157 research outputs found
Genética da Castanheira (bertholletia Excelsa, Lecythidacea): Estudo da Variabilidade do Genoma do Cloroplasto.
Genetics of cytosolic phosphoglucose isomerase (PGI) variation in the Amazonian tree Pseudobombax munguba (Bombacaceae)
A genetic analysis of cytosolic phosphoglucose isomerase (PGI) variation in the tropical tree Pseudobombax munguba (Bombacaceae) was carried out in one population from Central Amazon. It was shown that cytosolic PGI variation is controlled by two diallelic loci (Pgi-2 and Pgi-3). All nine possible enzyme phenotypes produced by allelic variation at these two loci were easily identified on gels stained for PGI. Progeny analysis from cross-pollinated families revealed that the two loci assorted independently and exhibited disomic inheritance, suggesting that allopolyploidy may have been the cause of the duplication of the cytosolic PGI gene in this species. ©1996 The Genetical Society of Great Britain
Prey preference of the common vampire bat (Desmodus rotundus, Chiroptera) using molecular analysis
Morphological identification of prey fragments in vampire bat feces is impossible because of an exclusively blood-based diet. Therefore, studies of their foraging ecology require innovative approaches. We investigated the diet of Desmodus rotundus using a PCR-restriction fragment length polymorphism (RFLP) molecular method by amplifying the cytochrome b mitochondrial gene (380 bp) from DNA fecal samples collected from captive bats fed with blood from chickens, cattle, pigs, dogs, and humans - the 5 most frequently attacked prey species in rural areas of the Brazilian Amazonia. The prey preference of the vampire bat was investigated in 18 riverine villages, where the availability of domestic animals to bats was quantified. Prey DNA amplified from fecal samples exhibited no visible signals of vampire bat DNA. A PCR - RFLP flowchart and a combination of 2 DNA restriction enzymes allowed the direct identification of prey to species level. The enzymes' restriction profile did not overlap with those of vampire bats or wild mammal and avian species. Chickens were the most attacked prey species (61.4% of the identifications, n = 27), but pigs were highly preferred in relation to prey availability. This suggests a preference for mammalian blood in D. rotundus diet, with chickens exploited as a secondary food source. No wild vertebrate species was identified in the fecal samples, indicating that vampire bats are selectively feeding on the blood of domesticated animals, probably because they are more predictable and easily accessed resources. © 2015 American Society of Mammalogists
Contrasting patterns of genetic structure in Caryocar (Caryocaraceae) congeners from flooded and upland Amazonian forests
In the present study, we compare the genetic structure of a flooded forest tree Caryocar microcarpum and a terra firme forest tree Caryocar villosum in the lower Rio Negro region and test the hypothesis that the Rio Negro, the largest tributary on the left bank of the Amazon River, has been acting as a geographical barrier to gene flow between populations from the left and right banks. Seventeen adult individuals on the left bank and 27 on the right bank of Rio Negro were sampled for C. microcarpum, whereas 27 on the left and 20 on the right bank were sampled for C. villosum. Two chloroplast DNA regions were sequenced: the intron of trnL gene and the intergenic region between psbA and trnH genes; and all individuals were genotyped using ten microsatellite loci. The trnL intron and psbA-trnH intergenic spacer generated fragments of 459 bp and 424 bp, respectively. For C. microcarpum, six haplotypes were identified for trnL and seven for psbA-trnH. By contrast, only one haplotype was found for C. villosum for both sequences. The results obtained showed that the Rio Negro has not been a barrier to gene flow by pollen and seeds for either species. No genetic differentiation and a high migration rate between populations from the left and right banks of the Rio Negro were detected for the chloroplast sequences and nuclear microsatellites, for both C. villosum and C. microcarpum. Although the two analysed sequences showed a sharp topology difference, both indicated that multiple lineages may have contributed to the origin of C. microcarpum populations in the Rio Negro basin. Nevertheless, for C. villosum, from terra firme, the results obtained may provide evidence of a recent expansion of one maternal lineage from an ancient relic population surviving in one of the few moist forest refuges of the Guiana Shield during extended droughts of the glacial periods. We hypothesize that the contrasting environments colonized by this congener pair may have played an important role in shaping the genetic structure of both species. © 2009 The Linnean Society of London
Mendelian inheritance, linkage and genotypic disequilibrium in microsatellite loci isolated from Hymenaea courbaril (Fabaceae)
Brief Note Mendelian inheritance, linkage and genotypic disequilibrium in microsatellite loci isolated from Hymenaea courbaril (Leguminosae)
Conservation implications of the mating system of the Pampa Hermosa landrace of peach palm analyzed with microsatellite markers
Peach palm (Bactris gasipaes) is cultivated by many indigenous and traditional communities from Amazonia to Central America for its edible fruits, and is currently important for its heart-of-palm. The objective of this study was to investigate the mating system of peach palm, as this is important for conservation and breeding. Eight microsatellite loci were used to genotype 24 open-pollinated progenies from three populations of the Pampa Hermosa landrace maintained in a progeny trial for genetic improvement. Both the multi-locus outcrossing rates (0.95 to 0.99) and the progeny level multi-locus outcrossing rates (0.9 to 1.0) were high, indicating that peach palm is predominantly allogamous. The outcrossing rates among relatives were significantly different from zero (0.101 to 0.202), providing evidence for considerable biparental inbreeding within populations, probably due to farmers planting seeds of a small number of open-pollinated progenies in the same plot. The correlations of paternity estimates were low (0.051 to 0.112), suggesting a large number of pollen sources (9 to 20) participating in pollination of individual fruit bunches. Effective population size estimates suggest that current germplasm collections are insufficient for long-term ex situ conservation. As with most underutilized crops, on farm conservation is the most important component of an integrated conservation strategy. © 2015, Sociedade Brasileira de Genética. Printed in Brazil
Programação da produção: Otimização de Layouts Industriais
O problema conhecido na literatura como “Facility layout problem (FLP)”, em que se pretende determinar a disposição de recursos de produção e a sua interação num determinado espaço, é um problema estratégico para a implementação do chão de fábrica de uma empresa pelo impacto que tem na performance da produção.
