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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.
81

The teaching of mathematics in multigrade classrooms at the upper primary phase in selected Namibian schools

Kapenda, Loide Ndakondjelwa January 2011 (has links)
The Namibian curriculum favours knowledge with understanding and application of knowledge and skills, because facts that are learned with understanding are easier to remember. This made learners to be able to represent mathematical situations in different ways and for different purposes. It also motivates teachers to contextualise the content to make mathematics teaching and learning more interesting and enjoyable to teachers and learners. However, some mathematics teachers are challenged by being required to teach multigrade classes, due to a massive response to improved access to education.Multigrade teaching is seen as a difficult practice especially when teachers are not well prepared to teach combined grades. This case study focused on the teaching of mathematics at Upper Primary Phase. An Interpretive paradigm was used to understand the teachers’ experiences and their teaching ethods. Hence the study aimed to investigate how teachers deliver their mathematics lessons in multigrade classrooms, considering the good practices and challenges that may occur. The findings revealed that teachers mostly use their monograde pedagogical knowledge,resulting in using quasi-monograde with a common timetable approach when teaching mathematics in multigrade settings. Although learners have access to the common mathematics syllabus, the quality of teaching the subject in multigrade classrooms seems to be affected due to the lack of teacher training in multigrade teaching. Also, equity and democracy need to be considered more than it currently is in terms of resource distribution to multigrade schools. Good practice of multigrade teaching existed in building on lower grade competencies, introducing lessons with common activities, as well as the concentration on lower grades which make learners independent. However, insufficient time, lack of knowledge in multigrade and curriculum knowledge in particular seem to challenge teachers and learners. Therefore, multigrade teachers need to be part of curriculum development for them to master the syllabus. These teachers will assist in developing multigrade resources for integration, contextualisation and more enrichment activities for high achievers.
82

A COMBINATION THERAPY OF NICOTINAMIDE AND PROGESTERONE FOR FUNCTIONAL RECOVERY FOLLOWING TRAUMATIC BRAIN INJURY

Peterson, Todd 01 May 2013 (has links)
Traumatic Brain Injury (TBI) is a leading cause of death and disability in the United States for which there are no federally approved pharmacological treatments. Preclinical trials with nicotinamide (NAM) and progesterone (Prog) treatment demonstrate beneficial neuroprotection and recovery of function following TBI. The primary goal of this study was to assess both neuroprotection and recovery of function in an animal model of TBI after combination treatment of both NAM and Prog. Animals received a cortical contusion injury over the sensorimotor cortex and were treated with either nicotinamide (75 mg/kg, i.p. NAM loading dose, 12 mg/kg/hr NAM, s.c. over 72 hrs), Prog (10 mg/kg Prog, i.p. over 72 hrs), NAM and Prog(75 mg/kg, i.p. NAM loading dose, followed by continuous infusion of 12 mg/kg/hr NAM, s.c. over 72 hrs; 10 mg/kg Prog, i.p. over 72 hrs) or Vehicle (75 mg/kg, i.p. sterile saline loading dose, followed by continuous infusion 12 mg/kg/hr sterile saline, s.c. over 72 hrs; 10 mg/kg peanut oil, i.p. over 72 hrs), and compared to a craniotomy only (Sham) group. Following this regimen they were assessed in a battery of behavioral (fine and gross motor, sensory, and cognitive) tasks or a histological assessment at 24 hrs post-injury assessing lesion cavity size, degenerating neurons, and reactive astrocytes. Our results replicate the beneficial effects of treatment with either NAM or Prog demonstrating significant improvements in recovery of function, and a reduction in lesion cavitation, degenerating neurons and reactive astrocytes 24 hours post-injury. The combination treatment of NAM and Prog led to a significant improvement in both neuroprotection at 24 hrs post-injury and recovery of function in sensorimotor related tasks when compared to each individual treatment (NAM or Prog). It is suggested here that further preclinical trials using NAM and Prog as a combination treatment should be done to identify any drug interactions, pharmacokinetics, and a new window of opportunity and proper dosing of this combination treatment.
83

Curriculum delivery in multi-grade rural schools in the Breede River / Overberg EMDC

