Hybrid Self-Adaptive Evolution Strategies Guided by Neighborhood Structures for Combinatorial Optimization Problems.

This article presents an Evolution Strategy (ES)--based algorithm, designed to self-adapt its mutation operators, guiding the search into the solution space using a Self-Adaptive Reduced Variable Neighborhood Search procedure. In view of the specific local search operators for each individual, the proposed population-based approach also fits into the context of the Memetic Algorithms. The proposed variant uses the Greedy Randomized Adaptive Search Procedure with different greedy parameters for generating its initial population, providing an interesting exploration-exploitation balance. To validate the proposal, this framework is applied to solve three different [Formula: see text]-Hard combinatorial optimization problems: an Open-Pit-Mining Operational Planning Problem with dynamic allocation of trucks, an Unrelated Parallel Machine Scheduling Problem with Setup Times, and the calibration of a hybrid fuzzy model for Short-Term Load Forecasting. Computational results point out the convergence of the proposed model and highlight its ability in combining the application of move operations from distinct neighborhood structures along the optimization. The results gathered and reported in this article represent a collective evidence of the performance of the method in challenging combinatorial optimization problems from different application domains. The proposed evolution strategy demonstrates an ability of adapting the strength of the mutation disturbance during the generations of its evolution process. The effectiveness of the proposal motivates the application of this novel evolutionary framework for solving other combinatorial optimization problems.

Analysis of survival after primary liver transplantation: multivariate analysis of 155 cases in a single center.

Liver transplantation is known as a highly complex procedure. Several variables can affect the outcome. The present study is a retrospective multivariate analysis of the outcomes of primary liver transplant recipients from deceased donors. From November 2006 through January 2009, 155 patients received first liver transplants from deceased donors. The data included the following: age of the recipient, gender of the recipient, ABO type, indication for the transplantation, model for end-stage liver disease (MELD) score, operative time, donor age, gender of the donor, cold ischemia time, and quantity of transfused blood products-red blood cells (PRBC), red blood cells recovered during the operation (cell saver), platelets, and fresh frozen plasma. Statistical analysis was done using SPSS 17 software. Cox regression analysis was performed to identify significant variables. ROC (receiver operating characteristic) curve was applied for those significant factors. Among all variables, only PRBC transfusion and MELD score showed statistical significance. For PRBC the increment of death risk was 17.08%, and for MELD score it was 3.83%. Patients that had to use PRBC and higher MELD scores had worse survivals. We concluded that the requirement for red blood cell transfusions and MELD showed the most significant influences on the outcomes of adult liver transplantations from deceased donors.

Prevalence of posttransplantation lymphoproliferative disease in pediatric liver transplant recipients.

OBJECTIVE: The objective of this study was to identify the incidence of posttransplantation lymphoproliferative disease (PTLD) among children within 1 year after liver transplantation. METHODS: This retrospective review analyzed information in medical charts of pediatric (younger than 18 years of age) recipients of liver transplants between September 2000 and December 2007. RESULTS: Seventy-one patients underwent a liver transplantation and 7 (9.85%) developed PTLD. Among this group, 6 children were girls and 1 was a boy. The median age at transplantation was 35.14 months. Indications that led the children to have their transplantation were 1 case of hemangioendothelioma, 1 case of autoimmune hepatic cirrhosis, 1 case of alpha-1-antitrypsin deficiency, and 4 cases of biliary atresia. The most frequent symptoms were splenomegaly, diarrhea, and fever. The median time from the first symptoms to the initial treatment was 9.7 days. The standard treatment was withdrawal of immunosuppression and close observation of tacrolimus levels and liver function tests associated with antiviral drugs and chemotherapy. Four among 7 children died; 3 children recovered. All 3 children who recovered has presented at the transplantation center within 5 days of initiation of symptoms (P = .033896). CONCLUSION: Despite its rarity, when it occurs, PTLD shows a high mortality rate. Therefore, it is necessary to have interdisciplinary work between the medical team that performs the transplantation and those promoting the primary care to diagnose the disease early and treat it effectively.

Expanded CAG/CTG repeats in schizophrenia. A study of clinical correlates.

