Simulação de técnicas de engenharia de reservatórios: exemplo de utilização de opções reais

Este trabalho teve como objetivo incluir flexibilidade gerencial (tais como técnicas de recuperação complementar de óleo) na avaliação de reservatórios. Concluímos que essas técnicas podem aumentar o valor dos reservatórios em até 25% segundo a teoria de opções reais. A principal vantagem da metodologia de teoria de opções em relação à tradicional técnica de fluxo de caixa descontado é levar em conta as questões operacionais da indústria do petróleo. Utilizamos dois modelos clássicos para a precificação de reservatórios de petróleo e aplicamos uma análise de sensibilidade para determinar quais fatores são mais relevantes no seu valor econômico. Como era de se esperar, em ambos os modelos, o tempo de concessão e a taxa de convenience e/ou dividend yield foram os fatores mais importantes.

Ambivalent implications of health care information systems: a study in the Brazilian public health care system

This article evaluates social implications of the "SIGA" Health Care Information System (HIS) in a public health care organization in the city of São Paulo. The evaluation was performed by means of an in-depth case study with patients and staff of a public health care organization, using qualitative and quantitative data. On the one hand, the system had consequences perceived as positive such as improved convenience and democratization of specialized treatment for patients and improvements in work organization. On the other hand, negative outcomes were reported, like difficulties faced by employees due to little familiarity with IT and an increase in the time needed to schedule appointments. Results show the ambiguity of the implications of HIS in developing countries, emphasizing the need for a more nuanced view of the evaluation of failures and successes and the importance of social contextual factors.

Epidemiological methods for research with drug misusers: review of methods for studying prevalence and morbidity

Epidemiological studies of drug misusers have until recently relied on two main forms of sampling: probability and convenience. The former has been used when the aim was simply to estimate the prevalence of the condition and the latter when in depth studies of the characteristics, profiles and behaviour of drug users were required, but each method has its limitations. Probability samples become impracticable when the prevalence of the condition is very low, less than 0.5% for example, or when the condition being studied is a clandestine activity such as illicit drug use. When stratified random samples are used, it may be difficult to obtain a truly representative sample, depending on the quality of the information used to develop the stratification strategy. The main limitation of studies using convenience samples is that the results cannot be generalised to the whole population of drug users due to selection bias and a lack of information concerning the sampling frame. New methods have been developed which aim to overcome some of these difficulties, for example, social network analysis, snowball sampling, capture-recapture techniques, privileged access interviewer method and contact tracing. All these methods have been applied to the study of drug misuse. The various methods are described and examples of their use given, drawn from both the Brazilian and international drug misuse literature.

Core group approach to identify college students at risk for sexually transmitted infections

OBJECTIVE: To analyze the core group for sexually transmitted infections (STI) among college students. METHODS: Cross-sectional study carried out in a convenience sample comprising 711 college students of the public university of Morelos, Mexico, between 2001 and 2003. Sociodemographic and sexual behavior information were collected using self-applied questionnaires. Herpes simplex 2 (HSV-2) infection was tested in the blood. The number of sexual partners in the last year and cocaine consumption were used as indicators to construct the dependent variable "level of STI risk" in three categories: low, medium and high risk (core group). A multinomial analysis was conducted to evaluate whether different sex behaviors were associated with the variable "level of STI risk". RESULTS: There was significant association between HSV-2 seroprevalence and the variable "level of STI risk": 13%, 5.6% and 3.8% were found in high (core group), medium and low categories, respectively. There were gender differences regarding the core group. Men started having sexual intercourse earlier, had more sex partners, higher alcohol and drug consumption, higher frequency of sex intercourse with sex workers, exchanging sex for money, occasional and concurrent partners compared to women. CONCLUSIONS: The study findings suggest existing contextual characteristics in the study population that affect their sex behavior. In Mexico, the cultural conception of sexuality is determined mainly by gender differences where men engage in higher risky sexual behavior than women.

Young people's blood alcohol concentration and the alcohol consumption city law, Brazil

The paper assesses blood alcohol concentration and risk behaviors for traffic accidents before and after the implementation of a law which prohibits the use of alcoholic beverages on city gas stations. In Porto Alegre, Southern Brazil, young people go out at night and drive to gas station convenience stores to buy alcoholic beverages which are consumed on the premises of parking lots in gas stations. Data were obtained from self-administered questionnaires and breath analyzers in two cross-sectional collections with purposive samples of youngsters in May and July 2006 (n=62, and n=50, respectively). There were no significant differences between the groups before and after the city law was passed. Blood alcohol concentration greater than 0.06% was found in 35.5% of pre-law group and 40% of post-law group (p=0.62). Results point out heavy alcohol use in both groups, which did not change after the law was passed.

