Um Problema de Escalonamento de Trens Usando Programação por Restrições

Neste artigo, Programaçõo por Restrições é aplicada ao problemado Escalonamento de Trens. O objetivo consiste em encontrar o menor tempo para que trens em estações em dois extremos cruzem um percurso pré-definido, evitando o cruzamento com trens em direções opostas. Após modelagem e implementação, os resultados de tempo levantados são aceitáveis, dada a complexidade desta classe de problema. Este resultado fortalece a CP como uma teoria atrativa a ser aplicado a problemas reais

Fertilizer concentration and fertigation frequency: effects on electric conductivity and ions concentration in the soil solution

Fertirrigation allows total control of the amount of applied fertilizers to the soil as a function of crop demand. Fertigation relies on monitoring of soil ions to obtain the sustainability of soil chemical conditions. The continuous evaluation of ions in the soil solution also contributes to the estimation of the cycling rate of chemical elements and nutrient leaching in the field. The objective of this work was (i) to evaluate nitrate, potassium, sodium and electrical conductivity in the soil solution submitted to different concentrations of injection solution and fertigation frequency during one cycle of the "Grande Naine" banana in a non-cohesive Yellow Latosol and (ii) to evaluate the effects of concentration and fertigation frequency on yields of banana crop. The experiment was carried out according to a randomized block design with six treatments and four replications in a 3 x 2 factorial scheme with three concentrations of the injection solution (3, 10 and 15 g L-1) x two fertigation frequencies (3 and 7 days). The treatments influenced the values of the ion concentration in the soil solution in the soil profile corresponding to the depths of 0-0.30 e 0.30-0.60 m. The concentration of the injection solution and the interaction frequency x concentration influenced the electrical conductivity and nitrate concentration of the soil solution. There was no significant effect of the injection solution and fertigation frequency on production variables

Changes in leaf functional traits with leaf age: when do leaves decrease their photosynthetic capacity in Amazonian trees?

Most leaf functional trait studies in the Amazon basin do not consider ontogenetic variations (leaf age), which may influence ecosystem productivity throughout the year. When leaf age is taken into account, it is generally considered discontinuous, and leaves are classified into age categories based on qualitative observations. Here, we quantified age-dependent changes in leaf functional traits such as the maximum carboxylation rate of ribulose-1,5-biphosphate carboxylase/oxygenase (Rubisco) (Vcmax), stomatal control (Cgs%), leaf dry mass per area and leaf macronutrient concentrations for nine naturally growing Amazon tropical trees with variable phenological strategies. Leaf ages were assessed by monthly censuses of branch-level leaf demography; we also performed leaf trait measurements accounting for leaf chronological age based on days elapsed since the first inclusion in the leaf demography, not predetermined age classes. At the tree community scale, a nonlinear relationship between Vcmax and leaf age existed: young, developing leaves showed the lowest mean photosynthetic capacity, increasing to a maximum at 45 days and then decreasing gradually with age in both continuous and categorical age group analyses. Maturation times among species and phenological habits differed substantially, from 8 ± 30 to 238 ± 30 days, and the rate of decline of Vcmax varied from −0.003 to −0.065 μmol CO2 m−2 s−1 day−1. Stomatal control increased significantly in young leaves but remained constant after peaking. Mass-based phosphorus and potassium concentrations displayed negative relationships with leaf age, whereas nitrogen did not vary temporally. Differences in life strategies, leaf nutrient concentrations and phenological types, not the leaf age effect alone, may thus be important factors for understanding observed photosynthesis seasonality in Amazonian forests. Furthermore, assigning leaf age categories in diverse tree communities may not be the recommended method for studying carbon uptake seasonality in the Amazon, since the relationship between Vcmax and leaf age could not be confirmed for all trees

In situ short-term responses of Amazonian understory plants to elevated CO₂

The response of plants to increasing atmospheric CO2 depends on the ecological context where the plants are found. Several experiments with elevated CO2 (eCO2) have been done worldwide, but the Amazonian forest understory has been neglected. As the central Amazon is limited by light and phosphorus, understanding how understory responds to eCO2 is important for foreseeing how the forest will function in the future. In the understory of a natural forest in the Central Amazon, we installed four open-top chambers as control replicates and another four under eCO2 (+250 ppm above ambient levels). Under eCO2, we observed increases in carbon assimilation rate (67%), maximum electron transport rate (19%), quantum yield (56%), and water use efficiency (78%). We also detected an increase in leaf area (51%) and stem diameter increment (65%). Central Amazon understory responded positively to eCO2 by increasing their ability to capture and use light and the extra primary productivity was allocated to supporting more leaf and conducting tissues. The increment in leaf area while maintaining transpiration rates suggests that the understory will increase its contribution to evapotranspiration. Therefore, this forest might be less resistant in the future to extreme drought, as no reduction in transpiration rates were detected.</p

