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1.
Public Health ; 165: 42-47, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30368167

RESUMO

OBJECTIVES: Cigarillo smoking has been associated with many adverse outcomes; however, little is known about its use in Canada. The aim of this study was to assess the prevalence and characteristics of ever and the current use of cigarillo in Canada. STUDY DESIGN: This study was a cross-sectional study. METHODS: This study was a secondary data analysis of the 2012 cycle of the Canadian Tobacco Use Monitoring Survey collected by Statistics Canada, examining tobacco use among Canadians aged 15 years or older in all 10 provinces. The two main outcomes of the present study were 'ever use' and 'current use' of cigarillos. Covariates examined included the following: demographic factors, socio-economic factors, and smoking-related factors. RESULTS: The overall prevalence of ever and current cigarillo smoking were 38.4% and 3.1%, respectively. Factors that had the highest association with cigarillo smoking included being a male and being young. Cigarette and marijuana use were also associated with increased use of cigarillo. Specifically, marijuana users were at two-fold increase of the current cigarillo smoking (odds ratio = 2.18, 95% confidence interval: 1.97-2.41). CONCLUSIONS: This study highlights the importance of correcting public perception about cigarillos and directing government resources to prevent an increase in their use.


Assuntos
Fumar/epidemiologia , Produtos do Tabaco/estatística & dados numéricos , Adolescente , Adulto , Canadá/epidemiologia , Estudos Transversais , Feminino , Inquéritos Epidemiológicos , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Adulto Jovem
2.
Parasit Vectors ; 7: 367, 2014 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-25127885

RESUMO

BACKGROUND: Despite the intensive global efforts to control intestinal parasitic infections, the prevalence of soil-transmitted helminth (STH) infections is still very high in many developing countries particularly among children in rural areas. METHODS: A randomized, double-blind, placebo-controlled trial was conducted on 250 Aboriginal schoolchildren in Malaysia to investigate the effects of a single high-dose of vitamin A supplementation (200,000 IU) on STH reinfection. The effect of the supplement was assessed at 3 and 6 months after receiving interventions; after a complete 3-day deworming course of 400 mg/daily of albendazole tablets. RESULTS: Almost all children (98.6%) were infected with at least one STH species. The overall prevalence of ascariasis, trichuriasis and hookworm infection was 67.8%, 95.5% and 13.4%, respectively. Reinfection rates of Ascaris, Trichuris and hookworm were high; at 6 months, assessment reached 80% of the prevalence reported before treatment. There were no significant differences in the reinfection rates and intensities of STH between vitamin A supplemented-children and those who received placebo at 3 and 6 months (p > 0.05). CONCLUSIONS: Vitamin A supplementation showed no protective effect against STH reinfection and this could be due to the high endemicity of STH in this community. Long-term interventions to reduce poverty will help significantly in reducing this continuing problem and there is no doubt that reducing intestinal parasitic infection would have a positive impact on the health, nutrition and education of these children. TRIAL REGISTRATION: This trial was registered at clinicaltrials.gov as NCT00936091.


Assuntos
Helmintíase/tratamento farmacológico , Helmintíase/prevenção & controle , Solo/parasitologia , Vitamina A/farmacologia , Albendazol/administração & dosagem , Albendazol/uso terapêutico , Anti-Helmínticos/administração & dosagem , Anti-Helmínticos/uso terapêutico , Criança , Suplementos Nutricionais , Relação Dose-Resposta a Droga , Feminino , Helmintíase/epidemiologia , Humanos , Malásia/epidemiologia , Masculino , Vitamina A/administração & dosagem
3.
Nutrients ; 6(1): 190-206, 2013 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-24384995