Faroo, David Joseph January 2009 (has links)
Thesis (DTech (Education))--Cape Peninsula University of Technology, 2009 / The phenomena of multi - grade schools has been absent both in educational policy making, educator training and only represented in a few local educational curriculum research projects. However, the practice of multi-grade is common in South Africa and especially in rural and farming South Africa. Our National Curriculum Statements implies that all schools are the same. This study addresses this anomaly. Farm schools, which started as a political means of cheap labour (Act 47 of 1953) presented a further complication to the ministry: public schools on private property govern by section 14 contract failed farm education (Forgotten Schools, 2004; Ministerial report on rural education, 2005; Commission on Human Rights, 2006). The political and ideological shift from People's Education, which, at first envision human rights in line with international treaties such Education For All, Convention on the right of the child, Africa Charter on the Rights of the Child to Human Capital Development has marginalize the farm and rural learner. Curriculum changes since Curriculum 2005 accepted the same political and economic vision. The first world technical National Curriculum Statements mismatch farm education as systemic results since 2004 has shown. The government’s deficit view and national curriculum influence farm and rural teaching and learning negatively. This study focuses on curriculum delivery (intended I implemented) planning. How the educator adapted the curriculum to suit the needs of third world farm learner, its multi-grade context and the ideology of the hegemony. The qualitative paradigm will be that of the critical theory and grounded theory methodology with the goal of uncovering the educators' views and practice. This has been done by holding interviews with various foundation phase educators and looking at the seating arrangements and planning. The sample was from the Breede River District. A focus group of nineteen ACE students with 312 collective years experience has been involved in the coding and analysing. Current practice and planning have been juxtaposed with international multi-grade practice. The research questions were aimed at uncovering how rural and farm educators plan for their multi-grade classes when faces with a national mono-grade curriculum. Various research methodologies were used.
84

"Combinação de classificadores simbólicos para melhorar o poder preditivo e descritivo de Ensembles" / Combination of symbolic classifiers to improve predictive and descriptive power of ensembles

Flávia Cristina Bernardini 17 May 2002 (has links)
A qualidade das hipóteses induzidas pelos atuais sistemas de Aprendizado de Máquina depende principalmente da quantidade e da qualidade dos atributos e exemplos utilizados no treinamento. Freqüentemente, resultados experimentais obtidos sobre grandes bases de dados, que possuem muitos atributos irrelevantes, resultam em hipóteses de baixa precisão. Por outro lado, muitos dos sistemas de aprendizado de máquina conhecidos não estão preparados para trabalhar com uma quantidade muito grande de exemplos. Assim, uma das áreas de pesquisa mais ativas em aprendizado de máquina tem girado em torno de técnicas que sejam capazes de ampliar a capacidade dos algoritmos de aprendizado para processar muitos exemplos de treinamento, atributos e classes. Para que conceitos sejam aprendidos a partir de grandes bases de dados utilizando Aprendizado de Máquina, pode-se utilizar duas abordagens. A primeira realiza uma seleção de exemplos e atributos mais relevantes, e a segunda ´e a abordagem de ensembles. Um ensemble ´e um conjunto de classificadores cujas decisões individuais são combinadas de alguma forma para classificar um novo caso. Ainda que ensembles classifiquem novos exemplos melhor que cada classificador individual, eles se comportam como caixas pretas, no sentido de n˜ao oferecer ao usuário alguma explicação relacionada à classificação por eles fornecida. O objetivo deste trabalho é propor uma forma de combinação de classificadores simbólicos, ou seja, classificadores induzidos por algoritmos