A decomposition heuristic for the maximal covering location problem

This paper proposes a cluster partitioning technique to calculate improved upper bounds to the optimal solution of maximal covering location problems. Given a covering distance, a graph is built considering as vertices the potential facility locations, and with an edge connecting each pair of facilities that attend a same client. Coupling constraints, corresponding to some edges of this graph, are identified and relaxed in the Lagrangean way, resulting in disconnected subgraphs representing smaller subproblems that are computationally easier to solve by exact methods. The proposed technique is compared to the classical approach, using real data and instances from the available literature. © 2010 Edson Luiz França Senne et al.

Application of molecular markers on genetic improvement and reproduction in the post-genomic Era: Emerging biotechnologies and perspectives in livestock

Background: New challenges are rising in the animal protein market, and one of the main world challenges is to produce more in shorter time, with better quality and in a sustainable way. Brazil is the largest beef exporter in volume hence the factors affecting the beef meat chain are of major concern in countrýs economy. An emerging class of biotechnological approaches, the molecular markers, is bringing new perspectives to face these challenges, particularly after the publication of the first complete livestock genome (bovine), which has triggered a massive initiative to put in practice the benefits of the so called the Post-Genomic Era. Review: This article aimed at showing the directions and insights in the application of molecular markers on livestock genetic improvement and reproduction as well at organizing the progress so far, pointing some perspectives of these emerging technologies in Brazilian ruminant production context. An overview on the nature of the main molecular markers explored in ruminant production is provided, which describes the molecular bases and detection approaches available for microsatellites (STR) and single nucleotide polymorphisms (SNP). A topic is dedicated to review the history of association studies between markers and important trait variation in livestock, showing the timeline starting on quantitative trait loci (QTL) identification using STR markers and ending in high resolution SNP panels to proceed whole genome scans for phenotype/genotype association. Also the article organizes this information to reveal how QTL prospection using STR could open ground to the feasibility of marker-assisted selection and why this approach is quickly being replaced by studies involving the application of genome-wide association using SNP research in a new concept called genomic selection. Conclusion: The world's scientific community is dedicating effort and resources to apply SNP information in livestock selection through the development of high density panels for genomic association studies, connecting molecular genetic data with phenotypes of economic interest. Once generated, this information can be used to take decisions in genetic improvement programs by selecting animals with the assistance of molecular markers.

A importância das informações aferentes podais para o controle postural

Introduction. The postural control involves a complex mechanism for connecting the afferent and efferent pathways and their integration into the central nervous system (CNS). Three systems are responsible to obtain outside information: visual, vestibular and sensory. Recent studies have shown that among such systems, the CNS shows a greater predilection for sensory information to postural control. Objective. Given this, the review proposes to discuss the feet sensory information importance and its reflection in postural control mechanisms. Method. For this reason, a literature search was carried out by PubMed and Bireme libraries, and papers of the last five years were selected. Specific books were also used. Discussion. Studies were separated into topics on sensory information integration to neuro-motor answer, postural feed-forward adjustments recruitment mechanisms; neuro-muscular coordination and synergy responses and the musculoskeletal tissues role. Conclusion. Despite has been found a large number of studies, the real mechanism that the CNS uses to filter, integrate and process the sensory information and select the appropriate motor response, be it for the movement or posture for the stabilization remains obscure.

Involvement of the atrial natriuretic peptide in cardiovascular pathophysiology and its relationship with exercise

In this minireview we describe the involvement of the atrial natriuretic peptide (ANP) in cardiovascular pathophysiology and exercise. The ANP has a broad homeostatic role and exerts complex effects on the cardio-circulatory hemodynamics, it is produced by the left atrium and has a key role in regulating sodium and water balance in mammals and humans. The dominant stimulus for its release is atrial wall tension, commonly caused by exercise. The ANP is involved in the process of lipolysis through a cGMP signaling pathway and, as a consequence, reducing blood pressure by decreasing the sensitivity of vascular smooth muscle to the action of vasoconstrictors and regulate fluid balance. The increase of this hormone is associated with better survival in patients with chronic heart failure (CHF). This minireview provides new evidence based on recent studies related to the beneficial effects of exercise in patients with cardiovascular disease, focusing on the ANP. © 2012 de Almeida et al; licensee BioMed Central Ltd.