RESUMO

Iron deficiency anaemia (IDA) is the most common nutritional deficiency in the world including developed and developing countries. Despite intensive efforts to improve the quality of life of rural and aboriginal communities in Malaysia, anaemia and IDA are still major public health problems in these communities particularly among children. A randomized, double-blind, placebo-controlled trial was conducted on 250 Orang Asli (aboriginal) schoolchildren in Malaysia to investigate the effects of a single high-dose of vitamin A supplementation (200,000 IU) on iron status indices, anaemia and IDA status. The effect of the supplement was assessed after 3 months of receiving the supplements; after a complete 3-day deworming course of 400 mg/day of albendazole tablets. The prevalence of anaemia was found to be high: 48.5% (95% CI=42.3, 54.8). Moreover, 34% (95% CI=28.3, 40.2) of the children had IDA, which accounted for 70.1% of the anaemic cases. The findings showed that the reduction in serum ferritin level and the increments in haemoglobin, serum iron and transferrin saturation were found to be significant among children allocated to the vitamin A group compared to those allocated to the placebo group (p<0.01). Moreover, a significant reduction in the prevalence of IDA by almost 22% than prevalence at baseline was reported among children in the vitamin A group compared with only 2.3% reduction among children in the placebo group. In conclusion, vitamin A supplementation showed a significant impact on iron status indices and IDA among Orang Asli children. Hence, providing vitamin A supplementation and imparting the knowledge related to nutritious food should be considered in the efforts to improve the nutritional and health status of these children as a part of efforts to improve the quality of life in rural and aboriginal communities.


Assuntos
Anemia Ferropriva/tratamento farmacológico , Suplementos Nutricionais , Ferro da Dieta/administração & dosagem , Estado Nutricional , Vitamina A/administração & dosagem , Anemia Ferropriva/sangue , Anemia Ferropriva/epidemiologia , Criança , Estudos Transversais , Método Duplo-Cego , Ingestão de Energia , Feminino , Ferritinas/sangue , Hemoglobinas/metabolismo , Humanos , Ferro da Dieta/sangue , Malásia/epidemiologia , Masculino , Prevalência , Vitamina A/sangue
5.
Br J Nutr ; 106(7): 1100-6, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21492493

RESUMO

A community-based cross-sectional study was carried out among Aboriginal schoolchildren aged 7-12 years living in remote areas in Pos Betau, Pahang, Malaysia to investigate the potential determinants influencing the cognitive function and educational achievement of these children. Cognitive function was measured by intelligence quotient (IQ), while examination scores of selected school subjects were used in assessing educational achievement. Blood samples were collected to assess serum Fe status. All children were screened for soil-transmitted helminthes. Demographic and socio-economic data were collected using pre-tested questionnaires. Almost two-thirds (67·6 %) of the subjects had poor IQ and most of them (72·6 %) had insufficient educational achievement. Output of the stepwise multiple regression model showed that poor IQ was significantly associated with low household income which contributed the most to the regression variance (r2 0·059; P = 0·020). Low maternal education was also identified as a significant predictor of low IQ scores (r2 0·042; P = 0·043). With educational achievement, Fe-deficiency anaemia (IDA) was the only variable to show significant association (r2 0·025; P = 0·015). In conclusion, the cognitive function and educational achievement of Aboriginal schoolchildren are poor and influenced by household income, maternal education and IDA. Thus, effective and integrated measures to improve the nutritional and socio-economic status of rural children would have a pronounced positive effect on their education.


Assuntos
Fenômenos Fisiológicos da Nutrição Infantil , Cognição , Inteligência , Aprendizagem , Grupos Populacionais , População Rural , Criança , Estudos Transversais , Fezes/parasitologia , Feminino , Humanos , Malásia , Masculino , Distúrbios Nutricionais/psicologia , Inquéritos Nutricionais , Estado Nutricional , Doenças Parasitárias/epidemiologia , Fatores Socioeconômicos
6.
Am J Trop Med Hyg ; 83(3): 523-7, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20810815

RESUMO

A cross-sectional study was carried out on 241 primary schoolchildren in Pahang, Malaysia to update their vitamin A status and to investigate the association of poor vitamin A status with their health and socioeconomic factors. All children were screened for intestinal parasitic infections. Blood samples were collected and vitamin A status was assessed. Socioeconomic data were collected by using pre-tested questionnaires. The results showed that 66 (27.4%) children had low serum retinol levels (< 0.70 micromol/L). Giardiasis and severe ascariasis were significantly associated with low serum retinol levels (P = 0.004 and P = 0.018, respectively). Logistic regression confirmed the significant association of giardiasis with low serum retinol (odds ratio = 2.7, 95% confidence interval = 1.3-5.5). In conclusion, vitamin A deficiency is still a public health problem in rural Malaysia. Vitamin A supplementation and treatment of intestinal parasitic infections should be distributed periodically to these children to improve their health and nutritional status.


