DISPOSITION EFFECT AMONG BRAZILIAN EQUITY FUND MANAGERS

The disposition effect predicts that investors tend to sell winning stocks too soon and ride losing stocks too long. Despite the wide range of research evidence about this issue, the reasons that lead investors to act this way are still subject to much controversy between rational and behavioral explanations. In this article, the main goal was to test two competing behavioral motivations to justify the disposition effect: prospect theory and mean reversion bias. To achieve it, an analysis of monthly transactions for a sample of 51 Brazilian equity funds from 2002 to 2008 was conducted and regression models with qualitative dependent variables were estimated in order to set the probability of a manager to realize a capital gain or loss as a function of the stock return. The results brought evidence that prospect theory seems to guide the decision-making process of the managers, but the hypothesis that the disposition effect is due to mean reversion bias could not be confirmed.

Health financing changes in the context of health care decentralization: the case of three Latin American countries

OBJECTIVE: The results of an evaluative longitudinal study, which identified the effects of health care decentralization on health financing in Mexico, Nicaragua and Peru are presented in this article. METHODS: The methodology had two main phases. In the first, secondary sources of data and documents were analyzed with the following variables: type of decentralization implemented, source of financing, funds for financing, providers, final use of resources, mechanisms for resource allocation. In the second phase, primary data were collected by a survey of key personnel in the health sector. RESULTS: Results of the comparative analysis are presented, showing the changes implemented in the three countries, as well as the strengths and weaknesses of each country in matters of financing and decentralization. CONCLUSIONS: The main financing changes implemented and quantitative trends with respect to the five financing indicators are presented as a methodological tool to implement corrections and adjustments in health financing.

Effects of health decentralization, financing and governance in Mexico

OBJECTIVE: To identify the effects of decentralization on health financing and governance policies in Mexico from the perspective of users and providers. METHODS: A cross-sectional study was carried out in four states that were selected according to geopolitical and administrative criteria. Four indicators were assessed: changes and effects on governance, financing sources and funds, the final destination of resources, and fund allocation mechanisms. Data collection was performed using in-depth interviews with health system key personnel and community leaders, consensus techniques and document analyses. The interviews were transcribed and analyzed by thematic segmentation. RESULTS: The results show different effectiveness levels for the four states regarding changes in financing policies and community participation. Effects on health financing after decentralization were identified in each state, including: greater participation of municipal and state governments in health expenditure, increased financial participation of households, greater community participation in low-income states, duality and confusion in the new mechanisms for coordination among the three government levels, absence of an accountability system, lack of human resources and technical skills to implement, monitor and evaluate changes in financing. CONCLUSIONS: In general, positive and negative effects of decentralization on health financing and governance were identified. The effects mentioned by health service providers and users were related to a diversification of financing sources, a greater margin for decisions around the use and final destination of financial resources and normative development for the use of resources. At the community level, direct financial contributions were mentioned, as well as in-kind contributions, particularly in the form of community work.

Pathology of periportal fibrosis involution in human schistosomiasis

Optical and electron microscopical evidences of focal matrix degradation were frequently seen in liver sections of periportal fibrosis caused by schistosomiasis mansoni in man. The material came from 14 wedge hepatic biopsies taken from patients with chronic advanced hepatosplenic disease and undergoing operations for the relief of portal hypertension. Besides the presence of focal areas of rarefaction, fragmentation and dispersion of collagen fibers, the enlarged portal spaces also showed hyperplasia of elastic tissue and disarray of smooth muscle fibers following destruction of portal vein branches. Eggs were scanty in the tissue sections, and matrix degradation probably represented involuting changes related to the progressive diminution of parasite-related aggression, which occurs spontaneously with age or after cure by chemotherapy. The changes indicative of matrix degradation now described are probably the basic morphological counterpart of periportal fibrosis involution currently being documented by ultrasonography in hepatosplenic patients submitted to curative chemotherapy.

Kinetics of Trypanosoma cruzi destruction in the mouse spleen

Massive destruction of parasitized splenic macrophages was histologically observed at the height of a virulent infection caused by Trypanosoma cruzi (Y strain) in the mouse. This was coincident with a sudden drop in parasitemic curve. Most of the animals died at this point, probably due to the liberation of toxic products, such as TNF, following the massive destruction of parasitized cells. However, parasitized-cell destruction indicated the transition from susceptibility to resistance. Although it has been extensively studied in vitro, this study contributes with the morphological counterpart observed in vivo by optical and electron microscopy. When infected animals were specifically treated during early infection transition to chronic phase was immediately observed without splenic parasitism. Animals that apparently recovered from massive cell-destruction in the spleen showed evidences of a rapid restoration of splenic architecture.