Morphological Variation of Primary Reproductive Structures in Males of Five Families of Neotropical Bats

Bats present unique features among mammals with respect to reproduction, and although neotropical bats do not have a hibernation period, many of their reproductive characteristics vary seasonally and interspecifically. Thus, this work aimed to examine the reproductive structures of 18 species belonging to five families of Brazilian bats. The gross anatomy of the testes varied little; however, the epididymis of Emballonuridae and Vespertilionidae showed exceptional structures with a large elongation of the caudal region. We observed a wide variation in the positioning of the testes: Phyllostomidae and Noctilionidae presented external testes; Emballonuridae and Molossidae presented migratory testes that may be in intra-abdominal or external positions; and Vespertilionidae displayed scrotal testes. In the histological evaluation, we observed a different pattern in vespertilionid species, with testicular regression and sperm retention/storage in the cauda epididymis in the five species analyzed. Similar testicular regression was observed in Molossops temminckii; however, sperm retention/storage was not observed in this species. These data suggest that although the species analyzed are tropical species that do not present a prolonged period of torpor (hibernation), they still maintain a period of seminiferous tubule regression and sperm storage very similar to that observed in hibernating bats. © 2012 Wiley Periodicals, Inc.

Intraspecific variation and emendation of Hannaella kunmingensis

In order to investigate the intraspecific variability in Hannaella kunmingensis, 11 isolates, including the type strain, were analyzed for their morphological and biochemical traits. The combined internal transcribed spacer region (ITS), D1/D2 domains of the large subunit rDNA (LSU), and cytochrome b gene were examined using phylogenetic and parsimony network analyses. Our investigations revealed differences in colony morphology as well as differences in 31 out of 64 phenotypic characteristics examined, including growth in lactose, vitamin free medium, xylitol, L-arabinitol, and nitrite. Growth in the presence of 0. 1 % cycloheximide was also highlighted in H. kunmingensis. All the 11 strains were conspecific in the LSU; however, variations of about 2. 5 % were found in the ITS while isolate CBS 8356 exhibited a 27. 3 % divergence from the other strains in the cytochrome b gene. Parsimony network analysis revealed the existence of three haplotypes among the H. kunmingensis strains studied but excluded CBS 8356 from the network connecting these haplotypes. This study contributes to the knowledge of the intraspecific diversity of H. kunmingensis. To accommodate such intraspecific variations, an emendation of the species diagnosis is proposed. © 2012 German Mycological Society and Springer.

Bothrops leucurus venom induces nephrotoxicity in the isolated perfused kidney and cultured renal tubular epithelia

Bites from snake (Bothrops genus) cause local tissue damage and systemic complications, which include alterations such as hemostatic system and acute renal failure (ARF). Recent studies suggest that ARF pathogenesis in snakebite envenomation is multifactorial and involves hemodynamic disturbances, immunologic reactions and direct nephrotoxicity. The aim of the work was to investigate the effects of the Bothrops leucurus venom (BlV) in the renal perfusion system and in cultured renal tubular cells of the type MDCK (Madin-Darby Canine kidney). BlV (10 μg/mL) reduced the perfusion pressure at 90 and 120 min. The renal vascular resistance (RVR) decreased at 120 min of perfusion. The effect on urinary flow (UF) and glomerular filtration rate (GFR) started 30 min after BlV infusion, was transient and returned to normal at 120 min of perfusion. It was also observed a decrease on percentual tubular transport of sodium (%TNa+) at 120 min and of chloride (%TCl-) at 60 and 90 min. The treatment with BlV caused decrease in cell viability to the lowest concentration tested with an IC50 of 1.25 μg/mL. Flow cytometry with annexin V and propidium iodide showed that cell death occurred predominantly by necrosis. However, a cell death process may involve apoptosis in lower concentrations. BlV treatment (1.25 μg/mL) led to significant depolarization of the mitochondrial membrane potential and, indeed, we found an increase in the expression of cell death genes in the lower concentrations tested. The venom also evoked an increase in the cytosolic Ca2+ in a concentration dependent manner, indicating that Ca2+ may participate in the venom of B. leucurus effect. The characterization of the effects in the isolated kidney and renal tubular cells gives strong evidences that the acute renal failure induced by this venom is a result of the direct nephrotoxicity which may involve the cell death mechanism. © 2012.