Assuntos
Giardíase/epidemiologia , População Rural , Deficiência de Vitamina A/epidemiologia , Criança , Feminino , Humanos , Malásia/epidemiologia , Masculino , Inquéritos e Questionários , Vitamina A/sangue
7.
Artigo em Inglês | MEDLINE | ID: mdl-19058591

RESUMO

A cross-sectional study was carried out to determine the current prevalence of protein-energy malnutrition (PEM) among Orang Asli schoolchildren and to investigate the potential predictors of malnutrition. A total of 241 (120 males and 121 females) Orang Asli schoolchildren age 7-12 years living in remote areas of Pos Betau, Pahang participated voluntarily in this study. Anthropometric and socioeconomic data were collected and the children were screened for intestinal parasitic infections. The overall prevalences of mild and significant underweight conditions were 52.3% and 37.3%, respectively, and the prevalences of mild stunting and wasting were 43.6% and 43.1%, respectively, while the prevalences of significant stunting and wasting were 43.6% and 5.6%, respectively. There was a significant association between gender (male) and malnutrition (p = 0.029). The results also showed a higher prevalence of stunting among children age < or = 10 years than in older children (p = 0.001). Other independent variables, including socioeconomic status and intestinal parasitic infections, had no significant associations with malnutrition indices. PEM is prevalent among schoolchildren in rural Malaysia and therefore of public health concern since PEM diminishes immune function and impairs cognitive function and educational performance. School-based programs of prevention through health education and interventions should be considered as an essential part of measures to improve the quality of life of schoolchildren in rural Malaysia.


Assuntos
Transtornos da Nutrição Infantil/epidemiologia , Desnutrição Proteico-Calórica/epidemiologia , Fatores Etários , Animais , Pesos e Medidas Corporais/estatística & dados numéricos , Criança , Estudos Transversais , Feminino , Humanos , Enteropatias Parasitárias/epidemiologia , Malásia/epidemiologia , Masculino , Prevalência , População Rural/estatística & dados numéricos , Fatores Sexuais , Fatores Socioeconômicos
8.
Trans R Soc Trop Med Hyg ; 102(10): 1046-52, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18617209

RESUMO

A cross-sectional study to determine the current prevalence of anaemia and iron deficiency anaemia (IDA) and to investigate the possible risk factors for IDA was carried out on 241 aboriginal schoolchildren (120 boys, 121 girls) aged 7-12 years and living in remote areas in Pos Betau, Pahang, Malaysia. Haemoglobin (Hb) level was measured and serum iron status was assessed by serum ferritin (SF), serum iron (SI) and total iron binding capacity measurements. Socioeconomic data were collected using pre-tested questionnaires. All children were screened for intestinal parasitic infections. Overall, 48.5% (95% CI 42.3-54.8) of children were anaemic (Hb<12 g/dl). The prevalence of IDA was 34% (95% CI 28.3-40.2), which accounted for 70.1% of the anaemia cases. The prevalence of IDA was significantly higher in females than males. Low levels of mothers' education and low household income were identified as risk factors for IDA. Severe trichuriasis also found to be associated with low SF and SI. Logistic regression confirmed low levels of mothers' education and gender as significant risk factors for IDA. Improvement of socioeconomic status and health education together with periodic mass deworming should be included in public health strategies for the control and prevention of anaemia and IDA in this population.


Assuntos
Anemia Ferropriva/epidemiologia , Ferritinas/sangue , Hemoglobinas/análise , Anemia Ferropriva/etnologia , Anemia Ferropriva/parasitologia , Ascaríase/epidemiologia , Ascaríase/etnologia , Criança , Estudos Transversais , Fezes/microbiologia , Fezes/parasitologia , Feminino , Humanos , Enteropatias Parasitárias/epidemiologia , Enteropatias Parasitárias/etnologia , Deficiências de Ferro , Modelos Logísticos , Malásia/epidemiologia , Malásia/etnologia , Masculino , Mães/educação , Prevalência , Fatores de Risco , Saúde da População Rural , Distribuição por Sexo , Fatores Socioeconômicos
9.
Acta Trop ; 107(2): 200-4, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18582430