HIV rapid testing as a key strategy for prevention of mother-to-child transmission in Brazil

OBJECTIVE: To assess the feasibility of HIV rapid testing for pregnant women at maternity hospital admission and of subsequent interventions to reduce perinatal HIV transmission. METHODS: Study based on a convenience sample of women unaware of their HIV serostatus when they were admitted to delivery in public maternity hospitals in Rio de Janeiro and Porto Alegre, Brazil, between March 2000 and April 2002. Women were counseled and tested using the Determine HIV1/2 Rapid Test. HIV infection was confirmed using the Brazilian algorithm for HIV infection diagnosis. In utero transmission of HIV was determined using HIV-DNA-PCR. There were performed descriptive analyses of sociodemographic data, number of previous pregnancies and abortions, number of prenatal care visits, timing of HIV testing, HIV rapid test result, neonatal and mother-to-child transmission interventions, by city studied. RESULTS: HIV prevalence in women was 6.5% (N=1,439) in Porto Alegre and 1.3% (N=3.778) in Rio de Janeiro. In Porto Alegre most of women were tested during labor (88.7%), while in Rio de Janeiro most were tested in the postpartum (67.5%). One hundred and forty-four infants were born to 143 HIV-infected women. All newborns but one in each city received at least prophylaxis with oral zidovudine. It was possible to completely avoid newborn exposure to breast milk in 96.8% and 51.1% of the cases in Porto Alegre and Rio de Janeiro, respectively. Injectable intravenous zidovudine was administered during labor to 68.8% and 27.7% newborns in Porto Alegre and Rio de Janeiro, respectively. Among those from whom blood samples were collected within 48 hours of birth, in utero transmission of HIV was confirmed in 4 cases in Rio de Janeiro (4/47) and 6 cases in Porto Alegre (6/79). CONCLUSIONS: The strategy proved feasible in maternity hospitals in Rio de Janeiro and Porto Alegre. Efforts must be taken to maximize HIV testing during labor. There is a need of strong social support to provide this population access to health care services after hospital discharge.

Short Assessment of Health Literacy for Portuguese-speaking Adults

OBJECTIVE: To develop and validate a short health literacy assessment tool for Portuguese-speaking adults. METHODS: The Short Assessment of Health Literacy for Portuguese-speaking Adults is an assessment tool which consists of 50 items that assess an individual's ability to correctly pronounce and understand common medical terms. We evaluated the instrument's psychometric properties in a convenience sample of 226 Brazilian older adults. Construct validity was assessed by correlating the tool scores with years of schooling, self-reported literacy, and global cognitive functioning. Discrimination validity was assessed by testing the tool's accuracy in detecting inadequate health literacy, defined as failure to fully understand standard medical prescriptions. RESULTS: Moderate to high correlations were found in the assessment of construct validity (Spearman's coefficients ranging from 0.63 to 0.76). The instrument showed adequate internal consistency (Cronbach's alpha=0.93) and adequate test-retest reliability (intraclass correlation coefficient=0.95). The area under the receiver operating characteristic curve for detection of inadequate health literacy was 0.82. A version consisting of 18 items was tested and showed similar psychometric properties. CONCLUSIONS: The instrument developed showed good validity and reliability in a sample of Brazilian older adults. It can be used in research and clinical settings for screening inadequate health literacy.

Factors associated with arterial stiffness in children aged 9-10 years

OBJECTIVE To analyze the factors associated with stiffness of the great arteries in prepubertal children.METHODS This study with convenience sample of 231 schoolchildren aged 9-10 years enrolled in public and private schools in Vitória, ES, Southeastern Brazil, in 2010-2011. Anthropometric and hemodynamic data, blood pressure, and pulse wave velocity in the carotid-femoral segment were obtained. Data on current and previous health conditions were obtained by questionnaire and notes on the child’s health card. Multiple linear regression was applied to identify the partial and total contribution of the factors in determining the pulse wave velocity values.RESULTS Among the students, 50.2% were female and 55.4% were 10 years old. Among those classified in the last tertile of pulse wave velocity, 60.0% were overweight, with higher mean blood pressure, waist circumference, and waist-to-height ratio. Birth weight was not associated with pulse wave velocity. After multiple linear regression analysis, body mass index (BMI) and diastolic blood pressure remained in the model.CONCLUSIONS BMI was the most important factor in determining arterial stiffness in children aged 9-10 years.