Perfil sorológico do vírus John Cunningham (JCV) em pacientes com esclerose múltipla

Treatment options for multiple sclerosis (MS) have changed over the last few years, bringing about a new category of drugs with more efficient profiles. However, these drugs have come with a whole new profile of potential adverse events that neurologists have to learn well and quickly. One of the most feared complications of these MS treatments is progressive multifocal leukoencephalopathy caused by the reactivation of the John Cunningham virus (JCV). Objective: To identify the serologic profile of JCV in patients with MS. Methods: Data on serum antibodies for JCV were obtained using the enzyme-linked immunosorbent assay provided by the STRATIFY-JCV program. Results: A total of 1,501 blood tests were obtained from 1,102 patients with MS. There were 633 patients (57.1%) who were positive for antibodies for JCV and 469 patients who were negative (42.9%). Twenty-three patients became positive after initially having negative JCV antibody status. The rate of seroconversion was 18.5% over 22 months. Conclusion: The JCV serologic profile and seroconversion in Brazilian patients were similar to those described in other countries.As opções terapêuticas para esclerose múltipla (EM) modificaram-se ao longo dos últimos anos, trazendo uma nova categoria de drogas com melhor perfil de eficácia. No entanto, estas drogas vieram com um novo perfil de potenciais eventos adversos que exigem que o neurologista os reconheça bem e rapidamente. Uma das complicações mais temidas destes tratamentos para a EM é a leucoencefalopatia multifocal progressiva (LEMP), causada pela reativação do vírus John Cunningham (JCV). Objetivo: Identificar o perfil sorológico de JCV em pacientes com EM. Métodos: Dados sorológicos de JCV foram obtidos através do ensaio por enzimas imuno-adsorvidas (ELISA) fornecido pelo programa STRATIFY-JCV. Resultados: Um total de 1.501 testes sanguíneos foram obtidos de 1.102 pacientes com EM. O grupo teve 633 pacientes (57,1%) soropositivos para anticorpos anti-JCV e 469 pacientes negativos (42,9%). Vinte e três pacientes se tornaram posivitos após resultados iniciais negativos para anticorpos anti-JCV. A taxa de soroconversão foi 18,5% em 22 meses. Conclusão: O perfil sorológico do JCV e a soroconversão nos pacientes brasileiros foi semelhante àquela descrita em outros países

Potenciais interações de drogas em pacientes de terapia antirretroviral: uma revisão integrativa: Potential drug interactions in antiretroviral therapy patients: an integrative review

Possíveis interações medicamentosas devem ser levadas em consideração ao selecionar um regime antirretroviral. Uma revisão detalhada dos medicamentos concomitantes pode ajudar na criação de um regime que minimize as interações indesejáveis. O potencial para interações medicamentosas deve ser avaliado quando qualquer novo medicamento (incluindo agentes de venda livre) é adicionado a um regime antirretroviral existente. A maioria das interações medicamentosas com medicamentos antirretroviral é mediada por inibição ou indução do metabolismo hepático de medicamentos. Este estudo trata-se de uma revisão integrativa, cujo objetivo foi compreender as possíveis interações de drogas em pacientes com infecção pelo HIV em processo de terapia antirretroviral. Após análise dos dados, concluiu-se que há riscos reais de interações medicamentosas a partir do uso de 5 ou mais medicamentos, por um tempo superior a seis anos. Os principais riscos apontados nesse sentido foram interferência na resposta terapêutica, aumento de reações adversas toxidade nos sistemas cardiovascular e nervoso central e dificuldades para detecção de resistência do HIV aos medicamentos antirretrovirais

Sepse: avaliação da qualidade do atendimento em setor de urgência e emergência: Sepsis: assessment of the quality of emergency and emergency care

A Sepse corresponde à presença de uma disfunção orgânica fatal provocada por uma resposta anormal do hospedeiro a um processo infeccioso, que pode progredir para um choque séptico. No decorrer dessa pesquisa, cuja metodologia foi a revisão integrativa de literatura, foram utilizados artigos científicos publicados em periódicos nacionais entre os anos de 2015 e 2022, retirados da base de dados Medline e Lilacs, sendo buscados a partir dos descritores: “Sepse”, “Qualidade do atendimento” e “Urgência e Emergência”. Com o objetivo de analisar a efetividade das ações de cuidados de Enfermagem aplicadas ao sepse adulto, a partir da análise de dados reunidos nesta revisão integrativa, foi possível concluir que a implantação de protocolos para o tratamento resultou em melhorias significativas nos indicadores de qualidade nos cuidados com a sepse, a exemplo da melhoria do fluxo e de atenção aos pacientes e redução da mortalidade nos setores de urgência e emergência