RESUMO

Data on soil-transmitted helminth (STH) infections and reinfection among Orang Asli (aborigine) schoolchildren and their nutritional and socioeconomic status were analyzed to investigate the pattern and the possible predictors of STH reinfection. In this longitudinal study, 120 (60 males and 60 females) Orang Asli primary schoolchildren aged 7-12 years and living in remote areas in Pos Betau, Kuala Lipis, Pahang were screened for the presence of STH using modified cellophane thick smear and Harada Mori techniques. The overall prevalence of ascariasis, trichuriasis and hookworm infections were 65.8, 97.5 and 10.8%, respectively. After complete deworming with a 3-day course of 400mg/daily of albendazole tablets, children were re-examined at 3 and 6 months from baseline. The reinfection rate, by one or more of STH species, at 3 months after deworming was high (49.5%) while 79.6% of the children were reinfected at 6 months after deworming. Logistic regression analyses showed that females, stunted children and those living in houses without toilets had significantly higher reinfection rates than others at 3 months (P<0.05). At 6 months, maternal employment status emerged as another predictor where children of working mothers had significantly higher reinfection rates (P=0.026). In conclusion, reinfection rate of STH is high and thus necessitates frequent and periodic deworming among children. Public health personnel need to re-look at the current control measures and identify innovative and integrated ways in order to reduce STH significantly in the rural communities.


Assuntos
Helmintíase/epidemiologia , Helmintíase/transmissão , População Rural , Instituições Acadêmicas , Solo/parasitologia , Estudantes , Animais , Ascaríase/epidemiologia , Ascaríase/parasitologia , Ascaríase/transmissão , Ascaris lumbricoides/isolamento & purificação , Criança , Fezes/parasitologia , Feminino , Helmintíase/parasitologia , Infecções por Uncinaria/epidemiologia , Infecções por Uncinaria/parasitologia , Infecções por Uncinaria/transmissão , Humanos , Malásia/epidemiologia , Masculino , Contagem de Ovos de Parasitas , Valor Preditivo dos Testes , Recidiva , Tricuríase/epidemiologia , Tricuríase/parasitologia , Tricuríase/transmissão
10.
J Oral Sci ; 49(2): 161-6, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17634730

RESUMO

The purpose of this study was to investigate the antimicrobial efficacy of six groups of antibiotics and calcium hydroxide against Enterococcus faecalis biofilm in a membrane filter model. Two-day-old E. faecalis (ATCC 29212) biofilm was exposed to ampicillin, co-trimoxazole, erythr omycin, oxytetracycline, vancomycin, vancomycin followed by gentamicin, Ca(OH)(2), and phosphate-buffered saline (control). After 1 h of exposure, the antimicrobial activity was neutralized by washing each disc five times in PBS, and then the colony-forming units of the remaining viable bacteria on each disc were counted. The results revealed that only erythromycin, oxytetracycline and Ca(OH)2 showed 100% biofilm kill. An ANOVA with a Bonferroni post hoc test (P < 0.05) detected significant differences among the test agents, except in the ampicillin group versus the co-trimoxazole group. It is concluded that erythromycin, oxytetracycline and Ca(OH)2 are 100% effective in eliminating E. faecalis biofilm, whereas ampicillin, co-trimoxazole, vancomycin, and vancomycin followed by gentamicin are ineffective.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Hidróxido de Cálcio/farmacologia , Enterococcus faecalis/efeitos dos fármacos , Materiais Restauradores do Canal Radicular/farmacologia , Irrigantes do Canal Radicular/farmacologia , Contagem de Colônia Microbiana , Testes de Sensibilidade Microbiana
11.
Int J Impot Res ; 19(3): 321-5, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17136103

RESUMO

Premature ejaculation (PE) is a common sexual dysfunction among the general population. PE has often been associated with a psychological state of mind. Hospital Anxiety and Depression Scale (HADS) can be used as an instrument to assess the emotional and psychological state. The present study was designed to assess the reliability and validity of the HADS in a Malaysian population. The validity and reliability were studied in subjects with and without PE. Test-retest methodology was used to assess the reliability whereas Cronbach's alpha was used to assess the internal consistency. In the control and the PE groups, the internal consistency was good and a high degree of internal consistency was observed for all 14 items. In the control group, the Cronbach's alpha values at baseline were from 0.811 to 0.834, whereas for retest, the Cronbach's alpha values were from 0.821-0.838 items. Intraclass correlation coefficient (ICC) was high for the control (0.797-0.868: baseline and 0.805-0.872: retest) and PE group (0.822-0.906: baseline and 0.785-0.887: retest). The high value of ICC and the internal consistency was due to high reliability and consistency of the items at 2-week interval. A degree of significance between the baseline and week-2 scores was observed across all items in the PE group but not in the control group. The HADS is a suitable, reliable, valid and sensitive instrument to measure the clinical change for anxiety and depression in the Malaysian population.


