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The qualitative problems of observability analysis and identification of critical measurements and critical sets are topics highly addressed in the literature. The analysis of such problems allows one to qualify the available measurements and predicts the extent of the benefits provided by the state estimator. Nevertheless, due to the lack of a concise theoretical approach, important concepts are often overlooked, so one cannot directly relate the existing numerical methods. Thus, based on the Jacobian's fundamental subspaces, this paper presents a unified theoretical framework for qualitative analysis. This approach along with a comprehensive literature review enables a categorization of the existing numerical methods, which are shown to be closely related. Given bases for the subspaces, unified alternative methods are conceived. These methods are independent of the decompositions required to obtain the bases for the subspaces. This paper also proposes a method to estimate the Jacobian's rank, which is used to identify cases prone to be pathological avoiding unnecessary iterations required by numerical observability analysis algorithms. An example shows that in 99.8% of cases the iterations can be dispensed with. Case studies with small systems of 6 and 14 buses are used to present the proposed approaches in a didactic way. [ABSTRACT FROM AUTHOR]

Wastewater services are fundamental for the protection of public health and environment, population well-being and sustainable development of communities. The value of urban water assets represents a major part of all public infrastructures. These assets must be managed rationally and efficiently, justifying investment priorities in a clear and straightforward way. Effective decision-making requires a comprehensive approach allowing the incorporation of desired performance at acceptable risk levels, considering investment and operational costs. Advanced sewer infrastructure asset management (IAM) is key to achieve and ensure adequate future levels of service, in issues such as flooding of urban areas, pollution prevention, balancing performance, risk and cost. The paper illustrates the integration of different support tools and methods by implementation of the AWARE-P procedure for planning IAM, demonstrated by the experience of fourteen wastewater utilities. Results showed the effectiveness of the tools and methods at different stages of the AWARE-P methodology. [ABSTRACT FROM AUTHOR]

Interspaced repetitive DNA elements and segmental duplications have been extensively analyzed in fishes through physical chromosome mapping methods, providing a better comprehension of the structure and organization of the genome of this group. In order to contribute to this scenario, a sequence integration study of different classes of repetitive DNA with high resolution physical chromosome mapping was performed in Sorubim lima. Fluorescence in situ hybridization (FISH) and fiber-FISH with probes for 18S and 5S rRNA genes, TTAGGGn sequence and non-LTR retrotransposon family members Rex1, Rex3 and Rex6 showed that non-LTR elements may be dispersed in the chromosome set with relative concentration in heterochromatic regions, as shown by Rex1, or may even intercalate in 45S rDNA and the telomeric sequence, as found for Rex3 and Rex6. These results reinforce the presence of preferential regions of retroelement accumulation and contribute to a better understanding of the genomic organization of some repetitive DNA classes in fishes. © 2013 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

The Xyp sex determination mechanism is the system most frequent and ancestral to Coleoptera. Moreover, the presence of argyrophilous material associated with the sex bivalent is described as being responsible for the maintenance and association of these chromosomes. There are no karyotype data available regarding the genus Lagria and no consensus in the literature regarding the argyrophilous material present in the lumen of sex bivalent. Therefore, the aim of this work was to investigate the mechanism of sex chromosome bivalent association in Lagria villosa by analyzing the argyrophilous nature of the material present in the Xyp lumen. It was also intended to characterize L. villosa cytogenetically. The analysis of meiotic cells showed 2n = 18 = 16+Xyp for males and 2n = 18 = 16+XX in females and the meiotic formula was 2n = 8II+Xyp. The C-banding showed blocks of pericentromeric heterochromatin in all chromosomes except in the yp chromosome. In these regions, the use of fluorochromes revealed the presence of heterochromatin containing GC rich DNA sequences. The study of synaptonemal complex showed a gradual increase in the electron-density of the axial elements of the sex chromosomes and their association with strongly electron-dense material. The pepsin pretreatment revealed that the material impregnated by silver is protein. Copyright © 2012 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Thrips are small insects (0.5–3.0 mm) with distinct habits and life histories characterized by haplodiploid sex determination. In general, low levels of genetic diversity have been reported in haplodiploid insects, although most reports focus on the order Hymenoptera. Therefore, we used RAPD markers to evaluate the structure and both inter- and intra-population genetic variability of Gynaikothrips uzeli (Thysanoptera: Phlaeothripidae). Six populations, three from Paraná state, southern Brazil, and three from Bahia, northeastern Brazil, were studied. Similarly to other haplodiploid insects, the genetic diversity of G. uzeli was reduced. This result is putatively related to the haplodiploid sex determination system, which yields little genetic variation, and to ecological traits of the studied species, such as the low dispersal abilities and life mode in leaf galls. All individuals were homogeneously clustered in their respective collection sites, forming two main groups in which populations from similar environments were more closely related. The analyzed populations were highly structured, and the genetic variation was higher among than within populations. [ABSTRACT FROM PUBLISHER]

Neotropical fishes have a low rate of chromosome differentiation between sexes. The present study characterizes the first meiotic analysis of sex chromosomes in the order Gymnotiformes. Gymnotus pantanal - females had 40 chromosomes (14m/sm, 26st/a) and males had 39 chromosomes (15m/sm, 24st/a), with a fundamental number of 54 - showed a multiple sexual determination chromosome system of the type X1X1X2X2/X1X2Y. The heterochromatin is restricted to centromeres of all chromosomes of the karyotype. The meiotic behavior of sex chromosomes involved in this system in males is from a trivalent totally pared in the pachytene stage, with a high degree of similarity. The cells of metaphase II exhibit 19 and 20 chromosomes, normal disjunction of sex chromosomes and the formation of balanced gametes with 18 + Y and 18 + X1X2 chromosomes, respectively. The small amount of heterochromatin and repetitive DNA involved in this system and the high degree of chromosome similarity indicated a recent origin of the X1X1X2X2/X1X2Y system in G. pantanal and suggests the existence of a simple ancestral system with morphologically undifferentiated chromosomes. Copyright © 2011 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Physical mapping of 5S rDNA in 2 species of knifefishes, Gymnotuspantanal and G. paraguensis (Gymnotiformes), was performed using fluorescence in situ hybridization with a 5S rDNA probe. The 5S rDNA PCR product from the genomes of both species was also sequenced and aligned to determine non-transcribed spacer sequences (NTS). Both species under study had different patterns of 5S rDNA gene cluster distribution. While in the karyotype of G. pantanal two 5S rDNA-bearing pairs were observed, the karyotype of G. paraguensis possessed as many as 19 such pairs. Such multiplication of 5S rDNA gene clusters might be caused by the involvement of transposable elements because the NTS of G. paraguensis was 400 bp long with high identity (90%) with a mobile transposable element called Tc1-like transposon, described from the cyprinid fish Labeo rohita. Copyright © 2011 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Abstract: Power distribution utilities often use impedance-based methods for locating faults along their feeders. For feeders with laterals, these techniques may identify different possible locations for the same fault. This leads to higher costs and longer restoration time. In order to improve impedance-based methods, faulted-circuit indicators (FCI) can be allocated along the feeder to reduce, or even eliminate, the uncertainty about the fault location. This paper proposes a technique for optimally allocating a given number of FCIs along distribution feeders using the Chu–Beasley genetic algorithm to solve the optimization problem. The proposed objective functions measure the number of locations that are suspected to be the actual fault location or the distance among them. Additionally, it is possible to consider the presence of priority areas. We present results for the IEEE 34-bus system and for a 475-bus actual system. The results show the effectiveness of the proposed technique in improving impedance-based fault location methods. [ABSTRACT FROM AUTHOR]