de AM simbólicos, nos quais o conhecimento é descrito na forma de regras if-then ou equivalentes, para se trabalhar com grandes bases de dados. A nossa proposta é a seguinte: dada uma grande base de dados, divide-se esta base aleatoriamente em pequenas bases de tal forma que é viável fornecer essas bases de tamanho menor a um ou vários algoritmos de AM simbólicos. Logo após, as regras que constituem os classificadores induzidos por esses algoritmos são combinadas em um único classificador. Para analisar a viabilidade do objetivo proposto, foi implementado um sistema na linguagem de programação lógica Prolog, com a finalidade de (a) avaliar regras de conhecimento induzidas por algoritmos de Aprendizado de Máquina simbólico e (b) avaliar diversas formas de combinar classificadores simbólicos bem como explicar a classificação de novos exemplos realizada por um ensemble de classificares simbólicos. A finalidade (a) é implementada pelo Módulo de Análise de Regras e a finalidade (b) pelo Módulo de Combinação e Explicação. Esses módulos constituem os módulos principais do RuleSystem. Neste trabalho, são descritos os métodos de construção de ensembles e de combinação de classificadores encontrados na literatura, o projeto e a documentação do RuleSystem, a metodologia desenvolvida para documentar o sistema RuleSystem, a implementação do Módulo de Combinação e Explicação, objeto de estudo deste trabalho, e duas aplicações do Módulo de Combinação e Explicação. A primeira aplicação utilizou uma base de dados artificiais, a qual nos permitiu observar necessidades de modificações no Módulo de Combinação e Explicação. A segunda aplicação utilizou uma base de dados reais. / The hypothesis quality induced by current machine learning algorithms depends mainly on the quantity and quality of features and examples used in the training phase. Frequently, hypothesis with low precision are obtained in experiments using large databases with a large number of irrelevant features. Thus, one active research area in machine learning is to investigate techniques able to extend the capacity of machine learning algorithms to process a large number of examples, features and classes. To learn concepts from large databases using machine learning algorithms, two approaches can be used. The first approach is based on a selection of relevant features and examples, and the second one is the ensemble approach. An ensemble is a set of classifiers whose individual decisions are combined in some way to classify a new case. Although ensembles classify new examples better than each individual classifier, they behave like black-boxes, since they do not offer any explanation to the user about their classification. The purpose of this work is to consider a form of symbolic classifiers combination to work with large databases. Given a large database, it is equally divided randomly in small databases. These small databases are supplied to one or more symbolic machine learning algorithms. After that, the rules from the resulting classifiers are combined into one classifier. To analise the viability of this proposal, was implemented a system in logic programming language Prolog, called RuleSystem. This system has two purposes; the first one, implemented by the Rule Analises Module, is to evaluate rules induced by symbolic machine learning algorithms; the second one, implemented by the Combination and Explanation Module, is to evaluate several forms of combining symbolic classifiers as well as to explain ensembled classification of new examples. Both principal modules constitute the Rule System. This work describes ensemble construction methods and combination of classifiers methods found in the literature; the project and documentation of RuleSystem; the methodology developed to document the RuleSystem; and the implementation of the Combination and Explanation Module. Two different case studies using the Combination and Explanation Module are described. The first case study uses an artificial database. Through the use of this artificial database, it was possible to improve several of the heuristics used by the the Combination and Explanation Module. A real database was used in the second case study.
85

