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Sample records for rhodnius prolixus stahl

  1. Acidocalcisomes as calcium- and polyphosphate-storage compartments during embryogenesis of the insect Rhodnius prolixus Stahl.

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    Isabela Ramos

    Full Text Available BACKGROUND: The yolk of insect eggs is a cellular domain specialized in the storage of reserve components for embryo development. The reserve macromolecules are stored in different organelles and their interactions with the embryo cells are mostly unknown. Acidocalcisomes are lysosome-related organelles characterized by their acidic nature, high electron density and large content of polyphosphate bound to several cations. In this work, we report the presence of acidocalcisome-like organelles in eggs of the insect vector Rhodnius prolixus. METHODOLOGY/PRINCIPAL FINDINGS: Characterization of the elemental composition of electron-dense vesicles by electron probe X-ray microanalysis revealed a composition similar to that previously described for acidocalcisomes. Following subcellular fractionation experiments, fractions enriched in acidocalcisomes were obtained and characterized. Immunofluorescence showed that polyphosphate polymers and the vacuolar proton translocating pyrophosphatase (V-H(+-PPase, considered as a marker for acidocalcisomes are found in the same vesicles and that these organelles are mainly localized in the egg cortex. Polyphosphate quantification showed that acidocalcisomes contain a significant amount of polyphosphate detected at day-0 eggs. Elemental analyses of the egg fractions showed that 24.5±0.65% of the egg calcium are also stored in such organelles. During embryogenesis, incubation of acidocalcisomes with acridine orange showed that these organelles are acidified at day-3 (coinciding with the period of yolk mobilization and polyphosphate quantification showed that the levels of polyphosphate tend to decrease during early embryogenesis, being approximately 30% lower at day-3 compared to day-0 eggs. CONCLUSIONS: We found that acidocalcisomes are present in the eggs and are the main storage compartments of polyphosphate and calcium in the egg yolk. As such components have been shown to be involved in a series of dynamic

  2. The ACBP gene family in Rhodnius prolixus

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    Majerowicz, David; Hannibal-Bach, Hans K; Castro, Rodolfo S C

    2016-01-01

    The acyl-CoA-binding proteins (ACBP) constitute a family of conserved proteins that bind acyl-CoA with high affinity and protect it from hydrolysis. Thus, ACBPs may have essential roles in basal cellular lipid metabolism. The genome of the insect Rhodnius prolixus encodes five ACBP genes similar...

  3. Metabolism and gas exchange patterns in Rhodnius prolixus.

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    Schilman, Pablo E

    Insect's metabolic rate and patterns of gas-exchange varies according to different factors such as: species, activity, mass, and temperature among others. One particular striking pattern of gas-exchange in insects is discontinuous gas-exchange cycles, for which many different hypotheses regarding their evolution have been stated. This article does not pretend to be an extensive review on the subject, rather to focus on the work performed on the haematophagous bug Rhodnius prolixus, a model organism used from the mid XX century until present days, with the great influence of Wigglesworth and his students/collaborator's work. I have no doubt that the renovated field of insect gas-exchange has a bright future and will advance at large gaits thank to the help of this model organism, R. prolixus, whose entire genome has recently being unraveled. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Effects of azadirachtin in Rhodnius prolixus: data and hypotheses

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    E. S. Garcia

    1991-01-01

    Full Text Available The effects of azadirachtin A, a tetranortriterpenoid from the neem tree Azadirachta indica J., on both development and interaction between Trypanosoma cruzi, the causative agent of Chagas' disease, and its vector Rhodnius prolixus were studied. Given through a blood meal, a dose-rsponse relationship of azadirachtin was established using antifeedant effect and ecdysis inhibition as effective parameters. A singlo dose of azadirachtin A was able to block the onset of mitosis in the epidermis and ecdysteroid titers in the hemnolymph, determined by radioimmuneassay, were too low for an induction of ecadysis. The survival of T. cruzi was also studied in R. prolixus treated with the drug. If the trypomastigotes were fed in presence of azadirachtin A the number of parasites drastically decreased. If the drug was applied after infection of the bug with T. cruzi, the parasite was still abolished from the gut. If the insect was pretreated with azadirachtin A before infection the same observation was obtained. A single dose of azadirachtin A was enough for a permanent resistance of the insect host against its reinfection with T. cruzi and for blocking the ecdysis for a long time. The effects of azadirachtin A on the hormonal balance of the host and growth inhibition of the parasite will be discussed on the basis of the present results.

  5. Unsaturated Glycerophospholipids Mediate Heme Crystallization: Biological Implications for Hemozoin Formation in the Kissing Bug Rhodnius prolixus

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    Stiebler, R.; Majerowicz, David; Knudsen, Jens

    2014-01-01

    Hemozoin (Hz) is a heme crystal produced by some blood-feeding organisms, as an efficient way to detoxify heme derived from hemoglobin digestion. In the triatomine insect Rhodnius prolixus, Hz is essentially produced by midgut extracellular phospholipid membranes known as perimicrovillar membrane...

  6. Glycogen Synthase Kinase-3 is involved in glycogen metabolism control and embryogenesis of Rhodnius prolixus.

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    Mury, Flávia B; Lugon, Magda D; DA Fonseca, Rodrigo Nunes; Silva, Jose R; Berni, Mateus; Araujo, Helena M; Fontenele, Marcio Ribeiro; Abreu, Leonardo Araujo DE; Dansa, Marílvia; Braz, Glória; Masuda, Hatisaburo; Logullo, Carlos

    2016-10-01

    Rhodnius prolixus is a blood-feeding insect that transmits Trypanosoma cruzi and Trypanosoma rangeli to vertebrate hosts. Rhodnius prolixus is also a classical model in insect physiology, and the recent availability of R. prolixus genome has opened new avenues on triatomine research. Glycogen synthase kinase 3 (GSK-3) is classically described as a key enzyme involved in glycogen metabolism, also acting as a downstream component of the Wnt pathway during embryogenesis. GSK-3 has been shown to be highly conserved among several organisms, mainly in the catalytic domain region. Meanwhile, the role of GSK-3 during R. prolixus embryogenesis or glycogen metabolism has not been investigated. Here we show that chemical inhibition of GSK-3 by alsterpaullone, an ATP-competitive inhibitor of GSK3, does not affect adult survival rate, though it alters oviposition and egg hatching. Specific GSK-3 gene silencing by dsRNA injection in adult females showed a similar phenotype. Furthermore, bright field and 4'-6-diamidino-2-phenylindole (DAPI) staining analysis revealed that ovaries and eggs from dsGSK-3 injected females exhibited specific morphological defects. We also demonstrate that glycogen content was inversely related to activity and transcription levels of GSK-3 during embryogenesis. Lastly, after GSK-3 knockdown, we observed changes in the expression of the Wingless (Wnt) downstream target β-catenin as well as in members of other pathways such as the receptor Notch. Taken together, our results show that GSK-3 regulation is essential for R. prolixus oogenesis and embryogenesis.

  7. Effects of precocene and azadirachtin in Rhodnius prolixus: some data on development and reproduction

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    Eloi S. Garcia

    1987-01-01

    Full Text Available The results presented in this paper clearly indicate that precocene and azadirachtin are effective inhibitors of moulting and reproduction in the hemipteran Rhodnius prolixus. The time of application is important and only applications of these substances early in the intermoulting period cause their effects in nymphs. The inhibition of moulting is fully reversed by ecdysone therapy. Precocene and azadirachtin also affected drastically the oogenesis and egg deposition in this insect. Precocene-induced sterilization is reversed by application of juvenile hormone III. However, this hormone is unable to reverse the effect of azadirachtin on reproduction. Ecdysteroid titers in nymphs and adult females are decreased by these treatments. In vitro analysis suggest that precocene and azadirachtin may act directly on the prothoracic glands and ovaries producing ecdysteroids. Based on these and other findings the possible mode of action of these compounds on the development and reproduction of Rhodnius prolixus is discussed.

  8. Experimental Infection of Rhodnius prolixus (Hemiptera, Triatominae with Mycobacterium leprae Indicates Potential for Leprosy Transmission.

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    Arthur da Silva Neumann

    Full Text Available Leprosy is a chronic dermato-neurological disease caused by infection with Mycobacterium leprae. In 2013 almost 200,000 new cases of leprosy were detected around the world. Since the first symptoms take from years to decades to appear, the total number of asymptomatic patients is impossible to predict. Although leprosy is one of the oldest records of human disease, the mechanisms involved with its transmission and epidemiology are still not completely understood. In the present work, we experimentally investigated the hypothesis that the mosquitoes Aedes aegypti and Culex quinquefasciatus and the hemiptera Rhodnius prolixus act as leprosy vectors. By means of real-time PCR quantification of M. leprae 16SrRNA, we found that M. leprae remained viable inside the digestive tract of Rhodnius prolixus for 20 days after oral infection. In contrast, in the gut of both mosquito species tested, we were not able to detect M. leprae RNA after a similar period of time. Inside the kissing bug Rhodnius prolixus digestive tract, M. leprae was initially restricted to the anterior midgut, but gradually moved towards the hindgut, in a time course reminiscent of the life cycle of Trypanosoma cruzi, a well-known pathogen transmitted by this insect. The maintenance of M. leprae infectivity inside the digestive tract of this kissing bug is further supported by successful mice footpad inoculation with feces collected 20 days after infection. We conclude that Rhodnius prolixus defecate infective M. leprae, justifying the evaluation of the presence of M. leprae among sylvatic and domestic kissing bugs in countries endemic for leprosy.

  9. Experimental Infection of Rhodnius prolixus (Hemiptera, Triatominae) with Mycobacterium leprae Indicates Potential for Leprosy Transmission.

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    Neumann, Arthur da Silva; Dias, Felipe de Almeida; Ferreira, Jéssica da Silva; Fontes, Amanda Nogueira Brum; Rosa, Patricia Sammarco; Macedo, Rafael Enrique; Oliveira, José Henrique; Teixeira, Raquel Lima de Figueiredo; Pessolani, Maria Cristina Vidal; Moraes, Milton Ozório; Suffys, Philip Noel; Oliveira, Pedro L; Sorgine, Marcos Henrique Ferreira; Lara, Flavio Alves

    2016-01-01

    Leprosy is a chronic dermato-neurological disease caused by infection with Mycobacterium leprae. In 2013 almost 200,000 new cases of leprosy were detected around the world. Since the first symptoms take from years to decades to appear, the total number of asymptomatic patients is impossible to predict. Although leprosy is one of the oldest records of human disease, the mechanisms involved with its transmission and epidemiology are still not completely understood. In the present work, we experimentally investigated the hypothesis that the mosquitoes Aedes aegypti and Culex quinquefasciatus and the hemiptera Rhodnius prolixus act as leprosy vectors. By means of real-time PCR quantification of M. leprae 16SrRNA, we found that M. leprae remained viable inside the digestive tract of Rhodnius prolixus for 20 days after oral infection. In contrast, in the gut of both mosquito species tested, we were not able to detect M. leprae RNA after a similar period of time. Inside the kissing bug Rhodnius prolixus digestive tract, M. leprae was initially restricted to the anterior midgut, but gradually moved towards the hindgut, in a time course reminiscent of the life cycle of Trypanosoma cruzi, a well-known pathogen transmitted by this insect. The maintenance of M. leprae infectivity inside the digestive tract of this kissing bug is further supported by successful mice footpad inoculation with feces collected 20 days after infection. We conclude that Rhodnius prolixus defecate infective M. leprae, justifying the evaluation of the presence of M. leprae among sylvatic and domestic kissing bugs in countries endemic for leprosy.

  10. Analysis of antenal sensilla patterns of Rhodnius prolixus from Colombia and Venezuela

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    Lyda Esteban

    2005-12-01

    Full Text Available Antennal sensilla patterns were used to analyze population variation of domestic Rhodnius prolixus from six departments and states representing three biogeographical regions of Colombia and Venezuela. Discriminant analysis of the patterns of mechanoreceptors and of three types of chemoreceptors on the pedicel and flagellar segments showed clear differentiation between R. prolixus populations east and west of the Andean Cordillera. The distribution of thick and thin-walled trichoids on the second flagellar segment also showed correlation with latitude, but this was not seen in the patterns of other sensilla. The results of the sensilla patterns appear to be reflecting biogeographic features or population isolation rather than characters associated with different habitats and lend support to the idea that domestic R. prolixus originated in the eastern region of the Andes.

  11. Phase contrast X-ray synchrotron imaging for assessing external and internal morphology of Rhodnius prolixus

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    Almeida, Andre P. de, E-mail: apalmeid@gmail.com [Physics Institute, State University of Rio de Janeiro (Brazil); Nuclear Engineering Program, COPPE, Federal University of Rio de Janeiro (Brazil); Soares, Jose [Physics Institute, State University of Rio de Janeiro (Brazil); Meneses, Anderson A.M. [Radiological Sciences Laboratory, State University of Rio de Janeiro (Brazil); Federal University of Western Para (Brazil); Cardoso, Simone C. [Physics Institute, Federal University of Rio de Janeiro (Brazil); Braz, Delson [Nuclear Engineering Program, COPPE, Federal University of Rio de Janeiro (Brazil); Garcia, Eloi S. [Laboratory of Biochemistry and Physiology of Insects, Oswaldo Cruz Institute, FIOCRUZ (Brazil); Gonzalez, Marcelo S. [Department of General Biology, Federal University Fluminense (Brazil); Azambuja, Patricia [Laboratory of Biochemistry and Physiology of Insects, Oswaldo Cruz Institute, FIOCRUZ (Brazil); Barroso, Regina C. [Physics Institute, State University of Rio de Janeiro (Brazil)

    2012-07-15

    PhC-SR-{mu}CT is a nondestructive technique that allows the microanatomical investigations and 3D images reconstructions. This technique is performed in blood sucker, Rhodnius prolixus-one of the most important insect vectors of Trypanosoma cruzi, ethiologic agent of Chagas' disease in Latin America-was able to provide excellent information about the microanatomy of the thorax and head allowing a new tool for further studies of development and physiology of triatomine by a non-invasive method of observation. - Highlights: Black-Right-Pointing-Pointer In this work we used SR-PhC-{mu}CT to study the microanatomy of R. prolixus. Black-Right-Pointing-Pointer We investigate SR-PhC-{mu}CT to the 3D reconstruction of internal structures. Black-Right-Pointing-Pointer We get information about the tissues responsible for the development of the insect.

  12. Mariner transposons are sailing in the genome of the blood-sucking bug Rhodnius prolixus.

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    Filée, Jonathan; Rouault, Jacques-Deric; Harry, Myriam; Hua-Van, Aurélie

    2015-12-15

    The Triatomine bug Rhodnius prolixus is a vector of Trypanosoma cruzi, which causes the Chagas disease in Latin America. R. prolixus can also transfer transposable elements horizontally across a wide range of species. We have taken advantage of the availability of the 700 Mbp complete genome sequence of R. prolixus to study the dynamics of invasion and persistence of transposable elements in this species. Using both library-based and de novo methods of transposon detection, we found less than 6 % of transposable elements in the R. prolixus genome, a relatively low percentage compared to other insect genomes with a similar genome size. DNA transposons are surprisingly abundant and elements belonging to the mariner family are by far the most preponderant components of the mobile part of this genome with 11,015 mariner transposons that could be clustered in 89 groups (75 % of the mobilome). Our analysis allowed the detection of a new mariner clade in the R. prolixus genome, that we called nosferatis. We demonstrated that a large diversity of mariner elements invaded the genome and expanded successfully over time via three main processes. (i) several families experienced recent and massive expansion, for example an explosive burst of a single mariner family led to the generation of more than 8000 copies. These recent expansion events explain the unusual prevalence of mariner transposons in the R. prolixus genome. Other families expanded via older bursts of transposition demonstrating the long lasting permissibility of mariner transposons in the R. prolixus genome. (ii) Many non-autonomous families generated by internal deletions were also identified. Interestingly, two non autonomous families were generated by atypical recombinations (5' part replacement with 3' part). (iii) at least 10 cases of horizontal transfers were found, supporting the idea that host/vector relationships played a pivotal role in the transmission and subsequent persistence of transposable

  13. Perimicrovillar membrane assembly: the fate of phospholipids synthesised by the midgut of Rhodnius prolixus

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    Paula Rego Bittencourt-Cunha

    2013-06-01

    Full Text Available In this study, we describe the fate of fatty acids that are incorporated from the lumen by the posterior midgut epithelium of Rhodnius prolixus and the biosynthesis of lipids. We also demonstrate that neutral lipids (NL are transferred to the haemolymphatic lipophorin (Lp and that phospholipids remain in the tissue in which they are organised into perimicrovillar membranes (PMMs. 3H-palmitic acid added at the luminal side of isolated midguts of R. prolixus females was readily absorbed and was used to synthesise phospholipids (80% and NL (20%. The highest incorporation of 3H-palmitic acid was on the first day after a blood meal. The amounts of diacylglycerol (DG and triacylglycerol synthesised by the tissue decreased in the presence of Lp in the incubation medium. The metabolic fates of 3H-lipids synthesised by the posterior midgut were followed and it was observed that DG was the major lipid released to Lp particles. However, the majority of phospholipids were not transferred to Lp, but remained in the tissue. The phospholipids that were synthesised and accumulated in the posterior midgut were found to be associated with Rhodnius luminal contents as structural components of PMMs.

  14. Effects of azadirachtin on Rhodnius prolixus: immunity and trypanosoma interaction

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    Patricia de Azambuja

    1992-01-01

    Full Text Available The effects of azadirachtin, a tetranortriterpenoid from the neem tree Aradirachta indica J. on both immunity and Trypanosoma cruzi interaction within Rhodniusprolixus and other triatomines, were presented Given through a blood meal, azadirachtin affected the immune reactivity as shown by a significant reduction in numbers of hemocytes and consequently nodule formation follwing challenge with Enterobacter cloacae ß12, reduction in ability to produce antibacterial activities in the hemolymph when injected with bacteria, and decreased ability to destroy the infection caused by inoculation of E. cloacae cells. A single dose of azadirachtin was able to block the development of T. cruzi in R. prolixus if given through the meal at different intervals, together with, before or after parasite infection. Similary, these results were observed with different triatomine species and different strains of T. cruzi. Azadirachtin induced a permanent resistance of the vector against reinfection with T. cruzi. The significance of these data is discussed in relation to the general mode of azadirachtin action in insects.

  15. The proctolin gene and biological effects of proctolin in the blood-feeding bug, Rhodnius prolixus.

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    Ian eOrchard

    2011-10-01

    Full Text Available We have reinvestigated the possible presence or absence of the pentapeptide proctolin in Rhodnius prolixus and report here the cloning of the proctolin cDNA. The transcript is highly expressed in the central nervous system (CNS with some low expression associated with peripheral tissues. The proctolin prepropeptide encodes a single copy of proctolin along with a proctolin-precursor-associated peptide. We have biochemically identified proctolin in CNS extracts and shown its distribution using proctolin-like immunoreactivity. Immunostained processes are found on the salivary glands, female and male reproductive organs, and heart and associated alary muscles. Proctolin-like immunoreactive bipolar neurons are found on the lateral margins of the common oviduct and bursa. Proctolin is biologically active on R. prolixus tissues, stimulating increases in contraction of anterior midgut and hindgut muscles, and increasing heartbeat frequency. Contrary to the previous suggestion that proctolin is absent from R. prolixus, proctolin is indeed present and biologically active in this medically-important bug.

  16. Activity and Residual Effect of Two Formulations of Lambdacyhalothrin Sprayed on Palm Leaves to Rhodnius prolixus

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    Mazariego-Arana Miguel Angel

    2002-01-01

    Full Text Available The insecticidal activity and residual effect of two formulations of lambdacyhalothrin were evaluated with Rhodnius prolixus;laboratory and field tests were conducted in the State of Chiapas, Mexico. The results indicate that the lethal concentrations of the active ingredient of SC (LC50 = 2.37 and LC90 = 8.5 mg, a.i./m² were 4-8 times than those with the insecticide WP applied on R. prolixus bugs in palm leaves, a common building material for thatched roofs. Other investigators in South America recommended applying 30 mg a.i./m² in porous materials; we obtained that the products WP and SC were 3.5 and 16 times more effective on palm leaves. Regarding the evaluation of the residual effects in field spraying, there was up to 15 months persistence after the application of WP in two doses (8.6 mg a.i./m² and 3.752 mg a.i./m² with SC. We consider R. prolixus highly susceptible to the employed pyrethroids; they could be used to control this vector in the state of Chiapas, Mexico.

  17. Mecanismo antidiurético en Rhodnius Prolixus (Stal, 1859 (Hemiptera, Reduviidae

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    Ivonne Gómez

    1986-12-01

    Full Text Available Se propone para R. prolixus un mecanismo antidiurético, cuya actividad se pone de manifiesto una vez transcurrido el periodo diurético y se mantiene hasta que el insecto es alimentado nuevamente. Presumiblemente este mecanismo actua a nivel del esfinter rectal proximal y es inhibido por la ingesta, distención mecanica del buche y desinhibición central por decapitación. Se sugiere que la actividad antidiurética es mantenida por vía nerviosa y se modifica cuando hay distensión del buche o canudo es interrumpida la senãl nerviosa por decapitación. Se pone de manifiesto que la excreción de orina en R. prolixus no es controlada exclusivamente por la hormona diurética, sino que factores no ligados a la hemolinfa mantienen en estado diurético y no diurético a los insectos.An antidiuretic mechanism is proposed for Rhodnius prolixus, whose activity is manifested when the diuretic phase has terminated and is maintained until the insect has fed again. Presumably this mechanism acts at the level of the proximal rectal sphincter and is inhibited by ingestion, mechanical distension of the gut and central desinhibition by decapitation. It is suggested that the antidiuretic activity is maintained by the nervous system and is modified when there is distention of the gut or when the nervous signal is interrupted by decapitacion. It is demonstrated that the excretion of urine in R. prolixus is not controlled exclusively by the diuretic hormone, but rather that factors not linked to the haemolvmph maintain the insects in a diuretic or nondiuretic state.

  18. Rhodnius prolixus supergene families of enzymes potentially associated with insecticide resistance.

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    Schama, Renata; Pedrini, Nicolás; Juárez, M Patricia; Nelson, David R; Torres, André Q; Valle, Denise; Mesquita, Rafael D

    2016-02-01

    Chagas disease or American trypanosomiasis, is a potentially life-threatening illness caused by the protozoan parasite, Trypanosoma cruzi. Once known as an endemic health problem of poor rural populations in Latin American countries, it has now spread worldwide. The parasite is transmitted by triatomine bugs, of which Rhodnius prolixus (Hemiptera, Reduviidae, Triatominae) is one of the vectors and a model organism. This species occurs mainly in Central and South American countries where the disease is endemic. Disease prevention focuses on vector control programs that, in general, rely intensely on insecticide use. However, the massive use of chemical insecticides can lead to resistance. One of the major mechanisms is known as metabolic resistance that is associated with an increase in the expression or activity of detoxification genes. Three of the enzyme families that are involved in this process - carboxylesterases (CCE), glutathione s-transferases (GST) and cytochrome P450s (CYP) - are analyzed in the R. prolixus genome. A similar set of detoxification genes to those of the Hemipteran Acyrthosiphon pisum but smaller than in most dipteran species was found in R. prolixus genome. All major CCE classes (43 genes found) are present but the pheromone/hormone processing class had fewer genes than usual. One main expansion was detected on the detoxification/dietary class. The phosphotriesterase family, recently associated with insecticide resistance, was also represented with one gene. One microsomal GST gene was found and the cytosolic GST gene count (14 genes) is extremely low when compared to the other hemipteran species with sequenced genomes. However, this is similar to Apis mellifera, a species known for its deficit in detoxification genes. In R. prolixus 88 CYP genes were found, with representatives in the four clans (CYP2, CYP3, CYP4 and mitochondrial) usually found in insects. R. prolixus seems to have smaller species-specific expansions of CYP genes than

  19. Changes associated with laboratory rearing in antennal sensilla patterns of Triatoma infestans, Rhodnius prolixus, and Rhodnius pallescens (Hemiptera, Reduviidae, Triatominae

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    Catalá SS

    2004-01-01

    Full Text Available We examined changes in the array of antennal sensilla of three species of Triatominae (Triatoma infestans, Rhodnius prolixus, and R. pallescens following their establishment for different periods in laboratory culture. In each case, the laboratory colonies were compared with conspecific samples taken directly from the field, by quantitative analysis of the sensilla arrays on the three distal segments of the antenna in terms of the densities of three types of chemoreceptors (basiconics and thick and thin walled trichoids and one type of mechanoreceptor (bristles. Sensilla densities were compared by ANOVA or non-parametric tests, and by multivariate discriminant analysis. Strains of the same species reared in different laboratories showed significant differences in their sensilla arrays, especially when compared to field-collected material from the same geographic origin. A Bolivian strain of T. infestans reared in the laboratory for 15 years and fed at monthly intervals, showed greatest differences from its conspecific wild forms, especially in terms of reductions in the number of chemoreceptors. By contrast, an Argentine strain of T. infestans reared for 25 years in the laboratory and fed weekly, showed a relative increase in the density of mechanoreceptors. A Colombian strain of R. prolixus reared for 20 years and fed weekly or fortnightly, showed only modest differences in the sensilla array when compared to its wild populations from the same area. However, a Colombian strain of R. pallescens reared for 12 years and fed fortnightly, did show highly significant reductions in one form of chemoreceptor compared to its conspecific wild populations. For all populations, multivariate analysis clearly discriminated between laboratory and field collected specimens, suggesting that artificial rearing can lead to modifications in the sensory array. This not only supports the idea of morphological plasticity in these species, but also suggests caution in

  20. Effects of juvenile hormone analogue on ecdysis prevention induced by precocene in Rhodnius prolixus (Hemiptera: Reduviidae

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    Patricia de Azambuja

    1984-12-01

    Full Text Available Precocene II, added to the meal of fourth-instar larvae of Rhodnius prolixus (25 mug/ml of blood, induced an in crease in the duration of the molting cycle. This effect was related to the decrease of both the nuclear area of the prothoracic gland cells and the mitotic activity in epidermal cellS. juvenile hormone analogue applied topically (60 mug/insect together with Precocene II treatment avoided atrophy of the prothoracic glands and induced a higher number of epidermal mitosis accelerating the time of subsequent ecdysis. A possible relationship between juvenile hormone and production of ecdysone is discussed.Adicionado ao sangue alimentar na dose de 25 mug/ml o precoceno II causou um aumento no período de intermuda em ninfas de 4o. estadio de Rhodnius prolixus. Este atraso da muda foi relacionado com a diminuição da área dos núcleos das celulas das glandulas protoracicas e com a queda da atividade mitotica das células da epiderme do inseto. Um análogo de hormônio juvenil aplicado topicamente (60 mug/inseto junto com o tratamento oral com precoceno II preveniu a atrofia das glândulas protorácicas e induziu um aumento no número de mitoses nas células da epiderme, diminuindo o período de intermuda nestes insetos.A possivel relação entre a ação do hormônio juvenil e a producao de ecdisona pelas glândulas protorácicas e discutida.

  1. Unsaturated glycerophospholipids mediate heme crystallization: biological implications for hemozoin formation in the kissing bug Rhodnius prolixus.

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    Renata Stiebler

    Full Text Available Hemozoin (Hz is a heme crystal produced by some blood-feeding organisms, as an efficient way to detoxify heme derived from hemoglobin digestion. In the triatomine insect Rhodnius prolixus, Hz is essentially produced by midgut extracellular phospholipid membranes known as perimicrovillar membranes (PMVM. Here, we investigated the role of commercial glycerophospholipids containing serine, choline and ethanolamine as headgroups and R. prolixus midgut lipids (RML in heme crystallization. All commercial unsaturated forms of phospholipids, as well as RML, mediated fast and efficient β-hematin formation by means of two kinetically distinct mechanisms: an early and fast component, followed by a late and slow one. The fastest reactions observed were induced by unsaturated forms of phosphatidylethanolamine (uPE and phosphatidylcholine (uPC, with half-lives of 0.04 and 0.7 minutes, respectively. β-hematin crystal morphologies were strikingly distinct among groups, with uPE producing homogeneous regular brick-shaped crystals. Interestingly, uPC-mediated reactions resulted in two morphologically distinct crystal populations: one less representative group of regular crystals, resembling those induced by uPE, and the other largely represented by crystals with numerous sharp edges and tapered ends. Heme crystallization reactions induced by RML were efficient, with a heme to β-hematin conversion rate higher than 70%, but clearly slower (t1/2 of 9.9-17.7 minutes than those induced by uPC and uPE. Interestingly, crystals produced by RML were homogeneous in shape and quite similar to those mediated by uPE. Thus, β-hematin formation can be rapidly and efficiently induced by unsaturated glycerophospholipids, particularly uPE and uPC, and may play a role on biological heme crystallization in R. prolixus midgut.

  2. Comparative Analysis of Repetitive DNA between the Main Vectors of Chagas Disease: Triatoma infestans and Rhodnius prolixus.

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    Pita, Sebastián; Mora, Pablo; Vela, Jesús; Palomeque, Teresa; Sánchez, Antonio; Panzera, Francisco; Lorite, Pedro

    2018-04-24

    Chagas disease or American trypanosomiasis affects six to seven million people worldwide, mostly in Latin America. This disease is transmitted by hematophagous insects known as "kissing bugs" (Hemiptera, Triatominae), with Triatoma infestans and Rhodnius prolixus being the two most important vector species. Despite the fact that both species present the same diploid chromosome number (2 n = 22), they have remarkable differences in their total DNA content, chromosome structure and genome organization. Variations in the DNA genome size are expected to be due to differences in the amount of repetitive DNA sequences. The T. infestans genome-wide analysis revealed the existence of 42 satellite DNA families. BLAST searches of these sequences against the R. prolixus genome assembly revealed that only four of these satellite DNA families are shared between both species, suggesting a great differentiation between the Triatoma and Rhodnius genomes. Fluorescence in situ hybridization (FISH) location of these repetitive DNAs in both species showed that they are dispersed on the euchromatic regions of all autosomes and the X chromosome. Regarding the Y chromosome, these common satellite DNAs are absent in T. infestans but they are present in the R. prolixus Y chromosome. These results support a different origin and/or evolution in the Y chromosome of both species.

  3. Trypanosoma cruzi: effects of azadirachtin and ecdysone on the dynamic development in Rhodnius prolixus larvae.

    Science.gov (United States)

    Cortez, M R; Provençano, A; Silva, C E; Mello, C B; Zimmermann, L T; Schaub, G A; Garcia, E S; Azambuja, P; Gonzalez, M S

    2012-07-01

    The effects of azadirachtin and ecdysone on the Trypanosoma cruzi population in the Rhodnius prolixus gut were investigated. T. cruzi were rarely found in the gut compartments of azadirachtin-treated larvae. High parasite numbers were observed in the stomach of the control and ecdysone groups until 10 days after treatment and in the small intestine and rectum until 25 days after treatment. High percentages of round forms developed in the stomachs of all groups, whereas azadirachtin blocked the development of protozoan intermediate forms. This effect was counteracted by ecdysone therapy. In the small intestine and rectum, epimastigotes predominated for all groups, but more of their intermediates developed in the control and ecdysone groups. Azadirachtin supported the development of round forms and their intermediates into trypomastigotes. In the rectum, trypomastigotes did not develop in the azadirachtin group and developed much later after ecdysone therapy. The parallel between the effects of azadirachtin and ecdysone on the host and parasite development is discussed on the basis of the present results because ecdysone appears to act directly or indirectly in determining the synchronic development of T. cruzi forms from round to epimastigotes, but not metacyclic trypomastigotes, in the invertebrate vector. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. A resposta de Rhodnius prolixus a estímulos térmicos

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    Terezinha Fujita

    1976-06-01

    Full Text Available Uma série de experiências com formas adultas de Rhodnius prolixus, realizadas tanto no laboratório como em recinto de dimensões mais amplas, demonstrou uma acentuada atração para fontes de calor, com um máximo de atividades em torno dos 37 graus Centígrados. Nossos estudos revelaram que o inseto percebe estímulos térmicos a uma certa distância da fonte. Embora o reconhecimento de radiações infra-vermelhas possa servir para uma orientação do triatomíneo em direção ao animal de sangue quente, não acreditamos que seja o único fator envolvido. Com a continuação de pesquisas deste gênero visa-se o aperfeiçoamento de uma técnica que se preste para o combate ao vetor.

  5. Functional anatomy of vagina muscles in the blood-feeding insect, Rhodnius prolixus.

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    Chiang, R G; O'Donnell, M J

    2009-11-01

    The physiology of the muscles associated with the vagina in the blood-feeding insect, Rhodnius prolixus Stal, was investigated with the use of Methylene Blue staining to visualize the anatomy, and a micro force transducer to record spontaneous and neurally-evoked contractions. The vagina is associated with a dorsal muscle and a set of paired lateral muscles. The dorsal muscle extends from the base of the common oviduct to apodemes located laterally on sternite VIII, the first genital segment. The lateral muscles extend from a medially-located apodeme on the posterior edge of sternite VI around each side of the common oviduct to travel posteriorly along the side of the vagina before inserting laterally on apodemes on sternite VIII. The vagina muscles display spontaneous and neurally-evoked contractions that are prolonged but transient. The response to evoked contractions shows that the muscles are innervated by both excitatory and inhibitory motor axons. The degree of tension generated by evoked contractions is dependent on the frequency of stimulation with maximal tension being generated at 20-30Hz. This tension, which often exceeds 400mg, is transient and returns to a baseline within 1 to 2min during continuous stimulation. These results, which are the first to describe this chamber in this well-studied insect, are discussed with respect to the act of egg laying.

  6. Effects of the essential oil obtained from Pilocarpus spicatus Saint-Hilaire (Rutaceae on the development of Rhodnius prolixus nymphae

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    Cícero B. Mello

    Full Text Available Bioassays against fifth-instar nymphae of Rhodnius prolixus were conducted with essential oil of Pilocarpus spicatus extracted by hydrodistillation. The main results may be summarized as follows: (i high levels of toxicity and paralysis together with discrete moulting inhibition were caused by topical application of either 0.5 µL or 1.0 µL per insect of the crude essential oil; (ii partial fagoinhibition, high moulting inhibition, prolonged intermoulting period and high number of paralyzed insects, but no toxicity were observed after oral treatment using either 5 µL or 10 µL of Pilocarpus spilcatus essential oil per mL of ingested blood meal. The importance of these results in relation to the relevant biological events in R. prolixus is herein discussed.

  7. Environmental variables, remote sensing and geographical information systems applied to the study of Rhodnius prolixus distribution in Colombia

    International Nuclear Information System (INIS)

    Guhl, Felipe

    2010-01-01

    A data base of the entomological survey performer during the Chagas Disease National Control Programme (CHDNCP) in 1997 - 2001 and temporal satellite images masp containing 57 environmental variables were used to build Rhodnius prolixus dispersion predictive maps in Colombia, based on temporal images, Fourier analyses and a discriminative multivaried statistical analyses of the variables studied. The maps show the dispersion of this species and its implication on the Chagas disease transmission in Colombia. A clear division in the predictive dispersion of R. prolixus in two geographical zones was found: one area in the southeast of the Eastern Cordillera associated with the environmental variables used in the present study and a second zone in the Andean Valleys, East of the Eastern Cordillera not much defined by the same variables. This would suggest that the Southwest Region. of Colombia presents a tendency to a wider dispersion of R. prolixus associated to other variables like human intervention. Sylvatic populations of R. prolixus were found recently in Attalea butyracea palm trees in this Region of the Eastern Planes demonstrating the prediction of the presence of this species.

  8. Modeling horizontal gene transfer (HGT in the gut of the Chagas disease vector Rhodnius prolixus

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    Durvasula Ravi V

    2011-05-01

    Full Text Available Abstract Background Paratransgenesis is an approach to reducing arthropod vector competence using genetically modified symbionts. When applied to control of Chagas disease, the symbiont bacterium Rhodococcus rhodnii, resident in the gut lumen of the triatomine vector Rhodnius prolixus (Hemiptera: Reduviidae, is transformed to export cecropin A, an insect immune peptide. Cecropin A is active against Trypanosoma cruzi, the causative agent of Chagas disease. While proof of concept has been achieved in laboratory studies, a rigorous and comprehensive risk assessment is required prior to consideration of field release. An important part of this assessment involves estimating probability of transgene horizontal transfer to environmental organisms (HGT. This article presents a two-part risk assessment methodology: a theoretical model predicting HGT in the gut of R. prolixus from the genetically transformed symbiont R. rhodnii to a closely related non-target bacterium, Gordona rubropertinctus, in the absence of selection pressure, and a series of laboratory trials designed to test the model. Results The model predicted an HGT frequency of less than 1.14 × 10-16 per 100,000 generations at the 99% certainty level. The model was iterated twenty times, with the mean of the ten highest outputs evaluated at the 99% certainty level. Laboratory trials indicated no horizontal gene transfer, supporting the conclusions of the model. Conclusions The model treats HGT as a composite event, the probability of which is determined by the joint probability of three independent events: gene transfer through the modalities of transformation, transduction, and conjugation. Genes are represented in matrices and Monte Carlo method and Markov chain analysis are used to simulate and evaluate environmental conditions. The model is intended as a risk assessment instrument and predicts HGT frequency of less than 1.14 × 10-16 per 100,000 generations. With laboratory studies that

  9. Nuevos aspectos del método de xenodiagnóstico con Rhodnius prolixus

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    Ernesto Osorno Mesa

    1963-04-01

    Full Text Available The efficiency of Xenodiagnostico is noted, as a biological method of making an etiological diagnosis of Chagas disease, It is pointed out that the fourth and fifth nymph stages are the most appropriate, not only because of the great amount of blood which they ingurgitate to repletion, but also because of the facility of the routine operations without the necessity of extraeting and placing the specimens in receptacles of superficial cleanliness in order to separate the full specimens from the empty ones. The advantages of a partial diet of blood is indicated in order to prevent the nymphs from becoming adults. The technique used in the study of spontaneous dejection in Rhodnius prolixus experimentally infected is described and the advantages noted. The article describes an original method "Dejectograma" of recording the total digestion of blood during one month in normal and infected fifth stage nymphs. The recording apparatus is an adapted thermograph which we call a "Dejectografo". Some observations are made concerning the discovery of evolved forms of S. cruzi, in several spontaneous dejections and the survival of metacyclic forms in hyaline for 30 hours between the slide and cover slide at a temperature of 150 C. Attention is called to the intermission of ejection of evolved forms of S. cruzi, with the conclusion that in order to avoid false negative results, dissection of the digestive tracts is necessary in these cases. The possibility of complete studies is set forth, aided by the techniques explained, and along the lines of the few observations made from pilot experiments.

  10. Jaburetox-induced toxic effects on the hemocytes of Rhodnius prolixus (Hemiptera: Reduviidae).

    Science.gov (United States)

    Moyetta, Natalia R; Broll, Valquiria; Perin, Ana Paula A; Uberti, Augusto F; Coste Grahl, Matheus V; Staniscuaski, Fernanda; Carlini, Celia R; Fruttero, Leonardo L

    2017-10-01

    Jaburetox is a recombinant peptide derived from a Canavalia ensiformis urease that presents toxic effects upon several species of insects, phytopathogenic fungi and yeasts of medical importance. So far, no toxicity of Jaburetox to mammals has been shown. Previous reports have identified biochemical targets of this toxic peptide in insect models, although its mechanism of action is not completely understood. In this work, we aimed to characterize the effects of Jaburetox in hemolymphatic insect cells. For this purpose, the model insect and Chagas' disease vector Rhodnius prolixus was used. In vivo and in vitro experiments indicated that Jaburetox interacts with a subset of hemocytes and it can be found in various subcellular compartments. In insects injected with Jaburetox there was an increase in the gene expression of the enzymes UDP-N-acetylglucosamine pyrophosphorylase (UAP), chitin synthase and nitric oxide synthase (NOS). Nevertheless, the expression of NOS protein, the enzyme activities of UAP and acid phosphatase (a possible link between UAP and NOS) as well as the phosphorylation state of proteins remained unchanged upon the in vivo Jaburetox treatment. Nitric oxide (NO) imaging using fluorescent probes showed that Jaburetox augmented NO production in the hemocyte aggregates when compared to controls. Even though Jaburetox activated the hemocytes, as demonstrated by wheat germ agglutinin binding assays, the peptide did not lead to an increase of their phagocytic behavior. Taken together, these findings contribute to our understanding of toxic effects of Jaburetox, a peptide with biotechnological applications and a prospective tool for rational insect control. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Transcriptome and gene expression profile of ovarian follicle tissue of the triatomine bug Rhodnius prolixus

    Science.gov (United States)

    Medeiros, Marcelo N.; Logullo, Raquel; Ramos, Isabela B.; Sorgine, Marcos H. F.; Paiva-Silva, Gabriela O.; Mesquita, Rafael D.; Machado, Ednildo Alcantara; Coutinho, Maria Alice; Masuda, Hatisaburo; Capurro, Margareth L.; Ribeiro, José M.C.; Cardoso Braz, Glória Regina; Oliveira, Pedro L

    2013-01-01

    Insect oocytes grow in close association with the ovarian follicular epithelium (OFE), which escorts the oocyte during oogenesis and is responsible for synthesis and secretion of the eggshell. We describe a transcriptome of OFE of the triatomine bug Rhodnius prolixus, a vector of Chagas disease, to increase our knowledge of the role of FE in egg development. Random clones were sequenced from a cDNA library of different stages of follicle development. The transcriptome showed high commitment to transcription, protein synthesis, and secretion. The most abundant cDNA was a secreted (S) small, proline-rich protein with maximal expression in the vitellogenic follicle, suggesting a role in oocyte maturation. We also found Rp45, a chorion protein already described, and a putative chitin-associated cuticle protein that was an eggshell component candidate. Six transcripts coding for proteins related to the unfolded protein response (UPR) by were chosen and their expression analyzed. Surprisingly, transcripts related to UPR showed higher expression during early stages of development and downregulation during late stages, when transcripts coding for S proteins participating in chorion formation were highly expressed. Several transcripts with potential roles in oogenesis and embryo development are also discussed. We propose that intense protein synthesis at the FE results in reticulum stress (RS) and that lowering expression of a set of genes related to cell survival should lead to degeneration of follicular cells at oocyte maturation. This paradoxical suppression of UPR suggests that ovarian follicles may represent an interesting model for studying control of RS and cell survival in professional S cell types. PMID:21736942

  12. MDL28170, a calpain inhibitor, affects Trypanosoma cruzi metacyclogenesis, ultrastructure and attachment to Rhodnius prolixus midgut.

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    Vítor Ennes-Vidal

    Full Text Available BACKGROUND: Trypanosoma cruzi is the etiological agent of Chagas' disease. During the parasite life cycle, many molecules are involved in the differentiation process and infectivity. Peptidases are relevant for crucial steps of T. cruzi life cycle; as such, it is conceivable that they may participate in the metacyclogenesis and interaction with the invertebrate host. METHODOLOGY/PRINCIPAL FINDINGS: In this paper, we have investigated the effect of the calpain inhibitor MDL28170 on the attachment of T. cruzi epimastigotes to the luminal midgut surface of Rhodnius prolixus, as well as on the metacyclogenesis process and ultrastructure. MDL28170 treatment was capable of significantly reducing the number of bound epimastigotes to the luminal surface midgut of the insect. Once the cross-reactivity of the anti-Dm-calpain was assessed, it was possible to block calpain molecules by the antibody, leading to a significant reduction in the capacity of adhesion to the insect guts by T. cruzi. However, the antibodies were unable to interfere in metacyclogenesis, which was impaired by the calpain inhibitor presenting a significant reduction in the number of metacyclic trypomastigotes. The calpain inhibitor also promoted a direct effect against bloodstream trypomastigotes. Ultrastructural analysis of epimastigotes treated with the calpain inhibitor revealed disorganization in the reservosomes, Golgi and plasma membrane disruption. CONCLUSIONS/SIGNIFICANCE: The presence of calpain and calpain-like molecules in a wide range of organisms suggests that these proteins could be necessary for basic cellular functions. Herein, we demonstrated the effects of MDL28170 in crucial steps of the T. cruzi life cycle, such as attachment to the insect midgut and metacyclogenesis, as well as in parasite viability and morphology. Together with our previous findings, these results help to shed some light on the functions of T. cruzi calpains. Considering the potential roles of

  13. Rhodnius prolixus en Nicaragua: distribución geográfica, control y vigilancia entre 1998 y 2009 Rhodnius prolixus in Nicaragua: geographical distribution, control, and surveillance, 1998-2009

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    Kota Yoshioka

    2011-11-01

    Full Text Available OBJETIVO: Presentar la perspectiva general del control de Rhodnius prolixus, el principal vector en la transmisión de la enfermedad de Chagas en Centroamérica, durante el período 1998-2009 en Nicaragua. Describir el control vectorial realizado y presentar la distribución geográfica de las localidades infestadas. MÉTODOS: Se estudió y analizó la información disponible en el Ministerio de Salud de Nica ragua. Se visualizó la distribución geográfica de R. prolixus mediante el programa visualiza dor de mapas Quantum GIS 1.5.0. RESULTADOS: Se determinó que 59 localidades en 14 municipios de 8 departamentos presen taron antecedentes de infestación con R. prolixus entre 1998 y 2009. La altitud de las locali dades infestadas oscila entre 160 y 1 414 metros sobre el nivel del mar. Se han tratado con más de dos ciclos de control químico 56 localidades. En el segundo ciclo de rociamiento se detectó la presencia del vector, pero durante el tercer ciclo no se lo encontró en ninguna localidad. CONCLUSIONES: La mayor concentración geográfica de R. prolixus se observó en dos depar tamentos de la región norte: Madriz y Nueva Segovia. La cantidad de localidades infestadas es menor en Nicaragua que en otros países centroamericanos. El control químico ha sido exitoso en las localidades intervenidas, pero es necesario fortalecer el sistema de vigilancia institucio nal y comunitaria tanto para vigilar la reinfestación con R. prolixus como para ampliar la cobertura del control vectorialOBJECTIVE: Present an overview of the control of Rhodnius prolixus, the principal vector in the transmission of Chagas' disease in Central America, during the period 1998-2009 in Nicaragua. Describe the vector control carried out and the geographical distribution of the infested localities. METHODS: The available information in Nicaragua's Ministry of Health was studied and analyzed. The geographical distribution of R. prolixus was visualized using the Quantum

  14. In vitro and in vivo documentation of quantum dots labeled Trypanosoma cruzi--Rhodnius prolixus interaction using confocal microscopy.

    Science.gov (United States)

    Feder, Denise; Gomes, Suzete A O; de Thomaz, André A; Almeida, Diogo B; Faustino, Wagner M; Fontes, Adriana; Stahl, Cecília V; Santos-Mallet, Jacenir R; Cesar, Carlos L

    2009-12-01

    Semiconductor quantum dots (QDs) are highly fluorescent nanocrystals markers that allow long photobleaching and do not destroy the parasites. In this paper, we used fluorescent core shell quantum dots to perform studies of live parasite-vector interaction processes without any observable effect on the vitality of parasites. These nanocrystals were synthesized in aqueous medium and physiological pH, which is very important for monitoring live cells activities, and conjugated with molecules such as lectins to label specific carbohydrates involved on the parasite-vector interaction. These QDs were successfully used for the study of in vitro and in vivo interaction of Trypanosoma cruzi and the triatomine Rhodnius prolixus. These QDs allowed us to acquire real time confocal images sequences of live T. cruzi-R. prolixus interactions for an extended period, causing no damage to the cells. By zooming to the region of interest, we have been able to acquire confocal images at the three to four frames per second rate. Our results show that QDs are physiological fluorescent markers capable to label living parasites and insect vector cells. QDs can be functionalized with lectins to specifically mark surface carbohydrates on perimicrovillar membrane of R. prolixus to follow, visualize, and understand interaction between vectors and its parasites in real-time.

  15. Identification and expression of the CCAP receptor in the Chagas' disease vector, Rhodnius prolixus, and its involvement in cardiac control.

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    Dohee Lee

    Full Text Available Rhodnius prolixus is the vector of Chagas' disease, by virtue of transmitting the parasite Trypanosoma cruzi. There is no cure for Chagas' disease and therefore controlling R. prolixus is currently the only method of prevention. Understanding the physiology of the disease vector is an important step in developing control measures. Crustacean cardioactive peptide (CCAP is an important neuropeptide in insects because it has multiple physiological roles such as controlling heart rate and modulating ecdysis behaviour. In this study, we have cloned the cDNA sequence of the CCAP receptor (RhoprCCAPR from 5(th instar R. prolixus and found it to be a G-protein coupled receptor (GPCR. The spatial expression pattern in 5(th instars reveals that the RhoprCCAPR transcript levels are high in the central nervous system, hindgut and female reproductive systems, and lower in the salivary glands, male reproductive tissues and a pool of tissues including the dorsal vessel, trachea, and fat body. Interestingly, the RhoprCCAPR expression is increased prior to ecdysis and decreased post-ecdysis. A functional receptor expression assay confirms that the RhoprCCAPR is activated by CCAP (EC50 = 12 nM but not by adipokinetic hormone, corazonin or an extended FMRFamide. The involvement of CCAP in controlling heartbeat frequency was studied in vivo and in vitro by utilizing RNA interference. In vivo, the basal heartbeat frequency is decreased by 31% in bugs treated with dsCCAPR. Knocking down the receptor in dsCCAPR-treated bugs also resulted in loss of function of applied CCAP in vitro. This is the first report of a GPCR knock-down in R. prolixus and the first report showing that a reduction in CCAPR transcript levels leads to a reduction in cardiac output in any insect.

  16. An Insight into the Transcriptome of the Digestive Tract of the Bloodsucking Bug, Rhodnius prolixus

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    Ribeiro, José M. C.; Genta, Fernando A.; Sorgine, Marcos H. F.; Logullo, Raquel; Mesquita, Rafael D.; Paiva-Silva, Gabriela O.; Majerowicz, David; Medeiros, Marcelo; Koerich, Leonardo; Terra, Walter R.; Ferreira, Clélia; Pimentel, André C.; Bisch, Paulo M.; Leite, Daniel C.; Diniz, Michelle M. P.; Junior, João Lídio da S. G. V.; Da Silva, Manuela L.; Araujo, Ricardo N.; Gandara, Ana Caroline P.; Brosson, Sébastien; Salmon, Didier; Bousbata, Sabrina; González-Caballero, Natalia; Silber, Ariel Mariano; Alves-Bezerra, Michele; Gondim, Katia C.; Silva-Neto, Mário Alberto C.; Atella, Georgia C.; Araujo, Helena; Dias, Felipe A.; Polycarpo, Carla; Vionette-Amaral, Raquel J.; Fampa, Patrícia; Melo, Ana Claudia A.; Tanaka, Aparecida S.; Balczun, Carsten; Oliveira, José Henrique M.; Gonçalves, Renata L. S.; Lazoski, Cristiano; Rivera-Pomar, Rolando; Diambra, Luis; Schaub, Günter A.; Garcia, Elói S.; Azambuja, Patrícia; Braz, Glória R. C.; Oliveira, Pedro L.

    2014-01-01

    The bloodsucking hemipteran Rhodnius prolixus is a vector of Chagas' disease, which affects 7–8 million people today in Latin America. In contrast to other hematophagous insects, the triatomine gut is compartmentalized into three segments that perform different functions during blood digestion. Here we report analysis of transcriptomes for each of the segments using pyrosequencing technology. Comparison of transcript frequency in digestive libraries with a whole-body library was used to evaluate expression levels. All classes of digestive enzymes were highly expressed, with a predominance of cysteine and aspartic proteinases, the latter showing a significant expansion through gene duplication. Although no protein digestion is known to occur in the anterior midgut (AM), protease transcripts were found, suggesting secretion as pro-enzymes, being possibly activated in the posterior midgut (PM). As expected, genes related to cytoskeleton, protein synthesis apparatus, protein traffic, and secretion were abundantly transcribed. Despite the absence of a chitinous peritrophic membrane in hemipterans - which have instead a lipidic perimicrovillar membrane lining over midgut epithelia - several gut-specific peritrophin transcripts were found, suggesting that these proteins perform functions other than being a structural component of the peritrophic membrane. Among immunity-related transcripts, while lysozymes and lectins were the most highly expressed, several genes belonging to the Toll pathway - found at low levels in the gut of most insects - were identified, contrasting with a low abundance of transcripts from IMD and STAT pathways. Analysis of transcripts related to lipid metabolism indicates that lipids play multiple roles, being a major energy source, a substrate for perimicrovillar membrane formation, and a source for hydrocarbons possibly to produce the wax layer of the hindgut. Transcripts related to amino acid metabolism showed an unanticipated priority for

  17. An insight into the transcriptome of the digestive tract of the bloodsucking bug, Rhodnius prolixus.

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    José M C Ribeiro

    Full Text Available The bloodsucking hemipteran Rhodnius prolixus is a vector of Chagas' disease, which affects 7-8 million people today in Latin America. In contrast to other hematophagous insects, the triatomine gut is compartmentalized into three segments that perform different functions during blood digestion. Here we report analysis of transcriptomes for each of the segments using pyrosequencing technology. Comparison of transcript frequency in digestive libraries with a whole-body library was used to evaluate expression levels. All classes of digestive enzymes were highly expressed, with a predominance of cysteine and aspartic proteinases, the latter showing a significant expansion through gene duplication. Although no protein digestion is known to occur in the anterior midgut (AM, protease transcripts were found, suggesting secretion as pro-enzymes, being possibly activated in the posterior midgut (PM. As expected, genes related to cytoskeleton, protein synthesis apparatus, protein traffic, and secretion were abundantly transcribed. Despite the absence of a chitinous peritrophic membrane in hemipterans - which have instead a lipidic perimicrovillar membrane lining over midgut epithelia - several gut-specific peritrophin transcripts were found, suggesting that these proteins perform functions other than being a structural component of the peritrophic membrane. Among immunity-related transcripts, while lysozymes and lectins were the most highly expressed, several genes belonging to the Toll pathway - found at low levels in the gut of most insects - were identified, contrasting with a low abundance of transcripts from IMD and STAT pathways. Analysis of transcripts related to lipid metabolism indicates that lipids play multiple roles, being a major energy source, a substrate for perimicrovillar membrane formation, and a source for hydrocarbons possibly to produce the wax layer of the hindgut. Transcripts related to amino acid metabolism showed an unanticipated

  18. Impact of residual spraying on Rhodnius prolixus and Triatoma dimidiata in the department of Zacapa in Guatemala

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    J Nakagawa

    2003-03-01

    Full Text Available As a vector control program to control Chagas disease in Guatemala, residual spraying of Rhodnius prolixus and Triatoma dimidiata was performed, and its impact was measured in the department of Zacapa. In order to identify infested villages and determine the degree of infestation, a baseline entomological survey to identify municipalities infested with vectors followed by an additional vector survey in areas known to be infested was conducted. Residual spraying using pyrethroid insecticides was performed at all the villages identified as being infested with the vectors. The residual spraying was shown to be highly effective against both vectors by the decrease in infestation indices after spraying. Analysis of the cost-effectiveness of the spraying showed that the average cost of insecticides per house is high when compared with that in Southern Cone countries.

  19. Short and long-term effects of azadirachtin A on development and egg production of Rhodnius prolixus

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    Eloi S. Garcia

    1990-03-01

    Full Text Available Azadirachtin A was given through a blood meal to 4th-instar larvae and to adult females of Rhodnius prolixus. Development (ecdysis and egg production were inhibited in a dose-dependent manner. Long-term experiments with subsequent four feedings on azadirachtin-free blood were performed with 4th-instar larvae and with adult females. Only in the low-dose azadirachtin larval groups (0.01 and 0.1 microng/ml of blood, development was partially restored; after a single 1.0 microng/ml treatment about 50% of the treated larvae were still alive 120 days later without any adult emergence. Similarly fed females had a dose-dependent lower survival and egg deposition rate. The results are discussed in relation to the mode of azadirachtin A action.

  20. Elemental content changes in hemolymph of Rhodnius prolixus due to mercury contamination: a study using SR-TXRF

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    Mantuano, A.; Oliveira, A.P.; Barroso, R.C. [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil); Almeida, A.P.; Braz, D.; Cardoso, S.C. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Figueiredo, M.B.; Azambuja, P. [Fundacao Instituto Osvaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ (Brazil); Gonzalez, M.S. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil)

    2012-07-01

    Full text: In recent years, the effects of pollution on the health of humans and other vertebrates have been extensively studied. However, the effects on some invertebrates are comparatively unknown. Research has demonstrated that toxic metals interfere with the reproduction, development and immune defenses of some terrestrial and marine invertebrates. Depending on environmental conditions, pollution produces chronic and acute effects on different systems and organs of animals. In general, some more toxic elements like arsenic, cadmium, lead, mercury and nickel in contact with organisms change cellular structures, enzyme activities, and in some cases destroy the physiological integrities of the tissues. In insects, the effects of pollutants depend upon the species studied. In this work, we investigated the changes in elemental contents in the hemolymph of Rhodnius prolixus on 2 and 5 days after feeding on blood containing mercury chloride. R. Prolixus is an obligated hematophagous Hemiptera and one of the most important insect vectors of trypanosoma cruzi, the causative agent of Chagas disease. The SR-TXRF measurements were performed at the X-ray fluorescence (XRF) beamline facility in Brazilian Synchrotron Light Laboratory LNLS/Brazil. The major elements Cl, K, Ca, Mn, Fe, Cu, Zn, Se, Br, Rb, K were found in all hemolymph samples analysed. Insects treated with HgCl2 had reduced Cl and Ca levels, whereas the same treatment had enhanced Br levels in comparison with non- treated control insects. (author)

  1. Fungal flora of the digestive tract of Rhodnius prolixus, Rhodnius neglectus, Diptelanogaster maximus and Panstrongylus megistus, vectors of Trypanosoma cruzi, Chagas, 1909 Flora fúngica do trato digestivo de Rhodnius prolixus, Rhodnius neglectus, Diptelanogaster maximus e Panstrongylus megistus vetores de Trypanosoma cruzi, Chagas 1909

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    Aurea Maria Lage de Moraes

    2004-12-01

    Full Text Available This paper reports a study on the mycobiota in the digestive tract of four important species of triatomines: Rhodnius prolixus, R. neglectus, Diptelanogaster maximus and Panstrongylus megistus. The digestive tracts of 90 adults and 425 nymphs of these four triatomine species were studied and 365 fungal strains were isolated. The genera with the greatest number of species were Aspergillus, Penicillium (14 species in each genus, Acremonium and Cladosporium (three species in each genus, and the most frequent species, in decreasing order, were Aspergillus awamori, Penicillium corylophilum, Cladosporium herbarum and Aspergillus niger. It was concluded that, among the isolated fungi, Aspergillus niger and Penicillium corylophilum might be part of the natural flora of the digestive tract of triatomines.Um estudo da micobiota do trato digestivo de quatro importantes espécies de triatomíneos, Rhodnius prolixus, R. neglectus, Diptelanogaster maximus e Panstrongylus megistus, foi realizado. Foram examinados os tratos digestivos de 90 adultos e 425 ninfas destas espécies de triatomíneos e 365 cepas fúngicas foram isoladas. Os gêneros com o maior número de espécies encontradas foram Aspergillus, Penicillium (14 espécies cada, Acremonium e Cladosporium (3 espécies cada e as espécies mais freqüentes, em ordem decrescente, foram Aspergillus awamori, Penicillium corylophilum, Cladosporium herbarum e Aspergillus niger. Dentre os fungos isolados, concluímos que Aspergillus niger e Penicillium corylophilum possam fazer parte da flora natural do trato digestivo destes triatomíneos.

  2. Differential effects of ambient temperature on warm cell responses to infrared radiation in the bloodsucking bug Rhodnius prolixus.

    Science.gov (United States)

    Zopf, Lydia M; Lazzari, Claudio R; Tichy, Harald

    2014-03-01

    Thermoreceptors provide animals with background information about the thermal environment, which is at least indirectly a prerequisite for thermoregulation and assists bloodsucking insects in the search for their host. Recordings from peg-in-pit sensilla and tapered hairs on the antennae of the bug Rhodnius prolixus revealed two physiologically different types of warm cells. Both types responded more strongly to temperature pulses produced by switching between two air streams at different constant temperatures than to infrared radiation pulses employed in still air. In addition, both warm cells were better able to discriminate small changes in air temperature than in infrared radiation. As convective and radiant heat determines the discharge, it is impossible for a single warm cell to signal the nature of the stimulus unequivocally. Individual responses are ambiguous, not with regard to temperature change, but with regard to its source. We argue that the bugs use mechanical flow information to differentiate between pulses of convective and radiant heat. However, if pulses of radiant heat occur together with a constant temperature air stream, the mechanical cues would not allow avoiding ambiguity that convective heat introduces into radiant heat stimulation. In this situation, the warm cell in the tapered hairs produced stronger responses than those in the peg-in-pit sensilla. The reversal in the excitability of the two types of warm cells provides a criterion by which to distinguish the combination of convective and radiant heat from the stimuli presented alone.

  3. The distribution and function of serotonin in the large milkweed bug, Oncopeltus fasciatus. a comparative study with the blood-feeding bug, Rhodnius prolixus.

    Science.gov (United States)

    Miggiani, L; Orchard, I; TeBrugge, V

    1999-11-01

    The blood-feeding hemipteran, Rhodnius prolixus, ingests a large blood meal at the end of each larval stage. To accommodate and process this meal, its cuticle undergoes plasticisation, and its gut and Malpighian tubules respectively absorb and secrete a large volume of water and salts for rapid diuresis. Serotonin has been found to be integral to the feeding process in this animal, along with a diuretic peptide(s). The large milkweed bug, Oncopeltus fasciatus, tends to feed in a more continuous and abstemious manner, and therefore may have different physiological requirements than the blood feeder. Unlike R. prolixus, O. fasciatus is lacking serotonin-like immunoreactive dorsal unpaired median neurons in the mesothoracic ganglionic mass, and lacks serotonin-like immunoreactive neurohaemal areas and processes on the abdominal nerves, integument, salivary glands, and anterior junction of the foregut and crop. The salivary glands and crop do, however, respond to serotonin with increased levels of cAMP, while the integument and Malpighian tubules do not. In addition, O. fasciatus Malpighian tubules respond to both O. fasciatus and R. prolixus partially purified CNS extracts, which are likely to contain any native diuretic peptides. Thus, while serotonin and diuretic peptides may be involved in tubule control in R. prolixus, the latter may be of greater importance in O. fasciatus.

  4. Efecto teratogénico y toxico de ácidos grasos de cadena corta insaturados, en Rhodnius prolixus Teratogenic and toxic effect of unsaturated fatty acids of short chain, in Rhodnius prolixus

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    Ivonne Gomez

    1985-12-01

    Full Text Available Se estudia el papel teratogénico de dos ácidos grasos insaturados de cadena corta, ácido octinoico y ácido undecilénico, sobre insectos de metamorfosis hemimetábola, Rhodnius prolixus (Hemiptera. La penetración de los ácidos, se realiza a través de la cutícula del abdomen y de los tarsos, se presenta como una acción independiente del grado de distensión de la misma, ya que sus efectos se registran tanto en los insectos repletos, como en los hambrientos; tanto en los tratados tópicamente como en aquellos donde la droga se aplicó al papel de soporte. Los ácidos estudiados aparentemente no afectan la formación de la cutícula, ni la melanización, como tampoco afecta el proceso de la muda. Los daños inducidos por estos ácidos se presentam al azar tanto en los apéndices locomotores como en los cefálicos, observándose un desplazamiento a la proboscide a medida que se incrementa la dosis. De las malformaciones en la proboscide, es el labio el mas dramáticamente dañado, aunque también se presentan daños en los otros apéndices bucales, aisladamente o junto con el daño del labio. El daño en los apéndices locomotores está frecuentemente desplazado al segundo y tercer par de patas, mientras que el par, fue el menos afectado. El ácido octinoico se comportó como teratogénico en las dosis que fueron letales para el insecto con el ácido undecilénico.The teratogenic role of two short-chain unsaturated fatty acids, octinoic acid and undecylenic acid on the hemimetabolic metamorphosis of the insect Rhodnius prolixus (Hemipter is studied. The acids penetrate through the cuticle of the abdomen and tarsi, independently of the amount of distention. The effects are registered equally in satiated or hungry insects, in those treated topically or in those where the treatment was applied to the support paper. The acids apparently do not affect the formation of the cuticle, melanization, nor the metamorphic process. The damage induced by

  5. Allosteric regulation of 6-phosphofructo-1-kinase activity of fat body and flight muscle from the bloodsucking bug Rhodnius prolixus

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    Gutemberg G. Alves

    2007-03-01

    Full Text Available 6-phosphofructo-1-kinase (phosphofructokinase; PFK activity from Rhodnius prolixus, a haematophagous insect which is usually a poor flyer, was measured and compared in two metabolically active tissues - flight muscle and fat body. The activity of this important regulatory glycolytic enzyme was much more pronounced in muscle (15.1 ± 1.4 U/mg than in fat body extracts (3.6±0.4 U/mg, although the latter presented higher levels of enzyme per protein content, as measured by western-blotting. Muscle extracts are more responsible than fat body to ATP and fructose 6-phosphate, both substrates of PFK. Allosteric regulation exerted by different effectors such as ADP, AMP and fructose 2,6-phosphate presented a singular pattern for each tissue. Optimal pH (8.0-8.5 and sensitivity to pH variation was very similar, and citrate was unable to inhibit PFK activity in both extracts. Our results suggest the existence of a particular PFK activity for each tissue, with regulatory patterns that are consistent with their physiological roles.A atividade da fosfofrutocinase (PFK de Rodnius prolixus, um inseto hematófago, o qual vôa somente pequenas distâncias, foi medida e comparada em dois tecidos metabolicamente ativos - músculo de asa e corpo gorduroso. A atividade desta importante enzima glicolítica regulatória foi muito mais pronunciada em músculo de asa (15,1 ±1,4 U/mg do que em extrato de corpo gorduroso (3,6 ±0,4 U/mg embora este último tenha apresentado níveis mais altos da enzima por quantidade de proteína, como medido por western-blotting. Extratos de músculo foram mais responsivos do que corpo gorduroso para ATP e frutose-6-fosfato, ambos substratos da PFK. A regulação alostérica exercida por diferentes efetores tais como ADP, AMP, frutose-2,6-bisfosfato apresentou um padrão singular para cada tecido. O pH ótimo (8,0-8,5 e a sensibilidade a variações de pH, foram muito similares e o citrato foi incapaz de inibir a atividade da PFK em

  6. Técnica para extraer cantidad apreciable de hemolinfa y sacar fácilmente glándulas salivales en ninfas de quinto estadio y adultos de Rhodnius Prolixus

    Directory of Open Access Journals (Sweden)

    Ernesto Osorno Mesa

    1965-07-01

    Full Text Available Se describen minuciosamente los diferentes pasos para extracción de hemolinfa con micropipetas, en ninfas de 5º estadio y adultos de Rhodnius prolixus, lo mismo que para el aislamiento de las glándulas salivales. Se anotan las ventajas y aplicaciones de estas técnicas, en investigaciones parasitológicas, especialmente sobre Trypanosomiasis.