Factors associated with dietary supplement use by people who exercise at gyms

OBJECTIVE To assess the factors associated with the use of dietary supplements by people who exercise at gyms.METHODS A cross-sectional study with a sample defined by convenience, considering the number of gyms registered in the Conselho Regional de Educação Física (Regional Council of Physical Education) of Sao Luis, MA, Northeastern Brazil, from July 2011 to July 2012. The final sample comprised 723 individuals who exercise at gyms. The dependent variable was supplement use, and the explanatory variables were length of time and motivation of the physical exercises, duration, goal and self-perception of training, weekly frequency of gym attendance, sex, age, educational attainment, self-perception of body weight, smoking and self-perception of diet. The association between variables was analysed by hierarchical Poisson regression based on a theoretical model.RESULTS Supplement use was reported by 64.7% of the participants. Most of the sample was male (52.6%). The most frequent age group was 20 to 39 years (74.4%). Most participants (46.1%) had been exercising for over a year. The following variables were associated with supplement use: self-perceiving body weight as below ideal (p < 0.001), smoking (p < 0.001), exercising for 7 to 12 months (p = 0.028) or more than one year (p < 0.001), spending more than two hours at the gym (p = 0.051), and perceiving training as moderate (p = 0.024) or intense (p = 0.001).CONCLUSIONS The use of supplements lacks proper professional guidance, being motivated by individuals unsatisfied with their low body weight and who perceive their workout as intense, which raises the need for monitoring this population.

Work, malaise, and well-being in Spanish and Latin-American doctors

ABSTRACT OBJECTIVE To analyze the relations between the meanings of working and the levels of doctors work well-being in the context of their working conditions. METHOD The research combined the qualitative methodology of textual analysis and the quantitative one of correspondence factor analysis. A convenience, intentional, and stratified sample composed of 305 Spanish and Latin American doctors completed an extensive questionnaire on the topics of the research. RESULTS The general meaning of working for the group located in the quartile of malaise included perceptions of discomfort, frustration, and exhaustion. However, those showing higher levels of well-being, located on the opposite quartile, associated their working experience with good conditions and the development of their professional and personal competences. CONCLUSIONS The study provides empirical evidence of the relationship between contextual factors and the meanings of working for participants with higher levels of malaise, and of the importance granted both to intrinsic and extrinsic factors by those who scored highest on well-being.

Study on the growth promoting capacity of calf and fetal bovine serum for animal cells "in vitro" II: electrophoretic study and survey on the antiproteolytic activity of pools of calf and fetal bovine serum

Calf serum and fetal bovine serum present great variability as to its growth promoting efficiency (GPE). As supplement of culture media to cultivate cells of animal origin they stimulate the "in vitro" multiplication and maintain cell viability. When fourteen lots of calf sera of variable GPE had the total protein contents as well as the percentages of serum fractions determined, no significant differences that could possibly explain the variability of the GPE were observed. Evaluation of the antiproteolytic activity of nineteen lots of calf serum and eighteen serum lots of younger calves showed that the former exhibited lower antiproteolytic titers (1:40 to 1:80) than the latter (1:80 to 1:160). Twelve lots of fetal bovine serum studied in parallel, showed the highest concentration of antiproteolytic factors, with titers equal to 1:320. Sera of bovine origin, but not fetal sera, are usually heat-inactivated, what was demonstrated to be responsible for the decrease of the antiproteolytic activity of 75% of the lots tested. This could explain the inability of certain heat-inactivated sera in promoting multiplication of some cells "in vitro", as verified with primary monkey kidney cells. The results obtained in this study indicated the convenience of submiting each lot of serum to be introduced in cell culture to previous determination of its characteristics, such as growth promoting efficiency, antiproteolytic activity and also toxicity, absence of extraneous agents, etc., in order to minimize the possibility of using serum lots of questionable quality, thus preventing not only the loss of cell lines, but also undesirable and sometimes expensive delays.

Passive haemagglutination test for human neurocysticercosis immunodiagnosis: II - Comparison of two standardized procedures for the passive haemagglutination reagent in the detection of anti-Cysticercus cellulosae antibodies in cerebrospinal fluids

A comparison of two different standardized reagent procedures for the passive haemagglutination test (PHA) in the detection of specific antibody to Cysticercus cellulosae in cerebrospinal fluid (CSF) was carried out. The formaldehyde-treated group O Rh-human red blood cells (HuRBC) and glutaraldehyde-treated sheep red blood cells (SRBC) were the supplies for the reagents preparation and, in the tests, they were designated as PHA-1 and PHA-2, respectively. For both reagents the cells were coated with the cysticerci total saline extract (TS) antigen. PHA-1 and PHA-2 were assessed in a total of 204 CSF from patients with neurocysticercosis, from non-related infections and from healthy individuals. The positivity and specificity indices obtained were respectively 81.7% and 94.4% for PHA-1 and for PHA-2, 88.7% and 96.6%. Since no significant differences were observed between the results provided by two reagents, at level of significance of 0.05, either processes of cell sensitization can alternatively be used according to the own laboratory convenience.