Assuntos
Ansiedade/diagnóstico , Depressão/diagnóstico , Inventário de Personalidade/normas , Psicometria/normas , Disfunções Sexuais Fisiológicas/psicologia , Adulto , Ejaculação , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes
12.
Southeast Asian J Trop Med Public Health ; 38(6): 998-1007, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18613540

RESUMO

Despite great development in socioeconomic status throughout 50 years of independence, Malaysia is still plagued with soil-transmitted helminthiases (STH). STH continue to have a significant impact on public health particularly in rural communities. In order to determine the prevalence of STH among rural Orang Asli children and to investigate the possible risk factors affecting the pattern of this prevalence, fecal samples were collected from 292 Orang Asli primary schoolchildren (145 males and 147 females) age 7-12 years, from Pos Betau, Kuala Lipis, Pahang. The samples were examined by Kato-Katz and Harada Mori techniques. Socioeconomic data were collected using pre-tested questionnaires. The overall prevalence of ascariasis, trichuriasis, and hookworm infections were 67.8, 95.5 and 13.4%, respectively. Twenty-nine point eight percent of the children had heavy trichuriasis, while 22.3% had heavy ascariasis. Sixty-seven point seven percent of the children had mixed infections. Age > 10 years (p = 0.016), no toilet in the house (p = 0.012), working mother (p = 0.040), low household income (p = 0.033), and large family size (p = 0.028) were identified as risk factors for ascariasis. Logistic regression confirmed low income, no toilet in the house and working mother as significant risk factors for ascariasis. The prevalence of STH is still very high in rural Malaysian communities. STH may also contribute to other health problems such as micronutrient deficiencies, protein-energy malnutrition and poor educational achievement. Public health personnel need to reassess current control measures and identify innovative and integrated ways in order to reduce STH significantly in rural communities.


Assuntos
Helmintíase/transmissão , Enteropatias Parasitárias , População Rural , Microbiologia do Solo , Animais , Criança , Estudos Transversais , Feminino , Helmintíase/epidemiologia , Humanos , Malásia/epidemiologia , Masculino , Classe Social , Banheiros
13.
Health Promot Int ; 21(4): 301-10, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16963785

RESUMO

The worksite is one of the key channels for the delivery of interventions to reduce chronic diseases among adult populations. It provides easy and regular access to a relatively stable population and it encourages sustained peer support. This paper reports a 2-year follow-up of the impact of a worksite health promotion programme on serum cholesterol and dietary changes among employees in a city in Malaysia. A quasi-experimental study was conducted among Malay-Muslim male security guards, with those working in a public university in Kuala Lumpur comprising the intervention group, and those working in the teaching hospital of the same university as the comparison group. They were comparable in socio-demographic characteristics. The intervention group received intensive individual and group counselling on diet, physical activity and quitting smoking. The comparison group was given minimal education on the same lifestyle changes through mail and group counselling. The intervention group showed a statistically significant reduction in their mean total cholesterol levels as compared with the comparison group, with an intervention effect of -0.38 (95% CI = -0.63, -0.14) mmol/l. The intervention group also reported a reduction in the amount of cigarettes smoked. The worksite was shown to be an effective channel for health promotion. The adoption of the new lifestyle behaviours should be supported and sustained through modification of work policies.


Assuntos
Colesterol/sangue , Comportamentos Relacionados com a Saúde , Promoção da Saúde , Estilo de Vida , Serviços de Saúde do Trabalhador , Avaliação de Resultados em Cuidados de Saúde , Universidades/organização & administração , Local de Trabalho , Adulto , Aconselhamento , Diabetes Mellitus/epidemiologia , Diabetes Mellitus/terapia , Pesquisa sobre Serviços de Saúde , Humanos , Hipertensão/epidemiologia , Hipertensão/terapia , Malásia/epidemiologia , Masculino , Pessoa de Meia-Idade , Obesidade/epidemiologia , Obesidade/terapia , Educação de Pacientes como Assunto , Avaliação de Programas e Projetos de Saúde
14.
Med J Malaysia ; 58(2): 218-28, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-14569742

