Molecular characterisation and evolutionary relationships of a potyvirus infecting Crotalaria in Brazil - Brief report

The 3' terminal genomic region of a potyvirus causing mosaic disease in several Crotalaria species has been cloned and sequenced. Comparisons of the nucleotide and deduced amino acid (aa) sequences of the cloned cDNA with those from other potyviruses show that the Crotalaria-infecting virus (designated Crotalaria mosaic virus; CrMV) is closely related to Cowpea aphid-borne mosaic virus (CABMV). Maximum identity (95.4%) at the coat protein (CP) aa level was observed between CrMV and a Brazilian strain of CABMV. Phylogenetic analyses derived from the sequence alignments of the CP and 3' untranslated region confirmed the identification of CrMV as a strain of CABMV and the name CABMV-Cr is suggested.

Bootstrap confidence regions for canonical variates: Application to studies of evolutionary differentiation

Theory recently developed to construct confidence regions based on the parametric bootstrap is applied to add inferential information to graphical displays of sample centroids in canonical variate analysis. Problems of morphometric differentiation among subspecies and species are addressed using numerical resampling procedures.

Phylogenetic and evolutionary aspects of Paracoccidioides brasiliensis reveal a long coexistence with animal hosts that explain several biological features of the pathogen

The habitat of the mycelial saprobic form of Paracoccidio ides brasiliensis, which produces the infectious propagula, has not been determined and has proven difficult for mycologists to describe. The fungus has been rarely isolated from the environment, the disease has a prolonged latency period and no outbreaks have been reported. These facts have precluded the adoption of preventive measures to avoid infection. The confirmation of natural infections in nine-banded armadillos (Dasypus novemcinctus) with P. brasiliensis, in high frequency and wide geographic distribution, has opened new avenues for the study and understanding of its ecology. Armadillos belong to the order Xenarthra, which has existed in South America ever since the Paleocene Era (65 million years ago), when the South American subcontinent was still a detached land, before the consolidation of what is now known as the American continent. on the other hand, strong molecular evidence suggests that P. brasiliensis and other dimorphic pathogenic fungi - such as Blastomyces dermatitidis, Coccidioides immitis and Histoplasma capsulatum - belong to the family Onygenaceae sensu Into (order Onygenales, Ascomycota), which appeared around 150 million years ago.P. brasiliensis ecology and relation to its human host are probably linked to the fungal evolutionary past, especially its long coexistence with and adaptation to animal hosts other than Homo sapiens, of earlier origin. Instead of being a blind alley, the meaning of parasitism for dimorphic pathogenic fungi should be considered as an open two-way avenue, in which the fungus may return to the environment, therefore contributing to preserve its teleomorphic (sexual) and anamorphic (asexual) forms in a defined and protected natural habitat. (c) 2006 Elsevier B.V. All rights reserved.

An evolutionary algorithm for the one-dimensional cutting stock problem

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Othonella araguaiana (Bivalvia, Megadesmidae) from the Corumbatai Formation (Midlle [Middle] Permian), Eastern Margin of the Parana Basin: systematic, evolutionary and biostratigraphic significances.

In this study, the occurrence of Othonella araguaiana Mendes, a rare bivalve species is reported for the first time in the Pinzonella illusa biozone, Middle Permian Corumbatai Formation, in the State of São Paulo. This species was originally described in coeval rocks of the Estrada Nova Formation (= Corumbatai) from the Alto Araguaia and Alto Garcas regions, State of Mato Grosso. The specimens of O. araguaiana were found in the base of a bioclastic sandstone bed, a proximal tempestite, in the middle of the Corumbatai Formation, in the city of Rio Claro, São Paulo State. The silicified shells and internal molds are well preserved, showing impressions of muscle scars and other internal anatomic characters (e.g., hinge), never illustrated by previous authors. In his original description, Mendes (1963) called attention to the similarity between O. araguaiana and Terraia aequilateralis, a common veneroid of the Corumbatai Formation. Conversely, Runnegar and Newell (1971) suggested that O. araguaiana belongs to Megadesmidae, being a junior synonym of Plesiocyprinella carinata (the commonest megadesmid of the Passa Dois Group). Our study indicates that O. araguaiana is indeed a megadesmid, but is distinct from the P. carinata. The new occurrence of O. araguaiana demonstrates that a) the paleobiogeographic distribution of this species is wider than previously thought (that it was restricted to the northern part of Parana Basin, Mato Grosso State); b) the molluscan fauna of the Corumbatai Formation (P. illusa biozone) in the State of São Paulo is more diverse and dominated by megadesmids; and c) the composition of the molluscan fauna of the Corumbatai Formation in Alto GarYas, State of Mato Grosso, is essentially the same as that of the P. illusa biozone of the eastern margin of the Parana Basin.

