João Eduardo Ferreira

Trends in antiretroviral drug resistance and clade distributions among HIV-1--infected blood donors in Sao Paulo, Brazil.

Background: We analyzed rates of drug resistance mutations in antiretroviral-naive São Paulo blood donors with recently acquired or established HIV-1 infections and characterized clade diversity in this population. Methods: Six hundred forty-eight seropositive blood donor specimens were identified at the Blood Center of São Paulo between July 1998 and March 2002. To discriminate recent infections, samples were subjected to the standardized testing algorithm for recent HIV seroconversion (less-sensitive enzyme immunoassay) testing algorithm. There were 531 samples with a sufficient volume of serum to attempt polymerase chain reaction (PCR) and viral sequencing; 341 (64%) samples yielded a PCR product that could be sequenced for the reverse transcriptase and protease genes. Mutations were analyzed using the 2005 International AIDS Society mutation list. Results: Of 341 specimens successfully analyzed, 21 (6.3%; 95% confidence interval [CI]: 3.9% to 9.3%) had drug-resistant mutations. The proportion of resistant strains was 12.7% (95% CI: 5.2% to 24.5%) among recently infected individuals compared with 5.0% (95% CI: 2.8% to 8.2%) among those with long-standing infections (P = 0.03). No change in the proportion of drug-resistant strains was observed among recently infected donor samples from the first half of the study period (4 of 32 samples) as compared with the second half (3 of 23 samples; P = 0.95). Of the 341 samples, 277 (81.2%) were classified as subtype B, 25 (7.3%) as subtype F1, 13 (3.8%) as subtype C, and 26 (7.6%) as recombinant strains. The distribution of HIV-1 subtypes was similar among recent and long-standing infected individuals and over time. Conclusions: The prevalence of drug-resistant mutations among newly diagnosed persons in São Paulo city is low and similar to what has been described in Europe and the United States. Although HIV-1 subtype B remains predominant, subtypes F and C and recombinant forms are present in substantial proportions in infected donors.

Demographic profile of blood donors at three major Brazilian blood centers: results from the International REDS‐II study, 2007 to 2008

BACKGROUND: The profile of blood donors changed dramatically in Brazil over the past 20 years, from remunerated to nonremunerated and then from replacement to community donors. Donor demographic data from three major blood centers establish current donation profiles in Brazil, serving as baseline for future analyses and tracking longitudinal changes in donor characteristics.

Human immunodeficiency virus prevalence, incidence, and residual risk of transmission by transfusions at Retrovirus Epidemiology Donor Study-II blood centers in Brazil

BACKGROUND: In Brazil nationally representative donor data are limited on human immunodeficiency virus (HIV) prevalence, incidence, and residual transfusion risk. The objective of this study was to analyze HIV data obtained over 24 months by the Retrovirus Epidemiology Donor Study‐II program in Brazil.

Prevalence of serologic markers for hepatitis B and C viruses in Brazilian blood donors and incidence and residual risk of transfusion transmission of hepatitis C virus.

BACKGROUND: We evaluate the current prevalence of serologic markers for hepatitis B virus (HBV) and hepatitis C virus (HCV) in blood donors and estimated HCV incidence and residual transfusion‐transmitted risk at three large Brazilian blood centers.

A partial persistent data structure to support consistency in real-time collaborative editing

Co-authored documents are becoming increasingly important for knowledge representation and sharing. Tools for supporting document co-authoring are expected to satisfy two requirements: 1) querying changes over editing histories; 2) maintaining data consistency among users. Current tools support either limited queries or are not suitable for loosely controlled collaborative editing scenarios. We address both problems by proposing a new persistent data structure-partial persistent sequence. The new data structure enables us to create unique character identifiers that can be used for associating meta-information and tracking their changes, and also design simple view synchronization algorithms to guarantee data consistency under the presence of concurrent updates. Experiments based on real-world collaborative editing traces show that our data structure uses disk space economically and provides efficient performance for document update and retrieval.

Integration of business processes with autonomous information systems: a case study in government services

This research addresses the problem of business process integration in autonomous information systems. The unified control unit defines the navigation plan for each electronic service requisition belonging to the autonomous information systems. Each electronic service requisition navigates through various levels of consistency rules until it is stored into the specific autonomous database systems. In this paper, we use Riverfishs architecture to unify the business processes in autonomous information systems. This research is illustrated through a case study in government services.

An environment for knowledge discovery in biology

This paper describes a data mining environment for knowledge discovery in bioinformatics applications. The system has a generic kernel that implements the mining functions to be applied to input primary databases, with a warehouse architecture, of biomedical information. Both supervised and unsupervised classification can be implemented within the kernel and applied to data extracted from the primary database, with the results being suitably stored in a complex object database for knowledge discovery. The kernel also includes a specific high-performance library that allows designing and applying the mining functions in parallel machines. The experimental results obtained by the application of the kernel functions are reported.

Analysis of donor deferral at three blood centers in Brazil.

BACKGROUND: The safety of the blood supply is ensured through several procedures from donor selection to testing of donated units. Examination of the donor deferrals at different centers provides insights into the role that deferrals play in transfusion safety.

Using control-flow patterns for specifying business processes in cooperative environments

The representation and execution of business processes have generated some important challenges in Computer Science. An important related concern is the choosing of the best formal foundation to specify processes behavior, mainly representing control-flow patterns in cooperative environments. The first contribution of this research is the complete definition of the Navigation Plan Definition Language (NPDL) as an alternative for business process managing in cooperative environments. The second contribution is a complete implementation of control-flow patterns using NPDL. These control-flow patterns have been proposed by Aalsts group. Our experience in applying suggestion of Aalsts group to use control-flow patterns as a basis for comparison among control-flow specification languages shows that this comparison method is feasible and the results are useful. The simplicity of NPDL representations shows the advantages of NPDL as a process specification language. NPDL uses a declarative specification (similar to process algebra) to describe the workflow and adds new operators to compensate for the limitations of process algebra and Petri nets. NPDL also increases the modeling flexibility by allowing the reuse of process expressions in relational data-base systems.

Integration of collaborative information system in Internet applications using RiverFish architecture

Business process integration is a serious challenge in collaborative information systems due to the potential interference among them. This paper describes RiverFish architecture to solving integration problems in collaborative information systems that belong to e-commerce environment. DECA application has been used to show a good example of a non-trivial problem of this integration. DECA application controls the processing application involving several government agencies to illustrate a new application called DECA. Each step of DECA processes various levels of check points and stores the results into associated collaborative information systems. This application has served more than 2 million users since 2000, demonstrating the reliability and support for evolution of RiverFish approach