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Inter and intra-laboratory variability of CD4 : a pragmatic analysisMlawanda, Ganizani 29 July 2011 (has links)
Background: Measuring CD4 levels is the key laboratory investigation for decision making when initiating HAART, a tertiary prevention measure to reduce HIV/AIDS mortality and morbidity. Inherent biological and analytical variability is common during CD4 enumeration. We cannot control biological variation but how significant is analytical variation to clinical decision making. Objectives: To quantify inter and intra laboratories analytical variation of CD4 counts and percentages and to determine the degree to which time lapse after sample collection contributes to the analytical coefficient of variation (CV%).To estimate the extent of disease misclassification due to CD4 variability if CD4 < 350cells/mm3. Setting: This study was conducted at the HIV clinics of RSSC Hospital, a sugar-cane estate health institution located on the north-east of Swaziland, in Lubombo district, the worst affected by HIV/AIDS in Swaziland. The laboratories involved were Lancet, Good Shepherd (GSH) and National Reference (NRL) laboratories. Study design and method: An analytical diagnostic, cross-sectional (observational) study was used in this study. Using a convenience sampling technique and after obtaining consent from participants, blood was collected in EDTA tubes and sub-divided into three samples, each for Lancet, GSH and NRL. The samples were further split into two at each respective laboratory, one of which was run at 12hours and the other at 24hours from the time of sample collection. Main outcome measures: Student t-test; analytical coefficient of variation (CV%); Bland and Altman (BA) method bias and limits of confidence; BA plots and percentage difference plots; concordance correlation, Pearson and Kappa coefficients; McNemar test for comparison of paired proportion. Results: Fifty three participants consented for participation and of these twenty eight participants were male. The mean CD4 was 373.4 cells/mm3 for Lancet, 395.9 cells/mm3 for NRL and 439.2 cells/mm3 for GSH and subsequent paired t-test revealed some inherent variability. The CV% for CD4 count was 3.5%, 8.4% and 20.1 whilst bias was 7.0, 13.5 and 8.2 for NRL, Lancet and GSH respectively. CD4% had even stronger CV% for all three laboratories. Inter-laboratory bias for Lancet/NRL was -31.5; -64.3 for Lancet/GSH and -38.2 for NRL/GSH at 12hours for CD4 count with only Lancet/GSH having a clinically interchangeable limit of agreement. At 24hours, the trends were similar, possibly confirming stability of CD4 between 12 and 24hours. An assessment of disease misclassification at HAART initiation threshold was performed. The agreement was 81.1% for Lancet/NRL, 88.7% for Lancet/GSH and 77.4% for NRL/GSH corresponding to Kappa values of 0.64, 0.77 and 0.55 respectively. McNemar test for paired proportions revealed that there were no differences between the laboratories when it came to initiating HAART. Conclusions: whilst intra-laboratory variability is minimal, there is some significant inter-laboratory variation of CD4 count and CD4% at the laboratories used in Swaziland. Swaziland should ensure standard SOPs, on -going training and continuous quality improvements for all national laboratories and ensure standards are on par with international recommendations. The national HIV guidelines should possibly enforce two different CD4 counts in decision making to reduce systematic errors. Meanwhile, clinicians should continue to use their clinical judgment in cases of suspicious CD4 count results. / Dissertation (MSc)--University of Pretoria, 2011. / School of Health Systems and Public Health (SHSPH) / Unrestricted
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The blesser-blessee relationship : a pastoral challengeFrieslaar, Brent V. January 2019 (has links)
For many young women, life can be an overwhelming, stressful and challenging
experience. The increase in the cost of living and high costs of education places a
huge financial burden on the parents of these young women especially those who
are financially insecure and who have unfortunately not been awarded bursaries or
student loans. Many have to find means of income in order to fund their studies
and/or eke out a living. Older men who are wealthy have been found to take
advantage of these realities and they seek out young women who are struggling
financially and “bless” them by providing for their financial needs. Some older men
even go beyond these offerings and lavish the young women with other luxury items.