  7. Cloning and Functional Characterization of Octβ2-Receptor and Tyr1-Receptor in the Chagas Disease Vector, Rhodnius prolixus

    Directory of Open Access Journals (Sweden)

    Sam Hana

    2017-09-01

    Full Text Available Octopamine and tyramine, both biogenic amines, are bioactive chemicals important in diverse physiological processes in invertebrates. In insects, octopamine and tyramine operate analogously to epinephrine and norepinephrine in the vertebrates. Octopamine and tyramine bind to G-protein coupled receptors (GPCRs leading to changes in second messenger levels and thereby modifying the function in target tissues and insect behavior. In this paper, we report the cDNA sequences of two GPCRs, RhoprOctβ2-R, and RhoprTyr1-R, have been cloned and functionally characterized from Rhodnius prolixus. Octopamine and tyramine each activate RhoprOctβ2-R and RhoprTyr1-R in a dose-dependent manner. Octopamine is one order of magnitude more potent than tyramine in activating RhoprOctβ2-R. Tyramine is two orders of magnitude more potent than octopamine in activating RhoprTyr1-R. Phentolamine and gramine significantly antagonize RhoprOctβ2-R, whereas yohimbine and phenoxybenzamine are effective blockers of RhoprTyr1-R. The transcripts of both receptors are enriched in the central nervous system (CNS and are expressed throughout the adult female reproductive system. It has been shown in other insects that Octβ2-R is essential for processes such as ovulation and fertilization. We previously reported that octopamine and tyramine modulate oviducts and bursa contractions in R. prolixus. Our data confirm the importance of octopamine and tyramine signaling in the reproductive system of R. prolixus.

  8. Efecto de la alternación de fuentes sanguíneas sobre la fecundidad y la fertilidad de Rhodnius prolixus Stal (Heteroptera: Reduviidae

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    Elis José Aldana

    2009-04-01

    Full Text Available En este trabajo se evidencia que si el éxito reproductivo de Rhodnius prolixus Stal está relacionado a la fuente alimentaria, entonces las necesidades biológicas del insecto son satisfechas en modos diferentes según el tipo de alternancia entre dichas fuentes de alimentación; tales diferencias son reveladas mediante los cambios en fertilidad y fecundidad del insecto. Se realizaron nueve alternancias, en cada una se suministraron dos alimentaciones, en unas se alternó la fuente de alimentación y en los controles se suministraron dos alimentaciones con la misma fuente. Las fuentes alimentarias fueron paloma, gallina y humano, esta última mediante un aparato de alimentación artificial; estas fuentes se escogieron en el supuesto que son fuentes alimentarias encontradas en los ecotopos silvestre, peri-domicilio y domicilio respectivamente. En todos los tipos de alternancia se encontró una relación lineal entre la fecundidad y el tiempo de oviposición, que la relación entre cantidad de sangre ingerida y la fecundidad varían, que la tasa de fecundidad aumenta en la segunda alimentación respecto a la primera y que la fertilidad fue superior al 95 %. Effects of alternating blood sources on fecundity and fertility of Rhodnius prolixus Stal (Heteroptera: ReduviidaeIn this work it is argued that if the reproductive parameters of Rhodnius prolixus Stal are related to the blood source upon which it feeds, then the insects biological needs must be satisfied in different ways by the alternation between blood sources, reveled through changes in the fecundity and fertility of individuals of this insect species. Nine experiments were conducted, each one consisting of two feedings, in which the blood source were either alternated or remained the same. The meal sources used were pigeon, hen and human blood, selected according to the resources found in the sylvatic, peri-domestic and domestic ecotopes respectively. It was found that the quantity of

  9. Silencing of Iron and Heme-Related Genes Revealed a Paramount Role of Iron in the Physiology of the Hematophagous Vector Rhodnius prolixus

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    Ana B. Walter-Nuno

    2018-02-01

    Full Text Available Iron is an essential element for most organisms However, free iron and heme, its complex with protoporphyrin IX, can be extremely cytotoxic, due to the production of reactive oxygen species, eventually leading to oxidative stress. Thus, eukaryotic cells control iron availability by regulating its transport, storage and excretion as well as the biosynthesis and degradation of heme. In the genome of Rhodnius prolixus, the vector of Chagas disease, we identified 36 genes related to iron and heme metabolism We performed a comprehensive analysis of these genes, including identification of homologous genes described in other insect genomes. We observed that blood-meal modulates the expression of ferritin, Iron Responsive protein (IRP, Heme Oxygenase (HO and the heme exporter Feline Leukemia Virus C Receptor (FLVCR, components of major pathways involved in the regulation of iron and heme metabolism, particularly in the posterior midgut (PM, where an intense release of free heme occurs during the course of digestion. Knockdown of these genes impacted the survival of nymphs and adults, as well as molting, oogenesis and embryogenesis at different rates and time-courses. The silencing of FLVCR caused the highest levels of mortality in nymphs and adults and reduced nymph molting. The oogenesis was mildly affected by the diminished expression of all of the genes whereas embryogenesis was dramatically impaired by the knockdown of ferritin expression. Furthermore, an intense production of ROS in the midgut of blood-fed insects occurs when the expression of ferritin, but not HO, was inhibited. In this manner, the degradation of dietary heme inside the enterocytes may represent an oxidative challenge that is counteracted by ferritins, conferring to this protein a major antioxidant role. Taken together these results demonstrate that the regulation of iron and heme metabolism is of paramount importance for R. prolixus physiology and imbalances in the levels of

  10. Elemental changes in hemolymph and urine of Rhodnius prolixus induced by in-vitro exposure to mercury: A study using SR-TXRF

    Energy Technology Data Exchange (ETDEWEB)

    Mantuano, Andrea; Barroso, Regina C. [Physics Institute/State University of Rio de Janeiro (UERJ), RJ (Brazil); Almeida, Andre P. de; Braz, Delson [Nuclear Engineering Program/COPPE/Federal University of Rio de Janeiro, RJ (Brazil); Cardoso, Simone C. [Physics Institute/Federal University of Rio de Janeiro, RJ (Brazil); Penna, Patricia A.; Gonzalez, Marcelo S. [Laboratory of Biochemistry and Physiology of Insects/Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    Full text: In the last years have been studied the effects of the pollution of humans and others vertebrates, however, the effects on invertebrates are poorly knows. Some pollutants introduced in aquatic and terrestrial ecosystems are potentially toxic to living organisms. Almost the environmental pollutants, the heavy metals are not degradable and can persist during long time of many ecosystems causing ecologic changes often disastrous to species that habit there. Actually some works has shown that the heavy metals beyond be toxic and interfere on development and reproduction of some species of terrestrial and marine invertebrates. When are present in cells, the chemical form and connection type of metals are critical factors that determinate the toxicity. So, the ambient pollution has chronic effects and acute of animals health and can affect any systems and organs. The intoxications that current often are caused by aluminum, arsenic, barium, beryllium, cadmium, lead, mercury and nickel. Know that these elements can change cellular structures, enzymes and replace metal cofactors in enzyme activities. In insects, the effects of pollution change according to specie studied. The pollution can act on the weight reduction and increasing the relative growth rate. In this work, we investigated the effect of mercury exposure on the elemental content in hemolymph and urine of Rhodnius prolixus the insect vector of Chagas' disease, which is one of the most important vectors in Latin American and also, the most well-know studied insect in terms of both physiology and vector-parasite interactions. Five-stage nymphs of Rhodnius prolixus were collected from colony of a Laboratory Physiology and Biochemistry of Insects, Institute Oswaldo Cruz RJ. For treatment of insects, mercury chloride has been added to rabbit blood. After feeding the nymphs were separated and packed for two days for collection of hemolymph and urine. The SR-TXRF measurements were performed at the X

  11. Elemental changes in hemolymph and urine of Rhodnius prolixus induced by in-vitro exposure to mercury: A study using SR-TXRF

    International Nuclear Information System (INIS)

    Mantuano, Andrea; Barroso, Regina C.; Almeida, Andre P. de; Braz, Delson; Cardoso, Simone C.; Penna, Patricia A.; Gonzalez, Marcelo S.

    2011-01-01

    Full text: In the last years have been studied the effects of the pollution of humans and others vertebrates, however, the effects on invertebrates are poorly knows. Some pollutants introduced in aquatic and terrestrial ecosystems are potentially toxic to living organisms. Almost the environmental pollutants, the heavy metals are not degradable and can persist during long time of many ecosystems causing ecologic changes often disastrous to species that habit there. Actually some works has shown that the heavy metals beyond be toxic and interfere on development and reproduction of some species of terrestrial and marine invertebrates. When are present in cells, the chemical form and connection type of metals are critical factors that determinate the toxicity. So, the ambient pollution has chronic effects and acute of animals health and can affect any systems and organs. The intoxications that current often are caused by aluminum, arsenic, barium, beryllium, cadmium, lead, mercury and nickel. Know that these elements can change cellular structures, enzymes and replace metal cofactors in enzyme activities. In insects, the effects of pollution change according to specie studied. The pollution can act on the weight reduction and increasing the relative growth rate. In this work, we investigated the effect of mercury exposure on the elemental content in hemolymph and urine of Rhodnius prolixus the insect vector of Chagas' disease, which is one of the most important vectors in Latin American and also, the most well-know studied insect in terms of both physiology and vector-parasite interactions. Five-stage nymphs of Rhodnius prolixus were collected from colony of a Laboratory Physiology and Biochemistry of Insects, Institute Oswaldo Cruz RJ. For treatment of insects, mercury chloride has been added to rabbit blood. After feeding the nymphs were separated and packed for two days for collection of hemolymph and urine. The SR-TXRF measurements were performed at the X

  12. X-ray cone beam microtomography for quantitative assessment of tracheal and pharyngeal volumes of Rhodnius prolixus

    International Nuclear Information System (INIS)

    Souza, Izabella Soares de

    2017-01-01

    In the past decade microcomputerized tomography imaging using synchrotron radiation has become a powerful technique to generate high resolution images of Rhodinus prolixus. Images of soft tissues (protocerebrum and muscles) and dense structures (pharynx, trachea and esophagus) of R. prolixus head have been obtained using synchrotron radiation microtomography in mono and polychromatic configuration, respectively. Advancements in conventional microtomography have increased the achievable resolution and contrast, making this relatively inexpensive and widely available technology potentially useful for studies of insect internal morphology. The main goal of this work was to provide a new set of high quality microtomographic images of R. prolixus achieved by means of a desktop X-ray microtomograph. It allows the three-dimensional visualization of important chitinized structures: pharynx and tracheae. Pharyngeal and tracheal volumes were quantitatively evaluated at different days (1, 4, 10, 15 and 20) after feeding. The results suggest that variation of average volumes could be attributed to insect hormone 20-hydroxy-ecdysone (20-OH-Ec) pulse at 11 days after feeding. Pharyngeal volumes decrease 3.80 times. On the other hand, tracheal volumes increase 1.78 times. Head total volume showed similar trends than trachea. (author)

  13. Application of synchrotron radiation phase-contrast microtomography with iodine staining to Rhodnius prolixus head during ecdysis period

    Science.gov (United States)

    Sena, G.; Nogueira, L. P.; Braz, D.; Colaço, M. V.; Azambuja, P.; Gonzalez, M. S.; Tromba, G.; Mantuano, A.; Costa, F. N.; Barroso, R. C.

    2018-05-01

    Synchrotron radiation phase-contrast microtomography (SR-PHC-CT) has become an important tool in studies of insects, mainly Rhodinius prolixus, the insect vector of Chagas disease. A previous work has shown that SR-PHC-CT is an excellent technique in studies about the ecdysis process of R.prolixus head. The term ecdysis refers to the set of behaviors by which an insect extracts itself from an old exoskeleton. The exoskeleton formation is indispensable for the evolutionary success of insect species, so failure to complete ecdysis will, in most cases result in death, making this process an excellent target in the search for new insect pest management strategies. Understanding the behavior of the ecdysis process is fundamental for the non-proliferation of Chagas disease. Despite it has been possible to identify the moulting process in the first work, main structures of the R.prolixus head could not be identified. In this work, it was developed a staining protocol which enabled the identification of these important structures using Iodine at SYRMEP beamline of ELETTRA. In the 3D images, it was possible to segment essential structures in the process of ecdysis. These structures have never been presented previously in the moulting period with SR-PHC-CT.

  14. Psammolestes arthuri NATURALMENTE INFECTADO CON Trypanosoma cruzi ENCONTRADO EN SIMPATRÍA CON Rhodnius prolixus Y Triatoma maculata EN NIDOS DE AVES EN EL ESTADO ANZOÁTEGUI, VENEZUELA I Psammolestes arthuri NATURALLY INFECTED WITH Trypanosoma cruzi FOUND IN SYMPATRY WITH Rhodnius prolixus AND Triatoma maculata ON BIRD NESTS IN ANZOÁTEGUI STATE, VENEZUELA

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    Pedro José Cruz-Guzmán

    2018-04-01

    Full Text Available In Venezuela, Chagas' disease is a public health problem with around 2 million people infected and more than 6 million under risk of infection. In this study the presence of the triatomid Psammolestes arthuri is reported in nests of different species of birds from rural communities of Anzoátegui State, some of them found naturally infected with Trypanosoma cruzi , in sympatry with other species of triatomines ( Rhodnius prolixus y Triatoma maculata . A total of 3,277 triatomine specimens were collected in 478 nests from 6 species of birds ( Phacellodomus rufifrons , Troglodytes aedon , Icterus icterus , I. nigrogularis , Cacicus cela y Psarocolius decumanus . It was found that 99.05% (3246/3277 of specimens were P. arthuri and 0.95% (31/3277 other triatomine species, from which 0.57% (19/3277 were R. prolixus and 0.37% (12/3277 T. mac ulata . Only 0.12% (4/3246 of P. arthuri were infected with T. cr u z i . The parasitological characterization of one T. cr u z i isolate in white male NMRI mice showed high affinity for cardiac, skeletal and smooth muscle cells, with a peak parasitemia of 2.4 x 10 4 parasites/ mL blood stream forms of T. cr u z i and 100% mortality of inoculated mice. This isolate was molecularly typed as belonging to TcIII genotype. The results show that in Anzoátegui State, P. arthuri predominantly feed on blood of birds, representing a low risk for vector transmission of Chagas' disease to humans

  15. Exploring the Role of Rhodtestolin, A Cardio-Inhibitor from the Testes of Rhodnius prolixus, in Relation to the Structure and Function of Reproductive Organs in Insect Vectors of Chagas Disease

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    Marli Maria Lima

    2013-10-01

    Full Text Available Rhodtestolin is a cardio-inhibitor that was first discovered in testes extracts of the blood-feeding insect, Rhodnius prolixus. Its role in reproduction remains unconfirmed, but if delivered to the female during spermatophore formation, it may serve to calm the female and/or relax the vaginal muscles to facilitate delivery and storage of the spermatophore. We describe here the anatomy of reproductive organs in R. prolixus and show that rhodtestolin is present in a low-molecular weight fraction of testes extracts separated by gel filtration, as well as in spermatophores delivered to the female during spermatophore formation. We also report that a rhodtestolin-like factor is present in the testes of R. brethesi, Triatoma dimidiata, T. klugi and Nesotriatoma bruneri, other Reduviidae, which are vectors of Chagas disease. Male secretions in insects are known to modify female behavior after copulation, and the presence of rhodtestolin in several genera of Reduviidae suggests that it plays an important role in reproductive success. Determining this role could lead to developing additional population control strategies for these bugs.

  16. Estructura poblacional y variabilidad genética de Rhodnius prolixus (Hemiptera: Reduviidae procedente de diferentes áreas geográficas de Colombia

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    Diana Carolina López

    2007-01-01

    Resultados. R. prolixus presenta variabilidad genética moderada (Fst 0,057-0,15, entre las poblaciones domiciliadas se encontraron tasas de migración (Nm>1 que revelan flujo genético. Se encontró diferenciación genética de moderada-alta entre la población silvestre de Casanare y las poblaciones domésticas del centro del país (Tolima y Cundinamarca. Conclusión. Las poblaciones domiciliadas de R. prolixus son homogéneas debido a que existe flujo genético entre éstas; lo cual es favorable para el control químico, mientras que la población silvestre agrupa aparte de las domiciliadas. Se evidencia la necesidad de estudiar la estructura genética de los focos silvestres, sus posibles rutas de dispersión y el riesgo epidemiológico que representan.

  17. Monitoring of the Parasite Load in the Digestive Tract of Rhodnius prolixus by Combined qPCR Analysis and Imaging Techniques Provides New Insights into the Trypanosome Life Cycle.

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    Felipe de Almeida Dias

    Full Text Available Here we report the monitoring of the digestive tract colonization of Rhodnius prolixus by Trypanosoma cruzi using an accurate determination of the parasite load by qPCR coupled with fluorescence and bioluminescence imaging (BLI. These complementary methods revealed critical steps necessary for the parasite population to colonize the insect gut and establish vector infection.qPCR analysis of the parasite load in the insect gut showed several limitations due mainly to the presence of digestive-derived products that are thought to degrade DNA and inhibit further the PCR reaction. We developed a real-time PCR strategy targeting the T. cruzi repetitive satellite DNA sequence using as internal standard for normalization, an exogenous heterologous DNA spiked into insect samples extract, to precisely quantify the parasite load in each segment of the insect gut (anterior midgut, AM, posterior midgut, PM, and hindgut, H. Using combined fluorescence microscopy and BLI imaging as well as qPCR analysis, we showed that during their journey through the insect digestive tract, most of the parasites are lysed in the AM during the first 24 hours independently of the gut microbiota. During this short period, live parasites move through the PM to establish the onset of infection. At days 3-4 post-infection (p.i., the parasite population begins to colonize the H to reach a climax at day 7 p.i., which is maintained during the next two weeks. Remarkably, the fluctuation of the parasite number in H remains relatively stable over the two weeks after refeeding, while the populations residing in the AM and PM increases slightly and probably constitutes the reservoirs of dividing epimastigotes.These data show that a tuned dynamic control of the population operates in the insect gut to maintain an equilibrium between non-dividing infective trypomastigote forms and dividing epimastigote forms of the parasite, which is crucial for vector competence.

  18. X-ray cone beam microtomography for quantitative assessment of tracheal and pharyngeal volumes of Rhodnius prolixus; Utilizacao da microtomografia computadorizada com feixe de raios-X conico para a determinacao quantitativa do volume da traqueia e faringe do Rhodnius prolixus

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Izabella Soares de

    2017-07-01

    In the past decade microcomputerized tomography imaging using synchrotron radiation has become a powerful technique to generate high resolution images of Rhodinus prolixus. Images of soft tissues (protocerebrum and muscles) and dense structures (pharynx, trachea and esophagus) of R. prolixus head have been obtained using synchrotron radiation microtomography in mono and polychromatic configuration, respectively. Advancements in conventional microtomography have increased the achievable resolution and contrast, making this relatively inexpensive and widely available technology potentially useful for studies of insect internal morphology. The main goal of this work was to provide a new set of high quality microtomographic images of R. prolixus achieved by means of a desktop X-ray microtomograph. It allows the three-dimensional visualization of important chitinized structures: pharynx and tracheae. Pharyngeal and tracheal volumes were quantitatively evaluated at different days (1, 4, 10, 15 and 20) after feeding. The results suggest that variation of average volumes could be attributed to insect hormone 20-hydroxy-ecdysone (20-OH-Ec) pulse at 11 days after feeding. Pharyngeal volumes decrease 3.80 times. On the other hand, tracheal volumes increase 1.78 times. Head total volume showed similar trends than trachea. (author)

  19. Rhodnius prolixus and Rhodnius robustus–like (Hemiptera ...

    Indian Academy of Sciences (India)

    2013-06-09

    Jun 9, 2013 ... non-directional deviations between the left and the right values of a ... 2011). For example, in Drosophila spp contradictory results have been .... of a lower selection pressure on individuals with reduced flying activity in ...

  20. Description of Rhodnius marabaensis sp. n. (Hemiptera, Reduviidae, Triatominae) from Pará State, Brazil

    Science.gov (United States)

    Souza, Eder dos Santos; Von Atzingen, Noé Carlos Barbosa; Furtado, Maria Betânia; de Oliveira, Jader; Nascimento, Juliana Damieli; Vendrami, Daniel Pagotto; Gardim, Sueli; da Rosa, João Aristeu

    2016-01-01

    Abstract Rhodnius marabaensis sp. n. was collected on 12 May 2014 in the Murumurú Environmental Reserve in the city of Marabá, Pará State, Brazil. This study was based on previous consultation of morphological descriptions of 19 Rhodnius species and compared to the identification key for the genus Rhodnius. The examination included specimens from 18 Rhodnius species held in the Brazilian National and International Triatomine Taxonomy Reference Laboratory in the Oswaldo Cruz Institute in Rio de Janeiro, Brazil. The morphological characteristics of the head, thorax, abdomen, genitalia, and eggs have been determined. Rhodnius prolixus and Rhodnius robustus were examined in more detail because the BLAST analysis of a cyt-b sequence shows they are closely related to the new species, which also occurs in the northern region of Brazil. The most notable morphological features that distinguish Rhodnius marabaensis sp. n. are the keel-shaped apex of the head, the length of the second segment of the antennae, the shapes of the prosternum, mesosternum and metasternum, the set of spots on the abdomen, the male genitalia, the posterior and ventral surfaces of the external female genitalia, and the morphological characteristics of the eggs. Rhodnius jacundaensis Serra, Serra & Von Atzingen (1980) nomen nudum specimens deposited at the Maraba Cultural Center Foundation - MCCF were examined and considered as a synonym of Rhodnius marabaensis sp. n. PMID:27833419

  1. Handbuch Stahl Auswahl, Verarbeitung, Anwendung

    CERN Document Server

    Bleck, Wolfgang

    2018-01-01

    Stahl ist der wichtigste Konstruktionswerkstoff. Im Maschinen- und Anlagenbau, Fahrzeugbau, Schiffbau, Stahlbau und in vielen anderen Industriebereichen ist er durch keinen anderen Werkstoff zu ersetzen. Für jeden Anwendungszweck gibt es passende Stahlsorten am Markt zu kaufen. Die Feinabstimmung der gewünschten Eigenschaften kann im weiteren Verarbeitungsprozess vorgenommen werden, bis der Werkstoff optimal den gewünschten Produktanforderungen entspricht. Die Anzahl der Möglichkeiten ist sehr groß und somit auch die Schwierigkeit, den genau passenden Stahl zu finden bzw. zu erzeugen. Das vorliegende Handbuch hilft Ihnen, dieses Problem zu lösen. Es zeigt u.a. - mit welchen systematischen Ansätzen und Hilfsmitteln Sie die in Frage kommende Stahlsorte eingrenzen können - die wichtigsten produktrelevanten Eigenschaften und Lieferformen - die werkstoffgerechte Weiterverarbeitung durch umformende und spanende Fertigungsprozesse und Wärmebehandlung - hunderte Anwendungsbeispiele aus Maschinen- und Anlage...

  2. Molecular characterisation of Trypanosoma rangeli strains isolated from Rhodnius ecuadoriensis in Peru, R. colombiensis in Colombia and R. pallescens in Panama, supports a co-evolutionary association between parasites and vectors.

    Science.gov (United States)

    Urrea, D A; Carranza, J C; Cuba, C A Cuba; Gurgel-Gonçalves, R; Guhl, F; Schofield, C J; Triana, O; Vallejo, G A

    2005-03-01

    We present data on the molecular characterisation of strains of Trypanosoma rangeli isolated from naturally infected Rhodnius ecuadoriensis in Peru, from Rhodnius colombiensis, Rhodnius pallescens and Rhodnius prolixus in Colombia, and from Rhodnius pallescens in Panama. Strain characterisation involved a duplex PCR with S35/S36/KP1L primers. Mini-exon gene analysis was also carried out using TrINT-1/TrINT-2 oligonucleotides. kDNA and mini-exon amplification indicated dimorphism within both DNA sequences: (i) KP1, KP2 and KP3 or (ii) KP2 and KP3 products for kDNA, and 380 bp or 340 bp products for the mini-exon. All T. rangeli strains isolated from R. prolixus presented KP1, KP2 and KP3 products with the 340 bp mini-exon product. By contrast, all T. rangeli strains isolated from R. ecuadoriensis, R. pallescens and R. colombiensis, presented profiles with KP2 and KP3 kDNA products and the 380 bp mini-exon product. Combined with other studies, these results provide evidence of co-evolution of T. rangeli strains associated with different Rhodnius species groups east and west of the Andean mountains.

  3. Alimentación y defecación en triatominos del género Rhodnius (Hemiptera: Reduviidae alimentados con sangre humana

    Directory of Open Access Journals (Sweden)

    E. Aldana

    2001-06-01

    Full Text Available Se estudió el comportamiento alimenticio y de defecación de Rhodnius prolixus Stal, 1859, R. robustus Larrousse, 1927, R. neivai Lent, 1953 y R. pictipes Stal, 1872 alimentados artificialmente con sangre humana en condiciones de laboratorio. La ninfa I de todas las especies no defecaron en la primera media hora después de haber iniciado la ingesta. R. pictipes no se acercó a picar en el alimentador artificial aunque si lo hizo cuando el alimento se ofreció directamente sobre el cuerpo humano. Las ninfas y adultos de R. prolixus mostraron índices de defecación (ID superiores a los correspondientes de las otras especies, y la ninfa III presentó el mayor ID=1.62. La mayoría de individuos de todos los estadíos de desarrollo aceptaron el alimento en un tiempo entre 0 y 3 min y se alimentaron en menos de 15 minutos.Feeding and defecaction behavior of Rhodnius prolixus Stal, 1859, R. robustus Larrousse, 1927, R. neivai Lent, 1953 and R. pictipes Stal, 1872, artificially fed on human blood, were studied under laboratory conditions. In all species, first instar nymphs did not defecate in the first 30 minutes after feeding. R. pictipes did not accept artificial feeding but fed directly on humans. Nymph and adult R. prolixus had a higher defecation index (DI than other species; third instar nymphs had the highest DI=1.62. In all instars, most individuals accepted the food in £ 3 minutes and finished feeding in less than 15 minutes.

  4. Novel adipokinetic hormones in the kissing bugs Rhodnius prolixus, Triatoma infestans, Dipetalogaster maxima and Panstrongylus megistrus

    Czech Academy of Sciences Publication Activity Database

    Marco, H. G.; Šimek, Petr; Clark, K. D.; Gäde, G.

    2013-01-01

    Roč. 41, MAR 10 (2013), s. 21-30 ISSN 0196-9781 R&D Projects: GA MZd(CZ) NT11513 Grant - others:National Research Foundation(ZA) IFR 2008071500048; National Research Foundation(ZA) FA 2007021300002 Institutional support: RVO:60077344 Keywords : insects * kissing bugs * reduviidae Subject RIV: ED - Physiology Impact factor: 2.614, year: 2013 http://www.sciencedirect.com/science/article/pii/S0196978112004433

  5. Application of phase-contrast X-ray microtomography to study the internal structures of Rhodium prolixus

    International Nuclear Information System (INIS)

    Almeida, Andre P. de; Soares, Jose; Barroso, Regina C.; Braz, Delson; Cardoso, Simone C.; Garcia, Eloi S.; Azambuja, Patricia; Gonzalez, Marcelo S.

    2011-01-01

    The PhC-SR-μCT is a nondestructive technique that allows the microanatomical investigations and 3D images reconstructions within a short time. This technique performed in blood sucker, Rhodnius prolixus - one of the most important primary vectors of of Trypanosoma cruzi, ethiologic agent of Chagas' disease in Latin America and also the most well-know studied insect in terms of both physiology and vector-parasite interactions. However, little is known about the development and structure of its internal organs. The aim of this work is to provide a non-invasive option for studying the internal structures of the main vector of Chagas' disease, which should help to answer important questions concerning anatomy, development, structure and plasticity of insect in general. Three-dimensional rendering images can provide a detailed knowledge of the interior of the insect, which is crucial for a better understanding of its function and evolution. (author)

  6. Application of phase-contrast X-ray microtomography to study the internal structures of Rhodium prolixus

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Andre P. de; Soares, Jose; Barroso, Regina C. [State University of Rio de Janeiro (UERJ), RJ (Brazil). Physics Institute; Braz, Delson, E-mail: delson@lin.ufrj.b [Federal University of Rio de Janeiro (COPPE/UFRJ), RJ (Brazil). Nuclear Engineering Program; Cardoso, Simone C., E-mail: simone@if.ufrj.b [Federal University of Rio de Janeiro (IF/UFRJ), RJ (Brazil). Physics Institute; Garcia, Eloi S.; Azambuja, Patricia [Oswaldo Cruz Institute (FIOCRUZ), Rio de Janeiro, RJ (Brazil). Lab. of Biochemistry and Physiology of Insects; Gonzalez, Marcelo S. [Federal University Fluminense (UFF), Niteroi, RJ (Brazil). Dept. of General Biology

    2011-07-01

    The PhC-SR-{mu}CT is a nondestructive technique that allows the microanatomical investigations and 3D images reconstructions within a short time. This technique performed in blood sucker, Rhodnius prolixus - one of the most important primary vectors of of Trypanosoma cruzi, ethiologic agent of Chagas' disease in Latin America and also the most well-know studied insect in terms of both physiology and vector-parasite interactions. However, little is known about the development and structure of its internal organs. The aim of this work is to provide a non-invasive option for studying the internal structures of the main vector of Chagas' disease, which should help to answer important questions concerning anatomy, development, structure and plasticity of insect in general. Three-dimensional rendering images can provide a detailed knowledge of the interior of the insect, which is crucial for a better understanding of its function and evolution. (author)

  7. Stahl et les âges de la vie

    Directory of Open Access Journals (Sweden)

    Sarah Carvallo

    2011-07-01

    Full Text Available La vieillesse constitue une pierre de touche pour toute théorie médicale : elle oblige à rendre raison de la temporalité à l’œuvre dans la vie. Aux yeux de Stahl, les iatromécaniciens méconnaissent la dimension temporelle de l’organisme ; en particulier, ils en ignorent la périodicité. Comprendre la vieillesse suppose donc la critique de la représentation linéaire du temps organique, que développe la mécanique et qui réduit le vivant au seul composé physique et chimique. Il reste alors à trouver la cause de la périodicité organique : sur ce point, Georg Ernst Stahl critique Thomas Sydenham, qui reconnaît certes la périodicité du vivant mais nie la possibilité d’une médecine étiologique. Pour sa part, le médecin de Halle cherche à rendre compte du vieillissement en lien avec les actions organiques fondamentales : le tonus, la circulation, l’excrétion, la sécrétion.

  8. Sodium pumps in the Malpighian tubule of Rhodnius sp.

    Directory of Open Access Journals (Sweden)

    CARUSO-NEVES CELSO

    2000-01-01

    Full Text Available Malpighian tubule of Rhodnius sp. express two sodium pumps: the classical ouabain-sensitive (Na+ + K+ATPase and an ouabain-insensitive, furosemide-sensitive Na+-ATPase. In insects, 5-hydroxitryptamine is a diuretic hormone released during meals. It inhibits the (Na+ + K+ATPase and Na+ -ATPase activities indicating that these enzymes are involved in fluid secretion. Furthermore, in Rhodnius neglectus, proximal cells of Malpighian tubule exposed to hyperosmotic medium, regulate their volume through a mechanism called regulatory volume increase. This regulatory response involves inhibition of the (Na+ + K+ATPase activity that could lead to accumulation of active osmotic solute inside the cell, influx of water and return to the normal cell volume. Adenosine, a compound produced in stress conditions, also inhibits the (Na+ + K+ATPase activity. Taken together these data indicate that (Na+ + K+ATPase is a target of the regulatory mechanisms of water and ions transport responsible for homeostasis in Rhodnius sp.

  9. 1 küsimus noorele juhile : Said just juhiks. Millest tuleks alustada? / Gert Stahl, Erki Kert, Madis Talmar ... [jt

    Index Scriptorium Estoniae

    2009-01-01

    Juhtimisküsimusele vastavad EASi rahvusvahelistumise divisjoni direktor, riskikapitali ettevõtte G.S.I. Ventures juhatuse esimees ning moefirma Bastion nõukogu esimees Gert Stahl, LHV juhatuse liige ja LHV ettevõtete nõustamise valdkonna juht Erki Kert, Tallinna Tehnikaülikooli tudeng ja mitmete üliõpilasprojektide juht Madis Talmar, filmitootmisfirma Alexandra Film produtsent Marianne Ostrat, ettevõtluskonsultant Liina Joller ning konsultatsioonifirma BDA Consulting juht Lo Rihvk

  10. Observations on the Domestic Ecology of Rhodnius ecuadoriensis (Triatominae

    Directory of Open Access Journals (Sweden)

    Abad-Franch F

    2002-01-01

    Full Text Available Rhodnius ecuadoriensis infests peridomiciles and colonises houses in rural southern Ecuador. Six out of 84 dwellings (7% surveyed in a rural village were infested (78 bugs/infested domicile; 279 bugs were collected in a single dwelling. Precipitin tests revealed R. ecuadoriensis fed on birds (65%, rodents (31%, marsupials (8%, and humans (15% - mixed bloodmeals detected in 37.5% of individual samples. Trypanosoma cruzi from opossums and rodents may thus be introduced into the domestic cycle. Wasp parasitoidism was detected in 6.5% of 995 R. ecuadoriensis eggs (only in peridomestic habitats. Control strategies should integrate insecticide spraying (indoors and peridomestic, better management of poultry, and housing improvements. A possible inefficacy of Malathion is reported.

  11. Chagas' disease in the Amazon Basin: V. Periurban palms as habitats of Rhodnius robustus and Rhodnius pictipes - triatomine vectors of Chagas' disease

    Directory of Open Access Journals (Sweden)

    M. A. Miles

    1983-12-01

    Full Text Available Trypanosoma cruzi infected Rhodnius robustus and/or Rhodnius pictipes were commonly found, in large numbers, in the Brazilian Amazonian palms Maximiliana regia ("inajá", Acrocomia sclerocarpa ("mucajá" and Orbignya speciosa ("babaçu". The common opossum, Didelphis marsupialis, was the animal most frequently associated with triatomine infested palms. R. pictipes, frequently light-attracted into houses from palm trees, was the probable source of an acute case of Chagas' disease in the vicinity of Belém. It is considered that triatomine infested palms are likely to cause some cases of acute Chagas' disease in the States of Amazonas and Rondônia. Possible control methods are suggested.Rhodnius robustus e/ou Rhodnius pictipes, infectados com Trypanosoma cruzi foram comumente encontrados, em grande numero, nas palmeiras Maximiliana regia (inaja, Acrocomia sclerocarpa (mucaja e Orbignya speciosa (babacu na Amazonia brasileira. O marsupial Didelphis marsupialis foi o animal encontrado mais frequentemente nas palmeiras associadas a alta prevalencia de triatomineos. R. pictipes que e atraido pela luz nas residencias de palmeiras vizinhas, provavelmente e a fonte de um caso agudo de doenca de Chagas nas vizinhancas de Belem. Sugere-se que as palmeiras albergando triatomineos poderiam ser relacionadas com infeccoes humanas de doenca de Chagas nos Estados de Amazonas e Rondonia. Sugere-se, tambem, possiveis metodos de controle.

  12. Silencing of RpATG6 impaired the yolk accumulation and the biogenesis of the yolk organelles in the insect vector R. prolixus.

    Directory of Open Access Journals (Sweden)

    Priscila H Vieira

    2018-05-01

    Full Text Available In oviparous animals, the egg yolk is synthesized by the mother in a major metabolic challenge, where the different yolk components are secreted to the hemolymph and delivered to the oocytes mostly by endocytosis. The yolk macromolecules are then stored in a wide range of endocytic-originated vesicles which are collectively referred to as yolk organelles and occupy most of the mature oocytes cytoplasm. After fertilization, the contents of these organelles are degraded in a regulated manner to supply the embryo cells with fundamental molecules for de novo synthesis. Yolk accumulation and its regulated degradation are therefore crucial for successful development, however, most of the molecular mechanisms involved in the biogenesis, sorting and degradation of targeted yolk organelles are still poorly understood. ATG6 is part of two PI3P-kinase complexes that can regulate the recruitment of the endocytic or the autophagy machineries. Here, we investigate the role of RpATG6 in the endocytosis of the yolk macromolecules and in the biogenesis of the yolk organelles in the insect vector Rhodnius prolixus. We found that vitellogenic females express high levels of RpATG6 in the ovaries, when compared to the levels detected in the midgut and fat body. RNAi silencing of RpATG6 resulted in yolk proteins accumulated in the vitellogenic hemolymph, as a consequence of poor uptake by the oocytes. Accordingly, the silenced oocytes are unviable, white (contrasting to the control pink oocytes, smaller (62% of the control oocyte volume and accumulate only 40% of the yolk proteins, 80% of the TAG and 50% of the polymer polyphosphate quantified in control oocytes. The cortex of silenced oocytes present atypical smaller vesicles indicating that the yolk organelles were not properly formed and/or sorted, which was supported by the lack of endocytic vesicles near the plasma membrane of silenced oocytes as seen by TEM. Altogether, we found that RpATG6 is central for the

  13. Literary Returns: HENRIETTE YVONNE STAHL or the Fate of an Exceptional Woman to the Backdrop of Dramatic History

    Directory of Open Access Journals (Sweden)

    Constanţa-Valentina MIHĂILĂ

    2013-01-01

    Full Text Available The history of the Romanian literature includes writers who, without being leading writers, have modern readers and success on the market. Henriette Yvonne Stahl crossed almost whole 20th century, with all his historical events, wrote nine novels, two volumes of short novels, a volume of poems and performed the translation of ten masterpieces from eight writers. Although she was native French speaker, the writer has created only in Romanian language and never ceased on being Romanian citizen. The men from her life, Ion Vinea and Petru Dumitriu, had in her an incentive of their talent and a formidable critic. The disease was the background of her existence, but this did not spare her from the communist prison experience. Without being enroll in some literary circle or some fancy literary orientation, without writing memories or being diarist, she spread her ego and her experiences throughout his entire opera, and she kept her aristocratic halo and her principles till the end of her life.

  14. Description and characterization of the melanic morphotype of Rhodnius nasutus Stål, 1859 (Hemiptera: Reduviidae: Triatominae

    Directory of Open Access Journals (Sweden)

    Fernando Braga Stehling Dias

    2014-10-01

    Full Text Available Introduction For the first time we provide the description of the melanic (dark morphotype of Rhodnius nasutus and determine the pattern of genetic inheritance for this characteristic. Methods Dark morph R. nasutus specimens were crossbred with standard (typically patterned R. nasutus. Results We present the first occurrence of the melanic morphotype in the genus Rhodnius. The crossbreeding results demonstrate that the inheritance pattern of this characteristic follows Mendel's simple laws of segregation and an independent assortment of alleles. Conclusions Phenotypic variation of R. nasutus reinforces the heterogeneity found in the Triatominae. Descriptions of new species in this subfamily require rigorous validation criteria.

  15. Influência da temperatura e umidade no desenvolvimento ninfal de Rhodnius robustus Influence of temperature and humidity on the nymphal development of Rhodnius robustus

    Directory of Open Access Journals (Sweden)

    Dayse da S Rocha

    2001-08-01

    Full Text Available OBJETIVO: Avaliar as diferenças significativas de desenvolvimento ninfal da espécie Rhodnius robustus Larrousse, 1927, submetida a diferentes condições de temperatura e umidade, que se encontra distribuída na região Norte do Brasil (Acre, Amazonas e Pará e na Colômbia, no Equador, no Peru e na Venezuela. MÉTODOS: Formaram-se três grupos de Rhodnius robustus, mantidos em diferentes condições de laboratório: 33/40 (33+/-1°C e 40+/-5% UR -- umidade relativa, 33/70 (33+/-1°C e 70+/-5% UR e 28/70 (28+/-1°C e 70+/-5% UR, para observar o período de incubação dos ovos, o desenvolvimento de cada estádio, os percentuais de mortalidade e os número de repastos realizados. RESULTADOS: O menor período médio de desenvolvimento ninfal foi observado no grupo 28/70 com as médias: 14,4; 17,3; 20,3; 22,8 e 40. O desenvolvimento embrionário apresentou diferenças significativas entre os tratamentos utilizados (pOBJECTIVE: To assess the significant differences in the nymphal development of the Rhodnius robustus Larrousse, 1927 under different temperatures and humidity conditions. This is a species found in the northern region of Brazil (states of Acre, Amazonas, and Pará, Colombia, Equator, Peru and Venezuela. METHODS: Three groups of triatominae were kept under the following laboratory conditions: 33/40 (33+1°C and 40+/-5% of relative humidity -- RH, 33/70 (33+/-1°C and 70+/-5% RH, and 28/70 (28+/-1°C and 70+/-5% RH. The incubation period of the eggs, developmental time of each stage, mortality percentage, number of bloodmeals, and the total amount of time from the egg hatching to adult ecdysis were observed. RESULTS: The shortest average time of nymphal development was observed in the 28/70 group, with following averages: 14.4, 17.3, 20.3, 22.8, and 40. Significant differences were observed in the embryonic development between the groups (p<0.01. For all groups, the number of bloodmeals had a gradual increase near the adult phase

  16. Genetic, cytogenetic and morphological trends in the evolution of the Rhodnius (Triatominae: Rhodniini) trans-Andean group.

    Science.gov (United States)

    Díaz, Sebastián; Panzera, Francisco; Jaramillo-O, Nicolás; Pérez, Ruben; Fernández, Rosina; Vallejo, Gustavo; Saldaña, Azael; Calzada, Jose E; Triana, Omar; Gómez-Palacio, Andrés

    2014-01-01

    The Rhodnius Pacific group is composed of three species: Rhodnius pallescens, R. colombiensis and R. ecuadoriensis, which are considered important vectors of trypanosomes (Trypanosoma cruzi and T. rangeli) infecting humans. This group is considered as a recent trans-Andean lineage derived from the widespread distributed sister taxa R. pictipes during the later uplift of northern Andes mountain range. The widest spread species R. pallescens may be a complex of two divergent lineages with different chromosomal attributes and a particular biogeographical distribution across Central America and Colombia with several southern populations in Colombia occupying the same sylvatic habitat as its sister species R. colombiensis. Although the taxonomy of Rhodnius Pacific group has been well studied, the unresolved phylogenetic and systematic issues are the target of this paper. Here we explore the molecular phylogeography of this species group analyzing two mitochondrial (ND4 and cyt b) and one nuclear (D2 region of ribosomal 28S gene) gene sequences. The molecular analyses suggest an early divergence of the species R. ecuadoriensis and R. colombiensis, followed by a recent expansion of R. pallescens lineages. The phylogenetic relationship between sympatric R. pallescens Colombian lineage and R. colombiensis was further explored using wing morphometry, DNA genome size measurements, and by analyzing chromosomal behavior of hybrids progeny obtained from experimental crosses. Our results suggest that the diversification of the two R. pallescens lineages was mainly influenced by biogeographical events such as (i) the emergence of the Panama Isthmus, while the origin and divergence of R. colombiensis was associated with (ii) the development of particular genetic and chromosomal features that act as isolation mechanisms from its sister species R. pallescens (Colombian lineage). These findings provide new insights into the evolution of the Rhodnius Pacific group and the underlying

  17. Resistance to starvation of Rhodnius neivai Lent, 1953 (Hemiptera: Reduviidae: Triatominae under experimental conditions

    Directory of Open Access Journals (Sweden)

    Daniel R Cabello

    2001-05-01

    Full Text Available The period of resistance to starvation and the loss of weight until death of Rhodnius neivai in all stages of development were studied. Work was based on experiments conducted under controlled laboratory conditions. One hundred specimens of each nymphal instar were observed: 50 were fed on chicken and 50 on rabbit. Adult females and males were kept together and fed on each host. All bugs were weighed weekly until death. Laid eggs were collected weekly and observed during five weeks to obtain hatchability. Resistance to starvation was similar with both hosts and increased with the evolutionary stage, excepting the 5th nymphal instar and adults. With both hosts, loss of weight was abrupt in the first week and steady in the following weeks. In adults, on the first weeks after eating, there was little or no mortality, after which mortality increased rapidly with the starving time. Reproductive output was higher in the bugs fed on rabbit. R. neivai is among the least resistant triatomine species.

  18. Alpinia Essential Oils and Their Major Components against Rhodnius nasutus, a Vector of Chagas Disease

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    Thamiris de A. de Souza

    2018-01-01

    Full Text Available Species of the genus Alpinia are widely used by the population and have many described biological activities, including activity against insects. In this paper, we describe the bioactivity of the essential oil of two species of Alpinia genus, A. zerumbet and A. vittata, against Rhodnius nasutus, a vector of Chagas disease. The essential oils of these two species were obtained by hydrodistillation and analyzed by GC-MS. The main constituent of A. zerumbet essential oil (OLALPZER was terpinen-4-ol, which represented 19.7% of the total components identified. In the essential oil of A. vittata (OLALPVIT the monoterpene β-pinene (35.3% was the main constituent. The essential oils and their main constituents were topically applied on R. nasutus fifth-instar nymphs. In the first 10 min of application, OLALPVIT and OLALPZER at 125 μg/mL provoked 73.3% and 83.3% of mortality, respectively. Terpinen-4-ol at 25 μg/mL and β-pinene at 44 μg/mL provoked 100% of mortality. The monitoring of resistant insects showed that both essential oils exhibited antifeedant activity. These results suggest the potential use of A. zerumbet and A. vittata essential oils and their major constituents to control R. nasutus population.

  19. Phenotypic variability of Rhodnius ecuadoriensis populations at the Ecuadorian central and southern Andean region.

    Science.gov (United States)

    Villacís, Anita G; Grijalva, Mario J; Catalá, Silvia S

    2010-11-01

    Rhodnius ecuadoriensis is an important vector of Chagas disease in Ecuador. Whereas only sylvatic and peridomestic populations are common in Manabi province, this species occupies domestic, peridomestic, and sylvatic habitats in Loja province where high reinfestation of houses was observed. To explore the existence of phenetic changes linked to the domiciliation of the species, this study set out to analyze the wing and antennal phenotypes of R. ecuadoriensis in these two provinces where the vector presents different affinity for domestic habitats. The antennal phenotype and the wing size and shape distinguish the two geographical populations of R. ecuadoriensis. In Manabí, sylvatic and peridomestic specimens were very similar. In Loja, sylvatic and nonsylvatic (domestic and peridomestic) populations showed distinctive characteristics. Remarkable sexual dimorphism of wing and antenna, exclusive of domestic specimens, and high metric disparity in the wing shape of the domestic females point out the existence of a particular situation in this habitat. The results of this phenotypic analysis and previous evidence of behavioral differences support the hypothesis of disruptive selection acting upon R. ecuadoriensis populations.

  20. Presence of Rhodnius ecuadoriensis in sylvatic habitats in the southern highlands (Loja Province) of Ecuador.

    Science.gov (United States)

    Grijalva, M J; Villacis, A G

    2009-05-01

    The main vectors of Chagas disease in Ecuador are Triatoma dimidiata and Rhodnius ecuadoriensis. The latter species occupies domestic and peridomestic habitats, as well as sylvatic ecotopes--particularly associated with Phytelephas aequatorialis palm trees--in the western coastal region of Ecuador. In the southern highlands, however, such palm tree habitats are uncommon, and sylvatic populations of R. ecuadoriensis have not previously been reported to date. This study was carried out in five rural communities in Loja Province in southern Ecuador, where manual triatomine searches were conducted in various sylvatic habitats. A total of 81 squirrel nests (Sciurus stramineus) and > 200 bird nests and other habitats were searched. One hundred three R. ecuadoriensis individuals were found in 11 squirrel nests (infestation index = 13.6%, density = 2 bugs per nest searched, crowding = 9.5 bugs per infested nest, colonization index = 72.7% of infested nests with nymphs). No triatomines were found in bird nests or other sylvatic habitats. The presence of sylvatic R. ecuadoriensis in the southern highlands of Ecuador has important implications for the long-term control of Chagas disease in the region because of the possibility of reinfestation of dwellings after insecticide-based control interventions.

  1. A Deep Insight into the Sialome of Rhodnius neglectus, a Vector of Chagas Disease.

    Directory of Open Access Journals (Sweden)

    Paula Beatriz Santiago

    2016-04-01

    Full Text Available Triatomines are hematophagous insects that act as vectors of Chagas disease. Rhodnius neglectus is one of these kissing bugs found, contributing to the transmission of this American trypanosomiasis. The saliva of hematophagous arthropods contains bioactive molecules responsible for counteracting host haemostatic, inflammatory, and immune responses.Next generation sequencing and mass spectrometry-based protein identification were performed to investigate the content of triatomine R. neglectus saliva. We deposited 4,230 coding DNA sequences (CDS in GenBank. A set of 636 CDS of proteins of putative secretory nature was extracted from the assembled reads, 73 of them confirmed by proteomic analysis. The sialome of R. neglectus was characterized and serine protease transcripts detected. The presence of ubiquitous protein families was revealed, including lipocalins, serine protease inhibitors, and antigen-5. Metalloproteases, disintegrins, and odorant binding protein families were less abundant.The data presented improve our understanding of hematophagous arthropod sialomes, and aid in understanding hematophagy and the complex interplay among vectors and their vertebrate hosts.

  2. The effect of Ageratum fastigiatum extract on Rhodnius nasutus, vector of Chagas disease

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    Bethânia A. Avelar-Freitas

    2013-04-01

    Full Text Available Control of Chagas disease is based on insecticide spraying in domiciles in order to exterminate triatomine populations. However, since the vectors differ in susceptibility to currently used insecticides, the screening of the toxic potential of Brazilian flora may identify new molecules lethal to triatomines. This study evaluated the toxicity of ethanolic extract of Ageratum fastigiatum (Gardner R.M. King & H. Rob., Asteraceae, on Rhodnius nasutus, a known vector of Chagas disease. Ethanolic extracts of the aerial parts of A. fastigiatum were prepared at 25 and 50 mg/mL concentrations, and 5 µL was applied to fifth-instar nymphs of R. nasutus (n=30. Controls included nymphs that were treated with 5 µL ethanol (n=30 or left untreated (n=30. The percentage of dead insects in each group was observed at 24, 48, 72, 96 and 120 h after application. The extracts of A. fastigiatum showed a mortality rate of about 37% and 77% after 120 h, at concentrations of 25 and 50 mg/mL, respectively. In control groups, the mortality rate remained under 7%. The extract of A. fastigiatum contains a coumarin, a molecule with recognized toxicity in insects, and which may be responsible for killing the triatomines.

  3. First report of Rhodnius stali (Hemiptera, Reduviidae, Triatominae in the State of Acre and in the Brazilian Amazon

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    Dionatas Ulises de Oliveira Meneguetti

    2016-06-01

    Full Text Available Abstract: INTRODUCTION: This paper reports, for the first time, the presence of Rhodnius stali in the state of Acre and in the Brazilian Amazon. METHODS: Specimens of R. stali were collected by the Federal University of Acre in Rio Branco. RESULTS: The number of Triatominae species in the State of Acre increased from five to six. This was also the first report of R. stali in the Brazilian Amazon. CONCLUSIONS: The occurrence of R. stali is worrisome, since this species has been found naturally infected by Trypanosoma cruzi and there has been evidence of its domiciliation capabilities.

  4. Biocide activity of Annona coriacea seeds extract on Rhodnius neglectus (Hemiptera: Reduviidae

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    Ângela Pinheiro Carneiro

    2013-03-01

    Full Text Available The use of synthetic insecticides for insect control may lead to different kind of problems, such as vector resistance to insecticides. To avoid these problems, a new research area to study botanical products as possible disease vectors controls, has become a feasible alternative. The purpose of this research was to evaluate the biocide activity of the ethanol extract of seeds of Annona coriacea on Rhodnius neglectus (Chagas disease vector nymphs and adults. For this, different concentrations extracts were evaluated: 25, 50, 100 and 200mg/ mL, and water in DMSO (20% was used as control. The experimental design was completely randomized and we conducted the bioassay with nymphs and adults, with 10 nymphs and 10 adults (five males and five females per treatment. Extract action was evaluated in both bioassays, in order to identify possible effects of mortality and life cycle interruption of nymphs and adults during a 28-day-period. The results obtained showed that the extract of A. coriacea was able to disrupt the development of nymphs and adults of R. neglectus, with a mortality rate of more than 90%, 36% and 100%, at the highest concentrations, respectively. There was also molting inhibition in nymphs, lower reproductive capacity in females, feeding deterrence and morphological changes in nymphs and adults. We concluded that the extract of A. coriacea has insecticide action on nymphs and adults of R. neglectus.La enfermedad de Chagas se convirtió en un problema de salud debido a su importancia epidemiológica, es producida por el protista Trypanosoma cruzi, cuyos insectos vectores son del género Triatoma y Panstrongylus. El objetivo de este estudio fue evaluar la actividad biocida del extracto de Annona coriacea en las ninfas de Rhodnius neglectus y en sus adultos. Se evaluaron 14 concentraciones de 25, 50, 100 y 200mg/ml del extracto etanólico, así como el control, en este caso agua de DMSO (20%. Se utilizo un diseño completamente

  5. Estudo sobre a utilização de Rhodnius neglectus para xenodiagnósticos realizados em marsupiais (Didelphis The utilization of Rhodnius neglectus in xenodiagnosis: a study performed on opossums

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    Oswaldo Paulo Forattini

    1976-12-01

    Full Text Available Em marsupiais (Didelphis, portadores de infecção natural pelo T. cruzi, procurou-se levar a efeito xenodiagnósticos com o emprego de ninfas de Rhodnius neglectus e de Triatoma infestans e através do exame periódico de lotes formados por cinco insetos. Pôde-se observar o melhor rendimento por parte do exame do intestino posterior, mediante dissecção. O tempo ótimo foi situado no intervalo correspondente a 15 e 20 dias, e a eficiência de R. neglectus foi superior. Esse resultado, aliado à facilidade de sua manutenção em laboratório, sugere a utilização rotineira desse triatomíneo para fins de xenodiagnóstico.Third and fourth instars of Rhodnius neglectus and Triatoma infestans were fed on wild opossums (Didelphis with natural infeccions by Trypanosoma cruzi and, examined at regular 3.5 days intervals. Best results were obtained with rectum examinations and the infeccion was more easily detected from the 15th to the 20th days. R. neglectus showed better performance than T. infestans and so its utilisation in the xenodiagnosis technique is suggested.

  6. Ecological factors related to the widespread distribution of sylvatic Rhodnius ecuadoriensis populations in southern Ecuador

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    Grijalva Mario J

    2012-01-01

    Full Text Available Abstract Background Chagas disease transmission risk is a function of the presence of triatomines in domestic habitats. Rhodnius ecuadoriensis is one of the main vectors implicated in transmission of Trypanosoma cruzi in Ecuador. This triatomine species is present in domestic, peridomestic and sylvatic habitats in the country. To determine the distribution of sylvatic populations of R. ecuadoriensis and the factors related to this distribution, triatomine searches were conducted between 2005 and 2009 in southern Ecuador. Methods Manual triatomine searches were conducted by skilled bug collectors in 23 communities. Sylvatic searched sites were selected by a directed sampling, where microhabitats were selected by the searchers and b random sampling, where sampling points where randomly generated. Domiciliary triatomine searches were conducted using the one man-hour method. Natural trypanosome infection was determined by microscopic examination and PCR. Generalized linear models were used to test the effect of environmental factors on the presence of sylvatic triatomines. Results In total, 1,923 sylvatic individuals were collected representing a sampling effort of 751 man-hours. Collected sylvatic triatomines were associated with mammal and bird nests. The 1,219 sampled nests presented an infestation index of 11.9%, a crowding of 13 bugs per infested nest, and a colonization of 80% of the nests. Triatomine abundance was significantly higher in squirrel (Sciurus stramineus nests located above five meters from ground level and close to the houses. In addition, 8.5% of the 820 examined houses in the same localities were infested with triatomines. There was a significant correlation between R. ecuadoriensis infestation rates found in sylvatic and synanthropic environments within communities (p = 0.012. Parasitological analysis revealed that 64.7% and 15.7% of the sylvatic bugs examined (n = 300 were infected with Trypanosoma cruzi and T. rangeli

  7. Ecological factors related to the widespread distribution of sylvatic Rhodnius ecuadoriensis populations in southern Ecuador

    Science.gov (United States)

    2012-01-01

    Background Chagas disease transmission risk is a function of the presence of triatomines in domestic habitats. Rhodnius ecuadoriensis is one of the main vectors implicated in transmission of Trypanosoma cruzi in Ecuador. This triatomine species is present in domestic, peridomestic and sylvatic habitats in the country. To determine the distribution of sylvatic populations of R. ecuadoriensis and the factors related to this distribution, triatomine searches were conducted between 2005 and 2009 in southern Ecuador. Methods Manual triatomine searches were conducted by skilled bug collectors in 23 communities. Sylvatic searched sites were selected by a) directed sampling, where microhabitats were selected by the searchers and b) random sampling, where sampling points where randomly generated. Domiciliary triatomine searches were conducted using the one man-hour method. Natural trypanosome infection was determined by microscopic examination and PCR. Generalized linear models were used to test the effect of environmental factors on the presence of sylvatic triatomines. Results In total, 1,923 sylvatic individuals were collected representing a sampling effort of 751 man-hours. Collected sylvatic triatomines were associated with mammal and bird nests. The 1,219 sampled nests presented an infestation index of 11.9%, a crowding of 13 bugs per infested nest, and a colonization of 80% of the nests. Triatomine abundance was significantly higher in squirrel (Sciurus stramineus) nests located above five meters from ground level and close to the houses. In addition, 8.5% of the 820 examined houses in the same localities were infested with triatomines. There was a significant correlation between R. ecuadoriensis infestation rates found in sylvatic and synanthropic environments within communities (p = 0.012). Parasitological analysis revealed that 64.7% and 15.7% of the sylvatic bugs examined (n = 300) were infected with Trypanosoma cruzi and T. rangeli respectively, and 8% of the

  8. Comportamiento de Rhodnius robustus Larousse, 1927 (Hemiptera, Reduviidae durante su alimentación en condiciones de laboratorio

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    Camilo Rubio

    2013-06-01

    Full Text Available Introducción. A pesar del control de los insectos domiciliados, se siguen presentando casos de enfermedad de Chagas con la participación en la transmisión de especies peridomiciliarias y selváticas,una de las cuales es Rhodnius robustus, especie reportada con infecciones naturales de Trypanosoma cruzi y T. rangeli. Objetivo. Describir el comportamiento de R. robustus durante su alimentación en condiciones delaboratorio.Materiales y métodos. En cada estadio de desarrollo de R. robustus se analizó el tiempo promedio para alcanzar la repleción, número promedio de deyecciones, porcentaje de individuos que defecan durante la comida y ganancia de peso después de la alimentación. Resultados. Rhodnius robustus tardó entre 19:26 y 44:55 (minutos:segundos en alimentarse arepleción; los insectos defecaron en todos sus diferentes estadios durante la alimentación. El porcentaje de individuos que defecan durante la alimentación varía de 13,3 % a 93,3 %. Por otro lado, el consumo promedio de sangre en el quinto estadio, 337,19 mg, duplica la cantidad ingerida por los adultos, 161,25 mg. Conclusiones. En todos los estadios de R. robustus hay defecación durante la alimentación, factor que favorece su competencia vectorial. Sin embargo, el tiempo para la primera deyección, el porcentaje dedeyecciones y los individuos que defecan durante la comida, así como la cantidad de sangre ingerida, varían entre los estadios, lo cual indica que el comportamiento alimenticio está mediado por variables dependientes de la edad/estadio.   http://dx.doi.org/10.7705/biomedica.v33i2.743

  9. Heinrich Stahli ja Johannes Gutslaffi Uue Testamendi tõlke kõrvutus / An Attempt at the Comparison of the Translations of the New Testament by Heinrich Stahl und Johannes Gutslaff

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    Kristiina Ross

    2012-06-01

    Full Text Available The aim of the article is to compare two 17th century translations of the New Testament: the translation by Heinrich Stahl (1638 and the translation by Johannes Gutslaff (1641–1656. Relying on the model of description presented by Torop (1989 and Torop and Osimo (2010, the translations are described by three aspects (1 linguistic, (2 functional, (3 that of the translator`s position within three different time perspectives: achronic, synchronic and diachronic. Within the achronic perspective, the two translations seem to be quite different in all three aspects. In the case of Stahl´s translation, the original text was Luther´s German translation and the target language was the North-Estonian vernacular. Different parts of the Bible had probably been translated by different persons and Stahl collected them, publishing them in a volume of his church manual. Gutslaff, on the other hand, translated the text himself using the original Greek version. His target language was the South-Estonian vernacular but his work was never published. Within the diachronic perspective, the differences disappear and the two translations seem to be quite similar. From today`s point of view both tr anslations are linguistically archaic and have no functional value except as object s of scientific research. Synchronic description is the most complicated one. The article tries to put to the test the possibilities of describing old translations from the point of view of their translation method. Very few examples of the Estonian language of the 17th century have been preserved, most are translations from German written down by German pastors. In addition to that, researchers know almost nothing about the Estonian language spoken by native speaker s of the time. As a re sult of this, it is hard to evaluate the linguistic status of many constructions and idioms used by the translators. This in turn makes it difficult to evaluate the stylistic intentions of the translator

  10. Effects of environmental temperature on life tables of Rhodnius neivai Lent, 1953 (Hemiptera: Reduviidae under experimental conditions

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    Daniel R Cabello

    1999-09-01

    Full Text Available Changes in life tables of Rhodnius neivai due to variations of environmental temperature were studied, based on nine cohorts. Three cohorts were kept at 22°C, three at 27°C and three at 32°C. Cohorts were censused daily during nymphal instars and weekly in adults. Nine complete horizontal life tables were built. A high negative correlation between temperature and age at first laying was registered (r=-0,84. Age at maximum reproduction was significantly lower at 32°C. Average number of eggs/female/week and total eggs/female on its life time were significantly lower at 22°C. Total number of egg by cohort and total number of reproductive weeks were significantly higher at 27°C. At 32°C, generational time was significantly lower. At 27°C net reproductive rate and total reproductive value were significantly higher. At 22°C, intrinsic growth, finite growth and finite birth rates were significantly lower. At 22°C, death instantaneous rate was significantly higher.

  11. Trypanosoma cruzi-infected Panstrongylus geniculatus and Rhodnius robustus adults invade households in the Tropics of Cochabamba region of Bolivia.

    Science.gov (United States)

    Rojas-Cortez, Mirko; Pinazo, Maria-Jesus; Garcia, Lineth; Arteaga, Mery; Uriona, Liliana; Gamboa, Seyla; Mejía, Carolina; Lozano, Daniel; Gascon, Joaquim; Torrico, Faustino; Monteiro, Fernando A

    2016-03-16

    There are hardly any data available on the relationships between the parasite and the vector or regarding potential reservoirs involved in the natural transmission cycle of Trypanosoma cruzi in the Tropics of Cochabamba, Bolivia. Local families from communities were responsible for the capture of triatomine specimens, following a strategic methodology based on entomological surveillance with community participation developed by the National Chagas Programme of the Ministry of Health of Bolivia. We describe the collection of adult Panstrongylus geniculatus and Rhodnius robustus naturally infected with Trypanosoma cruzi from houses and from the hospital of Villa Tunari municipality. The flagellates found in the digestive tract of P. geniculatus belong to genetic lineages or DTUs TcI and TcIII, whereas only lineage DTU TcI was found in R. robustus. The detection of these vectors infected with T. cruzi reveals the vulnerability of local communities. The results presented here highlight the risk of Chagas disease transmission in a region previously thought not to be endemic, indicating that the Tropics of Cochabamba should be placed under permanent entomological and epidemiological surveillance.

  12. The Triatomines of Northern Peru, with Emphasis on the Ecology and Infection by Trypanosomes of Rhodnius ecuadoriensis (Triatominae

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    Cuba Cuba César A

    2002-01-01

    Full Text Available Information on the distribution and synanthropic behaviour of triatomines is essential for Chagas disease vector control. This work summarises such information from northern Peru, and presents new data on Rhodnius ecuadoriensis - an important local vector infesting 10-35% of dwellings in some zones. Three species are strongly synanthropic and may be suitable targets for chemical control of domestic/peridomestic bug populations. Panstrongylus herreri, the main domestic vector in the area, is probably present in sylvatic ecotopes in the Marañón river system. R. ecuadoriensis and Triatoma dimidiata seem exclusively domestic; biogeographical and ecological data suggest they might have spread in association with humans in northern Peru. Confirmation of this hypothesis would result in a local eradication strategy being recommended. Presence of trypanosome natural infection was assessed in 257 R. ecuadoriensis; Trypanosoma rangeli was detected in 4% of bugs. Six further triatomine species are potential disease vectors in the region (T. carrioni, P. chinai, P. rufotuberculatus, P. geniculatus, R. pictipes, and R. robustus, whilst Eratyrus mucronatus, E. cuspidatus, Cavernicola pilosa, Hermanlentia matsunoi, and Belminus peruvianus have little or no epidemiological significance. A strong community-based entomological surveillance system and collaboration with Ecuadorian public health authorities and researchers are recommended.

  13. 2b-RAD genotyping for population genomic studies of Chagas disease vectors: Rhodnius ecuadoriensis in Ecuador.