O problema consiste em encontrar um posicionamento único entre instalações (departamentos, máquinas, células de produção, armazéns, etc.) e localizações no chão de fábrica, de forma a otimizar um ou mais objetivos de produção. O objetivo da criação de layout consiste na otimização do espaço existente, minimização do tempo de produção, redução do custo de manuseamento de matérias, aumento do grau de flexibilidade, entre outros.
A solução do problema deverá especificar a localização relativa de cada departamento (layout em bloco) e numa fase posterior poderá especificar o layout detalhado dentro de cada departamento.
Na presente tese serão apresentados alguns modelos matemáticos para criação de um layout, neste caso vamos usar uma formulação matemática Quadratic Assignment Problem (QAP), uma formulação matemática Mixed Integer Programming (MIP) e uma heurística de Particle Swarm Optimization (PSO) para resolver problemas de layout.
Todas estas formulações e modelos serão postos em prática para a resolução de problemas fictícios.
Numa primeira abordagem iremos resolver problemas fictícios onde abordaremos a formulação QAP para problemas de atribuição de espaço de duas dimensões (x,y) e MIP e em seguida iremos usar a heurística PSO para a resolução de problemas em escala maior e real.The problem known in the literature as "Facility layout problem (FLP)", which is intended to determine the physical layout of industrial facilities, is a strategic problem for the implementation of a company by the impact it has on the production performance.
The problem is to find an unambiguous allocation between facilities (departments, machines, production cells, warehouses, etc.) and locations on the shop floor in order to optimize one or more production goals. The objectives often considered are the optimization of the space, minimizing production time, reduce the handling costs of materials, increased flexibility, among others.
The solution of the problem should specify the relative location of each department (block layout) and at a later stage it can specify the detailed layout within each department.
In this thesis will be presented some methods of resolution in this case we use a discrete Quadratic Assignment formulation (QAP), a Mixed Integer Linear Programming formulation (MIP) and a Particle Swarm Optimization heuristic (PSO) to solve layout problems. All these heuristics will be implemented for solving fictitious problems.
In a first approach we will solve simpler problems where we use the QAP and MIP formulation and following we will use the PSO heuristic to solve problems on a larger scale
White sand vegetation in an Amazonian lowland under the perspective of a young geological history
White sand vegetation in an Amazonian lowland under the perspective of a young geological history
What controls the formation of patchy substrates of white sand vegetation in the Amazonian lowlands is still unclear. This research integrated the geological history and plant inventories of a white sand vegetation patch confined to one large fan-shaped sandy substrate of northern Amazonia, which is related to a megafan environment. We examined floristic patterns to determine whether abundant species are more often generalists than the rarer one, by comparing the megafan environments and older basement rocks. We also investigated the pattern of species accumulation as a function of increasing sampling effort. All plant groups recorded a high proportion of generalist species on the megafan sediments compared to older basement rocks. The vegetation structure is controlled by topographic gradients resulting from the smooth slope of the megafan morphology and microreliefs imposed by various megafan subenvironments. Late Pleistocene-Holocene environmental disturbances caused by megafan sedimentary processes controlled the distribution of white sand vegetation over a large area of the Amazonian lowlands, and may have also been an important factor in species diversification during this period. The integration of geological and biological data may shed new light on the existence of many patches of white sand vegetation from the plains of northern Amazonia. © 2019, Academia Brasileira de Ciencias. All rights reserved
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