Efficacy of different vinegar solutions in removal of Candida albicans from denture acrylic resin

A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in partial fulfillment of the requirements for the degree of Msc (Dent) (OMP) Johannesburg,2018.Background and Aims: Denture hygiene has become an important aspect in managing patients who often present with signs of denture stomatitis associated with Candida infection. There is a need for denture disinfectants which are of low cost and are easily accessible to denture wearers. The aim of this study was to investigate the efficacy of different vinegar solutions in removal of C. albicans from denture acrylic resin. Materials and Methods: Hundred and ninety-two acrylic plates were used. White wine vinegar (6%), rice vinegar (5.5%), and apple cider vinegar (5%) were used as disinfectants. Distilled water and 0.2% Chlorhexidine were used as controls. Cultures of C. albicans ATCC 90028 and a HIV strains were grown in Saboraud’s dextrose agar. Sterile acrylic resin plates were immersed in test tubes and 200μl of C. albicans suspension was added to each tube. Contaminated acrylic plates were divided into 5 groups of 6 plates each. Plates were immersed in 20 ml of white wine vinegar (WWV), Rice vinegar (RV), Apple cider vinegar (ACV), sterile distilled H2O, and chlorhexidine (CHX). These were incubated at room temperature for 30minutes, 1 hour and 8hours. Two non-exposed plates were included as controls. Results: ACV, WWV and RV equally eliminated both C. albicans ATCC 90028 and HIV strains from acrylic plates at 8 hours (% Kill=100). All tested vinegars failed to completely eliminate C. albicans strains at 30 minutes and 1 hour, with no statistical significant difference for ATCC strain(p<0.05) and with statistical difference for ACV (p=0.03) and RV (p=0.01) respectively for HIV strain. CHX completely eliminated ATCC strain at all tested times (%=100), but failed to completely eliminate HIV strain at 30 minutes and 1 hour. Sterile water, a negative control failed to completely eliminate both C. albicans strains at all tested times. Conclusions: The results of the current study confirm that vinegar can be used to remove C. albicans from dentures, if used for 8 hours.LG201

La mediación en la contratación de seguros

El Anteproyecto de Ley del Código Mercantil de 2014 regula la mediación en la contratación de seguros desde una perspectiva parcial, abordando únicamente la actividad derivada de los contratos de mediación, ya sea en la modalidad de agencia ya sea en la de correduría de seguros. Dedicamos este trabajo al estudio, también, del aspecto subjetivo de tal actividad, el de los protagonistas de la mediación en seguros privados. Junto a su régimen general, aplicable tanto a la agencia como a la correduría, nos centramos en la especificidad de cada modalidad, tomando en consideración asimismo no sólo la relación contractual que les une a la entidad aseguradora (y en el caso del corredor, también al cliente) sino también la especialidad del agente de seguros con naturaleza crediticia (el operador de banca-seguros). Referencia destacada merece la doble posibilidad de vinculación contractual del agente de seguros (y del operador de banca-seguros) con una o varias entidades de seguros, con el calificativo añadido de exclusivo o vinculado, respectivamente

CITIDEL Collection Building

The aim of this study is to facilitate the goals of the Computing and Information Technology Interactive Digital Educational Library (CITIDEL) by increasing the number of collections available to it. This study will help in achieving this goal by focusing on four diverse collections

Bayes classifiers for imbalanced traffic accidents datasets

[EN] Traffic accidents data sets are usually imbalanced, where the number of instances classified under the killed or severe injuries class (minority) is much lower than those classified under the slight injuries class (majority). This, however, supposes a challenging problem for classification algorithms and may cause obtaining a model that well cover the slight injuries instances whereas the killed or severe injuries instances are misclassified frequently. Based on traffic accidents data collected on urban and suburban roads in Jordan for three years (2009-2011); three different data balancing techniques were used: under sampling which removes some instances of the majority class, oversampling which creates new instances of the minority class and a mix technique that combines both. In addition, different Bayes classifiers were compared for the different imbalanced and balanced data sets: Averaged One-Dependence Estimators, Weightily Average One-Dependence Estimators, and Bayesian networks in order to identify factors that affect the severity of an accident. The results indicated that using the balanced data sets, especially those created using oversampling techniques, with Bayesian networks improved classifying a traffic accident according to its severity and reduced the misclassification of killed and severe injuries instances. On the other hand, the following variables were found to contribute to the occurrence of a killed causality or a severe injury in a traffic accident: number of vehicles involved, accident pattern, number of directions, accident type, lighting, surface condition, and speed limit. This work, to the knowledge of the authors, is the first that aims at analyzing historical data records for traffic accidents occurring in Jordan and the first to apply balancing techniques to analyze injury severity of traffic accidents. (C) 2015 Elsevier Ltd. All rights reserved.The authors are grateful to the Police Traffic Department in Jordan for providing the data necessary for this research. Griselda Lopez wishes to express her acknowledgement to the regional ministry of Economy, Innovation and Science of the regional government of Andalusia (Spain) for their scholarship to train teachers and researchers in Deficit Areas, which has made this work possible. The authors appreciate the reviewers' comments and effort in order to improve the paper.Mujalli, R.; López-Maldonado, G.; Garach, L. (2016). Bayes classifiers for imbalanced traffic accidents datasets. Accident Analysis & Prevention. 88:37-51. https://doi.org/10.1016/j.aap.2015.12.003S37518

