, Ilknur 01 February 2010 (has links) (PDF)
Experimental and clinical data have documented the adverse effects of perinatal ethanol intoxication on peripheral organs and the central nervous system. There is little known, however, about potential damaging effects of perinatal ethanol on the developing visual system. The purpose of this study was to examine the effects of neonatal ethanol intoxication on RGC morphology, estimate the total number of neurons in RGC layer and dorsolateral geniculate nucleus (dLGN), and on the eye-specific fiber segregation in the dLGN), in YFP and C57BL/6 mice pups. Ethanol (3 g/kg/day) was administered by intragastric intubation throughout postnatal days (PD) 3-20 or 3-10. Intubation control (IC) and untreated control (C) groups were included. Blood alcohol concentration (BAC) was measured in separate groups of pups on PD3, PD10, and PD20 at 4 different time points, 1, 1.5, 2 and 3 h after the second intubation. Numbers neurons in the RGCs and dLGN were quantified on PD10, PD20 using unbiased stereological procedures. The RGC images were taken using a confocal microscope and images were traced using Neurolucida software. On PD9, intraocular injections of cholera toxin-
4

Faktory ovlivňující počet somatických buněk v mléce vybraných chovů dojnic / Factors influencing somatic cell count in the milk of selected dairy cow breeds

VÍTOVÁ, Dagmar January 2011 (has links)
The objective of my study was to analyse the influence of selected factors in relation to somatic cell counts (SCC) in bulk milk samples of raw cow´s milk. Milk samples were tested in eight cowsheds with different technology of breeding and milking for a period of three years. The SCC values were determined by the Fluoro-opto-electronic method using the apparatus Fossomatic. A significant factor influencing the SCC was the season. The highest average values of the SCC were found in the summer months. The lowest average values of the SCC were determined in the loose bedded cubicle housing (250.103.ml-1), while the difference in the SCC compared to the loose bedding-free slatted floor housing (SCC average 317.103.ml-1) was highly statistically significant (p < 0,001). In the tie stall with bedding was the SCC average 292.103.ml-1. A highly statistically significant difference in the SCC (p < 0,001) was also demonstrated between breeds in the milking parlour (SCC average 265.103.ml-1) and breeds in the milking stall in the pipeline systems (SCC average 292.103.ml-1). It also showed a statistically highly significant difference in the SCC (p < 0,001) between breeds dominated by the Holstein breed cows (SCC average 285.103.ml-1) and breeds with breed prevalence of the Czech Fleckvieh cows (SCC average 265.103.ml-1). The level of yield was also affected by the SCC. There was no statistically significant difference among the farms using grazing and breeding without any possibility of keeping cows on pasture.
5

Impact d’une infection intra-mammaire causée par Staphylococcus aureus ou un staphylocoque coagulase-négative présente en début de lactation chez les taures laitières