Feasibility study of the immunogenicity and safety of a novel DTPw/Hib (PRP-T) Brazilian combination compared to a licensed vaccine in healthy children at 2, 4, and 6 months of age

Vaccination of infants with conjugated Haemophilus influenzae type b (Hib) vaccines has been proven to reduce Hib meningitis by 95% and pneumoniae by 20%. The routine use of Hib vaccine is facilitated by the introduction of combination vaccines into the EPI (Expanded Plan of Immunization). The objective of this study was to compare the immunogenicity and reactogenicity of an extemporaneously mixed DTPw/Hib (diphtheria-tetanus-whole cell pertussis) combination, using the technology of two Brazilian manufacturers, against a licensed DTPw/Hib European combination in 108 infants vaccinated at 2, 4 and 6 months according to the local national schedule. The Brazilian combination was highly immunogenic with Hib seroprotection rates (anti-PRP > 0.15 mg /ml of 98% after 2 doses and 100% after 3). Also for tetanus and pertussis the new Brazilian combination was as immunogenic as the European counterpart, except the diphtheria seroprotection rates and titers were lower. There was also no clinically relevant difference in reactogenicity. If these feasibility results are confirmed, the Brazilian DTPw/Hib combination should help to boost the uptake of Hib vaccination in Brazil.

Perceptions of the usefulness of external support to immunization coverage in Guinea-Bissau: a Delphi analysis of the GAVI-Alliance cash-based support

INTRODUCTION: Although many countries have improved vaccination coverage in recent years, some, including Guinea-Bissau, failed to meet expected targets. This paper tries to understand the main barriers to better vaccination coverage in the context of the GAVI-Alliance (The Global Alliance for Vaccines and Immunisation) cash-based support provided to Guinea-Bissau. METHODS: The analysis is based on a document analysis and a three round Delphi study with a final consensus meeting. RESULTS: Consensus attributed about 25% of the failure to perform better to implementation problems; and about 10% to governance and also 10% to scarce resources. The qualitative analysis validates the importance of implementation issues and upgraded the relevance of the human resources crisis as an important drawback. The recommendations were balanced in their upstream-downstream focus but were blind to health information issues and logistical difficulties. CONCLUSIONS: It is commendable that such a fragile state, with all sorts of barriers, manages to sustain a slow steady growth of its vaccination coverage. Not reaching the targets set reflects the inappropriateness of those targets rather than a lack of commitment of the health workforce. In the unstable context of countries such as Guinea-Bissau, the predictability of the funds from global health initiatives like the GAVI-Alliance seem to make all the difference in achieving small consistent health gains even in the presence of other major bottlenecks.

Changes in the amount of soluble carbohydrates and polyphenols contents during decomposition of Montrichardia arborescens (L.) Schott

This study describes the aerobic and anaerobic decay of soluble carbohydrates (CH) and polyphenols (PH) during decomposition of Montrichardia arborescens. Plant and water samples were collected in the Cantá stream (2º 49' 11" N and 60º 40' 24" W), Roraima, Brazil. Decomposition chambers with plant fragments and stream water were incubated. Particulate organic matter was separated from dissolved organic matter and concentrations of CH and PH were determined. The results were fitted to 1st order kinetics models. CH and PH comprised a labile fraction (LCH and LPH) and a refractory fraction (RCH and RPH). The global coefficient associated with LCH weight loss was 1.4 times higher under aerobic conditions (3.4 day-1) higher than for anaerobic conditions. On the other hand, the RCH decay rate in the anaerobic process (0.0074 day-1) was 1.39 times higher. LCH was estimated to be 92% while RCH amounted to 8%. The LPH anaerobic decay was 5.2 times the value for the aerobic decay (0.67 day-1). For both conditions, RPH decay coefficients were similar (» 0.011 day-1). In the aerobic experiments LPH and RPH corresponded to 92.5% and 7.5%, respectively. For the anaerobic process these contents were 85.5% and 14.5%, respectively. From these results, we concluded that in the Cantá stream, the anaerobic degradation of phenols is more efficient than the aerobic counterpart. The aerobic condition provides a faster decay of carbohydrates of this plant.

