803 research outputs found
Monitoramento da população de Rhynchophorus palmarum em plantações de dendezeiros no municÃpio de Igarapé-Açu, PA.
Monitoramento da população do besouro Rhynchophorus palmarum em dendezais no municÃpio de Igarapé-Açu, Pará.
bitstream/item/60313/1/CPATU-PA198.pd
Avaliação de iscas e armadilhas para captura de Rhynchophorus palmarum em dendezais.
bitstream/item/57488/1/CPATU-BP200.pd
The role of retailer's performance in optimal wholesale price discount policies
The main goal of this paper is to model the effects of wholesale price control on manufacturer’s profit, taking explicitly into account
the retailer’s sales motivation and performance. We consider a stylized distribution channel where a manufacturer sells a single kind of
good to a single retailer. Wholesale price discounts are assumed to increase the retailer’s motivation thus improving sales. We study the
manufacturer’s profit maximization problem as an optimal control model where the manufacturer’s control is the discount on wholesale
price and retailer’s motivation is one of the state variables. In particular in the paper we prove that an increasing discount policy is optimal
for the manufacturer when the retailer is not efficient while efficient retailers may require to decrease the trade discounts at the end of
the selling period. Computational experiments point out how the discount on wholesale price passed by the retailer to the market (passthrough)
influences the optimal profit of the manufacturer
High-resolution genetic map and QTL analysis of growth-related traits of Hevea brasiliensis cultivated under suboptimal temperature and humidity conditions
Rubber tree (Hevea brasiliensis) cultivation is the main source of natural rubber worldwide and has been extended to areas with suboptimal climates and lengthy drought periods; this transition affects growth and latex production. High-density genetic maps with reliable markers support precise mapping of quantitative trait loci (QTL), which can help reveal the complex genome of the species, provide tools to enhance molecular breeding, and shorten the breeding cycle. In this study, QTL mapping of the stem diameter, tree height, and number of whorls was performed for a full-sibling population derived from a GT1 and RRIM701 cross. A total of 225 simple sequence repeats (SSRs) and 186 single-nucleotide polymorphism (SNP) markers were used to construct a base map with 18 linkage groups and to anchor 671 SNPs from genotyping by sequencing (GBS) to produce a very dense linkage map with small intervals between loci. The final map was composed of 1,079 markers, spanned 3,779.7 cM with an average marker density of 3.5 cM, and showed collinearity between markers from previous studies. Significant variation in phenotypic characteristics was found over a 59-month evaluation period with a total of 38 QTLs being identified through a composite interval mapping method. Linkage group 4 showed the greatest number of QTLs (7), with phenotypic explained values varying from 7.67 to 14.07%. Additionally, we estimated segregation patterns, dominance, and additive effects for each QTL. A total of 53 significant effects for stem diameter were observed, and these effects were mostly related to additivity in the GT1 clone. Associating accurate genome assemblies and genetic maps represents a promising strategy for identifying the genetic basis of phenotypic traits in rubber trees. Then, further research can benefit from the QTLs identified herein, providing a better understanding of the key determinant genes associated with growth of Hevea brasiliensis under limiting water conditions
Linkage disequilibrium and population structure in wild and cultivated populations of rubber tree (Hevea brasiliensis).
Abstract: Among rubber tree species, which belong to the Hevea genus of the Euphorbiaceae family, Hevea brasiliensis (Willd. ex Adr.de Juss.) Muell. Arg. is the main commercial source of natural rubber production worldwide. Knowledge of the population structure and linkage disequilibrium (LD) of this species is essential for the efficient organization and exploitation of genetic resources. Here, we obtained single-nucleotide polymorphisms (SNPs) using a genotyping-by-sequencing (GBS) approach and then employed the SNPs for the following objectives: (i) to identify the positions of SNPs on a genetic map of a segregating mapping population, (ii) to evaluate the population structure of a germplasm collection, and (iii) to detect patterns of LD decay among chromosomes for future genetic association studies in rubber tree. A total of 626 genotypes, including both germplasm accessions (368) and individuals from a genetic mapping population (254), were genotyped. A total of 77,660 and 21,283 SNPs were detected by GBS in the germplasm and mapping populations, respectively. The mapping population, which was previously mapped, was constructed with 1,062 markers, among which only 576 SNPs came from GBS, reducing the average interval between two adjacent markers to 4.4 cM. SNPs from GBS genotyping were used for the analysis of genetic structure and LD estimation in the germplasm accessions. Two groups, which largely corresponded to the cultivated and wild populations, were detected using STRUCTURE and via principal coordinate analysis. LD analysis, also using the mapped SNPs, revealed that non-random associations varied along chromosomes, with regions of high LD interspersed with regions of low LD. Considering the length of the genetic map (4,693 cM) and the mean LD (0.49 for cultivated and 0.02 for wild populations), a large number of evenly spaced SNPs would be needed to perform genome-wide association studies in rubber tree, and the wilder the genotypes used, the more difficult the mapping saturation
Dry port location optimization to foster sustainable regional development
The saturation of hinterland accentuates adverse environmental impacts and socio-spatial conflicts, demanding logistical alternatives. As a solution, the dry port enables the decentralization of customs, handling, and storage operations, which mitigates part of the problems, in addition to stimulating the economy in the region where it operates. Thus, its location is crucial for the efficiency of import and export logistic systems. This paper aimed to evaluate the spatial distribution of dry ports in Minas Gerais, Brazil, and to identify the best locations for a new installation. The methodology put together two recognized methods for location definition: the Spatial Multicriteria Analysis and the Location-Allocation Problem. The first, in line with the most current practices in transportation planning, integrated social, environmental and technical criteria. The second adopted the first’s result as weighted demand and applied a metaheuristic to solve an optimization problem. Findings show the regional disparity and the deficiency of logistic infrastructures in the north of Minas Gerais. All scenarios point to the Montes Claros region as a candidate for the installation of a dry port. The possibility of reconciling society, environment and economy in infrastructure planning was demonstrated.