Young women see these men as caring and loving and also as a practical escape
from financial burdens they face. The older men, called “blessers’”, seek return on
their blessings and this is often in the form of sexual favours. The young women are
expected to satisfy the sexual desires of their blessers, often at great personal cost
and endless sacrifices. This exposes young women to sexual exploitation and
abuse.
This research seeks to gain a better understanding of the phenomenon and why
women engage in these relationships and why some remain in these relationships.
It also seeks to create awareness of the dangers of these relationships within the
context of the church and to empower young women with a healthy sense of selfworth
and value in order to make safer and informed life decisions and to pastorally
care for those who have experienced trauma. As a result of the understanding
gained through narrative approach, the researcher seeks to begin the process of
developing a pastoral care and healing methodology/intervention method. / Dissertation (MTh)--University of Pretoria, 2019. / Practical Theology / MTh / Unrestricted
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Assessing the Inter-Rater Reliability and Accuracy of Pharmacy Faculty's Bloom's Taxonomy ClassificationsKarpen, Samuel C., Welch, Adam C. 01 November 2016 (has links)
Objective To identify inter-rater reliability and accuracy of pharmacy faculty members' classification of exam questions based on Bloom's Taxonomy. Methods Faculty at a college of pharmacy was given six example exam questions to assign to the appropriate Bloom's level. Results Inter-rater reliability and accuracy were both low at 0.25 and 46.0%, respectively. Accuracy increased to 81.8% when the six Bloom's levels collapsed to three. Conclusions Both inter-rater reliability and accuracy were low. Faculty members' misclassifications suggested a three-tier combination of the Bloom's levels that would optimally improve accuracy: Knowledge, Comprehension/Application, and Analysis/Synthesis/Evaluation. Faculty development should also be considered in improving accuracy and reliability.
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Nonlinear Temporal Organization of Neuronal Discharge in the Basal Ganglia of Parkinson's Disease PatientsLim, Jongil, Sanghera, Manjit K., Darbin, Olivier, Stewart, R. M., Jankovic, Joseph, Simpson, Richard 01 August 2010 (has links)
Previous electrophysiological studies of the basal ganglia in Parkinson's disease (PD) patients have utilized linear analyses in time-or-frequency domains to characterize neuronal discharge patterns. However, these measures do not fully describe the non-linear features of discharge rates and oscillatory activities of basal ganglia neurons.In this original research, we investigate whether non-linear temporal organizations exist in the inter-spike interval series of neurons recorded in the globus pallidus or the subthalamic nucleus in PD patients undergoing surgery for the implantation of deep brain stimulating electrodes.Our data indicate that in approximately 80% of globus pallidus and subthalamic neurons, the raw inter-spike interval sequences have lower entropy values than those observed after shuffling of the original series. This is the first report establishing non-linear temporal organization as a common feature of neuronal discharge in the basal ganglia of PD patients.
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Inter-Area Oscillation Damping with Power System Stabilizers and Synchronized Phasor MeasurementsSnyder, Aaron Francis 10 February 1997 (has links)
Low frequency oscillations are detrimental to the goals of maximum power transfer and optimal power system security. A contemporary solution to this problem is the addition of power system stabilizers to the automatic voltage regulators on the generators in the power system. The damping provided by this additional stabilizer provides the means to reduce the inhibiting effects of the oscillations.