BACKGROUND: Schizophrenia is associated with expanded CAG/CTG trinucleotide repeats. We wished to determine whether the presence of such expansions correlated with specific subsyndromes or other clinical features of schizophrenia. METHOD: Seventy patients from England and Wales and 44 patients from Portugal with a DSM-III-R diagnosis of schizophrenia were rated on the OPCRIT checklist. Patient's maximum CAG/CTG repeat length was measured using repeat expansion detection (RED). Significant differences were sought for repeat lengths in subjects categorised according to dimensional and categorical schizophrenia subsyndromes, affective episodes, individual symptoms, and a range of demographic variables. RESULTS: Maximum CAG/CTG repeat length did not differ significantly for any of the clinical or demographic variables studied. CONCLUSION: There are no subsyndromes or other clinical features of schizophrenia associated with CAG/CTG repeat expansion. Therefore, the identification of the gene(s) that contain expanded CAG/CTG repeats and which are associated with schizophrenia is unlikely to be facilitated at present by using any subsyndromes of schizophrenia as phenotypes.

Parameters influencing the expression of IgA antibodies in tears.

Rats were immunized repeatedly with dinitrophenylated type III pneumococcal vaccine by the intravenous (IV), subcutaneous (SC), gastrointestinal (GI), or ocular/topical (OT) routes at biweekly intervals. IgA anti-DNP antibodies were measured in serum, tears, saliva, bronchial, and intestinal washings, obtained 7 days after the third and sixth immunizations, using a solid phase radioimmunoassay. The GI route most effective at eliciting and maintaining IgA antibody responses in tears. The OT group displayed markedly diminished IgA response frequencies and antibody levels in tears following prolonged immunization. These data show that repeated central mucosal (gastrointestinal associated lymphoid tissue) stimulation maintains a local IgA response in tears, while continued topical antigen stimulation does not. Isoelectric focusing was used to probe the spectral complexity of the IgA antibodies of individual animals undergoing GI and OT immunization. The reduction of spectral complexity and the decreased responses following OT immunization appear to reflect a diminution of IgA antibody producing cells in the lacrimal gland. The concomitant changes in spectral components and maintenance of responsiveness of the GI group suggests that central mucosal site stimulation provides the lacrimal compartment with a continuous but variable population of IgA antibody producing cells.

The induction and expression of IgA anti-DNP antibodies in rat bile and secretions.

Pregnant rats were immunized with dinitrophenylated type III-pneumococcal vaccine by the intravenous, gastric, or intramammary routes. Anti-DNP antibody responses in the IgA, IgG and IgM isotypes were measured in serum, secretions and bile. Gastric intubation was most effective at eliciting IgA antibody responses in bile and secretions, whereas the other routes were more effective at inducing IgG responses in serum and bile. IgM antibody responses were infrequent and were found in fluids most closely associated with the immunization route. Isoelectric focusing studies of IgA antibodies appearing in secretions and bile revealed that the gastric route consistently elicited antibody spectrotypes with shared components. Intravenous and intramammary immunization resulted in IgA spectrotypes possessing less homology, suggesting that these protocols lead to independent antibody responses triggered in spleen, draining lymph nodes, or secretory sites. After gastric stimulation, the appearance of IgA antibodies with identical spectral components in secretions and bile favours the concept that IgA precursor cells with identical clonotype potential migrate from the gastrointestinal area to secretory sites. Antibody expression in bile appears to result from the selective transfer of IgA populations gaining access to serum after synthesis at a secretory site.

Molecular diversity of secretory IgA anti-DNP antibodies elicited in rat bile.

Dinitrophenylated-type III pneumococcus has been used to induce biliary IgA anti-DNP antibody responses in rats. A solid phase radioimmunoassay was employed to quantitate the biliary IgA anti-DNP antibodies after subcutaneous, i.v., or intragastric immunization. All routes were shown to effectively elicit biliary IgA antibody responses. The microscale sucrose isoelectric focusing technique was employed to assess molecular diversity of the secretory IgA anti-DNP antibodies in bile. Subcutaneous and intragastric immunization resulted in complex antibody spectrotypes whereas i.v. immunization yielded restricted antibody spectrotypes, demonstrating that the route of immunization influenced the molecular diversity of the biliary secretory IgA antibodies. These findings are discussed in terms of mechanisms governing the induction of secretory antibodies.

A common mucosal immune system. Antibody expression in secretions following gastrointestinal stimulation.

Isoelectric focusing was used to probe the expression of IgA anti-DNP antibodies in secretions of rats receiving gastrointestinal immunization. The identity of the IgA antibody spectrotypes suggest that cells with identical clonotype potential seed various secretory surfaces following gastrointestinal stimulation. The data are discussed in terms of a common mucosal immune system linked by migrating populations of IgA precursor cells.