Immunoexpression of aromatase and estrogen receptors β in stem spermatogonia of bullfrogs indicates a role of estrogen in the seasonal spermatogonial mitotic activity

Bullfrog stem spermatogonia, also named primordial germ cells (PGCs), show strong testosterone immunolabeling in winter, but no or weak testosterone immunoexpression in summer. Thus, the role of testosterone in these cells needs to be clarified. In this study, we proposed to evaluate whether PGCs express aromatase and estrogen receptors, and verify a possible role of estrogen in PGCs seasonal proliferation. Testes of male adult bullfrogs, collected in winter (WG) and summer (SG), were fixed and embedded in historesin, for quantitative analysis, or paraffin for immunohistochemistry (IHC). The number of haematoxylin/eosin stained PGCs/lobular area was obtained. Proliferating cell nuclear antigen (PCNA), aromatase, estrogen receptor β (ERβ) and PCNA/ERβ double immunolabeling were detected by IHC. The number of PCNA-positive PGCs and the histological score (HSCORE) of aromatase and ERβ immunolabeled PGCs were obtained. Although the number of PGCs increased significantly in WG, a high number of PCNA-positive PGCs was observed in summer. Moreover, aromatase and ERβ HSCORE was higher in SG than WG. The results indicate that PGCs express a seasonal proliferative activity; the low mitotic activity in winter is related to the maximal limit of germ cells which can be supported in the large lobules. In SG, the increased ERβ and aromatase HSCORE suggests that testosterone is converted into estrogen from winter to summer. Moreover, the parallelism between the high PGCs mitotic activity and ERβ immunoexpression suggest a participation of estrogen in the control of the PGCs seasonal proliferative activity which guarantee the formation of new germ cysts from summer to next autumn. © 2012 Elsevier Inc.

Cellular responses in the Malpighian tubules of Scaptotrigona postica (Latreille, 1807) exposed to low doses of fipronil and boric acid

Studies of sub-lethal effects of pesticide residues on stingless bees are scarce and morphological analysis of organs would add information to toxicological analysis in order to clarify the continuous exposure of Scaptotrigona postica to insecticides. The aim of this study was to evaluate the morphology and histochemistry of the Malpighian tubules (excretory organ) of S. postica exposed to fipronil or boric acid to detect cellular responses that indicate toxicity or adaptative mechanisms to stress induced by exposure of worker bees to low doses of these chemical compounds. Newly emerged bees were submitted to toxicological bioassays and morphological analyses by optical microscopy and Transmission Electron Microscopy, as well as histochemical methods, were performed to detect proteins and glycoconjugates. Additionally, immunohistochemical detection of DNA fragmentation and HSP70 (70-kDa Heat shock protein) were performed to detect cell death and stress response, respectively. Statistical analysis, for the bioassays conducted with ingestion of contaminated diet with boric acid at 0.75% (w/w) or with fipronil at 0.1μg/kg of food, showed that the survival of bees that ingested the contaminated diets were significantly different to the survival rate presented by the control group (P<0.0001). Although some characteristics indicative of initiation of cell death were observed, the cells remained metabolically active in the processes of excretion and inactivation of chemical compounds. The data from this study reinforce the importance of research on sublethal effects of low doses of pesticides on bees in an attempt to assess a possible realistic dose and evaluate the risk assessment of stingless bee S. postica foraging in the vicinity of cultivated fields and/or in green urban areas. © 2013 Elsevier Ltd.