This thesis is an investigation of the use of synchronized phasor measurements as input signals for power system stabilizers installed on the generators of a two-area, 4-machine test power system. A remote measurement feedback controller has been designed and placed in the test power system. Synchronized phasor measurements from optimally sited measurement units were shown to improve the damping of low-frequency inter-area oscillations present in the test system when the proposed controller was included in the generator feedback control loop. The benefit of the damping of these oscillations was evident through the ability to increase the tie-line power flowing in the test system once the proposed control scheme was implemented. Time-domain simulations were used to verify the robustness of the proposed control during severe events, such as a short- circuit or sudden large variations of load. / Master of Science
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Bluetooth Frequency Hop Selection Kernel Impact on "Inter-Piconet" InterferenceBallagh, Jason 27 May 2003 (has links)
The Bluetooth wireless transmission standard provides a low-power data link between electronic devices over relatively short ranges. These links, also known as piconets, transmit using frequency hopping spread spectrum (FHSS) to send information over the air. As more applications for Bluetooth technology become available, the number of Bluetooth devices will continue to increase. With this increase in use, there will be a decrease in performance that can be attributed to Bluetooth "inter-piconet" interference. To date, very little has been published on the subject of inter-piconet interference. Previous studies have derived mean packet error rates for an increase in the number of piconets present. To come up with the mean rate, many papers make the assumption that the probability of a Bluetooth device hopping to a channel is random. However, making this assumption does not explain what happens in real time.
This research gives some insight into what really happens when multiple piconets are interfering in real time. Bluetooth devices actually use a frequency hopping algorithm to determine the hopping sequence. This algorithm has been implemented in software to test various aspects of inter-piconet interference. Previous studies have shown that synchronizing the clocks among neighboring piconets will result in an increase in performance. This study shows that there are cases where synchronization alone will not provide sufficient improvement. Experimental testing has been conducted to validate some of the simulated results. Adjacent channel interference was observed during experimentation. This contradicts previous research, which has assumed that adjacent channel interference is insignificant. / Master of Science
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Bumblebees, Fireflies & Ants at Coworking Spaces; Inter-organizational Collaboration Patterns within Coworking SpacesKhalighi, Pedram, Babatunde, Adekunle January 2018 (has links)
Coworking spaces, an example of the sharing economy concept, refers to shared workplaces that mostly freelancers, entrepreneurs and other actors of the knowledge industry utilize for the purpose of flexible sharing of space, ideas and knowledge. Previous research reveals that the proximity of occupants sitting together in a shared office space does not necessarily lead to inter-organizational collaboration. Knowledge sharing and inter-organizational collaboration tend to be perceived by occupants and managers of coworking spaces as incidental or a secondary aim. In the same view, coworking spaces tend to be perceived as service providers rather than a community where collaboration can be fostered. A potential solution, in this case is, the initial understanding and categorization of occupant types and their evident collaboration approaches which may result in the managers and policy makers of coworking spaces knowing what conditions to put in place in order to foster collaboration.The novelty of this research and contribution to theoretical knowledge lies in the development of insect metaphors to simplify the understanding of coworking space occupant types and their corresponding inter-organizational collaboration approaches as it affects their willingness or lack thereof to engage in collaboration.The research data was gathered through semi-structured interviews with a selection of occupants across three selective coworking spaces in Malmö. The findings of this research indicate that there are correlations between occupant types, their collaboration approach and their willingness to collaborate. Therefore, the effort to promote collaboration at coworking spaces needs to be a responsibility shared between the occupants and the community managers.