Auditor switching

Text in EnglishThis study explores the phenomenon of auditor switching. The purpose of this study is to further contribute to the auditor switching literature by examining the reasons client companies in South Africa switch auditors, where the topic has not previously been studied and following a period of rapid and significant change in the auditing profession. Using previous literature as a foundation, forty-four variables that contribute to auditor switching are presented and tested based on empirical data elicited by means of a questionnaire survey of sample companies that experienced auditor switching during the period 1 January 1998 to 30 June 1999 as obtained from Practitioners in the KwaZulu-Natal Region. The factors motivating auditor switching were based on a questionnaire response of seventy-five companies (response rate 67% ). The empirical study also tested whether or not the switch variables thus identified are statistically related to auditor switching. The findings of this study revealed that audit fees are both the most frequently cited reason for switching auditors and found to be statistically significant at the 0.05 level of significance. Dissatisfaction over the overall quality of services provided by the auditor, lack of communication including the lack of responsiveness to client needs, poor working relationship with audit partner followed as switch factors but were not found to be statistically significant at 0. 05 level. The findings of this study revealed that two other variables, namely, management change and the need for group auditor rationalisation, appear to be significantly related to auditor switching at the 0.05 1evel of significance.AuditingM. Comm. (Auditing

Which clinical parameters predict a CSF diagnosis of meningitis in a population with high HIV prevalence?

Background. The HIV epidemic has changed the aetiology of meningitis in sub-Saharan Africa, and frontline clinicians are faced with a variety of meningitic presentations. Doctors working in resource-limited settings have the challenge of appropriately selecting patients for lumbar puncture (LP), a potentially risky procedure that requires laboratory analysis.Methods. In a rural South African hospital, the practice of performing LPs was audited against local guidelines. Data were collected retrospectively between February and June 2013. Symptoms and signs of meningitis, HIV status, investigations performed prior to LP and cerebrospinal fluid (CSF) results were recorded. With the aim of determining statistically significantclinical predictors of meningitis, parameters were explored using univariate and multivariate logistic regression analyses.Results. A total of 107 patients were included, of whom 43% had an  abnormal CSF result. The majority (76%) of patients were HIV-positive (CD4+ cell count &lt;200 cells/ìl in 46%). Cryptococcal meningitis (CCM) was the most prevalent microbiological diagnosis, confirmed in 10 out of 12 patients. Of the non-microbiological diagnoses, lymphocytic predominance was the most common abnormality, present in 17 out of 33 patients. Confusion (p=0.011) was the most statistically significant predictor of anabnormal CSF result. Headache (p=0.355), fever (p=0.660) and  photophobia (p=0.634) were not statistically predictive.Conclusion. The high incidence of CCM correlates with previous data from sub-Saharan Africa. In populations with high HIV prevalence, the classic meningitic symptoms of headache, fever and photophobia, while common presenting symptoms, are significantly less predictive of a meningitis diagnosis than confusion