Perfil laboratorial bioquÃmico e hematolÃgico de uma populaÃÃo de pacientes diagnosticados com hansenÃase: antes e durante a poliquimioterapia

Maria Irismar da Silva Silveira 30 August 2007 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / A HansenÃase à uma doenÃa infecciosa, de evoluÃÃo lenta, transmitida pelo Mycobacterium leprae que acomete nervos e pele. O tratamento especÃfico das pessoas portadoras de hansenÃase foi enfatizado no inÃcio dos anos 80 pela OrganizaÃÃo Mundial de SaÃde (OMS) com o objetivo de curar o indivÃduo da infecÃÃo pelo Mycobacterium leprae e evitar o desenvolvimento de incapacidades. A OMS implementou a poliquimioterapia (PQT) composta pelas drogas dapsona, clofazimina e rifampicina, cuja associaÃÃo evita a resistÃncia medicamentosa do bacilo. A PQT mata o bacilo, evita a evoluÃÃo da doenÃa, e sendo realizada de forma completa e correta, garante a cura da doenÃa. O objetivo geral deste estudo foi avaliar parÃmetros laboratoriais antes e durante a PQT, em uma populaÃÃo de 102 pacientes hansÃnicos, com idade entre 5 e 78 anos, diagnosticados e assistidos no Centro de Dermatologia Dona LibÃnia (CDERM) no perÃodo de Janeiro de 2005 a Janeiro de 2006. Propomos um estudo para avaliaÃÃo da funÃÃo hepÃtica (TGO, TGP, Bilirrubinas Totais e fraÃÃes e Fosfatase Alcalina), renal (UrÃia e Creatinina) e parÃmetros hematolÃgicos (Leucograma, HematÃcrito e Hemoglobina). O estudo foi feito atravÃs da anÃlise laboratorial no soro do paciente para avaliaÃÃo da funÃÃo hepÃtica, renal e sangue total para parÃmetros hematolÃgicos. Destes, 50 (49%) pacientes foram classificados como paucibacilares (PB) e 52 (51%) multibacilares (MB). Teve como metodologia: ficha de investigaÃÃo, revisÃo de prontuÃrio e coleta de sangue antes de iniciar o tratamento e durante o tratamento, com 6 e 12 meses. Dentre os 102 pacientes estudados 48(47%) eram do sexo feminino e 54(53%) do sexo masculino, 12(11,7%) tinham 1 grau incompleto ou eram analfabetos e 6(5,8%) eram de nÃvel superior. Quanto à situaÃÃo financeira, 40(39,2%) nÃo possuÃam renda e 34(33,3%) ganhavam atà um salÃrio mÃnimo. A mÃdia da idade populacional foi de 40,8 anos (DP=19,3), entretanto a incidÃncia de pacientes com idade inferior a 10 anos foi maior no PB. Com relaÃÃo à forma clÃnica, 2(1,9%) eram da forma Indeterminada, 32(31,3%) TuberculÃide, 31(30,3%) Dimorfa, 15(14,7%) Dimorfa/TuberculÃide, 3(2,9%) Dimorfa/Virchowiana e 8(7,8%) da forma Virchowiana. Com relaÃÃo à anÃlise hematolÃgica, a anemia foi a alteraÃÃo mais freqÃente estando presente antes e durante o tratamento, tendo sido mais significativa no grupo MB no sexto mÃs de tratamento. No leucograma, linfocitose e eosinofilia foram as alteraÃÃes mais freqÃentes antes e durante a PQT nos dois grupos PB e MB. Em relaÃÃo aos parÃmetros bioquÃmicos, foram observadas alteraÃÃes nos nÃveis de TGO 6(5,8%) e TGP 5(4,9%) sem significÃncia estatÃstica. Considerando a inexistÃncia de um perfil laboratorial caracterÃstico para a hansenÃase, as alteraÃÃes encontradas em alguns parÃmetros durante a poliquimioterapia, nÃo podem ser atribuÃdas somente aos efeitos adversos deste esquema, e sim tambÃm aos efeitos inerentes à hansenÃase e/ou ao uso da PQT. Para a realizaÃÃo de um tratamento poliquimioterÃpico seguro à necessÃria a realizaÃÃo de exames laboratoriais antes e durante a poliquimioterapia / Leprosy or Hansenâs disease is an infectious disease with slow flow velocity, transmitted by Mycobacterium leprae that attacks nerves and skin. The specific treatment for people who suffer of leprosy was emphasized in the beginning of the 80âs by the World Health Organization (WHO) in order to cure the infection with Mycobacterium leprae and prevent disability. The WHO has implemented a multidrug therapy (MDT) composed of dapsone, rifampicin and clofazimine, an association that prevents bacillus resistance. The MDT kills the bacillus, prevents the aggravation of the disease, and if followed precisely, guarantees the cure of the disease. The objective of this study was to evaluate laboratory parameters, before and during the MDT, in a population of 102 hansenian patients, aged 5 to 78 years, diagnosed and assisted at the Center of Dermatology Dona LibÃnia (CDERM) between January 2005 and January 2006. Evaluation of liver function (GOT, GPT, total bilirubin and fractions and alkaline phosphatase), renal function (urea and creatinine) and haematological parameters (leukogram, hematocrit and hemoglobin) was done through blood serum analysis or patientâs clinical history. A review of patientâs medical records as well as blood tests was done before treatment, after 6 months and after one year. A total of 102 patients participated on the study. Fifty patients (49%) were classified as paucibacillary (PB) and 52 (51%) multibacillary (MB). Social-demographic characteristics showed that 48 (47%) were female and 54 (53%) were male; 12 (11.7%) were either illiterate or have not finished the first grade; 6 (5,8%) were graduating; 40 (39.2%) did not have income and 34 (33.3%) earned no more than the minimum wage. Mean age was 40,8 years (SD = 19,3) and the number of patients younger than 10 years was higher in PB. As to the clinical form, 32 patients (31.3%) presented the tuberculoid form, followed by dimorph (30.3%); dimorph / tuberculoid (14.7%); Virchowian (7.8%); dimorph / Virchowian (2.9%); and undetermined (1.9%). Hematological analysis showed that anemia was the most frequent alteration, being present before and during treatment, and was most significant in the group MB in the sixth month of treatment. The most frequent alterations showed in the leukogram before and during the MDT in both PB and MB groups were lymphocytosis and eosinophilia. Regarding to biochemical parameters, that changes in the levels of GOT (5.8%) and GPT (4.9%) without statistical significance. Considering the lack of a typical laboratory profile for leprosy, the changes found in some parameters during polychemotherapy can not be attributed only to adverse effects of this therapy but to other effects that are inherent to leprosy and the use of MDT. Therefore, a safe polychemotherapy requires the realization of laboratory tests before and during treatment
86