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    Luis E Hernandez-Castro

    2017-07-01

    Full Text Available Rhodnius ecuadoriensis is the main triatomine vector of Chagas disease, American trypanosomiasis, in Southern Ecuador and Northern Peru. Genomic approaches and next generation sequencing technologies have become powerful tools for investigating population diversity and structure which is a key consideration for vector control. Here we assess the effectiveness of three different 2b restriction site-associated DNA (2b-RAD genotyping strategies in R. ecuadoriensis to provide sufficient genomic resolution to tease apart microevolutionary processes and undertake some pilot population genomic analyses.The 2b-RAD protocol was carried out in-house at a non-specialized laboratory using 20 R. ecuadoriensis adults collected from the central coast and southern Andean region of Ecuador, from June 2006 to July 2013. 2b-RAD sequencing data was performed on an Illumina MiSeq instrument and analyzed with the STACKS de novo pipeline for loci assembly and Single Nucleotide Polymorphism (SNP discovery. Preliminary population genomic analyses (global AMOVA and Bayesian clustering were implemented. Our results showed that the 2b-RAD genotyping protocol is effective for R. ecuadoriensis and likely for other triatomine species. However, only BcgI and CspCI restriction enzymes provided a number of markers suitable for population genomic analysis at the read depth we generated. Our preliminary genomic analyses detected a signal of genetic structuring across the study area.Our findings suggest that 2b-RAD genotyping is both a cost effective and methodologically simple approach for generating high resolution genomic data for Chagas disease vectors with the power to distinguish between different vector populations at epidemiologically relevant scales. As such, 2b-RAD represents a powerful tool in the hands of medical entomologists with limited access to specialized molecular biological equipment.

  14. Pioneer study of population genetics of Rhodnius ecuadoriensis (Hemiptera: Reduviidae) from the central coastand southern Andean regions of Ecuador.

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    Villacís, Anita G; Marcet, Paula L; Yumiseva, César A; Dotson, Ellen M; Tibayrenc, Michel; Brenière, Simone Frédérique; Grijalva, Mario J

    2017-09-01

    Effective control of Chagas disease vector populations requires a good understanding of the epidemiological components, including a reliable analysis of the genetic structure of vector populations. Rhodnius ecuadoriensis is the most widespread vector of Chagas disease in Ecuador, occupying domestic, peridomestic and sylvatic habitats. It is widely distributed in the central coast and southern highlands regions of Ecuador, two very different regions in terms of bio-geographical characteristics. To evaluate the genetic relationship among R. ecuadoriensis populations in these two regions, we analyzed genetic variability at two microsatellite loci for 326 specimens (n=122 in Manabí and n=204 in Loja) and the mitochondrial cytochrome b gene (Cyt b) sequences for 174 individuals collected in the two provinces (n=73 and=101 in Manabí and Loja respectively). The individual samples were grouped in populations according to their community of origin. A few populations presented positive F IS, possible due to Wahlund effect. Significant pairwise differentiation was detected between populations within each province for both genetic markers, and the isolation by distance model was significant for these populations. Microsatellite markers showed significant genetic differentiation between the populations of the two provinces. The partial sequences of the Cyt b gene (578bp) identified a total of 34 haplotypes among 174 specimens sequenced, which translated into high haplotype diversity (Hd=0.929). The haplotype distribution differed among provinces (significant Fisher's exact test). Overall, the genetic differentiation of R. ecuadoriensis between provinces detected in this study is consistent with the biological and phenotypic differences previously observed between Manabí and Loja populations. The current phylogenetic analysis evidenced the monophyly of the populations of R. ecuadoriensis within the R. pallescens species complex; R. pallescens and R. colombiensis were more

  15. [Development of Rhodnius pictipes Stal, 1872 fed on mice and through a silicone membrane (Hemiptera, Reduviidae, Triatominae)].

    Science.gov (United States)

    Rocha, D da S; da Fonseca, A H; Costa, F A; Jurberg, J; Galvão, C

    1997-01-01

    Rhodnius pictipes (Hemiptera, Reduviidae) from Serra Norte, State of Pará, Brazil, acclimatized in an insectary at the Laboratório Nacional e Internacional de Referência em Taxonomia de Triatomíneos, Departamento de Entomologia, Instituto Oswaldo Cruz, were fed through a silicone membrane. In order to know the viability and the efficiency of this membrane compared with insects fed on mice, the number of bloodmeals taken, period of development of the five nymphal instars, longevity of adults, average amount of blood intake in each meal and percent of mortality were observed. A total of 310 insects, were used, comprising 50 nymphs of each instar, as well as 30 male and 30 female adults. Insects fed artificially had reduced minimal and maximal periods of development than the group fed on mice. The largest relative increase of body weight was observed in the 2nd instar followed by the 1st, and the amount of blood ingested increased during the development, to the 5th instar for both groups. There were no significant differences between the groups fed artificially and in vivo according to Tukey's test for p > 0.05. The percent of mortality in the 1st instar was 18% for artificially fed and 16% for the group fed on mice; these percentages decreased as insects developed until the 4th instar, without mortality, returning to increase in the 5th instar. R. pictipes was shown to be easily adaptable to artificial feeding, and could be considered as an important and viable experimental model.

  16. 2b-RAD genotyping for population genomic studies of Chagas disease vectors: Rhodnius ecuadoriensis in Ecuador.

    Science.gov (United States)

    Hernandez-Castro, Luis E; Paterno, Marta; Villacís, Anita G; Andersson, Björn; Costales, Jaime A; De Noia, Michele; Ocaña-Mayorga, Sofía; Yumiseva, Cesar A; Grijalva, Mario J; Llewellyn, Martin S

    2017-07-01

    Rhodnius ecuadoriensis is the main triatomine vector of Chagas disease, American trypanosomiasis, in Southern Ecuador and Northern Peru. Genomic approaches and next generation sequencing technologies have become powerful tools for investigating population diversity and structure which is a key consideration for vector control. Here we assess the effectiveness of three different 2b restriction site-associated DNA (2b-RAD) genotyping strategies in R. ecuadoriensis to provide sufficient genomic resolution to tease apart microevolutionary processes and undertake some pilot population genomic analyses. The 2b-RAD protocol was carried out in-house at a non-specialized laboratory using 20 R. ecuadoriensis adults collected from the central coast and southern Andean region of Ecuador, from June 2006 to July 2013. 2b-RAD sequencing data was performed on an Illumina MiSeq instrument and analyzed with the STACKS de novo pipeline for loci assembly and Single Nucleotide Polymorphism (SNP) discovery. Preliminary population genomic analyses (global AMOVA and Bayesian clustering) were implemented. Our results showed that the 2b-RAD genotyping protocol is effective for R. ecuadoriensis and likely for other triatomine species. However, only BcgI and CspCI restriction enzymes provided a number of markers suitable for population genomic analysis at the read depth we generated. Our preliminary genomic analyses detected a signal of genetic structuring across the study area. Our findings suggest that 2b-RAD genotyping is both a cost effective and methodologically simple approach for generating high resolution genomic data for Chagas disease vectors with the power to distinguish between different vector populations at epidemiologically relevant scales. As such, 2b-RAD represents a powerful tool in the hands of medical entomologists with limited access to specialized molecular biological equipment.

  17. COLONIZATION OF PALM TREES BY Rhodnius neglectus AND HOUSEHOLD AND INVASION IN AN URBAN AREA, ARAÇATUBA, SÃO PAULO STATE, BRAZIL

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    Vera Lúcia Cortiço Corrêa Rodrigues

    2014-06-01

    Full Text Available The objective of this study is to report on the colonization of palm trees by Rhodnius neglectus, its invasion in an urban area, in Araçatuba - São Paulo, and the control and surveillance measures that have been put in place. Domiciliary triatomine searches occurred in apartments upon the inhabitants' notification. The collected insects were identified and examined for natural infection and food sources with a precipitin test. To search the palm trees, tarps were used to cover the floor, and a “Munck” truck equipped with a tree-pruning device was utilized. Chemical control was performed with the utilization of a manual compression. In 2009, 81 specimens of Rhodnius neglectus were collected from the domiciles by the population. The precipitin test revealed a presence of human blood in 2.7% of the samples. Entomological studies were carried out in these domiciles and in those located within a radius of 200 meters. The search performed in the palm trees resulted in the capture of 882 specimens of triatomines, negative for tripanosomatids. Mechanical and chemical controls were carried out. New searches conducted in the palm trees in the same year resulted in the capture of six specimens. The mechanical and chemical controls of the palm trees, together with the population's work, proved to be effective, therefore preventing these insects' colonization of the city's domiciles.

  18. Diversity of anti-haemostatic proteins in the salivary glands of Rhodnius species transmitters of Chagas disease in the greater Amazon.

    Science.gov (United States)

    Bussacos, Ana C M; Nakayasu, Ernesto S; Hecht, Mariana M; Parente, Juliana A; Soares, Célia M A; Teixeira, Antônio R L; Almeida, Igor C

    2011-08-24

    The triatomines in the tribe Rhodniini are the main vectors of the Trypanosoma cruzi to humans in recent outbreaks of acute Chagas disease in the Amazon. These insects dwelling in palm trees do not colonize the human domicile. Their success to transmit the infection relies partially on the efficacy of their salivary gland apparatuses. Here we show the transcriptome of the Rhodnius brethesi and Rhodnius robustus salivary glands, comprising 56 and 122 clusters, respectively. Approximately one third of these clusters are described for the first time. The LC-MS/MS analysis identified 123 and 111 proteins in R. brethesi and R. robustus sialome, respectively. Noteworthy, lipocalin platelet aggregation inhibitors, inositol polyphosphate 5-phosphatases, and Kazal domain proteins, which are essential for the insect's successful acquisition of blood meals, were found in our analysis. Moreover, glutathione S transferase and antigen-5, which play roles in the insect's defense and resistance against insecticide, were also observed. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Sensibilidad de diferentes especies de Rhodnius (Hemiptera, Reduviidae, Triatominae a una cepa brasileña de Trypanosoma rangeli (SC58/KP1-

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    Daniella Barreto-Santana

    2015-03-01

    Materiales y métodos. Se seleccionaron treinta ninfas de cada especie después de xenodiagnóstico artificial en sangre infectada con T. rangeli. Se examinaron periódicamente muestras de heces y hemolinfa. Los insectos con hemolinfas infectadas fueron alimentados en ratones a fin de comprobar la transmisión por picadura y posteriormente disecados para confirmar la infección de las glándulas salivales. Resultados. En Rhodnius pictipes se encontró un mayor porcentaje de infección intestinal que en las otras especies. Se detectaron epimastigotes y tripomastigotes en la hemolinfa de las cuatro especies, y se encontró que el parasitismo fue menor en las especies del linaje R. robustus. Rhodnius robustus y R. neglectus no transmitían T. rangeli a ratones por picadura: después de la disección, sus glándulas no estaban infectadas. Solo un espécimen de R. nasutus y dos de R. pictipes transmitieron el parásito por la picadura. La tasa de infección glandular fue de 16 % para R. pictipes y de 4 % para R. nasutus. Conclusiones. La capacidad infecciosa (hemolinfática, intestinal y glandular y la transmisión de T. rangeli (SC-58/KP1- fueron mayores y más eficientes en R. pictipes. Estos resultados refuerzan la hipótesis de que estos triatominos actúan como filtros biológicos en la transmisión de T. rangeli.

  20. Steel or aluminium; Stahl oder Alu

    Energy Technology Data Exchange (ETDEWEB)

    Riedel, Anja

    2012-11-01

    This is a market survey of mounting racks for PV units. It contains 20 more products than the 2011 survey, of which twelve are newcomers to the market. Some manufacturers were able to cut the cost in accordance with the degression. The market survey shows that 120 - 130 Euros per kWh can be viewed as realistic.

  1. Ecological aspects of Rhodnius nasutus Stål, 1859 (Hemiptera: Reduviidae: Triatominae in palms of the Chapada do Araripe in Ceará, Brazil

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    Fernando Braga Stehling Dias

    2008-12-01

    Full Text Available The aim of this work is to present aspects related to the ecology of Rhodnius nasutus Stål, 1859 in palms from Chapada do Araripe in Ceará, Brazil. The following five species of palms were investigated: babaçu (Attalea speciosa, buriti (Mauritia flexuosa, carnaúba (Copernicia prunifera, catolé (Syagrus oleracea and macaúba-barriguda (Acrocomia intumescens. Fifth palms were dissected (10 specimens for each species. The overall infestation index was 86%, with a total of 521 triatomines collected. The Trypanosoma cruzi Chagas, 1909 Index was 16.8% and two insects presented mixed infection with Trypanosoma rangeli Tejera, 1920. A precipitin test showed that R. nasutus from palms of Chapada do Araripe are associated with opossum and bird although other possible bloodmeals were observed. Our results showing a high index of infestation of the palms as well as T. cruzi infection, the association of R. nasutus with the most diverse species of palms and proximity of these palms to houses demonstrate the importance of this area for sylvatic T. cruzi transmission and suggest the need for epidemiological surveillance in the region of the Chapada do Araripe.

  2. Life cycle, feeding and defecation patterns of Rhodnius ecuadoriensis (Lent & León 1958) (Hemiptera: Reduviidae: Triatominae) under laboratory conditions.

    Science.gov (United States)

    Villacís, Anita G; Arcos-Terán, Laura; Grijalva, Mario J

    2008-11-01

    Rhodnius ecuadoriensis is the second most important vector of Chagas Disease (CD) in Ecuador. The objective of this study was to describe (and compare) the life cycle, the feeding and defecation patterns under laboratory conditions of two populations of this specie [from the provinces of Manabí (Coastal region) and Loja (Andean region)]. Egg-to-adult (n = 57) development took an average of 189.9 +/- 20 (Manabí) and 181.3 +/- 6.4 days (Loja). Mortality rates were high among Lojan nymphs. Pre-feeding time (from contact with host to feeding initiation) ranged from 4 min 42 s [nymph I (NI)] to 8 min 30 s (male); feeding time ranged from 14 min 45 s (NI)-28 min 25 s (male) (Manabí) and from 15 min 25 s (NI)-28 min 57 s (nymph V) (Loja). The amount of blood ingested increased significantly with instar and was larger for Manabí specimens (p Ecuador and Northern Peru.

  3. Life cycle, feeding and defecation patterns of Rhodnius ecuadoriensis (Lent & León 1958 (Hemiptera: Reduviidae: Triatominae under laboratory conditions

    Directory of Open Access Journals (Sweden)

    Anita G Villacís

    2008-11-01

    Full Text Available Rhodnius ecuadoriensis is the second most important vector of Chagas Disease (CD in Ecuador. The objective of this study was to describe (and compare the life cycle, the feeding and defecation patterns under laboratory conditions of two populations of this specie [from the provinces of Manabí (Coastal region and Loja (Andean region]. Egg-to-adult (n = 57 development took an average of 189.9 ± 20 (Manabí and 181.3 ± 6.4 days (Loja. Mortality rates were high among Lojan nymphs. Pre-feeding time (from contact with host to feeding initiation ranged from 4 min 42 s [nymph I (NI] to 8 min 30 s (male; feeding time ranged from 14 min 45 s (NI-28 min 25 s (male (Manabí and from 15 min 25 s (NI-28 min 57 s (nymph V (Loja. The amount of blood ingested increased significantly with instar and was larger for Manabí specimens (p < 0.001. Defecation while feeding was observed in Manabí specimens from stage nymph III and in Lojan bugs from stage nymph IV. There was a gradual, age-related increase in the frequency of this behaviour in both populations. Our results suggest that R. ecuadoriensis has the bionomic traits of an efficient vector of Trypanosoma cruzi. Together with previous data on the capacity of this species to infest rural households, these results indicate that control of synanthropic R. ecuadoriensis populations in the coastal and Andean regions may have a significant impact for CD control in Ecuador and Northern Peru.

  4. Domestic Rhodnius ecuadoriensis (Hemiptera, Reduviidae) infestation in Northern Peru: a comparative trial of detection methods during a six-month follow-up.

    Science.gov (United States)

    Cuba Cuba, César Augusto; Vargas, Franklin; Roldan, Judith; Ampuero, Cynthia

    2003-01-01

    Two passive methods in the assessment of intradomiciliary infestation by Rhodnius ecuadoriensis were tested: (i) the Gomes Nu ez sensor box (GN), (ii) sheets of white typing paper and (iii) one active timed manual method. The study was carried out in the Alto Chicama River Valley, Province of Gran Chim , Department of La Libertad. The study design consisted of an initial searching of triatomines inside of the domestic environment by the manual capture active procedure (man/hour) covering all the studied houses. Then, matched pairs of GN boxes and paper sheets were simultaneously installed in the bedrooms of 207 households distributed in 19 localities. A comparative prospective trial of these passive detection devices were monitored at 2, 4 and, finally 6 months follow-up. Parasitological Trypanosoma rangeli and/or T. cruzi infections were investigated in two houses with high level of infestation by R. ecuadoriensis. 16.9% of the 207 households investigated by an initial active manual method were infested with R. ecuadoriensis. The proportion of infested houses fluctuated from 6.2 to 55.5% amongst the 19 localities investigated. T. rangeli natural infection was detected in R. ecuadoriensis specimens collected in two households. Parasite rates in the bugs ranged from 16.6 to 21.7% respectively. The most striking fact was an average rate of salivary gland infection ranging from 7.4 to 8.3%. At the end of the sixth month period, a cumulative incidence of 31.4% of positive GN boxes against 15.9% for paper sheets was recorded. All three methods combined detected domestic infestation in 129 (62.3%) of the 207 houses studied in the 19 localities. The range of houses infested varies from 6.7% to 92.9%. In areas with low bug density infestation rates, the methodology experienced in our studies, seems to be the best choice for investigations on domestic R. ecuadoriensis populations.

  5. Conocimientos y factores de riesgo relacionados con la enfermedad de Chagas en dos comunidades panameñas donde Rhodnius pallescens es el vector principal

    Directory of Open Access Journals (Sweden)

    Lisbeth A. Hurtado

    2014-06-01

    Full Text Available Introducción. La implementación de los programas de vigilancia, prevención y control de la enfermedad de Chagas requiere una aproximación integral. La sostenibilidad de los programas depende de la participación comunitaria amparada en un conocimiento básico del problema. Objetivo. Evaluar los conocimientos de los entrevistados que facilitan o limitan la vigilancia, prevención y control de la enfermedad de Chagas en dos comunidades endémicas de Panamá donde Rhodnius pallescens es el vector principal. Materiales y métodos. Mediante un cuestionario se evaluaron los conocimientos y los factores de riesgo relacionados con la enfermedad de Chagas en 201 personas mayores de 10 años de las comunidades endémicas de Las Pavas y Lagartera Grande, ubicadas en la ribera oeste del Canal de Panamá. Con ayuda de los moradores también se evaluó la presencia de chinches triatominos en 93 viviendas a lo largo de un año. Resultados. De las personas entrevistadas, 69,2 % (139/201 tenía pocos o muy pocos conocimientos sobre la enfermedad de Chagas y 93 % (187/201 estaba expuesto a factores de riesgo moderados o altos. Se capturaron chinches triatominos en 20,4 % (19/93 de las viviendas evaluadas, de los cuales, el 86,8 % (66/76 era R. pallescens. Se encontró asociación significativa entre la presencia de chinches dentro de las viviendas y las viviendas catalogadas como precarias (p<0,01. Conclusión. A pesar de que en estas dos comunidades se han desarrollado programas de educación sanitaria, es necesario reforzar los conocimientos básicos sobre la enfermedad de Chagas antes de establecer medidas de prevención y vigilancia que involucren la participación activa de sus habitantes.

  6. The characterization of new hormonal systems in arthropods with a focus on neuropeptide GPCRs

    DEFF Research Database (Denmark)

    Stafflinger, Elisabeth

    Anopheles gambiae, Aedes aegypti, and Culex pipiens, the silkworm Bombyx mori, T. castaneum, N. vitripennis, and the bug Rhodnius prolixus but not in all the other sequenced insect genomes. Bioassays showed that only ACP can activate the ACPR, but not AKH or corazonin, showing that this system...

  7. partial characterisation of a trypanosome-lysing

    African Journals Online (AJOL)

    2003-11-01

    Nov 1, 2003 ... Crithidia or Leishmania parasites. Ibrahim et al.(9) further showed that the haemolymph factor was a lectin. ' andahat the midgut. also contained another lectin with different specificity. In Rhodnius prolixus Stal, the vector for Trypanosoma cruzi Chagas, lectins from the haemolymph and the gut agglutinated ...

  8. Estrutura de populações de Rhodnius neglectus Lent e Psammolestes tertius Lent & Jurberg (Hemiptera, Reduviidae em ninhos de pássaros (Furnariidae presentes na palmeira Mauritia flexuosa no Distrito Federal, Brasil Population structure of Rhodnius neglectus Lent and Psammolestes tertius Lent & Jurberg (Hemiptera, Reduviidae in bird nests (Furnariidae on Mauritia flexuosa palm trees in Federal District of Brazil

    Directory of Open Access Journals (Sweden)

    Rodrigo Gurgel-Gonçalves

    2007-03-01

    Full Text Available Rhodnius neglectus Lent, 1954 {Rn}e Psammolestes tertius Lent & Jurberg, 1965 {Pt} são triatomíneos que ocorrem em ninhos de aves, principalmente da família Furnariidae. O ciclo biológico dessas espécies é conhecido em condições de laboratório, sendo poucos estudos em ecótopos silvestres. Para analisar a infestação e estrutura de populações de Rn e Pt em ninhos de aves presentes na palmeira Mauritia flexuosa Linnaeus, em duas estações climáticas do Brasil Central, foram amostradas 41 palmeiras com evidências de nidificação de Phacellodomus ruber Vieillot, 1817 (22 na estação chuvosa e 19 na estação seca em quatro áreas do Distrito Federal. Os insetos foram capturados usando-se coleta manual na copa da palmeira, identificados morfologicamente, separados por sexo e estádio ninfal. Fezes e glândulas salivares de Rn foram examinadas para verificar infecção por Trypanosoma cruzi Chagas, 1909 e/ou T. rangeli Tejera, 1920. Trinta e cinco palmeiras com ninhos de P. ruber estavam infestadas por Rn (85% e 22 por Pt (53%. 442 indivíduos foram coletados na estação seca (200 Rn e 242 Pt e 267 na estação chuvosa (136 Rn e 131 Pt. O único fator relacionado significativamente com a densidade de triatomíneos nas palmeiras foi a área. A estrutura etária das populações mostrou: a maior abundância de adultos nas populações de Pt, b maior abundância de machos em ambas as espécies e c presença de fêmeas ovipondo em ambas as estações. Nenhum dos 177 triatomíneos examinados estava infectado por T. cruzi ou T. rangeli. A estrutura etária das populações de Rn e Pt não diferiu significativamente entre as estações amostradas, indicando ausência de marcada sazonalidade para essas espécies.Rhodnius neglectus Lent, 1954 {Rn}and Psammolestes tertius Lent & Jurberg, 1965 {Pt} are triatomines that occur in bird nests, mainly furnarid nests. Their biological cycles are known in laboratory conditions and few studies were

  9. A novel association between Rhodnius neglectus and the Livistona australis palm tree in an urban center foreshadowing the risk of Chagas disease transmission by vectorial invasions in Monte Alto City, São Paulo, Brazil.

    Science.gov (United States)

    Carvalho, Danila B; Almeida, Carlos E; Rocha, Cláudia S; Gardim, Sueli; Mendonça, Vagner J; Ribeiro, Aline R; Alves, Zulimar C P V T; Ruellas, Kellem T; Vedoveli, Alan; da Rosa, João A

    2014-02-01

    After several public notifications of domiciliary invasions, palm trees were investigated in downtown Monte Alto City, São Paulo State, Brazil, in proximity to the city hall building, the main church, condominiums and marketing establishments. One hundred seventy four palm trees of 10 species were investigated, in which 72 specimens of Rhodnius neglectus, a potential Chagas disease vector, were captured via manual methods. All insects were collected from dead leaves, organic debris and bird nests in the only three Livistona australis palm trees in the central park square. This was the first record of R. neglectus colonizing this palm species. Although no Trypanosoma cruzi was found by abdominal compression followed by light microscopy, the poor nutritional status of the bugs hampered the examination of gut contents for parasite detection. Furthermore, the central crowns of the trees, which shelter bats (Chiroptera: Mammalia), could not be carefully searched for insects due to difficult access. This new finding highlights the sudden alteration in insect behavior, probably as a result of man's interference. This report aims to warn those involved in the health system about this new threat, justifying detailed research of the area to evaluate the magnitude of this emerging public health issue. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Hematophagous insects as vectors for frog trypanosomes.

    Science.gov (United States)

    Ramos, B; Urdaneta-Morales, S

    1977-12-01

    Experimental infections of three hematophagous arthropods (Rhodnius prolixus, Aedes aegypti, and Culex pipiens) with a trypanosome of the Trypanosoma rotatorium complex found in the frogs Hyla crepitans and Leptodactylus insularum revealed that A. aegypti is a good host for the flagellate; the course of development in the intestinal tract of the mosquito is described from 15 minutes to 168 hours. C. pipiens showed only low intestinal infections and R. prolixus did not permit development of the parasite. It is postulated that, in addition to the transmission of T. rotatorium by leeches, batrachophilic mosquitoes may transmit the parasite to frogs of more terrestrial habits by being ingested by these anurans.

  11. Cysteine proteases from bloodfeeding arthropod ectoparasites

    Czech Academy of Sciences Publication Activity Database

    Sojka, Daniel; Francischetti, I.M.B.; Calvo, E.; Kotsyfakis, Michalis

    2011-01-01

    Roč. 712, - (2011), s. 177-191 ISSN 0065-2598 R&D Projects: GA AV ČR IAA600960910; GA AV ČR IAA600960811; GA AV ČR KJB600960911; GA MŠk(CZ) LC06009 Institutional research plan: CEZ:AV0Z60220518 Keywords : TICK HAEMAPHYSALIS-LONGICORNIS * PROLIXUS STAL HEMIPTERA * YELLOW-FEVER MOSQUITO * BLOOD-MEAL DIGESTION * L-LIKE ENZYME * BOOPHILUS-MICROPLUS * RHODNIUS-PROLIXUS * CATHEPSIN-B * ASPARAGINYL ENDOPEPTIDASES/LEGUMAINS * PROTEOLYTIC ACTIVATION Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.093, year: 2011

  12. Kultuuriruum ja Natalie Mei prostitutsiooniteemalised joonistused / Kai Stahl

    Index Scriptorium Estoniae

    Stahl, Kai

    2011-01-01

    Analüüsitakse feministliku lugemise ja Juri Lotmani kultuurisemiootika abil kultuuri ja "mittekultuuri" vahelist piiriala, keskendudes viisidele, kuidas Natalie Mei erines oma joonistustega kunsti üldpildist - rikkudes traditsionaalset pildikoodi, ironiseerib Mei selle teema domineerivat käsitlust ja pildilist kuvamist, luues naiskunstnikuna uue vaatenurga

  13. Epidemiologia da doença de Chagas na zona rural do Município de Teresina-Piauí, Brasil

    Directory of Open Access Journals (Sweden)

    Dalva Neves da Costa Bento

    1992-03-01

    Full Text Available Na área rural do município de Teresina-Piauí, foram capturados 129 triatomíneos distribuídos em (a ecótopos artificiais: habitações (1 Triatoma brasiliensis, 1 Panstrongylus geniculatus, 1 Rhodnius pictipes e 1 Rhodnius prolixusj e galpão abandonado (7 Rhodnius nasutusj e (b ecótopos naturais: Orbignya martiana (41 Rhodnius neglectus, 33 Rhodnius prolixus e 41 Rhodnius nasutus, e Copernicia cerifera (3 Rhodnius neglectus,. Cerca de 22,6% dos triatomíneos capturados estavam infectados por flagelados, sendo 30% no ambiente artificial e 21,9% no ambiente natural. Dos 28 mamíferos capturados e examinados, 7 Didelphis aibiventris, 2 Rattus rattus e 1 Tamandua tetradacty la apresentavam-se positivos para flagelados. Os flagelados encontrados nos triatomíneos e nos mamíferos eram semelhantes ao Trypanosoma cruzi. Das 123 reações sorológicas, por imunojluorescência indireta, realizadas na população, duas (1,6% foram reativas.

  14. Countercurrent heat exchange and thermoregulation during blood-feeding in kissing bugs.

    Science.gov (United States)

    Lahondère, Chloé; Insausti, Teresita C; Paim, Rafaela Mm; Luan, Xiaojie; Belev, George; Pereira, Marcos H; Ianowski, Juan P; Lazzari, Claudio R

    2017-11-21

    Blood-sucking insects experience thermal stress at each feeding event on endothermic vertebrates. We used thermography to examine how kissing-bugs Rhodnius prolixus actively protect themselves from overheating. During feeding, these bugs sequester and dissipate the excess heat in their heads while maintaining an abdominal temperature close to ambient. We employed a functional-morphological approach, combining histology, µCT and X-ray-synchrotron imaging to shed light on the way these insects manage the flow of heat across their bodies. The close alignment of the circulatory and ingestion systems, as well as other morphological characteristics, support the existence of a countercurrent heat exchanger in the head of R. prolixus , which decreases the temperature of the ingested blood before it reaches the abdomen. This kind of system has never been described before in the head of an insect. For the first time, we show that countercurrent heat exchange is associated to thermoregulation during blood-feeding.

  15. Biology, diversity and strategies for the monitoring and control of triatomines--Chagas disease vectors.

    Science.gov (United States)

    Costa, Jane; Lorenzo, Marcelo

    2009-07-01

    Despite the relevant achievements in the control of the main Chagas disease vectors Triatoma infestans and Rhodnius prolixus, several factors still promote the risk of infection. The disease is a real threat to the poor rural regions of several countries in Latin America. The current situation in Brazil requires renewed attention due to its high diversity of triatomine species and to the rapid and drastic environmental changes that are occurring. Using the biology, behaviour and diversity of triatomines as a basis for new strategies for monitoring and controlling the vectorial transmission are discussed here. The importance of ongoing long-term monitoring activities for house infestations by T. infestans, Triatoma brasiliensis, Panstrongylus megistus, Triatoma rubrovaria and R. prolixus is also stressed, as well as understanding the invasion by sylvatic species. Moreover, the insecticide resistance is analysed. Strong efforts to sustain and improve surveillance procedures are crucial, especially when the vectorial transmission is considered interrupted in many endemic areas.

  16. Dicty_cDB: Contig-U04780-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available Ancylostoma ceylanicum L3 Ancylostoma ... 44 6.7 1 ( GE813038 ) EST_scau_evk_974138 scauevk mixed_tissue Sebaste...s... 44 6.7 1 ( GE802768 ) EST_scau_evk_897256 scauevk mixed_tissue Sebastes... 44 6.7 1 ( GE802767 ) ES...T_scau_evk_896872 scauevk mixed_tissue Sebastes... 44 6.7 1 ( GE800881 ) EST_scau..._evk_891797 scauevk mixed_tissue Sebastes... 44 6.7 1 ( FD779328 ) NADG-aaa04h04.g1 Rhodnius_prolixus_EST_NA

  17. A mathematical model of Chagas disease transmission

    Science.gov (United States)

    Hidayat, Dayat; Nugraha, Edwin Setiawan; Nuraini, Nuning

    2018-03-01

    Chagas disease is a parasitic infection caused by protozoan Trypanosoma cruzi which is transmitted to human by insects of the subfamily Triatominae, including Rhodnius prolixus. This disease is a major problem in several countries of Latin America. A mathematical model of Chagas disease with separate vector reservoir and a neighboring human resident is constructed. The basic reproductive ratio is obtained and stability analysis of the equilibria is shown. We also performed sensitivity populations dynamics of infected humans and infected insects based on migration rate, carrying capacity, and infection rate parameters. Our findings showed that the dynamics of the infected human and insect is mostly affected by carrying capacity insect in the settlement.

  18. Historia de la Tripanosomiasis Americana en Colombia

    Directory of Open Access Journals (Sweden)

    Fernando Serpa Florez

    2000-08-01

    cruzi fueron realizados por César Uribe Piedrahita en 1929. Encontró vectores del mal infectados con estos flagelados en Prado (Tolima como lo públicó en su trascendental comunicación “Infección de Rhodnius prolixus Stahl por Trypanosoma cruzi y Trypanosoma rangeli”, en la Revista Médico-Quirúrgica de los Hospitales de Bogotá, de dicho año (3...

  19. Laser brazing of hard metal on steel; Laserstrahlloeten von Hartmetall an Stahl

    Energy Technology Data Exchange (ETDEWEB)

    Haferkamp, H.; Frohmann, A.; Block, B.; Goede, M. [Laser Zentrum Hannover e.V., Hannover (Germany); Muenz, U. [Forschungsgemeinschaft Werkzeuge und Werkstoffe e.V., Remscheid (Germany)

    2001-07-01

    Topic of the investigations presented here is the laser beam brazing of hardmetal plates onto tool steel. Three different kinds of laser beam sources are comparatively used, a diode laser, a Nd:YAG laser and a CO{sub 2} laser. The investigations concentrate on the variation of two process parameters: brazing time and laser performance. Following the brazing process both visual observation as well as hardness measurements and shear tests are made. The investigations show that by brazing, high seam qualities can be achieved, which withstand the comparison with inductively brazed joints. (orig.)

  20. Nitric oxide heme interactions in nitrophorin from Cimex lectularius

    Energy Technology Data Exchange (ETDEWEB)

    Christmann, R.; Auerbach, H., E-mail: auerbach@physik.uni-kl.de [University of Kaiserslautern, Department of Physics (Germany); Berry, R. E.; Walker, F. A. [The University of Arizona, Department of Chemistry and Biochemistry (United States); Schünemann, V. [University of Kaiserslautern, Department of Physics (Germany)

    2016-12-15

    The nitrophorin from the bedbug Cimex lectularius (cNP) is a nitric oxide (NO) carrying protein. Like the nitrophorins (rNPs) from the kissing bug Rhodnius prolixus, cNP forms a stable heme Fe(III)-NO complex, where the NO can be stored reversibly for a long period of time. In both cases, the NPs are found in the salivary glands of blood-sucking bugs. The insects use the nitrophorins to transport the NO to the victim’s tissues, resulting in vasodilation and reduced blood coagulation. However, the structure of cNP is significantly different to those of the rNPs from Rhodnius prolixus. Furthermore, the cNP can bind a second NO molecule to the proximal heme cysteine when present at higher concentrations. High field Mössbauer spectroscopy on {sup 57}Fe enriched cNP complexed with NO shows reduction of the heme iron and formation of a ferrous nitric oxide (Fe(II)-NO) complex. Density functional theory calculations reproduce the experimental Mössbauer parameters and confirm this observation.

  1. Feeding sources and trypanosome infection index of Rhodnius pallescens in a Chagas disease endemic area of Amador County, Panama Fontes de alimentação de R. pallescens e índice de infecção por Trypanosoma em área endêmica da doença de Chagas em Amador, região central do Panamá

    Directory of Open Access Journals (Sweden)

    Vanessa Pineda

    2008-04-01

    Full Text Available The sylvatic triatomine Rhodnius pallescens is considered to be the most important and widespread vector of Trypanosoma cruzi and Trypanosoma rangeli in Panama. However, its behavior and biological characteristics have only been partially investigated. Thus, to achieve sustainable and efficient control over Chagas disease in Panama, a better understanding of the ecology and biology of R. pallescens is essential. In this study we evaluated R. pallescens host feeding sources using a dot-blot assay, and the trypanosome infection index by PCR analysis in a Chagas disease endemic area of central Panama. It was found that in peridomestic palm trees, 20.3% of the examined bugs had fed on opossums (Didelphis marsupialis. However, we observed an increased anthropophagy (25.4% for those bugs collected inside houses. Considering the domestic and peridomestic habitats as a whole, the proportion of collected R. pallescens infected with trypanosomes was 87.4%. In the two habitats the predominant infection was with T. cruzi (80-90%. Between 47-51% of the analyzed triatomines were infected with T. rangeli. Mixed infections (40-51% were also detected. These findings provide a better basis for the implementation of a rational control and surveillance program for Chagas disease in regions where R. pallescens is endemic.O triatomíneo silvestre Rhodnius pallescens é considerado o mais importante vetor do Trypanosoma cruzi e Trypanosoma rangeli no Panamá. Entretanto, seu comportamento e características biológicas são pouco estudados. Para controlar a doença de Chagas no Panamá é necessário melhorar a compreensão dos aspectos eco-biológicos do R. pallescens. Neste estudo, investigaram-se as fontes de alimentação de R. pallescens usando dot-blot e o índice de infecção por Trypanosoma por metodologia molecular, em área endêmica da doença de Chagas na região central do Panamá. Foi observado que 20,3% dos barbeiros coletados em palmeiras peridom

  2. Characterisation of Q and T steel pole shoes manufactured by sand casting; Charakterisierung mit Sandguss hergestellter Polschuhe aus verguetetem Stahl

    Energy Technology Data Exchange (ETDEWEB)

    Asensio-Lozano, J.; Alvarez-Antolin, J.F. [Oviedo Univ. (Spain). Dept. of Materials Science and Metallurgical Engineering; Panta-Mesones, J.T. [National Univ. of Trujillo, La Libertad (Peru). Faculty of Mines, Metallurgy and Materials; Vander-Voort, G.F. [Buehler Ltd., Lake Bluff, IL (United States)

    2008-04-15

    This paper presents a study of the microstructural and mechanical characterization of the GS 35 CrMoV 10 4 alloy employed in the manufacture of sand-cast pole shoes for 4-pole synchronous electric power generators working at a frequency of 60 Hz. In addition, the most appropriate treatment for ensuring compliance with the technical specifications defined in DIN Standard No. 1.7755 has been designed. (orig.)

  3. Butt pressure welding of wheels from vehicles consisting of steel and aluminium; Pressstumpfschweissen von Fahrzeugraedern aus Stahl und Aluminium

    Energy Technology Data Exchange (ETDEWEB)

    Grobelin, K. [Hess Engineering AG, Frauenfeld (Switzerland)

    2001-07-01

    Every year in Europe 35 million wheels for vehicles are produced. Most of them are wheels consisting of metal tapes, both of steel and of aluminium alloys. The manufacturing of wheels is explained, in detail the method known as DC upset welding used for butt joints of wheel-rims. The engaged machinery, the specials of welding various materials, the limits of the method, and the quality assurance are discussed. Advantages of the applied method are joints of first-class quality, high productivity, energy saving and environmental cleanness. (orig.)

  4. Effect of different strain distributions on the phase transformations in steel. Einfluss verschiedener Dehnungszustaende auf das Umwandlungsverhalten eines Stahls

    Energy Technology Data Exchange (ETDEWEB)

    Lyra, A.; Dahl, W. (Technische Hochschule Aachen (Germany, F.R.). Inst. fuer Eisenhuettenkunde)

    1990-01-01

    Using tensile specimens with two different geometries (notched and unnotched) and five cooling rates the anisothermal phase transformation of a 100 Cr 6 steel has been investigated under influence of different strain distributions inside the specimens. The nonhomogeneous distribution of plastic strain has been achieved by tensile testing at high temperatures (800deg C). Measurement of the transformation temperatures was carried out by dilatometry and differential thermal analysis (DTA). The results reveal that due to hot deformation the pearlitic transformation curves in the CCT-Diagram are dislocated to shorter times and higher temperatures compared with the underformed state. The extent of the displacement is however a function of the strain distribution inside the specimens. (orig.).

  5. Aluminum or steel? Mounting systems for solar generators - a practice report; Aluminium oder Stahl? Montagesysteme fuer Solargeneratoren - ein Praxisreport

    Energy Technology Data Exchange (ETDEWEB)

    Schnitzer, Sandy [Mounting Systems GmbH, Rangsdorf (Germany); Hannemann, Lydia

    2013-10-01

    Mounting systems for solar generators must be solid and reliable as long as possible so that they carry the modules. Which material is best? [German] Montagesysteme fuer Solargeneratoren muessen solide sein, damit sie moeglichst lange und zuverlaessig die Module tragen.

  6. [Use of new tools for controlling triatomines in different entomologic situations in the American continent].

    Science.gov (United States)

    Oliveira Filho, A M

    1997-01-01

    The field results of new tools for triatomine control developed under the sponsorship of WHO/TDR are reported: a) A slow-release "paint" containing malathion; b) fumigant cans containing cypermethrin and DDVP, and c) sensor boxes for the detection of triatomine infestations. Field assays were performed in Chile, Honduras and Paraguay against Triatoma infestans, T. dimidiata and Rhodnius prolixus, accordingly to a standard protocol designed by a WHO experts committee. Preliminary 6 months post-treatment results for the three countries show an efficient control when insecticide paints were used indoors and in the peridomicilium, keeping reinfestation near zero. The final results presented for Chile two years post-treatment confirmed the superiority of the slow-release "paints". Sensor boxes were less effective than man/hour captures in the detection of infested houses.

  7. Genetic basis of triatomine behavior: lessons from available insect genomes

    Directory of Open Access Journals (Sweden)

    Jose Manuel Latorre-Estivalis

    2013-01-01

    Full Text Available Triatomines have been important model organisms for behavioural research. Diverse reports about triatomine host search, pheromone communication in the sexual, shelter and alarm contexts, daily cycles of activity, refuge choice and behavioural plasticity have been published in the last two decades. In recent times, a variety of molecular genetics techniques has allowed researchers to investigate elaborate and complex questions about the genetic bases of the physiology of insects. This, together with the current characterisation of the genome sequence of Rhodnius prolixus allows the resurgence of this excellent insect physiology model in the omics era. In the present revision, we suggest that studying the molecular basis of behaviour and sensory ecology in triatomines will promote a deeper understanding of fundamental aspects of insect and, particularly, vector biology. This will allow uncovering unknown features of essential insect physiology questions for a hemimetabolous model organism, promoting more robust comparative studies of insect sensory function and cognition.

  8. Seroprevalence of human Trypanosoma cruzi infection in diferent geografic zones of Chiapas, Mexico.

    Science.gov (United States)

    Mazariego-Arana, M A; Monteón, V M; Ballinas-Verdugo, M A; Hernández-Becerril, N; Alejandre-Aguilar, R; Reyes, P A

    2001-01-01

    A serologic survey was carried out in four different geographic zones of Chiapas, Mexico. A total of 1,333 samples were collected from residents of thirteen communities located on the Coast, Central Mountain, Lacandon Forest and a zone called Mesochiapas. One hundred and fifty one seropositive individuals (11.3%) were identified. Human Trypanosoma cruzi infection was influenced by geography. In the Lacandon Forest and Central Mountains there was a higher seroprevalence 32.1 and 13.8% respectively, than on the coast (1.2%). In Mesochiapas there were no seropositive individuals among the 137 persons tested. An active transmission is probably continuing because seropositive cases (13.8%) were detected in children under 10 years of age. The vector recognized on the Coast was Triatoma dimidiata while in the Lacandon Forest it was Rhodnius prolixus.

  9. Lysophosphatidylcholine: A Novel Modulator of Trypanosoma cruzi Transmission

    Science.gov (United States)

    Silva-Neto, Mário A. C.; Carneiro, Alan B.; Silva-Cardoso, Livia; Atella, Georgia C.

    2012-01-01

    Lysophosphatidylcholine is a bioactive lipid that regulates a large number of cellular processes and is especially present during the deposition and infiltration of inflammatory cells and deposition of atheromatous plaque. Such molecule is also present in saliva and feces of the hematophagous organism Rhodnius prolixus, a triatominae bug vector of Chagas disease. We have recently demonstrated that LPC is a modulator of Trypanosoma cruzi transmission. It acts as a powerful chemoattractant for inflammatory cells at the site of the insect bite, which will provide a concentrated population of cells available for parasite infection. Also, LPC increases macrophage intracellular calcium concentrations that ultimately enhance parasite invasion. Finally, LPC inhibits NO production by macrophages stimulated by live T. cruzi, and thus interferes with the immune system of the vertebrate host. In the present paper, we discuss the main signaling mechanisms that are likely used by such molecule and their eventual use as targets to block parasite transmission and the pathogenesis of Chagas disease. PMID:22132309

  10. The isolation and identification of Trypanosoma cruzi from raccoons in Maryland

    Science.gov (United States)

    Walton, B.C.; Bauman, P.M.; Diamond, L.S.; Herman, C.M.

    1958-01-01

    Five raccoons trapped at Patuxent Research Refuge, Laurel, Maryland, were found to have trypanosomes in the blood which were morphologically indistinguishable from Trypanosoma cruzi on stained smears. The organism grew well in culture. It developed and reproduced in Triatoma protracta, T. infestans, T. phyllosoma, and Rhodnius prolixus. Experimental infections were produced in raccoons, opossums, mice, rats, and monkeys by inoculation of blood, culture, and triatome forms. Typical leishmaniform bodies were found in tissue sections of cardiac muscle fibers from naturally and experimentally infected animals. Cross agglutinations carried out with Iiving cultural forms and rabbit antisera demonstrated a close antigenic relationship between the raccoon trypanosome and T. cruzi (Brazil strain). On the basis of (1) morphology, (2) presence of leishmaniform tissue stages, (3) development in triatomes, (4) infectivity to a variety of mammals, (5) culture characteristics, and (6) cross reactions in serological tests, this parasite is considered conspecific with Trypanosoma cruzi (Chagas, 1909), the causative agent of American human trypanosomiasis.

  11. Modeling the effects of palm-house proximity on the theoretical risk of Chagas disease transmission in a rural locality of the Orinoco basin, Colombia

    Directory of Open Access Journals (Sweden)

    Diana Erazo

    2016-11-01

    Full Text Available Abstract Background Chagas disease is a major public health concern in Latin America and it is transmitted by insects of the subfamily Triatominae, including Rhodnius spp. Since palm trees are ubiquitous in Colombia and a habitat for Rhodnius spp., the presence of palms near villages could increase contact rates between vectors and humans. Therefore, knowing whether a relationship exists between the proximity of palms to villages and the abundance and distribution of vectors therein, may be critical for Chagas disease prevention programs. Adapting a mathematical model for R. prolixus population dynamics in a small village, we model the implications of changing distances between palms and dwellings, to the risk of Chagas disease infection. Methods We implemented a mathematical model that reflects R. prolixus population dynamics in a small village located in the department of Casanare (Colombia to study the role of palm-house proximity. We varied the distance between palms and houses by monitoring the network global efficiency metric. We constructed 1,000 hypothetical villages varying distances and each one was run 100 times. Results According to the model, as palm-house proximity increases, houses were more likely to be visited by triatomine bugs. The number of bugs per unit time increased progressively in a non-linear fashion with high variability. We stress the importance of village configuration on the model output. Conclusions From a theoretical perspective, palm-house proximity may have a positive effect on the incidence of Chagas disease. The model predicts a 1% increase in new human cases per year when houses and palms are brought closer by 75%.

  12. A multidisciplinary approach to the study of the fluminense vegetation

    Directory of Open Access Journals (Sweden)

    ALPHONSE KELECOM

    2002-03-01

    Full Text Available The fluminense vegetation, more specifically the flora from the Jurubatiba restinga has been investigated by a multidisciplinary team of botanists, chemist, radiobiologist, insect physiologists and geneticist. Vouchers of 564 specimens have been collected, identified, organized in an herbarium, and a database is being build up containing, in addition to classical botanical data, chemical data and information on the potential economic use either for landscape gardening, alternative foods or as medicinal plants. Phytochemical studies of the Guttiferae, Clusia hilariana, yielded oleanolic acid and nemorosone. Their biological activities against the haematophagous insect Rhodnius prolixus vector of Chagas disease have been investigated. Finally, it has been observed that aquatic plants possessed high levels of the natural radionuclide polonium-210, which seems to be originated mainly from soil rather than from atmospheric supply.A vegetação fluminense, em particular aquela proveniente da Restinga de Jurubatiba, foi investigada por um grupo multidisciplinar de botânicos, químico, radiobiólogo, fisiologistas de insetos e geneticista. Amostras de 564 espécimes foram coletadas, identificadas, organizadas em herbário e um banco de dados está sendo elaborado contendo, além das clássicas informações botânicas, dados químicos e indicações quanto ao uso econômico potencial destas plantas, em paisagismo, como alimentos alternativos ou como plantas medicinais. Estudos fitoquímicos da Guttiferae, Clusia hilariana, forneceram ácido oleanólico e nemorosona. Estes metabólitos foram ensaiados no barbeiro Rhodnius prolixus, vetor da doença de Chagas. Por fim, observou-se que plantas aquáticas apresentaram teores muito altos do radionuclídeo natural, polônio-210, fato este que parece estar relacionado mais com as condições de solo do que com um aporte atmosférico.

  13. Seroprevalence of human Trypanosoma cruzi infection in diferent geografic zones of Chiapas, Mexico Soroprevalência da infecção humana pelo Trypanosoma cruzi em diferentes regiões de Chiapas, México

    Directory of Open Access Journals (Sweden)

    Miguel Angel Mazariego-Arana

    2001-10-01

    Full Text Available A serologic survey was carried out in four different geographic zones of Chiapas, Mexico. A total of 1,333 samples were collected from residents of thirteen communities located on the Coast, Central Mountain, Lacandon Forest and a zone called Mesochiapas. One hundred and fifty one seropositive individuals (11.3% were identified. Human Trypanosoma cruzi infection was influenced by geography. In the Lacandon Forest and Central Mountains there was a higher seroprevalence 32.1 and 13.8% respectively, than on the coast (1.2%. In Mesochiapas there were no seropositive individuals among the 137 persons tested. An active transmission is probably continuing because seropositive cases (13.8% were detected in children under 10 years of age. The vector recognized on the Coast was Triatoma dimidiata while in the Lacandon Forest it was Rhodnius prolixus.Foi feito um estudo sorológico em quatro zonas geográficas do estado de Chiapas México. Foram colhidas 1333 amostras dos habitantes das 13 comunidades situadas na costa, na região central montanhosa, na floresta lacandona e na região chamada mesochiapas. Cento cinqüenta e uma pessoas (11,3% foram identificadas como soropositivas. A infecção pelo Trypanosoma cruzi teve a influência da geografia local. Na floresta lacandona nas montanhas centrais, foi encontrada uma prevalência de 32,1 e 13,8% respectivamente, mais que na costa 1,2%. Na zona de mesochiapas não foi encontrada nenhuma pessoa com sorologia positiva entre 137 estudadas. Como encontramos sorologia positiva em crianças menores de 10 anos, pensamos que exista uma transmissão ativa contínua. Na costa foi reconhecido o vetor Triatoma dimidiata e na floresta Lacandona o Rhodnius prolixus.

  14. Triatominos (Reduviidae: Triatominae en un foco de enfermedad de Chagas en Talaigua Nuevo (Bolívar, Colombia.

    Directory of Open Access Journals (Sweden)

    Luis Alberto Corté

    2005-12-01

    Full Text Available Introducción. Se describen las características e importancia epidemiológica de los triatominos presentes en un foco de enfermedad de Chagas en el municipio de Talaigua Nuevo, departamento de Bolívar. Objetivo. Determinar y correlacionar características ecológicas de los triatominos presentes en un foco de Chagas en el municipio de Talaigua Nuevo, Bolívar. Materiales y métodos. La captura de los triatominos se realizó en 300 domicilios del casco urbano en los que se revisaron el intra y peridomicilio, así como ambientes extradomésticos (palmas de vino y cúmulos de madera y leña. Resultados. Se capturaron 103 triatominos pertenecientes a cuatro especies: Triatoma maculata, Eratyrus cuspidatus, Panstrongylus geniculatus y Rhodnius prolixus. T. maculata, fue la especie predominante (92,3%. El 93% de los triatominos fueron capturados en ambientes intradomiciliarios. Conclusión. Se reporta por primera vez en Bolívar la captura de individuos de T. maculata infectados naturalmente con Trypanosoma sp. Se amplía la distribución geográfica de P. geniculatus y R. prolixus. El análisis de correspondencias múltiples no encontró ninguna relación significativa entre las características físicas de las viviendas y la presencia de triatominos dentro de ellas.

  15. Structure and ligand-binding properties of the biogenic amine-binding protein from the saliva of a blood-feeding insect vector of Trypanosoma cruzi

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Xueqing; Chang, Bianca W. [NIH/NIAID, 12735 Twinbrook Parkway, Rockville, MD 20852 (United States); Mans, Ben J. [NIH/NIAID, 12735 Twinbrook Parkway, Rockville, MD 20852 (United States); Agricultural Research Council, Onderstepoort 0110 (South Africa); Ribeiro, Jose M. C.; Andersen, John F., E-mail: jandersen@niaid.nih.gov [NIH/NIAID, 12735 Twinbrook Parkway, Rockville, MD 20852 (United States)

    2013-01-01

    Biogenic amine-binding proteins mediate the anti-inflammatory and antihemostatic activities of blood-feeding insect saliva. The structure of the amine-binding protein from R. prolixus reveals the interaction of biogenic amine ligands with the protein. Proteins that bind small-molecule mediators of inflammation and hemostasis are essential for blood-feeding by arthropod vectors of infectious disease. In ticks and triatomine insects, the lipocalin protein family is greatly expanded and members have been shown to bind biogenic amines, eicosanoids and ADP. These compounds are potent mediators of platelet activation, inflammation and vascular tone. In this paper, the structure of the amine-binding protein (ABP) from Rhodnius prolixus, a vector of the trypanosome that causes Chagas disease, is described. ABP binds the biogenic amines serotonin and norepinephrine with high affinity. A complex with tryptamine shows the presence of a binding site for a single ligand molecule in the central cavity of the β-barrel structure. The cavity contains significant additional volume, suggesting that this protein may have evolved from the related nitrophorin proteins, which bind a much larger heme ligand in the central cavity.

  16. Structure and ligand-binding properties of the biogenic amine-binding protein from the saliva of a blood-feeding insect vector of Trypanosoma cruzi

    International Nuclear Information System (INIS)

    Xu, Xueqing; Chang, Bianca W.; Mans, Ben J.; Ribeiro, Jose M. C.; Andersen, John F.

    2013-01-01

    Biogenic amine-binding proteins mediate the anti-inflammatory and antihemostatic activities of blood-feeding insect saliva. The structure of the amine-binding protein from R. prolixus reveals the interaction of biogenic amine ligands with the protein. Proteins that bind small-molecule mediators of inflammation and hemostasis are essential for blood-feeding by arthropod vectors of infectious disease. In ticks and triatomine insects, the lipocalin protein family is greatly expanded and members have been shown to bind biogenic amines, eicosanoids and ADP. These compounds are potent mediators of platelet activation, inflammation and vascular tone. In this paper, the structure of the amine-binding protein (ABP) from Rhodnius prolixus, a vector of the trypanosome that causes Chagas disease, is described. ABP binds the biogenic amines serotonin and norepinephrine with high affinity. A complex with tryptamine shows the presence of a binding site for a single ligand molecule in the central cavity of the β-barrel structure. The cavity contains significant additional volume, suggesting that this protein may have evolved from the related nitrophorin proteins, which bind a much larger heme ligand in the central cavity

  17. [Entomological study of Trypanosoma cruzi vectors in the rural communities of Sucre state, Venezuela].

    Science.gov (United States)

    García-Jordán, Noris; Berrizbeitia, Mariolga; Concepción, Juan Luis; Aldana, Elis; Cáceres, Ana; Quiñones, Wilfredo

    2015-01-01

    The ecological niche of Reduvidae vectors has been modified due to environmental changes and human encroachment into the rural areas. This study evaluates the current entomological indices of triatomines responsible for Trypanosoma cruzi infection in Sucre State, Venezuela. A cross-sectional and prospective study was conducted in 95 towns and 577 dwellings in the 15 municipalities of the state of Sucre, Venezuela, from August to November, 2008. Triatomine bugs were identified on the basis of morphological characteristics, and their feces examined for T. cruzi infection through direct microscopy. Positive slides were stained with Giemsa and parasites were identified by morphologic characterization. The entomological indices expressing the highest values were dispersion (16.67%) and household colonization (33.33%). The triatomine species captured were: Rhodnius prolixus , Rhodnius main intradomiciliary vector. Despite the low index of vector infection (1.72%), the existence of species with domiciliary and peridomiciliary reproductive success ensures the persistence of the epidemiological chain both for the disease and the parasite.

  18. 2-DE-based proteomic investigation of the saliva of the Amazonian triatomine vectors of Chagas disease: Rhodnius brethesi and Rhodnius robustus

    DEFF Research Database (Denmark)

    Costa, Camila M; Sousa, Marcelo V; Ricart, Carlos André O

    2011-01-01

    The triatomine bugs are obligatory haematophagous organisms that act as vectors of Chagas disease by transmitting the protozoan Trypanosoma cruzi. Their feeding success is strongly related to salivary proteins that allow these insects to access blood by counteracting host haemostatic mechanisms...

  19. Estudo comparativo do ciclo evolutivo de Rhodnius neglectus alimentados em pombos ou camundongos

    Directory of Open Access Journals (Sweden)

    Liléia Diotaiuti

    1987-06-01

    Full Text Available Baseados no encontro de 77,2% de reação de precipitina positiva para soro antiave de R. neglectus capturados em palmeiras da periferia de Belo Horizonte, estudamos o ciclo evolutivo de uma colonia recém-estabelecida no laboratório alimentada com sangue de pombo ou camundongo, na expectativa de demonstrarmos maior adaptação deste triatomíneo ao sangue da ave. Para comparação, estudamos o ciclo evolutivo destes insetos numa colônia há muito mantida em insetário. Nossos resultados mostram um desenvolvimento mais rápido da colônia recém- estabelecida, assim como do lote de triatomíneos alimentado em camundongo. Esses achados sugerem menor potencial biológico para triatomíneos criados por longo tempo em insetário em comparação a novas colônias. Sendo as aves os principais habitantes das palmeiras, a aparente preferência alimentar por sangue de aves demonstrada pela reação de precipitina parece ser circunstancial e não seletiva na busca do sangue com o qual o triatomíneo obteria melhor desenvolvimento.Feeding pattems of R. neglectus collected in palm trees around Belo Horizonte (Minas Gerais, Brazil were investigated. Precipitin tests showed 77.2% of avian blood. In view of these results, a new colony of R. neglectus established in the laboratory was fed regularly on pigeons or mice, in order to verify a possible better adaptation of this insect to the avian blood. As a control group a colony of R neglectus which has been maintained for several years in the laboratory was also observed. The results show a better development of the “new" colony in comparison with the old one, and of those bugs nourished with mice blood. Such findings suggest a poorer biological potential for triatomines maintained for long time in artificial conditions, in comparison with those living in the natural environment. As birds are the main vertebrate inhabitants of palm trees (the natural ecotope of R neglectus, the apparent feeding preference of this species for avian blood seems to be merely circumstancial and not related to a better biological performance provided by this kind of blood.

  20. Ductile austenitic steel for fuel cans and core components of sodium cooled reactors; Ein duktiler austenitischer Stahl fuer Huellrohre und Kernkomponenten natriumgekuehlter Brueter

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, L.

    1995-08-01

    Two austenitic steel melts of a new composition have been studied after irradiation in the PFR fast neutron flux, in the BR2 reactor, and in the Harwell V.E. Cyclotron. The investigations were focussed on helium embrittlement and irradiation induced swelling. (orig.)

  1. KS R41B. A high performance steel-aluminium composite material; KS R41B. Ein Stahl-Aluminium-Verbundwerkstoff fuer hohe Belastungen

    Energy Technology Data Exchange (ETDEWEB)

    Deicke, K. [KS Gleitlager GmbH (Germany). Bereich Metall; Matucha, H.; Schubert, W. [KS Gleitlager GmbH, St. Leon-Rot (Germany); Steffens, T. [KS Gleitlager GmbH, Neckarsulm (Germany)

    2002-08-01

    Aluminium-tin alloys have been well-known for a long time and have proved to be suitable bearing materials for crankshaft bearings for many years. The known alloy AlZn4,5SiCuPb is one of the aluminium materials capable of sustaining the highest mechanical loads. In order to achieve optimum sliding properties, it would be necessary to increase the share of the soft lead phase in the alloy. This article by KS Gleitlager GmbH shows a reasonably priced manufacturing technology for high-performance aluminium-zinc-silicon-copper alloys. (orig.) [German] Die Aluminium-Zinn-Lagerlegierungen sind seit langem bekannt und haben sich seit Jahren als Lagerwerkstoff fuer Kurbelwellenlager bewaehrt. Die Legierung AlZn4,5SiCuPb gehoert zu den mechanisch am hoechsten belastbaren Aluminium-Werkstoffen. Um optimale Gleiteigenschaften zu erzielen, muesste in der Legierung der Anteil des weichen Bleis noch weiter erhoeht werden. Dieser Beitrag der KS Gleitlager GmbH zeigt eine kostenguenstige Herstelltechnologie fuer hochbelastbare Aluminium-Zink-Silizium-Kupfer-Legierungen. (orig.)

  2. Steel, hard metal and diamonds. The history of drilling blast holes in mining and tunneling; Stahl, Hartmetall und Diamanten. Zur Geschichte des Sprenglochbohrens im Berg- und Tunnelbau

    Energy Technology Data Exchange (ETDEWEB)

    Feistkorn, E. [Inst. fuer Vortrieb und Gewinnung, DMT-Gesellschaft fuer Forschung und Pruefung mbH, Essen (Germany)

    1997-12-31

    Beginning of the blasting technique in mining and tunneling during the 17th century required drilling holes to take the explosive. Following the use of hammer and wedge, drilling was done over a long period of time by hand with mallet and drillsteel. Continuously, during the 19th century the handwork was replaced by drilling machines. Technically, the evolution of drilling equipment is marked by electrohydraulic control and automatization with the assistance of microelectronics. Regarding the material, the introduction of hard metal and - in addition for rotary drilling - the development of synthetic diamond material are the main features. (orig.) [Deutsch] Mit der Einfuehrung der Sprengtechnik im Bergbau und Tunnelbau im 17. Jahrhundert mussten verfahrensbedingt Bohrloecher zur Aufnahme des Sprengstoffes hergestellt werden. In Anlehnung an die Arbeit mit Schlaegel und Eisen erfolgte dies lange Zeit manuell mit dem Bohrfaeustel und Stahlbohrern. Die Handarbeit wurde waehrend der 2. Haelfte des 19. Jahrhunderts kontinuierlich durch Bohrmaschinen verdraengt. Maschinentechnisch ist die weitere Entwicklung durch elektrohydraulische Steuerungen und die Automatisierung der Bohrgeraete mit Hilfe der Mikroelektronik gekennzeichnet. Materialtechnisch stellen die Einfuehrung des Hartmetalls und beim drehenden Bohren zusaetzlich die Entwicklung synthetischer Diamantwerkstoffe die herausragenden Marksteine dar. (orig.)

  3. Zum zeitabhängigen Verhalten elektrochemischer und morphologischer Kenngrößen bei der chloridinduzierten Korrosion von Stahl in Beton

    OpenAIRE

    Harnisch, Jörg

    2012-01-01

    It is an undeniable fact that the number of chloride induced corrosion damages in reinforced concrete structures has increased considerably during the last decades. In the context of actual scientific efforts regarding the modelling of chloride induced corrosion phenomena of steel in concrete this thesis aims at the analysis of the time dependent behaviour of electro-chemical and morphological parameters of the macro-cell anode being the location of active metal dissolution. As a result of el...

  4. Measurement of hydrogen distributions in iron and steel by means of neutron radiography and tomography; Messung von Wasserstoffverteilungen in Eisen und Stahl mittels Neutronenradiographie und -tomographie

    Energy Technology Data Exchange (ETDEWEB)

    Griesche, Axel; Kannengiesser, Thomas [BAM Bundesanstalt fuer Materialforschung und -pruefung, Berlin (Germany); Kardjilov, Nikolay; Manke, Ingo [Helmholtz-Zentrum Berlin (HZB), Berlin (Germany); Schillinger, Burkhard [Technische Univ. Muenchen, Garching (Germany)

    2015-07-01

    In recent years, the optimization of the radiography measuring stations at research reactors and in particular the development of the neutron detectors has enabled the measurement of hydrogen distributions with ever higher spatial resolution at the same time more sensitive detection limit. Compared to iron, hydrogen has a high interaction cross-section for neutrons, and thus allows simple radiographic methods of the two and three dimensional visualization of hydrogen distribution in the structure. This allowed us for the first time the measurement of hydrogen diffusion flows in centimeter-thick steel samples with a temporal resolution of 20 s and the quantitative measurement of hydrogen accumulation of crack edges in hydrogen embrittled iron samples. It was also the first gaseous hydrogen detected in the cavities of the cracks and the pressure can be determined. This new quality of information on the microstructure scale granted unprecedented insights for the investigation of damage mechanisms e.g. in the hydrogen embrittlement. By providing local in-situ information that is not accessible by conventional methods such as carrier gas hot extraction, as well as analyzes can be performed in three dimensions with a spatial resolution of 20-30 μm. This article provides examples that use the spatial and temporal resolution of the neutron radiography and tomography to visualize hydrogen distributions in and around cracks and to quantify. The measurements were conducted at the research reactors BER II of HZB in Berlin and FRM II of teh neutron source Heinz Maier-Leibnitz in Garching. (This article contains PowerPoint slides). [German] In den letzten Jahren hat die Optimierung der Radiographie-Messplaetze an Forschungsreaktoren und hier insbesondere die Weiterentwicklung der Neutronendetektoren die Messung von Wasserstoffverteilungen mit immer hoeherer Ortsaufloesung bei gleichzeitig empfindlicherer Nachweisgrenze ermoeglicht. Wasserstoff besitzt im Vergleich zu Eisen einen hohen Wechselwirkungsquerschnitt fuer Neutronen und erlaubt somit mit einfachen radiographischen Methoden die zwei- und dreidimensionale Visualisierung von Wasserstoffverteilungen im Gefuege. Dies ermoeglichte uns erstmals die Messung von Wasserstoffdiffusionsstroemen in zentimeterdicken Stahlproben mit einer zeitlichen Aufloesung von 20 s sowie die quantitative Messung von Wasserstoffansammlungen an Rissflanken in wasserstoffversproedeten Eisenproben. Dabei konnte auch erstmals gasfoermiger Wasserstoff in den Hohlraeumen der Risse nachgewiesen werden und dessen Druck bestimmt werden. Diese neue Qualitaet der Information auf der Mikrostrukturskala gewaehrt noch nie dagewesene Einblicke fuer die Aufklaerung von Schaedigungsmechanismen z. B. bei der Wasserstoffversproedung. Durch die Bereitstellung von lokalen in situ Informationen, die mit herkoemmlichen Methoden wie der Traegergas-Heissextraktion nicht zugaenglich sind, koennen so auch Analysen in drei Dimensionen mit einer Ortsaufloesung von 20-30 μm durchgefuehrt werden. In diesem Beitrag werden Beispiele gezeigt, die die Orts- und Zeitaufloesung der Neutronenradiographie und -tomographie nutzen, um Wasserstoffverteilungen in und an Rissen zu visualisieren und zu quantifizieren. Die Messungen wurden an den Forschungsreaktoren BER II des HZB in Berlin und FRM II der Neutronenquelle Heinz Maier-Leibnitz in Garching durchgefuehrt.