Recent brazilian experience on farmer reaction and crop response to fertilizer use

(1) In the period 1965/77 fertilizer consumption in Brazil increased nearly fifteen foild from circa 200,000 tons of N + P2O5 + K2O to 3 million tons. During the fifteen years extending from 1950 to 1964 usage of the primary macronutrients was raised by a factor of 2 only. (2) Several explanations are given for the remarkable increase, namely: an experimental background which supplied data for recommendations of rates, time and type of application; a convenient governmental policy for minimum prices and rural credit; capacity of the industry to meet the demand of the fertilizer market; an adequate mechanism for the diffusion of the practice of fertilizer use to the farmer. (3) The extension work, which has caused a permanent change in the aptitude towards fertilization, was carried out in the traditional way by salesmen supported by a technical staff, as well as by agronomists of the official services. (4) Two new programs were started and conducted in a rather short time, both putting emphasis on the relatively new technology of fertilizer use. (5) The first program, conducted in the Southern part of the country, extended lab and green house work supplemented by a few field trials to small land owners - the so called "operação tatú" (operation armadillo). (6) The seconde program, covering a larger problem area in the Northeast and in Central Brazil, began directly in field as thousands of demonstrations and simple experiments with the participation of local people whose involvement was essential for the success of the initiative; in this case the official extension services, both foreign and national sources of funds, and universities did participate under the leadership of the Brazilian Association for the Diffusion of Fertilizers (ANDA). (7) It is felt that the Brazilian experience gained thereof could be useful to other countries under similar conditions.

Tetraploidía en Ceratophrys (Anura, Leptodactylidae), análisis del registro fósil

It has been confirmed the existence of the tetraploid counterpart of the genus Ceratophrys Wied, 1824 (extint at the present time) in Argentina and Brazil since the Pliocene, and the apparition of the octaploidy in the Upper Pleistocene - Holocene. Fossil material of the diploid form, distinctive of the Chacoan District, has been reported from the horizons of the Montehermosense Formation in south-east of the province of Buenos Aires, Argentina. The coexistence of diploid-tetraploid and tetraploid-octaploid forms in the same province was documented.

Harmonization of research and control in schistosomiasis

I have been employed by several different organizations during over 30 years working on schistosomiasis, the majority spent in endemic areas of Caribean, South America, Africa and the Western Pacific. Much of the work is best classified as applied research but sometimes it strayed to the extremes of either public health control programmes or pure research. Over this period, there have been several significant research developments that have altered our whole approach to control. Ideally, research and control should complement each other but, in reality, they sometimes have conflicting objectives. Public health workers understandably wish to provide immediate, shot-term protection to the communities in their care, but research workers may, within ethical limits, reasonably want to observe untreated communities for extended periods in order to understand the underluing process of transmission, disease pathogenesis and immunity to help develop more effective control measures. An example of this situation has occured recently in Senegal where water development projects seem to have favoured the introduction and spreed of Schistosoma mansoni in the Senegal River Basin. I have been asked to be the scientific consultant to the newly formed ESPOIR programme, linking European research organizations and the Senegal Ministry of Health, to reconcile the conflictiong aims of public health workers, wishing to use whatever funds can be obtained for an immediate chemotherapy to try to eliminate the focus, at present confined to the vicinity of a relatively small, commercially run sugar irrigation scheme; and research workers who see a rare chance to study the development of immune mechanisms in a adults in a community not previously exposed to the infection. This information could prove invaluable in understanding the development of immunity and the pathogenesis of disease, leading eventually to the development of vaccines to revolutionise the future approach to schistosomiasis...

Morphological features of collagen degradation in advanced hepatic schistosomiasis of man

Optical and electron microscopical evidences of focal matrix degradation were frequently seen in liver sections taken from patients with periportal ("pipe-stem") fibrosis caused by schistosomiasis mansoni. Besides present of focal areas of rarefaction, fragmentation and dispersion of collagen fibers, the enlargend portal spaces also showed hyperplasia of elastic tisue and disarray of smooth muscle fibers following the destrution of portal vein branches. Ultrastructural cahnges represented by focal lytic and/or electron dense alterations of colagen fibrils were similar to those first seen in experimental material and designated as "chronic collagen degradation". Elastin and related microfibrils were also affected by focal condensation, fragmentation, distorsion and dissolution. Schistosome eggs were scanty in the tissue sections examined. Matrix degradation represented involuting changes related to the progressive diminution of parasite aggression, which occurs spontaneously with age or after cure by chemotherapy. Changes of focal matrix degradation now being described represent the basic morphological counterpart of periportal fibrosis involution documented clinically, especially by ultrasonography, in patients with hepatosplenic schistosomiasis submitted to curative chemotherapy.

