Biometric Classification with Factor Analysis

This research presents a study on biometrics classification using Factor Analysis (FA). As a multivariate statistical tool, factor analysis is useful for understanding the underlying structure in a dataset. Moreover, in addition to achieving an economy of the variables, the"factors" or hypothetical constructs can provide an alternate yet succinct representation of the data. It is a method of determining, from an observable set of variables, a basic set of components that are common to all the observations. In this study, the loadings (orweights) on the Factors are used to classify the data in alternate representation. In particular, we will examine and group the data according to three biometric features. In the first part, we demonstrate the capabilities of factor analysis to capture the gender of the individual. This will enable us to use FA as a gender classifier. The next study will show the use of an FA as a facial hair classifier. Given a group of individuals, we will be able to classify them as either having beards or not. Finally, in the last part presented inthis work, we will work on classifying the facial expressions of a group of Japanese women. Given all seven universal expressions per subject (two or three of each expression), we will use factor analysis to group each subject according to their expression. Furthermore, given an individual with a particular expression, we will use factor analysis as a biometric measure in the determination of the particular expression exhibited

Dust exposure and chronic respiratory symptoms among coffee curing workers in Kilimanjaro: a cross sectional study

Background: Coffee processing causes organic dust exposure which may lead to development of respiratory symptoms. Previous studies have mainly focused on workers involved in roasting coffee in importing countries. This study was carried out to determine total dust exposure and respiratory health of workers in Tanzanian primary coffee-processing factories. Methods: A cross sectional study was conducted among 79 workers in two coffee factories, and among 73 control workers in a beverage factory. Personal samples of total dust (n = 45 from the coffee factories and n = 19 from the control factory) were collected throughout the working shift from the breathing zone of the workers. A questionnaire with modified questions from the American Thoracic Society questionnaire was used to assess chronic respiratory symptoms. Differences between groups were tested by using independent t-tests and Chi square tests. Poisson Regression Model was used to estimate prevalence ratio, adjusting for age, smoking, presence of previous lung diseases and years worked in dusty factories. Results: All participants were male. The coffee workers had a mean age of 40 years and were older than the controls (31 years). Personal total dust exposure in the coffee factories were significantly higher than in the control factory (geometric mean (GM) 1.23 mg/m³, geometric standard deviation (GSD) (0.8) vs. 0.21(2.4) mg/m³). Coffee workers had significantly higher prevalence than controls for cough with sputum (23% vs. 10%; Prevalence ratio (PR); 2.5, 95% CI 1.0 - 5.9) and chest tightness (27% vs. 13%; PR; 2.4, 95% CI 1.1 - 5.2). The prevalence of morning cough, cough with and without sputum for 4 days or more in a week was also higher among coffee workers than among controls. However, these differences were not statistically significant. Conclusion: Workers exposed to coffee dust reported more respiratory symptoms than did the controls. This might relate to their exposure to coffee dust. Interventions for reduction of dust levels and provision of respiratory protective equipment are recommended.publishedVersio

Lung functions among patients with pulmonary tuberculosis in Dar es Salaam – a cross-sectional study

Background Approximately 40–60 % of patients remain sufferers of sequela of obstructive, restrictive or mixed patterns of lung disease despite treatment for pulmonary tuberculosis (PTB). The prevalence of these abnormalities in Tanzania remains unknown. Methods A descriptive cross-sectional study was carried out among 501 patients with PTB who had completed at least 20 weeks of treatment. These underwent spirometry and their lung functions were classified as normal or abnormal (obstructive, restrictive or mixed). Logistic regression models were used to explore factors associated with abnormal lung functions. Results Abnormal lung functions were present in 371 (74 %) patients. There were 210 (42 %) patients with obstructive, 65 (13 %) patients with restrictive and 96 (19 %) patients with mixed patterns respectively. Significant factors associated with abnormal lung functions included recurrent PTB (Adj OR 2.8, CI 1.274 - 6.106), Human Immunodeficiency Virus (HIV) negative status (Adj OR 1.7, CI 1.055 - 2.583), age more than 40 years (Adj OR 1.7, CI 1.080 - 2.804) and male sex (Adj OR 1.7, CI 1.123 - 2.614). Conclusion The prevalence of abnormal lung functions is high and it is associated with male sex, age older than 40 years, recurrent PTB and HIV negative status