  5. Epidemiología de la enfermedad de Chagas en el municipio Andrés Eloy Blanco, Lara, Venezuela: infestación triatomínica y seroprevalencia en humanos Epidemiology of Chagas disease in Andrés Eloy Blanco, Lara, Venezuela: triatomine infestation and human seroprevalence

    Directory of Open Access Journals (Sweden)

    Claudina Rodríguez-Bonfante

    2007-05-01

    Full Text Available Se realizó un despistaje serológico y recolección de vectores en cuatro comunidades rurales del municipio Andrés Eloy Blanco, Estado Lara, Venezuela. La muestra fue escogida en forma sistemática y aleatoria basada en conglomerados familiares. Se muestrearon 869 habitantes para determinar anticuerpos anti-Trypanosoma cruzi y anti-Leishmania sp. por inmunofluorescencia indirecta, aceptando como positivo diluciones > a 1:32 para anticuerpos anti-T. cruzi no reactivos para antígenos de Leishmania sp., obteniendo una frecuencia de anticuerpos en la muestra de 6,9% (n = 60; de los cuales 46,66% son femeninos, 53,33% masculinos y 60% mayores de 40 años. Se observó que 5 (8,33% de los seropositivos eran menores de 10 años y 10 (16,66% menores de 20 años. Rhodnius prolixus y Panstrongylus geniculatus fueron los triatominos capturados, con índice de infestación de 1,9 y 10,54%, índice de colonización, del 0 y 18,18% en las viviendas infestadas e índice de infección a T. cruzi del 20 y 5,07%, respectivamente. Los resultados sugieren que existe una transmisión activa de la enfermedad de Chagas en el Municipio Andrés Eloy Blanco en las últimas dos décadas y que P. geniculatus está substituyendo a R. prolixus como vector de la enfermedad de Chagas.A seroepidemiological survey and vector captures were performed in four rural communities in Andrés Eloy Blanco, Lara State, Venezuela. Systematic random sampling was based on family clusters, with samples drawn from 869 individuals to determine anti-Trypanosoma cruzi and anti-Leishmania sp. antibodies by indirect immunofluorescence. Positive individuals were defined as > 1:32 for anti-T. cruzi antibody and non-reactive to Leishmania sp. antigen, revealing an antibody frequency of 6.9% (n = 60, of whom 46.66% were females and 53.33% males and 60% were over 39 years of age. Some 5 (8.33% seropositive individuals were under 10 years of age and 10 (16.66% under 20 years. Rhodnius prolixus and

  6. Febre maculosa das Montanhas Rochosas: ensaios negativos de transmissão experimental do virus por Triatomideos Rocky Mountain spotted fever: failure of Triatomid bugs to transmit the virus experimentally

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    Cornelius B. Philip

    1938-01-01

    Full Text Available 1. - As seguintes especies de Triatomideos não puderam transmitir pela picada o virus da febre maculosa das Montanhas Rochosas a cobayas normaes, nos seguintes prazos após a sucção de animal infectado: Eutriatoma uhleri, 33, 47, 75 e 141 dias (1 exemplar; Triatoma protracta, 15 e 37 dias (1 exemplar, Triatoma infestans, 8 dias (15 exemplares, e Rhodnius prolixus, 2 dias (1 exemplar. Foi demonstrado por inoculaçao que o ultimo insecto ainda continha o virus vivo. 2. - Experiencias de transmissão mechanica, por picada interrompida em animal infectado e continuada immediatamente em animal são, foram tambem negativas, com as especies T. protracta e R. prolixus. Um unico insecto da primeira especie picou 2 vezes cada animal, emquanto que 22 exemplares da segunda especie picaram de 1 a 3 vezes cada cobaya. 3. - A inoculação de gottas de dejecções de um R. prolixus eliminadas 2 dias depois de sugar animal infectado, não produziu a infecção em cobaya normal, não obstante ter sido demonstrada a presença do virus no organismo do barbeiro, por inoculação do conteúdo estomacal em outra cobaya. 4. - Foram feitas experiencias para determinar o tempo de sobrevivencia do virus nos barbeiros, inoculando-se conteúdo intestinal a diversos intervallos depois da sucção de cobayas infectadas, com os seguintes resultados: T. infestans: positivo 1 vez em 24 horas e 2 vezes em 48 horas; negativo 2 vezes em 72. 96, 120 e 192 horas. P. megistus: positivo 3 vezes em 24 horas, 2 vezes em 48 horas e 1 vez em 72 horas; negativo 1 vez em 72 e 96 horas; resultado duvidoso ou sem valor (infecção intercorrente 1 vez em 48 horas e 2 vezes a 72, 96 e 144 horas cada um. R. prolixus: positivo 1 vez em 24, 48 e 72 horas e negativo em 96 horas. 5. - Em vista dos resultados destas experiencias, feitas com 5 especies pertecentes a 4 generos de Triatomideos, torna-se muito pouco provavel que estes Hemipteros possam transmitir pela picada o virus da febre maculosa

  7. Screening of Fungi for Biological Control of a Triatomine Vector of Chagas Disease: Temperature and Trypanosome Infection as Factors.

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    Aline R M Garcia

    2016-11-01

    Full Text Available Entomopathogenic fungi have been investigated as an alternative tool for controlling various insects, including triatomine vectors of the protozoan Trypanosoma cruzi, the etiological agent of Chagas disease. Here we tested the pathogenicity and virulence of ten isolates of the fungi Metarhizium spp. and Beauveria bassiana against Rhodnius prolixus and found all of the isolates to be virulent. We used two isolates (URPE-11 Metarhizium anisopliae and ENT-1 Beauveria bassiana for further screening based on their prolific sporulation in vitro (an important property of fungal biopesticides. We characterized their virulences in a dose-response experiment and then examined virulence across a range of temperatures (21, 23, 27 and 30°C. We found isolate ENT-1 to maintain higher levels of virulence over these temperatures than URPE-11. We therefore used B. bassiana ENT-1 in the final experiment in which we examined the survival of insects parasitized with T. cruzi and then infected with this fungus (once again over a range of temperatures. Contrary to our expectations, the survival of insects challenged with the pathogenic fungus was greater when they had previously been infected with the parasite T. cruzi than when they had not (independent of temperature. We discuss these results in terms of aspects of the biologies of the three organisms. In practical terms, we concluded that, while we have fungal isolates of potential interest for development as biopesticides against R. prolixus, we have identified what could be a critical problem for this biological tool: the parasite T. cruzi appears to confer a measure of resistance to the insect against the potential biopesticide agent so use of this fungus as a biopesticide could lead to selection for vector competence.

  8. Insecticide resistance in vector Chagas disease: evolution, mechanisms and management.

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    Mougabure-Cueto, Gastón; Picollo, María Inés

    2015-09-01

    Chagas disease is a chronic parasitic infection restricted to America. The disease is caused by the protozoa Trypanosoma cruzi, which is transmitted to human through the feces of infected triatomine insects. Because no treatment is available for the chronic forms of the disease, vector chemical control represents the best way to reduce the incidence of the disease. Chemical control has been based principally on spraying dwellings with insecticide formulations and led to the reduction of triatomine distribution and consequent interruption of disease transmission in several areas from endemic region. However, in the last decade it has been repeatedly reported the presence triatomnes, mainly Triatoma infestans, after spraying with pyrethroid insecticides, which was associated to evolution to insecticide resistance. In this paper the evolution of insecticide resistance in triatomines is reviewed. The insecticide resistance was detected in 1970s in Rhodnius prolixus and 1990s in R. prolixus and T. infestans, but not until the 2000s resistance to pyrthroids in T. infestans associated to control failures was described in Argentina and Bolivia. The main resistance mechanisms (i.e. enhanced metabolism, altered site of action and reduced penetration) were described in the T. infestans resistant to pyrethrods. Different resistant profiles were demonstrated suggesting independent origin of the different resistant foci of Argentina and Bolivia. The deltamethrin resistance in T. infestans was showed to be controlled by semi-dominant, autosomally inherited factors. Reproductive and developmental costs were also demonstrated for the resistant T. infestans. A discussion about resistance and tolerance concepts and the persistence of T. infestans in Gran Chaco region are presented. In addition, theoretical concepts related to toxicological, evolutionary and ecological aspects of insecticide resistance are discussed in order to understand the particular scenario of pyrethroid

  9. NMR Studies of the Dynamics of Nitrophorin 2 Bound to Nitric Oxide†

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    Muthu, Dhanasekaran; Berry, Robert E.; Zhang, Hongjun; Walker, F. Ann

    2013-01-01

    The Rhodnius nitrophorins are β-barrel proteins of the lipocalin fold with a heme protruding from the open end of the barrel. They are found in the saliva of the blood-sucking insect Rhodnius prolixus, which synthesizes and stores nitric oxide (NO) in the salivary glands, where NO is bound to iron. NO is released by dilution and pH rise when the insect spits its saliva into the tissues of a victim, to aid in obtaining a blood meal. In the adult insect there are four nitrophorins, NP1, NP2, NP3 and NP4. At pH 7.3, NP4 releases NO 17 times faster than does NP2, as measured by stopped-flow kinetics. A number of crystal structures of the least abundant protein, NP4, are available. These structures have been used to propose that two loops between adjacent β-strands at the front opening of the protein, the A-B and G-H loops, determine the rate of NO release. In order to learn how the protein loops contribute to release of NO for each of the nitrophorins, the dynamics of these proteins are being studied in our laboratory. In this work, the NP2-NO complex has been investigated by NMR relaxation measurements to probe the pico- to nanosecond and micro- to millisecond time scale motions at three pH values, 5.0, 6.5, and 7.3. It is found that at pH 5.0 and 6.5, NP2-NO is rigid and only a few residues in the loop regions show dynamics, while at pH 7.3 somewhat more dynamics, particularly of the A-B loop, are observed. Comparison to other lipocalins shows that all are relatively rigid, and that the dynamics of lipocalins in general are much more subtle than those of mainly α-helical proteins. PMID:24116947

  10. Cardiac contractility structure-activity relationship and ligand-receptor interactions; the discovery of unique and novel molecular switches in myosuppressin signaling.

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    Megan Leander

    Full Text Available Peptidergic signaling regulates cardiac contractility; thus, identifying molecular switches, ligand-receptor contacts, and antagonists aids in exploring the underlying mechanisms to influence health. Myosuppressin (MS, a decapeptide, diminishes cardiac contractility and gut motility. Myosuppressin binds to G protein-coupled receptor (GPCR proteins. Two Drosophila melanogaster myosuppressin receptors (DrmMS-Rs exist; however, no mechanism underlying MS-R activation is reported. We predicted DrmMS-Rs contained molecular switches that resembled those of Rhodopsin. Additionally, we believed DrmMS-DrmMS-R1 and DrmMS-DrmMS-R2 interactions would reflect our structure-activity relationship (SAR data. We hypothesized agonist- and antagonist-receptor contacts would differ from one another depending on activity. Lastly, we expected our study to apply to other species; we tested this hypothesis in Rhodnius prolixus, the Chagas disease vector. Searching DrmMS-Rs for molecular switches led to the discovery of a unique ionic lock and a novel 3-6 lock, as well as transmission and tyrosine toggle switches. The DrmMS-DrmMS-R1 and DrmMS-DrmMS-R2 contacts suggested tissue-specific signaling existed, which was in line with our SAR data. We identified R. prolixus (RhpMS-R and discovered it, too, contained the unique myosuppressin ionic lock and novel 3-6 lock found in DrmMS-Rs as well as transmission and tyrosine toggle switches. Further, these motifs were present in red flour beetle, common water flea, honey bee, domestic silkworm, and termite MS-Rs. RhpMS and DrmMS decreased R. prolixus cardiac contractility dose dependently with EC50 values of 140 nM and 50 nM. Based on ligand-receptor contacts, we designed RhpMS analogs believed to be an active core and antagonist; testing on heart confirmed these predictions. The active core docking mimicked RhpMS, however, the antagonist did not. Together, these data were consistent with the unique ionic lock, novel 3-6 lock

  11. Estrategia para determinar la línea base en áreas de interrupción vectorial de la enfermedad de Chagas

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    Diego Montenegro

    Full Text Available RESUMEN Objetivos Presentar una estrategia para determinar la línea de base en áreas endémicas en el proceso de interrupción vectorial de la enfermedad de Chagas (ECh. Métodos Con un cuestionario socioambiental y una encuesta entomológica, se evaluaron las condiciones físicas de los domicilios, el conocimiento de los habitantes sobre la ECh, los indicadores entomológicos de triatominos y la relación estadística entre estas variables. Resultados Existe colonización e infección natural con Trypanosoma cruzi en Rhodnius prolixus, el principal vector de la ECh en Colombia. La colonización estuvo relacionada con casas de techos de hojas de palma y paredes de adobe o bahareque. Se encontró el vector Panstrongylus geniculatus con hábitos de colonización. Casi 50% de la población encuestada asociaba el término ECh con una enfermedad humana y 37%, con los triatominos. Conclusiones R. prolixus puede considerarse el principal vector de T. cruzi en ambientes domésticos y el proceso de interrupción vectorial es factible dentro del municipio priorizado. Se necesitan nuevos estudios que comprueben la existencia de poblaciones silvestres de R. prolixus que puedan afectar las etapas futuras del proceso y demostrar si hay una participación de P. geniculatus en la dinámica de transmisión de T. cruzi. Los anteriores escenarios pueden ser viabilizados con la inclusión de los habitantes en todo el proceso, ya que han sido altamente sensibles en la detección de vectores dentro de sus casas. El diseño del estudio aquí presentado puede ser adaptado en otras áreas endémicas de la Región de las Américas.

  12. Distribution and activity of a Dippu DH31-like peptide in the large milkweed bug Oncopeltus fasciatus.

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    Te Brugge, V A; Orchard, I

    2008-02-01

    The milkweed bug, Oncopeltus fasciatus, is a plant feeding hemipteran. While there has been much research done on the neurohormonal control of the post-feeding diuresis in the blood-feeding hemipteran, Rhodnius prolixus, little is known about the control of the post-feeding diuresis in O. fasciatus. One of the neurohormones that may play a role in this rapid diuresis belongs to the calcitonin-like diuretic hormone (DH31) family of insect peptides. In this study we demonstrate the presence of DH31-like immunoreactivity in the central nervous system (CNS) and gut of O. fasciatus 5th instars. As well, DH31-like material was quantified and partially purified from the CNS of 5th instar O. fasciatus using reversed-phase liquid chromatography (RPLC) and monitored with an enzyme-linked immunosorbent assay (ELISA). When tested on O. fasciatus 5th instar Malpighian tubules, DH31-like peptides significantly increased the rate of secretion over saline controls. The results suggest that there is a DH31-like peptide(s) present in the CNS of O. fasciatus and that this peptide may play a role in the control of Malpighian tubule secretion.

  13. Geographic distribution and morphometric differentiation of Triatoma nitida usinger 1939 (Hemiptera: Reduviidae: Triatominae in Guatemala

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    Monroy Carlota

    2003-01-01

    Full Text Available Triatoma nitida was found in 14 (0.4% out of 3,726 houses located in six departments across Guatemala, which were surveyed from 1994 to 1998 by the man-hour collection method. Compared to previous information, the distribution of T. nitida in Guatemala has increased from five to nine departments; the species is present in mild climates at altitudes from 960 to 1,500 m. Fourteen percent of the intradomestic T. nitida were infected with Trypanosoma cruzi. The species was often found in conjunction with other triatomines (T. dimidiata and Rhodnius prolixus. The domestic and peridomestic presence of T. nitida in Guatemala was rare, but occasionally this species was colonizing human-made constructions. T. nitida appears to have a low importance as Chagas disease vector in Guatemala, as indicated by its scarce presence in the domestic habitats and defecation patterns. However, it clearly has potential to become a Chagas vector so we recommend an on-going study of the intradomestic presence of T. nitida following the control programs in Guatemala. Morphometric analysis of 47 T. nitida males from three localities showed quantitative differences between the populations, which indicates that geographic distance is an important factor in the structuring of T. nitida populations.

  14. Anti-complement activity in the saliva of phlebotomine sand flies and other haematophagous insects.

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    Cavalcante, R R; Pereira, M H; Gontijo, N F

    2003-07-01

    The saliva of haematophagous insects has a series of pharmacological activities which may favour blood feeding. In the present study, an inhibitory effect on the complement system was observed in salivary extracts obtained from the phlebotomine sand flies Lutzomyia longipalpis and Lu. migonei. Saliva from Lu. longipalpis was capable of inhibiting both the classical and alternative pathways, while that from Lu. migonei acted only on the former. Other haematophagous insect species were screened for inhibition of the classical pathway. The triatomine bugs Panstrongylus megistus, Triatoma brasiliensis and Rhodnius prolixus were also able to inhibit the classical pathway whereas the mosquito Aedes aegyti and flea Ctenocephalides felis were not. The activity of Lu. longipalpis saliva on the classical pathway was partially characterized. The inhibitor is a protein of Mr 10000-30000 Da, which is very resistant to denaturation by heat. The inhibition of the complement system by phlebotomine sand flies may have a role in the transmission of Leishmania to the vertebrate hosts. The inhibitor molecule is thus a promising component of a vaccine to target salivary immunomodulators.

  15. A revision of thirteen species of Triatominae (Hemiptera: Reduviidae vectors of Chagas disease in Mexico

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    Salazar-Schettino Paz Maria

    2010-10-01

    Full Text Available Vectors of Trypanosoma cruzi, parasite responsible for Chagas disease, are divided in intradomestic, peridomestic and sylvatic. The intradomestic are Triatoma barberi and Triatoma dimidiata, two species that represent the highest health risk among the Mexican population. Triatoma dimidiata is a species found mainly inside human habitats, but in Yucatan, it corresponds to the peridomicile vectors. Also in the peridomicile most of Chagas disease vectors are found: Meccus bassolsae, M. longipennis, M. mazzottii, M pallidipennis, M. phyllosomus, M picturata, Triatoma gerstaeckeri, T mexicana, T rubida, Dipetalogaster máxima (the last two are in the process of becoming adapted to the domicile, Panstrongylus rufotuberculatus which occasionally enters the domicile in its adult stage, and Rhodnius prolixus, which is practically controlled in the country. Peridomestic vectors are of lower risk in the transmission dynamics, as compared to the intradomestic ones. For the control of the intradomestic vectors, health education programs, improvements of housing, and the use of pesticides are essential To control the peridomestic vectors, health education programs are required, as well as the use of mosquito nets on doors and windows and around beds, aside from cementing the stone wall fences.

  16. Uso de nuevas herramientas para el control de triatominos en diferentes situaciones entomológicas en el continente americano

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    Oliveira Filho Alfredo M.

    1997-01-01

    Full Text Available Se relatan los resultados obtenidos en el terreno seis meses y dos años post-tratamiento con las nuevas herramientas para el control de triatominos desarrolladas con apoyo de la OMS/TDR, o sea, a pinturas insecticidas, una suspensión emulsionable de lenta liberación conteniendo el 8,3% de malathion, aplicada por rociamiento; b potes fumígenos que, después de encendidos, echan humos que contienen cypermetrina y DDVP; c cajas sensoras para detección de triatominos. Los ensayos en el terreno fueron realizados en Chile, Honduras y Paraguay contra tres especies principales de vectores de la enfermedad de Chagas - Triatoma infestans, T. dimidiata y Rhodnius prolixus, según el protocolo elaborado por un comité de expertos de la OMS. Los resultados indican que las pinturas insecticidas constituyen un eficaz medio de control de estos vectores en cualquiera de las condiciones estudiadas, sea en el domicilio, sea en el peridomicilio, manteniendo los porcentajes de infestación muy próximos a cero. Comparaciones preliminares de la técnica de cajas sensoras para detección de casas infestadas por triatominos, con la búsqueda hecha por personal entrenado (hora/hombre indican esta última como la mas apropiada.

  17. Substrate texture properties induce triatomine probing on bitten warm surfaces

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    Lorenzo Marcelo G

    2011-06-01

    Full Text Available Abstract Background In this work we initially evaluated whether the biting process of Rhodnius prolixus relies on the detection of mechanical properties of the substrate. A linear thermal source was used to simulate the presence of a blood vessel under the skin of a host. This apparatus consisted of an aluminium plate and a nickel-chrome wire, both thermostatized and presented at 33 and 36°C, respectively. To evaluate whether mechanical properties of the substrate affect the biting behaviour of bugs, this apparatus was covered by a latex membrane. Additionally, we evaluated whether the expression of probing depends on the integration of bilateral thermal inputs from the antennae. Results The presence of a latex cover on a thermal source induced a change in the biting pattern shown by bugs. In fact, with latex covered sources it was possible to observe long bites that were never performed in response to warm metal surfaces. The total number of bites was higher in intact versus unilaterally antennectomized insects. These bites were significantly longer in intact than in unilaterally antennectomized insects. Conclusions Our results suggest that substrate recognition by simultaneous input through thermal and mechanical modalities is required for triggering maxillary probing activity.

  18. Lysophosphatidylcholine: A Novel Modulator of Trypanosoma cruzi Transmission

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    Mário A. C. Silva-Neto

    2012-01-01

    Full Text Available Lysophosphatidylcholine is a bioactive lipid that regulates a large number of cellular processes and is especially present during the deposition and infiltration of inflammatory cells and deposition of atheromatous plaque. Such molecule is also present in saliva and feces of the hematophagous organism Rhodnius prolixus, a triatominae bug vector of Chagas disease. We have recently demonstrated that LPC is a modulator of Trypanosoma cruzi transmission. It acts as a powerful chemoattractant for inflammatory cells at the site of the insect bite, which will provide a concentrated population of cells available for parasite infection. Also, LPC increases macrophage intracellular calcium concentrations that ultimately enhance parasite invasion. Finally, LPC inhibits NO production by macrophages stimulated by live T. cruzi, and thus interferes with the immune system of the vertebrate host. In the present paper, we discuss the main signaling mechanisms that are likely used by such molecule and their eventual use as targets to block parasite transmission and the pathogenesis of Chagas disease.

  19. Mitochondrial dysfunction in Trypanosoma cruzi: the role of Serratia marcescens prodigiosin in the alternative treatment of Chagas disease

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    Triana Omar

    2011-05-01

    Full Text Available Abstract Background Chagas disease is a health threat for many people, mostly those living in Latin America. One of the most important problems in treatment is the limitation of existing drugs. Prodigiosin, produced by Serratia marcescens (Rhodnius prolixus endosymbiont, belongs to the red-pigmented bacterial prodiginine family, which displays numerous biological activities, including antibacterial, antifungal, antiprotozoal, antimalarial, immunosuppressive, and anticancer properties. Here we describe its effects on Trypanosoma cruzi mitochondria belonging to Tc I and Tc II. Results Parasites exposed to prodigiosin altered the mitochondrial function and oxidative phosphorylation could not have a normal course, probably by inhibition of complex III. Prodigiosin did not produce cytotoxic effects in lymphocytes and Vero cells and has better effects than benznidazole. Our data suggest that the action of prodigiosin on the parasites is mediated by mitochondrial structural and functional disruptions that could lead the parasites to an apoptotic-like cell death process. Conclusions Here, we propose a potentially useful trypanocidal agent derived from knowledge of an important aspect of the natural life cycle of the parasite: the vector-parasite interaction. Our results indicate that prodigiosin could be a good candidate for the treatment of Chagas disease.

  20. Catalase expression impairs oxidative stress-mediated signalling in Trypanosoma cruzi.

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    Freire, Anna Cláudia Guimarães; Alves, Ceres Luciana; Goes, Grazielle Ribeiro; Resende, Bruno Carvalho; Moretti, Nilmar Silvio; Nunes, Vinícius Santana; Aguiar, Pedro Henrique Nascimento; Tahara, Erich Birelli; Franco, Glória Regina; Macedo, Andréa Mara; Pena, Sérgio Danilo Junho; Gadelha, Fernanda Ramos; Guarneri, Alessandra Aparecida; Schenkman, Sergio; Vieira, Leda Quercia; Machado, Carlos Renato

    2017-09-01

    Trypanosoma cruzi is exposed to oxidative stresses during its life cycle, and amongst the strategies employed by this parasite to deal with these situations sits a peculiar trypanothione-dependent antioxidant system. Remarkably, T. cruzi's antioxidant repertoire does not include catalase. In an attempt to shed light on what are the reasons by which this parasite lacks this enzyme, a T. cruzi cell line stably expressing catalase showed an increased resistance to hydrogen peroxide (H2O2) when compared with wild-type cells. Interestingly, preconditioning carried out with low concentrations of H2O2 led untransfected parasites to be as much resistant to this oxidant as cells expressing catalase, but did not induce the same level of increased resistance in the latter ones. Also, presence of catalase decreased trypanothione reductase and increased superoxide dismutase levels in T. cruzi, resulting in higher levels of residual H2O2 after challenge with this oxidant. Although expression of catalase contributed to elevated proliferation rates of T. cruzi in Rhodnius prolixus, it failed to induce a significant increase of parasite virulence in mice. Altogether, these results indicate that the absence of a gene encoding catalase in T. cruzi has played an important role in allowing this parasite to develop a shrill capacity to sense and overcome oxidative stress.

  1. Eco-epidemiological aspects of Trypanosoma cruzi, Trypanosoma rangeli and their vector (Rhodnius pallescens in Panama Generalidades do Trypanosoma cruzi, do Trypanosoma rangeli e do seu vetor (Rhodnius pallescens no Panamá

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    Ana Maria de Vasquez

    2004-08-01

    Full Text Available The eco-epidemiology of T. cruzi infection was investigated in the Eastern border of the Panama Canal in Central Panama. Between 1999 and 2000, 1110 triatomines were collected: 1050 triatomines (94.6% from palm trees, 27 (2.4% from periurban habitats and 33 (3.0% inside houses. All specimens were identified as R. pallescens. There was no evidence of vector domiciliation. Salivary glands from 380 R. pallescens revealed a trypanosome natural infection rate of 7.6%, while rectal ampoule content from 373 triatomines was 45%. Isoenzyme profiles on isolated trypanosomes demonstrated that 85.4% (n = 88 were T. cruzi and 14.6% (n = 15 were T. rangeli. Blood meal analysis from 829 R. pallescens demonstrated a zoophilic vector behavior, with opossums as the preferential blood source. Seroprevalence in human samples from both study sites was less than 2%. Our results demonstrate that T. cruzi survives in the area in balanced association with R. pallescens, and with several different species of mammals in their natural niches. However, the area is an imminent risk of infection for its population, consequently it is important to implement a community educational program regarding disease knowledge and control measures.A epidemiologia da infecção do T. cruzi foi investigada na margem oriental do canal do Panamá, na região central da Republica do Panamá. A informação obtida durante o estudo avaliou fatores de risco da doença de Chagas nesta área. Entre 1999 e 2000, 1110 triatomíneos foram coletados: 1050 triatomíneos (94,6% em palmeiras, 27 (2,4% em habitats periurbanos e 33 (3,0% no interior de casas. Todos os espécimens foram identificados como R. pallescens. Não havia nenhuma evidência de domiciliação do vetor. O exame de glândulas salivares de 380 R. pallescens revelaram taxa de infecção natural por Trypanosoma de 7,6%, mas o conteúdo da ampola rectal de 373 triatomíneos mostrou 45% de positividade. Os perfis de isoenzimas em Trypanosomas isolados demonstraram que 85,4% (n = 88 eram T. cruzi e 14,6% (n = 15 eram T. rangeli. A análise da refeição de sangue de 829 R. pallescens demonstrou comportamento zoofílico do vetor, sendo os gambás a fonte preferencial de sangue. Soroprevalência nos seres humanos de ambos locais de estudo foi menos que 2%. Nossos resultados demonstram que T. cruzi sobrevive na área em associação equilibrada com R. pallescens e com diversas espécies diferentes de mamíferos em seus nichos naturais. Entretanto, a área é um risco eminente de infecção para sua população, pelo que é importante executar um programa educacional na comunidade a respeito das medidas, do conhecimento e do controle da doença.

  2. Ecologia de triatomíneos e transmissão do Trypanosoma cruzi, com especial referência ao Brasil

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    Mauro Pereira Barreto

    1976-12-01

    ecótopos naturais e artificiais. Embora tenham conseguido adaptar-se com maior ou menor sucesso à habitação humana e suas dependências, são encontradas também em diferentes ecótopos naturais. Além de participar do ciclo silvestre do T. cruzi têm importância no transporte do parasita para os ecótopos artificiais e na infestação inicial ou na reinfestação destes ecótopos livres de insetos pelo expurgo, constituindo também elos na cadeia de transmissão domiciUária da infecção. Exemplos: Panstrongylus megistus, Rhodnius prolixus, Rhodnius pallenscens, Triatoma sórdida, Triatoma brasiliensis, Triatoma maculata, Triatoma pseudomaculata, Triatoma quasayana etc. 5 Triatomíneos bem adotados aos ecótopos artificiais, mas, às vezes, ainda encontrados em focos residuais naturais. São os insetos mais importantes no ciclo domiciiiário do T.cruzi, mas podem, pelo menos em certas áreas, participar do ciclo silvestre da infecção. Exemplo: Triatoma infestans. 6 Triatomíneos estritamente domiciliados. Apesar disto, parecem ter menor importância no ciclo domiciiiário, especialmente na transmissão do T. cruzi ao homem, porque convivem mais com ratos comensais, embora também entrem em contacto com o homem. Exemplo: Triatoma rubrofasciata.On the basis of their ecological behavior the triatomines are distributed into six groups: 1. Typically wild insects, i. e., species that are found only in natural ecotopes, never being collected in human dweellings and their annexes. Consequently they never come into contact with man and domestic, commensal or synantropic mammals, unless they enter the natural foci. But these insects may have a more or less important role in maintaining the wild trypanosome enzooty. Examples: Psammolestes coreodes, Psammolestes tertius, Cavernicola pilosa, Triatoma dispar, Triatoma delpontei and other little known species. 2. Essentially wild insects whose adults occasionally invade human dwellings and their annexes but are unable to

  3. Índice de defecación y éxito reproductivo de Triatoma maculata (Hemiptera:Reduviidaeen condiciones de laboratorio

    Directory of Open Access Journals (Sweden)

    E Aldana

    2004-12-01

    Full Text Available Se estudió el comportamiento reproductivo y de defecación de Triatoma maculata (Erichson 1848alimentando artificialmente con sangre humana.Los estadios II y III mostraron mayor frecuencia de defecaciones (ID=0.6 n=40,el estadio V no alcanzó la diferenciación sexual, la fertilidad fue 55%(n=865,fecundidad 8 huevos/hembra/semana (n=26,22 días de desarrollo embrionario (n=477,longevidad de hembras 51 días (n=26,el tiempo intermuda aumenta progresivamente desde 35 días en el estadio I hasta 46 días en el estadio IV,el porcentaje de muda varió desde 0%en el estadio V hasta 63%en el estadio III,la mortalidad varió desde 8%en el estadio III hasta 100%en el estadio V (n=40.Los resultados del presente trabajo aportan evidencias que explican la menor capacidad vectorial y la baja densidad de T.maculata en el domicilio humano.Defecation index and reproductive success of Triatoma maculata (Hemiptera: Reduviidae under laboratory conditions.The reproductive and defecating behavior of Triatoma maculata (Erichson 1848was studied on animals from an university culture in Venezuela.This species does not reach the importance of Rhodnius prolixus Stal 1859 as Chagas disease vector in Venezuela.This study addressed the role of defecating frequency,an index of how dangerous the animals are for the human population,and its relationship with why T.maculata is a less important vector than R.prolixus .Human blood was fed to the insects through an artificial feeding device.The 2nd and 3rd instar nymphs defecated more frequently (Id=0.6,n=40,and our Vth instar nymphs did not complete sexual differentiation.Fertility was 55%(n=865and fecundity 8 eggs/female/week (n=26. Egg incubation lasted 22 days (n=477.Female longevity was 51 days (n=26.Intermould time grew progressively from 35 days for 1st to 40 days for 4th instar nymphs (n=40.Mould percentage varied from 0% for Vth to 63%for 3rd instar nymphs.Mortality varied from 8% for 3rd to 100% for Vth instar nymphs

  4. Comparative and functional triatomine genomics reveals reductions and expansions in insecticide resistance-related gene families.

    Science.gov (United States)

    Traverso, Lucila; Lavore, Andrés; Sierra, Ivana; Palacio, Victorio; Martinez-Barnetche, Jesús; Latorre-Estivalis, José Manuel; Mougabure-Cueto, Gaston; Francini, Flavio; Lorenzo, Marcelo G; Rodríguez, Mario Henry; Ons, Sheila; Rivera-Pomar, Rolando V

    2017-02-01

    Triatomine insects are vectors of Trypanosoma cruzi, a protozoan parasite that is the causative agent of Chagas' disease. This is a neglected disease affecting approximately 8 million people in Latin America. The existence of diverse pyrethroid resistant populations of at least two species demonstrates the potential of triatomines to develop high levels of insecticide resistance. Therefore, the incorporation of strategies for resistance management is a main concern for vector control programs. Three enzymatic superfamilies are thought to mediate xenobiotic detoxification and resistance: Glutathione Transferases (GSTs), Cytochromes P450 (CYPs) and Carboxyl/Cholinesterases (CCEs). Improving our knowledge of key triatomine detoxification enzymes will strengthen our understanding of insecticide resistance processes in vectors of Chagas' disease. The discovery and description of detoxification gene superfamilies in normalized transcriptomes of three triatomine species: Triatoma dimidiata, Triatoma infestans and Triatoma pallidipennis is presented. Furthermore, a comparative analysis of these superfamilies among the triatomine transcriptomes and the genome of Rhodnius prolixus, also a triatomine vector of Chagas' disease, and other well-studied insect genomes was performed. The expression pattern of detoxification genes in R. prolixus transcriptomes from key organs was analyzed. The comparisons reveal gene expansions in Sigma class GSTs, CYP3 in CYP superfamily and clade E in CCE superfamily. Moreover, several CYP families identified in these triatomines have not yet been described in other insects. Conversely, several groups of insecticide resistance related enzymes within each enzyme superfamily are reduced or lacking in triatomines. Furthermore, our qRT-PCR results showed an increase in the expression of a CYP4 gene in a T. infestans population resistant to pyrethroids. These results could point to an involvement of metabolic detoxification mechanisms on the high

  5. Comparative and functional triatomine genomics reveals reductions and expansions in insecticide resistance-related gene families.

    Directory of Open Access Journals (Sweden)

    Lucila Traverso

    2017-02-01

    Full Text Available Triatomine insects are vectors of Trypanosoma cruzi, a protozoan parasite that is the causative agent of Chagas' disease. This is a neglected disease affecting approximately 8 million people in Latin America. The existence of diverse pyrethroid resistant populations of at least two species demonstrates the potential of triatomines to develop high levels of insecticide resistance. Therefore, the incorporation of strategies for resistance management is a main concern for vector control programs. Three enzymatic superfamilies are thought to mediate xenobiotic detoxification and resistance: Glutathione Transferases (GSTs, Cytochromes P450 (CYPs and Carboxyl/Cholinesterases (CCEs. Improving our knowledge of key triatomine detoxification enzymes will strengthen our understanding of insecticide resistance processes in vectors of Chagas' disease.The discovery and description of detoxification gene superfamilies in normalized transcriptomes of three triatomine species: Triatoma dimidiata, Triatoma infestans and Triatoma pallidipennis is presented. Furthermore, a comparative analysis of these superfamilies among the triatomine transcriptomes and the genome of Rhodnius prolixus, also a triatomine vector of Chagas' disease, and other well-studied insect genomes was performed. The expression pattern of detoxification genes in R. prolixus transcriptomes from key organs was analyzed. The comparisons reveal gene expansions in Sigma class GSTs, CYP3 in CYP superfamily and clade E in CCE superfamily. Moreover, several CYP families identified in these triatomines have not yet been described in other insects. Conversely, several groups of insecticide resistance related enzymes within each enzyme superfamily are reduced or lacking in triatomines. Furthermore, our qRT-PCR results showed an increase in the expression of a CYP4 gene in a T. infestans population resistant to pyrethroids. These results could point to an involvement of metabolic detoxification mechanisms

  6. Effect of continuous and pulsed currents on microstructural evolution of stainless steel joined by TIG welding; Einfluss des Einsatzes von Dauerstrom und Impulsstrom auf die Mikrostrukturentwicklung bei durch das WIG-Schweissverfahren gefuegtem rostfreiem Stahl

    Energy Technology Data Exchange (ETDEWEB)

    Durgutlu, Ahmet; Findik, Tayfun; Guelenc, Behcet [Gazi Univ., Ankara (Turkey). Dept. of Metallurgy and Materials Engineering; Cevik, Bekir [Duezce Univ. (Turkey). Dept. of Welding Technology; Kaya, Yakup; Kahraman, Nizamettin [Karabuek Univ. (Turkey). Dept. of Manufacturing Engineering

    2015-07-01

    In this study, AISI 316L series austenitic stainless steel sheets were joined by tungsten inert gas welding method in continuous and pulsed currents. Regarding microstructural investigation and hardness values of weld metal, samples were welded to investigate the effect of current type on grain structures of weld metal. Results showed that samples welded by using pulsed current had considerable different properties compared to the samples welded by using continuous current. While the weld metals of joinings obtained by using continuous current displayed a coarse-grained and columnar structure, weld metals obtained by using pulsed current had a finer-grained structure. It was also found that hardness values of samples, which were welded with continuous and pulsed current, were quite different.

  7. Results of investigations regarding the physical and mechanical properties of the martensitic 9% Cr steel EUROFER '97; Ergebnisse von Charakterisierungsuntersuchungen zu physikalischen und mechanischen Eigenschaften des martensitischen 9% Cr-Stahles EUROFER '97

    Energy Technology Data Exchange (ETDEWEB)

    Schirra, M.; Falkenstein, A.; Graf, P.; Heger, S.; Kempe, H.; Lindau, R.; Zimmermann, H.

    2002-04-01

    Following the history of the development activities from conventional martensitic 12% Cr steel, MANET and OPTIFER up to low-activated EUROFER (RAFM steel), the results obtained from experiments on rods of 100 mm diameter and plates of 14 mm shall be presented for a basic characterization. The physical and mechanical properties shall be compared with those of OPTIFER-1W and the F82H-mod 2% W steel. To determine the conversion behavior, a continuous cct diagram was plotted. Hardening experiments in the temperature range of 850 - 1120 C illustrated the range of maximum hardness as well as grain size development. The notch impact behavior was described for various heat treatments and sample types at test temperatures ranging from +60 to -100 C. Tensile strengths were determined for various heat treatments at temperatures ranging from room temperature to 700 C. Aging due to a long-term heat treatment was investigated by means of stabilization annealing experiments. Creep rupture strength and creeping were investigated in the temperature range of 450 - 650 C. So far, a duration of up to about 15 000 h has been covered by the experiments. (orig.)

  8. Phase transformation and local mechanical properties of TRIP steel in a simulated and real resistance spot weld process; Phasenumwandlung und lokale mechanische Eigenschaften von TRIP Stahl beim simulierten und realen Widerstandspunktschweissprozess

    Energy Technology Data Exchange (ETDEWEB)

    Brauser, Stephan

    2013-06-01

    TRIP steels give high strength along with good ductility owing to metastable austenite to martensite phase transformation (TRIP effect) caused by mechanical load. Under the extreme process-specific heating and cooling rates of resistance spot welding, these materials may undergo modifications in their austenite portion resulting in changed mechano- technological performance locally. The prime objective of this study was therefore to carry out microstructure analyses of the spot weld area in order to identify the modified portion of austenite and the resulting changes in local mechanical performance with special consideration of the TRIP effect. First, the metastable austenite portion in the unprocessed parent metal was quantified by in-situ diffraction using high energy synchrotron radiation. Next, the basic aspects of temperature dependent austenite transformation in the heating and cooling process were investigated in furnace experiments under defined temperature profiles. Continuative Gleeble tests and furnace experiments were conducted using various temperature profiles with different peaks occurring locally in the spot welding process in order to enable systematic assessment of the influence of temperature and of heating and cooling conditions on the austenite content under real conditions. Correlation experiments between the mechanical characteristics of thermally prepared tensile specimens and the metallographically and roentgenographically determined austenite contents allowed it to ascertain the metastable, i.e. transformable austenite portions. Finally, the results were evaluated concerning their transferability to real resistance spot welds. It was demonstrated that the austenite to martensite phase transformation can come into action only in a strongly localized material area in the transition zone between heat-affected zone and base metal. Consequently, the TRIP effect does not significantly affect the strength and ductility performance in the joining area of spot welded TRIP steels. The established mechanical characteristics were used as input data for numerical simulation of the spot weld ductility and strength performance. Here, the attention was focused on the necessity of implementing mechanical characteristics of the heat-affected zone for realistic tensile shear test modelling. [German] TRIP Staehle realisieren durch eine unter mechanischer Beanspruchung hervorgerufene Phasenumwandlung von metastabilen Austenit in Martensit (TRIP-Effekt) hohe Festigkeiten bei gleichzeitig guten Verformungseigenschaften. Waehrend der Verarbeitung dieser Werkstoffe mittels Widerstandspunktschweissen koennen unter den prozessspezifischen extremen Aufheiz- und Abkuehlraten Modifikationen des Austenitanteils hervorgerufen werden die als Folge lokal zu einer Aenderung der mechanisch-technologischen Eigenschaften fuehren. Wesentliche Zielsetzung der vorliegenden Arbeit war daher die Analyse der Gefuegestruktur im Bereich einer Punktschweissverbindung hinsichtlich der Aenderung des Austenitanteils und den daraus resultierenden Aenderungen der lokalen mechanischen Eigenschaften unter besonderer Beruecksichtigung des TRIP-Effekts. Durch in-situ Beugungsuntersuchungen mittels hochenergetischer Synchrotronstrahlung erfolgte zunaechst die Quantifizierung des metastabilen Austenitanteils im unbehandelten Grundwerkstoff. Darauf aufbauend wurden unter definierten Temperaturprofilen in Ofenversuchen die grundlegenden Aspekte der thermisch bedingten Austenitumwandlung im Aufheiz- und Abkuehlprozess untersucht. Durch Gleeble-Versuche und Ofenexperimente wurden weiterfuehrend verschiedene Temperaturprofile mit unterschiedlichen im Punktschweissprozess lokal vorliegende Spitzentemperaturen genutzt um eine systematische Bewertung des Einflusses der Temperatur und der Aufheiz- sowie der Abkuehlbedingungen auf den Austenitgehalt unter realen Bedingungen zu ermoeglichen. Durch Korrelationsuntersuchungen zwischen den mechanischen Kennwerten thermisch praeparierter Zugproben und den mittels Metallographisch wie auch roentgenographisch ermittelten Austenitgehalten konnten die metastabilen, d.h. umwandlungsfaehigen Austenitanteile bestimmt werden. Schliesslich erfolgte eine Bewertung hinschlich der Uebertragbarkeit der Ergebnisse auf reale Widerstandspunktschweissverbindungen. Es wurde dabei der Nachweis erbracht, dass die Austenit-Martensit-Phasenumwandlung lediglich in einem lokal eng begrenzen Werkstoffbereich am Uebergang WEZ/Grundwerkstoff wirksam werden kann. Demzufolge fuehrt der TRIP-Effekt zu keiner signifikanten Beeinflussung von Festigkeits- und Verformungseigenschaften im Fuegebereich von widerstandspunktgeschweissten TRIP Staehlen. Die ermittelten mechanischen Kennwerte wurden abschliessend als Eingangsdaten fuer die numerische Simulation des Verformungs- und Festigkeitsverhaltens von Punkschweissverbindungen genutzt. Dabei wurde insbesondere die Notwendigkeit der Implementierung von mechanischen Kenndaten der Waermeeinflusszone fuer eine realitaetsnahe Modellierung von Scherzugversuchen untersucht.

  9. Fatigue of the quenched and hardened steel 42CrMo4 under multiaxial in- and out-of-phase loading; Ermuedung des Stahles 42CrMo4 unter mehrachsiger, phasenverschobener Beanspruchung

    Energy Technology Data Exchange (ETDEWEB)

    Loewisch, G. [Stiftung Inst. fuer Werkstofftechnik, Bremen (Germany); Bomas, H.; Mayr, P.

    1999-10-01

    Two kinds of specimens out of the quenched and hardened steel 42CrMo4 (similar SAE 4140) were tested by combined tension-torsion in- and out-of-phase loading. The specimens batches differed in the residual stress state. Under cyclic, stress controlled loading an elastic behaviour is registrated until 50% of the life time. Then a rapid softening occurs, which correlates with the von-Mises equivalent stress in the case of in-phase loading. At high stress amplitudes, the residual stresses may be neglected. The lifetime is best described by the fatigue criterion of Zenner which considers the integral average of the stress state in every plane. This stress state is described by a linear combination of the shear stress amplitude and the normal stress amplitude. Below the cyclic yield strength, the residual stresses must be taken into account as static stresses. The comparison of the local residual stress distributions is possible by using the weakest link model of Heckel, which is described in detail. (orig.)

  10. Ecological and economic assessment and optimisation of measures for in-house recycling in hot galvanizing plants; Oekologische und oekonomische Beurteilung und Optimierung von Massnahmen zur innerbetrieblichen Stoffkreislaufschliessung beim Feuerverzinken von Stahl

    Energy Technology Data Exchange (ETDEWEB)

    Ackermann, R.; Fleischer, G. [TU Berlin, Inst. fuer Technischen Umweltschutz, Lehrstuhl Abfallvermeidung und Sekundaerrohstoffwirtschaft, Berlin (Germany)

    2003-07-01

    Exemplary strategies for materials use and recycling in a plant for hot galvanizing of steel are reviewed from an ecological and economic viewpoint and optimized. The changes resulting from the optimization measures are assessed in terms of cost and potential ecological effects. The results of this assessment, which is based on the methodology published in DIN EN ISO 14040 ff, illustrate the potential contained in the recycling option. (orig.) [German] Fuer das Feuerverzinken von Stahlbauteilen werden beispielhaft Strategien zur innerbetrieblichen Stoffkreislaufschliessung oekologisch und oekonomisch beurteilt und optimiert. Die sich hinsichtlich der betrieblichen Stoff- und Energiefluesse durch Optimierungsmassnahmen ergebenden Veraenderungen werden in Bezug auf die Kostensituation des Unternehmens und die oekologischen potentiellen Auswirkungen beurteilt. Die Ergebnisse der Oekologischen Betriebsoptimierung, die unter Nutzung methodischer Elemente der Oekobilanzierung (DIN EN ISO 14040 ff) erzielt werden, verdeutlichen, welche Potentiale in einer weitgehenden Schliessung des Stoffkreislaufs liegen. (orig.)

  11. Automated segmentation of synchrotron radiation micro-computed tomography biomedical images using Graph Cuts and neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Alvarenga de Moura Meneses, Anderson, E-mail: ameneses@ieee.org [Radiological Sciences Laboratory, Rio de Janeiro State University, Rua Sao Francisco Xavier 524, CEP 20550-900, RJ (Brazil); Giusti, Alessandro [IDSIA (Dalle Molle Institute for Artificial Intelligence), University of Lugano (Switzerland); Pereira de Almeida, Andre; Parreira Nogueira, Liebert; Braz, Delson [Nuclear Engineering Program, Federal University of Rio de Janeiro, RJ (Brazil); Cely Barroso, Regina [Laboratory of Applied Physics on Biomedical Sciences, Physics Department, Rio de Janeiro State University, RJ (Brazil); Almeida, Carlos Eduardo de [Radiological Sciences Laboratory, Rio de Janeiro State University, Rua Sao Francisco Xavier 524, CEP 20550-900, RJ (Brazil)

    2011-12-21

    Synchrotron Radiation (SR) X-ray micro-Computed Tomography ({mu}CT) enables magnified images to be used as a non-invasive and non-destructive technique with a high space resolution for the qualitative and quantitative analyses of biomedical samples. The research on applications of segmentation algorithms to SR-{mu}CT is an open problem, due to the interesting and well-known characteristics of SR images for visualization, such as the high resolution and the phase contrast effect. In this article, we describe and assess the application of the Energy Minimization via Graph Cuts (EMvGC) algorithm for the segmentation of SR-{mu}CT biomedical images acquired at the Synchrotron Radiation for MEdical Physics (SYRMEP) beam line at the Elettra Laboratory (Trieste, Italy). We also propose a method using EMvGC with Artificial Neural Networks (EMANNs) for correcting misclassifications due to intensity variation of phase contrast, which are important effects and sometimes indispensable in certain biomedical applications, although they impair the segmentation provided by conventional techniques. Results demonstrate considerable success in the segmentation of SR-{mu}CT biomedical images, with average Dice Similarity Coefficient 99.88% for bony tissue in Wistar Rats rib samples (EMvGC), as well as 98.95% and 98.02% for scans of Rhodnius prolixus insect samples (Chagas's disease vector) with EMANNs, in relation to manual segmentation. The techniques EMvGC and EMANNs cope with the task of performing segmentation in images with the intensity variation due to phase contrast effects, presenting a superior performance in comparison to conventional segmentation techniques based on thresholding and linear/nonlinear image filtering, which is also discussed in the present article.

  12. NMR studies of the dynamics of high-spin nitrophorins: comparative studies of NP4 and NP2 at close to physiological pH.

    Science.gov (United States)

    Berry, Robert E; Muthu, Dhanasekaran; Yang, Fei; Walker, F Ann

    2015-01-20

    The β-barrel nitrophorin (NP) heme proteins are found in the saliva of the blood-sucking insect Rhodnius prolixus, which synthesizes and stores nitric oxide (NO) in the salivary glands. NO is bound to iron of the NPs and is released by dilution and an increase in pH when the insect spits its saliva into the tissues of a victim, to aid in obtaining a blood meal. In the adult insect, there are four nitrophorins, NP1-NP4, which have sequence similarities in two pairs, NP1 and NP4 (90% identical) and NP2 and NP3 (80% identical). The available crystal structures of NP4 have been used to propose that pH-dependent changes in the conformation of two loops between adjacent β-strands at the front opening of the protein, the A-B and G-H loops, determine the rate of NO release. At pH 7.3, NP4 releases NO 17 times faster than NP2 does. In this work, the aqua complexes of NP4 and NP2 have been investigated by nuclear magnetic resonance (NMR) relaxation measurements to probe the pico- to nanosecond and micro- to millisecond time scale motions at two pH values, 6.5 and 7.3. It is found that NP4-OH2 is fairly rigid and only residues in the loop regions show dynamics at pH 6.5; at pH 7.3, much more dynamics of the loops and most of the β-strands are observed while the α-helices remain fairly rigid. In comparison, NP2-OH2 shows much less dynamics, albeit somewhat more than that of the previously reported NP2-NO complex [Muthu, D., Berry, R. E., Zhang, H., and Walker, F. A. (2013) Biochemistry 52, 7910-7925]. The reasons for this major difference between NP4 and NP2 are discussed.

  13. Cathepsin L of Triatoma brasiliensis (Reduviidae, Triatominae): sequence characterization, expression pattern and zymography.

    Science.gov (United States)

    Waniek, Peter J; Pacheco Costa, Juliana E; Jansen, Ana M; Costa, Jane; Araújo, Catarina A C

    2012-01-01

    Triatoma brasiliensis is considered one of the main vectors of Chagas disease commonly found in semi-arid areas of northeastern Brazil. These insects use proteases, such as carboxypeptidase B, aminopeptidases and different cathepsins for blood digestion. In the present study, two genes encoding cathepsin L from the midgut of T. brasiliensis were identified and characterized. Mature T. brasiliensis cathepsin L-like proteinases (TBCATL-1, TBCATL-2) showed a high level of identity to the cathepsin L-like proteinases of other insects, with highest similarity to Rhodnius prolixus. Both cathepsin L transcripts were highly abundant in the posterior midgut region, the main region of the blood digestion. Determination of the pH in the whole intestine of unfed T. brasiliensis revealed alkaline conditions in the anterior midgut region (stomach) and acidic conditions in the posterior midgut region (small intestine). Gelatine in-gel zymography showed the activity of at least four distinct proteinases in the small intestine and the cysteine proteinase inhibitors transepoxysuccinyl-l-leucylamido-(4-guanidino)butane (E-64) and cathepsin B inhibitor and N-(l-3-trans-propylcarbamoyl-oxirane-2-carbonyl)-l-isoleucyl-l-proline (CA-074) were employed to characterize enzymatic activity. E-64 fully inhibited cysteine proteinase activity, whereas in the samples treated with CA-074 residual proteinase activity was detectable. Thus, proteolytic activity could at least partially be ascribed to cathepsin L. Western blot analysis using specific anti cathepsin L antibodies confirmed the presence of cathepsin L in the lumen of the small intestine of the insects. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Estudo sobre a epidemiologia da doença de Chagas no Ceará. V. Quirópteros infectados com Tripanosomo tipo cruzi

    Directory of Open Access Journals (Sweden)

    J.E. de Alencar

    1976-12-01

    Full Text Available Numa série de pesquisas sobre a epidemiologia da Doença de Chagas no Ceará, muitas espécies de mamíferos foram examinadas, dentre elas algumas espécies de quirópteros. Já antes, no Brasil, 15 espécies foram encontradas infectadas com tripanosomo tipo cruzi, dentre as 30 encontradas infectadas na América, de 1931 a 1964. Esses estudos se fizeram aproveitando o material do Censo Relativo de Morcegos na área da Serra de Maranguape (realizado por dois autores, abrangendo os municípios de Maranguape e Caucaia. Em 141 exemplares (18 espécies e 5 famílias foram feitos xenos com 5 ninfas de Rhodnius prolixus. Examinando o material 30 a 45 dias depois, foram encontrados infectados 9 exemplares, todos da família Phyllostomidae: 7 Artibeus jamaicensis, 1 Glossophaga soricina e 1 Trachops cirrhosus. O primeiro já havia sido encontrado infectado na Colombia e no Panamá; o segundo o foi na Colombia e no Brasil (Estado do Pará; o terceiro o é pela primeira vez. As duas primeiras espécies são insetívoras e frugívoras; a terceira é carnívora, além de frugívora e insetívora. Os parasitos isolados apresentaram características morfológicas e de cultura que permitem colocá-los no grupo dos tripanosomos tipo cruzi.' infectaram triatomíneos e produziram parasitemia (baixa e lesões típicas em camundongos brancos. A cepa de T. cirrhosus não foi isolada, mas as formas metacíclicas em triatomíneos eram semelhantes.

  15. Characterization of burdock mottle virus, a novel member of the genus Benyvirus, and the identification of benyvirus-related sequences in the plant and insect genomes.

    Science.gov (United States)

    Kondo, Hideki; Hirano, Shuichi; Chiba, Sotaro; Andika, Ida Bagus; Hirai, Makoto; Maeda, Takanori; Tamada, Tetsuo

    2013-10-01

    The complete nucleotide sequence of the burdock mottle virus (BdMoV) isolated from an edible burdock plant (Arctium lappa) in Japan has been determined. BdMoV has a bipartite genome, whose organization is similar to RNA1 and RNA2 of benyviruses, beet necrotic yellow vein virus (BNYVV), beet soil-borne mosaic virus (BSBMV), and rice stripe necrosis virus (RSNV). BdMoV RNA1 (7038 nt) contains a single open reading frame (ORF) encoding a 249-kDa polypeptide that consists of methyl-transferase, helicase, papain-like protease, AlkB-like, and RNA-dependent RNA polymerase domains. The AlkB-like domain sequence is not present in the proteins encoded by other known benyviruses, but is found in replication-associated proteins of viruses mainly belonging to the families Alfaflexiviridae and Betaflexiviridae. BdMoV RNA2 (4315 nt) contains six ORFs that are similar to those of benyviruses: these are coat protein (CP), CP readthrough, triple gene block movement and cysteine-rich proteins. Phylogenetic analyses showed that BdMoV is more closely related to BNYVV and BSBMV than to RSNV. Database searches showed that benyvirus replicase-related sequences are present in the chromosomes of a chickpea plant (Cicer arietinum) and a blood-sucking insect (Rhodnius prolixus). Some other benyvirus-related sequences are found in the transcriptome shotgun libraries of a few species of plants and a bark beetle. Our results show that BdMoV is a distinct species of the genus Benyvirus and that ancestral and extant benyviruses may have infected or currently infect a wide range of hosts, including plants and insects. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. [Possible oral transmission of Chagas disease among hydrocarbons sector workers in Casanare, Colombia, 2014].

    Science.gov (United States)

    Zuleta-Dueñas, Liliana Patricia; López-Quiroga, Ángela Johana; Torres-Torres, Fernando; Castañeda-Porras, Oneida

    2017-06-01

    Trypanosoma cruzi, the etiological agent for Chagas disease, can be transmitted by oral intake of contaminated food or drinks. During epidemiological week 14 of 2014, two cases of acute Chagas disease were notified among hydrocarbons sector workers in Paz de Ariporo, Casanare. To characterize the affected population, to establish control and prevention measures and to confirm the outbreak. We conducted an outbreak investigation that included the following components: a) Search for symptomatic people compatible with Chagas disease according to the case definition for their referral to medical services; b) entomological survey (192/197 houses); c) sanitary inspection and microbiological analysis of food samples; and d) study of reservoirs. Data management and analysis were done with Epi-Info 7.1.5 using descriptive statistics. We also calculated intradomicile and peridomicile triatomine infestation indexes. We detected 552 exposed people; 40 had the disease (7.2%), of whom seven were women (17,5%) and 33, men (82.5%), i.e., a male-female ratio of 5:1. The mean age was 39.1 ± 10.8 years; the attack rate was 7.2% and lethality, 5% (2/40). Symptoms included fever (100% of cases), headache (80%), myalgia and arthralgia (65%), facial edema (55%), and abdominal pain (37.5%). The mean incubation time was 17 days (range: 3-21). Rhodnius prolixus domiciliary infestation index was 3.3 % and 2.2% in the peridomicile. In the five restaurants inspected sanitary conditions were deficient and food samples were microbiologically non-conforming. We found a dog and two opossums positive for IgG antibodies by ELISA. Environmental, sanitary and epidemiological conditions at the place confirmed an outbreak of Chagas diseases related to occupational exposure, possibly by oral transmission, which may be the largest to date in Colombia.

  17. Automated segmentation of synchrotron radiation micro-computed tomography biomedical images using Graph Cuts and neural networks

    International Nuclear Information System (INIS)

    Alvarenga de Moura Meneses, Anderson; Giusti, Alessandro; Pereira de Almeida, André; Parreira Nogueira, Liebert; Braz, Delson; Cely Barroso, Regina; Almeida, Carlos Eduardo de

    2011-01-01

    Synchrotron Radiation (SR) X-ray micro-Computed Tomography (μCT) enables magnified images to be used as a non-invasive and non-destructive technique with a high space resolution for the qualitative and quantitative analyses of biomedical samples. The research on applications of segmentation algorithms to SR-μCT is an open problem, due to the interesting and well-known characteristics of SR images for visualization, such as the high resolution and the phase contrast effect. In this article, we describe and assess the application of the Energy Minimization via Graph Cuts (EMvGC) algorithm for the segmentation of SR-μCT biomedical images acquired at the Synchrotron Radiation for MEdical Physics (SYRMEP) beam line at the Elettra Laboratory (Trieste, Italy). We also propose a method using EMvGC with Artificial Neural Networks (EMANNs) for correcting misclassifications due to intensity variation of phase contrast, which are important effects and sometimes indispensable in certain biomedical applications, although they impair the segmentation provided by conventional techniques. Results demonstrate considerable success in the segmentation of SR-μCT biomedical images, with average Dice Similarity Coefficient 99.88% for bony tissue in Wistar Rats rib samples (EMvGC), as well as 98.95% and 98.02% for scans of Rhodnius prolixus insect samples (Chagas's disease vector) with EMANNs, in relation to manual segmentation. The techniques EMvGC and EMANNs cope with the task of performing segmentation in images with the intensity variation due to phase contrast effects, presenting a superior performance in comparison to conventional segmentation techniques based on thresholding and linear/nonlinear image filtering, which is also discussed in the present article.

  18. Infestación por triatominos en comunidades indígenas de Valledupar, Colombia Infestação por barbeiros em comunidades indígenas de Valledupar, Colômbia Infestation by triatomine bugs in indigenous communities of Valledupar, Colombia

    Directory of Open Access Journals (Sweden)

    Marleny Montilla

    2011-08-01

    Full Text Available OBJETIVO: Calcular los índices infestación por triatominos en comunidades indígenas en Colombia. MÉTODOS: Se realizó estudio descriptivo en 19 comunidades indígenas del municipio de Valledupar Departamento de Cesar, Colombia. Durante junio a diciembre de 2007 se recolectaron triatominos por búsqueda activa en las viviendas de los indígenas. Los insectos luego fueron identificados por las claves de Lent & Wygodzinsky. Se desarrolló estudio del proceso infectivo en modelo animal y análisis enzimático de cepas de Trypanosoma cruzi, detectadas en heces de triatominos. RESULTADOS: Rhodnius prolixus presentó índice de densidad en las viviendas de 154,7%, Triatoma dimidiata de 102,45%, Triatoma maculata de 109,25% y Panstrogylus geniculatus de 0,3%. El índice promedio de infestación de las cuatro especies fue de 40,54% y, el de infección con T. cruzi de 9,4%. De cinco hemocultivos positivos para T. cruzi, tres se caracterizaron por isoenzimas, clasificándose en T. cruzi grupo I. El estudio de las biopsias reveló pocas características patológicas durante el proceso de infección con las cepas de T. cruzi aisladas de triatominos domiciliados. CONCLUSIÓN: Los altos índices de infestación por triatominos en las viviendas y el índice de infección por T. cruzi, evidencian la transmisión activa de la enfermedad de Chagas, situación que amerita la aplicación de medidas de control vectorial y el estudio seroepidemilógico de la población en riesgo. La identificación de las cepas de T. cruzi como grupo I concuerda con otros estudios realizados en esta región colombiana.OBJETIVO: Calcular índices de infestação por barbeiros em comunidades indígenas da Colômbia. MÉTODOS: Estudo descritivo em 19 comunidades do município de Valledupar, departamento de Cesar, Colômbia. A coleta de barbeiros foi realizada por busca ativa nas casas dos indígenas de junho e dezembro de 2007. A identificação taxonômica foi feita conforme Lent

  19. Truly costly sequential search and oligopolistic pricing

    NARCIS (Netherlands)

    Janssen, Maarten C W; Moraga-González, José Luis; Wildenbeest, Matthijs R.

    We modify the paper of Stahl (1989) [Stahl, D.O., 1989. Oligopolistic pricing with sequential consumer search. American Economic Review 79, 700-12] by relaxing the assumption that consumers obtain the first price quotation for free. When all price quotations are costly to obtain, the unique

  20. Dimerization of nitrophorin 4 at low pH and comparison to the K1A mutant of nitrophorin 1.

    Science.gov (United States)

    Berry, Robert E; Yang, Fei; Shokhireva, Tatiana K; Amoia, Angela M; Garrett, Sarah A; Goren, Allena M; Korte, Stephanie R; Zhang, Hongjun; Weichsel, Andrzej; Montfort, William R; Walker, F Ann

    2015-01-20

    Nitrophorin 4, one of the four NO-carrying heme proteins from the salivary glands of Rhodnius prolixus, forms a homodimer at pH 5.0 with a Kd of ∼8 μM. This dimer begins to dissociate at pH 5.5 and is completely dissociated to monomer at pH 7.3, even at 3.7 mM. The dimer is significantly stabilized by binding NO to the heme and at pH 7.3 would require dilution to well below 0.2 mM to completely dissociate the NP4-NO homodimer. The primary techniques used for investigating the homodimer and the monomer-dimer equilibrium were size-exclusion fast protein liquid chromatography at pH 5.0 and (1)H{(15)N} heteronuclear single-quantum coherence spectroscopy as a function of pH and concentration. Preparation of site-directed mutants of NP4 (A1K, D30A, D30N, V36A/D129A/L130A, K38A, R39A, K125A, K125E, D132A, L133V, and K38Q/R39Q/K125Q) showed that the N-terminus, D30, D129, D132, at least one heme propionate, and, by association, likely also E32 and D35 are involved in the dimerization. The "closed loop" form of the A-B and G-H flexible loops of monomeric NP4, which predominates in crystal structures of the monomeric protein reported at pH 5.6 but not at pH 7.5 and which involves all of the residues listed above except D132, is required for dimer formation. Wild-type NP1 does not form a homodimer, but NP1(K1A) and native N-terminal NP1 form dimers in the presence of NO. The homodimer of NP1, however, is considerably less stable than that of NP4 in the absence of NO. This suggests that additional aspartate or glutamate residues present in the C-terminal region of NP4, but not NP1, are also involved in stabilizing the dimer.

  1. Hallazgo de Trypanosoma Cruzi en momias de más de 4000 años de antigüedad

    Directory of Open Access Journals (Sweden)

    Carlos Jaramillo

    2000-08-01

    Full Text Available

    Se presentan los antecedentes de la presencia de triatominos domiciliados en Colombia desde la primera publicación hecha por el doctor César Uribe en 1929 (Editorial Minerva, Bogotá donde se consigna el hallazgo de Trypanosoma cruzi y Trypanosoma rangeli en 15 ejemplares de Rhodnius prolixus provenientes de Prado, Tolima. A continuación se analizan las demás publicaciones en orden cronológico. Informe del Profesor Emile Brumpt (Revista de Higiene, año XX – Números 11 y 12, 1939, Distribución de los Triatominos en Colombia, Hernando Ucrós, Hernando Rocha, Marcos Duque (Antioquia Médica Vol. 21 – 1971 No. 8; Distribution of Triatomine – transmitted trypanosomamiasis in Colombia and vew records of the bugs and infections. A. D’Alessandro, Pablo Barreto and C. A. Duarte R. (1972, J. Med. Ent. Vol. 8, No. 2: 159-172; Colombian Triatominae and their infestation with Trypanosomatid Flagellates. Marinkelle Cornelis J. (1972 Mitt Inst. – Aleman Invest. Cient. 6:13-29; Nuevos registros de triatominos domiciliarios y extradomiciliarios en Colombia. Antonio D’Alessandro, Pablo Barreto y Mauricio Thomas. Colombia Médica Vol. 12 No. 2 – 1981.

    Basándose en la anterior información se llega a la conclusión de que los Triatominae domiciliados en Colombia se encuentran en poblaciones situadas sobre los 2.000msnm, principalmente en las zonas central y oriental del país.

    El Instituto Nacional de Salud en el año de 1990, como una primera etapa para tratar de determinar la magnitud del problema de la tripanosomiasis americana en Colombia, realizó una investigación para establecer la verdadera distribución de los triatominos domiciliarios en el país.