Paradis, Marie-Ève 11 1900 (has links)
L’objectif de cette étude était de déterminer l’impact d’une infection intra-mammaire (IIM) subclinique causée par staphylocoque coagulase-négative (SCN) ou Staphylococcus aureus diagnostiquée durant le premier mois de lactation chez les taures sur le comptage de cellules somatiques (CCS), la production laitière et le risque de réforme durant la lactation en cours. Des données bactériologiques provenant d’échantillons de lait composites de 2 273 taures Holstein parmi 50 troupeaux ont été interprétées selon les recommandations du National Mastitis Council. Parmi 1 691 taures rencontrant les critères de sélection, 90 (5%) étaient positives à S. aureus, 168 (10%) étaient positives à SCN et 153 (9%) étaient négatives (aucun agent pathogène isolé). Le CCS transformé en logarithme népérien (lnCCS) a été modélisé via une régression linéaire avec le troupeau comme effet aléatoire. Le lnCCS chez les groupes S. aureus et SCN était significativement plus élevé que dans le groupe témoin de 40 à 300 jours en lait (JEL) (P < 0.0001 pour tous les contrastes). La valeur journalière du lnSCC chez les groupes S. aureus et SCN était en moyenne 1.2 et 0.6 plus élevé que le groupe témoin respectivement. Un modèle similaire a été réalisé pour la production laitière avec l’âge au vêlage, le trait génétique lié aux parents pour la production laitière et le logarithme népérien du JEL de la pesée inclus. La production laitière n’était pas statistiquement différente entre les 3 groupes de culture de 40 à 300 JEL (P ≥ 0.12). Les modèles de survie de Cox ont révélé que le risque de réforme n’était pas statistiquement différent entre le groupe S. aureus ou SCN et le groupe témoin (P ≥ 0.16). La prévention des IIM causées par SCN et S. aureus en début de lactation demeure importante étant donné leur association avec le CCS durant la lactation en cours. / The objective of this study was to determine the effect of a subclinical intramammary infection (IMI) caused by coagulase-negative staphylococci (CNS) or Staphylococcus aureus diagnosed during the first month of lactation in heifers on somatic cell count (SCC), milk production and culling risk during the entire first lactation. Bacteriological analysis data of composite milk samples taken from 2,273 Hostein heifers among 50 dairy herds were interpreted according to the National Mastitis Council guidelines. Among the 1,691 heifers meeting the selection criteria, 90 (5%) were diagnosed with S. aureus, 168 (10%) with CNS, and 153 (9%) were negative (no pathogen isolated). Test-day SCC transformed in natural logarithm (lnCCS) was fit in a linear regression model with herd as random effect. The lnSCC in S. aureus and CNS groups were significantly higher than in negative group from 40 to 300 days in milk (DIM) (P < 0.0001 for all contrasts). At test-day level, lnSCC in S. aureus and CNS groups was on average 1.2 and 0.6 higher than the negative group respectively. A similar model was used for milk yield with age at calving, parent average genetic value for milk yield and natural logarithm of tested DIM included. Milk yield was not statistically different between culture groups from 40 to 300 DIM (P ≥ 0.12). Compared with negative heifers, the culling hazard ratio estimated using Cox survival analysis in S. aureus and CNS infected heifers was not significant (P ≥ 0.16). Prevention of CNS or S. aureus IMI in early lactation remains important for its association with SCC during the ensuing lactation.
6

Impact d’une infection intra-mammaire causée par Staphylococcus aureus ou un staphylocoque coagulase-négative présente en début de lactation chez les taures laitières

Paradis, Marie-Ève 11 1900 (has links)
L’objectif de cette étude était de déterminer l’impact d’une infection intra-mammaire (IIM) subclinique causée par staphylocoque coagulase-négative (SCN) ou Staphylococcus aureus diagnostiquée durant le premier mois de lactation chez les taures sur le comptage de cellules somatiques (CCS), la production laitière et le risque de réforme durant la lactation en cours. Des données bactériologiques provenant d’échantillons de lait composites de 2 273 taures Holstein parmi 50 troupeaux ont été interprétées selon les recommandations du National Mastitis Council. Parmi 1 691 taures rencontrant les critères de sélection, 90 (5%) étaient positives à S. aureus, 168 (10%) étaient positives à SCN et 153 (9%) étaient négatives (aucun agent pathogène isolé). Le CCS transformé en logarithme népérien (lnCCS) a été modélisé via une régression linéaire avec le troupeau comme effet aléatoire. Le lnCCS chez les groupes S. aureus et SCN était significativement plus élevé que dans le groupe témoin de 40 à 300 jours en lait (JEL) (P < 0.0001 pour tous les contrastes). La valeur journalière du lnSCC chez les groupes S. aureus et SCN était en moyenne 1.2 et 0.6 plus élevé que le groupe témoin respectivement. Un modèle similaire a été réalisé pour la production laitière avec l’âge au vêlage, le trait génétique lié aux parents pour la production laitière et le logarithme népérien du JEL de la pesée inclus. La production laitière n’était pas statistiquement différente entre les 3 groupes de culture de 40 à 300 JEL (P ≥ 0.12). Les modèles de survie de Cox ont révélé que le risque de réforme n’était pas statistiquement différent entre le groupe S. aureus ou SCN et le groupe témoin (P ≥ 0.16). La prévention des IIM causées par SCN et S. aureus en début de lactation demeure importante étant donné leur association avec le CCS durant la lactation en cours. / The objective of this study was to determine the effect of a subclinical intramammary infection (IMI) caused by coagulase-negative staphylococci (CNS) or Staphylococcus aureus diagnosed during the first month of lactation in heifers on somatic cell count (SCC), milk production and culling risk during the entire first lactation. Bacteriological analysis data of composite milk samples taken from 2,273 Hostein heifers among 50 dairy herds were interpreted according to the National Mastitis Council guidelines. Among the 1,691 heifers meeting the selection criteria, 90 (5%) were diagnosed with S. aureus, 168 (10%) with CNS, and 153 (9%) were negative (no pathogen isolated). Test-day SCC transformed in natural logarithm (lnCCS) was fit in a linear regression model with herd as random effect. The lnSCC in S. aureus and CNS groups were significantly higher than in negative group from 40 to 300 days in milk (DIM) (P < 0.0001 for all contrasts). At test-day level, lnSCC in S. aureus and CNS groups was on average 1.2 and 0.6 higher than the negative group respectively. A similar model was used for milk yield with age at calving, parent average genetic value for milk yield and natural logarithm of tested DIM included. Milk yield was not statistically different between culture groups from 40 to 300 DIM (P ≥ 0.12). Compared with negative heifers, the culling hazard ratio estimated using Cox survival analysis in S. aureus and CNS infected heifers was not significant (P ≥ 0.16). Prevention of CNS or S. aureus IMI in early lactation remains important for its association with SCC during the ensuing lactation.
7