Mechanisms in the bed nucleus of the stria terminalis involved in control of autonomic and neuroendocrine functions: A review

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of sublethal doses of imidacloprid in malpighian tubules of africanized Apis mellifera (Hymenoptera, Apidae)

In Brazil, imidacloprid is a widely used insecticide on agriculture and can harm bees, which are important pollinators. The active ingredient imidacloprid has action on the nervous system of the insects. However, little has been studied about the actions of the insecticide on nontarget organs of insects, such as the Malpighian tubules that make up the excretory and osmoregulatory system. Hence, in this study, we evaluated the effects of chronic exposure to sublethal doses of imidacloprid in Malpighian tubules of Africanized Apis mellifera. In the tubules of treated bees, we found an increase in the number of cells with picnotic nuclei, the lost of part of the cell into the lumen, and a homogenization of coloring cytoplasm. Furthermore, we observed the presence of cytoplasmic vacuolization. We confirmed the increased occurrence of picnotic nuclei by using the Feulgan reaction, which showed the chromatin compaction was more intense in the tubules of bees exposed to the insecticide. We observed an intensification of the staining of the nucleus with Xylidine Ponceau, further verifying the cytoplasmic negative regions that may indicate autophagic activity. Additionally, immunocytochemistry experiments showed TUNEL positive nuclei in exposed bees, implicating increased cell apoptosis after chronic imidacloprid exposure. In conclusion, our results indicate that very low concentrations of imidacloprid lead to cytotoxic activity in the Malpighian tubules of exposed bees at all tested times for exposure and imply that this insecticide can alter honey bee physiology. © 2013 Wiley Periodicals, Inc.

Light microscope observations on the epididymis of paca (Agouti paca)

The features of paca epididymis, based on its appearance in light microscope, is described in this paper. The cellular population of the epithelial lining comprises principal cells, basal cells, apical cells, narrows cells, and hallo cells. The epididymis is divided in five distinct and continuous regions, Zone I, or initial segment, and zone II, are both localized into the head. Zone III comprises the distal head and all the body. Zones IV and V are restricted to the tail, in the proximal and distal cauda epididymis respectively. Each zone can be readily distinguished on the basis of morphological characteristics. The height of epididymal epithelium is greater in zone I. There is a progressive increase in the diameter of the tubular lumen through the different areas, with the maximum in the zone V. The presence of a high epithelium, and the virtual absence of sperm in zone I suggest fast transit of spermatozoa in this region. Zone V comprises the distal tail, has smaller epithelial lining, greater luminal diameter, shorter stereocilia than the other zones, and contains spermatozoa packed inside the lumen, that characterizes this zone as a place of sperm storage. The findings are compared with other reports in rodents and other domestic animals, to contribute to the understanding of epididymal morphophysiology. © 2013 Firenze University Press.

Photogrammetric refinement of laser-based building roof contours

In this paper a photogrammetric method is proposed for refining 3D building roof contours extracted from airborne laser scanning data. It is assumed that laser-derived planar faces of roofs are potentially accurate, while laser-derived building roof contours are not well defined. First, polygons representing building roof contours are extracted from a high-resolution aerial image. In the sequence, straight-line segments delimitating each building roof polygon are projected onto the corresponding laser-derived roof planes by using a new line-based photogrammetric model. Finally, refined 3D building roof contours are reconstructed by connecting every pair of photogrammetrically- projected adjacent straight lines. The obtained results showed that the proposed approach worked properly, meaning that the integration of image data and laser scanning data allows better results to be obtained, when compared to the results generated by using only laser scanning data. © 2013 IEEE.

Aspectos estruturais do hepatopâncreas do camarão de água doce Macrobracium amazonicum (Heller, 1862)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Aspectos morfológicos, ultra-estruturais e distribuição dos túbulos de Malpighi do diplópodo Urostreptus atrobrunneus Pierozzi & Fontanetti, 2006

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)