RESUMO

The role of husband-wife communication in the practice of family planning was studied among the rural Malay couples in Mukim Rusila, Terengganu. It was a cross-sectional study in which a cluster sampling was used to select the study sample. A total of 193 (100.0%) wives and 74 (38.3%) husbands responded to a face-to-face interview. Visual Analogue Scale was used to measure the level of husband-wife communication. Husband-wife communication score was lower on family planning compared to other matters. There was a significant fair agreement on the scores between the husbands and the wives (p > 0.05) on family planning. There was a significant association between husband-wife communication on family planning and the current practice of family planning (p = 0.002). The 'likelihood' that couples who had had good husband-wife communication to practice family planning was about 2.8 times higher compared to those couples with poor husband-wife communication (95% C.I.: 1.4, 5.3). Further research need to be carried out, as the study was limited by certain constraints.


Assuntos
Serviços de Planejamento Familiar , Relações Interpessoais , Casamento/etnologia , Adulto , Estudos Transversais , Feminino , Humanos , Malásia , Masculino
15.
Asia Pac J Public Health ; 15(2): 99-104, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-15038683

RESUMO

Body Mass Index (BMI) is the most established anthropometric indicator used for assessment of nutritional status. Other anthropometric indicators which are related closely to BMI are waist hip ratio (WHR) and waist circumference. In this paper, receiver operating characteristics (ROC) curves were constructed to assess the value of waist circumference and waist hip ratio as a screening measure for the need of weight management using BMI as the reference test. Sensitivity and specificity were calculated at several cut-offs. The areas under the ROC curve calculated by comparing waist circumference with BMI were high (0.70 - 0.86) while the areas calculated for WHR were low (0.46 - 0.67). Sensitivities of 0.745 and 0.800 were observed at cut-off points of waist circumference at 90cm and 80cm for males and females respectively, while the false positive rates were 0.233 for males and 0.250 for females. These cut-off points could be considered as a fair trade-off. Therefore it is concluded that waist circumference performed better than WHR as a screening test. It is indicative that waist circumference could be used as a tool in raising awareness of weight management in this population.


Assuntos
Peso Corporal , Pesos e Medidas Corporais , Índice de Massa Corporal , Feminino , Humanos , Masculino , Programas de Rastreamento/métodos , Obesidade/prevenção & controle , Curva ROC , Relação Cintura-Quadril
16.
IEEE Trans Neural Netw ; 13(3): 497-520, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-18244452

RESUMO

In this paper we consider two important topics: density estimation and random variate generation. We present a framework that is easily implemented using the familiar multilayer neural network. First, we develop two new methods for density estimation, a stochastic method and a related deterministic method. Both methods are based on approximating the distribution function, the density being obtained by differentiation. In the second part of the paper, we develop new random number generation methods. Our methods do not suffer from some of the restrictions of existing methods in that they can be used to generate numbers from any density provided that certain smoothness conditions are satisfied. One of our methods is based on an observed inverse relationship between the density estimation process and random number generation. We present two variants of this method, a stochastic, and a deterministic version. We propose a second method that is based on a novel control formulation of the problem, where a "controller network" is trained to shape a given density into the desired density. We justify the use of all the methods that we propose by providing theoretical convergence results. In particular, we prove that the L(infinity) convergence to the true density for both the density estimation and random variate generation techniques occurs at a rate O((log log N/N)((1-epsilon)/2)) where N is the number of data points and epsilon can be made arbitrarily small for sufficiently smooth target densities. This bound is very close to the optimally achievable convergence rate under similar smoothness conditions. Also, for comparison, the (2) root mean square (rms) convergence rate of a positive kernel density estimator is O(N(-2/5)) when the optimal kernel width is used. We present numerical simulations to illustrate the performance of the proposed density estimation and random variate generation methods. In addition, we present an extended introduction and bibliography that serves as an overview and reference for the practitioner.