Factors influencing treatment adherence among adult patients receiving antiretroviral therapy at Extension 15 clinic, Gaborone, Botswana

Ndubuka, Nnamdi Obioma 11 1900 (has links)
This study analysed data obtained from respondents and their medical records to determine the barriers and motivators for good adherence to ART. Respondents' records were also reviewed together with their pharmacy refill records to identify any correlation between .CD4 cell counts, viral load, VL and adherence to antiretroviral drugs at extension 15 ARV clinic in Gaborone, Botswana. The study investigated whether the combination of pharmacy refills and pill counts adherence measurement methodologies could predict immunological recovery and virologic response through increased CD4 cell counts and suppressed VL. . There was a positive relationship between adherence, CD4 cell counts and VL. Pharmacy refills and pill counts adherence measurement methodologies scored high on sensitivity, specificity, and positive predictive values but low on negative predictive values. / Health Studies / M.A. (Public Health)
8

Correlation between CD4 counts and adherence to antiretrovirals in treatment patience at Katutura intermediate hospital, Windhoek, Namibia

Tjipura, Dinah Jorokee 04 1900 (has links)
The study analysed and compared data from patients' medical and pharmacy refill records to identify correlations between CD4 cell counts and adherence to antiretroviral drugs at Katutura Intermediate Hospital (KIH) in Windhoek, Namibia. The study investigated whether the pharmacy refill adherence measurement methodology could predict immunological recovery through increased CD4 cell counts. There was a positive but weak relationship between adherence and CD4 cell counts. Although the pharmacy refill records could predict immunological response it was not sensitive enough and should be used in combination with other adherence measurement tools. / Public Health / M.A. (Public Health)
9

Pharmacy refills as a measure of adherence to antiretroviral therapy for HIV positive patients at Mpilo Central Hospital in Bulawayo Zimbabwe

Mutasa, Kuda 28 October 2015 (has links)
This non-experimental, retrospective, descriptive and correlational study investigated adherence to antiretroviral drugs among HIV positive patients at Mpilo Central Hospital in Bulawayo Zimbabwe. Data among 118 patients was extracted from clinic registers and patient facility held medical records to determine level of adherence to ART using pharmacy refills (a non-immunological adherence parameter) and compared to CD4 cell count ( an immunological adherence parameter). Adherence levels obtained in this study using pharmacy refills was low (62.7%) and a relatively high non-adherence level of 37.3%. The pharmacy refill adherence level obtained was comparable to CD4 cell count adherence level of 64.6% (as indicated by a 50% CD4 cell count gain). These findings would seem to indicate the need for more education on the importance of adherence and further the need for better adherence monitoring systems / Health Studies / M.A. (Public Health)
10

Factors affecting highly active anti-retroviral therapy adherence in a rural area in Botswana

Tshisuyi, Emmanuel Tshibanda 24 October 2013 (has links)
The purpose of this study was to determine factors affecting non-adherence to Anti-retroviral therapy among AIDS patients. A cross sectional quantitative survey, was used. Structured interviews were conducted with 300 ART patients. Data were analysed using SPSS version 13 and presented in charts, graphs and frequency tables. Motivators of good adherence were identified as disclosure of HIV positive status to more than one person, frequent adherence counselling, self-efficacy to adhere to ART, positive interactions between patients and healthcare providers; and using an adherence partner. Barriers to adherence were forgetfulness, transportation costs to and from the clinic, time away from work and side effects. There was a strong positive correlation between adherence, CD4 counts and viral load. Adherence was closely tied to immunologic and virologic improvements. Respondents with poor adherence were likely to have unsuppressed viral loads (OR 12.98, 95%, CI 4.9-34). / Health Studies / Masters of Public Health

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