Combination of results from gene-finding programs

Hammar, Cecilia January 1999 (has links)
Gene-finding programs available over the Internet today are shown to be nothing more than guides to possible coding regions in the DNA. The programs often do incorrect predictions. The idea of combining a number of different gene-finding programs arised a couple of years ago. Murakami and Takagi (1998) published one of the first attempts to combine results from gene-finding programs built on different techniques (e.g. artificial neural networks and hidden Markov models). The simple combinations methods used by Murakami and Takagi (1998) indicated that the prediction accuracy could be improved by a combination of programs. In this project artificial neural networks are used to combine the results of the three well-known gene-finding programs GRAILII, FEXH, and GENSCAN. The results show a considerable increase in prediction accuracy compared to the best performing single program GENSCAN
87

Forecasting errors, directional accuracy and profitability of currency trading: The case of EUR/USD exchange rate

Costantini, Mauro, Crespo Cuaresma, Jesus, Hlouskova, Jaroslava January 2016 (has links) (PDF)
We provide a comprehensive study of out-of-sample forecasts for the EUR/USD exchange rate based on multivariate macroeconomic models and forecast combinations. We use profit maximization measures based on directional accuracy and trading strategies in addition to standard loss minimization measures. When comparing predictive accuracy and profit measures, data snooping bias free tests are used. The results indicate that forecast combinations, in particular those based on principal components of forecasts, help to improve over benchmark trading strategies, although the excess return per unit of deviation is limited.
88

Activating Transcription Factor 3 as a Regulator and Predictor of Cisplatin Response in Human Cancers

O'Brien, Anna January 2012 (has links)
Platinum-based chemotherapies are effective agents in the treatment of a wide variety of human cancers. However, patients with recurrent disease can become resistant to platinum-based chemotherapy, leading to low overall survival rates. Activating transcription factor 3 (ATF3) is a stress-inducible gene that is a regulator of cisplatin-induced cytotoxicity. ATF3 protein expression was upregulated after cytotoxic doses of cisplatin treatment in a panel of cell lines. A chromatin immunoprecipitation assay showed that upon treatment with cisplatin, ATF3 directly bound to the CHOP gene promoter and this correlated with an increase in CHOP protein expression. In a 1200 compound library screen performed on cancer cell lines, disulfiram, a dithiocarbamate drug, was identified as an enhancer of the cytotoxic effects of cisplatin. This increased cytotoxic action was likely due to disulfiram and cisplatin’s ability to induce ATF3 independently through two separate mechanisms, namely the MAPK and integrated stress pathways. Furthermore, ATF3 protein and mRNA levels were variable amongst human ovarian and lung cancer tissues, suggesting the potential for basal expression of ATF3 to be predictive of cisplatin treatment response. Thus, understanding ATF3’s role in cisplatin-induced cytotoxicity will lead to novel therapeutic approaches that could improve this drug’s efficacy.
89

Novel Combination Therapy: Monensin Potentiates Erlotinib-Induced Cytotoxicity

Khalil, Dayekh January 2013 (has links)
Receptor Tyrosine Kinase (RTK) inhibitors, such as erlotinib/tarceva, have been introduced in the past decade as a promising therapeutic option in Head and Neck Squamous Cell Carcinoma (HNSCC), however, they lack significant efficacy as single agents. As a result, RTK inhibitors require a combination based therapeutic approach with other treatment modalities. To uncover such a combination of agents, we performed a high throughput Prestwick library screen that included 1200 compounds approved by the FDA on HNSCC cell lines and found that monensin, a coccidial antibiotic, synergistically enhanced the cytotoxicity of erlotinib. RT-PCR revealed that monensin induced the expression of Activation of Transcription Factor (ATF) 3 and its downstream target C/EBP homologous protein (CHOP) which are key regulators of apoptosis. Furthermore, RNA-Seq analysis suggests that monensin augments erlotinib cytotoxicity by disturbing lipid and sterol biosynthesis. Therefore, identifying the mechanism of action exerted by monensin may open alternative avenues of cancer treatment.
90

Potential Distribution of an Electrical Source-Sink Combination Along the Axis of an Infinite Cylinder

Parish, Edward R. January 1953 (has links)
In the present paper, an attempt is made to obtain the potential distribution in the case of two such charges, a source-sink combination, located on the axis of a bore hole drilled through an infinite, homogeneous medium.

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