Paracoccidioidomycosis: A comparative study of the evolutionary serologic, clinical and radiologic results for patients treated with ketoconazole or amphotericin B plus sulfonamides

A comparative study of two groups of patients with paracoccidioidomycosis was carried out with the objective of comparing the evolutionary serologic, clinical and radiologic results after 6, 12, 15 and 18 months of treatment with ketoconazole (22 patients) or amphotericin B plus sulfonamides (32 patients). The serologic data analyzed as a whole showed a tendency to sharper drops in antibody titers in the patients treated with ketoconazole. Clinically patients treated with ketoconazole fared better but the differences were not statistically significant. No statistical difference was detected between groups in terms of the results of radiologic evolution. © 1985 Martinus Nijhoff/Dr W. Junk Publishers.

Planning of secondary distribution circuits through evolutionary algorithms

In this work, the planning of secondary distribution circuits is approached as a mixed integer nonlinear programming problem (MINLP). In order to solve this problem, a dedicated evolutionary algorithm (EA) is proposed. This algorithm uses a codification scheme, genetic operators, and control parameters, projected and managed to consider the specific characteristics of the secondary network planning. The codification scheme maps the possible solutions that satisfy the requirements in order to obtain an effective and low-cost projected system-the conductors' adequate dimensioning, load balancing among phases, and the transformer placed at the center of the secondary system loads. An effective algorithm for three-phase power flow is used as an auxiliary methodology of the EA for the calculation of the fitness function proposed for solutions of each topology. Results for two secondary distribution circuits are presented, whereas one presents radial topology and the other a weakly meshed topology. © 2005 IEEE.

Strong selection against hybrids at a hybrid zone in the Ensatina ring species complex and its evolutionary implications

The analysis of interactions between lineages at varying levels of genetic divergence can provide insights into the process of speciation through the accumulation of incompatible mutations. Ring species, and especially the Ensatina eschscholtzii system exemplify this approach. The plethodontid salamanders E. eschscholtzii xanthoptica and E. eschscholtzii platensis hybridize in the central Sierran foothills of California. We compared the genetic structure across two transects (southern and northern Calaveras Co.), one of which was resampled over 20 years, and examined diagnostic molecular markers (eight allozyme loci and mitochondrial DNA) and a diagnostic quantitative trait (color pattern). Key results across all studies were: (1) cline centers for all markers were coincident and the zones were narrow, with width estimates of 730 m to 2000 m; (2) cline centers at the northern Calaveras transect were coincident between 1981 and 2001, demonstrating repeatability over five generations; (3) there were very few if any putative F1s, but a relatively high number of backcrossed individuals in the central portion of transects: and (4) we found substantial linkage disequilibrium in all three studies and strong heterozygote deficit both in northern Calaveras, in 2001, and southern Calaveras. Both linkage disequilibrium and heterozygote deficit showed maximum values near the center of the zones. Using estimates of cline width and dispersal, we infer strong selection against hybrids. This is sufficient to promote accumulation of differences at loci that are neutral or under divergent selection, but would still allow for introgression of adaptive alleles. The evidence for strong but incomplete isolation across this centrally located contact is consistent with theory suggesting a gradual increase in postzygotic incompatibility between allopatric populations subject to divergent selection and reinforces the value of Ensatina as a system for the study of divergence and speciation at multiple stages. © 2005 The Society for the Study of Evolution. All rights reserved.

Study of the venom glands in Ectatomma quadridens (Hymenoptera: Formicidae). Evolutionary hypothesis in subfamily ponerinae

The venom glands of worker ants of the species Ectatomma quadridens morphologically resemble an elongated sac or reservoir ending in a narrower portion that has the function of releasing the secretion to the exterior. Two external secretory filaments are individually inserted into the proximal portion of the gland and end inside the convoluted gland. The venom gland of workers of E. quadridens is, therefore, morphologically subdivided into four distinct portions: a) sac-shaped reservoir measuring approximately 1mm in length; b) excretory duct, proximal portion of the reservoir that joins the gland to the sting apparatus; c) convoluted gland, final portion of the external secretory filaments located inside the reservoir; and d) two secretory filaments measuring about 2 mm in length; their free extremities end blindly and are individually inserted into the reservoir wall at the proximal region of the venom gland. The histological data showed that the filaments and the convoluted gland are composed of cubic cells of secretory function. The reservoir consists of a simple cubical epithelium externally surrounded by muscle fibers. A thick cuticle internally coats the epithelium of the reservoir. The application of histochemical tests allowed us to establish that the final secretion of the venom gland of Ectatomma quadridens is of glycoproteic nature. This secretion undergoes several modifications at the secretory filaments, at the convoluted gland, and in the reservoir before reaching the excretory duct, the point at which the secretion is released in its final composition, namely the venom. Based on the differences among various Ponerinae species we propose a hypothesis suggesting a probable evolutionary process that the venom glands of members of this subfamily might have undergone.