    El estudio se hizo usando el sistema de muestreo, en una muestra estadísticamente representativa. Se inspeccionaron las viviendas de las zonas rurales; se capturaron triatominos vectores que, posteriormente, fueron examinados sistemáticamente en búsqueda de

  2. Distribución de Triatomíneos domiciliados en Colombia.

    Directory of Open Access Journals (Sweden)

    Augusto Corredor Arjona

    2000-08-01

    Full Text Available

    Se presentan los antecedentes de la presencia de triatominos domiciliados en Colombia desde la primera publicación hecha por el doctor César Uribe en 1929 (Editorial Minerva, Bogotá donde se consigna el hallazgo de Trypanosoma cruzi y Trypanosoma rangeli en 15 ejemplares de Rhodnius prolixus provenientes de Prado, Tolima. A continuación se analizan las demás publicaciones en orden cronológico. Informe del Profesor Emile Brumpt (Revista de Higiene, año XX – Números 11 y 12, 1939, Distribución de los Triatominos en Colombia, Hernando Ucrós, Hernando Rocha, Marcos Duque (Antioquia Médica Vol. 21 – 1971 No. 8; Distribution of Triatomine – transmitted trypanosomamiasis in Colombia and vew records of the bugs and infections. A. D’Alessandro, Pablo Barreto and C. A. Duarte R. (1972, J. Med. Ent. Vol. 8, No. 2: 159-172; Colombian Triatominae and their infestation with Trypanosomatid Flagellates. Marinkelle Cornelis J. (1972 Mitt Inst. – Aleman Invest. Cient. 6:13-29; Nuevos registros de triatominos domiciliarios y extradomiciliarios en Colombia. Antonio D’Alessandro, Pablo Barreto y Mauricio Thomas. Colombia Médica Vol. 12 No. 2 – 1981.

    Basándose en la anterior información se llega a la conclusión de que los Triatominae domiciliados en Colombia se encuentran en poblaciones situadas sobre los 2.000msnm, principalmente en las zonas central y oriental del país.

    El Instituto Nacional de Salud en el año de 1990, como una primera etapa para tratar de determinar la magnitud del problema de la tripanosomiasis americana en Colombia, realizó una investigación para establecer la verdadera distribución de los triatominos domiciliarios en el país.

    El estudio se hizo usando el sistema de muestreo, en una muestra estadísticamente representativa. Se inspeccionaron las viviendas de las zonas rurales; se capturaron triatominos vectores que, posteriormente, fueron examinados sistemáticamente en búsqueda de

  3. Comparación de métodos para la captura de triatominos (Hemiptera: Reduviidae en palmas Attalea butyracea en los Llanos Orientales de Colombia

    Directory of Open Access Journals (Sweden)

    Víctor Manuel Angulo

    2013-12-01

    Full Text Available Introducción. El estudio de los triatominos en sus ecótopos naturales tiene gran significado en la epidemiología de la enfermedad de Chagas. La recolección de insectos vivos y su establecimiento en insectarios permite realizar incontables estudios. Por ello se necesitan métodos efectivos para la captura de triatominos silvestres, especialmente especies intrusas como Rhodnius prolixus. Objetivo. Comparar cuatro métodos para la captura de triatominos en palmas para medir su efectividad. Materiales y métodos. El estudio se llevó a cabo en la localidad de Maní, departamento de Casanare, Colombia, con predominio de Attalea butyracea. Se compararon cuatro metodologías en 67 palmas: trampas con cebo vivo, búsqueda directa en palmas, tala y disección. Resultados. Los métodos fueron efectivos para recolectar ejemplares juveniles y adultos. La tala y la búsqueda manual mostraron los mayores índices de infestación (100 % y 83,33 %. La trampa Angulo mostró mayores índices de hacinamiento (4,93, densidad (3,76, rango de abundancia (1-13 e índice adulto/ninfa (0,22. La tala y la disección fue el método que significativamente recolectó más triatominos en comparación con los otros (p0,05. Conclusiones. Aunque la tala fue el mejor método para la recolección del mayor número de triatominos, los métodos con el cebo vivo con adhesivos o refugios para atrapar los insectos, fueron una buena alternativa. Entre ellos, la trampa Angulo mostró mejores resultados y evitó la exposición del investigador al riesgo y la intervención de ecotopos naturales.   doi: http://dx.doi.org/10.7705/biomedica.v33i4.835

  4. Decoding the anti-Trypanosoma cruzi action of HIV peptidase inhibitors using epimastigotes as a model.

    Directory of Open Access Journals (Sweden)

    Leandro S Sangenito

    Full Text Available BACKGROUND: Aspartic peptidase inhibitors have shown antimicrobial action against distinct microorganisms. Due to an increase in the occurrence of Chagas' disease/AIDS co-infection, we decided to explore the effects of HIV aspartic peptidase inhibitors (HIV-PIs on Trypanosoma cruzi, the etiologic agent of Chagas' disease. METHODOLOGY AND PRINCIPAL FINDINGS: HIV-PIs presented an anti-proliferative action on epimastigotes of T. cruzi clone Dm28c, with IC50 values ranging from 0.6 to 14 µM. The most effective inhibitors, ritonavir, lopinavir and nelfinavir, also had an anti-proliferative effect against different phylogenetic T. cruzi strains. The HIV-PIs induced some morphological alterations in clone Dm28c epimastigotes, as reduced cell size and swollen of the cellular body. Transmission electron microscopy revealed that the flagellar membrane, mitochondrion and reservosomes are the main targets of HIV-PIs in T. cruzi epimastigotes. Curiously, an increase in the epimastigote-into-trypomastigote differentiation process of clone Dm28c was observed, with many of these parasites presenting morphological alterations including the detachment of flagellum from the cell body. The pre-treatment with the most effective HIV-PIs drastically reduced the interaction process between epimastigotes and the invertebrate vector Rhodnius prolixus. It was also noted that HIV-PIs induced an increase in the expression of gp63-like and calpain-related molecules, and decreased the cruzipain expression in epimastigotes as judged by flow cytometry and immunoblotting assays. The hydrolysis of a cathepsin D fluorogenic substrate was inhibited by all HIV-PIs in a dose-dependent manner, showing that the aspartic peptidase could be a possible target to these drugs. Additionally, we verified that ritonavir, lopinavir and nelfinavir reduced drastically the viability of clone Dm28c trypomastigotes, causing many morphological damages. CONCLUSIONS AND SIGNIFICANCE: The results

  5. Disintegrins from Hematophagous Sources

    Directory of Open Access Journals (Sweden)

    Ivo M. B. Francischetti

    2012-04-01

    Full Text Available Bloodsucking arthropods are a rich source of salivary molecules (sialogenins which inhibit platelet aggregation, neutrophil function and angiogenesis. Here we review the literature on salivary disintegrins and their targets. Disintegrins were first discovered in snake venoms, and were instrumental in our understanding of integrin function and also for the development of anti-thrombotic drugs. In hematophagous animals, most disintegrins described so far have been discovered in the salivary gland of ticks and leeches. A limited number have also been found in hookworms and horseflies, and none identified in mosquitoes or sand flies. The vast majority of salivary disintegrins reported display a RGD motif and were described as platelet aggregation inhibitors, and few others as negative modulator of neutrophil or endothelial cell functions. This notably low number of reported disintegrins is certainly an underestimation of the actual complexity of this family of proteins in hematophagous secretions. Therefore an algorithm was created in order to identify the tripeptide motifs RGD, KGD, VGD, MLD, KTS, RTS, WGD, or RED (flanked by cysteines in sialogenins deposited in GenBank database. The search included sequences from various blood-sucking animals such as ticks (e.g., Ixodes sp., Argas sp., Rhipicephalus sp., Amblyomma sp., tabanids (e.g., Tabanus sp., bugs (e.g., Triatoma sp., Rhodnius prolixus, mosquitoes (e.g., Anopheles sp., Aedes sp., Culex sp., sand flies (e.g., Lutzomyia sp., Phlebotomus sp., leeches (e.g., Macrobdella sp., Placobdella sp. and worms (e.g., Ancylostoma sp.. This approach allowed the identification of a remarkably high number of novel putative sialogenins with tripeptide motifs typical of disintegrins (>450 sequences whose biological activity remains to be verified. This database is accessible

  6. Infestación por triatominos en comunidades indígenas de Valledupar, Colombia

    Directory of Open Access Journals (Sweden)

    Marleny Montilla

    2011-08-01

    Full Text Available OBJETIVO: Calcular los índices infestación por triatominos en comunidades indígenas en Colombia. MÉTODOS: Se realizó estudio descriptivo en 19 comunidades indígenas del municipio de Valledupar Departamento de Cesar, Colombia. Durante junio a diciembre de 2007 se recolectaron triatominos por búsqueda activa en las viviendas de los indígenas. Los insectos luego fueron identificados por las claves de Lent & Wygodzinsky. Se desarrolló estudio del proceso infectivo en modelo animal y análisis enzimático de cepas de Trypanosoma cruzi, detectadas en heces de triatominos. RESULTADOS: Rhodnius prolixus presentó índice de densidad en las viviendas de 154,7%, Triatoma dimidiata de 102,45%, Triatoma maculata de 109,25% y Panstrogylus geniculatus de 0,3%. El índice promedio de infestación de las cuatro especies fue de 40,54% y, el de infección con T. cruzi de 9,4%. De cinco hemocultivos positivos para T. cruzi, tres se caracterizaron por isoenzimas, clasificándose en T. cruzi grupo I. El estudio de las biopsias reveló pocas características patológicas durante el proceso de infección con las cepas de T. cruzi aisladas de triatominos domiciliados. CONCLUSIÓN: Los altos índices de infestación por triatominos en las viviendas y el índice de infección por T. cruzi, evidencian la transmisión activa de la enfermedad de Chagas, situación que amerita la aplicación de medidas de control vectorial y el estudio seroepidemilógico de la población en riesgo. La identificación de las cepas de T. cruzi como grupo I concuerda con otros estudios realizados en esta región colombiana.

  7. Prevalencia de patologías tropicales y factores de riesgo en la comunidad indígena de bunkwimake, sierra nevada de Santa Marta

    Directory of Open Access Journals (Sweden)

    Juan C. Dib

    2013-10-01

    Full Text Available Las enfermedades tropicales son endémicas en la Sierra Nevada de Santa Marta, sin embargo se carece de información acerca de la distribución de estas enfermedades en las comunidades indígenas que la habitan. Mediante estudios entomológicos y seroepidemiológicos, se estudiaron los factores de riesgo y la prevalencia de enfermedad de Chagas, leishmaniosis, hepatitis B y parasitosis intestinales en la comunidad indígena de Bunkwimake, ubicada en la vertiente norte de la Sierra Nevada. Los resultados de los estudios serológicos en 94 individuos reportaron una positividad de 18 (19%, 52(55% y 19(20% para infección por Tripanosoma cruzi, leishmania y el virus de la hepatitis B respectivamente. Adicionalmente, en 41(74% de 56 niños indígenas se encontró la presencia de parasitosis intestinales al examen coprológico. En los estudios entomológicos se captu-raron 37 triatominos en 16 viviendas distribuidos de la siguiente manera: 13 Triatoma dimidiata, 12 Rhodnius prolixus y 12 Pastrongylus geniculatus. Las tres especies se encontraron colonizando las viviendas indígenas y presentaron infeccilón para Trypanosoma cruzi. Dos especies de flebotominos fueron capturados en las vivien-das: 5 lutzomyia Gomezi y 7 Lutzomyia hirsute hirsute. El presente estudio demostró una importante prevalencia de infección por T. Cruzi y Leishmania en la población infantil, indicando transmisión reciente de ambas infec-ciones. Adicionalmente, los estudios entomológicos indican que existe un riesgo de transmisión doméstica de T. Cruzi y Leishmania por especies selváticas de triatominos y flebotominos. Se necesitan estudios adicionales que determinen la ecoepidemiología y dinámicas de trasnmisión de la Leishmanisosis y la enfermedad de Chagas en esta población para diseñar estrategias de control más adecuadas. Debido a que los programas verticales de fumigación y mejoramiento de vivienda en las comunidades indígenas no son viables, nuevas

  8. Ecological and biogeographical observations on Cerambycidae (Coleoptera) from California, USA

    OpenAIRE

    Swift, Ian

    2009-01-01

    New ecological and biogeographical observations are presented for the following 32 species of Cerambycidae from California: Atimia confusa dorsalis LeConte, Anelaphus albofasciatus (Linell), Aneflus prolixus prolixus LeConte, Anoplocurius incompletus Linsley, Brothylus conspersus LeConte, Callidiellum virescens Chemsak and Linsley, Calloides lorquini (Buquet), Clytus chemsaki Hovore and Giesbert, Enaphalodes hispicornis (Linnaeus), Methia brevis Fall, Neaneflus fuchsi (Wickham), Neoclytus bal...

  9. Estimation of the dangers of corrosion of steel containers and pipes used for storage and transport of hydrogen and hydrogen-containing gases under high pressure. Abschaetzung der Korrosionsgefaehrdung von Behaeltern und Rohrleitungen aus Stahl fuer Speicherung und Transport von Wasserstoff und wasserstoffhaltigen Gasen unter hohen Druecken

    Energy Technology Data Exchange (ETDEWEB)

    Poepperling, R; Schwenk, W; Venkateswarlu, J

    1982-01-01

    In the field of energy transportation, questions are increasingly being asked about possible corrosion damage through cold pressurized water. This concerns both pure hydrogen and hydrogen-containing gas mixtures, e.g. synthesis gas. For the estimation of probability of corrosion, data extracted from the literature concerning known cases of damage and the degree of influence on corrosion classed according to gas, material and operational parameters was evaluated. Damage from hydrogen can occur with dry and moist gases. It is mainly caused by low frequency pressure variations under high load and by the presence of geometric unevenness (high Kerb factor) on the inner side of the pipe. In order to avoid damage practical experience has shown that the safety coefficient for existing piping should be over 2 and preferably over 3. A significant reduction in corrosion probability can be achieved by inhibitors, whereby 0.1 Vol% O/sub 2/ additive has been shown to be most effective. The question of counter-effects of the remaining gas components remains open.

  10. Fatigue behavior of austenitic steels. Subproject. Mechanism oriented investigation of the fatigue behavior of austenitic steel X6CrNiNb1810 in the HCF and VHCF regime. Final report; Ermuedungsverhalten Austenit. Teilprojekt. Mechanismenorientierte Untersuchung des Ermuedungsverhaltens des austenitischen Stahles X6CrNiNb1810 im HCF- und VHCF-Bereich. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Sorich, A.; Smaga, M.; Eifler, D.

    2015-01-23

    In addition to load cycles in the Low Cycle Fatigue (LCF)-regime due to start up and shut down procedures of power plants, in some components additional high-frequency loadings in the High Cycle Fatigue (HCF)- and Very High Cycle Fatigue (VHCF)-regime occur. These loadings are induced e.g. by stresses due to thermal cyclic fluctuations and fluid dynamic processes. Therefore it is necessary to characterize experimentally the cyclic deformation behavior of metastable austenitic steels at operating temperature particularly in the HCF- and VHCF-regime and to develop a nondestructive method to detect fatigue processes. This joint research project was conducted in cooperation between the Institute of Materials Science and Engineering (WKK) of the University of Kaiserslautern and the Fraunhofer-Institute for Non-Destructive Testing (IZFP) in Saarbruecken. WKK was focused on experimental investigations to characterize the cyclic deformation behavior of the metastable austenitic steel in the HCF- and VHCF-range, taking into account cyclic hardening and softening processes and in particular to consider fatigue-induced changes in microstructure. The IZFP has focused on the development and application of a testing concept based on electromagnetic ultrasonic measurements. The isothermal cyclic deformation behavior of the metastable austenitic steel X6CrNiNb1810 (1.4550, AISI 347) at 300 C in the HCF-range is characterized by cyclic softening until specimen failure. At strain amplitudes of 0.10 % ≤ ε{sub a,t} ≤ 0.15 % and the stress amplitude σ{sub a} = 160 MPa cyclic softening is followed by cyclic hardening, which results in a significant increase in life time, up to the limiting number of cycles, which was defined at N{sub I} = 10{sup 7} in HCF-regime. The cyclic hardening is determined by a transformation induced phase formation from face-centered cubic (fcc) austenite to body-centered cubic (bcc) α{sup '}-martensite and/or in hexagonal (hcp) ε-martensite. In the VHCF-range also transformation induced martensite formation is observed. This transformation leads to the achievement of the limiting number of cycles N{sub I} = 5.10{sup 8} in the VHCF-range. The fatigue-related material behavior is characterized by microstructural investigations on light and scanning electron microscopy as well as by X-ray and transmission electron microscopic investigations. The focus of these studies is the transformation induced martensite formation, which significantly affects the cyclic deformation behavior and increases significantly the life time.

  11. Non-destructive detection of fatigue in austenitic steel X6CrNiNb1810 in the HCF and VHCF range. Final report; Zerstoerungsfreie Detektion der Ermuedung von austenitischem Stahl X6CrNiNb1810 im HCF- und VHCF-Bereich. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Seiler, Georg; Boller, Christian [Univ. des Saarlandes, Saarbruecken (Germany). Lehrstuhl fuer Zerstoerungsfreie Pruefung und Qualitaetsmanagement

    2014-12-31

    In addition to load cycles in the Low Cycle Fatigue (LCF)-regime due to start up and shut down procedures of power plants, in some components additional high-frequency loadings in the High Cycle Fatigue (HCF)- and Very High Cycle Fatigue (VHCF)-regime occur. These loadings are induced e.g. by stresses due to thermal cyclic fluctuations and fluid dynamic processes. Therefore it is necessary to characterize experimentally the cyclic deformation behavior of metastable austenitic steels at operating temperature particularly in the HCF- and VHCF-regime and to develop a nondestructive method to detect fatigue processes. This joint research project was conducted in cooperation between the Institute of Materials Science and Engineering (WKK) of the University of Kaiserslautern and the Chair of Non-Destructive Testing and Quality Assurance of Saarland University (LZfPQ). WKK was focused on experimental investigations of the cyclic deformation behavior of metastable austenitic steel in the HCF- and VHCF-range, taking into account cyclic hardening and softening processes and in particular to consider fatigue-induced changes in microstructure. The samples were taken from a real pressurized water reactor component (surgeline). LZfPQ has focused on the development and application of a testing concept based on electromagnetic ultrasonic measurements. Within this subproject, electromagnetic acoustic transducers (EMATs) for in situ Operation in WKK's fatigue testing equipment have been developed and assembled. Single-step fatigue tests at elevated temperature (300 C) were conducted both with total-stress and strain control. During the test, the fatigue specimens were characterized by EMAT ultrasound in transmission mode. Different sensor types and wavemodes were used. The transmission signal was evaluated in terms of time of flight and amplitude. Both measured values are seen to behave in a characteristic manner depending on the test duration and the mechanical measured value (stress or strain amplitude, respectively) and thus also depending on the fatigue state. In particular, early prediction of the specimen failure is possible on this basis. The EMAT approach is thus a potential method for non-destructive early fatigue detection within an aging management system for power plants and should be further pursued.

  12. Attempts to improve the fatigue characteristics of the austenitic steel X5CrNi18-10 in the temperature range of 25-600 C by mechanical boundary layer hardening; Zur Verbesserung des Ermuedungsverhaltens des austenitischen Stahls X5CrNi18-10 im Temperaturbereich 25-600 C durch mechanische Randschichtverfestigungsverfahren

    Energy Technology Data Exchange (ETDEWEB)

    Nikitin, Ivan

    2007-01-31

    Pieces of the austenitic steel X5CrNi18-10 whose boundary layers had been hardened by different methods were investigated with a view to their fatigue deformation characteristics in the temperature range of 25-600 degC. Parallel to this, microstructural and X-ray analyses provided deeper understanding of fatigue deformation. The microstructure was characterized, among others, by TEM. Boundary layers were solidified by rolling, by a combination of mechanical and thermal processes, by high-temperature rolling, and by laser shock solidification. The analyses focused on microstructural processes and on the intrinsic stress stability and provided important information on the fabrication of structural components with optimised life. (orig.)

  13. An investigation of the ignition probability and data analysis for the detection of relevant parameters of mechanically generated steel sparks in explosive gas/air-mixtures; Untersuchungen zur Zuendwahrscheinlichkeit und Datenanalyse zur Erfassung der Einflussgroessen mechanisch erzeugter Stahl-Schlagfunktion in explosionsfaehigen Brenngas/Luft-Gemischen

    Energy Technology Data Exchange (ETDEWEB)

    Grunewald, Thomas; Finke, Robert; Graetz, Rainer

    2010-07-01

    Mechanically generated sparks are a potential source of ignition in highly combustible areas. A multiplicity of mechanical and reaction-kinetic influences causes a complex interaction of parameters. It is only little known about their effect on the ignition probability. The ignition probability of mechanically generated sparks with a material combination of unalloyed steel/unalloyed steel and with an kinetic impact energy between 3 and 277 Nm could be determined statistically tolerable. In addition, the explosiveness of not oxidized particles at increased temperatures in excess stoichiometric mixtures was proven. A unique correlation between impact energy and ignition probability as well as a correlation of impact energy and number of separated particles could be determined. Also, a principle component analysis considering the interaction of individual particles could not find a specific combination of measurable characteristics of the particles, which correlate with a distinct increase of the ignition probability.

  14. Interrupting Chagas disease transmission in Venezuela A interrupção da transmissão da doença de Chagas na Venezuela

    Directory of Open Access Journals (Sweden)

    Alberto ACHÉ

    2001-02-01

    Full Text Available The interruption of vectorial transmission of Chagas disease in Venezuela is attributed to the combined effects of ongoing entomoepidemiological surveillance, ongoing house spraying with residual insecticides and the concurrent building and modification of rural houses in endemic areas during almost five decades. The original endemic areas which totaled 750,000 km², have been reduced to 365,000 km². During 1958-1968, initial entomological evaluations carried out showed that the house infestation index ranged between 60-80%, the house infection index at 8-11% and a house density index of 30-50 triatomine bugs per house. By 1990-98, these indexes were further reduced to 1.6-4.0%, 0.01-0.6% and 3-4 bugs per house respectively. The overall rural population seroprevalence has declined from 44.5% (95% C.I.: 43.4-45.3% to 9.2% (95% C.I.: 9.0-9.4% for successive grouped periods from 1958 to 1998. The annual blood donor prevalence is firmly established below 1%. The population at risk of infection has been estimated to be less than four million. Given that prevalence rates are stable and appropriate for public health programmes, consideration has been given to potential biases that may distort results such as: a geographical differences in illness or longevity of patients; b variations in levels of ascertainment; c variations in diagnostic criteria; and d variations in population structure, mainly due to appreciable population migration. The endemic areas with continuous transmission are now mainly confined to piedmonts, as well as patchy foci in higher mountainous ranges, where the exclusive vector is Rhodnius prolixus. There is also an unstable area, of which landscapes are made up of grasslands with scattered broad-leaved evergreen trees and costal plains, where transmission is very low and occasional outbreaks are reported.A interrupção da transmissão da doença de Chagas é atribuida aos efeitos conjuntos da vigilância soroepidemiol

  15. Evaluación de la actividad tóxica de los insecticidas piretroides deltametrina y lambdacihalotrina en dos poblaciones de campo de Rhodnius pallescens (Hemíptera: Reduviidae de Panamá

    Directory of Open Access Journals (Sweden)

    Lorenzo Cáceres

    2011-04-01

    Conclusiones. En ninfas de estadios I y V de ambas poblaciones de R. pallescens, se observó mediante los valores obtenidos de factor de resistencia que no existen ninguna diferencia significativa en el efecto tóxico de los insecticidas estudiados. Esto permite establecer que las dos cepas de R. pallescens son sensibles a los insecticidas deltametrina y lambdacihalotrina.

  16. donor-acceptor reactions: good bye to the laboratory jargon

    African Journals Online (AJOL)

    Temechegn

    appearance of silvery molten metals during the heating of ore-coal mixtures, Stahl concluded the. “transfer of .... Hydrogen chloride dissociates into ions to .... corrosion. Iron corrodes in moist air forming iron hydroxide,. Iron is thereby being.

  17. Monitoring of a novel bacterium, Lactobacillus thermotolerans, in ...

    African Journals Online (AJOL)

    user

    2012-08-28

    Aug 28, 2012 ... production and preservation of sausages and meat, in the fermentation of ... microorganisms in natural environments (Amann and. Schleifer, 1995). ..... Amann R, Binder B, Olson R, Chrisholm S, Devereux R, Stahl D (1990).

  18. Isolasi Dan Analisis Kimia Minyak Atsiri Dari Bunga Kecombrang (Etlingera Elatior) Dengan Gas Kromatografi-Spektrometer Massa (GC-MS) Dan Uji Aktivitas Anti Bakteri

    OpenAIRE

    Perangin Angin, Mawar Indah

    2016-01-01

    In this study has been treated isolation and analyze its chemical component of volatile oil of Etlingera e. obtained from district of Nang Belawan sub district of Simpang Empat in Karo Regency. The isolated volatile oil used Stahl tool. Chemical composition for each outcome of isolation was treated analysis using Gas chromatography Mass Spectrophotometer (GC-MS) device and Infra Red Spectrophotometer. The outcome isolation of Etlingera e.by distillation using Stahl device some 450 gram sa...

  19. Influence through Airpower Security Cooperation in Egypt and Pakistan: Lessons for Iraq

    Science.gov (United States)

    2007-12-01

    was a predictable outcome and casts doubt as to whether or not airpower security cooperation can realistically dissuade states from attempting to...in the Middle East and South Asia, ed. Shelly A. Stahl and Geoffrey Kemp (New York: St. Martin’s Press, 1992) 221-227. 48 airpower security...Policy Toward Arms Transfers to the Middle East,” in Arms Control and Weapons Proliferation in the Middle East and South Asia, ed. Shelly A. Stahl and

  20. Handbook of International alloy Compositions and Designations. Volume II. Superalloys

    Science.gov (United States)

    1978-12-01

    Aubert et Duval, 92200 Neuilly-sur-Seine, Paris, France C-0180 August Dreckshage Eisen und Stahl, 4800 Bielefeld, West Germany C-0021 Avesta Jernverks...Aktiebolag, 774 01 Avesta , Sweden B C-0087 Babcock & Wilcox, Beaver Falls, Pennsylvania 15010 C-0126 Bergische Stahl-lndustrie, (BSD 5630 Remscheid...C-0033) C-0021 Avesta Jernverks Aktiebolag, 774 01 Avesta , Sweden C-0022 Howmet Turbine Components Corporation, (Div. of PUG), Muskegon, Michigan

  1. Miocardite no macaco Cebus após inoculações repetidas com Schizotrypanum cruzi

    Directory of Open Access Journals (Sweden)

    C. Magarinos Torres

    1958-07-01

    Full Text Available Transmission of Chagas disease is realized through contamination of ocular conjunctiva, mucosa or skin with infected dejections eliminated by the insect vectors of Schizotrypanum cruzi (Triatoma infestans, Panstrongylus megistus and Rhodnius prolixus. The triatomid bugs live in holes and craks in the walls, in beds, behind trunks, etc. Found in primitive mud huts covered with thatched roofs, and so the human dwellers have many chances to contract the disease, reinfections being reasonably more to expect than a single inoculation. Experimental work reproducing those natural conditions is welcomed as some important features in the pathologic picture of the disease such as the extensive myocardial fibrosis seen in chronic cases are still incompletely known. Microscopic changes were studied in the heart muscle of seven Cebus monkeys infected by S. cruzi. This animal survives the acute stage of the disease and so is particularly suited to experiments of long duration in which several inoculations of S. cruzi are performed. Three different strains of S. cruzi isolated from acute cases of Chagas' disease were employed. One monkey was injected in the skin with infected blood and necropsied after 252 days. Two monkeys were three times, and one, eight times infected in skin, one of them with contaminated blood, and two with contaminated blood and dejections from infected bugs. The necropsies were performed after 35, 95 and 149 days. One monkey was three times inoculated through the intact ocular conjunctiva (one time with infected blood, two times with dejections from infected bugs, and one time through the wounded buccal mucosa, and necropsied after 134 days. Another monkey was six times inoculated, four times through the intact ocular conjunctiva (one time with contaminated blood, three times with dejections from infected bugs and two times injected in the skin with infected blood, and necropsied after 157 days. Finally, another monkey was nine times

  2. The impact of Chagas disease control in Latin America: a review.

    Science.gov (United States)

    Dias, J C P; Silveira, A C; Schofield, C J

    2002-07-01

    Discovered in 1909, Chagas disease was progressively shown to be widespread throughout Latin America, affecting millions of rural people with a high impact on morbidity and mortality. With no vaccine or specific treatment available for large-scale public health interventions, the main control strategy relies on prevention of transmission, principally by eliminating the domestic insect vectors and control of transmission by blood transfusion. Vector control activities began in the 1940s, initially by means of housing improvement and then through insecticide spraying following successful field trials in Brazil (Bambui Research Centre), with similar results soon reproduced in São Paulo, Argentina, Venezuela and Chile. But national control programmes only began to be implemented after the 1970s, when technical questions were overcome and the scientific demonstration of the high social impact of Chagas disease was used to encourage political determination in favour of national campaigns (mainly in Brazil). Similarly, large-scale screening of infected blood donors in Latin America only began in the 1980s following the emergence of AIDS. By the end of the last century it became clear that continuous control in contiguous endemic areas could lead to the elimination of the most highly domestic vector populations - especially Triatoma infestans and Rhodnius prolixus - as well as substantial reductions of other widespread species such as T. brasiliensis, T. sordida, and T. dimidiata, leading in turn to interruption of disease transmission to rural people. The social impact of Chagas disease control can now be readily demonstrated by the disappearance of acute cases and of new infections in younger age groups, as well as progressive reductions of mortality and morbidity rates in controlled areas. In economic terms, the cost-benefit relationship between intervention (insecticide spraying, serology in blood banks) and the reduction of Chagas disease (in terms of medical and

  3. The impact of Chagas disease control in Latin America: a review

    Directory of Open Access Journals (Sweden)

    JCP Dias

    2002-07-01

    Full Text Available Discovered in 1909, Chagas disease was progressively shown to be widespread throughout Latin America, affecting millions of rural people with a high impact on morbidity and mortality. With no vaccine or specific treatment available for large-scale public health interventions, the main control strategy relies on prevention of transmission, principally by eliminating the domestic insect vectors and control of transmission by blood transfusion. Vector control activities began in the 1940s, initially by means of housing improvement and then through insecticide spraying following successful field trials in Brazil (Bambui Research Centre, with similar results soon reproduced in São Paulo, Argentina, Venezuela and Chile. But national control programmes only began to be implemented after the 1970s, when technical questions were overcome and the scientific demonstration of the high social impact of Chagas disease was used to encourage political determination in favour of national campaigns (mainly in Brazil. Similarly, large-scale screening of infected blood donors in Latin America only began in the 1980s following the emergence of AIDS. By the end of the last century it became clear that continuous control in contiguous endemic areas could lead to the elimination of the most highly domestic vector populations - especially Triatoma infestans and Rhodnius prolixus - as well as substantial reductions of other widespread species such as T. brasiliensis, T. sordida, and T. dimidiata, leading in turn to interruption of disease transmission to rural people. The social impact of Chagas disease control can now be readily demonstrated by the disappearance of acute cases and of new infections in younger age groups, as well as progressive reductions of mortality and morbidity rates in controlled areas. In economic terms, the cost-benefit relationship between intervention (insecticide spraying, serology in blood banks and the reduction of Chagas disease (in terms

  4. Reseña Histórica de algunos estudios Colombianos sobre Trypanosoma rangeli

    Directory of Open Access Journals (Sweden)

    Hernando Groot Liévano

    2000-08-01

    Full Text Available

    Parecerá extraño que uno de los primeros artículos de esta revista no se refiera a la enfermedad de Chagas. Tanto es así que cuando el doctor Felipe Guhl tuvo la idea de llamarme para esta presentación, mi primera respuesta fue negativa porque, obviamente debería hablarse del Trypanosoma cruzi y no del Trypanosoma rangeli. El presente artículo es un breve recuento de mi experiencia con este parásito y su importancia dado que coexiste con el T. cruzi y que, en ocasiones la diferenciación morfológica entre los dos no es tan clara cuando se examinan preparaciones de sangre en “gota gruesa” de vertebrados o preparaciones del contenido intestinal de los insectos vectores, y además porque tiene ciertas relaciones inmunológicas que es necesario tener en cuenta para evitar posibles confusiones. Por otra parte, su distribución geográfica es muy amplia extendiéndose desde México hasta el Perú y el Brasil.

    El Trypanosoma rangeli, llamado así por un distinguido médico y posteriormente diplomático de Venezuela, el doctor Enrique Tejera, quien encontró en los chipos, o sea en los Rhodnius prolixus de Venezuela, un pequeño flagelado muy largo, bastante diferente del Trypanosoma cruzi y resolvió ponerle el nombre de Trypanosoma o Crithidia rangeli pues no estaba muy seguro del género en el cual debía colocarlo. Evidentemente, sólo había visto la morfología de estos flagelados en el intestino de los Rhodnius y por consiguiente no tenía ningún otro elemento para identi-ficarlos.

    Únicamente comprobó que eran diferentes del cruzi. ¿Por qué le dedicó su descubrimiento a Rangel? Creo que es importante que nosotros los latinoamericanos conozcamos bien los valores científicos que han habido en nuestros países y en vez de preocuparnos por las artificiales fronteras políticas, lo cual en nada contribuye al progreso de la ciencia, comencemos a tener claro conocimiento de lo que en todas estas naciones hermanas por

  5. Chromosome characterization of two varieties of Mangifera indica L.¹

    Directory of Open Access Journals (Sweden)

    Neiva Izabel Pierozzi

    2011-10-01

    Full Text Available Chromosome studies were performed in two varieties of Mangifera indica L. (mango, 'IAC-140 Espadona' and in its progenitor 'Espada Stahl'. Both varieties showed 2n=40 chromosomes though the karyotype formulae were 8m + 10sm + 2sm s for 'Stahl' and 7m + 11sm + 2sm s for 'IAC-140'. The varieties showed moderate karyotype asymmetry which was estimated according to four different indices. Both varieties exhibited three chromosome pairs with silver impregnation after NOR-banding. The number of nucleoli within interphase cells varied from one, the commonest, to eight. The nucleolus persistent phenomenon was observed in more than 22% of metaphase cells of both varieties, seeing that in 'Stahl', up to two nucleoli were evidenced. This variety also showed one nucleolus in several anaphase cells. The studies were suitable for evidencing diversity at chromosomal level between these two varieties.

  6. Synthesis of cholesterol 26. C{sup 14} (1961); Synthese du cholesterol {sup 14}C-26 (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Herbert, M; Pichat, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    Cholesterol 26 {sup 14}C is synthesized from methylmagnesium iodide {sup 14}C with a 48 per cent overall yield. Cholesterol is purified by chromatography on alumina. The various intermediates of the synthesis are characterized by thin-layer chromatography according to Stahl. (authors) [French] Le cholesterol {sup 14}C-26 est synthetise a partir d'iodure de methyl magnesium {sup 14}C, avec un rendement de 48 pour cent par rapport a l'iodure de methyl {sup 14}C mis en jeu. Le cholesterol est purifie par chromatographie sur alumine. Les intermediaires de la synthese sont caracterises par chromatographie en couche mince, selon Stahl. (auteurs)

  7. ALGUNAS INVESTIGACIONES DEL DR. GROOT EN LA REVISTA MEDICINA. RESEÑA HISTÓRICA DE ALGUNOS ESTUDIOS COLOMBIANOS SOBRE TRYPANOSOMA RANGELI

    Directory of Open Access Journals (Sweden)

    Hernando Groot Liévano

    2016-12-01

    Full Text Available

    Artículo publicado en la revista MEDICINA Vol. 22 (2 del año 2000.

    Parecerá extraño que uno de los primeros artículos de esta revista no se refiera a la enfermedad de Chagas. Tanto es así que cuando el doctor Felipe Guhl tuvo la idea de llamarme para esta presentación, mi primera respuesta fue negativa porque, obviamente debería hablarse del Trvpanosoma cruzi y no del Trypanosoma rangeli. El presente artículo es un breve recuento de mi experiencia con este parásito y su importancia dado que coexiste con el T. cruzi y que, en ocasiones, la diferenciación morfológica entre los dos no es tan clara cuando se examinan preparaciones de sangre en ‘gota gruesa’ de vertebrados o preparaciones del contenido intestinal de los insectos vectores, y además porque tiene ciertas relaciones inmunológicas que es necesario tener en cuenta para evitar posibles confusiones. Por otra parte, su distribución geográfica es muy amplia extendiéndose desde México hasta el Perú y el Brasil.

    El Trypanosoma rangeli fue llamado así por un distinguido médico y posteriormente diplomático de Venezuela, el doctor Enrique Tejera, quien encontró en los chipos, o sea en los Rhodnius prolixus de Venezuela, un pequeño flagelado muy largo, bastante diferente del T. cruzi y resolvió ponerle el nombre de Trypanosoma o Crithidia rangeli, pues no estaba muy seguro del género en el cual debía colocarlo. Evidentemente, sólo había visto la morfología de estos flagelados en el intestino de los Rhodnius y, por consiguiente, no tenía ningún otro elemento para identificarlos. Únicamente comprobó que eran diferentes del T. cruzi.

    ¿Por qué le dedicó su descubrimiento a Rangel? Creo que es importante que nosotros los latinoamericanos conozcamos bien los valores científicos que han habido en nuestros países y en vez de preocuparnos por las artificiales fronteras políticas, lo cual en nada contribuye al progreso de la

  8. Structural Behavior Under Precision Impact Tests

    Science.gov (United States)

    1996-08-01

    ASPECTS OF IMPACT TESTING The problem of impact between two bodies has been studied extensively (for example, Eibl 1987, Feyerabend 1988, Krauthammer...Concrete for Hazard Protection, Edinburgh, Scotland, pp. 175-186. Feyerabend , M., 1988, "Der harte Querstoss auf Stützen aus Stahl und Stahlbeton

  9. Advertising and Consumer Search in a Duopoly Model

    NARCIS (Netherlands)

    M.C.W. Janssen (Maarten); M.C. Non (Marielle)

    2005-01-01

    textabstractWe consider a duopoly in a homogenous goods market where part of the consumers are ex ante uninformed about prices. Information can come through two different channels: advertising and sequential consumer search. The model is similar to that of Robert and Stahl (1993) with two major (and

  10. Cognitive Theory within the Framework of an Information Processing Model and Learning Hierarchy: Viable Alternative to the Bloom-Mager System.

    Science.gov (United States)

    Stahl, Robert J.

    This review of the current status of the human information processing model presents the Stahl Perceptual Information Processing and Operations Model (SPInPrOM) as a model of how thinking, memory, and the processing of information take place within the individual learner. A related system, the Domain of Cognition, is presented as an alternative to…

  11. SNR 300 - no perpetuum mobile

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    It should breed more nuclear fuel than it needs for itself; it should produce cheap electricity - presumably it shall fulfill neither of these tasks, this 'Fast Breeder' at Kalkar. The State Secretary Mr. Stahl of the Bundesforschungsministerium had expressed it in the Bundestag: the breeding rate is 'not of the greatest importance' for the economic use of breeder reactors. (orig.) [de

  12. Examining Incidental Vocabulary Acquisition by Person-and Item-Level Factors in Secondary Students

    Science.gov (United States)

    Cooper, Jennifer LeeAnn

    2016-01-01

    Vocabulary knowledge is central to the process of reading comprehension (Cromely & Azevedo, 2007; Stahl & Nagy, 2005; Stanovich, 1986). The majority of our vocabulary knowledge is postulated to come from the process of incidental vocabulary acquisition (IVA) while reading (Nagy & Anderson, 1984). Prior studies have estimated an average…

  13. Nichteisenmetalle

    Science.gov (United States)

    Weißbach, Wolfgang

    Geringere Vorkommen in z. T. armen Erzen und dadurch aufwändige Verhüttung führen gegenüber Stahl zu höheren Preisen für NE-Metalle. Ihr Einsatz ist notwendig, wenn besondere Eigenschaften gefordert werden, die Stähle nicht erbringen.

  14. THYROCALCITONIN STUDIES IN ELASMOBRANCH FISH ...

    African Journals Online (AJOL)

    P. D. STAHL AND A. D. KENNY. Department Pharmacology and Space Sciences Research Centre,. University of Missouri, Columbia, Mo. INTRODUCTION. We recently reported a hypocalcaemic and hypophosphataemic action of mammalian thyro- caltitonin in the teleost fish Ictalurus melas (Louw, Sutton and Kenny 1967) ...

  15. Screening for Elder Abuse among Turkish Older People: Validity of the Hwalek-Sengstock Elder Abuse Screening Test (H-S "East")

    Science.gov (United States)

    Özmete, Emine; Megahead, Hamido A.

    2017-01-01

    Objective: This study aims to adapt "The Hwalek-Sengstock Elder Abuse Screening Test (H-S "East")" (Neale, Hwalek, Scott, Sengstock, & Stahl, 1991) to Turkish and to assess its validity and reliability while determining the factors that affect elder abuse. Method: The sample of the study is composed of 465 elderly women and…

  16. Service Learning: Flooding Students with Vocabulary through Read Alouds

    Science.gov (United States)

    Holmes, Kerry; Thompson, Judith

    2014-01-01

    In the spirit of the Steven Stahl 600 Book Kid Challenge, 90 preservice teachers engaged children in 36 read-aloud sessions for a vocabulary improvement service learning project. This article describes how the preservice teachers used narrative and informational books as a vehicle for rare-word vocabulary exposure for children ages 8-12.

  17. Meaning & inference in case of conflict

    NARCIS (Netherlands)

    Franke, M.; Balogh, K.

    2008-01-01

    This paper applies a model of boundedly rational "level-k thinking" (c.f. Stahl and Wilson, 1995; Crawford, 2003; Camerer, Ho and Chong, 2004) to a classical concern of game theory: when is information credible and what shall I do with it if it is not? The model presented here extends and

  18. A Framework for the Analysis of Collaborative and Interactive Elements in MOOCs

    DEFF Research Database (Denmark)

    Rasmus Kvist, Andersen,; Garp, Kristian; Nellemann, Kevin

    2014-01-01

    of collaborative knowledge construction processes and, as such, signs of learning (in line with the CSCL thinking of Laurillard, Stahl, Sorensen, and Salmon). This paper presents a study whose objective is to identify methods for analyzing and evaluating the nature of collaborative knowledge construction...

  19. Enfermedad de Chagas y Colonización en el Alto Catatumbo

    Directory of Open Access Journals (Sweden)

    Felipe Guhr

    1992-03-01

    Full Text Available

    Introducción
    El protozoario parásito Trypanosoma cruzi, agente causal de la enfermedad de Chagas, infecta alrededor de 10 millones de individuos en Latinoamérica pudiendo ocasionarse en algunos de ellos, patologías cardíacas o digestivas.

    En Colombia, el T.cruzi se detecta frecuentemente en el Valle del Río Magdalena en la región del Catatumbo, la Sierra Nevada de Santa Marta y los Llanos Orientales.

    Se estima que alrededor de17% de la población colombiana está infectada y cerca del 23% se encuentra bajo riesgo de adquirir la infección dependiendo de la distribución de los vectores (l.

    Se han reportado 17 especies de triatomineos en el país y en siete de ellas se ha demostrado la presencia del parásito. Rhodnius prolixus es el insecto vector de mayor distribución en las áreas endémicas debido a sus hábitos antropofílicos y domiciliarios (2.

    El esquema tradicional de la cadena epidemiológica de 1′. cruzi muestra que la transmisión estuvo primitivamente restringida a ciclos específicos en el ambiente selvático donde triatomineos silvestres acometían mamíferos pequeños y medianos en vastas extensiones del Continente Americano, sin que el hombre interviniera en este ciclo natural.

    Esta situación persiste hasta hoy en regiones vírgenes de América configurándose el carácter epidemiológico de una enzootia silvestre (figura 1.

    La presencia de T. cruzi parece no afectar significativamente a los triatomineos ni a los mamíferos silvestres naturales infectados, lo que sugiere un equilibrio entre las especies, fruto de largos períodos de adaptación. Es común encontrar mamíferos portadores de T. cruzi en el país; por ejemplo, se ha descrito más de un centenar de reservorios pertenecientes a especies diferentes (1.

    La existencia de la enfermedad de Chagas humana es un hecho puramente accidental. En la medida en que el hombre fue entrando en contacto con los focos

  20. LHCb Early Career Scientist Awards

    CERN Multimedia

    Patrick Koppenburg for the LHCb Collaboration

    2016-01-01

    On 15 September 2016, the LHCb collaboration awarded the first set of prizes for outstanding contributions of early career scientists.   From left to right: Guy Wilkinson (LHCb spokesperson), Sascha Stahl, Kevin Dungs, Tim Head, Roel Aaij, Conor Fitzpatrick, Claire Prouvé, Patrick Koppenburg (chair of committee) and Sean Benson. Twenty-five nominations were submitted and considered by the committee, and 5 prizes were awarded to teams or individuals for works that had a significant impact within the last year. The awardees are: Roel Aaij, Sean Benson, Conor Fitzpatrick, Rosen Matev and Sascha Stahl for having implemented and commissioned the revolutionary changes to the LHC Run-2 high-level-trigger, including the first widespread deployment of real-time analysis techniques in High Energy Physics;   Kevin Dungs and Tim Head for having launched the Starterkit initiative, a new style of software tutorials based on modern programming methods. “Starterkit is a group of ph...

  1. [Medecine and chemistry in the context of the Enlightenment: the thesis of the Lausanne physician Marc-Louis Vullyamoz].

    Science.gov (United States)

    Terrier, Georges

    2003-01-01

    The chemico-medical essay "De sale lactis essentiali" is a thesis presented in Leyden in 1756 by a physician from Lausanne, M.-L. Vullyamoz, to obtain the medical degree. It shows that chemistry has become a university science connected with medicine and that combustion was explained at that time by G. E. Stahl's theory of the phlogiston. It reminds us that the hypotheses of this German physician, which were part of the animistic doctrine, were widely adopted in Europe. In chemistry they began to fade in 1789 after the publication of Lavoisier's work on oxydation. Nevertheless, they have contributed to establish a modern science. In medicine Stahl's animism evolved towards vitalism, which survived in several forms. Vullyamoz's thesis, which presents chemical experiences intended to analyse and promote a popular medicine, is a testimony of the spirit of Enlightenment, which rejects dogmatism and tries to understand facts through observation and the use of reason.

  2. Journal of Biosciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Habitat change in Rhodnius spp may represent an environmental challenge for the development of the species, particularly when feeding frequency and population density vary in nature. To estimate the effect of these variables in stability on development, the degree of directional asymmetry (DA) and fluctuating asymmetry ...

  3. American Trypanosomiasis

    Science.gov (United States)

    2011-06-01

    infected reduviid bugs, including Triatoma sp, Panstron- gylus sp, and Rhodnius sp (Figs 2.9 & 2.10). These large bugs (sometimes called kissing or...cause abor- tion of the fetus or its premature delivery by the infected mother . Congenitally acquired infection may be asymptom- atic or it may

  4. Letterman Army Institute of Research Annual Research Progress Report, FY 1981.

    Science.gov (United States)

    1981-10-01

    five species of mosquitoes. These compounds were tested against sand flies ( Lutzomyia longipalpis), fleas (Xenopsylla cheopis ) and bugs (Rhodnius...BUESCHER, M.D., L.C. RUTLEDGE, R.A. WIRTZ, K.B. GLACKIN, and M.A. MOUSSA. Laboratory tests of repellents against Lutzomyia longipalpis (Diptera

  5. KOMPOSISI KIMIA MINYAK ATSIRI BUAH SIRIH HIJAU (PIPER BETLE L), KEMUKUS (PIPER CUBEBA L) DAN CABE JAWA (PIPER RETROFRACTUM VAHL)

    OpenAIRE

    M. Widyo Wartono; Ahmad Ainurofiq; Maya Ismaniar

    2014-01-01

    Tumbuhan genus Piper mempunyai kandungan minyak atsiri hampir disemua bagiannya, namun komposisi kimianya belum semua dilaporkan. Pada laporan ini kami melakukan isolasi dan identifikasi senyawa kimia minyak atsiri pada bagian buah tumbuhan Piper. Isolasi minyak atsiri buah Piper dilakukan dengan destilasi air menggunakan destilasi Stahl dan analisis komposisi kimia dengan kromatografi gas-spektroskopi masa (GC-MS). Kandungan minyak atsiri buah sirih hijau (Piper betle) 1,4% (v/b), cabe jawa ...

  6. ISOLASI DAN IDENTIFIKASI KOMPONEN KIMIA MINYAK ATSIRI DAUN LEGUNDI (Vitex trifolia L.) DAN UJI AKTIVITAS ANTIMIKROBANYA

    OpenAIRE

    Mufidah, S.Si., M.Si., Apt.

    2004-01-01

    Dalam rangka pengembangan obat tradisional, telah dilakukan isolasi dan uji aktivitas antimikroba minyak atsiri daun legundi (Vitex trifolia, L.) familia Verbenaceae. Penelitian ini bertujuan untuk mengisolasi, menganalisis dan menguji aktivitas antimikroba minyak atsiri daun legundi. Isolasi dilakan dengan alat destilasi Stahl, diperoleh minyak atsiri sebanyak 0,02% v/b daun segar dan 0,08% v/b daun kering. Dari interpretasi data GC-MS tampak adanya 1,8 ???Cineole (17,83%), ???-terpiny...

  7. Isolasi Dan Analisis Komponen Kimia Minyak Atsiri Dari Daun Tumbuhan Binara (Artemisia Vulgaris L.) Di Daerah Kecamatan Sibolangit Kabupaten Deli Serdang Dengan GC-MS Dan FT-IR

    OpenAIRE

    Sembiring, Dalan Malem

    2011-01-01

    In this study has been treated isolation and analyze its chemical component of volatile oil of Binara plant (Artemicia Vulgaris L. ) obtained from District of Sibolangit in Deli Serdang Regency. The isolated volatile oil was conducted over fresh leaves of Binara plant (Artemicia Vulgaris, L) with distillation along with water used Stahl tool and compared it with distillation method by steam. Chemical composition for each outcome of isolation was treated analysis using Gas Chromatography Ma...

  8. The Economics of Starvation

    DEFF Research Database (Denmark)

    Stahl, Rune Møller

    2016-01-01

    Stahl investigates the role of liberal economics in the formulation of the disastrous famine policy of the British colonial administration in nineteenth-century India, where millions of Indians starved to death in a series of famines. The chapter examines the influential debates around the Great....... The hegemonic position of free trade ideas and economic liberalism allowed for proponents of a hard laissez-faire line to mobilize considerable intellectual resources, from Adam Smith to Ricardo, to overcome humanitarian critiques....

  9. Index of International Publications in Aerospace Medicine

    Science.gov (United States)

    2014-05-01

    University, 1974. Gerathewohl ST. Principles of Bioastronautics. Englewood Cliffs, NJ, USA: Prentice-Hall, 1963. Gibson DC. Commercial Space Tourism ...College of Sports Medicine, 1996. Jenkins M. Human-Rating Requirements. Houston, TX, USA: Lyndon B. Johnson Space Center, 1998. Johnson B, May GL...USA: U.S. Government Printing Office, 2000. Spencer J, Rugg KL. Space Tourism : Do You Want to Go? Burlington, Canada: Apogee Books, 2004. Stahle J

  10. Steel pipelines standards for fittings and joint accessories

    CERN Document Server

    DIN

    2013-01-01

    Die 1. Auflage von DIN Handbook 15/6 erweitert die DIN Handbook-Reihe um den Themenbereich Fittings für verschiedene Montagetechniken. Es enthält in englischer Übersetzung die wesentlichen Normen über Lötfittings aus Kupfer, Temperguss-Fittings, Fittings aus Stahl und Kunststofffittings. Abgerundet wird der Inhalt durch ergänzende Normen, Begriffe und Grundnormen. Reihe DIN_Handbook - 15/6

  11. Vitamin C acts as radiation-protecting agent

    International Nuclear Information System (INIS)

    Platzer, Isabel; Getoff, Nikola

    1998-01-01

    It is well known that vitamin C (L-ascorbic acid) is a very efficient, water soluble antioxidant. Its multifunctional biological and biochemical activities are rather well established in the last few decades (e.g. Sies and Stahl, 1995; Meydani et al., 1995; NRC, 1989. In the present letter we are reporting briefly the pronounced radiation-protecting properties of ascorbate (AH - ) observed on bacteria (E. coli AB1157) as well as on cultured cells (SCC VII, eukaryotic cells)

  12. Umfrageforschung: Entscheidungsgrundlage für Politik und Wissenschaft

    OpenAIRE

    2011-01-01

    "Der vorliegende Tagungsband dokumentiert die Beiträge der wissenschaftlichen Tagung 'Umfrageforschung - Entscheidungsgrundlage für Politik und Wissenschaft', die am 30. Juni und 1. Juli 2011 gemeinsam vom Statistischen Bundesamt, dem ADM Arbeitskreis Deutscher Markt- und Sozialforschungsinstitute e.V. und der Arbeitsgemeinschaft Sozialwissenschaftlicher Institute e.V. (ASI) in Wiesbaden durchgeführt wurde." (Autorenreferat). Inhaltsverzeichnis: Christian König, Matthias Stahl, Erich Wiegand:...

  13. U.S. Air Force Installation Restoration Program. Phase 1. Records Search. Air National Guard, Camp Edwards (ARNG), U.S. Air Force and Veteran’s Administration Facilities at Massachusetts Military Reservation, Massachusetts. Task 6

    Science.gov (United States)

    1986-12-11

    MMR main gate (see Figure 3.2-1). In those ponds Umbrella-grass (Guirena-pumila) and Hyssop Hedge- nettle (Stachys- hyssopifolia) were found. The other...has conducted research in Buildings 286 and 240. From 1963 to 1969, the lab tested insecticides for private companies. Residuals from the 4...Airport Turf Insecticidal Treatments for Japanese Beetle and European Chafer, Eastern Region. Stahl, Ralph G., Joachim G. Liehr, and Ernst M. Davis. 1984

  14. Distribuição espacial de populações de triatomíneos (Hemiptera: Reduviidae em palmeiras da espécie Mauritia flexuosa no Distrito Federal, Brasil Spatial distribution of Triatominae populations (Hemiptera: Reduviidae in Mauritia flexuosa palm trees in Federal District of Brazil

    Directory of Open Access Journals (Sweden)

    Rodrigo Gurgel-Gonçalves

    2004-06-01

    Full Text Available Para determinar e analisar a distribuição espacial de populações silvestres de triatomíneos no Distrito Federal, Brasil, foram amostradas 150 palmeiras da espécie Mauritia flexuosa em seis veredas de diferentes paisagens (silvestre, rural e periurbana na estação chuvosa. Os triatomíneos foram identificados morfologicamente, separados por sexo e estadio ninfal e examinados para verificar infecção por Trypanosoma cruzi e Trypanosoma rangeli. Vinte e oito (18,6% palmeiras estavam infestadas por Rhodnius neglectus e 14 (9,5% por Psammolestes tertius. A freqüência dessas espécies em palmeiras com e sem ninhos foi significativamente diferente, sendo superior nas palmeiras com ninhos de aves e mamíferos na copa. O maior número médio de insetos/palmeira foi observado nas áreas rurais, com estimativas de até 838 insetos/hectare. A composição etária das espécies apresentou um padrão diferente, Rhodnius neglectus com predomínio de ninfas e Psammolestes tertius com predomínio de adultos, sendo que muitos ovos de Rhodnius neglectus foram coletados indicando um evento reprodutivo em fevereiro de 2003. Entre os ninhos encontrados nas palmeiras, o do pássaro Phacellodomus ruber (Furnariidae apresentou as maiores abundâncias de triatomíneos, ocorrendo em 42% das palmeiras. A abundância relativa de Rhodnius neglectus e Psammolestes tertius foi maior em áreas rurais que possuíram maior número de ninhos nas palmeiras e menor densidade de palmeiras por hectare. Nenhum dos 96 triatomíneos examinados estava infectado por Trypanosoma cruzi ou Trypanosoma rangeli, apesar de encontrarmos infecção de Rhodnius neglectus por esses parasitas em estudos anteriores.To determine and analyze the distribution of Triatominae sylvatic populations in the Federal District of Brazil, 150 Mauritia flexuosa palm trees were sampled in six veredas of different landscapes (sylvatic, rural and peri-urban in the rainy season. Triatomines were

  15. Triatominos del departamento de San Martín, Perú, 2005

    OpenAIRE

    Cáceres, Abraham; Zavaleta, Gina; Ruiz, Juan; Vega, Silvia; Arevalo, Heriberto; Náquira, César

    2005-01-01

    La presencia de los triatominos transmisores de Trypanosoma cruzi y Trypanosoma rangeli ha sido reportada en todos los departamentos del Perú, excepto en Huancavelica. En el sudoeste, el Triatoma infestans es de hábitos domiciliarios y en la zona norte y nororiente hay numerosas especies de hábitos intradomiciliarios (Panstrongylus herreri, Rhodnius ecuadoriensis) aunque ocasionalmente ingresan a las viviendas (T. Carroni, P. geniculatus, P. chinai), mientras que otras son de hábitos silvestr...

  16. Attraction of Chagas disease vectors (Triatominae) to artificial light sources in the canopy of primary Amazon rainforest.

    Science.gov (United States)

    Castro, Marcelo C M; Barrett, Toby V; Santos, Walter S; Abad-Franch, Fernando; Rafael, José A

    2010-12-01

    Adult triatomines occasionally fly into artificially lit premises in Amazonia. This can result in Trypanosoma cruzi transmission to humans either by direct contact or via foodstuff contamination, but the frequency of such behaviour has not been quantified. To address this issue, a light-trap was set 45 m above ground in primary rainforest near Manaus, state of Amazonas, Brazil and operated monthly for three consecutive nights over the course of one year (432 trap-hours). The most commonly caught reduviids were triatomines, including 38 Panstrongylus geniculatus, nine Panstrongylus lignarius, three Panstrongylus rufotuberculatus, five Rhodnius robustus, two Rhodnius pictipes, one Rhodnius amazonicus and 17 Eratyrus mucronatus. Males were collected more frequently than females. The only month without any catches was May. Attraction of most of the known local T. cruzi vectors to artificial light sources is common and year-round in the Amazon rainforest, implying that they may often invade premises built near forest edges and thus become involved in disease transmission. Consequently, effective Chagas disease prevention in Amazonia will require integrating entomological surveillance with the currently used epidemiological surveillance.

  17. Attraction of Chagas disease vectors (Triatominae to artificial light sources in the canopy of primary Amazon rainforest

    Directory of Open Access Journals (Sweden)

    Marcelo CM Castro

    2010-12-01

    Full Text Available Adult triatomines occasionally fly into artificially lit premises in Amazonia. This can result in Trypanosoma cruzi transmission to humans either by direct contact or via foodstuff contamination, but the frequency of such behaviour has not been quantified. To address this issue, a light-trap was set 45 m above ground in primary rainforest near Manaus, state of Amazonas, Brazil and operated monthly for three consecutive nights over the course of one year (432 trap-hours. The most commonly caught reduviids were triatomines, including 38 Panstrongylus geniculatus, nine Panstrongylus lignarius, three Panstrongylus rufotuberculatus, five Rhodnius robustus, two Rhodnius pictipes, one Rhodnius amazonicus and 17 Eratyrus mucronatus. Males were collected more frequently than females. The only month without any catches was May. Attraction of most of the known local T. cruzi vectors to artificial light sources is common and year-round in the Amazon rainforest, implying that they may often invade premises built near forest edges and thus become involved in disease transmission. Consequently, effective Chagas disease prevention in Amazonia will require integrating entomological surveillance with the currently used epidemiological surveillance.

  18. Introductory modern algebra a historical approach

    CERN Document Server

    Stahl, Saul

    2013-01-01

    Praise for the First Edition ""Stahl offers the solvability of equations from the historical point of view...one of the best books available to support a one-semester introduction to abstract algebra.""-CHOICE Introductory Modern Algebra: A Historical Approach, Second Edition presents the evolution of algebra and provides readers with the opportunity to view modern algebra as a consistent movement from concrete problems to abstract principles. With a few pertinent excerpts from the writings of some of the greatest mathematicians, the Second Edition uniquely facilitates the understanding of pi

  19. Analisis Komponen Kimia Dan Uji Aktivitas Antibakteri Minyak Atsiri Daun Pinus (Pinus Merkusii Jungh.Et Devries) Dari Kabupaten Samosir

    OpenAIRE

    Siringo-Ringo, Mawar

    2015-01-01

    Essential oil of pinus leaves (Pinus merkusii Jungh.et deVries) have been isolated by hydrodestilation method using Stahl. Pinus leaves have destilated for five hours roduced essential oil 0.1531% (w/w). The results of the analyse use GC-MS showed 23 peaks and can be identified 20 compounds and have five major compounds are Limonene (22.72%), α-Pinene (17.53%), β-Caryophyllene (16.76%), β-Ocimene (14.68%), and Germacren-d (11.24%). Antibacterial activity of the test have been done using ag...

  20. Robert Boyle, Transmutation, and the History of Chemistry before Lavoisier: A Response to Kuhn.

    Science.gov (United States)

    Newman, William R

    2014-01-01

    In an influential article of 1952, Thomas Kuhn argued that Robert Boyle had little or no influence on the subsequent development of chemistry. This essay challenges Kuhn's view on two fronts. First, it shows that Johann Joachim Becher developed his hierarchical matter theory under the influence of Boyle and then transmitted it to the founder of the phlogiston theory, G. E. Stahl. Second, this essay argues that transmutational matter theories were not necessarily opposed to the existence of stable chemical species, pace Kuhn. Boyle's corpuscular theory descended largely from the tradition of "chymical atomism," which often advocated both chrysopoeia and the reality of robust chemical substances.

  1. Identifikasi Komponen Kimia Minyak Atsiri Daun Bunga Tahi Ayam (Tagetes erecta L) Serta Uji Aktivitas Antibakteri Dan Antioksidan

    OpenAIRE

    Pinem, Denny Anta Dona Putra

    2012-01-01

    Essential Oil of the tagetes leaves (Tagetes erecta L) have isolated with hydrodestillation method use stahl. Tagetes leaves have hydrodestillation during ±4-5 hours resulting essential oil amount 0,03 % (v/b). Chemical component in essential oil of tagetes leaves have analysed use GC-MS shown there were fifteen compounds and the major are Piperitone (52,94%), Eugenol (9,18%), Limonen (8,85%), 1,3,7-Octatriene-3,7,-dimethyl (6,70%), Terpinolene (6,25%), and 2,4-Cycloheptadiene-1-on(5,68%). An...

  2. Measurement of gamma radioactivity in steel

    International Nuclear Information System (INIS)

    Wachtendonk, H.J. von; Flock, J.; Grientschnig, D.; Kircher, T.; Kroos, J.; Mertens, S.; Mueller, J.; Puchmayr, J.; Schlothmann, B.J.; Schmitz, H.U.; Troebs, V.; Unger, H.

    1999-01-01

    The steel industry is being confronted increasingly with radioactive scrap from dismantled nuclear facilities. The clearance and release regulations that exist around the world differ very greatly and are difficult to implement. A 'radioactivity measurement' working group has therefore been set up at VDEh to clarify how radioactive measurements can be integrated into the day-to-day production routine. Operating results obtained at Thyssen Krupp Stahl AG with a gamma-ray spectrometer indicate a possibility for the simple detection of radioactive contamination. (orig.) [de

  3. Spatiotemporal variability in archaeal communities of tropical coastal waters

    Digital Repository Service at National Institute of Oceanography (India)

    Singh, S.K.

    properties on SST biases and the South Asian summer monsoon in a coupled GCM. Clim Dyn 39:811–826 Urakawa H, Martens-Habbena W, Stahl DA (2010) High abundance of ammonia-oxidizing archaea in coastal waters, determined using a modified DNA extraction method...- ments suggests that archaea play a major role in the global nitrification process (Francis et al. 2005; Prosser and Nicol 2008; Wuchter et al. 2006). Denaturing gradient gel electrophoresis (DGGE) is among the reliable techniques for microbial...

  4. Distribution of triatomine species in domestic and peridomestic environments in central coastal Ecuador

    Science.gov (United States)

    Villacís, Anita G.; Moncayo, Ana L.; Ocaña-Mayorga, Sofia; Yumiseva, Cesar A.; Baus, Esteban G.