Lung functions among patients with pulmonary tuberculosis in Dar es Salaam – a cross-sectional study

Background Approximately 40–60 % of patients remain sufferers of sequela of obstructive, restrictive or mixed patterns of lung disease despite treatment for pulmonary tuberculosis (PTB). The prevalence of these abnormalities in Tanzania remains unknown. Methods A descriptive cross-sectional study was carried out among 501 patients with PTB who had completed at least 20 weeks of treatment. These underwent spirometry and their lung functions were classified as normal or abnormal (obstructive, restrictive or mixed). Logistic regression models were used to explore factors associated with abnormal lung functions. Results Abnormal lung functions were present in 371 (74 %) patients. There were 210 (42 %) patients with obstructive, 65 (13 %) patients with restrictive and 96 (19 %) patients with mixed patterns respectively. Significant factors associated with abnormal lung functions included recurrent PTB (Adj OR 2.8, CI 1.274 - 6.106), Human Immunodeficiency Virus (HIV) negative status (Adj OR 1.7, CI 1.055 - 2.583), age more than 40 years (Adj OR 1.7, CI 1.080 - 2.804) and male sex (Adj OR 1.7, CI 1.123 - 2.614). Conclusion The prevalence of abnormal lung functions is high and it is associated with male sex, age older than 40 years, recurrent PTB and HIV negative status

Understanding Household Behavioral Risk Factors for Diarrheal Disease in Dar es Salaam: A Photovoice Community Assessment

Whereas Tanzania has seen considerable improvements in water and sanitation infrastructure over the past 20 years, the country still faces high rates of childhood morbidity from diarrheal diseases. This study utilized a qualitative, cross-sectional, modified Photovoice method to capture daily activities of Dar es Salaam mothers. A total of 127 photographs from 13 households were examined, and 13 interviews were conducted with household mothers. The photographs and interviews revealed insufficient hand washing procedures, unsafe disposal of wastewater, uncovered household drinking water containers, a lack of water treatment prior to consumption, and inappropriate toilets for use by small children. The interviews revealed that mothers were aware and knowledgeable of the risks of certain household practices and understood safer alternatives, yet were restricted by the perceived impracticality and financial constraints to make changes. The results draw attention to the real economic and behavioral challenges faced in reducing the spread of disease

Status of Occupational Health and Safety and Related Challenges in Expanding Economy of Tanzania.

Occupational health and safety is related with economic activities undertaken in the country. As the economic activities grow and expand, occupational injuries and diseases are more likely to increase among workers in different sectors of economy such as agriculture, mining, transport, and manufacture. This may result in high occupational health and safety services demand, which might be difficult to meet by developing countries that are prioritizing economic expansion without regard to their impact on occupational health and safety. To describe the status of occupational health and safety in Tanzania and outline the challenges in provision of occupational health services under the state of an expanding economy. Tanzania's economy is growing steadily, with growth being driven by communications, transport, financial intermediation, construction, mining, agriculture, and manufacturing. Along with this growth, hazards emanating from work in all sectors of the economy have increased and varied. The workers exposed to these hazards suffer from illness and injuries and yet they are not provided with adequate occupational health services. Services are scanty and limited to a few enterprises that can afford it. Existing laws and regulations are not comprehensive enough to cover the entire population. Implementation of legislation is weak and does not protect the workers. Most Tanzanians are not covered by the occupational health and safety law and do not access occupational health services. Thus an occupational health and safety services strategy, backed by legislations and provided with the necessary resources (competent experts, financial and technological resources), is a necessity in Tanzania. The existing legal provisions require major modifications to meet international requirements and standards. OHS regulations and legislations need refocusing, revision, and strengthening to cover all working population. Capacities should be improved through training and research to enable enforcement. Finally the facilities and resources should be made available for OHS services to match with the growing economy