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Utilizing Legumes to Improve Production and Nutritive Value of Intermountain West PasturesBriscoe, Jacob T. 01 August 2018 (has links)
Pastures in the Intermountain Western United States mainly consist of cool-season grasses which lack production without supplemental nitrogen. Legumes provide nitrogen at reduced cost compared to nitrogen fertilizer. There is a need for proven methods of inter-seeding legumes into existing cool-season grass pastures as well as knowledge of how animals prefer legumes to grasses and how the nutritive value of forages change throughout the growing season. This research provides a resource for effective integration of legumes into pastures of the Intermountain West. Alfalfa, birdsfoot trefoil, and cicer milkvetch were inter-seeded into existing cool-season grass pastures following pretreatments of light tillage, mowing and glyphosate. Early spring and fall inter-seeding was unsuccessful, while late spring was moderately successful with overall alfalfa frequency of 30% after a year. Summer inter-seeding was the most successful with birdsfoot trefoil, alfalfa, and cicer milkvetch frequency of 42, 32, and 22%, respectively. In the animal preference study, when compared to tall fescue, birdsfoot trefoil was always utilized more.In most observations birdsfoot trefoil utilization was higher than orchard grass. While in all comparisons with meadow bromegrass there was no difference in utilization. During early growth, perennial ryegrass utilization was higher than birdsfoot trefoil utilization, but no difference in utilization was detected in later observations. Overall, birdsfoot trefoil was utilized 73% overall while grass utilization was 74, 67, 64, and 53% for perennial ryegrass, meadow bromegrass, orchardgrass and tall fescue, respectively. The interaction of growth stage and time of season on the nutritive value of alfalfa, birdsfoot trefoil, cicer milkvetch, orchardgrass, perennial ryegrass and tall fescue was determined. In the spring to early summer, legume nutritive value decreased rapidly with maturity, in midsummer the nutritive value decreased slowly with maturity, while in late summer the nutritive value remained stable. In the spring, grass nutritive value decreased rapidly, while in mid to late summer all grass regrowth was vegetative and the nutritive value remained stable. By inter-seeding in the summer, effectively managing mixed pastures, and utilizing forage at its highest nutritive value, legumes can benefit the pastures of the Intermountain West.
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Specification, estimation and testing of treatment effects in multinomial outcome models : accommodating endogeneity and inter-category covarianceTang, Shichao 18 June 2018 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / In this dissertation, a potential outcomes (PO) based framework is developed for
causally interpretable treatment effect parameters in the multinomial dependent variable
regression framework. The specification of the relevant data generating process (DGP) is
also derived. This new framework simultaneously accounts for the potential endogeneity
of the treatment and loosens inter-category covariance restrictions on the multinomial
outcome model (e.g., the independence from irrelevant alternatives restriction).
Corresponding consistent estimators for the “deep parameters” of the DGP and the
treatment effect parameters are developed and implemented (in Stata). A novel approach
is proposed for assessing the inter-category covariance flexibility afforded by a particular
multinomial modeling specification [e.g. multinomial logit (MNL), multinomial probit
(MNP), and nested multinomial logit (NMNL)] in the context of our general framework.
This assessment technique can serve as a useful tool for model selection. The new
modeling/estimation approach developed in this dissertation is quite general. I focus here,
however, on the NMNL model because, among the three modeling specifications under
consideration (MNL, MNP and NMNL), it is the only one that is both computationally
feasible and is relatively unrestrictive with regard to inter-category covariance. Moreover,
as a logical starting point, I restrict my analyses to the simplest version of the model – the
trinomial (three-category) NMNL with an endogenous treatment (ET) variable conditioned
on individual-specific covariates only. To identify potential computational issues and to assess the statistical accuracy of my proposed NMNL-ET estimator and its implementation
(in Stata), I conducted a thorough simulation analysis. I found that conventional
optimization techniques are, in this context, generally fraught with convergence problems.
To overcome this, I implement a systematic line search algorithm that successfully resolves
this issue. The simulation results suggest that it is important to accommodate both
endogeneity and inter-category covariance simultaneously in model design and estimation.
As an illustration and as a basis for comparing alternative parametric specifications with
respect to ease of implementation, computational efficiency and statistical performance,
the proposed model and estimation method are used to analyze the impact of substance
abuse/dependence on the employment status using the National Epidemiologic Survey on
Alcohol and Related Conditions (NESARC) data.
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Direct numerical simulation of charged colloids in an oscillating electric field / 振動電場下での荷電コロイド粒子の直接数値シミュレーションShih, Chun Yu 23 July 2015 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第19240号 / 工博第4075号 / 新制||工||1628(附属図書館) / 32239 / 京都大学大学院工学研究科化学工学専攻 / (主査)教授 山本 量一, 教授 宮原 稔, 教授 松坂 修二 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
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