    2017-01-01

    Background Although the central coast of the Ecuador is considered endemic for Chagas disease, few studies have focused on determining the risk of transmission in this region. In this study we describe the triatomine household infestation in Manabí province (Central Coast region), determine the rate of Trypanosoma cruzi infection and study the risk factors associated with infestation by Rhodnius ecuadoriensis. Methodology/Principal findings An entomological survey found three triatomine species (Rhodnius ecuadoriensis, Panstrongylus rufotuberculatus and P. howardi) infesting domiciles in 47.4% of the 78 communities visited (total infestation rate of 4.5%). Four percent of domiciles were infested, and nymphs were observed in 77% of those domiciles. The three species were found in altitudes below 500 masl and in all ecological zones except cloud forest. Within the domicile, we found the three species mostly in bedrooms. Rhodnius ecuadoriensis and P. rufotuberculatus were abundant in bird nests, including chicken coops and P. howardi associated with rats in piles of bricks, in the peridomicile. Triatomine infestation was characterized by high rates of colonization, especially in peridomicile. Flagelates infection was detected in only 12% of the samples by microscopy and Trypanosoma cruzi infection in 42% of the examined triatomines by PCR (n = 372). The most important risk factors for house infestation by R. ecuadoriensis were ecological zone (w = 0.99) and presence of chickens (w = 0.96). Determinants of secondary importance were reporting no insecticide applications over the last twelve months (w = 0.86) and dirt floor (w = 0.70). On the other hand, wood as wall material was a protective factor (w = 0.85). Conclusion/Significance According the results, approximately 571,000 people would be at high risk for T. cruzi infection in Manabí province. A multidisciplinary approximation and the adhesion to a periodic integrated vector management (IVM) program are essential

  5. Distribution of triatomine species in domestic and peridomestic environments in central coastal Ecuador.

    Directory of Open Access Journals (Sweden)

    Mario J Grijalva

    2017-10-01

    Full Text Available Although the central coast of the Ecuador is considered endemic for Chagas disease, few studies have focused on determining the risk of transmission in this region. In this study we describe the triatomine household infestation in Manabí province (Central Coast region, determine the rate of Trypanosoma cruzi infection and study the risk factors associated with infestation by Rhodnius ecuadoriensis.An entomological survey found three triatomine species (Rhodnius ecuadoriensis, Panstrongylus rufotuberculatus and P. howardi infesting domiciles in 47.4% of the 78 communities visited (total infestation rate of 4.5%. Four percent of domiciles were infested, and nymphs were observed in 77% of those domiciles. The three species were found in altitudes below 500 masl and in all ecological zones except cloud forest. Within the domicile, we found the three species mostly in bedrooms. Rhodnius ecuadoriensis and P. rufotuberculatus were abundant in bird nests, including chicken coops and P. howardi associated with rats in piles of bricks, in the peridomicile. Triatomine infestation was characterized by high rates of colonization, especially in peridomicile. Flagelates infection was detected in only 12% of the samples by microscopy and Trypanosoma cruzi infection in 42% of the examined triatomines by PCR (n = 372. The most important risk factors for house infestation by R. ecuadoriensis were ecological zone (w = 0.99 and presence of chickens (w = 0.96. Determinants of secondary importance were reporting no insecticide applications over the last twelve months (w = 0.86 and dirt floor (w = 0.70. On the other hand, wood as wall material was a protective factor (w = 0.85.According the results, approximately 571,000 people would be at high risk for T. cruzi infection in Manabí province. A multidisciplinary approximation and the adhesion to a periodic integrated vector management (IVM program are essential to guarantee sustainable preventive and control

  6. Sexual distinction between 5th instar nymphs of six species of Triatominae (Hemiptera, Reduviidae

    Directory of Open Access Journals (Sweden)

    João Aristeu da Rosa

    1992-06-01

    Full Text Available The aim of this paper is to present the analysis of sexual morphological differences observed in 5th instar nymphs of the following species: Panstrongylus megistus; Rhodnius neglectus; Triatoma brasiliensis; T. infestans; T. matogrosensis and T. tibiamaculata. Male and female nymphs were examined and photographed with a Scanning Electron Microscope. The 9th segment dimensions of dorsal and ventral faces were determined through a Profile Projector. Results and statistical analysis showed significant differences: the 9th sternite is significantly broader in male than female nymphs, while in five species; tergites in female nymphs are broad and in male are narrow.

  7. [Triatominae and Cactaceae: a risk for the transmission of the American trypanosomiasis in the peridomicilary space (Northeast Brazil)].

    Science.gov (United States)

    Emperaire, L; Romaña, C A

    2006-06-01

    Field observations carried in semi-arid Brazil Northeast point out the frequent association, in the peridomiciliary space, between a cactus, Cereus jamacaru, the occurrence of nests in its branches and the occurrence of two species of insects vectors of Trypanosoma cruzi, pathogenic agent of Chagas disease: Rhodnius neglectus and Triatoma pseudomaculata. The analysis of the architectural variables of this Cactaceae shows that the presence of nests, and thus of insects, depends on the traditional practices of management of this cactus. This study underlines the relevance of an integrated approach of the ecology of Triatominae for the identification of factors of risk.

  8. Innovations for vehicle weight savings; Innovationen zur Gewichtseinsparung bei Kraftfahrzeugen

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, W.C. [Budd Technical Center, Auburn Hills, MI (United States)

    1999-04-01

    konventionellen Stahl ueber hoch- und hoechstfeste Staehle, Aluminiumguss, -blech und -strangpressprofile bis hin zu hochwertigen Kunststoffen, wie SMC und SRIM, werden Leichtbau-Problemloesungen fuer Karosserie und Fahrwerk entwickelt und der Automobilindustrie angeboten. Das Leichtbaupotential der diversen Werkstoffe wird darueber hinaus durch den Einsatz modernster Fertigungsverfahren, wie z.B. das Innenhochdruckumformen von Stahl und Aluminium, Tailored Blanks aus Stahl und die Klebetechnik bei Aluminium, weitgehend ausgeschoepft. (orig.)

  9. Methods of Approximation Theory in Complex Analysis and Mathematical Physics

    CERN Document Server

    Saff, Edward

    1993-01-01

    The book incorporates research papers and surveys written by participants ofan International Scientific Programme on Approximation Theory jointly supervised by Institute for Constructive Mathematics of University of South Florida at Tampa, USA and the Euler International Mathematical Instituteat St. Petersburg, Russia. The aim of the Programme was to present new developments in Constructive Approximation Theory. The topics of the papers are: asymptotic behaviour of orthogonal polynomials, rational approximation of classical functions, quadrature formulas, theory of n-widths, nonlinear approximation in Hardy algebras,numerical results on best polynomial approximations, wavelet analysis. FROM THE CONTENTS: E.A. Rakhmanov: Strong asymptotics for orthogonal polynomials associated with exponential weights on R.- A.L. Levin, E.B. Saff: Exact Convergence Rates for Best Lp Rational Approximation to the Signum Function and for Optimal Quadrature in Hp.- H. Stahl: Uniform Rational Approximation of x .- M. Rahman, S.K. ...

  10. Flow Cytometry-Assisted Cloning of Specific Sequence Motifs from Complex 16S rRNA Gene Libraries

    DEFF Research Database (Denmark)

    Nielsen, Jeppe Lund; Schramm, Andreas; Bernhard, Anne E.

    2004-01-01

    for Systems Biology,3 Seattle, Washington, and Department of Ecological Microbiology, University of Bayreuth, Bayreuth, Germany2 A flow cytometry method was developed for rapid screening and recovery of cloned DNA containing common sequence motifs. This approach, termed fluorescence-activated cell sorting......  FLOW CYTOMETRY-ASSISTED CLONING OF SPECIFIC SEQUENCE MOTIFS FROM COMPLEX 16S RRNA GENE LIBRARIES Jeppe L. Nielsen,1 Andreas Schramm,1,2 Anne E. Bernhard,1 Gerrit J. van den Engh,3 and David A. Stahl1* Department of Civil and Environmental Engineering, University of Washington,1 and Institute......-assisted cloning, was used to recover sequences affiliated with a unique lineage within the Bacteroidetes not abundant in a clone library of environmental 16S rRNA genes.  ...

  11. Implicit misattribution of evaluative responses: contingency-unaware evaluative conditioning requires simultaneous stimulus presentations.

    Science.gov (United States)

    Hütter, Mandy; Sweldens, Steven

    2013-08-01

    Recent research has shown that evaluative conditioning (EC) procedures can change attitudes without participants' awareness of the contingencies between conditioned and unconditioned stimuli (Hütter, Sweldens, Stahl, Unkelbach, & Klauer, 2012). We present a theoretical explanation and boundary condition for the emergence of unaware EC effects based on the implicit misattribution of evaluative responses from unconditioned to conditioned stimuli. We hypothesize that such misattribution is only possible when conditioned and unconditioned stimuli are perceived simultaneously. Therefore we manipulate the simultaneity of the stimulus presentations and apply a process dissociation procedure to distinguish contingency-aware from contingency-unaware EC effects. A multinomial model indicates that with sequential presentations, EC effects do not occur without contingency awareness. However, unaware EC effects do occur with simultaneous presentations. The findings support dual-process theories of learning. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  12. New superhard boride composite materials. Part 1; Neue superharte Borid-Verbundwerkstoffe. Teil 1

    Energy Technology Data Exchange (ETDEWEB)

    Zachariev, Z.

    2001-07-01

    Contents: Investigations of diffusion coupling between steels and borides (ZrB{sub 2}, TiB{sub 2}, CrB, MoB); Diffusion saturation of armco iron inpowdered borides; Gaseous phase transport intensivation of the transition metal using suitable activators (vapour phase process); boron circonisation of steels; High-temperature oxidation studies on boride composite coatings on iron and steel; Corrosion resistance of boride coated iron base composites; Superhard boride coatings on hard metals and on cermet plates with reduced tungsten contents. [German] Dieser Beitrag ist wie folgt gegliedert: Untersuchung der Diffusionskopplung zwischen Staehlen und den Boriden (ZrB{sub 2}, TiB{sub 2}, CrB, MoB); Diffusionssaettigung von Armcoeisen in Pulverboride; Gasphasentransport-Intensivierung des Uebergangsmetalls mittels geeigneter Akivatoren (vapour phase process); Borzirkonieren von Staehlen; Hochtemperaturoxidationuntersuchungen von Borid-Composite-Schichten auf Eisen und Stahl; Korrosionsbestaendigkeit der boridbeschichteten Verbundwerkstoffe auf Eisenbasis; Superharte Boridbeschichtungen auf Hartmetall und auf Metallkeramikplatten mit reduziertem Wolframgehalt.

  13. Comparative studies on ultrasonic, friction, laser and resistance pressure welding of NiTi shape memory alloys with high-alloy steels. Final report; Vergleichende Untersuchungen zum Ultraschall-, Reib-, Laserstrahl- und Widerstandspressschweissen von NiTi-Shape-Memory-Metall mit hochlegierten Staehlen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Zuckschwerdt, K.

    2000-04-01

    The suitability of different welding techniques for welding of NiTi shape memory alloys with high-alloy steel (C12CrNi17-7, X5CrNiNb19-9, X20Cr13) was investigated. The quality of the welds was analyzed using mechanical-technological, fractographic, metallographic and electron microscopy analysis. [German] Ziel dieses Forschungsvorhabens ist es, die Eignung der einzelnen Schweissverfahren fuer das Fuegen von NiTi-Formgedaechtnislegierungen mit hochlegiertem Stahl (X12CrNi17-7, X5CrNiNb19-9, X20Cr13) darzustellen und zu beurteilen. Die Qualitaet der Fuegeverbindungen wird mit Hilfe mechanisch-technologischer, fraktographischer, metallographischer und elektronenmikroskopischer Untersuchungen bewertet.

  14. How to treat tremor.

    Science.gov (United States)

    Rektor, Ivan; Rektorová, Irena; Suchý, Václav

    2004-05-01

    This paper presents an example of 18(th) century medical thinking. The author, Dr Georg Ernst Stahl (1659-1734) was the founder of the phlogiston theory in the field of chemistry, a medical professor, and a court physician in Saxony and Prussia. His description includes a definition of tremor, the internal and external causes of tremor, the types of tremor, the diagnostic and prognostic signs, and the treatment. From a present (contemporary) point of view, some compounds that were then used in treatment may have had a limited therapeutic effect on some kinds of tremor. Protopin has an anticholinergic and GABA-ergic effect, and rhoeadin (tetrahydrobenzazepin) may have had an effect similar to that of neuroleptics. Nevertheless, it is not clear whether the recommended quantity of these compounds was sufficient for a clinical effect. Most of the prescribed drugs could only have had a placebo effect.

  15. Activity, Microenvironments, and Community Structure of Aerobic and Anaerobic Ammonium Oxidizing Prokaryotes in Estuarine Sediment (Randers Fjord, DK)

    DEFF Research Database (Denmark)

    Schramm, Andreas; Revsbech, Niels Peter; Dalsgaard, Tage

    2006-01-01

    ACTIVITY, MICROENVIRONMENTS, AND COMMUNITY STRUCTURE OF AEROBIC AND ANAEROBIC AMMONIUM OXIDIZING PROKARYOTES IN ESTUARINE SEDIMENT (RANDERS FJORD, DK) A. Schramm 1, N.P. Revsbech 1, T. Dalsgaard 2, E. Piña-Ochoa 3, J. de la Torré 4, D.A. Stahl 4, N. Risgaard-Petersen 2 1 Department of Biological...... conversion of ammonium with nitrite to N2, is increasingly recognized as link in the aquatic nitrogen cycle. However, factors regulating the occurrence and activity of anammox bacteria are still poorly understood. Besides the influence of abiotic factors, anammox might be controlled by either aerobic ammonia...... oxidizing bacteria and archaea (AOB and AOA) or nitrate-reducing/denitrifying bacteria via their supply of nitrite. Along the Randers Fjord estuary (Denmark), gradients of salinity, nutrients, and organic loading can be observed, and anammox has been detected previously at some sites. The aim of this study...

  16. Aspectos ecológicos da tripanossomíase americana: XIV - Persistência e potencial de domiciliação de populações triatomínicas silvestres em região de intensa atividade agropecuária Ecological aspects of South American tripanosomiasis: XIV - Persistence and domiciliation potential of sylvatic triatominae populations in an intensive agricultural and cattle breeding region

    Directory of Open Access Journals (Sweden)

    Oswaldo Paulo Forattini

    1979-06-01

    Full Text Available São apresentados os resultados de observações sobre populações triatomínicas extradomiciliares em região de intensa atividade agropecuária. Os restos de vegetação primitiva, embora reduzidos a menos de 8,0%, mostraram-se suficientes para manter essas populações. Pelo menos para Triatoma sordida, a destruição progressiva parece favorecer sua sobrevivência, graças à multiplicação de ecótopos preferidos por esse triatomíneo. Tanto essa espécie como Panstrongylus megistus e Rhodnius neglectus mostraram-se aptos à colonização em ecótopos artificiais representados por galinheiros experimentais.The results of observation of sylvatic triatominae population in a region of intensive agricultural and cattle breeding activity are reported. Important environmental changes had occurred in the area, including destruction of the primitive vegetation and intensive use of pesticides. Nevertheless, these modifications apparently did not affect the survival of Triatominae, since they were found in the remaining vegetation. Moreover, this destruction seems to have favored, to some extent, survival of Triatoma sordida by increasing the available ecotopes. This species, as well as Panstrongylus megistus and Rhodnius neglectus, showed enough ecological valence to colonize experimental fowes houses, used as artificial ecotopes.

  17. Levantamento da fauna de Triatominae (Hemiptera: Reduviidae em ambiente domiciliar e infecção natural por Trypanosomatidae no Estado de Mato Grosso do Sul Survey of Triatominae (Hemiptera: Reduviidae fauna in domestic environments and natural infection by Trypanosomatidae in the State of Mato Grosso do Sul

    Directory of Open Access Journals (Sweden)

    Paulo Silva de Almeida

    2008-08-01

    Full Text Available Entre 2000 a 2004, foi realizado levantamento da fauna de Triatominae (Hemiptera: Reduviidae e exame de infecção natural por Trypanosomatidae, no Estado de Mato Grosso do Sul. Um total de 13.671 espécimes foram capturados. Na análise faunística das espécies capturadas, Triatoma sordida foi caracterizada como muito abundante, muito freqüente, constante e dominante. Os índices de infecção natural para Trypanosoma cruzi apresentaram os valores de 3,2% para Panstrongylus geniculatus, 0,6% para Rhodnius neglectus e 0,1% para Triatoma sordida, apesar do Estado de Mato Grosso do Sul apresentar-se livre da transmissão vetorial endêmica.Between 2000 and 2004, a survey of Triatominae fauna (Hemiptera: Reduviidae and examination of natural infection caused by Trypanosomatidae in the State of Mato Grosso do Sul, Brazil, was conducted. A total of 13,671 specimens were collected. Through fauna analysis on the insects that were caught, Triatoma sordida was characterized as very abundant, very frequent, constant and dominant. The rates of natural infection with Trypanosoma cruzi were 3.2% for Panstrongylus geniculatus, 0.6% for Rhodnius neglectus and 0.1% for Triatoma sordida. Nevertheless, the State of Mato Grosso do Sul is free from endemic vector transmission.

  18. Epidemiologia de um caso de doença de Chagas na Ilha do Mosqueiro - Pará

    Directory of Open Access Journals (Sweden)

    Adelson A.A. de Souza

    1988-12-01

    Full Text Available Os autores apresentam os resultados do estudo epidemiológico de um caso autóctone da fase aguda da doença de Chagas na ilha do Mosqueiro, Estado do Pará, aproximadamente 75km da capital, Belém. 0 caso já havia sido objeto de uma publicação anterior. Agora são apresentadas informações epidemiológicas. Nas proximidades da casa do paciente foram capturados em duas palmeiras de Inajá ('Maximilian regi ay e em uma de Mucajá (Acrocomia sclerocarpia 114 triatomíneos: Rhodnius pictipes, R. robustus, Panstrongylus lignarius, P. geniculatus e Microtriatoma trinidadensis, com tripanossomas em 31 deles. Na casa do paciente foram encontrados exemplares de Rhodnius pictipes, infectados com formas metacíclicas do Trypanosoma cruzi. Em 14 marsupiais, capturados na localidade, haviam 3 infectados com organismos semelhantes ao T. cruzi. A eletroforese dos isoenzimas nos tripanossomas isolados do paciente, de R. pictipes e de Didelphis marsupialis os classificou como zimodema 1. Os autores concluem que a doença de Chagas do paciente teve origem silvestre.

  19. Investigations on avoidance of hot cracks during laser welding of austenitic Cr-Ni steels and nickel-based alloys using temperature field tailoring. Final report; Untersuchungen zur Vermeidung von Heissrissen beim Laserstrahlschweissen von austenitischen Cr-Ni-Staehlen und Nickelbasislegierungen mittels Temperaturfeld-Tailoring. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-08-08

    The aim of the project was to transfer the developed method of laser beam welding of heat treated machining steels of temperature field tailoring on hot crack endangered austenitic Cr-Ni steels and nickel-based alloys. With this method, transient thermal stresses adjacent to the weld are produced by an travelling induction heating so that the hot cracking is prevented during welding. As test materials the austenitic Cr-Ni steel with sulfur additive 1.4305, the Cr-Ni steels 1.4404 and 1.4435 and the nickel-based alloy Udimet 720 were selected. As a result of the research it was shown that a hot crack-free laser welding in the investigated materials using at least three different welding and material-technical approaches is possible. [German] Das Ziel des Forschungsvorhabens bestand darin, das fuer das Laserstrahlschweissen verguetbarer Automatenstaehle entwickelte Verfahren des Temperaturfeld-Tailorings auf heissrissgefaehrdete austenitische Cr-Ni-Staehle und Nickelbasislegierungen zu uebertragen. Mit diesem Verfahren werden waehrend des Schweissens transiente thermische Spannungen neben der Schweissnaht durch eine mitlaufende induktive Erwaermung so erzeugt, dass die Heissrissbildung verhindert wird. Als Versuchswerkstoffe wurden der austenitische Cr-Ni-Stahl mit Schwefelzusatz 1.4305, die Cr-Ni-Staehle 1.4404 und 1.4435 sowie die Nickelbasislegierung Udimet 720 ausgewaehlt. Im Ergebnis des Forschungsvorhabens konnte gezeigt werden, dass ein heissrissfreies Laserstrahlschweissen bei den untersuchten Werkstoffen unter Nutzung von mindestens drei verschiedenen schweiss- und werkstofftechnischen Ansaetzen moeglich ist: Erstens koennen mit einem Temperaturfeld-Tailoring bei im Stumpfstoss zu verschweissenden Blechen aus austenitischen Staehlen bis mindestens 6 mm Dicke senkrecht zur Naht und parallel zur Blechoberflaeche wirkende transiente Druckspannungen erzeugt werden, die der Bildung von Mittelrippenrissen oder dazu parallel liegenden Heissrissen entgegenwirken

  20. Epidemiologia de um caso de doença de Chagas na Ilha do Mosqueiro - Pará

    Directory of Open Access Journals (Sweden)

    Adelson A.A. de Souza

    1988-12-01

    Full Text Available Os autores apresentam os resultados do estudo epidemiológico de um caso autóctone da fase aguda da doença de Chagas na ilha do Mosqueiro, Estado do Pará, aproximadamente 75km da capital, Belém. 0 caso já havia sido objeto de uma publicação anterior. Agora são apresentadas informações epidemiológicas. Nas proximidades da casa do paciente foram capturados em duas palmeiras de Inajá ('Maximilian regi ay e em uma de Mucajá (Acrocomia sclerocarpia 114 triatomíneos: Rhodnius pictipes, R. robustus, Panstrongylus lignarius, P. geniculatus e Microtriatoma trinidadensis, com tripanossomas em 31 deles. Na casa do paciente foram encontrados exemplares de Rhodnius pictipes, infectados com formas metacíclicas do Trypanosoma cruzi. Em 14 marsupiais, capturados na localidade, haviam 3 infectados com organismos semelhantes ao T. cruzi. A eletroforese dos isoenzimas nos tripanossomas isolados do paciente, de R. pictipes e de Didelphis marsupialis os classificou como zimodema 1. Os autores concluem que a doença de Chagas do paciente teve origem silvestre.The authors present the results of an epidemiological study relating to a case of acute Chagas' disease acquired in the island of Mosqueiro, State of Para, approximately 75 km from the capital Belem. The patient has been the object of a previous publication but now epidemiological information is reported. Near the house of the patient in two Inaja palm trees (Maximilian regia and one Mucaja palm (Acrocomia sclerocarpia 114 triatomine bugs were captured of the following species: Rhodnius pictipes, R. robustus, Panstrongylus lignarius, P. geniculatus and Microtriatoma trinidadensis. Trypanosomes were found in 31 bugs. In the house of the patient specimens of R. pictipes were captured infected with metacyclic forms óf Trypanosoma cruzi. In 14 marsupials captured in the locality three had infections with cruzi like trypanosomes. Enzyme electrophoresis of the trypanosomes isolated from the patient, R

  1. The importance of the opossum (Didelphis albiventris as a reservoir for Trypanosoma cruzi in Bambuí, Minas Gerais state

    Directory of Open Access Journals (Sweden)

    Alexandre José Fernandes

    1991-03-01

    Full Text Available In a survey realized on the sylvatic and peridomestic environment at Bambuí county, Minas Gerais State, 44 (37.9% out of 116 opossums (Didelphis albiventris captured were found to be naturally infected with Trypanosoma cruzi. One handred and forty three parasite samples were obtanied from 43 infected opossums using simultaneously hemoculture, xenodiagnosis (Triatoma infestans, Panstrongylus megistus and Rhodnius neglectus and examination of anal glands contents. The parasite samples were characterized according to six isoenzyme patterns. All samples, independently of the method of isolation, presented an isoenzyme pattern similar to the standard T. cruzi Z1, showing that either xenodiagnosis or hemoculture can used without selecting parasite subpopulation from naturally infected opossums. Preveous isoenzyme patterns reported for human T.cruzi isolates from same region were completely different. This isoenzyme dissimilarity between sylvatic and domiciliar environments suggests the existence of two independent T. cruzi transmission cycles in Bambuí. The epidemiological implicatinos of these results are discussed.

  2. On the possibility of autochthonous Chagas disease in Roraima, Amazon region, Brazil, 2000-2001 Sobre a possibilidade da ocorrência de doença de Chagas autóctone em Roraima, Amazônia brasileira, 2000-2001

    Directory of Open Access Journals (Sweden)

    José Francisco Luitgards-Moura

    2005-02-01

    Full Text Available Chagas disease has been almost entirely eradicated from the arid zones in Central and Northeastern Brazil where rare or no autochthonous cases have been reported. However, in the last 10 years the disease has increasingly been registered in the Amazon Region. Aiming to investigate the possibility of the occurrence of autochthonous cycle of Chagas disease in Roraima, triatomine collections, vectorial susceptibility studies (this one to be shown elsewhere, parasitological and serological analyses were conducted in three agricultural settlement areas (Rorainópolis, Passarão Project and Ilha Community. Blood-donor candidates were also investigated. This is the first epidemiological survey on Chagas disease conducted in agricultural settlements in Roraima. Triatomine species found were Triatoma maculata, Rhodnius pictipes, Rhodnius robustus and Panstrongylus geniculatus. Trypanosoma cruzi detection analyses included xenodiagnosis, indirect immunofluorescence, indirect hemaglutination, ELISA and kinetoplast PCR amplification. Natural triatomine infection was not found in intestinal contents. Twenty-five adult settlers (1.4% out of 1821, all > 15 year-old, 20 migrants presented anti-T. cruzi antibodies. Two migrant settlers (from Minas Gerais and Maranhão tested positive for more than two serological tests, besides either being positive for xenodiagnosis or PCR. Results show that Chagas disease is not endemic in the areas studied. However, all elements of the transmission cycle are present, demanding for an adequate and continuous vigilance.A doença de Chagas foi quase inteiramente erradicada das zonas áridas do Brasil Central e Nordeste, onde ciclos autóctones de transmissão praticamente inexistem. Contudo, na última década a doença vem sendo registrada na Região Amazônica. Objetivando investigar a possibilidade da ocorrência de ciclos autóctones de transmissão em áreas de colonização agrícola no Estado de Roraima, foram realizadas

  3. Absence of domestic triatomine colonies in an area of the coastal region of Ecuador where Chagas disease is endemic

    Directory of Open Access Journals (Sweden)

    Mario J Grijalva

    2010-08-01

    Full Text Available Rhodnius ecuadoriensis is considered the second most important vector of Chagas disease in Ecuador. It is distributed across six of the 24 provinces and occupies intradomiciliary, peridomiciliary and sylvatic habitats. This study was conducted in six communities within the coastal province of Guayas. Triatomine searches were conducted in domestic and peridomestic habitats and bird nests using manual searches, live-bait traps and sensor boxes. Synantrhopic mammals were captured in the domestic and peridomestic habitats. Household searches (n = 429 and randomly placed sensor boxes (n = 360 produced no live triatomine adults or nymphs. In contrast, eight nymphs were found in two out of six searched Campylorhynchus fasciatus (Troglodytidae nests. Finally, Trypanosoma cruzi DNA was amplified from the blood of 10% of the 115 examined mammals. Environmental changes in land use (intensive rice farming, mosquito control interventions and lack of intradomestic adaptation are suggested among the possible reasons for the lack of domestic triatomine colonies.

  4. Correlação entre a positividade do xenodiagnóstico artificial e a quantidade de sangue e triatomíneos utilizados no exame, em pacientes chagásicos crônicos

    OpenAIRE

    Franco,Yara Bandeira Azevedo; Silva,Ionizete Garcia da; Rassi,Anis; Rocha,Alessandra Carla Rodrigues Galvão; Silva,Heloisa Helena Garcia da; Rassi,Gustavo Gabriel

    2002-01-01

    Estudou-se a correlação entre a positividade do xenodiagnóstico artificial e a quantidade utilizada de sangue e de triatomíneos, em 200 pacientes na fase crônica da doença de Chagas. Colheram-se 10 ou 40ml de sangue através de tubos a vácuo, heparinizados com 20,4UI, sendo realizado com 60 e 360 triatomíneos, respectivamente. Usou-se Dipetalogaster maximus, Triatoma infestans, Triatoma vitticeps e Rhodnius neglectus, nos estádios 1°, 3°, 3° e 4°, respectivamente. A coproscopia dos triatomíneo...

  5. [Geographical distribution and indicators entomologic of sinantropic triatomines captured in the State of Goiás].

    Science.gov (United States)

    de Oliveira, Antônio Wilson Soares; da Silva, Ionizete Garcia

    2007-01-01

    The geographic distribution of triatomines in Goiás and entomological indicators in the home environment are presented: home infestation, home triatomine density and vector infection by Trypanosoma cruzi. The indicators studied were from triatomines captured inside and outside homes in 201 municipalities in the State of Goiás, Brazil, between 2000 and 2003. A total of 249,868 home units were investigated and 51,570 triatomines were captured, and 335 specimens were found to be infected with Trypanosoma cruzi. Infestation outside the home was significantly greater than infestation inside the home for the species Triatoma sordida, followed by Panstrongylus megistus. The contrary was observed with the species Rhodnius neglectus, Panstrongylus geniculatus and Triatoma pseudomaculata (p<0.018). There was no significant difference between infestations inside and outside the home for the species Panstrongylus diasi, Triatoma costalimai and Triatoma williami. Only one specimen of Triatoma infestans was captured in the year 2000.

  6. Enzootic transmission of Trypanosoma cruzi and T. rangeli in the Federal District of Brazil Transmissão enzoótica de Trypanosoma cruzi e T. rangeli no Distrito Federal, Brasil

    Directory of Open Access Journals (Sweden)

    Rodrigo Gurgel-Gonçalves

    2004-04-01

    Full Text Available The Federal District of Brazil (DF lies within the Cerrado biome, where open shrubland (savannas is interspersed with riverside gallery forests and permanent swamps (veredas. Trypanosoma cruzi-infected native triatomines occur in the area, but the enzootic transmission of trypanosomatids remains poorly characterized. A parasitological survey involving sylvatic triatomines (166 Rhodnius neglectus collected from Mauritia flexuosa palms and small mammals (98 marsupials and 70 rodents, totaling 18 species was conducted in 18 sites (mainly gallery forests and veredas of the DF. Parasites were isolated, morphologically identified, and characterized by PCR of nuclear (mini-exon gene and kinetoplast DNA (kDNA. Six R. neglectus, seven Didelphis albiventris and one Akodon cursor were infected by trypanosomes; wild reservoir infection is documented for the first time in the DF. kDNA PCR detected T. cruzi in five R. neglectus and mini-exon gene PCR revealed T. cruzi I in isolates from D. albiventris. Parasites infecting one bug yielded T. rangeli KP1+ kDNA amplicons. In spite of the occurrence of T. cruzi-infected D. albiventris (an important wild and peridomestic reservoir and R. neglectus (a secondary vector displaying synanthropic behavior, a low-risk of human Chagas disease transmission could be expected in the DF, considering the low prevalence infection recorded in this work. The detection of T. rangeli KP1+ associated with R. neglectus in the DF widens the known range of this parasite in Brazil and reinforces the hypothesis of adaptation of T. rangeli populations (KP1+ and KP1- to distinct evolutionary Rhodnius lineages.O Distrito Federal (DF do Brasil está localizado no bioma Cerrado, um complexo de fisionomias savânicas incluindo matas de galeria e campos úmidos permanentes (veredas. Triatomíneos silvestres infectados por Trypanosoma cruzi ocorrem na área, mas a transmissão enzoótica de tripanossomatídeos permanece insuficientemente

  7. Contribuição ao estudo da distribuição geográfica de triatomíneos no estado do Piauí

    Directory of Open Access Journals (Sweden)

    Paulo Zábulon de Figueirêdo

    1975-08-01

    Full Text Available Os autores apresentam a atual distribuição geográfica dos triatomineos no Estado do Piauí. Dos 28 municípios trabalhados em três diferentes regiões naturais, 18 apresentaram capturas positivas, com as seguintes espécies: Triatoma brasiliensis, T. maculata, T. sórdida, Rhodnius pictepes, R. neglectus e Panstrongylus geniculatus. Das espécies citadas, o T. brasiliensis foi a mais freqüente e de maior distribuição. Os autores admitem ser essa espécie a mais importante transmissora da Doença de Chagas, no Estado. Chamam a atenção, ainda, para o papel que as espécies de R. pictepes e R. neglectus possam desempenhar na manutenção do ciclo silvestre do Trypanosoma cruzi, ao lado do P. geniculatus.

  8. Triatominae et Cactaceae : un risque pour la transmission de la Trypanosomose américaine dans le péridomicile (nord-est du Brésil

    Directory of Open Access Journals (Sweden)

    Emperaire L.

    2006-06-01

    Full Text Available Les observations de terrain réalisées dans le nord-est du Brésil ont montré la fréquente association, dans l’espace péridomiciliaire, entre un cactus, le Cereus jamacaru, la présence de nids dans ses branches et celle de Rhodnius neglectus et de Triatoma pseudomaculata, espèces vectrices du parasite Trypanosoma cruzi, agent de la maladie de Chagas. L’analyse des variables architecturales de cette Cactaceae montre que la présence de nids, et donc d’insectes, est inféodée aux pratiques traditionnelles de gestion de ce cactus. Cette étude souligne l’intérêt d’une approche intégrée de l’écologie des Triatominae pour l’identification des variables indicatrices de risque.

  9. Trapping Triatominae in Silvatic Habitats

    Directory of Open Access Journals (Sweden)

    Noireau François

    2002-01-01

    Full Text Available Large-scale trials of a trapping system designed to collect silvatic Triatominae are reported. Live-baited adhesive traps were tested in various ecosystems and different triatomine habitats (arboreal and terrestrial. The trials were always successful, with a rate of positive habitats generally over 20% and reaching 48.4% for palm trees of the Amazon basin. Eleven species of Triatominae belonging to the three genera of public health importance (Triatoma, Rhodnius and Panstrongylus were captured. This trapping system provides an effective way to detect the presence of triatomines in terrestrial and arboreal silvatic habitats and represents a promising tool for ecological studies. Various lines of research are contemplated to improve the performance of this trapping system.

  10. Trypanosoma cruzi I genotypes in different geographic regions and transmission cycles based on a microsatellite motif of the intergenic spacer of spliced leader genes✯

    Science.gov (United States)

    Cura, Carolina I.; Mejía-Jaramillo, Ana M.; Duffy, Tomás; Burgos, Juan M.; Rodriguero, Marcela; Cardinal, Marta V.; Kjos, Sonia; Gurgel-Gonçalves, Rodrigo; Blanchet, Denis; De Pablos, Luis M.; Tomasini, Nicolás; Silva, Alex Da; Russomando, Graciela; Cuba Cuba, Cesar A.; Aznar, Christine; Abate, Teresa; Levin, Mariano J.; Osuna, Antonio; Gürtler, Ricardo E.; Diosque, Patricio; Solari, Aldo; Triana-Chávez, Omar; Schijman, Alejandro G.

    2011-01-01

    The intergenic region of spliced-leader (SL-IR) genes from 105 Trypanosoma cruzi I (Tc I) infected biological samples, culture isolates and stocks from 11 endemic countries, from Argentina to the USA were characterised, allowing identification of 76 genotypes with 54 polymorphic sites from 123 aligned sequences. On the basis of the microsatellite motif proposed by Herrera et al. (2007) to define four haplotypes in Colombia, we could classify these genotypes into four distinct Tc I SL-IR groups, three corresponding to the former haplotypes Ia (11 genotypes), Ib (11 genotypes) and Id (35 genotypes); and one novel group, Ie (19 genotypes). Genotypes harboring the Tc Ic motif were not detected in our study. Tc Ia was associated with domestic cycles in southern and northern South America and sylvatic cycles in Central and North America. Tc Ib was found in all transmission cycles from Colombia. Tc Id was identified in all transmission cycles from Argentina and Colombia, including Chagas cardiomyopathy patients, sylvatic Brazilian samples and human cases from French Guiana, Panama and Venezuela. Tc Ie gathered five samples from domestic Triatoma infestans from northern Argentina, nine samples from wild Mepraia spinolai and Mepraia gajardoi and two chagasic patients from Chile and one from a Bolivian patient with chagasic reactivation. Mixed infections by Tc Ia + Tc Id, Tc Ia + Tc Ie and Tc Id + Tc Ie were detected in vector faeces and isolates from human and vector samples. In addition, Tc Ia and Tc Id were identified in different tissues from a heart transplanted Chagas cardiomyopathy patient with reactivation, denoting histotropism. Trypanosoma cruzi I SL-IR genotypes from parasites infecting Triatoma gerstaeckeri and Didelphis virginiana from USA, T. infestans from Paraguay, Rhodnius nasutus and Rhodnius neglectus from Brazil and M. spinolai and M. gajardoi from Chile are to our knowledge described for the first time. PMID:20670628

  11. Distribuição geográfica e indicadores entomológicos de triatomíneos sinantrópicos capturados no Estado de Goiás Geographical distribution and indicators entomologic of sinantropic triatomines captured in the State of Goiás

    Directory of Open Access Journals (Sweden)

    Antônio Wilson Soares de Oliveira

    2007-04-01

    Full Text Available Apresenta-se a distribuição geográfica de triatomíneos em Goiás e indicadores entomológicos no ambiente domiciliar: infestação domiciliar, densidade triatomínica domiciliar e infecção vetorial pelo Trypanosoma cruzi. Os indicadores estudados foram de triatomíneos capturados no intra e peridomicílio, em 201 municípios, no Estado de Goiás, Brasil, no período entre 2000 e 2003. Foram investigadas 249.868 unidades domiciliares e capturados 51.570 triatomíneos, com 335 espécimes infectados com Trypanosoma cruzi. A infestação peridomiciliar foi significativamente maior do que a intradomiciliar na espécie Triatoma sordida, seguida de Panstrongylus megistus. O inverso ocorreu nas espécies Rhodnius neglectus, Panstrongylus geniculatus e Triatoma pseudomaculata (pThe geographic distribution of triatomines in Goiás and entomological indicators in the home environment are presented: home infestation, home triatomine density and vector infection by Trypanosoma cruzi. The indicators studied were from triatomines captured inside and outside homes in 201 municipalities in the State of Goiás, Brazil, between 2000 and 2003. A total of 249,868 home units were investigated and 51,570 triatomines were captured, and 335 specimens were found to be infected with Trypanosoma cruzi. Infestation outside the home was significantly greater than infestation inside the home for the species Triatoma sordida, followed by Panstrongylus megistus. The contrary was observed with the species Rhodnius neglectus, Panstrongylus geniculatus and Triatoma pseudomaculata (p<0.018. There was no significant difference between infestations inside and outside the home for the species Panstrongylus diasi, Triatoma costalimai and Triatoma williami. Only one specimen of Triatoma infestans was captured in the year 2000.

  12. Cultivation-independent methods reveal differences among bacterial gut microbiota in triatomine vectors of Chagas disease.

    Directory of Open Access Journals (Sweden)

    Fabio Faria da Mota

    Full Text Available BACKGROUND: Chagas disease is a trypanosomiasis whose agent is the protozoan parasite Trypanosoma cruzi, which is transmitted to humans by hematophagous bugs known as triatomines. Even though insecticide treatments allow effective control of these bugs in most Latin American countries where Chagas disease is endemic, the disease still affects a large proportion of the population of South America. The features of the disease in humans have been extensively studied, and the genome of the parasite has been sequenced, but no effective drug is yet available to treat Chagas disease. The digestive tract of the insect vectors in which T. cruzi develops has been much less well investigated than blood from its human hosts and constitutes a dynamic environment with very different conditions. Thus, we investigated the composition of the predominant bacterial species of the microbiota in insect vectors from Rhodnius, Triatoma, Panstrongylus and Dipetalogaster genera. METHODOLOGY/PRINCIPAL FINDINGS: Microbiota of triatomine guts were investigated using cultivation-independent methods, i.e., phylogenetic analysis of 16s rDNA using denaturing gradient gel electrophoresis (DGGE and cloned-based sequencing. The Chao index showed that the diversity of bacterial species in triatomine guts is low, comprising fewer than 20 predominant species, and that these species vary between insect species. The analyses showed that Serratia predominates in Rhodnius, Arsenophonus predominates in Triatoma and Panstrongylus, while Candidatus Rohrkolberia predominates in Dipetalogaster. CONCLUSIONS/SIGNIFICANCE: The microbiota of triatomine guts represents one of the factors that may interfere with T. cruzi transmission and virulence in humans. The knowledge of its composition according to insect species is important for designing measures of biological control for T. cruzi. We found that the predominant species of the bacterial microbiota in triatomines form a group of low

  13. The ecotopes and evolution of triatomine bugs (triatominae and their associated trypanosomes

    Directory of Open Access Journals (Sweden)

    Gaunt Michael

    2000-01-01

    Full Text Available Triatomine bug species such as Microtriatoma trinidadensis, Eratyrus mucronatus, Belminus herreri, Panstrongylus lignarius, and Triatoma tibiamaculata are exquisitely adapted to specialist niches. This suggests a long evolutionary history, as well as the recent dramatic spread a few eclectic, domiciliated triatomine species. Virtually all species of the genus Rhodnius are primarily associated with palms. The genus Panstrongylus is predominantly associated with burrows and tree cavities and the genus Triatoma with terrestrial rocky habitats or rodent burrows. Two major sub-divisions have been defined within the species Trypanosoma cruzi, as T. cruzi 1 (Z1 and T. cruzi 2 (Z2. The affinities of a third group (Z3 are uncertain. Host and habitat associations lead us to propose that T. cruzi 1 (Z1 has evolved in an arboreal, palm tree habitat with the triatomine tribe Rhodniini, in association with the opossum Didelphis. Similarly we propose that T. cruzi (Z2 and Z3 evolved in a terrestrial habitat in burrows and in rocky locations with the triatomine tribe Triatomini, in association with edentates, and/or possibly ground dwelling marsupials. Both sub-divisions of T. cruzi may have been contemporary in South America up to 65 million years ago. Alternatively, T. cruzi 2 (Z2 may have evolved more recently from T. cruzi 1 (Z1 by host transfers into rodents, edentates, and primates. We have constructed a molecular phylogeny of haematophagous vectors, including triatomine bugs, which suggests that faecal transmission of trypanosomes may be the ancestral route. A molecular clock phylogeny suggests that Rhodnius and Triatoma diverged before the arrival, about 40 million years ago, of bats and rodents into South America.

  14. Drivers of house invasion by sylvatic Chagas disease vectors in the Amazon-Cerrado transition: A multi-year, state-wide assessment of municipality-aggregated surveillance data.

    Science.gov (United States)

    Brito, Raíssa N; Gorla, David E; Diotaiuti, Liléia; Gomes, Anália C F; Souza, Rita C M; Abad-Franch, Fernando

    2017-11-01

    Insecticide spraying efficiently controls house infestation by triatomine bugs, the vectors of Trypanosoma cruzi. The strategy, however, is ineffective against sylvatic triatomines, which can transmit Chagas disease by invading (without colonizing) man-made structures. Despite growing awareness of the relevance of these transmission dynamics, the drivers of house invasion by sylvatic triatomines remain poorly understood. About 12,000 sylvatic triatomines were caught during routine surveillance in houses of Tocantins state, Brazil, in 2005-2013. Using negative binomial regression, information-theoretic model evaluation/averaging, and external model validation, we investigated the effects of regional (Amazon/Cerrado), landscape (preservation/disturbance), and climate covariates (temperature, rainfall) on the municipality-aggregated numbers of house-invading Rhodnius pictipes, R. robustus, R. neglectus, and Panstrongylus geniculatus. House invasion by R. pictipes and R. robustus was overall more frequent in the Amazon biome, tended to increase in municipalities with more well-preserved land, and decreased in rainier municipalities. Across species, invasion decreased with higher landscape-disturbance levels and in hotter-day municipalities. Invasion by R. neglectus and P. geniculatus increased somewhat with more land at intermediate disturbance and peaked in average-rainfall municipalities. Temperature effects were more pronounced on P. geniculatus than on Rhodnius spp. We report widespread, frequent house invasion by sylvatic triatomines in the Amazon-Cerrado transition. Our analyses indicate that readily available environmental metrics may help predict the risk of contact between sylvatic triatomines and humans at coarse geographic scales, and hint at specific hypotheses about climate and deforestation effects on those vectors-with some taxon-specific responses and some seemingly general trends. Thus, our focal species appear to be quite sensitive to higher

  15. Cultivation-independent methods reveal differences among bacterial gut microbiota in triatomine vectors of Chagas disease.

    Science.gov (United States)

    da Mota, Fabio Faria; Marinho, Lourena Pinheiro; Moreira, Carlos José de Carvalho; Lima, Marli Maria; Mello, Cícero Brasileiro; Garcia, Eloi Souza; Carels, Nicolas; Azambuja, Patricia

    2012-01-01

    Chagas disease is a trypanosomiasis whose agent is the protozoan parasite Trypanosoma cruzi, which is transmitted to humans by hematophagous bugs known as triatomines. Even though insecticide treatments allow effective control of these bugs in most Latin American countries where Chagas disease is endemic, the disease still affects a large proportion of the population of South America. The features of the disease in humans have been extensively studied, and the genome of the parasite has been sequenced, but no effective drug is yet available to treat Chagas disease. The digestive tract of the insect vectors in which T. cruzi develops has been much less well investigated than blood from its human hosts and constitutes a dynamic environment with very different conditions. Thus, we investigated the composition of the predominant bacterial species of the microbiota in insect vectors from Rhodnius, Triatoma, Panstrongylus and Dipetalogaster genera. Microbiota of triatomine guts were investigated using cultivation-independent methods, i.e., phylogenetic analysis of 16s rDNA using denaturing gradient gel electrophoresis (DGGE) and cloned-based sequencing. The Chao index showed that the diversity of bacterial species in triatomine guts is low, comprising fewer than 20 predominant species, and that these species vary between insect species. The analyses showed that Serratia predominates in Rhodnius, Arsenophonus predominates in Triatoma and Panstrongylus, while Candidatus Rohrkolberia predominates in Dipetalogaster. The microbiota of triatomine guts represents one of the factors that may interfere with T. cruzi transmission and virulence in humans. The knowledge of its composition according to insect species is important for designing measures of biological control for T. cruzi. We found that the predominant species of the bacterial microbiota in triatomines form a group of low complexity whose structure differs according to the vector genus.

  16. Joining of cemented carbides to steel by laser beam welding

    Energy Technology Data Exchange (ETDEWEB)

    Barbatti, C.; Garcia, J.; Pyzalla, A. [Max-Planck-Institut fuer Eisenforschung GmbH, 40237 Duesseldorf (Germany); Liedl, G. [TU Wien, Institut fuer Umform- und Hochleistungslasertechnik (IFLT), 1040 Vienna (Austria)

    2007-11-15

    Welding of dissimilar materials such as steel and cemented carbides (hardmetals, cermets) is particularly challenging e.g. because mismatches in their thermal expansion coefficients and thermal conductivities result in residual stress formation and because of the formation of brittle intermetallic phases. Laser beam welding of cemented carbides to steel appears as an attractive complementary technique to conventional brazing processes due to its high precision, high process speed, low heat input and the option of welding without filler. Here a laser welding process including pre-heat treatment and post-heat treatment was applied successfully to joining as-sintered and nitrided hardmetals and cermets to low alloyed steel. The microstructure and mechanical properties of the welds are investigated by microscopy, X-ray diffraction, microhardness measurements, and bending tests. The results reveal that the three-step laser beam welding process produced crack-free and non-porous joints. Nitridation of the cemented carbides results in a significant reduction of the amount of brittle intermetallic phases. The mechanical properties of the joints are competitive to those of the conventional brazed steel-cemented carbide joints. (Abstract Copyright [2007], Wiley Periodicals, Inc.) [German] Das Schweissen von ungleichartigen Werkstoffen wie z. B. Staehlen mit Hartmetallen und Cermets stellt eine erhebliche Herausforderung dar, u. a. infolge der unterschiedlichen thermischen Ausdehnungskoeffizienten und Waermeleitfaehigkeiten, welche die Bildung von Eigenspannungen zur Folge haben, sowie aufgrund der Bildung sproeder intermetallischer Phasen. Das Laserstrahlschweissen von Hartmetallen/Cermets mit Stahl erscheint als attraktives komplementaeres Verfahren zum ueblicherweise verwendeten Loeten, da es die Herstellung von Verbindungen mit hoeherer Praezision, hoeherer Geschwindigkeit sowie geringerem Waermeeintrag erlaubt und die Verwendung eines Zusatzwerkstoffs nicht notwendig ist

  17. Out of the Shadows

    Science.gov (United States)

    Byers, Nina; Williams, Gary

    2010-12-01

    Foreword Freeman J. Dyson; Introduction Nina Byers; 1. Hertha Aryton 1854-1923 Joan Mason; 2. Margaret Maltby 1860-1944 Peggy Kidwell; 3. Agnes Pockels 1862-1935 Gary A. Williams; 4. Marie Curie 1867-1934 A. Pais; 5. Henrietta Leavitt 1868-1921 Jean L. Turner; 6. Harriet Brooks 1876-1933 C. W. Wong; 7. Lise Meitner 1878-1968 Ruth Lewin Sime; 8. Emmy Noether 1882-1935 Nina Byers; 9. Inge Lehmann 1888-1993 Bruce A. Bolt; 10. Marietta Blau 1894-1970 Leopold Halpern and Maurice M. Shapiro; 11. Hertha Sponer 1895-1968 Helmut Rechenberg; 12. Irene Joliot-Curie 1897-1956 Hélène Langevin-Joliot and Pierre Radvanyi; 13. Katherine Burr Blodgett 1898-1979 Gary A. Williams; 14. Cecilia Payne Gaposchkin 1900-1979 Vera C. Rubin; 15. Mary Cartwright 1900-1998 Freeman J. Dyson; 16. Bertha Jeffreys 1903-1999 Ruth M. Williams; 17. Kathleen Yardley Lonsdale1903-1971 Judith Milledge; 18. Maria Goeppert Mayer 1906-1972 Steven A. Moszkowski; 19. Helen Megaw 1907-2002 A. Michael Glazer and Christine Kelsey; 20. Yvette Cauchois 1908-1999 Christiane Bonnelle; 21. Marguerite Perey 1909-1975 Jean-Pierre Adloff and George B. Kauffman; 22. Dorothy Crowfoot Hodgkin 1910-1994 Jenny P. Glusker; 23. Gertrude Scharff Goldhaber 1911-1998 Alfred Scharff Goldhaber; 24. Chien Shiung Wu 1912-1997 Noemie Bencze-Koller; 25. Margaret E. Burbidge 1919 Virginia Trimble; 26. Phyllis Freier 1921-1992 Cecil J. Waddington; 27. Rosalyn S. Yalow 1921 M. S. Dresselhaus and F. A. Stahl; 28. Esther Conwell 1922 Lewis Rothberg; 29. Cecile Dewitt-Morette 1922 Bryce DeWitt; 30. Yvonne Choquet-Bruhat 1923 James W. York Jr.; 31. Vera Rubin 1928 Robert J. Rubin; 32. Mildred S. Dresselhaus 1930 G. Dresselhaus and F. A. Stahl; 33. Myriam Sarachik 1933 Jonathan R. Friedman; 34. Juliet Lee-Franzini 1933 Paolo Franzini; 35. Helen T. Edwards 1936 John Peoples; 36. Mary K. Gaillard 1939 Andreszej Buras; 37. Renata Kallosh 1943 Andrei Linde and Michael Gutperle; 38. Jocelyn Bell Burnell 1943 Ferdinand V. Coroniti and Gary A

  18. Efficacy of melody-based aphasia therapy may strongly depend on rhythm and conversational speech formulas

    Directory of Open Access Journals (Sweden)

    Benjamin Stahl

    2014-04-01

    Full Text Available Left-hemisphere stroke patients suffering from language and speech disorders are often able to sing entire pieces of text fluently. This finding has inspired a number of melody-based rehabilitation programs – most notable among them a treatment known as Melodic Intonation Therapy – as well as two fundamental research questions. When the experimental design focuses on one point in time (cross section, one may determine whether or not singing has an immediate effect on syllable production in patients with language and speech disorders. When the design focuses on changes over several points in time (longitudinal section, one may gain insight as to whether or not singing has a long-term effect on language and speech recovery. The current work addresses both of these questions with two separate experiments that investigate the interplay of melody, rhythm and lyric type in 32 patients with non-fluent aphasia and apraxia of speech (Stahl et al., 2011; Stahl et al., 2013. Taken together, the experiments deliver three main results. First, singing and rhythmic pacing proved to be equally effective in facilitating immediate syllable production and long-term language and speech recovery. Controlling for various influences such as prosody, syllable duration and phonetic complexity, the data did not reveal any advantage of singing over rhythmic speech. This result was independent of lesion size and lesion location in the patients. Second, patients with extensive left-sided basal ganglia lesions produced more correct syllables when their speech was paced by rhythmic drumbeats. This observation is consistent with the idea that regular auditory cues may partially compensate for corticostriatal damage and thereby improve speech-motor planning (Grahn & Watson, 2013. Third, conversational speech formulas and well-known song lyrics yielded higher rates of correct syllable production than novel word sequences – whether patients were singing or speaking

  19. On-line measurement of mechanical, optical properties and roughness parameters

    Directory of Open Access Journals (Sweden)

    Hartman, H.

    2005-12-01

    Full Text Available On-line measurements become a central importance for the control of production line output. The target is to replace traditional single local destructive quality checks by a continuous survey of the product properties. Other traditional like pyrometric temperature measurements suffer of well-known but non-soluble weakness points. New methods need the unambiguous correlation with the results of traditional testing to be representative for valid proof standards.EKO Stahl GmbH introduces several methods of on-line measurements focused actually on temperature measurement means of FTIR-Spectrometer, prediction of the mechanical properties of steel strips using the information of residual magnetization after a magnetization pulse and optical roughness measurements. The correlation between the results of the new methods and the classical proof processes has been established in a satisfactory manner.

    Las medidas on line van tomando una importancia central para el control de la calidad de la producción . El objetivo es reemplazar las pruebas destructivas puntuales tradicionales por un control continuo de las características del producto. Otros métodos tradicionales, como la medida de la temperatura con pirómetros, adolecen de conocidos pero insolubles puntos débiles. Los nuevos métodos necesitan la correlación inequívoca con los resultados de los métodos corrientes clásicos para obtener la autoridad de un estándar de prueba. La EKO Stahl GmbH ha introducido varios métodos de medidas on line y actualmente concentrados en la medida de la temperatura con espectrómetro FTIR, predicción de las características mecánicas usando la información del magnetismo residual, a partir de un impulso magnético inicial así como la medida óptica de la rugosidad. La correlación entre los resultados de los nuevos métodos y los métodos clásicos ha quedado establecida de manera satisfactoria.

  20. Living with the label "disability": personal narrative as a resource for responsive and informed practice in biomedicine and bioethics.

    Science.gov (United States)

    Bishop, Jeffery; Sunderland, Naomi

    2013-01-01

    What is it like to live with the label "Disability?" NIB editorial staff and narrative symposium editors, Jeffery Bishop and Naomi Sunderland developed a call for stories, which was sent to several list serves, shared with the 1000 Voices Project community and posted on Narrative Inquiry in Bioethics' website. The request for personal stories from people who identify with the label "disabled" asked them to: consider how the label "disability" interacts with other aspects of their life in health care settings; does the term "disability" reflect their actual embodied experiences of impairment or does it fail to do justice to their particular experience of impairment; describe the kind of experiences that are possible because of the impairment(s); discuss how the label has affected their "authentic voice"; and many other concepts about what effects the label has on their lives. These authors share deeply personal experiences that will help readers understand their world, challenges, and joys. Thirteen stories are found in the print version of the journal and an additional five supplemental stories are published online only through Project MUSE. The stories are complemented by four commentary articles by Elizabeth R. Schiltz; Lorna Hallahan; Nicole Matthews, Kathleen Ellem, and Lesley Chenoweth; and Jeffery Bishop, Rachelle Barina, and Devan Stahl. These scholars come from the disciplines of law, social work, media studies, medicine, and bioethics from Australia and the United States. Together, the symposium's storytellers and commentators offer striking and informative insights into the everydayness of living with disabilities.

  1. KOMPOSISI KIMIA MINYAK ATSIRI BUAH SIRIH HIJAU (PIPER BETLE L, KEMUKUS (PIPER CUBEBA L DAN CABE JAWA (PIPER RETROFRACTUM VAHL

    Directory of Open Access Journals (Sweden)

    M. Widyo Wartono

    2014-05-01

    Full Text Available Tumbuhan genus Piper mempunyai kandungan minyak atsiri hampir disemua bagiannya, namun komposisi kimianya belum semua dilaporkan. Pada laporan ini kami melakukan isolasi dan identifikasi senyawa kimia minyak atsiri pada bagian buah tumbuhan Piper. Isolasi minyak atsiri buah Piper dilakukan dengan destilasi air menggunakan destilasi Stahl dan analisis komposisi kimia dengan kromatografi gas-spektroskopi masa (GC-MS. Kandungan minyak atsiri buah sirih hijau (Piper betle 1,4% (v/b, cabe jawa (Piper retrofractum 1% (v/b, dan buah kemukus (Piper cubeba 1,7% (v/b. Hasil analisis GC-MS menunjukan kandungan utama minyak atsiri adalah senyawa golongan monoterpen, seskuiterpen dan fenil propanoid. Kandungan utama minyak atsiri buah sirih hijau (P. betle adalah eugenol (12,36%, isokaryofillena (9,55% dan β-selinena (8,09%, sedangkan komponen utama buah cabe jawa (Piper retrofractum adalah isokaryofilen (8,88%, β-bisabolen (7,01% dan zingiberen (6,32%, dan minyak atsiri buah kemukus (Piper cubeba adalah spathulanol (27,05%, sativen (8,73% dan germakren D (7,50%.

  2. High-performance GFRP materials with glass fibre prepregs; Hochleistungs-Faserverbundwerkstoffe aus UD-Gelegeprepregs

    Energy Technology Data Exchange (ETDEWEB)

    Prause, J.P. [Schichtstoff-Technik, Arnsberg (Germany); Schroeder, K.F. [Wissenschaftliche Verlagsanstalt, Mettmann (Germany)

    1999-07-01

    The US 3M Company is the producer of the 'Scotchply' glass fibre prepreg which results in materials that can withstand higher dynamic loads than conventional glass fibre reinforced plastics. The new materials are used, e.g., for leaf spring construction. The fatigue characteristics of GFRP leaf springs were discussed at the DGM 'Verbundwerkstoffe und Werkstoffverbunde' conference at Kaiserslauter in September 1997. This contribution presents tools for the engineer for calculation of leaf springs in consideration of the expected loads. [German] Bereits frueher konnte nachgewiesen werden, dass mit Glasgarngelegen verstaerkte Kunststoffe dynamisch hoeher beansprucht werden koennen als gleichartige Konstruktionen mit Glasgewebeverstaerkung. Dieser Vorteil wird in der industriellen Praxis genutzt, um den breiten Einsatzbereich von Blattfedern aus Stahl durch solche aus Faserverbundwerkstoffen zu erweitern. Mit Glasfasern verstaerkte Kunststoffe (GFK) sind seit Jahren Stand der Technik. Die Verarbeitung als Gelegeprepreg hat sich oekonomisch und oekologisch als eine guenstige Technologie bewaehrt. Die Prepregs werden im Wickelverfahren in die endgueltige Form gebracht oder zu Platten verpresst, aus denen die gewuenschten Werkstuecke mechanisch herausgearbeitet werden. Eine ideale Ausnutzung aller in UD-Gelegen vorgegebenen Eigenschaften ist die Form der Blattfeder. Werkstoff und Geometrie koennen optimal an die Belastung angepasst werden. Ueber die Ermuedungsfestigkeit von GFK-Blattfedern wurde waehrend der Vortragstagung der DGM 'Verbundwerkstoffe und Werkstoffverbunde' im September 1997 in Kaiserslautern eingehend berichtet. Mit dieser Veroeffentlichung soll dem Ingenieur eine Hilfe gegeben werden, solche Blattfedern entsprechend der spaeteren Beanspruchung zu berechnen. (orig.)

  3. Preemptive Architecture: Explosive Art and Future Architectures in Cursed Urban Zones

    Directory of Open Access Journals (Sweden)

    Stahl Stenslie

    2017-04-01

    Full Text Available This article describes the art and architectural research project Preemptive Architecture that uses artistic strategies and approaches to create bomb-ready architectural structures that act as instruments for the undoing of violence in war. Increasing environmental usability through destruction represents an inverse strategy that reverses common thinking patterns about warfare, art and architecture. Building structures predestined for a construc­tive destruction becomes a creative act. One of the main motivations behind this paper is to challenge and expand the material thinking as well as the socio-political conditions related to artistic, architectural and design based practices.   Article received: December 12, 2016; Article accepted: January 10, 2017; Published online: April 20, 2017 Original scholarly paper How to cite this article: Stenslie, Stahl, and Magne Wiggen. "Preemptive Architecture: Explosive Art and Future Architectures in Cursed Urban Zones." AM Journal of Art and Media Studies 12 (2017: 29-39. doi: 10.25038/am.v0i12.165

  4. Development of the Thyssen hot briquetting process and its industrial application

    Energy Technology Data Exchange (ETDEWEB)

    Hoeffken, E.; Pflipsen, H.D.; Seidelmann, L.; Auth, R.

    1988-07-18

    At Thyssen Stahl AG the converter waste gases of the basic oxygen steelmaking plant Bruckhausen are dedusted according to a new method , the CO included in the waste gas being recovered and used as fuel gas. The dry dusts produced in this process are dumped despite their high iron content. Considerations aimed at recovering this residues have led to the development of a hot briquetting process for converter dusts. Preliminary tests were followedby the construction of a pilot plant with a briqueting capacity of 2 to 3 t/h. As a result of the successful trials, a large-size plant for a throughput rate of 12 t/h was commissioned at mid-1987, which allows to briquet all the dusts produced in the steel plant. About 30000 t briquettes, which are charged as cooling ore and scrap in the steel plant, have been produced so far. In view of the high iron content of 60 to 70% and of the elimination of dumping costs, the process can be operated economically. The recycling of the dust has contributed, moreover, to the relief of the dumping ground and to environmental protection.

  5. Conference on renewable energies integration to power grids

    International Nuclear Information System (INIS)

    Laffaille, Didier; Bischoff, Torsten; Merkel, Marcus; Rohrig, Kurt; Glatigny, Alain; Quitmann, Eckard; Lehec, Guillaume; Teirlynck, Thierry; Stahl, Oliver

    2014-01-01

    The French-German office for Renewable energies (OFAEnR) organised a conference on renewable energies integration to power grids. In the framework of this French-German exchange of experience, more than 150 participants exchanged views on the perspectives and possible solutions of this integration in order to warrant the security of supplies and the grid stability in a context of increasing injection and decentralization of renewable power sources. This document brings together the available presentations (slides) made during this event: 1 - French distribution grids - Overview and perspectives (Didier Laffaille); 2 - Distribution Grids in Germany - Overview and Perspective (Torsten Bischoff); 3 - Integration of renewable energies into distribution grids - a case example from Germany (Marcus Merkel); 4 - Regeneratives Kombikraftwerk Deutschland: System Services with 100 % Renewable energies (Kurt Rohrig); 5 - Overview of the different grid instrumentation-control and automation tools (Alain Glatigny); 6 - Which Ancillary Services needs the Power System? The contribution from Wind Power Plants (Eckard Quitmann); 7 - The Flexibility Aggregator - the example of the GreenLys Project (Guillaume Lehec); 8 - Energy Pool - Providing flexibility to the electric system. Consumption cut-off solutions in France (Thierry Teirlynck); 9 - Demand Response experiences from Germany (Oliver Stahl)

  6. Insect resistance to Nilaparvata lugens and Cnaphalocrocis medinalis in transgenic indica rice and the inheritance of gna+sbti transgenes.

    Science.gov (United States)

    Li, Guiying; Xu, Xinping; Xing, Hengtai; Zhu, Huachen; Fan, Qin

    2005-04-01

    Molecular genetic analysis and insect bioassay of transgenic indica rice 'Zhuxian B' plants carrying snowdrop lectin gene (gna) and soybean trypsin inhibitor gene (sbti) were investigated in detail. PCR, 'dot' blot and PCR-Southern blot analysis showed that both transgenes had been incorporated into the rice genome and transmitted up to R3 progeny in most lines tested. Some transgenic lines exhibited Mendelian segregation, but the other showed either 1:1 (positive: negative for the transgenes) or other aberrant segregation patterns. The segregation patterns of gna gene crossed between R2 and R3 progeny. In half of transgenic R3 lines, gna and sbti transgenes co-segregated. Two independent homozygous lines expressing double transgenes were identified in R3 progeny. Southern blot analysis demonstrated that the copy numbers of integrated gna and sbti transgenes varied from one to ten in different lines. Insect bioassay data showed that most transgenic plants had better resistance to both Nilaparvata lugens (Stahl) and Cnaphalocrocis medinalis (Guenee) than wild-type plants. The insect resistance of transgenic lines increased with the increase in transgene positive ratio in most of the transgenic lines. In all, we obtained nine lines of R3 transgenic plants, including one pure line, which had better resistance to both N lugens and C medinalis than wild-type plants. Copyright 2005 Society of Chemical Industry.

  7. Mango resistance to fruit flies. II - resistance of the alfa cultivar

    Energy Technology Data Exchange (ETDEWEB)

    Rossetto, C.J.; Bortoletto, N., E-mail: rossetto@iac.sp.gov.b [Agencia Paulista de Tecnologia dos Agronegocios (APTA), Votuporanga, SP (Brazil). Polo Regional do Noroeste Paulista; Walder, J.M.M.; Mastrangelo, T. de A., E-mail: jmwalder@cena.usp.b [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Carvalho, C.R.L.; Castro, J.V. de, E-mail: climonta@iac.sp.gov.b, E-mail: josalba@iac.sp.gov.b [Instituto Agronomico de Campinas, SP (Brazil); Pinto, A.C. de Q. [EMBRAPA, Brasilia, DF (Brazil); Cortelazzo, A.L., E-mail: angelo@unicamp.b [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Biologia

    2006-07-01

    The percentage of infested mango fruits of five selected mango varieties was evaluated during three years under field conditions. Three varieties with field resistance to fruit flies had less then 10% of fruits infested. Tommy Atkins, the susceptible commercial check, had 42,9% and the susceptible check had 98.9 % of infested fruits. The three field resistant varieties plus the susceptible commercial check, Tommy Atkins, were further tested in laboratory, under caged conditions, with artificial infestation of Anastrepha obliqua. The attempts of oviposition and the number of pupae developed from each fruit were evaluated. Under caged conditions, the cultivar Alfa maintained its field resistance and Espada Stahl and IAC 111 lost the field resistance and were as susceptible as Tommy Atkins. The attempts of oviposition were positively and highly correlated with the number of pupae developed in the fruits. Non preference for oviposition was confirmed as the main mechanism of resistance of mango fruits to fruit flies. In the absence of a more susceptible variety (no choice test) the cultivar Alfa has kept the resistance (author)

  8. Air and the origin of the experimental plant physiology.

    Science.gov (United States)

    Pennazio, Sergio

    2005-01-01

    It is well known that oxygen and carbon dioxide are two chemicals which enter the plant metabolism as nutrients. The bases of this nowadays obvious statement were placed in the 18th century by means of the works of ingenious naturalists such as Robert Boyle, Stephen Hales, Joseph Priestley, Jam Ingenhousz, Lazzaro Spallanzani and Theodore De Saussure. Till the end of the 17th century, the atmospheric air was considered as an ineffable spirit, the function of which was of physical nature. Boyle was the first naturalist to admit the possibility that respiration were an exchange of vapours occurring in the blood. Stephen Hales realised that air could be fixed by plants under the influence of solar light. Priestley showed that plants could regenerate the bad air making it breathable. Ingenhousz demonstrated that the green parts of plants performed the complete purification of air only under the influence of the light. Spallanzani discovered that plants respire and guessed that the good air (oxygen) originated from the fixed air (carbon dioxide). Finally, Theodore De Saussure showed that plants were able to adsorb carbon dioxide and to release oxygen in a proportional air. All these discoveries benefited of the results coming from investigations of scholars of the so-called "pneumatic chemistry" (Boyle himself, George Ernst Stahl, Joseph Black, Priestley himself, and many more others. But among all the eminent scientists above mentioned stands out the genius of Antoine Laurent Lavoisier, who revolutionised the chemistry of the 18th century ferrying it towards the modern chemistry.