17.
Med J Malaysia ; 57 Suppl E: 105-8, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12733204

RESUMO

Medical practice is changing, and the foundations of the paradigm shift lie in the development in research over the last four decades. Today, it is no longer adequate to treat a patient purely on clinical experience alone without a clear demonstration of evidence based on research, particularly the use of randomised controlled clinical trials. What is thought to be an effective mode of treatment currently may not necessarily hold true by the time medical students begin his/her medical practice. As a consequence, many medical schools worldwide are increasingly promoting evidence-based medicine (EBM) teaching in their medical curriculum along with problem-based learning (PBL). Teaching of EBM requires a paradigm shift in itself, as students must possess additional skills that are not traditionally part of medical training. These include the ability to acquire the skills in 'means of answering questions' than just 'knowing the answer to questions'. This paper aims to describe what EBM is and to highlight the formative experience of the teaching of EBM at the medical undergraduate level in the University of Malaya. Challenges and opportunities towards successful adoption of evidence-based practice are discussed.


Assuntos
Educação de Graduação em Medicina/normas , Medicina Baseada em Evidências/educação , Malásia
18.
Ann Acad Med Singap ; 30(4): 375-8, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11503543

RESUMO

INTRODUCTION: Encouraging teaching practices such as problem-based learning (PBL) amongst undergraduate students within a lecture-based, system-based integrated curriculum is a challenge. Students are apprehensive about developing an organised framework for acquiring knowledge while lecturers are required to reframe their views on the educational process and their role as educators. MATERIALS AND METHODS: Lecturers and students in the Phase (Year) II programme were asked to fill questionnaires following the second and fourth PBL cases. The two sets of survey responses were compared to see whether the students' and teachers' perceptions had changed over the 5-month period. RESULTS: Students' responses from both surveys (1 and 2) were similar in that a majority agreed that the PBL tutorials had encouraged the seeking of information (66% and 67%, respectively), had improved understanding (57% and 56%), integration (65% and 70%) and application (50% and 64%) of knowledge. However, the views given in the form of written comments, following their positive responses, were somewhat contradictory. A large number of students (38% and 40%) faced difficulties in getting involved in discussions during the PBL tutorial and a majority (73% and 82%) preferred the normal subject-based tutorials. The reasons given by approximately 20% of the students were that the subject-based tutorials were more efficient for obtaining information and/or that the information had been pre-selected by the lecturers. More than 80% of the lecturers (in both surveys) perceived that the students had identified the appropriate learning objectives and covered the subject matter. The percentage of lecturers who agreed that PBL tutorials encouraged rapport and teamwork amongst students had increased in the second survey, from 70% to 92% and 55% to 83% respectively. CONCLUSION: Implementing PBL is not simply a matter of developing new teaching materials and new effective ways of presenting them. It requires a paradigm shift, a change in the roles of students and teachers, and time.


Assuntos
Educação Médica , Aprendizagem Baseada em Problemas , Humanos , Avaliação de Programas e Projetos de Saúde , Estudantes de Medicina , Pensamento
19.
IEEE Trans Neural Netw ; 12(4): 929-35, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-18249923

RESUMO

The prediction of corporate bankruptcies is an important and widely studied topic since it can have significant impact on bank lending decisions and profitability. This work presents two contributions. First we review the topic of bankruptcy prediction, with emphasis on neural-network (NN) models. Second, we develop an NN bankruptcy prediction model. Inspired by one of the traditional credit risk models developed by Merton (1974), we propose novel indicators for the NN system. We show that the use of these indicators in addition to traditional financial ratio indicators provides a significant improvement in the (out-of-sample) prediction accuracy (from 81.46% to 85.5% for a three-year-ahead forecast).

20.
IEEE Trans Neural Netw ; 12(6): 1411-32, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-18249970

RESUMO

Practical algorithms are presented for adaptive state filtering in nonlinear dynamic systems when the state equations are unknown. The state equations are constructively approximated using neural networks. The algorithms presented are based on the two-step prediction-update approach of the Kalman filter. The proposed algorithms make minimal assumptions regarding the underlying nonlinear dynamics and their noise statistics. Non-adaptive and adaptive state filtering algorithms are presented with both off-line and online learning stages. The algorithms are implemented using feedforward and recurrent neural network and comparisons are presented. Furthermore, extended Kalman filters (EKFs) are developed and compared to the filter algorithms proposed. For one of the case studies, the EKF converges but results in higher state estimation errors that the equivalent neural filters. For another, more complex case study with unknown system dynamics and noise statistics, the developed EKFs do not converge. The off-line trained neural state filters converge quite rapidly and exhibit acceptable performance. Online training further enhances the estimation accuracy of the developed adaptive filters, effectively decoupling the eventual filter accuracy from the accuracy of the process model.

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