Schistosomiasis control in China

After three decades' efforts, schistosomiasis japonica were controlled in one-third (4/12) of endemic provinces and 68.2 (259/380) of endemic counties throughout the country. The remaining 121 endemic counties are located primarily in the lake and mountainous regions. The epidemiological and ecological features of the lake and mountainous areas are different from the other endemic areas. The major schistosomiasis control efforts in China can be characterized as follows: (1) Application of centralized leadership and management, since schistosomiasis control is a task not only of the Ministry of Public Health, but also of all local governments in the endemic areas; (2) Integration of actions taken by various departments or bureaus, such as agriculture, water conservation and public health; (3) Promotion of mass participation; (4) Organization of strong professional teams; (5) Raising sufficient funds. Strategies on schistosomiasis control applied in different areas are divided into three levels: (1) In the areas where the schistosomiasis has been successfully controlled, surveillance must be maintained and immediate action should be taken where new infections occur and/or vector snails are found, so that control can be reestablished quickly; (2) In the areas where schistosomiasis has been partially controlled, any residents and/or live-stock infected should be examined and treated promptly with due care, and environment modifying and/or mollusciding must be used to eliminate the remaining snails; (3) In the areas where transmission has not been controlled, the main strategy is to control morbidity. Mass or selective chemotherapy with praziquental should be applied to both infected persosns and the live-stock, and environment modification for the snail-ridden areas should be taken but should be coordinated with agriculture where possible. Advance cases must be treated; and epidemics of Katayama fever prevented; water supply and sanitation shoud be improved and health education emphasized. Annual mass or selective chemotherapy with praziquental both reduces the prevalence rate and decreases the intensity of the infection for inhabitants and live-stock. As a consequence of the therapy a low prevalence rate can be obtained in a short time. The length of such arrangement period can be decided in accordance with the prevalence of the infection before the drug program is begun. Therefore,a maintenance phase is urgently needed. As China's ecomony expands and people's living standard rises, schistosomiasis will be controlled more effectively and successfully.

Expression of Recombinant Antigens in Escherichia coli: Application on Immunochemical Studies of Schistosoma mansoni Tegumental Antigens

Sm15 and Sm13 are recognized by antibodies from mice protectively vaccinated with tegumental membranes, suggesting a potential role in protective immunity. In order to raise antibodies for immunochemical investigations, the genes for these antigens were expressed in pGEX and pMal vectors so that comparisons could be made among different expression systems and different genes. The fusion proteins corresponding to several parts of the gene for the precursor of Sm15 failed in producing antibodies recognizing the parasite counterpart. On the other hand, antibodies raised against Sm13 MBP-fusion proteins recognized the 13 kDa tegumental protein. Thus the peculiarities of the gene of interest are important and the choice of the expression system must sometimes be decided on an empirical basis

Molecular Modeling Approaches for Determining Gene Function: application to a Putative Poly-A Binding Protein from Leishmania amazonensis (LaPABP)

The great expansion in the number of genome sequencing projects has revealed the importance of computational methods to speed up the characterization of unknown genes. These studies have been improved by the use of three dimensional information from the predicted proteins generated by molecular modeling techniques. In this work, we disclose the structure-function relationship of a gene product from Leishmania amazonensis by applying molecular modeling and bioinformatics techniques. The analyzed sequence encodes a 159 aminoacids polypeptide (estimated 18 kDa) and was denoted LaPABP for its high homology with poly-A binding proteins from trypanosomatids. The domain structure, clustering analysis and a three dimensional model of LaPABP, basically obtained by homology modeling on the structure of the human poly-A binding protein, are described. Based on the analysis of the electrostatic potential mapped on the model's surface and conservation of intramolecular contacts responsible for folding stabilization we hypothesize that this protein may have less avidity to RNA than it's L. major counterpart but still account for a significant functional activity in the parasite. The model obtained will help in the design of mutagenesis experiments aimed to elucidate the mechanism of gene expression in trypanosomatids and serve as a starting point for its exploration as a potential source of targets for a rational chemotherapy.