Evolutionary modeling of larval dispersal in blowflies using non-uniform cellular automata

When the food supply flnishes, or when the larvae of blowflies complete their development and migrate prior to the total removal of the larval substrate, they disperse to find adequate places for pupation, a process known as post-feeding larval dispersal. Based on experimental data of the Initial and final configuration of the dispersion, the reproduction of such spatio-temporal behavior is achieved here by means of the evolutionary search for cellular automata with a distinct transition rule associated with each cell, also known as a nonuniform cellular automata, and with two states per cell in the lattice. Two-dimensional regular lattices and multivalued states will be considered and a practical question is the necessity of discovering a proper set of transition rules. Given that the number of rules is related to the number of cells in the lattice, the search space is very large and an evolution strategy is then considered to optimize the parameters of the transition rules, with two transition rules per cell. As the parameters to be optimized admit a physical interpretation, the obtained computational model can be analyzed to raise some hypothetical explanation of the observed spatiotemporal behavior. © 2006 IEEE.

Respiratory chemoreceptor function in vertebrates - Comparative and evolutionary aspects

The sensing of blood gas tensions and/or pH is an evolutionarily conserved, homeostatic mechanism, observable in almost all species studied from invertebrates to man. In vertebrates, a shift from the peripheral O2-oriented sensing in fish, to the central CO2/pH sensing in most tetrapods reflects the specific behavioral requirements of these two groups whereby, in teleost fish, a highly O2-oriented control of breathing matches the ever-changing and low oxygen levels in water, whilst the transition to air-breathing increased the importance of acid-base regulation and O2-related drive, although retained, became relatively less important. The South American lungfish and tetrapods are probably sister groups, a conclusion backed up by many similar features of respiratory control. For example, the relative roles of peripheral and central chemoreceptors are present both in the lungfish and in land vertebrates. In both groups, the central CO2/pH receptors dominate the ventilatory response to hypercarbia (60-80), while the peripheral CO2/pH receptors account for 20-30. Some basic components of respiratory control have changed little during evolution. This review presents studies that reflect the current trends in the field of chemoreceptor function, and several laboratories are involved. An exhaustive review on the previous literature, however, is beyond the intended scope of the article. Rather, we present examples of current trends in respiratory function in vertebrates, ranging from fish to humans, and focus on both O2 sensing and CO2 sensing. As well, we consider the impact of chronic levels of hypoxia - a physiological condition in fish and in land vertebrates resident at high elevations or suffering from one of the many cardiorespiratory disease states that predispose an animal to impaired ventilation or cardiac output. This provides a basis for a comparative physiology that is informative about the evolution of respiratory functions in vertebrates and about human disease. Currently, most detail is known for mammals, for which molecular biology and respiratory physiology have combined in the discovery of the mechanisms underlying the responses of respiratory chemoreceptors. Our review includes new data on nonmammalian vertebrates, which stresses that some chemoreceptor sites are of ancient origin.

Distribution network reconfiguration using an efficient evolutionary algorithm

Network reconfiguration is an important tool to optimize the operating conditions of a distribution system. This is accomplished modifying the network structure of distribution feeders by changing the open/close status of sectionalizing switches. This not only reduces the power losses, but also relieves the overloading of the network components. Network reconfiguration belongs to a complex family of problems because of their combinatorial nature and multiple constraints. This paper proposes a solution to this problem, using a specialized evolutionary algorithm, with a novel codification, and a brand new way of implement the genetic operators considering the problem characteristics. The algorithm is presented and tested in a real distribution system, showing excellent results and computational efficiency. © 2007 IEEE.

Mitochondrial genome sequence of the Brazilian luminescent click beetle Pyrophorus divergens (Coleoptera: Elateridae): Mitochondrial genes utility to investigate the evolutionary history of Coleoptera and its bioluminescence

The Coleoptera order is the richest group among Metazoa, but its phylogenetics remains incompletely understood. Among Coleoptera, bioluminescence is found within the Elateroidea, but the evolution of this character remains a mystery. Mitochondrial DNA has been used extensively to reconstruct phylogenetic relationships, however, the evolution of a single gene does not always correspond to the species evolutionary history and the molecular marker choice is a key step in this type of analysis. To create a solid basis to better understand the evolutionary history of Coleoptera and its bioluminescence, we sequenced and comparatively analyzed the mitochondrial genome of the Brazilian luminescent click beetle Pyrophorus divergens (Coleoptera: Elateridae). © 2007 Elsevier B.V. All rights reserved.

Evolutionary heuristic to determine future land use

In the spatial electric load forecasting, the future land use determination is one of the most important tasks, and one of the most difficult, because of the stochastic nature of the city growth. This paper proposes a fast and efficient algorithm to find out the future land use for the vacant land in the utility service area, using ideas from knowledge extraction and evolutionary algorithms. The methodology was implemented into a full simulation software for spatial electric load forecasting, showing a high rate of success when the results are compared to information gathered from specialists. The importance of this methodology lies in the reduced set of data needed to perform the task and the simplicity for implementation, which is a great plus for most of the electric utilities without specialized tools for this planning activity. © 2008 IEEE.