Prevalence and risk factors for Toxoplasma gondii infection among pregnant and postpartum women attended at public healthcare facilities in the City of Niterói, State of Rio de Janeiro, Brazil

IntroductionTo determine the prevalence of immunoglobulin G (IgG) and immunoglobulin M (IgM) anti-Toxoplasma gondii antibodies among pregnant and postpartum women attended within the public healthcare system in Niterói, State of Rio de Janeiro, and to detect possible exposure factors associated with T. gondii infection in this population.MethodsIgM and IgG anti-T. gondii antibodies were investigated in 276 pregnant and 124 postpartum women by using the indirect immunofluorescence (IFAT) and immunoenzymatic assay (ELISA) techniques. The participants were selected by convenience sampling. All these 400 patients filled out a free and informed consent statement, answered an epidemiological questionnaire and were informed about the disease.ResultsAmong the 400 samples analyzed, 234 (58.5%) were reactive to IgG anti-T. gondii antibodies, according to the IFAT and/or ELISA assay. One pregnant woman was found to be reactive to IgM anti-T. gondii antibodies, with an intermediate IgG avidity test. Risk factor analysis showed that seropositivity was significantly associated (p<0.05) with age, contact with cats and presence of rodents at home. Through a logistic regression model, these associations were confirmed for age and contact with cats, while education at least of the high school level was found to be a protective factor.ConclusionsThe prevalence rate of IgG anti-T. gondii antibodies in the City of Niterói was high and the risk factors for infection detected after multivariate analysis were: age over 30 years, contact with cats and education levels lower than university graduate level.

Cost of drugs manufactured by the University Hospital - role of the Central Pharmacy

The hospital pharmacy in large and advanced institutions has evolved from a simple storage and distribution unit into a highly specialized manipulation and dispensation center, responsible for the handling of hundreds of clinical requests, many of them unique and not obtainable from commercial companies. It was therefore quite natural that in many environments, a manufacturing service was gradually established, to cater to both conventional and extraordinary demands of the medical staff. That was the case of Hospital das Clinicas, where multiple categories of drugs are routinely produced inside the pharmacy. However, cost-containment imperatives dictate that such activities be reassessed in the light of their efficiency and essentiality. METHODS: In a prospective study, the output of the Manufacturing Service of the Central Pharmacy during a 12-month period was documented and classified into three types. Group I comprised drugs similar to commercially distributed products, Group II included exclusive formulations for routine consumption, and Group III dealt with special demands related to clinical investigations. RESULTS: Findings for the three categories indicated that these groups represented 34.4%, 45.3%, and 20.3% of total manufacture orders, respectively. Costs of production were assessed and compared with market prices for Group 1 preparations, indicating savings of 63.5%. When applied to the other groups, for which direct equivalent in market value did not exist, these results would suggest total yearly savings of over 5 100 000 US dollars. Even considering that these calculations leave out many components of cost, notably those concerning marketing and distribution, it might still be concluded that at least part of the savings achieved were real. CONCLUSIONS: The observed savings, allied with the convenience and reliability with which the Central Pharmacy performed its obligations, support the contention that internal manufacture of pharmaceutical formulations was a cost-effective alternative in the described setting.

Postpartum depression in Recife - Brazil: prevalence and association with bio-socio-demographic factors

OBJECTIVE:To use a semi-structured interview to detect depression in postpartum women according to the criteria proposed by the DSM in child health care clinics in the city of Recife, together with the proper association of this disorder to bio-socio-demographic data. METHODS: The study used a cross-section method and contained a convenience sample of 400 women that were between 2 and 26 weeks of postpartum in child health care clinics. A bio-socio-demographic questionnaire and the Portuguese version of the Structured Clinical Interview for DSM-IV Axis I Disorders were used. RESULTS: Twenty nine of the mothers (7.2%) were diagnosed as suffering from postpartum depression. Women with a past history of psychiatric disorders, a family history of psychiatric disorder and some sort of clinical complication presented a higher prevalence of depression. The same happened to those with a past history of spontaneous abortion, those who had a transpelvic birth and those over 8 weeks of puerperium. CONCLUSION: The rate of postpartum depression in this sample, 7.2%, was lower than that reported by other Brazilian studies. It probably occurred because the other researchers used screening scales to assess this estimate instead of a clinical interview.