  9. Influence of Z-phase on Long-term Creep Stability of Martensitic 9 to 12 % Cr Steels

    DEFF Research Database (Denmark)

    Danielsen, Hilmar Kjartansson; Hald, John

    2009-01-01

    Die langfristige Kriechstabilität der neuesten Generation martensitischer 9 bis 12 % kriechfester Stähle basiert auf dem bekannten Grade 91, d. h. auf der Stärkung durch die feinen MNNitride (V und Nb). Langzeit-Hochtemperaturtests zeigen den Ersatz der MN-Nitride durch die thermodynamisch...... stabileren Z-Phasen (Cr(V,Nb)N) mit einem Verlust an Kriechfestigkeit. Cr-Gehalte >10,5 % beschleunigen die Ausscheidung der Z-Phasen. Dies beschränkte Bemühungen, einen martensitischen, kriechfesten Stahl mit hohem Cr-Gehalt zum Schutz vor Oxidation zu entwickeln. 9-%-Cr-Stähle werden offensichtlich nicht...... durch die Z-Phase negativ beeinflusst. Die Untersuchung der Z-Phasen-Ausscheidung hat zur Entwicklung eines 12-%-Cr-martensitischen Versuchsstahls geführt, dessen Kriechfestigkeit durch die Z-Phase gewährleistet wird. Derartige Stähle erlauben die ombination hoher Festigkeit bei gleichzeitig guter...

  10. Isothermal steam oxidation of the ferritic 11% Cr steel (DIN No. 1.4914) at 900 to 13000C

    International Nuclear Information System (INIS)

    Zurek, Z.

    1982-11-01

    The steam oxidation of ferritic 11% Cr steel tube and sheet samples at 900 to 1300 0 C has been studied gravimetrically, metallographically, by X-ray diffraction and in detail by electron probe microanalysis. The reaction rate could be described by parabolic kinetics of mass increase. During the oxidation a three-layer scale was formed on the surface. The inner layer was composed of iron-chromium spinel, the intermediate layer consisted of a mixture wustite and magnetite, the very thin outer layer was composed of magnetite. Within the inner scale layer small metallic particles enriched of nickel could be observed. The scale cohesion was generally poor for tube as well as for sheet material and was improving with oxidation time and temperature. After oxidation Pt-markers indicated the growth of inner and outer layer in relation to the initial metal surface. The sheet material specimens exposed at 1000-1100 0 C had blisters on their surfaces. A swelling of about 12-15% was measured for the oxidized tubing. Isotherme Dampf-Oxidation des ferritischen 11% Cr-Stahls (Werkstoff Nr. 1.4914) bei 900 - 1300 0 C. (orig.) [de

  11. “Invading Your Hearts and Minds”: Call of Duty®and the (ReWriting of Militarism in U.S. Digital Games and Popular Culture

    Directory of Open Access Journals (Sweden)

    Frédérick Gagnon 1

    2010-11-01

    Full Text Available The goal of this article is to discuss how digital war games such as the Call of Duty series elicit consent for the U.S. military, militarism and the wars waged by the U.S. and its allies abroad. Building bridges between the humanities approach to Game Studies, American Studies, International Relations and Critical Geopolitics, we start from the assumption that digital games are more than “kid’s games”; they are sophisticated vehicles inhabiting and disseminating specific ideologies (Leonard 2004. Accordingly, our goal is to conduct a content analysis (Sisler 2008 of Call of Duty 4: Modern Warfare and Call of Duty: Modern Warfare 2 to show how these games contain images and narratives that (1 resonate with and reinforce a tabloid imaginary of post-9/11 geopolitics (Debrix 2008; (2 glorify military power and elicit consent for the idea that state violence and wars are inevitable; and (3 encourage our myopia by depicting a sanitized vision of war and downplaying the negative consequences of state violence (Stahl 2006. The conclusion invites players to think about ways to criticize the way games like Call of Duty employ and deploy values that (rewrite the militarist mindset that has often pervaded the post-9/11 U.S. national security debate.

  12. First signal from a broadband cryogenic preamplifier cooled by circulating liquid nitrogen in a 7 T Fourier transform ion cyclotron resonance mass spectrometer.

    Science.gov (United States)

    Choi, Myoung Choul; Lee, Jeong Min; Lee, Se Gyu; Choi, Sang Hwan; Choi, Yeon Suk; Lee, Kyung Jae; Kim, SeungYong; Kim, Hyun Sik; Stahl, Stefan

    2012-12-18

    Despite the outstanding performance of Fourier transform ion cyclotron/mass spectrometry (FTICR/MS), the complexity of the cellular proteome or natural compounds presents considerable challenges. Sensitivity is a key performance parameter of a FTICR mass spectrometer. By improving this parameter, the dynamic range of the instrument can be increased to improve the detection signal of low-abundance compounds or fragment ion peaks. In order to improve sensitivity, a cryogenic detection system was developed by the KBSI (Korean Basic Science Institute) in collaboration with Stahl-Electronics (Mettenheim, Germany). A simple, efficient liquid circulation cooling system was designed and a cryogenic preamplifier implemented inside a FTICR mass spectrometer. This cooling system circulates a cryoliquid from a Dewar to the "liquid circulation unit" through a CF flange to cool a copper block and a cryopreamplifier; the cooling medium is subsequently exhausted into the air. The cryopreamplifier can be operated over a very wide temperature range, from room temperature to low temperature environments (4.2 K). First, ion signals detected by the cryopreamplifier using a circulating liquid nitrogen cooling system were observed and showed a signal-to-noise ratio (S/N) about 130% better than that obtained at room temperature.

  13. Nitrogen transport during plasma-enhanced case nitriding of stainless steels - the effects of the passivating oxide layer; Stickstofftransport waehrend der plasmagestuetzten Randaufstickung nichtrostender Staehle - der Einfluss der passivierenden Oxidschicht

    Energy Technology Data Exchange (ETDEWEB)

    Parascandola, S.; Kruse, O.; Richter, E. [Forschungszentrum Rossendorf e.V. (FZR), Dresden (Germany). Inst. fuer Ionenstrahlphysik und Materialforschung; Moeller, W.

    1998-12-31

    Plasma-enhanced case nitriding at moderate temperatures is a promising technique for surface treatment of components made of stainless steels. In-situ ERD permits time-resolved and depth-dependent elemental analysis during the case nitriding process. This offers possibilities for process characterisation which are only briefly discussed in the paper. The oxide layer at the surface of the steel is a barrier to nitrogen input. In order to achieve fast nitrogen diffusion into the material, the oxide layer has to be largely removed in the low-energy ion implantation process. The observed equilibrium between diffusion and re-absorption is in good agreement with calculated as well as empirical results. (orig./CB) [Deutsch] Die plasmagestuetzte Randaufstickung bei moderaten Temperaturen ist eine erfolgversprechende Technologie zur Oberflaechenveredelung von Bauteilen aus nichtrostendem Stahl. Die Analytik mit in-situ ERD erlaubt zeit- und tiefenaufgeloeste Elementanalyse waehrend des Aufstickungsprozesses. Dadurch ergeben sich Moeglichkeiten der Prozesscharakterisierung, die hier nur angedeutet werden konnten. Die Oxidschicht an der Oberflaeche der nichtrostenden Staehle stellt eine Barriere fuer den Stickstoffeintrag dar. Fuer schnelle Stickstoffdiffusion muss die Oxidschicht bei der Niederenergie-Ionenimplantation weitgehend abgebaut werden. Das beobachtete Gleichgewicht zwischen Zerstaeubung und Wiederbelegung stimmt gut mit Simulationsrechnungen bzw. empirischen Werten ueberein. (orig.)

  14. Low temperature X-ray imaging of magnetic flux patterns in high temperature superconductors

    Science.gov (United States)

    Stahl, Claudia; Ruoß, Stephen; Weigand, Markus; Bechtel, Michael; Schütz, Gisela; Albrecht, Joachim

    2015-05-01

    We present X-ray magnetic circular dichroism (XMCD) microscopy results obtained at liquid nitrogen temperatures on the high-Tc superconductor YBCO (YBa2Cu3O7-δ). The magnetic flux distribution arising from electric currents in the superconductor is detected and visualized using soft-magnetic Co40Fe40B20 (CoFeB) as sensor layer and XMCD as contrast mechanism. It has been shown that the XMCD contrast in the sensor layer directly corresponds to magnetic flux distribution of the superconductor and hence can be used to image magnetic structures in superconductors [Stahl et al., Phys. Rev. B 90, 104515 (2014)]. The existing scanning UHV X-ray microscopy setup MAXYMUS at the synchrotron BESSY II in Berlin has been upgraded for that purpose: we use a nitrogen based MMR Micro Miniature Joule-Thompson Cryostat with temperature range from 75 K to 580 K. The capability of the method is demonstrated on two different superconducting samples, an optimally doped thin film and a melt-textured block.

  15. Formability Characterization of a New Generation High Strength Steels

    Energy Technology Data Exchange (ETDEWEB)

    Sriram Sadagopan; Dennis Urban; Chris Wong; Mai Huang; Benda Yan

    2003-05-16

    Advanced high strength steels (AHSS) are being progressively explored by the automotive industry all around the world for cost-effective solutions to accomplish vehicle lightweighting, improve fuel economy, and consequently reduce greenhouse emissions. Because of their inherent high strength, attractive crash energy management properties, and good formability, the effective use of AHSS such as Duel Phase and TRIP (Transformation Induced Plasticity) steels, will significantly contribute to vehicle lightweighting and fuel economy. To further the application of these steels in automotive body and structural parts, a good knowledge and experience base must be developed regarding the press formability of these materials. This project provides data on relevant intrinsic mechanical behavior, splitting limits, and springback behavior of several lots of mild steel, conventional high strength steel (HSS), advanced high strength steel (AHSS) and ultra-high strength steel (UHSS), supplied by the member companies of the Automotive Applications Committee (AAC) of the American Iron and Steel Institute (AISI). Two lots of TRIP600, which were supplied by ThyssenKrupp Stahl, were also included in the study. Since sheet metal forming encompasses a very diverse range of forming processes and deformation modes, a number of simulative tests were used to characterize the forming behavior of these steel grades. In general, it was found that formability, as determined by the different tests, decreased with increased tensile strength. Consistant with previous findings, the formability of TRIP600 was found to be exceptionally good for its tensile strength.

  16. Earthworms and their Nephridial Symbionts: Co-diversification and Maintenance of the Symbiosis

    DEFF Research Database (Denmark)

    Lund, Marie Braad; Holmstrup, Martin; Davidson, Seana K.

    Earthworms harbor in their nephridia (excretory organs) symbiotic bacteria which densely colonize a specific part of the nephridia, called the ampulla [1]. The symbiosis is species-specific and the symbionts form their own monophyletic genus Verminephrobacter (β-proteobacteria) [2] and are vertic......,J. 1926. Z Morph Ökol Tiere, 6(3):588-624. [2] Schramm,A. et al. 2003. Environ Microbiol 5(9):804-809. [3] Davidson,S.K. & Stahl,D.A. 2006. Appl Environ Microbiol 72(1):769-775. [4] Pandazis,G. 1931. Zentralbl Bakteriol 120:440-453.......Earthworms harbor in their nephridia (excretory organs) symbiotic bacteria which densely colonize a specific part of the nephridia, called the ampulla [1]. The symbiosis is species-specific and the symbionts form their own monophyletic genus Verminephrobacter (β-proteobacteria) [2...... showed no significant differences in growth rate and fecundity between symbiotic and aposymbiotic worms. Thus the symbionts do not appear to have an effect on worm fitness, under growth conditions tested. The underlying functional and maintaining mechanisms of this symbiosis remain a conundrum. [1] Knop...

  17. Chemistry in Teaching The Moral of the Phlogiston Theory

    Directory of Open Access Journals (Sweden)

    N. Raos

    2015-05-01

    Full Text Available The phlogiston theory, proposed in 1697 by German physician Georg Ernst Stahl (1659 – 1734, was the first scientific theory of combustion. However, it was abandoned by the end of the 18th century after the “Lavoisier revolution”, primarily because it was unable to explain the mass change during chemical reactions. In spite of this, there are modern revitalizations of the theory, claiming that phlogiston could be identified with the electron or even with Gibbs energy. Discussion about such interpretations would be stimulative for the better understanding of the differences between chemical reactions and chemical processes, oxidation and oxygenation, and especially for better understanding the nature of scientific theories. In my view, it is necessary to regard theories in their historical context; the resemblance of an old theory to a new one cannot be the criterion of its validity, much more important is the influence of the former theory on the development of science, especially in the establishment of new concepts.

  18. Investigations on passive containment cooling; Untersuchungen zur passiven Containmentkuehlung

    Energy Technology Data Exchange (ETDEWEB)

    Knebel, J.U.; Cheng, X.; Neitzel, H.J.; Erbacher, F.J. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer Angewandte Thermo- und Fluiddynamik; Hofmann, F. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Projekt Nukleare Sicherheitsforschung

    1997-12-31

    The composite containment design for advanced LWRs that has been examined under the PASCO project is a promising design concept for purely passive decay heat removal after a severe accident. The passive cooling processes applied are natural convection and radiative heat transfer. Heat transfer through the latter process removes at an emission coefficient of 0.9 about 50% of the total heat removed via the steel containment, and thus is an essential factor. The heat transferring surfaces must have a high emission coefficient. The sump cooling concept examined under the SUCO project achieves a steady, natural convection-driven flow from the heat source to the heat sink. (orig./CB) [Deutsch] Das im PASCO Programm untersuchte Verbundcontainment fuer zukuenftige Leichtwasserreaktoren ist ein erfolgversprechendes rein passives System zur Nachwaermeabfuhr nach einem schweren Stoerfall. Die passiven Mechanismen der Waermeuebertragung sind Naturkonvektion und Waermestrahlung. Die durch Waermestrahlung uebertragene Waerme betraegt fuer einen Emissionskoeffizienten von 0.9 etwa 50% der insgesamt ueber das Stahl-Containment abgefuehrten Waerme und ist somit von entscheidender Bedeutung fuer die Nachwaermeabfuhr. Fuer die waermeuebertragenden Oberflaechen ist ein hoher Emissionkoeffizient erforderlich. Das im SUCO Programm untersuchte Sumpfkuehlkonzept realisiert eine stabile Naturkonvektionsstroemung zwischen Waermequelle und Waermesenke. (orig./DG)

  19. Mango resistance to fruit flies. II - resistance of the alfa cultivar

    International Nuclear Information System (INIS)

    Rossetto, C.J.; Bortoletto, N.; Carvalho, C.R.L.; Castro, J.V. de; Pinto, A.C. de Q.; Cortelazzo, A.L.

    2006-01-01

    The percentage of infested mango fruits of five selected mango varieties was evaluated during three years under field conditions. Three varieties with field resistance to fruit flies had less then 10% of fruits infested. Tommy Atkins, the susceptible commercial check, had 42,9% and the susceptible check had 98.9 % of infested fruits. The three field resistant varieties plus the susceptible commercial check, Tommy Atkins, were further tested in laboratory, under caged conditions, with artificial infestation of Anastrepha obliqua. The attempts of oviposition and the number of pupae developed from each fruit were evaluated. Under caged conditions, the cultivar Alfa maintained its field resistance and Espada Stahl and IAC 111 lost the field resistance and were as susceptible as Tommy Atkins. The attempts of oviposition were positively and highly correlated with the number of pupae developed in the fruits. Non preference for oviposition was confirmed as the main mechanism of resistance of mango fruits to fruit flies. In the absence of a more susceptible variety (no choice test) the cultivar Alfa has kept the resistance (author)

  20. Sphaerionini (Coleoptera, Cerambycidae, Cerambycinae: novos taxons, sinonímia, chaves e nova combinação

    Directory of Open Access Journals (Sweden)

    Ubirajara R Martins

    1990-01-01

    Full Text Available New taxa described: Neomallocera, gen. n., type-species, Mallocera opulenta Newman, 1841; Protomallocera, gen. n., type-species, Mallocera hilairei Gounelle, 1908; Championa chemsaki, sp. n. (Mexico: Chiapas; Parasphaerion, gen. n., type-species, P. granulosum, sp. n. (Suriname; Mephritus quadrimaculatus, sp. n. (Bolivia: Cochabamba. M. castaneus, sp. n. (Peru: Pasco; M. fraterculus, sp. n. (Peru: Cajamarca; Nesostizocera suturalis. sp. n. (Peru and Ecuador; Morphaneflus, gen. n., type-species, M. prolixus, sp. n. (Argentina: Salta, Jujuy; Amethysphaerion eximium, sp. n. (Ecuador; A. jocosum, sp. n. (Brazil: Espírito Santo; A. submetallicum, sp. n. (Brazil: Minas Gerais; A. guarani, sp. n. (Paraguay; Aposphaerion punctulatum, sp. n. (Brazil: Amazonas; Pilisphaerion, gen. n., type-species, P. exoticum, sp. n. (Brazil: Pará; Adiposphaerion, gen n., type-species. A. rubrum, sp. n. (Brazil: Amazonas; Minipsyrassa guanabarina, sp. n. (Brazil: Rio de Janeiro; Sphaerioeme, gen. n., type-species, S. rubristerna, sp. n. (Suriname, Brazil: Goiás, Mato Grosso, Minas Gerais, São Paulo, Paraná; Apoclausirion. gen. n., type-species, A. nigricorne (Brazil: Mato Grosso. Mallocera pickeli Melzer, 1931 is considered a synonym of M. simplex White, 1853. Psyrassa trinidadensis Gilmour, 1963 is transferred to the genus Amethysphaerion. Keys to the genera related with Mallocera and to the species of Amethysphaerion are added.

  1. Genome sequencing of the sweetpotato whitefly Bemisia tabaci MED/Q.

    Science.gov (United States)

    Xie, Wen; Chen, Chunhai; Yang, Zezhong; Guo, Litao; Yang, Xin; Wang, Dan; Chen, Ming; Huang, Jinqun; Wen, Yanan; Zeng, Yang; Liu, Yating; Xia, Jixing; Tian, Lixia; Cui, Hongying; Wu, Qingjun; Wang, Shaoli; Xu, Baoyun; Li, Xianchun; Tan, Xinqiu; Ghanim, Murad; Qiu, Baoli; Pan, Huipeng; Chu, Dong; Delatte, Helene; Maruthi, M N; Ge, Feng; Zhou, Xueping; Wang, Xiaowei; Wan, Fanghao; Du, Yuzhou; Luo, Chen; Yan, Fengming; Preisser, Evan L; Jiao, Xiaoguo; Coates, Brad S; Zhao, Jinyang; Gao, Qiang; Xia, Jinquan; Yin, Ye; Liu, Yong; Brown, Judith K; Zhou, Xuguo Joe; Zhang, Youjun

    2017-05-01

    The sweetpotato whitefly Bemisia tabaci is a highly destructive agricultural and ornamental crop pest. It damages host plants through both phloem feeding and vectoring plant pathogens. Introductions of B. tabaci are difficult to quarantine and eradicate because of its high reproductive rates, broad host plant range, and insecticide resistance. A total of 791 Gb of raw DNA sequence from whole genome shotgun sequencing, and 13 BAC pooling libraries were generated by Illumina sequencing using different combinations of mate-pair and pair-end libraries. Assembly gave a final genome with a scaffold N50 of 437 kb, and a total length of 658 Mb. Annotation of repetitive elements and coding regions resulted in 265.0 Mb TEs (40.3%) and 20 786 protein-coding genes with putative gene family expansions, respectively. Phylogenetic analysis based on orthologs across 14 arthropod taxa suggested that MED/Q is clustered into a hemipteran clade containing A. pisum and is a sister lineage to a clade containing both R. prolixus and N. lugens. Genome completeness, as estimated using the CEGMA and Benchmarking Universal Single-Copy Orthologs pipelines, reached 96% and 79%. These MED/Q genomic resources lay a foundation for future 'pan-genomic' comparisons of invasive vs. noninvasive, invasive vs. invasive, and native vs. exotic Bemisia, which, in return, will open up new avenues of investigation into whitefly biology, evolution, and management. © The Author 2017. Published by Oxford University Press.

  2. Morphology of the spermathecae of twelve species of Triatominae (Hemiptera, Reduviidae) vectors of Chagas disease.

    Science.gov (United States)

    Nascimento, Juliana Damieli; Ribeiro, Aline Rimoldi; Almeida, Larissa Aguiar; de Oliveira, Jader; Mendonça, Vagner José; Cilense, Mário; da Rosa, João Aristeu

    2017-12-01

    Trypanosoma cruzi, the etiological agent of Chagas disease, is transmitted by triatomines that have been described in a large number of studies. Most of those studies are related to external morphology and taxonomy, but some biochemical, genetic and physiological studies have also been published. There are a few publications in the literature about the internal organs of Triatominae, for instance the spermathecae, which are responsible for storing and maintaining the viability of the spermatozoids until the fertilization of the oocytes. This work aims to study the spermathecae of twelve species of triatomines obtained from the Triatominae Insectarium of the Faculty of Pharmaceutical Sciences, UNESP, Araraquara, using optical microscopy and scanning electron microscopy. The spermathecae of the twelve species studied showed three morphological patterns: a) P. herreri sn, P. lignarius, P. megistus, Triatoma brasiliensis, T. juazeirensis, T. sherlocki and T. tibiamaculata have spermathecae with a thin initial portion and an oval-shaped final portion; b) R. montenegrensis, R. nasutus, R. neglectus, R. pictipes and R. prolixus have tubular and winding spermathecae; c) T. infestans has oval spermathecae. In addition to the three morphological patterns, it was noted that each of the twelve species has particular features that differentiate them. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Prevalência, índices de infecção e hábitos alimentares de triatomíneos capturados em uma área de vigilância epidemiológica

    Directory of Open Access Journals (Sweden)

    Vera Lúcia C. Corrêa Rodrigues

    1992-09-01

    Full Text Available Em continuação a estudo anterior, relativo à prevalência e infecção por Trypanosoma cruzi dos triatomíneos capturados na região administrativa de Campinas, SP, os autores apresentam dados do período de 1982-1986, acrescentando informações sobre respastos sangüíneos realizados por 7.785 exemplares. Para tanto, foram utilizados os anti-soros: ave, marsupial, roedor e humano, através dos quais constataram o ecletismo alimentar de Panstrongylus megistus, espécie predominante na região, cujas formas aladas são encontradas com freqüência, infectadas por T. cruzi, nas casas habitadas. Desses, 14,78% reagiram frente ao anti-soro humano. Com Rhodnius neglectus foi observada situação assemelhada, mas com números menos expressivos. Em relação ao Triatoma sórdida, não foi constatada infecção natural e tampouco sinais de ingestão de sangue humano. Foi constatado acentuado aumento de T. arthurneivai nas casas, fruto da provável modificação ocorrida no ambiente natural. No período, foi encontrado Microtiatoma borbai, detectado pela primeira vez no Estado de São Paulo. Ressaltam também a importância da "investigação de foco " nas áreas em fase de vigilância.Prevalence of triatomines and their infection by Trypanosoma cruzi, were studied during 1974-1981, in the Administrative Region of Campinas, São Paulo, Brazil. This investigation was continued (1982-1986, blood meal tests with bird, marsupial, rodent and human antisera having been added. Panstrongylus megistus, predominant in the region, whose winged instars are often found infected by T. cruzi in inhabited houses, displayed and alimentary eclecticism. From a sample of 7,785, 14.78 percent reacted positively with human antisera. A similar, but less marked behaviour was observed in Rhodnius neglectus. Triatoma sordida, the secondmost important species in the Region, was neither demonstrated to be feeding on humans nor to be infected by T. cruzi. Changes in their

  4. Tripanosomiasis americana: determinación de riesgo epidemiológico de transmisión en el municipio de Amalfi, Antioquia American trypanosamiasis: determination of epidemiologic transmission risk in Amalfi, Antioquia, Colombia

    Directory of Open Access Journals (Sweden)

    John Jairo Arboleda

    2001-02-01

    Full Text Available Se presenta por primera vez en antioquia un estudio sobre la enfermedad de Chagas, en el cual se evaluaron simultáneamente los tres componentes fundamentales de esta parasitosis: vector, parásito y reservorio. Se evaluaron 640 domicilios en 9 veredas del municipio de Amalfi, se capturaron 196 triatominos, pertenecientes a las especies Panstrongylus geniculatus (49%, P. rufotuberculatus (47%, Triatoma dispar (3% y Rhodnius pallescens (0.5%. En total se capturaron 33 animales silvestres, pertenecientes a las especies Didelphis marsupialis (8, Marmosa robinsoni (1, Hoplomys gimnurus (3, Dasypus novemcinctus (2, Proechymis sp (13, Oryzomis sp (3, Philander opossum (3, así como 63 perros (Canis lupus. Los indicadores de riesgo de transmisión de Tripanosoma cruzi por triatominos, fueron: dispersión (100%, infestación domiciliaria (14,5%, densidad (30,5%, hacinamiento (204,2% e infección relativa (12,5%. Se obtuvo una alta prevalencia de anticuerpos en los perros de las veredas Montebello (61.1% y La Gardenia (70.0% y serología positiva en un humano adulto. In this paper we report the first Chagas disease study in Antioquia-Colombia, in which the main components of this disease were simultaneously evaluated: vector, parasite and host. Field studies were carried out evaluating 640 houses in nine localities from the municipality of Amalfi; 196 triatomine bugs were captured: Panstrongylus geniculatus (49%, Panstrongylus rufotuberculatus (47%, Triatoma dispar (3% and Rhodnius pallescens (0.5%. Thirty three wild animals were captured: Didelphis marsupialis (8, Marmosa robinsoni (1, Hoplomys gimnurus (3, Dasypus novemcinctus (2, Proechymis sp (13, Oryzomis sp (3, Philander opossum (3 as well as 63 dogs (Canis lupus. Transmission risk indicators for Trypanosoma cruzi were: Dispersion (100%, Domiciliary infestation (14,5%, Insect density (30,5%, crowding (204,2% and Relative infection (12,5%. Of the nine localities studied, Montebello (61.1% and La

  5. Drivers of house invasion by sylvatic Chagas disease vectors in the Amazon-Cerrado transition: A multi-year, state-wide assessment of municipality-aggregated surveillance data.

    Directory of Open Access Journals (Sweden)

    Raíssa N Brito

    2017-11-01

    Full Text Available Insecticide spraying efficiently controls house infestation by triatomine bugs, the vectors of Trypanosoma cruzi. The strategy, however, is ineffective against sylvatic triatomines, which can transmit Chagas disease by invading (without colonizing man-made structures. Despite growing awareness of the relevance of these transmission dynamics, the drivers of house invasion by sylvatic triatomines remain poorly understood.About 12,000 sylvatic triatomines were caught during routine surveillance in houses of Tocantins state, Brazil, in 2005-2013. Using negative binomial regression, information-theoretic model evaluation/averaging, and external model validation, we investigated the effects of regional (Amazon/Cerrado, landscape (preservation/disturbance, and climate covariates (temperature, rainfall on the municipality-aggregated numbers of house-invading Rhodnius pictipes, R. robustus, R. neglectus, and Panstrongylus geniculatus. House invasion by R. pictipes and R. robustus was overall more frequent in the Amazon biome, tended to increase in municipalities with more well-preserved land, and decreased in rainier municipalities. Across species, invasion decreased with higher landscape-disturbance levels and in hotter-day municipalities. Invasion by R. neglectus and P. geniculatus increased somewhat with more land at intermediate disturbance and peaked in average-rainfall municipalities. Temperature effects were more pronounced on P. geniculatus than on Rhodnius spp.We report widespread, frequent house invasion by sylvatic triatomines in the Amazon-Cerrado transition. Our analyses indicate that readily available environmental metrics may help predict the risk of contact between sylvatic triatomines and humans at coarse geographic scales, and hint at specific hypotheses about climate and deforestation effects on those vectors-with some taxon-specific responses and some seemingly general trends. Thus, our focal species appear to be quite sensitive to

  6. Manufacture and qualification of hot roll-clad composites with nickel base cladding material for use in flue gas desulphurization plants. Final report; Herstellung und Qualifizierung warmwalzplattierter Verbundwerkstoffe mit Nickelbasisauflagen fuer den Einsatz in Rauchgasentschwefelungsanlagen. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Kirchheiner, R.; Stenner, F.

    1992-03-16

    Flue gas desulphurization plants (FGD), which have been required by law since 1983, mainly apply wet scrubbing techniques. The chemical reactions taking place in those plants lead to extremely corrosive situations. Unprotected carbon steel surfaces or organic based anticorrosive systems are extremely affected after being in operation for only a few years. NiCrM alloys applied by the chemical industry in comparable situations have proved their efficiency for decades. When such massive components are newly built in FDGs, economic aspects require the use of those NiCrMo alloys in clad form. Within the frame of this project tests included the manufacture of hot roll-clad composites comprising cladding materials of the type NiMo16Cr15W (2.4819) and NiCr21Mo14W (2.4602) on the base steel RST 37-2. Large-sized sheets (10000 x 2000 x 10+2 mm) were made by means of an optimized cladding technique. The behaviour of the cladding material in case of uniform and local corrosion exposure was examined in standard laboratory tests. An increased susceptibility to intercrystalline corrosion was not detected, according to the excellent microstructure. Further laboratory tests under simulated FGD conditions and exposure tests in FGDs in operation permitted the transfer of those positive test results to practical work. The same applies without limitation to the joint-welded state with similar filler material of clad a comparable chemical composition. With respect to their technological behaviour the new hot roll-clad composites correspond to that of solid sheets of NiCrMo alloys; therefore they are qualified for use in flue gas desulphurization plants. (orig./BBR) With 32 refs., 13 tabs., 29 figs. [Deutsch] In den seit 1983 gesetzlich vorgeschriebenen Anlagen zur Rauchgasentschwefelung (REA) werden ueberwiegend nasse Waschverfahren eingesetzt. Die in diesen Anlagen ablaufenden chemischen Reaktionen fuehren zu extrem korrosiven Bedingungen. Ungeschuetzte C-Stahl-Oberflaechen bzw

  7. Microstructure and properties of the heat-resistant chromium steel P91; Gefuege und Eigenschaften des warmfesten Chromstahls P91

    Energy Technology Data Exchange (ETDEWEB)

    Kohlar, Stefanie

    2017-07-01

    spezifizierte warmfeste Chromstahl X10CrMoVNb9-1 gilt auf Grund seiner guten Eigenschaften bei hohen Temperaturen und hohen mechanischen Beanspruchungen als potentieller Werkstoff fuer die Anwendung als Reaktordruckbehaeltermaterial in Kernreaktoren der vierten Generation. Gegenstand dieser Arbeit war die Charakterisierung des Gefueges und der Eigenschaften dieses Werkstoffes. Zu diesem Zweck wurde er metallographisch untersucht und technisch wichtige Kennwerte ermittelt. Es kamen dabei unterschiedliche Aetzmethoden und bildgebende Verfahren zum Einsatz, wobei gerade das neu auf dieses Material angewandte Verfahren der Oxalsaeureaetzung aussagekraeftige Ergebnisse brachte. Zugversuche, Haertepruefungen und Kerbschlagbiegeversuche lieferten mechanisch-technologische Kennwerte. Das bruchmechanische Verhalten wurde mittels Bruchmechanikversuchen an Biege- und Kompaktzugproben ermittelt. Das Hauptaugenmerk lag dabei auf der Untersuchung der Anwendbarkeit der in den Normen ASTM 1921 und ASTM 1820 fuer niedriglegierte Staehle dargestellten Auswerteverfahren. Die Untersuchungen zeigten, dass der P91 erwartungsgemaess ein homogenes martensitisches Gefuege, bestehend aus angelassenem Martensit mit eingelagerten Carbiden und Carbonitiriden, aufweist. Die Lage und Groesse der gefundenen Carbide konnte durch das neu auf diesen Werkstoff angewandte Verfahren der Oxalsaeureaetzung wiedergegeben werden. Die mechanisch-technologischen Versuche zeigten ein fuer einen vergueteten Stahl typisches gutes Festigkeits- und Zaehigkeitsverhalten. Die Anwendung der linear-elastischen Bruchmechanik und der Fliessbruchmechanik ermoeglichten die Ermittlung einer Referenztemperatur nach ASTM 1921-08a, zeigten aber auch, dass die in der ASTM 1820-08 beschriebenen Auswerteverfahren und Geometrien fuer diesen hochlegierten Stahl zu keinen gueltigen Werkstoffkennwerten fuehren. Um die Eignung dieses Werkstoffes fuer kerntechnische Anwendungen weitergehend zu ermitteln, sollte das Bestrahlungs- und

  8. [The vitalism of Paul-Joseph Barthez (1734-1806)].

    Science.gov (United States)

    Han, Hee Jin

    2010-06-30

    In The Logic of Life (1970), Francois Jacob (1920- ), Nobel Prize laureate in Physiology or Medicine (1965), proclaimed the end of vitalism based on the concept of life. More than two decades before this capital sentence condemning vitalism was pronounced, Georges Canguilhem (1904-1995), a French philosopher of medicine, already acknowledged that eighteenth-century vitalism was scientifically retrograde and politically reactionary or counter-revolutionary insofar as it was rooted in the animism of Georg Ernst Stahl (1660-1734). The negative preconception of the term 'vitalism' came to be established as an orthodox view, since Claude Bernard (1813-1878) unfairly criticized contemporary vitalism in order to propagate his idea of experimental medicine. An eminent evolutionary biologist like Ernst Mayr (1904-2005) still defended similar views in This is Biology (1997), arguing that if vitalists were decisive and convincing in their rejection of the Cartesian model (negative heuristics), however they were equally indecisive and unconvincing in their own explanatory endeavors (positive heuristics). Historically speaking, vitalists came to the forefront for their outstanding criticism of Cartesian mechanism and physicochemical reductionism, while their innovative concepts and theories were underestimated and received much less attention. Is it true that vitalism was merely a pseudo-science, representing a kind of romanticism or mysticism in biomedical science? Did vitalists lack any positive heuristics in their biomedical research? Above all, what was actually the so.called 'vitalism'? This paper aims to reveal the positive heuristics of vitalism defined by Paul.Joseph Barthez (1734-1806) who was the founder of the vitalist school of Montpellier. To this end, his work and idea are introduced with regard to the vying doctrines in physiology and medicine. At the moment when he taught at the medical school of Montpellier, his colleagues advocated the mechanism of Rene

  9. Occurrence of synanthropic triatomines (Hemiptera: Reduviidae in the Federal District of Brazil

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    Maicon Hitoshi Maeda

    2012-02-01

    Full Text Available INTRODUCTION: Entomological surveillance of Chagas disease in the Federal District of Brazil (DF, has recorded the following triatomine species: Panstrongylus megistus, P. geniculatus, P. diasi, Rhodnius neglectus, Triatoma pseudomaculata, and T. sordida. We aimed to analyze the spatial and temporal occurrence of triatomine species collected in DF, and their indices of natural infection with trypanosomes. METHODS: The Health State Secretariat of DF recorded triatomines between 2002 and 2010 in 20 administrative regions. This retrospective analysis considered the number of adults and nymphs of each species collected and infected in both intradomicile and peridomicile. RESULTS: A total of 754 triatomines were collected in 252 reported domiciles. Panstrongylus megistus was the most frequent species (65%, followed by T. pseudomaculata (14%. Of the 309 examined insects, only 3 (1% specimens of P. megistus were infected with flagellates morphologically similar to Trypanosoma cruzi. The spatial occurrence indicated a higher diversity of triatomines and frequency of T. sordida in rural areas. Moreover, there was a predominance of P. megistus in urban areas. The number of records of P. megistus in the rainy season was two times higher than that during the dry season. The largest number of triatomines was collected in November. CONCLUSIONS: The presence of P. megistus specimens infected with trypanosomes in domiciles, shows the potential risk of human infection in DF. Thus, it is essential to continue entomological surveillance, intensifying it in the rainy season and in regions of greater occurrence.

  10. Risk factors associated with Trypanosoma cruzi exposure in domestic dogs from a rural community in Panama.

    Science.gov (United States)

    Saldaña, Azael; Calzada, José E; Pineda, Vanessa; Perea, Milixa; Rigg, Chystrie; González, Kadir; Santamaria, Ana Maria; Gottdenker, Nicole L; Chaves, Luis F

    2015-11-01

    Chagas disease, caused by Trypanosoma cruzi infection, is a zoonosis of humans, wild and domestic mammals, including dogs. In Panama, the main T. cruzi vector is Rhodnius pallescens, a triatomine bug whose main natural habitat is the royal palm, Attalea butyracea. In this paper, we present results from three T. cruzi serological tests (immunochromatographic dipstick, indirect immunofluorescence and ELISA) performed in 51 dogs from 24 houses in Trinidad de Las Minas, western Panama. We found that nine dogs were seropositive (17.6% prevalence). Dogs were 1.6 times more likely to become T. cruzi seropositive with each year of age and 11.6 times if royal palms where present in the peridomiciliary area of the dog's household or its two nearest neighbours. Mouse-baited-adhesive traps were employed to evaluate 12 peridomestic royal palms. All palms were found infested with R. pallescens with an average of 25.50 triatomines captured per palm. Of 35 adult bugs analysed, 88.6% showed protozoa flagellates in their intestinal contents. In addition, dogs were five times more likely to be infected by the presence of an additional domestic animal species in the dog's peridomiciliary environment. Our results suggest that interventions focused on royal palms might reduce the exposure to T. cruzi infection.

  11. Chromosomal divergence and evolutionary inferences in Rhodniini based on the chromosomal location of ribosomal genes

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    Sebastian Pita

    2013-05-01

    Full Text Available In this study, we used fluorescence in situ hybridisation to determine the chromosomal location of 45S rDNA clusters in 10 species of the tribe Rhodniini (Hemiptera: Reduviidae: Triatominae. The results showed striking inter and intraspecific variability, with the location of the rDNA clusters restricted to sex chromosomes with two patterns: either on one (X chromosome or both sex chromosomes (X and Y chromosomes. This variation occurs within a genus that has an unchanging diploid chromosome number (2n = 22, including 20 autosomes and 2 sex chromosomes and a similar chromosome size and genomic DNA content, reflecting a genome dynamic not revealed by these chromosome traits. The rDNA variation in closely related species and the intraspecific polymorphism in Rhodnius ecuadoriensis suggested that the chromosomal position of rDNA clusters might be a useful marker to identify recently diverged species or populations. We discuss the ancestral position of ribosomal genes in the tribe Rhodniini and the possible mechanisms involved in the variation of the rDNA clusters, including the loss of rDNA loci on the Y chromosome, transposition and ectopic pairing. The last two processes involve chromosomal exchanges between both sex chromosomes, in contrast to the widely accepted idea that the achiasmatic sex chromosomes of Heteroptera do not interchange sequences.

  12. Species of the subfamily Triatominae Jeannel, 1919 (Hemiptera: Reduviidae present in the Collection of Chagas Disease Vectors (FIOCRUZ-COLVEC, State of Minas Gerais

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    Rita de Cássia Moreira de Souza

    2014-12-01

    Full Text Available Introduction Biological collections are depositories of information on different species and contribute to the knowledge, protection, conservation and maintenance of biodiversity. Methods A list of triatomine species currently included in the Collection of Chagas Disease Vectors (FIOCRUZ-COLVEC was prepared from the database made available by the Reference Center on Environmental Information. Results COLVEC curatorship houses 4,778 specimens of triatomines, of which 811 come from other American countries (Argentina, Bolivia, Colombia, Costa Rica, the United States of America, Guatemala, Mexico, Peru, Uruguay and Venezuela and 3,967 are autochthonous from Brazil. Altogether, 56 species of Chagas disease vectors are represented in the COLVEC: two species of the Tribe Cavernicolini Usinger, 1944; fifteen species of the tribe Rhodniini Pinto, 1926, of which 12 are of the genus Rhodnius and 3 are of the genus Psamolestes; and 39 species of the tribe Triatomini Jeannel, 1919, represented by the genus Dipetalogaster, two species of the genus Eratyrus, two of the genus Meccus, seven of the genus Panstrongylus and 27 of the genus Triatoma. Conclusions This list provides important data on the diversity of triatomines currently included in COLVEC, including the expanded area of Panstrongylus lutzi occurrence in the municipalities Pirapora and Januária, State of Minas Gerais. The maintenance and expansion of the collection ensures the preservation of biodiversity and further studies.

  13. Infestation of arboreal nests of coatis by triatomine species, vectors of Trypanosoma cruzi, in a large Neotropical wetland.

    Science.gov (United States)

    de Lima, Juliane Saab; Rocha, Fabiana Lopes; Alves, Fernanda Moreira; Lorosa, Elias Seixas; Jansen, Ana Maria; de Miranda Mourão, Guilherme

    2015-12-01

    The coati (Nasua nasua, Carnivora) is a medium-sized mammal common in the Pantanal of Brazil. Unlike most mammals, coatis construct arboreal nests used for resting and reproduction. In this region, the coati is an important host of Trypanosoma cruzi, the causative agent of Chagas disease. There are two possible routes through coatis can be infected by T. cruzi: the oral route or the vectorial route. However, the relative importance of each of these routes in the infection of coatis and its role in the sylvatic cycle of the parasite are unknown. Our objectives were to investigate: (i) whether coati nests were infested by triatomine bugs, (ii) what species were frequent in the nests, (iii) whether the triatomines in nests were infected by T. cruzi, and (iv) what were the food resources of these triatomines. Eight of the 24 nests sampled were infested with triatomines, a total of 37 specimens of at least two species (Rhodnius stali and Triatoma sordida). In one nest, R. stali and T. sordida co-occurred and both fed on multiple resources, including coatis. This is the first report of triatomines occurring in arboreal nests of coatis. The co-occurrence of two different genera of triatomine vectors and coatis within the limited space of the coati nests provide multiple opportunities for the exchange of the protozoan parasite through both the vectorial and oral transmission routes. © 2015 The Society for Vector Ecology.

  14. Geographic Distribution of Chagas Disease Vectors in Brazil Based on Ecological Niche Modeling

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    Rodrigo Gurgel-Gonçalves

    2012-01-01

    Full Text Available Although Brazil was declared free from Chagas disease transmission by the domestic vector Triatoma infestans, human acute cases are still being registered based on transmission by native triatomine species. For a better understanding of transmission risk, the geographic distribution of Brazilian triatomines was analyzed. Sixteen out of 62 Brazilian species that both occur in >20 municipalities and present synanthropic tendencies were modeled based on their ecological niches. Panstrongylus geniculatus and P. megistus showed broad ecological ranges, but most of the species sort out by the biome in which they are distributed: Rhodnius pictipes and R. robustus in the Amazon; R. neglectus, Triatoma sordida, and T. costalimai in the Cerrado; R. nasutus, P. lutzi, T. brasiliensis, T. pseudomaculata, T. melanocephala, and T. petrocchiae in the Caatinga; T. rubrovaria in the southern pampas; T. tibiamaculata and T. vitticeps in the Atlantic Forest. Although most occurrences were recorded in open areas (Cerrado and Caatinga, our results show that all environmental conditions in the country are favorable to one or more of the species analyzed, such that almost nowhere is Chagas transmission risk negligible.

  15. Prevalence, Genetic Characterization, and 18S Small Subunit Ribosomal RNA Diversity of Trypanosoma rangeli in Triatomine and Mammal Hosts in Endemic Areas for Chagas Disease in Ecuador.

    Science.gov (United States)

    Ocaña-Mayorga, Sofia; Aguirre-Villacis, Fernanda; Pinto, C Miguel; Vallejo, Gustavo A; Grijalva, Mario J

    2015-12-01

    Trypanosoma rangeli is a nonpathogenic parasite for humans; however, its medical importance relies in its similarity and overlapping distribution with Trypanosoma cruzi, causal agent of Chagas disease in the Americas. The genetic diversity of T. rangeli and its association with host species (triatomines and mammals) has been identified along Central and the South America; however, it has not included data of isolates from Ecuador. This study reports infection with T. rangeli in 18 genera of mammal hosts and five species of triatomines in three environments (domestic, peridomestic, and sylvatic). Higher infection rates were found in the sylvatic environment, in close association with Rhodnius ecuadoriensis. The results of this study extend the range of hosts infected with this parasite and the geographic range of the T. rangeli genotype KP1(-)/lineage C in South America. It was not possible to detect variation on T. rangeli from the central coastal region and southern Ecuador with the analysis of the small subunit ribosomal RNA (SSU-rRNA) gene, even though these areas are ecologically different and a phenotypic subdivision of R. ecuadoriensis has been found. R. ecuadoriensis is considered one of the most important vectors for Chagas disease transmission in Ecuador due to its wide distribution and adaptability to diverse environments. An extensive knowledge of the trypanosomes circulating in this species of triatomine, and associated mammal hosts, is important for delineating transmission dynamics and preventive measures in the endemic areas of Ecuador and Northern Peru.

  16. [Anatomy and histology of salivary glands of Triatominae].

    Science.gov (United States)

    Lacombe, D

    1999-01-01

    Histological studies upon the salivary glands of ten species of triatomine bugs were performed looking for their number and structural organization in different genera. It was possible to evaluate the celular epithelium type of each gland, as well as the merocrine and apocrine secretions of the glands. Secretion run until the hilo and after to salivary pump and hypofaringe. The glandular components, D1, D2 and D3 are always present in the Triatoma, Panstrongylus and Diptelogaster but in Rhodnius there are only the first two pairs of glands. The salivary channels and the hilo are analyzed by histology. The whole pair D3 has a clear valve that regularizes the exit of the secretions to the hilo. According to the genus the valves appear in different locations. They have low and dense epithelium, and their nucleus are rich in chromatin. The secondary channels leaving these valves, are very different, with clear chitinous ringer, low level of chromatin in the nucleus and homogeneous cytoplasm.

  17. Prevalence, Genetic Characterization, and 18S Small Subunit Ribosomal RNA Diversity of Trypanosoma rangeli in Triatomine and Mammal Hosts in Endemic Areas for Chagas Disease in Ecuador

    Science.gov (United States)

    Ocaña-Mayorga, Sofia; Aguirre-Villacis, Fernanda; Pinto, C. Miguel; Vallejo, Gustavo A.

    2015-01-01

    Abstract Trypanosoma rangeli is a nonpathogenic parasite for humans; however, its medical importance relies in its similarity and overlapping distribution with Trypanosoma cruzi, causal agent of Chagas disease in the Americas. The genetic diversity of T. rangeli and its association with host species (triatomines and mammals) has been identified along Central and the South America; however, it has not included data of isolates from Ecuador. This study reports infection with T. rangeli in 18 genera of mammal hosts and five species of triatomines in three environments (domestic, peridomestic, and sylvatic). Higher infection rates were found in the sylvatic environment, in close association with Rhodnius ecuadoriensis. The results of this study extend the range of hosts infected with this parasite and the geographic range of the T. rangeli genotype KP1(−)/lineage C in South America. It was not possible to detect variation on T. rangeli from the central coastal region and southern Ecuador with the analysis of the small subunit ribosomal RNA (SSU-rRNA) gene, even though these areas are ecologically different and a phenotypic subdivision of R. ecuadoriensis has been found. R. ecuadoriensis is considered one of the most important vectors for Chagas disease transmission in Ecuador due to its wide distribution and adaptability to diverse environments. An extensive knowledge of the trypanosomes circulating in this species of triatomine, and associated mammal hosts, is important for delineating transmission dynamics and preventive measures in the endemic areas of Ecuador and Northern Peru. PMID:26645579

  18. Trypanosoma cruzi: Correlations of Biological Aspects of the Life Cycle in Mice and Triatomines

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    Lima Valdirene S

    1999-01-01

    Full Text Available The infection pattern in Swiss mice and Triatomine bugs (Rhodnius neglectus of eleven clones and the original stock of a Trypanosoma cruzi isolate, derived from a naturally infected Didelphis marsupialis, were biochemically and biologically characterized. The clones and the original isolate were in the same zymodeme (Z1 except that two clones were found to be in zymodeme 2 when tested with G6PDH. Although infective, neither the original isolate nor the clones were highly virulent for the mice and lesions were only observed in mice infected with the original stock and one of the clones (F8. All clones and the original isolate infected bugs well while only the original isolate and clones E2 and F3 yielded high metacyclogenesis rates. An observed correlation between absence of lesions in the mammal host and high metacyclogenesis rates in the invertebrate host suggest a evolutionary trade off i.e. a fitness increase in one trait which is accompanied by a fitness reduction in a different one. Our results suggest that in a species as heterogeneous as T. cruzi, a cooperation effect among the subpopulations should be considered.

  19. Investigación de vectores y reservorios en brote de Chagas agudo por posible transmisión oral en Aguachica, Cesar, Colombia

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    Hugo Soto

    2014-04-01

    Full Text Available Colombia tiene un registro de 11 casos de Chagas agudo y 80 casos por contaminación oral con Trypanosoma cruzi. Este trabajo analiza los hallazgos entomológicos y parasitológicos del brote de Aguachica, Cesar, en 2010. Un grupo interdisciplinario de profesionales de la salud y de universidades regionales realizó las pruebas de laboratorio a los pacientes y el estudio del foco de transmisión. Se detectaron 11 casos agudos de enfermedad de Chagas en una sola familia con vivienda sin triatominos domiciliados y, Rhodnius pallescens, Pantrongylus geniculatus, Eratyrus cuspidatus y dos Didelphis marsupialis infectados con T. cruzi en palmas de Attalea butyracea y Elaeis oleifera del área urbana de Aguachica. Se analiza la participación del R. pallescens y el rol de las palmas en el ciclo silvestre de T. cruzi y para la transmisión oral de la enfermedad de Chagas. Incursiones esporádicas de R. pallescens, P. geniculatus y E. cuspidatus silvestres desde palmas cercanas al domicilio humano pueden provocar brotes cada vez más frecuentes de Chagas oral.

  20. Epidemiology of Chagas disease in Ecuador. A brief review

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    Aguilar V H Marcelo

    1999-01-01

    Full Text Available Chagas disease is a complex public health problem that has been underestimated in Ecuador. Here we review the relevant published information, and present unpublished and new data that help to understand the current Chagas disease epidemiological situation and its evolution in the country. Three main characteristics have been identified: (i persistence of Trypanosoma cruzi transmission in already known foci; (ii a marked endemicity in some urban areas of Guayaquil; and (iii the transformation of new Amazon foci into truly endemic areas. The situation in other suspect areas remains uncertain. Five Triatominae species have been implicated in the transmission of T. cruzi to people in Ecuador (Triatoma dimidiata, Rhodnius ecuadoriensis, R. pictipes, R. robustus and Panstrongylus geniculatus, but some others may also play a role in some areas (P. rufotuberculatus, P. howardi, T. carrioni and P. chinai. Other Triatominae reported seem to have little or no epidemiological relevance (T. venosa, T. dispar, Eratyrus mucronatus, E. cuspidatus, P. lignarius and Cavernicola pilosa. High frequency of acute cases and severe chronic disease has been observed. Although cardiomyopathy is more frequent, serious digestive disease is also present. It is estimated that around 120,000-200,000 people may be infected. 2.2 to 3.8 million people are estimated to live under transmission risk conditions.

  1. Biogeography of Triatominae (Hemiptera: Reduviidae in Ecuador: implications for the design of control strategies

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    Abad-Franch Fernando

    2001-01-01

    Full Text Available Chagas disease control strategies strongly depend on the triatomine vector species involved in Trypanosoma cruzi transmission within each area. Here we report the results of the identification of specimens belonging to various species of Triatominae captured in Ecuador (15 species from 17 provinces and deposited in the entomological collections of the Catholic University of Ecuador (Quito, Instituto Oswaldo Cruz (Brazil, the Natural History Museum London (UK, the London School of Hygiene and Tropical Medicine (UK, the National Institute of Hygiene (Quito, and the Vozandes Hospital (Quito. A critical review of published information and new field records are presented. We analysed these data in relation to the life zones where triatomines occur (11 life zones, excluding those over 2,200 m altitude, and provide biogeographical maps for each species. These records are discussed in terms of epidemiological significance and design of control strategies. Findings relevant to the control of the main vector species are emphasised. Different lines of evidence suggest that Triatoma dimidiata is not native to Ecuador-Peru, and that synanthropic populations of Rhodnius ecuadoriensis in southern Ecuador-northern Peru might be isolated from their sylvatic conspecifics. Local eradication of T. dimidiata and these R. ecuadoriensis populations might therefore be attainable. However, the presence of a wide variety of native species indicates the necessity for a strong longitudinal surveillance system.

  2. Book review of Insect Symbiosis. Volume 2. Bourtzis, K.A. and Miller, T.A. editros. 2006 CRC Press, Taylor and Francis Group, Boca Raton, FL, 276 pp. ISBN 0-8493-1286-8

    International Nuclear Information System (INIS)

    Hoy, M.A.

    2007-01-01

    There are several definitions of symbiosis, but in this book it involves an association where one organism (the symbiont) lives within or on the body of another organism (the host), regardless of the actual effect on the host. Some symbioses are mutualistic, some parasitic, and some involve commensalism, in which one partner derives some benefit without either harming or benefiting the other. This is the second volume in this exciting and rapidly advancing topic by these editors. The first volume was published in 2003 and during the intervening three years additional data have been produced that make this book a useful addition to your library. The first book provided chapters that provided an overview of insect symbiosis, discussions of the primary aphid symbiont Buchnera and other aphid symbionts, symbiosis in tsetse, symbionts in the weevil Sitophilus , the possible use of paratransgenic symbionts of Rhodnius prolixis to prevent disease transmission, bark beetle and fungal symbiosis, symbionts of tephritid fruit flies, symbionts affecting termite behavior, an overview of microsporidia as symbionts (parasites?) of insects, an overview of a newly discovered bacterium that causes sex-ratio distortion in insects and mites (from the Bacteroides group), symbionts that selectively kill male insects, and several chapters on the ubiquitous endosymbiont Wolbachia

  3. DataTri, a database of American triatomine species occurrence

    Science.gov (United States)

    Ceccarelli, Soledad; Balsalobre, Agustín; Medone, Paula; Cano, María Eugenia; Gurgel Gonçalves, Rodrigo; Feliciangeli, Dora; Vezzani, Darío; Wisnivesky-Colli, Cristina; Gorla, David E.; Marti, Gerardo A.; Rabinovich, Jorge E.

    2018-04-01

    Trypanosoma cruzi, the causative agent of Chagas disease, is transmitted to mammals - including humans - by insect vectors of the subfamily Triatominae. We present the results of a compilation of triatomine occurrence and complementary ecological data that represents the most complete, integrated and updated database (DataTri) available on triatomine species at a continental scale. This database was assembled by collecting the records of triatomine species published from 1904 to 2017, spanning all American countries with triatomine presence. A total of 21815 georeferenced records were obtained from published literature, personal fieldwork and data provided by colleagues. The data compiled includes 24 American countries, 14 genera and 135 species. From a taxonomic perspective, 67.33% of the records correspond to the genus Triatoma, 20.81% to Panstrongylus, 9.01% to Rhodnius and the remaining 2.85% are distributed among the other 11 triatomine genera. We encourage using DataTri information in various areas, especially to improve knowledge of the geographical distribution of triatomine species and its variations in time.

  4. Molecular epidemiology of Trypanosoma cruzi and Triatoma dimidiata in costal Ecuador.

    Science.gov (United States)

    Wong, Yim Yan; Sornosa Macias, Karen Jeniffer; Guale Martínez, Doris; Solorzano, Luis F; Ramirez-Sierra, Maria Jesus; Herrera, Claudia; Dumonteil, Eric

    2016-07-01

    Chagas disease is a neglected tropical disease caused by the protozoan parasite Trypanosoma cruzi. In Ecuador, Triatoma dimidiata and Rhodnius ecuadoriensis are the main vector species, responsible for over half of the cases of T. cruzi infection in the country. T. dimidiata is believed to have been introduced in Ecuador during colonial times, and its elimination from the country is thus believed to be feasible. We investigated here the molecular ecology of T. dimidiata and T. cruzi in costal Ecuador to further guide control efforts. Analysis of the Internal Transcribed Spacer 2 (ITS-2) of 23 specimens from Progreso, Guayas, unambiguously supported the likely importation of T. dimidiata from Central America to Ecuador. The observation of a very high parasite infection rate (54%) and frequent feeding on humans (3/5) confirmed a continued risk of transmission to humans. All genotyped parasites corresponded to TcI DTU and Trypanosoma rangeli was not detected in T. dimidiata. TcI subgroups corresponded to TcIa (25%), and mixed infections with TcIa and TcId (75%). Further studies should help clarify T. cruzi genetic structure in the country, and the possible impact of the introduction of T. dimidiata on the circulating parasite strains. The elevated risk posed by this species warrants continuing efforts for its control, but its apparent mobility between peridomestic and domestic habitats may favor reinfestation following insecticide spraying. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Applying micromechanic failure models for description of failure modes in the ductile-brittle transition region; Einsatz mikromechanischer Schaedigungsmodelle im sproed-duktilen Uebergangsbereich

    Energy Technology Data Exchange (ETDEWEB)

    Bernauer, G.

    1997-07-01

    The work reported was to examine whether the modified Gurson model and the Beremin model can be applied to the brittle-ductile transition region of a ferritic steel, and whether the material`s behaviour can be characterized with a failure model integrating the two models mentioned above into one. Any possible improvements of this approach were to be found. The report at first gives a brief list of terminology and formulas used. Chapter 3 explains the microscopic processes typically observed in the transition region in connection with the failure modes of ductile fracture and cleavage fracture, and shows possible approaches for modelling. Chapter 4 defines the specimens and materials, and chapter 5 explains the experiments as well as the microscopic analyses of the fracture surfaces. Chapter 6 presents subsequent calculations representing the processes observed. Based on the stress distributions thus derived, the Beremin model is re-examined for further development. Chapter 7 summarizes the results obtained. (orig./CB) [Deutsch] Ziel der Arbeit ist, zu untersuchen, ob das modifizierte Gurson-Modell und das Beremin-Modell im sproed-duktilen Uebergangsbereich eines ferritischen Stahls einsetzbar sind und ob das Werkstoffverhalten mit einem aus beiden Modellen kombinierten Schaedigungsmodell berechnet werden kann. Gegebenenfalls sind Verbesserungen herbeizufuehren. Die vorliegende Arbeit beginnt mit einer kurzen Einfuehrung der verwendeten Begriffe und Formalismen. In Kap. 3 werden die mikroskopischen Vorgaenge bei den im Uebergangsbereich typischerweise auftretenden Versagensarten duktiler Bruch und Spaltbruch vorgestellt und verschiedene Moeglichkeiten ihrer Modellierung aufgezeigt. Nach der Vorstellung des Probenwerkstoffs werden in Kap. 4 die Experimente beschrieben und die mikroskopischen Untersuchungen der Bruchflaechen in Kap. 5 dargestellt. Die Nachrechnungen der Experimente werden in Kap. 6 vorgestellt. Auf der Grundlage der dadurch bereitgestellten

  6. Detection of Prion Proteins and TSE Infectivity in the Rendering and Biodiesel Manufacture Processes

    Energy Technology Data Exchange (ETDEWEB)

    Brown, R.; Keller, B.; Oleschuk, R. [Queen' s University, Kingston, Ontario (Canada)

    2007-03-15

    This paper addresses emerging issues related to monitoring prion proteins and TSE infectivity in the products and waste streams of rendering and biodiesel manufacture processes. Monitoring is critical to addressing the knowledge gaps identified in 'Biodiesel from Specified Risk Material Tallow: An Appraisal of TSE Risks and their Reduction' (IEA's AMF Annex XXX, 2006) that prevent comprehensive risk assessment of TSE infectivity in products and waste. The most important challenge for monitoring TSE risk is the wide variety of sample types, which are generated at different points in the rendering/biodiesel production continuum. Conventional transmissible spongiform encephalopathy (TSE) assays were developed for specified risk material (SRM) and other biological tissues. These, however, are insufficient to address the diverse sample matrices produced in rendering and biodiesel manufacture. This paper examines the sample types expected in rendering and biodiesel manufacture and the implications of applying TSE assay methods to them. The authors then discuss a sample preparation filtration, which has not yet been applied to these sample types, but which has the potential to provide or significantly improve TSE monitoring. The main improvement will come from transfer of the prion proteins from the sample matrix to a matrix compatible with conventional and emerging bioassays. A second improvement will come from preconcentrating the prion proteins, which means transferring proteins from a larger sample volume into a smaller volume for analysis to provide greater detection sensitivity. This filtration method may also be useful for monitoring other samples, including wash waters and other waste streams, which may contain SRM, including those from abattoirs and on-farm operations. Finally, there is a discussion of emerging mass spectrometric methods, which Prusiner and others have shown to be suitable for detection and characterisation of prion proteins (Stahl

  7. Thermal protection and refurbishment of an old building. Lectures; Waermeschutz und Altbausanierung. Vortraege

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    Within the 22nd Hanseatic Reconstruction Symposium at the Baltic Seaside Heringsdorf/Usedom (Federal Republic of Germany) from 3rd to 5th November 2011, the following lectures were held: (1) Energetic refurbishment possibilities for building within existing properties by means of representative examples (F. Deitschum); (2) Constructional thermal insulation and indoor climate - for the good of the environment? (S. Groer); (3) Innovative insulating materials for the structural refurbishment? (O. Fechner); (4) Energetic half-timbering refurbishment (K. Lissner); (5) Wooden solar facades for existing buildings (U. Schwarz); (6) Timber beam bowls in a historic brickwork (U. Mueller); (7) Timber beam bowls and interior insulation (U. Ruisinger); (8) Innovative solutions for cavity filling insulations (A. Stefenelli); (9) Thermal insulating plaster - also for historical buildings (T. Stahl); (10) Experimental tension analysis of the structural behaviour of historical cross vaults (A.-J. Petereit); (10) Investigation of the increase of the flexural strength of stonework constructions with self-compacting steel fibre reinforced concrete (D. Haessler); (11) Dry and dense - the modified WTA leaflet 4-6, 'Subsequent sealing of components in contact with soil' - Content and innovations (R. Spirgatis); (12) What does the new standard DIN 68800 hold? (H. Willeitner); (13) News from the standard DIN 18195 waterproofing of buildings (H.-P. Sommer); (14) Liability of planning of the offering entrepreneur (H. Immoor); (15) Climate change and preservation of structures (W. Zillig); (16) Typical problems and deficiencies of the energetic refurbishment of old store buildings (H. Boehmer); (17) When do ex post horizontal sealings with injection agents make sense - Fundamentals for evaluation, planning and execution (F.-J. Hoelzen); (18) Drying up behaviour of stonework of different quality and at different variants of insulation (F. Antretter).

  8. Relationship of species Piper based on morphological and leaf essential oils characters in Yogyakarta

    Directory of Open Access Journals (Sweden)

    PURNOMO

    2005-01-01

    Full Text Available Some of Piper species were used for traditional medicines and condiments. The leaf essential oil (terpenoid of those Piper species usually were used as a main component in traditional medicine. The taxonomycal study was aimed to determined Piper species relationships based on morphological and leaf essential oils characters. The plants were obtained by exploring this province, and samples were collected for identification and leaf essential oils isolation purposes. Species identification were carried out based on identification key (Backer and Bakhuizen v.d. Brink, 1965; Heyne, 1987; Shaorong, 1982. The isolation of leaf essential oils was carried out using Stahl destillation method, and their composition were interpreted with liquid gas chromatography, using caryophyllene and -pinene as a standard of essential oils component. Dendrogram, which showed phenetic relationships among those species, were obtained by hierarchical cluster analysis method. Results of the research showed that there were 8 species found as cultivated plants in Yogyakarta, which were P. miniatum Bl., P. betle L., P. recurvum Bl., P. aduncum L., P. nigrum L., P. cubeba L.f., P. retrofractum Vahl., and P. sarmentosum Roxb. Ex Hunter. Relationship between species of Piper based on morphological character showed that P. aduncum and P. sarmentosum at the same cluster on 69.2% similarity level, and 40.4% similarity level to the other clusters. Relationsips between species of Piper based on leaf essential oils character resulted the difference cluster among the species, P. retrofractum separated from the other species at 45.5% similarity level, P. aduncum and P. cubeba indicated the higest similarity level (81.5%.

  9. Basic elements for breast screening programs for Rwanda

    International Nuclear Information System (INIS)

    Abenanye, Emmanuel

    2015-02-01

    Mammography refers to the X-ray examination of the human breast, and is considered the single most important diagnostic tool in the early detection of breast cancer, which is by far the most common cancer among women. There is good evidence from clinical trials, that mammographic screening can reduce the breast cancer mortality with about 30%. The side effects include a small and age related risk of carcinogenesis due to the exposure of the glandular tissues in the breast to ionizing radiation. As for all X-ray examinations, and of special importance when investigating large populations of asymptomatic women, the relationship between radiation risk and diagnostic accuracy in mammography must be optimized. The overall objective of this thesis was to investigate and improve methods for average glandular dose (AGD) and image quality evaluation in mammography and provide some practical guidance. To assess the behavioral factors influencing breast screening the best set up of the mammography unit as well as equipment construction and the skills of people operating the machines in terms of the radiation protection screening programs. There has been doubts about the efficiency of so called service screening, i.e. routine screening programs (Sjonell and Stahle, 1999), but there is evidence suggesting a reduction of breast cancer mortality similar to that observed in the randomised trials (Duffy et al. 2002). However no study has been carried out in Rwanda of this nature to see what are the basic breast screening elements and behavioral elements that influence it. Therefore, the factors that influence women's mammography screening behavior is an important issue to be uncovered, in order to facilitate the understanding of such a behavior. This report sets out to investigate the factors that influence participation in mammography screening in Rwanda. Such an investigation aims to raise the awareness of health care providers of the factors that influence Rwanda's women

  10. Knieendoprothetik - Update

    Directory of Open Access Journals (Sweden)

    Dorn U

    2008-01-01

    Full Text Available Weltweit hat in den letzten 10 Jahren die Zahl der Knieendoprothesen-Implantationen stark zugenommen. Nach relativ kurzer Zeit wird durch die Operation eine erhebliche Verbesserung bezogen auf Schmerzbelastung, Gelenksfunktion und Lebensqualität erzielt. Minimal-invasive Zugänge in Kombination mit dazu neu entwickelten Instrumenten beeinträchtigen die Muskelfunktion weniger als der mediale parapatellare Standardzugang und verkürzen die frühe Rehabilitationsphase. Der Einsatz der Navigation erleichtert die präzise Positionierung der Implantate. Sowohl für die minimal-invasive Implantationstechnik als auch für die navigationsunterstützte Technik fehlen noch Ergebnisse, die gegenüber konventioneller Technik bessere Funktion und längere Standzeit dokumentieren. Moderne Prothesen ermöglichen eine Rotation des Unterschenkels entweder durch asymmetrische Formgebung der Femurkondylen oder durch die Rotation der Polyethylenplattform auf der Tibiakomponente bei Prothesen mit konformer Kondylengestaltung. Femur- und Tibiakomponenten mit rotierender Plattform sind aus CoCr-Stahl, Tibiakomponenten mit fest montiertem Polyethylenteil sind meist aus Titanlegierungen gefertigt. In den letzten Jahren werden bei Patienten mit bekannter Metallallergie (insbesondere Nickelallergie spezielle Implantate aus oberflächenbeschichtetem Titan oder Zirkonium eingesetzt. Cross-linked Polyethylen hat noch nicht die gleiche Verbreitung gefunden wie bei Hüftimplantaten. Prothesen mit erhöhter Flexionsmöglichkeit gewannen in letzter Zeit an Bedeutung. Der Einsatz von Halbschlitten-Prothesen ist durch minimal-invasive Zugänge und verbesserte Instrumente wieder populärer geworden. Die Vielfalt modularer Endoprothesensysteme verschiedener Hersteller hat insbesondere Revisionsoperationen leichter gemacht. Dadurch sind auch nach Wechseloperationen ähnliche Ergebnisse zu erzielen wie nach primärer Implantation.