 A saturação das zonas de influência portuária acentua impactos ambientais e conflitos socioespaciais, demandando alternativas logÃsticas. O porto seco possibilita a descentralização de atividades aduaneiras, de manuseio e armazenagem, mitigando parte dos problemas, além de estimular a economia na região onde é inserido. Dessa forma, a sua localização é crucial para a eficiência dos sistemas logÃsticos de importação e exportação. O objetivo deste trabalho foi avaliar a distribuição espacial dos portos secos em Minas Gerais e identificar os melhores locais para uma nova instalação. A metodologia agregou dois métodos reconhecidos de definição locacional: a Análise Multicritério Espacial e o Problema de Localização-Alocação. O primeiro, em consonância com as práticas mais atuais no planejamento de transporte, integrou critérios sociais, ambientais e técnicos. O segundo, adotou o resultado da análise multicritério como demanda ponderada e aplicou uma meta heurÃstica para solução do problema de otimização. Os resultados evidenciam a disparidade regional e a deficiência de infraestruturas logÃsticas no norte de Minas. Todos os cenários apontam a região de Montes Claros como candidata à instalação de um porto seco. A possibilidade de conciliar sociedade, ambiente e economia no planejamento de infraestrutura foi demonstrada
Randomized double-blind clinical trial of a new human epoetin versus a commercially available formula for anemia control in patients on hemodialysis
OBJECTIVES: Anemia is a common complication among chronic kidney disease patients on hemodialysis, occurring mostly due to erythropoietin deficiency. This randomized noninferiority trial sought to compare the efficacy and safety of a new epoetin formulation developed by Bio-Manguinhos, a biologics manufacturer affiliated with the Brazilian government, with those of a commercially available product currently used in Brazil (a biosimilar epoetin formulation). METHODS: The sample size needed to enable demonstration of noninferiority with a statistical power of 85% for a between-group difference in hemoglobin levels of no more than 1.5 g/dL was calculated. In total, 74 patients were randomly assigned to receive the epoetin formulation from Bio-Manguinhos (n = 36) or the biosimilar epoetin formulation (n = 38) in a double-blind fashion. The inclusion criteria were current epoetin therapy and stable hemoglobin levels for at least 3 months prior to the study. The primary and secondary outcomes were mean monthly hemoglobin levels and safety, respectively. The dose was calculated according to international criteria and adjusted monthly in both groups according to hemoglobin levels and at the assistant physicians' discretion. Iron storage was estimated at baseline and once monthly. Clinicaltrials.gov: NCT01184495. RESULTS: The study was conducted for 6 months after randomization. The mean baseline hemoglobin levels were 10.9±1.2 and 10.96±1.2 g/dL (p = 0.89) in the Bio-Manguinhos epoetin and biosimilar epoetin groups, respectively. During the study period, there was no significant change in hemoglobin levels in either group (p = 0.055, ANOVA). The epoetin from Bio-Manguinhos was slightly superior in the last 3 months of follow-up. The adverse event profiles of the two formulations were also similar. CONCLUSIONS: The epoetin formulations tested in this study are equivalent in efficacy and safety
Exercise training prevents skeletal muscle damage in an experimental sepsis model
OBJECTIVE: Oxidative stress plays an important role in skeletal muscle damage in sepsis. Aerobic exercise can decrease oxidative stress and enhance antioxidant defenses. Therefore, it was hypothesized that aerobic exercise training before a sepsis stimulus could attenuate skeletal muscle damage by modulating oxidative stress. Thus, the aim of this study was to evaluate the effects of aerobic physical preconditioning on the different mechanisms that are involved in sepsis-induced myopathy. METHODS: Male Wistar rats were randomly assigned to either the untrained or trained group. The exercise training protocol consisted of an eight-week treadmill program. After the training protocol, the animals from both groups were randomly assigned to either a sham group or a cecal ligation and perforation surgery group. Thus, the groups were as follows: sham, cecal ligation and perforation, sham trained, and cecal ligation and perforation trained. Five days after surgery, the animals were euthanized and their soleus and plantaris muscles were harvested. Fiber cross-sectional area, creatine kinase, thiobarbituric acid reactive species, carbonyl, catalase and superoxide dismutase activities were measured. RESULTS: The fiber cross-sectional area was smaller, and the creatine kinase, thiobarbituric acid reactive species and carbonyl levels were higher in both muscles in the cecal ligation and perforation group than in the sham and cecal ligation and perforation trained groups. The muscle superoxide dismutase activity was higher in the cecal ligation and perforation trained group than in the sham and cecal ligation and perforation groups. The muscle catalase activity was lower in the cecal ligation and perforation group than in the sham group. CONCLUSION: In summary, aerobic physical preconditioning prevents atrophy, lipid peroxidation and protein oxidation and improves superoxide dismutase activity in the skeletal muscles of septic rats
Pulsed ultrasound associated with gold nanoparticle gel reduces oxidative stress parameters and expression of pro-inflammatory molecules in an animal model of muscle injury
- …