The determinants of variation in firm leverage across European countries

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics

Sensitivity of Gomez-Nuñez boxes for the detection of household infestation with Panstrongylus megistus

Four methods for detecting household infestations with Panstrongylus megistus were compared: 1) manual collection; 2) collection after pyrethrum application; 3) search viable eggs; and 4) Gomez-Nuñez boxes. Manual collection was the most sensitive method (23% infested), followed by pyrethrum (21%), Gomez-Nuñez boxes (15%) and viable eggs (12%). About 10% of infested houses were positive exclusively on the Gomez-Nuñez box test. More over, 6 out of the 7 houses positive exclusively on the Gomez-Nuñez method were located in a recently sprayed area, where P. megistus density was low. Inspection of Gomez-Nuñez boxes at 12 weekspost-application was twice as effective as inspection at 6 weekspost-application. Triatomine feces was the most common evidencefor thepresence of P. megistus found within Gomez-Nuñez boxes. Gomez-Nuñez boxes area a useful adjunct to manual collection in detecting domestic infestations with P. megistus, especially in areas where bug densities are low. However, the utility of Gomez-Nuhez boxes must be weighed against the time and labor they require.

User-centered design of the interface prototype of a business intelligence mobile application

Dissertação para obtenção do Grau de Mestre em Engenharia e Gestão Industrial

Hemocultures for the parasitological diagnosis of human chronic Chagas' disease

With the purpose of standardization of an hemoculture technique presenting a higher positive rate in the parasitological diagnosis of chronic Chagas' disease in patients with reactive serology (IFT, HA, CFT) the following schedule was used. Thirty ml of venous blood was collected with heparin and the plasma was separated by centrifugation (2.000 rpm/30'). The packed cells were washed with LIT medium or PBS which was then removed by centrifugation (2.000 rpm/15'). This material was sampled in 6 screw-tubes 18x200 with 6 ml of LIT medium and incubated at 28°C. These incubated cultures at 28°C were examined after 15, 30, 45 and 60 days. When the hemoculture was not immediately processed after blood collection, the plasma was removed and the sediment enriched with LIT medium and preserved at 4°C. The Xenodiagnosis was performed according to Schenones method used here as a reference technique. Among the various groups of patients examined by both techniques the best results obtained were: 55.08% ofpositivity for hemocultures against 27.5% forxenodiagnosis (X² = 4.54, p = 0.05), with a tubepositivity of 26.6%. Recommendation for screening trials of drug assays is the repetition of method on a same patient 2 or more times in different occasions, as used in xenodiagnosis.

Gold nanoprobes for the detection of mutations associated with antibiotic resistance in Mycobacterium tuberculosis complex

Dissertação para obtenção do Grau de Mestre em Genética Molecular e Biomedicina

Comparison of the thick smear and Kato-Katz techniques for diagnosis of intestinal helminth infections

This study compared the efficiency of Kato-Katz thick smear and thick smear techniques for the diagnosis of intestinal helminths. The sensitivity of the thick smear technique was higher than that of the Kato-Katz method for the diagnosis of all helminths except Schistosoma mansoni.

2D position system for a mobile robot in unstructured environments

Nowadays, several sensors and mechanisms are available to estimate a mobile robot trajectory and location with respect to its surroundings. Usually absolute positioning mechanisms are the most accurate, but they also are the most expensive ones, and require pre installed equipment in the environment. Therefore, a system capable of measuring its motion and location within the environment (relative positioning) has been a research goal since the beginning of autonomous vehicles. With the increasing of the computational performance, computer vision has become faster and, therefore, became possible to incorporate it in a mobile robot. In visual odometry feature based approaches, the model estimation requires absence of feature association outliers for an accurate motion. Outliers rejection is a delicate process considering there is always a trade-off between speed and reliability of the system. This dissertation proposes an indoor 2D position system using Visual Odometry. The mobile robot has a camera pointed to the ceiling, for image analysis. As requirements, the ceiling and the oor (where the robot moves) must be planes. In the literature, RANSAC is a widely used method for outlier rejection. However, it might be slow in critical circumstances. Therefore, it is proposed a new algorithm that accelerates RANSAC, maintaining its reliability. The algorithm, called FMBF, consists on comparing image texture patterns between pictures, preserving the most similar ones. There are several types of comparisons, with different computational cost and reliability. FMBF manages those comparisons in order to optimize the trade-off between speed and reliability.

Intestinal protozoa and helminths among Terena Indians in the State of Mato Grosso do Sul: high prevalence of Blastocystis hominis

A parasitological survey was carried out among Terena Indians living in the Tereré settlement in the municipality of Sidrolândia, State of Mato Grosso do Sul, Brazil. Single samples of feces from 313 Indians were processed by means of the spontaneous sedimentation method. In the population studied, 73.5% were infected with at least one intestinal parasite or commensal. Protozoa predominated. Blastocystis hominis (40.9%), Entamoeba coli (33.2%) and Entamoeba histolytica/Entamoeba dispar (31.6%) were the most common. Bivariate analysis showed that females were generally more infected and presented higher rates of infection by Entamoeba histolytica/Entamoeba dispar and Entamoeba coli. Males were more infected by hookworms and Strongyloides stercoralis than females. The precarious sanitary conditions of the Tereré settlement are probably a contributory factor towards the high prevalence of intestinal protozoa.