Personal Exposure to Dust and Endotoxin in Robusta and Arabica Coffee Processing Factories in Tanzania

Introduction: Endotoxin exposure associated with organic dust exposure has been studied in several industries. Coffee cherries that are dried directly after harvest may differ in dust and endotoxin emissions to those that are peeled and washed before drying. The aim of this study was to measure personal total dust and endotoxin levels and to evaluate their determinants of exposure in coffee processing factories. Methods: Using Sidekick Casella pumps at a flow rate of 2l/min, total dust levels were measured in the workers’ breathing zone throughout the shift. Endotoxin was analyzed using the kinetic chromogenic Limulus amebocyte lysate assay. Separate linear mixed-effects models were used to evaluate exposure determinants for dust and endotoxin. Results: Total dust and endotoxin exposure were significantly higher in Robusta than in Arabica coffee factories (geometric mean 3.41 mg/m³ and 10 800 EU/m3 versus 2.10 mg/m³ and 1400 EU/m³, respectively). Dry pre-processed coffee and differences in work tasks explained 30% of the total variance for total dust and 71% of the variance for endotoxin exposure. High exposure in Robusta processing is associated with the dry pre-processing method used after harvest. Conclusions: Dust and endotoxin exposure is high, in particular when processing dry preprocessed coffee. Minimization of dust emissions and use of efficient dust exhaust systems are important to prevent the development of respiratory system impairment in workers

Development and initial validation of questionnaire on predictors for the use of hearing protection devices among noise exposed manufacturing workers in Tanzania: A methodological study

Introduction: The use of hearing protection devices (HPDs) has been an intervention of choice in many workplaces such as in the construction industry for quite some time due to impractical effects of engineering and administrative interventions. Questionnaires for assessment for HPDs use among construction workers have been developed and validated in developed countries. However, there is limited knowledge of the same, among manufacturing workers in developing countries that are assumed to have a different culture, work organizations and production processes. Methods: We conducted a stepwise methodological study to develop a questionnaire to predict the use of HPDs among noise exposed workers in manufacturing factories in Tanzania. The questionnaire included 24 items and was developed through rigorous and systematic procedures involving three steps; (i) item formulation that involved two experts, (ii) expert content review and item rating that involving eight experts with vast experience in the field, and (iii) a field pre-test that involved 30 randomly selected workers from a factory with similar characteristics as a planned study site. A modified Pender's Health Promotion Model was adopted in the questionnaire development. We analyzed the questionnaire in terms of content validity and item reliability. Results: The 24 items were categorized into seven domains i.e., perceived self-efficacy, perceived susceptibility, perceived benefits, perceived barriers, interpersonal influences, situational influences and safety climate. The score for content validity for each item was satisfactory as the content validity index ranged between 0.75 to 1.00 for clarity, relevance, and essentiality criteria. Similarly, the scores for the content validity ratio (for all items) were 0.93, 0.88 and 0.93 for clarity, relevance, and essentiality, respectively. In addition, the overall value for Cronbach's alpha was 0.92 with domain coefficients: perceived self-efficacy 0.75; perceived susceptibility 0.74; perceived benefits 0.86; perceived barriers 0.82; interpersonal influences 0.79; situational influences; 0.70; and safety climate 0.79. The mean inter-item correlation was 0.49 suggesting good internal consistency. Discussion and conclusion: The developed and preliminary validated questionnaire can be used to predict the HPDs use among noise exposed manufacturing factory workers. Future surveys using this questionnaires warranted for further validation of the scale developed.publishedVersio