Rice vinegar removes Candida albicans from denture acrylic resins

Denture stomatitis, mainly caused by Candida albicans, often affect denture wearers. To manage these patients, denture hygiene is of utmost importance. There is a need for low cost, easily accessible denture disinfectants. To investigate the efficacy of rice vinegar and other disinfecting solutions in removing C. albicans from acrylic resins. Hundred and eighty acrylic resin plates were contaminated with C. albicans strains and divided into five groups. These were immersed in apple cider vinegar (ACV), white wine vinegar (WWV), rice vinegar (RV), chlorhexidine (CHX), and sterile distilled H2O (control). The plates were incubated at room temperature for 30 minutes, 1 hour and 8 hours. Candida removing ability of the disinfecting solutions was evaluated, and data was analyzed using two-way ANOVAwith Tukey post-test. Significance level of p&lt; 0.05 was used. RV, ACV, WWV and CHX showed the highest efficacy (100%) in removing both C. albicans strains at 8 hours (p&gt;0.05). CHX was the most effective disinfectant in removing both C. albicans strains at 30 minutes, 1 hour, and 8 hours (99%-100%). RV was as effective as ACV, WWV and CHX in removing C. albicans from acrylic plates at 8 hours

Robust phase sensitive inversion recovery imaging

Inversion Recovery (IR) is a powerful tool for contrast manipulation in Mag- netic Resonance Imaging (MRI). IR can provide strong contrast between tissues with different values of T1 relaxation times. The tissue magnetization stored at an IR image pixel can take positive as well as negative values. The corresponding polarity information is contained in the phase of the complex image. Due to numerous factors associated with the Magnetic Resonance (MR) scanner and the associated acquisition system, the acquired complex image is modulated by a spatially varying background phase which makes the retrieval of polarity information non-trivial. Many commercial MR scanners perform magnitude-only reconstruction which, due to loss of polarity information, reduces the dynamic contrast range. Phase sensitive IR (PSIR) can provide enhanced image contrast by estimating and removing the background phase and retrieving the correct polarity information. In this thesis, the background phase of complex MR image is modeled using a statistical model based on Markov Ran- dom Fields (MRF). Two model optimization methods have been developed. The first method is a computationally effcient algorithm for finding semi-optimal solutions satisfying the proposed model. Using an adaptive model neighborhood, it can recon- struct low SNR images with slow phase variations. The second method presents a region growing approach which can handle images with rapid phase variations. Ex- perimental results using computer simulations and in vivo experiments show that the proposed method is robust and can perform successful reconstruction even in adverse cases of low signal to noise ratios (SNRs) and high phase variations

Diseño de una Planta piloto para la separación de distintos componentes de la leche de vaca

[ES] Una de las proteínas más abundantes en la leche de vaca es la caseína, esta se puede aprovechar para muchos usos alimentarios conocidos(fabricación de queso,complementos alimentarios,etc.). La recuperación de la caseina como una fracción aislada, es relativamente sencilla, mediante su precipitación a diferentes condiciones. Como subproducto de este proceso de precipitación, se obtiene lactosuero que debido a que es altamente contaminante para el medio ambiente, requiere de un tratamiento específico en la instalación donde se genera.En numerosas ocasiones no es posible realizar este tratamiento in situ y esto genera un coste adicional al proceso.Por este motivo, se contempla la separación fraccionada de las distintas fracciones proteicas que contiene, para su posterior comercialización, por lo que haremos económicamente viable el proceso en todas sus etapas.[EN] One of the most abundant proteins in cow milk is casein, which can be used in the food industry to produce some types of cheese or food supplements. The recuperation of casein as an isolated fraction, is relatively easy, through its precipitation at certain conditions. As a byproduct of this precipitation process, whey is obtained. As the whey is relatively pollutant for the environment, it requires of specific treatments at the plant where it is generated. In numerous occasions, it is not posible to perform these treatments, making the entire process less viable. Because of this, we contemplate the separation of the different proteins it contains for a future sale, which would make the process much more viable in all its steps.[CAT/VA] Una de les proteïnes més abundants en la llet de vaca es la caseína: aquesta es pot aprofitar per a molts usos alimentaris coneguts com son la fabricació de formatges, complementes alimentaris, etc. La recuperació de la caseína como una fracció aïllada es relativament senzilla mitjanzant la seua precipitació a diferents condicios. Com subproducte d’aquest procés de precipitació s’obté el serum de la llet, que per ser altament contaminant per al medi ambient requereix un tractament especific en la instal·lació on es genera. En nombroses ocasiones no es posible realizar aquest tractament in situ i això genera un cost addicional al procés. Per aquest motiu, es contempla la separació fraccionada de les diferents fraccions proteiques que conté, per a una posterior comercialització, amb la qual cosa farem economicament viable el procés en totes les seus etapes.Garach Serrano, G. (2017). Diseño de una Planta piloto para la separación de distintos componentes de la leche de vaca. http://hdl.handle.net/10251/87868.TFG