  11. Radiography in construction and combination of other NDT methods; Radiografie im Bauwesen und Kombination anderer ZfP-Verfahren

    Energy Technology Data Exchange (ETDEWEB)

    Hasenstab, Andreas [Ingenieurbuero Dr. Hasenstab GmbH, Augsburg (Germany); Redmer, B. [Bundesanstalt fuer Materialforschung- und pruefung (BAM), Berlin (Germany)

    2016-05-01

    Radiography is in material examination one of the important research methods. So in the steel and plant construction a variety of studies are carried out. In construction, the dominance is the investigations with radar, ultrasonic echo and so in this contribution especially applications with radiographic methods are discribed. Furthermore the combination with different NDT methods should be presented. In all examples there was a combination of radiography and other non-destructive testing methods. In the first example, there is a combination of radiography with ultrasound echo and drilling resistance to an old oak beam from the St. Mary´s church in Lutherstadt Wittenberg (Germany). Measurements by reinforcement locating and radiography of steel plates in the vault of castle Lustheim near Munich and studies using radar and radiography at a temple in the Pergamon Museum in Berlin round off the examples. [German] Die Radiografie stellt in der Materialuntersuchung eine der bedeutendsten Untersuchungsmethoden dar. So werden im Stahl- und Anlagenbau eine Vielzahl von Untersuchungen durchgefuehrt. Im Bauwesen liegt die Dominanz der Untersuchungen bei den Verfahren Radar, Ultraschallecho und so sollen im folgenden Beitrag vor allem Anwendungsbeispiele mit radiographischen Methoden beschrieben werden. Weiter soll die Kombination unterschiedlicher ZfP-Verfahren dargestellt werden. Bei allen Beispielen kam es zu einer Kombination von Radiografie mit anderen zerstoerungsfreien Pruefverfahren. Im ersten Beispiel kommt es zu einer Kombination von Radiografie mit Ultraschallecho und Bohrwiderstand an einem alten Eichenbalken aus der Marienkirche aus Lutherstadt Wittenberg. Messungen mittels Bewehrungsortung und Radiografie an Stahllaschen im Gewoelbe des Schlosses Lustheim bei Muenchen und Untersuchungen mittels Radar und Radiografie an einem Tempel im Pergamonmuseum in Berlin runden die Beispiele ab.

  12. Diamond brazing - interfacial reactions and wetting; Loeten von Diamant - Grenzflaechenreaktionen und Benetzung

    Energy Technology Data Exchange (ETDEWEB)

    Tillmann, W.; Osmanda, A.M.; Yurchenko, S. [Lehrstuhl fuer Werkstofftechnologie, Universitaet Dortmund, Leonhard-Euler-Str. 2, 44227 Dortmund (Germany); Theisen, W. [Ruhr-Universitaet Bochum, Lehrstuhl Werkstofftechnik (Germany)

    2005-08-01

    Diamond tools are increasingly gaining importance as cutting materials for various construction materials. The quality of synthetic diamonds, monocrystalline as well as polycrystalline or CVD-diamonds has been significantly improved over the last years. Integrating these cutting materials requires adequate joining technologies that produce sound joints without exposing the temperature sensitive diamond to too elevated temperatures. The paper highlights current developments in the joining of synthetic diamonds to steel and cemented carbide. Owing to their covalent atomic bonding diamonds cannot easily be wetted and joined by employing conventional brazing alloys. Hence, active agents are needed to foster an interfacial reaction. Different active filler concepts are presented and discussed regarding their joint formation. The brazing temperatures influence not only possible diamond degradation but also the interfacial decomposition of the diamond due to the formation of corresponding reaction layers.Active brazing, monocrystalline. (Abstract Copyright [2005], Wiley Periodicals, Inc.) [German] Diamantwerkstoffe erlangen zunehmend Bedeutung als Schneidmaterialien in Diamantwerkzeugen fuer die Bearbeitung verschiedener Konstruktionswerkstoffe. Die Qualitaet von synthetischen Diamanten, sowohl monokristallinen als auch polykristallinen oder CVD-Diamantschichten konnte in den letzten Jahren deutlich verbessert werden. Die Integration dieser Schneidstoffe erfordert eine angepasste Fuegetechnologie, die fehlerfreie Verbunde bereitstellt, ohne die gegenueber hohen Temperaturen empfindlichen Diamanten zu hohen Temperaturen auszusetzen. Der Beitrag zeigt aktuelle Entwicklungen in der Fuegetechnik von synthetischen Diamanten mit Stahl und Hartmetall auf. Infolge ihrer kovalenten atomaren Bindungen koennen Diamanten nicht ohne weiteres mit herkoemmlichen Lotwerkstoffen benetzt und gefuegt werden. Daher sind reaktive Elemente notwendig, die eine Grenzflaechenreaktion forcieren

  13. Constitution, microstructure, mechanical properties, and performance of magnetron-sputtered carbon films with additions of silicon

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, C. [Forschungszentrum Karlsruhe GmbH, Institut fuer Materialforschung I, Postfach 3640, 76021 Karlsruhe (Germany); Leiste, H.; Stueber, M.; Ulrich, S.; Holleck, H.

    2003-11-01

    Amorphous carbon films with additions of silicon were deposited by non-reactive magnetron sputtering on WC-Co hard metal and on silicon substrates. The targets were hot-pressed, homogenous mixtures of graphite and silicon carbide powder. Additional argon ion bombardment of the growing film was applied by a substrate bias varied between 0V and -800 V. The deposited amorphous carbon films with two different silicon contents (5 at.% and 23 at.% respectively) were characterised with respect to their microstructure, density, thickness, residual stress, Vickers hardness, Young's modulus, critical load of failure, friction coefficient, and wear behaviour. The residual stress of the carbon films could be remarkably lowered by silicon additions (23 at.%). The hardness reached high values (2200 HV0.05) and the friction coefficient for unlubricated sliding friction against a steel (1.3505) counterpart was as low as 0.06. (Abstract Copyright [2003], Wiley Periodicals, Inc.) [German] Amorphe Kohlenstoffschichten mit Zusaetzen von Silizium wurden nichtreaktiv durch Magnetronzerstaeubung auf Substraten aus WC-Co Hartmetall und Silizium abgeschieden. Die neuartigen Targets wurden durch Heisspressen einer homogenen Mischung aus Graphit- und Siliziumcarbidpulver hergestellt. Durch Anlegen einer elektrischen Substratvorspannung von 0 V bis -800 V wurden die aufwachsenden Schichten zusaetzlich mit Argonionen unterschiedlicher Energie beschossen. Die abgeschiedenen amorphen Kohlenstoffschichten mit Zusaetzen von Silizium (5 at% bzw. 23 at%) wurden hinsichtlich Struktur, Dichte, Dicke, Eigenspannungen, Vickershaerte, reduziertem Elastizitaetsmodul, kritischer Last des Versagens im Ritztest, Reibwert und Verschleissverhalten untersucht. Fuer Schichten mit hohem Siliziumgehalt (23 at%) erfolgte eine erhebliche Reduzierung der Eigenspannung, die Haerte wurde bei sehr hohen Werten stabilisiert (2200 HV0,05) und der Reibungskoeffizient fuer ungeschmierte Gleitreibung gegen Stahl (1

  14. A randomized clinical evaluation of the safety of Systane® Lubricant Eye Drops for the relief of dry eye symptoms following LASIK refractive surgery

    Directory of Open Access Journals (Sweden)

    Daniel Durrie

    2008-12-01

    Full Text Available Daniel Durrie, Jason StahlDurrie Vision, Overland Park, Kansas, USAPurpose: To evaluate the safety of Systane® Lubricant Eye Drops in relieving the symptoms of dry eye following laser-assisted in situ keratomileusis (LASIK surgery.Methods: This was a randomized, double-masked, single-center, placebo-controlled, contralateral eye study of 30 patients undergoing LASIK surgery. The mean age of patients was 42.4 ± 10.7 years, and the mean spherical equivalent was −3.29 (range, +1.75 to −7.38. Patients’ right and left eyes were randomized to receive either Systane® or placebo – a preserved, thimerosal-free saline solution – beginning from the day of surgery and ending 30 days following surgery. Outcome measures included tear film break up time (TFBUT, visual acuity, degree of corneal and conjunctival staining, and treatment-related adverse events.Results: Preoperatively, placebo-treated eyes had statistically significantly higher sum corneal staining score than Systane®-treated eyes (p = 0.0464; however, the difference was clinically insignificant (p = 0.27. Two weeks post operatively, the average TFBUT in the Systane®-treated eyes was 1.23 seconds longer than that of the placebo-treated eyes (p = 0.028. All other evaluated variables were comparable between the two treatments. No adverse events were reported in the study.Conclusion: Systane® Lubricant Eye Drops are safe for use following LASIK surgery to relieve the discomfort symptoms of dry eye associated with the procedure.Keywords: Systane®, safety, dry eye, LASIK

  15. Emerging roles of exosomes in normal and pathological conditions. New insights for diagnosis and therapeutic applications

    Directory of Open Access Journals (Sweden)

    Julieta eDe Toro

    2015-05-01

    Full Text Available From the time when they were first described in the 1970s by the group of Johnstone and Stahl, exosomes are a target of constant research. Exosomes belong to the family of nano-vesicles which are of great interest for their many functions and potential for diagnosis and therapy in multiples diseases. Exosomes originate from the intraluminal vesicles of late endosomal compartments named multivesicular bodies and the fusion of these late endosomes with the cell membrane result in the release of the vesicles into the extracellular compartment. Moreover, their generation can be induced by many factors including extracellular stimuli, such as microbial attack and other stress conditions. The primary role attributed to exosomes was the removal of unnecessary proteins from the cells. Now, several studies have demonstrated that exosomes are involved in cell-cell communication, even though their biological function is not completely clear.The participation of exosomes in cancer is the field of microvesicle research that has expanded more over the last years. Evidence proving that exosomes derived from tumor-pulsed dendritic cells, neoplastic cells and malignant effusions, are able to present antigens to T‐cells, has led to numerous studies using them as cell free cancer vaccines.Since exosomes derive from all cell types, they contain proteins, lipids and miRNA capable of regulating a variety of target genes. Much research is being conducted, which focuses on the employment of these vesicles as biomarkers in the diagnosis of cancer in addition to innovative biomarkers for diagnosis, prognosis and management of cardiovascular diseases. Interesting findings indicating the role of exosomes in the pathogenesis of several diseases have encouraged researchers to consider their therapeutic potential not only in oncology but also in the treatment of autoimmune syndromes and neurodegenerative disorders such as Alzheimer´s and Parkinson´s disease; in addition

  16. Processing and physical utilisation of waste materials relevant to iron and steel manufacture; Aufarbeitung und stoffliche Nutzung eisen- und stahlrelevanter Abfallstoffe

    Energy Technology Data Exchange (ETDEWEB)

    Harp, G.; Schmidt, B.; Sucker, D. [Betriebsforschungsinstitut VDEh-Institut fuer Angewandte Forschung GmbH, Duesseldorf (Germany)

    1998-09-01

    A part of the waste materials arising in iron and steel manufacture is utilised physically, either internally for the recovery of iron or externally for the production of cement and nonferrous metals. Most of these materials can be used without prior processing. Iron and steel-relevant waste materials which at present are still landfilled or disposed of as hazardous wastes are not immediately suitable for physical recycling as secondary raw material. These waste materials have to be processed without exception before they can be used again in the existing steel and iron manufacturing plants. The results of the authors` own studies have clearly shown that the cupola furnace is suited for the use of a wide variety of waste materials. [Deutsch] Ein Teil der bei der Eisen- und Stahlerzeugung anfallenden Abfallstoffe werden entweder intern zur Rueckgewinnung des Eisens oder extern in der Zement- bzw. Nichteisenmetallgewinnung stofflich verwertet. Dabei handelt es sich ueberwiegend um Materialien, die ohne weitere Aufbereitung verwertbar sind. Die bislang noch deponierten oder als Sonderabfall entsorgten eisen- und stahlrelevanten Abfallstoffe sind ohne weiteres als Sekundaerrohstoff nicht stofflich verwertbar. Die Aufarbeitung dieser Abfallstoffe ist fuer den Wiedereinsatz in den vorhandenen Anlagen zur Gewinnung von Eisen und Stahl zwingend erforderlich. Die Ergebnisse der eigenen Untersuchungen haben klar gezeigt, dass der Kupolofen fuer die Nutzung einer grossen Vielfalt an Abfallstoffen geeignet ist. Zur Erhoehung der spezifischen Einsatzmenge an eisen- und stahlrelevanten Abfallstoffen untersuchen wir derzeit den Einsatz von oxidischen Materialien als sogenannte selbstgaengige Briketts zusammen mit den ueblichen Eisentraegern fuer die Erzeugung von fluessigem Giessereieisen. Selbstgaengig heisst hierbei, dass der Reduktionskohlenstoff und auch die notwendigen Legierungselemente insbesondere Silizium als SiC in den Briketts eingebunden werden. Fuer die Aufbereitung

  17. Numeric simulations of a liquid metal model of a bloom caster under the effect of rotary electromagnetic stirring

    Science.gov (United States)

    Barna, M.; Javurek, M.; Willers, B.; Eckert, S.; Reiter, J.

    2016-07-01

    At the voestalpine Stahl Donawitz GmbH the continuous casting of round steel blooms is commonly supported by electromagnetically induced stirring of the liquid steel flow. A number of beneficial effects are attributed to electromagnetic stirring in the mould region (M-EMS), e.g. the enhanced transition from columnar to equiaxed solidification, the homogenization of the liquid steel flow or the reduction of surface and subsurface defects. Although the positive effects of M-EMS can be seen on the blooms (e.g. in etchings), the link between electromagnetic stirring of the steel melt and the quality of the solidified bloom is not sufficiently understood. Theoretical considerations are often limited to general cases and their results are therefore not directly applicable to real continuous casting geometries. On the other hand, plant measurements can only be performed to a limited extent due to the harsh conditions and other restrictions (e.g. safety regulations). In this work an alternative approach is used to investigate the steel flow in a round bloom caster under the influence of M-EMS. In a 1:3 scale Perspex model of a round bloom strand, measurements of the flow under the influence of a rotating magnetic field can be conducted. These measurements provide a validation benchmark for the numeric simulations. A numeric model of the before mentioned 1:3 scale model is implemented, encompassing the strand, the submerged entry nozzle as well as the M-EMS device. In the modelling approach, the bidirectional coupling between liquid steel flow and the electromagnetic field/forces has to be considered because otherwise the resulting tangential velocities will be overestimated. With the validated modelling approach, simulations of real casting machines can then be conducted, stirring parameter influences can be shown and conclusions for the real casting process can be drawn.

  18. Materials flow management in the metal industry. Design and techno-economical analysis of industriyl recycling concepts; Stoffstrommanagement in der Metallindustrie. Zur Gestaltung und techno-oekonomischen Bewertung industrieller Recyclingkonzepte

    Energy Technology Data Exchange (ETDEWEB)

    Haehre, S.

    2000-07-01

    werden das Flow-sheetingssystem Aspen Plus sowie das Oekobilanztool Umberto eingesetzt und exemplarisch Fragen zum Stoffstrommanagement in der Stahl- und der Zinkindustrie untersucht. (orig.)

  19. Deduction and Analysis of the Interacting Stress Response Pathways of Metal/Radionuclide-reducing Bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Jizhong [University of Oklahoma; He, Zhili [University of Oklahoma

    2010-02-28

    Project Title: Deduction and Analysis of the Interacting Stress Response Pathways of Metal/Radionuclide-reducing Bacteria DOE Grant Number: DE-FG02-06ER64205 Principal Investigator: Jizhong (Joe) Zhou (University of Oklahoma) Key members: Zhili He, Aifen Zhou, Christopher Hemme, Joy Van Nostrand, Ye Deng, and Qichao Tu Collaborators: Terry Hazen, Judy Wall, Adam Arkin, Matthew Fields, Aindrila Mukhopadhyay, and David Stahl Summary Three major objectives have been conducted in the Zhou group at the University of Oklahoma (OU): (i) understanding of gene function, regulation, network and evolution of Desulfovibrio vugaris Hildenborough in response to environmental stresses, (ii) development of metagenomics technologies for microbial community analysis, and (iii) functional characterization of microbial communities with metagenomic approaches. In the past a few years, we characterized four CRP/FNR regulators, sequenced ancestor and evolved D. vulgaris strains, and functionally analyzed those mutated genes identified in salt-adapted strains. Also, a new version of GeoChip 4.0 has been developed, which also includes stress response genes (StressChip), and a random matrix theory-based conceptual framework for identifying functional molecular ecological networks has been developed with the high throughput functional gene array hybridization data as well as pyrosequencing data from 16S rRNA genes. In addition, GeoChip and sequencing technologies as well as network analysis approaches have been used to analyze microbial communities from different habitats. Those studies provide a comprehensive understanding of gene function, regulation, network, and evolution in D. vulgaris, and microbial community diversity, composition and structure as well as their linkages with environmental factors and ecosystem functioning, which has resulted in more than 60 publications.

  20. Radiotherapy for tumors of the stomach and gastroesophageal junction – a review of its role in multimodal therapy

    International Nuclear Information System (INIS)

    Buergy, Daniel; Lohr, Frank; Baack, Tobias; Siebenlist, Kerstin; Haneder, Stefan; Michaely, Henrik; Wenz, Frederik; Boda-Heggemann, Judit

    2012-01-01

    There is broad consensus on surgical resection being the backbone of curative therapy of gastric- and gastroesophageal junction carcinoma. Nevertheless, details on therapeutic approaches in addition to surgery, such as chemotherapy, radiotherapy or radiochemotherapy are discussed controversially; especially whether external beam radiotherapy should be applied in addition to chemotherapy and surgery is debated in both entities and differs widely between regions and centers. Early landmark trials such as the Intergroup-0116 and the MAGIC trial must be interpreted in the context of potentially insufficient lymph node resection. Despite shortcomings of both trials, benefits on overall survival by radiochemotherapy and adjuvant chemotherapy were confirmed in populations of D2-resected gastric cancer patients by Asian trials. Recent results on junctional carcinoma patients strongly suggest a survival benefit of neoadjuvant radiochemotherapy in curatively resectable patients. An effect of chemotherapy in the perioperative setting as given in the MAGIC study has been confirmed by the ACCORD07 trial for junctional carcinomas; however both the studies by Stahl et al. and the excellent outcome in the CROSS trial as compared to all other therapeutic approaches indicate a superiority of neoadjuvant radiochemotherapy as compared to perioperative chemotherapy in junctional carcinoma patients. Surgery alone without neoadjuvant or perioperative therapy is considered suboptimal in patients with locally advanced disease. In gastric carcinoma patients, perioperative chemotherapy has not been compared to adjuvant radiochemotherapy in a randomized setting. Nevertheless, the results of the recently published ARTIST trial and the Chinese data by Zhu and coworkers, indicate a superiority of adjuvant radiochemotherapy as compared to adjuvant chemotherapy in terms of disease free survival in Asian patients with advanced gastric carcinoma. The ongoing CRITICS trial is supposed to provide

  1. Grain boundary segregation in FeCrNi model alloys; Korngrenzensegregation in FeCrNi-Modellegierungen

    Energy Technology Data Exchange (ETDEWEB)

    Schlueter, B.; Schneider, F.; Mummert, K. [Institut fuer Festkoerper- und Werkstofforschung Dresden e.V. (Germany); Muraleedharan, P. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Div. of Metallurgy

    1998-12-31

    P and S segregate at the grain boundaries and thus increase susceptibility to intergranular corrosion at those sites. This could be proven by means of nitric acid-chromate tests and potentiostatic etching tests. There is a direct connection between loss in mass, mean depth of intergranular corrosion attacks, dissolution current density, and level of segregation-induced concentration of P and S at the grain boundaries. The segregation effect at these sites was found to be most evident in specimens of the examined Fe-Cr-Ni steel which had been heat-treated for 1000 hours at 550 C. However, segregation occurs also in materials that received a heat treatment of 400 C/5000 hours, while intergranular corrosion is observed only after heat treatment of 500 C/1000 hours. Apart from segregation of P, formation of Cr-rich phosphides is observed, which leads to depletion of Cr at the precipitates. (orig./CB) [Deutsch] P und S segregieren an die KG und erhoehen dort die IK-Anfaelligkeit. Dies konnte mit Hilfe von Salpetersaeure-Chromat- und Potentiostatischem Aetztest nachgewiesen werden. Es besteht ein direkter Zusammenhang zwischen Masseverlust, mittlerer IK-Angriffstiefe, Aufloesungsstromdichte und Hoehe der segregationsbedingten Anreicherungen von P und S an den KG. Der KG-Segregationseffekt am untersuchten Fe-Cr-Ni-Stahl ist im Waermebehandlungszustand 550 C/1000 h am deutlichsten ausgepraegt. Aber auch bereits bei 400 C/5000 h findet Segregation statt. IKSpRK tritt nur im Waermebehandlungszustand 550 C/1000 h auf. Neben der P-Segregation wird die Bildung Cr-reicher Phosphide beobachtet, die zur Abreicherung von Cr an den Ausscheidungen fuehrt. (orig.)

  2. TomoWELD. Precise detection of weld defects; TomoWELD. Defekte in Schweissnaehten praezise erkennen

    Energy Technology Data Exchange (ETDEWEB)

    Walter, David [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany)

    2016-06-15

    Nuclear power plants are complex and technically elaborate systems whose aim is to produce electricity. They must meet the highest safety requirements. Within the reactors, nuclear reactions and radioactive transformations release energy which is used to evaporate water. The steam generated drives turbines that in turn are coupled with generators which convert the kinetic energy provided by the turbines into electrical energy. The process is easy to illustrate but difficult to control and requires technical equipment such as kilometre-long pipe systems. Austenitic steel is frequently used for this purpose because of its high strength and corrosion resistance. The individual pipe components are joined by welding. However, welds may contain hidden defects. Cracks, lack of fusion or pore nests that can remain undetected may have catastrophic consequences. Therefore, all welds in a nuclear power plant, without exception, must be checked. Approved non-destructive methods use ultrasound and X-ray. The technology developed at BAM is called TomoWELD. [German] Kernkraftwerke sind komplexe und technisch aufwendige Anlagen zur Gewinnung von Elektrizitaet. Sie muessen allerhoechsten Sicherheitsanspruechen genuegen. Die bei Kernreaktionen und radioaktiven Umwandlungen freiwerdende Energie wird genutzt, um Wasser zu verdampfen. Der Dampf treibt Turbinen an und die wiederum sind mit Generatoren gekoppelt, welche die durch die Turbinen bereitgestellte kinetische Energie in elektrische Energie umwandeln. Der Prozess laesst sich einfach darstellen, ihn zu steuern ist allerdings kompliziert und erfordert weitere technische Komponenten, wie beispielsweise kilometerlange Rohrleitungssysteme. Wegen seiner hohen Festigkeit sowie Korrosionsbestaendigkeit wird oft austenitischer Stahl dafuer verwendet. Gefuegt werden die einzelnen Rohrteile durch Schweissen. Doch Schweissnaehte koennen viele verborgene Defekte enthalten. Bleiben Risse, Bindefehler oder Porennester unentdeckt, kann das

  3. The angular structure of ONC201, a TRAIL pathway-inducing compound, determines its potent anti-cancer activity.

    Science.gov (United States)

    Wagner, Jessica; Kline, Christina Leah; Pottorf, Richard S; Nallaganchu, Bhaskara Rao; Olson, Gary L; Dicker, David T; Allen, Joshua E; El-Deiry, Wafik S

    2014-12-30

    We previously identified TRAIL-inducing compound 10 (TIC10), also known as NSC350625 or ONC201, from a NCI chemical library screen as a small molecule that has potent anti-tumor efficacy and a benign safety profile in preclinical cancer models. The chemical structure that was originally published by Stahle, et. al. in the patent literature was described as an imidazo[1,2-a]pyrido[4,3-d]pyrimidine derivative. The NCI and others generally accepted this as the correct structure, which was consistent with the mass spectrometry analysis outlined in the publication by Allen et. al. that first reported the molecule's anticancer properties. A recent publication demonstrated that the chemical structure of ONC201 material from the NCI is an angular [3,4-e] isomer of the originally disclosed, linear [4,3-d] structure. Here we confirm by NMR and X-ray structural analysis of the dihydrochloride salt form that the ONC201 material produced by Oncoceutics is the angular [3,4-e] structure and not the linear structure originally depicted in the patent literature and by the NCI. Similarly, in accordance with our biological evaluation, the previously disclosed anti-cancer activity is associated with the angular structure and not the linear isomer. Together these studies confirm that ONC201, produced by Oncoceutics or obtained from the NCI, possesses an angular [3,4-e] structure that represents the highly active anti-cancer compound utilized in prior preclinical studies and now entering clinical trials in advanced cancers.

  4. Bottlenecks in the development of topical analgesics: molecule, formulation, dose-finding, and phase III design

    Directory of Open Access Journals (Sweden)

    Keppel Hesselink JM

    2017-03-01

    Full Text Available Jan M Keppel Hesselink,1 David J Kopsky,2 Stephen M Stahl3 1Institute Neuropathic Pain, Bosch en Duin, the Netherlands; 2Institute Neuropathic Pain, Amsterdam, the Netherlands; 3University of California San Diego, La Jolla, CA, USA Abstract: Topical analgesics can be defined as topical formulations containing analgesics or co-analgesics. Since 2000, interest in such formulations has been on the rise. There are, however, four critical issues in the research and development phases of topical analgesics: 1 The selection of the active pharmaceutical ingredient. Analgesics and co-analgesics differ greatly in their mechanism of action, and it is required to find the most optimal fit between such mechanisms of action and the pathogenesis of the targeted (neuropathic pain. 2 Issues concerning the optimized formulation. For relevant clinical efficacy, specific characteristics for the selected vehicle (eg, cream base or gel base are required, depending on the physicochemical characteristics of the active pharmaceutical ingredient(s to be delivered. 3 Well-designed phase II dose-finding studies are required, and, unfortunately, such trials are missing. In fact, we will demonstrate that underdosing is one of the major hurdles to detect meaningful and statistically relevant clinical effects of topical analgesics. 4 Selection of clinical end points and innovatively designed phase III trials. End point selection can make or break a trial. For instance, to include numbness together with tingling as a composite end point for neuropathic pain seems stretching the therapeutic impact of an analgesic too far. Given the fast onset of action of topical analgesics (usually within 30 minutes, enrichment designs might enhance the chances for success, as the placebo response might decrease. Topical analgesics may become promising inroads for the treatment of neuropathic pain, once sufficient attention is given to these four key aspects. Keywords: topical, analgesics

  5. Forest biomass mapping from fusion of GEDI Lidar data and TanDEM-X InSAR data

    Science.gov (United States)

    Qi, W.; Hancock, S.; Armston, J.; Marselis, S.; Dubayah, R.

    2017-12-01

    Mapping forest above-ground biomass (hereafter biomass) can significantly improve our ability to assess the role of forest in terrestrial carbon budget and to analyze the ecosystem productivity. Global Ecosystem Dynamic Investigation (GEDI) mission will provide the most complete lidar observations of forest vertical structure and has the potential to provide global-scale forest biomass data at 1-km resolution. However, GEDI is intrinsically a sampling mission and will have a between-track spacing of 600 m. An increase in adjacent-swath distance and the presence of cloud cover may also lead to larger gaps between GEDI tracks. In order to provide wall-to-wall forest biomass maps, fusion algorithms of GEDI lidar data and TanDEM-X InSAR data were explored in this study. Relationship between biomass and lidar RH metrics was firstly developed and used to derive biomass values over GEDI tracks which were simulated using airborne lidar data. These GEDI biomass values were then averaged in each 1-km cell to represent the biomass density within that cell. Whereas for cells without any GEDI observations, regression models developed between GEDI-derived biomass and TDX InSAR variables were applied to predict biomass over those places. Based on these procedures, contiguous biomass maps were finally generated at 1-km resolution over three representative forest types. Uncertainties for these biomass maps were also estimated at 1 km following methods developed in Saarela et al. (2016). Our results indicated great potential of GEDI/TDX fusion for large-scale biomass mapping. Saarela, S., Holm, S., Grafstrom, A., Schnell, S., Naesset, E., Gregoire, T.G., Nelson, R.F., & Stahl, G. (2016). Hierarchical model-based inference for forest inventory utilizing three sources of information. Annals of Forest Science, 73, 895-910

  6. Charging Customers or Making Profit? Business Model Change in the Software Industry

    Directory of Open Access Journals (Sweden)

    Margit Malmmose Peyton

    2014-08-01

    Full Text Available Purpose: Advancements in technology, changing customer demands or new market entrants are often seen as a necessary condition to trigger the creation of new Business Models, or disruptive change in existing ones. Yet, the sufficient condition is often determined by pricing and how customers are willing to pay for the technology (Chesbrough and Rosenbloom, 2002. As a consequence, much research on Business Models has focused on innovation and technology management (Rajala et al., 2012; Zott et al., 2011, and software-specific frameworks for Business Models have emerged (Popp, 2011; Rajala et al., 2003; Rajala et al., 2004; Stahl, 2004. This paper attempts to illustrate Business Model change in the software industry. Design: Drawing on Rajala et al. (2003, this case study explores the (1 antecedents and (2 consequences of a Business Model-change in a logistics software company. The company decided to abolish their profitable fee-based licensing for an internet-based version of its core product and to offer it as freeware including unlimited service. Findings: Firstly, we illustrate how external developments in technology and customer demands (pricing, as well as the desire for a sustainable Business Model, have led to this drastic change. Secondly, we initially find that much of the company’s new Business Model is congruent with the company-focused framework of Rajala et al. (2003 [product strategy; distribution model, services and implementation; revenue logic]. Value: The existing frameworks for Business Models in the software industry cannot fully explain the disruptive change in the Business Model. Therefore, we suggest extending the framework by the element of ‘innovation’.

  7. Revisiting Trypanosoma rangeli Transmission Involving Susceptible and Non-Susceptible Hosts.

    Directory of Open Access Journals (Sweden)

    Luciana de Lima Ferreira

    Full Text Available Trypanosoma rangeli infects several triatomine and mammal species in South America. Its transmission is known to occur when a healthy insect feeds on an infected mammal or when an infected insect bites a healthy mammal. In the present study we evaluated the classic way of T. rangeli transmission started by the bite of a single infected triatomine, as well as alternative ways of circulation of this parasite among invertebrate hosts. The number of metacyclic trypomastigotes eliminated from salivary glands during a blood meal was quantified for unfed and recently fed nymphs. The quantification showed that ~50,000 parasites can be liberated during a single blood meal. The transmission of T. rangeli from mice to R. prolixus was evaluated using infections started through the bite of a single infected nymph. The mice that served as the blood source for single infected nymphs showed a high percentage of infection and efficiently transmitted the infection to new insects. Parasites were recovered by xenodiagnosis in insects fed on mice with infections that lasted approximately four months. Hemolymphagy and co-feeding were tested to evaluate insect-insect T. rangeli transmission. T. rangeli was not transmitted during hemolymphagy. However, insects that had co-fed on mice with infected conspecifics exhibited infection rates of approximately 80%. Surprisingly, 16% of the recipient nymphs became infected when pigeons were used as hosts. Our results show that T. rangeli is efficiently transmitted between the evaluated hosts. Not only are the insect-mouse-insect transmission rates high, but parasites can also be transmitted between insects while co-feeding on a living host. We show for the first time that birds can be part of the T. rangeli transmission cycle as we proved that insect-insect transmission is feasible during a co-feeding on these hosts.

  8. New World species of the genus Calliscelio Ashmead (Hymenoptera, Platygastridae, Scelioninae

    Directory of Open Access Journals (Sweden)

    Hua-yan Chen

    2017-01-01

    Full Text Available The genus Calliscelio Ashmead is presumed to be a diverse group of parasitoids of the eggs of crickets (Orthoptera: Gryllidae. A least one species has been found to be an important factor in depressing cricket pest populations. The New World species of Calliscelio are revised. Forty-two species are recognized, 3 are redescribed: C. bisulcatus (Kieffer, C. laticinctus Ashmead, C. rubriclavus (Ashmead, comb. n.; and 38 are described as new: C. absconditum Chen & Johnson, sp. n., C. absum Chen & Johnson, sp. n., C. alcoa Chen & Masner, sp. n., C. amadoi Chen & Johnson, sp. n., C. armila Chen & Masner, sp. n., C. bidens Chen & Masner, sp. n., C. brachys Chen & Johnson, sp. n., C. brevinotaulus Chen & Johnson, sp. n., C. brevitas Chen & Johnson, sp. n., C. carinigena Chen & Johnson, sp. n., C. crater Chen & Johnson, sp. n., C. crena Chen & Johnson, sp. n., C. eboris Chen & Johnson, sp. n., C. extenuatus Chen & Johnson, sp. n., C. flavicauda Chen & Johnson, sp. n., C. foveolatus Chen & Johnson, sp. n., C. gatineau Chen & Johnson, sp. n., C. glaber Chen & Masner, sp. n., C. granulatus Chen & Masner, sp. n., C. latifrons Chen & Johnson, sp. n., C. levis Chen & Johnson, sp. n., C. longius Chen & Johnson, sp. n., C. magnificus Chen & Masner, sp. n., C. migma Chen & Johnson, sp. n., C. minutia Chen & Johnson, sp. n., C. paraglaber Chen & Johnson, sp. n., C. pararemigio Chen & Masner, sp. n., C. prolixus Chen & Johnson, sp. n., C. punctatifrons Chen & Johnson, sp. n., C. remigio Chen & Masner, sp. n., C. ruga Chen & Johnson, sp. n., C. rugicoxa Chen & Masner, sp. n., C. sfina Chen & Johnson, sp. n., C. storea Chen & Johnson, sp. n., C. suni Chen & Johnson, sp. n., C. telum Chen & Johnson, sp. n., C. torqueo Chen & Johnson, sp. n., C. virga Chen & Johnson, sp. n. Four species are treated as junior synonyms of Calliscelio rubriclavus (Ashmead: Anteris nigriceps Ashmead, syn. n., Caloteleia marlattii Ashmead, syn. n., Caloteleia grenadensis Ashmead, syn. n

  9. Detection of Trypanosoma cruzi and Trypanosoma rangeli infection in triatomine vectors by amplification of the histone H2A/SIRE and the sno-RNA-C11 genes Detecção da infecção por Trypanosoma cruzi e Trypanosoma rangeli em vetores triatomíneos através da amplificação dos gens de histona H2A/SIRE e sno-RNA-C11

    Directory of Open Access Journals (Sweden)

    Paula Ximena Pavia

    2007-02-01

    Full Text Available Trypanosoma rangeli is non pathogenic for humans but of important medical and epidemiological interest because it shares vertebrate hosts, insect vectors, reservoirs and geographic areas with T. cruzi, the etiological agent of Chagas disease. Therefore, in this work, we set up two PCR reactions, TcH2AF/R and TrFR2, to distinguish T. cruzi from T. rangeli in mixed infections of vectors based on amplification of the histone H2A/SIRE and the small nucleolar RNA Cl1 genes, respectively. Both PCRs were able to appropriately detect all T. cruzi or T. rangeli experimentally infected-triatomines, as well as the S35/S36 PCR which amplifies the variable region of minicircle kDNA of T. cruzi. In mixed infections, whereas T. cruzi DNA was amplified in 100% of samples with TcH2AF/R and S35/S36 PCRs, T. rangeli was detected in 71% with TrF/R2 and in 6% with S35/S36. In a group of Rhodnius colombiensis collected from Coyaima (Colombia, T. cruzi was identified in 100% with both PCRs and T. rangeli in 14% with TrF/R2 and 10% with S35/S36 PCR. These results show that TcH2AF/R and TrF/R2 PCRs which are capable of recognizing all T. cruzi and T. rangeli strains and lineages could be useful for diagnosis as well as for epidemiological field studies of T. cruzi and T. rangeli vector infections.Embora o Trypanosoma rangeli não seja patogênico para o homem, sua importância médica e epidemiológica reside no fato de compartilhar vetores, reservatórios e áreas geográficas com o Trypanosoma cruzi, agente causal da Doença de Chagas. Neste estudo, para distinguir T. cruzi de T. rangeli em vetores com infecções mistas, se utilizaram duas amplificações de PCR; TcH2AF/R para o gen da histona H2A/SIRE e TrFR2, para um gen repetitivo de ARN nucleolar Cl1 (sno-RNA-Cl1. Assim como a PCR S35/S36, ambas as reações foram capazes de detectar corretamente a presença de T. cruzi ou T. rangeli em triatomíneos infectados experimentalmente. Nas infecções mistas, o ADN de

  10. Estudo anatômico e morfométrico dos folículos testiculares de algumas espécies de Triatominae (Hemiptera: Reduviidae Anatomic and morphometric studies of testicular follicles of some species of Triatominae

    Directory of Open Access Journals (Sweden)

    Teresa Cristina M. Gonçalves

    1987-12-01

    Full Text Available Os folículos testiculares nas ordens dos insetos, vêm demonstrando papel relevante sob o ponto de vista da Sistemática e Filogenia. Nos triatomíneos, os folículos testiculares são em número de sete, sendo que o comprimento e a espesura variam consideravelmente entre os gêneros, e pouco entre as espécies. Verificou-se que em Rhodnius spp existem dois folículos longos e grossos e cinco curtos e fuinnos; em Triatoma spp existem dois longos e finos, dois médios e grossos e três curtos e finos; e em Panstrongylus spp existem sete aproximadamente iguais. Através das medições do comprimento dessas estruturas, evidenciou-se que os valores das médias e desvios padrão das médias, foram muito próximos entre as espécies do mesmo gênero, tornando-se inviável estabelecer limites que pudessem caracterizá-las. Em busca de resultados mais precisos, fizeram-se comparações interespecíficas através da análise de variância: entre as diferentes espécies do mesmo gênro (comparação simultânea; entre cada duas espécies do mesmo gênro (comparação aos pares; e entre espécies iguais de procedência diferentes. Os resultados obtidos não demostraram possibilidades de utilização na Sistemática, contudo foram promissores no que concerne à Filogenia, desde que seja observado um número maior de espécies.The testicular follicle in the varous insect orders, has given evidence of relevance from the point of view of Systematics ans Phylogeny. In the triatomines, the testicular follicles are in number of seven, their lenght and thickness ranging considerabley between the genera and with less variation between the species. It was observed that in Rhodnius spp there exist two long and thick follicles and five short and thin; in Triatoma spp there extist two long and thick, two medium and thick and three short and thin; and in Panstrongylus spp seven, almost identical. Through the measurements of length of these structures, it was observed

  11. Aspectos ecológicos da tripanossomose americana: II - distribuição e dispersão local de triatomíneos em ecótopos naturais e artificiais Ecological aspects of South American tripanosomiasis: II - local distribution and dispersion of triatomids in natural and artificial ecotopes

    Directory of Open Access Journals (Sweden)

    Oswaldo Paulo Forattini

    1971-12-01

    Full Text Available São apresentados os resultados de investigação destinada a estabelecer o quadro de distribuição de Triatoma sordida e Rhodnius neglectus em áreas com ecótopos naturais e artificiais. Essa distribuição revelou-se do tipo agrupado ou contagiante, dirigida uniformemente para casas e anexos por parte do primeiro, e para palmeiras por parte do segundo. Em áreas de vegetação mais densa, do tipo cerrado, a densidade é praticamente nula ou muito baixa, admitindo-se que isso deva correr por conta da competição. As modificações introduzidas pelo homem tendem a anular êsse fator, além de, as suas habitações, se transformarem em ecótopos que atraem a população de T. sordida. Êsse fato, aliado à eliminação local do T. infestans, parece explicar a tendência invasiva daquele triatomíneo. Evidenciou-se também a persistência da infecção pelo Trypanosoma cruzi em triatomíneos e vertebrados domiciliados, o que representa potencial para o incremento da transmissão.A local distribution pattern of Triatoma sordida and Rhodnius neglectus is described after an intensive investigation on natural and artificial ecotopes. The work was carried in a region at north of the State of São Paulo, Brazil. Measures of dispersion pattern were made by the Morisita's indices showing contagious distributions to both bugs. The T. sordida population was clumped at houses and surrounding dwellings, while R. neglectus presented the same aspect but relater to palm trees. The first bug showed ubiquity patter including palms, dry trees and fences. These last two situations are not favourable for obtaining blood meals, who are much more easy obtained at human dwellings. By other side, the investigations at areas with more dense vegetation like bush, resulted in very few T. sordida and none R. neglectus, probably owing of other populations competition as predators reduvids bugs, found there with great density. So it seems logic remove that competition and

  12. Prevalência, índices de infecção e hábitos alimentares de triatomíneos capturados em uma área de vigilância epidemiológica

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    Vera Lúcia C. Corrêa Rodrigues

    1992-09-01

    Full Text Available Em continuação a estudo anterior, relativo à prevalência e infecção por Trypanosoma cruzi dos triatomíneos capturados na região administrativa de Campinas, SP, os autores apresentam dados do período de 1982-1986, acrescentando informações sobre respastos sangüíneos realizados por 7.785 exemplares. Para tanto, foram utilizados os anti-soros: ave, marsupial, roedor e humano, através dos quais constataram o ecletismo alimentar de Panstrongylus megistus, espécie predominante na região, cujas formas aladas são encontradas com freqüência, infectadas por T. cruzi, nas casas habitadas. Desses, 14,78% reagiram frente ao anti-soro humano. Com Rhodnius neglectus foi observada situação assemelhada, mas com números menos expressivos. Em relação ao Triatoma sórdida, não foi constatada infecção natural e tampouco sinais de ingestão de sangue humano. Foi constatado acentuado aumento de T. arthurneivai nas casas, fruto da provável modificação ocorrida no ambiente natural. No período, foi encontrado Microtiatoma borbai, detectado pela primeira vez no Estado de São Paulo. Ressaltam também a importância da "investigação de foco " nas áreas em fase de vigilância.

  13. Aspects of peridomiciliary ecotopes in rural areas of Northeastern Brazil associated to triatomine (Hemiptera, Reduviidae infestation, vectors of Chagas disease

    Directory of Open Access Journals (Sweden)

    Otília Sarquis

    2006-03-01

    Full Text Available Artificial ecotopes of 121 peridomiciliary environments in four rural localities in the state of Ceará, Brazil, were studied and the type of material of the ecotopes was identified as triatomine infestation. Two thousand two hundred and four Triatoma brasiliensis Neiva, 340 Triatoma pseudomaculata Corrêa and Espínola, 121 Rhodnius nasutus Stall, and 5 Panstrongylus lutzi (Neiva and Pinto were captured. Out of the 323 ecotopes found (X =2.0 ± 1.8 per dwelling such as pigpens, henhouses, corrals, perches, dovecotes, piles of roofing tiles, bricks, wood, and straw 30.3% were infested by triatomines in all different developmental stages, including eggs. A substantial number of triatomines were found in perches, however the largest infestation took place in roofing materials used in the construction of goat/sheep corrals, henhouses, and pigpens, where 98% of them were captured: 1372 triatomines were located in the roofing tile covers, 285 in the straw, 187 in the perches, 77 in the coverings of roofing tiles and straw, and 13 in the straw and wood. Among all the different pile of materials, roofing tiles were the most infested (50% followed by bricks (38.9% and woods (36.1%. T. brasiliensis colonized mainly brick piles (chi2=16.539; p < 0.05 and roofing tiles (chi2=5,090.58; p < 0.05; T. pseudomaculata preferred wood perches (chi2= 472.39; p < 0.05 and woodpiles (chi2=126.0 p < 0.05, and R. nasutus was principally found in roofing straw (chi2=384.43; p < 0.05. These findings suggest that triatomines tend to colonize peridomiciliary ecotopes similar to their original habitats.

  14. Trypanosoma cruzi IV causing outbreaks of acute Chagas disease and infections by different haplotypes in the Western Brazilian Amazonia.

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    Wuelton Marcelo Monteiro

    Full Text Available BACKGROUND: Chagas disease is an emergent tropical disease in the Brazilian Amazon Region, with an increasing number of cases in recent decades. In this region, the sylvatic cycle of Trypanosoma cruzi transmission, which constitutes a reservoir of parasites that might be associated with specific molecular, epidemiological and clinical traits, has been little explored. The objective of this work is to genetically characterize stocks of T. cruzi from human cases, triatomines and reservoir mammals in the State of Amazonas, in the Western Brazilian Amazon. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed 96 T. cruzi samples from four municipalities in distant locations of the State of Amazonas. Molecular characterization of isolated parasites from cultures in LIT medium or directly from vectors or whole human blood was performed by PCR of the non-transcribed spacer of the mini-exon and of the 24 S alfa ribosomal RNA gene, RFLP and sequencing of the mitochondrial cytochrome c oxidase subunit II (COII gene, and by sequencing of the glucose-phosphate isomerase gene. The T. cruzi parasites from two outbreaks of acute disease were all typed as TcIV. One of the outbreaks was triggered by several haplotypes of the same DTU. TcIV also occurred in isolated cases and in Rhodnius robustus. Incongruence between mitochondrial and nuclear phylogenies is likely to be indicative of historical genetic exchange events resulting in mitochondrial introgression between TcIII and TcIV DTUs from Western Brazilian Amazon. TcI predominated among triatomines and was the unique DTU infecting marsupials. CONCLUSION/SIGNIFICANCE: DTU TcIV, rarely associated with human Chagas disease in other areas of the Amazon basin, is the major strain responsible for the human infections in the Western Brazilian Amazon, occurring in outbreaks as single or mixed infections by different haplotypes.

  15. Entomological and ecological aspects of six sylvatic species of triatomines (Hemiptera, Reduviidae from the collection of the National Biodiversity Institute of Costa Rica, Central America

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    Rodrigo Zeledón

    2001-08-01

    Full Text Available A total of 797 specimens of wild adult triatomines, belonging to six species from the entomological collections of the Costa Rican National Biodiversity Institute, was studied from the standpoint of their relative abundance, as reflected by light traps, distribution in the country, seasonal variations and climatic and altitudinal preferences. Triatoma dimidiata was the most abundant species (32.9% of the total specimens, with a very extensive distribution in different ecological zones, being more common between 100 to 400 m above sea level mainly at the end of the dry season. T. dispar was the third in frequency (21.5%, with narrower distribution, more abundant between 600 to 800 m and scarce during the dry season. Panstrongylus geniculatus and P. rufotuberculatus, second and fourth in frequency (22.1% and 15.1%, respectively, were widely distributed on both the Pacific and Caribbean basins, the former being more common between 80 to 270 m all year round and the latter below 800 m mainly during the first semester. Eratyrus cuspidatus which represented only 4.9% of the insects, was also present on both basins mainly below 200 m with a tendency to be scarce during certain months of the year, and was found in all types of ecological zones. Finally, Rhodnius pallescens, the least abundant species (3.6% was restricted to very humid areas below 20 m, on the north side and Caribbean basin. With the exception of R. pallescens, males were more commonly found than females. Some epidemiological implications related to the six species are discussed.

  16. Community-Based Entomological Surveillance Reveals Urban Foci of Chagas Disease Vectors in Sobral, State of Ceará, Northeastern Brazil.

    Directory of Open Access Journals (Sweden)

    Cynara Carvalho Parente

    Full Text Available The aim of this work was to explore the potential risk of vector-borne Chagas disease in urban districts in northeastern Brazil, by analyzing the spatiotemporal distributions and natural infection rates with Trypanosoma cruzi of triatomine species captured in recent years. The main motivation of this work was an acute human case of Chagas disease reported in 2008 in the municipality of Sobral.We analyzed data from community-based entomological surveillance carried out from 2010 to 2014. Triatomine natural T. cruzi infection was assessed by examination of insect feces by optical microscopy. Sites of triatomine capture were georeferenced through Google Earth and analyzed with ArcGIS. A total of 191 triatomines were collected, consisting of 82.2% Triatoma pseudomaculata, 7.9% Rhodnius nasutus, 5.8% T. brasiliensis, 3.7% Panstrongylus lutzi, and 0.5% P. megistus, with an overall natural infection index of 17.8%. Most infestations were reported in the districts of Dom José (36.2%, Padre Palhano (24.7%, and Alto do Cristo (10.6%. The overwhelming majority of insects (185/96.9% were captured inside houses, and most insects tended to be collected in intermittent peaks. Moreover, captured triatomines tended to constitute colonies. The acute case reported in 2008 was found to be situated within a T. pseudomaculata hotspot.The triatomine collection events carried out by dwellers were aggregated in time and space into distinct foci, suggesting that insects are intermittently and artificially introduced into the city, possibly via accidental migration from their natural reservoirs. The relatively high T. cruzi infection rate indicates considerable circulation of the parasite in these areas, increasing the risk of vector-borne Chagas disease infection. These data suggest a need to strengthen epidemiological surveillance and integrate appropriate control actions targeting triatomines, T. cruzi reservoirs, and human populations. Our data also identify Chagas

  17. Comprehensive Survey of Domiciliary Triatomine Species Capable of Transmitting Chagas Disease in Southern Ecuador.

    Science.gov (United States)

    Grijalva, Mario J; Villacis, Anita G; Ocaña-Mayorga, Sofia; Yumiseva, Cesar A; Moncayo, Ana L; Baus, Esteban G

    2015-01-01

    Chagas disease is endemic to the southern Andean region of Ecuador, an area with one of the highest poverty rates in the country. However, few studies have looked into the epidemiology, vectors and transmission risks in this region. In this study we describe the triatomine household infestation in Loja province, determine the rate of Trypanosoma cruzi infection in triatomines and study the risk factors associated with infestation. An entomological survey found four triatomine species (Rhodnius ecuadoriensis, Triatoma carrioni, Panstrongylus chinai, and P. rufotuberculatus) infesting domiciles in 68% of the 92 rural communities examined. Nine percent of domiciles were infested, and nymphs were observed in 80% of the infested domiciles. Triatomines were found in all ecological regions below 2,200 masl. We found R. ecuadoriensis (275 to 1948 masl) and T. carrioni (831 to 2242 masl) mostly in bedrooms within the domicile, and they were abundant in chicken coops near the domicile. Established colonies of P. chinai (175 to 2003 masl) and P. rufotuberculatus (404 to 1613 masl) also were found in the domicile. Triatomine infestation was associated with surrogate poverty indicators, such as poor sanitary infrastructure (lack of latrine/toilet [w = 0.95], sewage to environment [w = 1.0]). Vegetation type was a determinant of infestation [w = 1.0] and vector control program insecticide spraying was a protective factor [w = 1.0]. Of the 754 triatomines analyzed, 11% were infected with Trypanosoma cruzi and 2% were infected with T. rangeli. To date, only limited vector control efforts have been implemented. Together with recent reports of widespread sylvatic triatomine infestation and frequent post-intervention reinfestation, these results show that an estimated 100,000 people living in rural areas of southern Ecuador are at high risk for T. cruzi infection. Therefore, there is a need for a systematic, sustained, and monitored vector control intervention that is coupled with

  18. Comprehensive Survey of Domiciliary Triatomine Species Capable of Transmitting Chagas Disease in Southern Ecuador.

    Directory of Open Access Journals (Sweden)

    Mario J Grijalva

    Full Text Available Chagas disease is endemic to the southern Andean region of Ecuador, an area with one of the highest poverty rates in the country. However, few studies have looked into the epidemiology, vectors and transmission risks in this region. In this study we describe the triatomine household infestation in Loja province, determine the rate of Trypanosoma cruzi infection in triatomines and study the risk factors associated with infestation.An entomological survey found four triatomine species (Rhodnius ecuadoriensis, Triatoma carrioni, Panstrongylus chinai, and P. rufotuberculatus infesting domiciles in 68% of the 92 rural communities examined. Nine percent of domiciles were infested, and nymphs were observed in 80% of the infested domiciles. Triatomines were found in all ecological regions below 2,200 masl. We found R. ecuadoriensis (275 to 1948 masl and T. carrioni (831 to 2242 masl mostly in bedrooms within the domicile, and they were abundant in chicken coops near the domicile. Established colonies of P. chinai (175 to 2003 masl and P. rufotuberculatus (404 to 1613 masl also were found in the domicile. Triatomine infestation was associated with surrogate poverty indicators, such as poor sanitary infrastructure (lack of latrine/toilet [w = 0.95], sewage to environment [w = 1.0]. Vegetation type was a determinant of infestation [w = 1.0] and vector control program insecticide spraying was a protective factor [w = 1.0]. Of the 754 triatomines analyzed, 11% were infected with Trypanosoma cruzi and 2% were infected with T. rangeli.To date, only limited vector control efforts have been implemented. Together with recent reports of widespread sylvatic triatomine infestation and frequent post-intervention reinfestation, these results show that an estimated 100,000 people living in rural areas of southern Ecuador are at high risk for T. cruzi infection. Therefore, there is a need for a systematic, sustained, and monitored vector control intervention that is

  19. Comprehensive Survey of Domiciliary Triatomine Species Capable of Transmitting Chagas Disease in Southern Ecuador

    Science.gov (United States)

    Grijalva, Mario J.; Villacis, Anita G.; Ocaña-Mayorga, Sofia; Yumiseva, Cesar A.; Moncayo, Ana L.; Baus, Esteban G.

    2015-01-01

    Background Chagas disease is endemic to the southern Andean region of Ecuador, an area with one of the highest poverty rates in the country. However, few studies have looked into the epidemiology, vectors and transmission risks in this region. In this study we describe the triatomine household infestation in Loja province, determine the rate of Trypanosoma cruzi infection in triatomines and study the risk factors associated with infestation. Methodology/Principal Findings An entomological survey found four triatomine species (Rhodnius ecuadoriensis, Triatoma carrioni, Panstrongylus chinai, and P. rufotuberculatus) infesting domiciles in 68% of the 92 rural communities examined. Nine percent of domiciles were infested, and nymphs were observed in 80% of the infested domiciles. Triatomines were found in all ecological regions below 2,200 masl. We found R. ecuadoriensis (275 to 1948 masl) and T. carrioni (831 to 2242 masl) mostly in bedrooms within the domicile, and they were abundant in chicken coops near the domicile. Established colonies of P. chinai (175 to 2003 masl) and P. rufotuberculatus (404 to 1613 masl) also were found in the domicile. Triatomine infestation was associated with surrogate poverty indicators, such as poor sanitary infrastructure (lack of latrine/toilet [w = 0.95], sewage to environment [w = 1.0]). Vegetation type was a determinant of infestation [w = 1.0] and vector control program insecticide spraying was a protective factor [w = 1.0]. Of the 754 triatomines analyzed, 11% were infected with Trypanosoma cruzi and 2% were infected with T. rangeli. Conclusions/Significance To date, only limited vector control efforts have been implemented. Together with recent reports of widespread sylvatic triatomine infestation and frequent post-intervention reinfestation, these results show that an estimated 100,000 people living in rural areas of southern Ecuador are at high risk for T. cruzi infection. Therefore, there is a need for a systematic, sustained

  20. Dynamics of sylvatic Chagas disease vectors in coastal Ecuador is driven by changes in land cover.

    Directory of Open Access Journals (Sweden)

    Mario J Grijalva

    2014-06-01

    Full Text Available Chagas disease is a serious public health problem in Latin America where about ten million individuals show Trypanosoma cruzi infection. Despite significant success in controlling domiciliated triatomines, sylvatic populations frequently infest houses after insecticide treatment which hampers long term control prospects in vast geographical areas where vectorial transmission is endemic. As a key issue, the spatio-temporal dynamics of sylvatic populations is likely influenced by landscape yet evidence showing this effect is rare. The aim of this work is to examine the role of land cover changes in sylvatic triatomine ecology, based on an exhaustive field survey of pathogens, vectors, hosts, and microhabitat characteristics' dynamics.The study was performed in agricultural landscapes of coastal Ecuador as a study model. Over one year, a spatially-randomized sampling design (490 collection points allowed quantifying triatomine densities in natural, cultivated and domestic habitats. We also assessed infection of the bugs with trypanosomes, documented their microhabitats and potential hosts, and recorded changes in landscape characteristics. In total we collected 886 individuals, mainly represented by nymphal stages of one triatomine species Rhodnius ecuadoriensis. As main results, we found that 1 sylvatic triatomines had very high T. cruzi infection rates (71% and 2 densities of T. cruzi-infected sylvatic triatomines varied predictably over time due to changes in land cover and occurrence of associated rodent hosts.We propose a framework for identifying the factors affecting the yearly distribution of sylvatic T. cruzi vectors. Beyond providing key basic information for the control of human habitat colonization by sylvatic vector populations, our framework highlights the importance of both environmental and sociological factors in shaping the spatio-temporal population dynamics of triatomines. A better understanding of the dynamics of such socio

  1. Expanding the knowledge of the geographic distribution of Trypanosoma cruzi TcII and TcV/TcVI genotypes in the Brazilian Amazon.

    Directory of Open Access Journals (Sweden)

    Valdirene Dos Santos Lima

    Full Text Available Trypanosoma cruzi infection is a complex sylvatic enzooty involving a wide range of animal species. Six discrete typing units (DTUs of T. cruzi, named TcI to TcVI, are currently recognized. One unanswered question concerning the epidemiology of T. cruzi is the distribution pattern of TcII and hybrid DTUs in nature, including their virtual absence in the Brazilian Amazon, the current endemic area of Chagas disease in Brazil. Herein, we characterized biological samples that were collected in previous epizootiological studies carried out in the Amazon Basin in Brazil. We performed T. cruzi genotyping using four polymorphic genes to identify T. cruzi DTUs: mini-exon, 1f8, histone 3 and gp72. This analysis was conducted in the following biological samples: (i two T. cruzi isolates obtained by culturing of stools from the triatomine species Rhodnius picttipes and (ii five serum samples from dogs in which trypomastigotes were observed during fresh blood examination. We report for the first time the presence of TcII and hybrid DTUs (TcV/TcVI in the Amazon region in mixed infections with TcI. Furthermore, sequencing of the constitutive gene, gp72, demonstrated diversity in TcII even within the same forest fragment. These data show that TcII is distributed in the five main Brazilian biomes and is likely more prevalent than currently described. It is very probable that there is no biological or ecological barrier to the transmission and establishment of any DTU in any biome in Brazil.

  2. Stress corrosion crack growth studies on nitrogen added AISI type 316 stainless steel and its weld metal in boiling acidified sodium chloride solution using the fracture mechanics approach

    Energy Technology Data Exchange (ETDEWEB)

    Shaikh, H.; George, G.; Khatak, H.S. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Div. of Metallurgy; Schneider, F.; Mummert, K. [Institut fuer Festkoerper- und Werkstofforschung Dresden e.V. (Germany). Inst. fuer Metallische Werkstoffe

    2000-10-01

    Compact tension specimens of nitrogen-added AISI type 316 austenitic stainless steel and its weld metal were subject to stress corrosion cracking (SCC) testing in a boiling solution containing 5 M sodium chloride + 0.15 M sodium sulphate + 2.5 ml/l hydrochloric acid solution using the constant extension rate testing (CERT) technique. The extension rate of testing was 10 microns per hour. The threshold values of stress intensify factor (K{sub ISCC}) and J-integral (J{sub ISCC}) were taken as those values of K{sub I} and J{sub I} at which about 25 microns of SCC crack growth was observed. These threshold values were about four times higher and plateau crack growth rates (PCGR) were nearly one order of magnitude lower for the base metal vis-a-vis the weld metal. Fractographic observations indicated failure by transgranular SCC (TGSCC) of austenite in both the base and weld metal. No stress-assisted dissolution of delta-ferrite or its interface with austenite, was observed. (orig.) [German] CT-Proben von Grund- und Schweissnahtwerkstoff des stickstoffhaltigen Stahles AISI 316 LN wurden Spannungsrisskorrosionstests in siedender chloridhaltiger Loesung (5 M Natriumchlorid/0,15 M Natriumsulfat/0,03 M Salzsaeure) unterzogen. Die Tests erfolgten bei konstanter Dehnrate (CERT-Test) von 10 {mu}m/h. Als Schwellwerte der Initiierung von Spannungsrisskorrosion K{sub ISCC} und I{sub ISCC} wurden die Werte des Spannungsintensitaetsfaktors K{sub I} und des J-Integrals J{sub I} ermittelt, bei denen ein Risswachstum von 25 {mu}m auftrat. Dabei wies der Grundwerkstoff 4-fach hoehere Schwellwerte K{sub ISCC} und J{sub ISCC} auf als der Schweissnahtwerkstoff. Auch die Risswachstumsraten im Plateaubereich der Risswachstumsrate-Spannungsintensitaetskruven waren am Grundwerkstoff um eine Groessenordnung geringer als am Schweissnahtwerkstoff. Die fraktorgrahischen Untersuchungen zeigten an beiden Materialien Schaedigung durch transkristalline Spannungsrisskorrosion. Eine

  3. Planets and Life

    Science.gov (United States)

    Sullivan, Woodruff T., III; Baross, John

    2007-09-01

    Foreword; Preface; Contributors; Prologue; Part I. History: 1. History of astrobiological ideas W. T. Sullivan and D. Carney; 2. From exobiology to astrobiology S. J. Dick; Part II. The Physical Stage: 3. Formation of Earth-like habitable planets D. E. Brownlee and M. Kress; 4. Planetary atmospheres and life D. Catling and J. F. Kasting; Part III. The Origin of Life on Earth: 5. Does 'life' have a definition? C.E. Cleland and C. F. Chyba; 6. Origin of life: crucial issues R. Shapiro; 7. Origin of proteins and nucleic acids A. Ricardo and S. A. Benner; 8. The roots of metabolism G.D. Cody and J. H. Scott; 9. Origin of cellular life D. W. Deamer; Part IV. Life on Earth: 10. Evolution: a defining feature of life J. A. Baross; 11. Evolution of metabolism and early microbial communities J. A. Leigh, D. A. Stahl and J. T. Staley; 12. The earliest records of life on Earth R. Buick; 13. The origin and diversification of eukaryotes M. L. Sogin, D. J. Patterson and A. McArthur; 14. Limits of carbon life on Earth and elsewhere J. A. Baross, J. Huber and M. Schrenk; 15. Life in ice J. W. Deming and H. Eicken; 16. The evolution and diversification of life S. Awramik and K. J. McNamara; 17. Mass extinctions P. D. Ward; Part V. Potentially Habitable Worlds: 18. Mars B. M. Jakosky, F. Westall and A. Brack; 19. Europa C. F. Chyba and C. B. Phillips; 20. Titan J. I. Lunine and B. Rizk; 21. Extrasolar planets P. Butler; Part VI. Searching for Extraterrestrial Life: 22. How to search for life on other worlds C. P. McKay; 23. Instruments and strategies for detecting extraterrestrial life P. G. Conrad; 24. Societial and ethical concerns M. S. Race; 25. Planetary protection J. D. Rummel; 26. Searching for extraterrestrial intelligence J. C. Tarter; 27. Alien biochemistries P. D. Ward and S. A. Benner; Part VII. Future of the Field: 28. Disciplinary and educational opportunities L. Wells, J. Armstrong and J. Huber; Epilogue C. F. Chyba; Appendixes: A. Units and usages; B. Planetary

  4. Corrosion behavior of selected materials in lithium bromide solution for the application absorption chillers; Korrosionsverhalten ausgewaehlter Werkstoffe in Lithiumbromid-Loesung fuer den Anwendungsfall Absorptionskaeltemaschinen

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, B. [ZAE Bayern, Garching (Germany)

    2004-07-01

    Beanspruchung der Werkstoffe. Aufgabe des vorliegenden Beitrages war deshalb die Betrachtung handelsueblicher Werkstoffe und Inhibitoren auf ihre Eignung fuer Triple-Effekt-Absorptionskaeltemaschinen. Die Messungen wurden unter analogen Bedingungen in ruhender Loesung unter nahezu vollstaendigem Ausschluss von Luft durchgefuehrt. Die Untersuchungen haben ergeben, dass nichtrostender Stahl hinsichtlich seiner Materialstabilitaet besonders aussichtsreich ist. Weiterhin hat sich gezeigt, dass die Art des Inhibitors und das Zusammenwirken unterschiedlicher Phasen die Korrosion erheblich beeinflussen koennen. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

  5. Demolition of the FRJ-1 research reactor (MERLIN); Abbau des Reaktorblocks des Forschungsreaktors FRJ-1 (MERLIN)

    Energy Technology Data Exchange (ETDEWEB)

    Stahn, B.; Matela, K.; Zehbe, C. [Forschungszentrum Juelich GmbH (Germany); Poeppinghaus, J. [Gesellschaft fuer Nuklearservice, Essen (Germany); Cremer, J. [SNT Siempelkamp Nukleartechnik, Heidelberg (Germany)

    2003-06-01

    Reaktortankeinbauten einschliesslich des Ablassens des Reaktortankwassers. Im Anschluss wurde nach erteilter Genehmigung durch die zustaendige Behoerde im Oktober 2001 mit dem Abbau des Reaktorblocks, der zentralen Einrichtung des Forschungsreaktors, begonnen. In einem ersten Schritt wurden Reaktorbuehne und Reaktoranbauten durch das mit der Gesamtplanung und -durchfuehrung beauftragte Konsortium GNS/SNT entfernt. Dabei fielen ca. 50 Mg Schwerbeton und ca. 25 Mg Stahl an. Der Abbau des eigentlichen Reaktorblocks erfolgt in mehreren Teilschritten. Zum Einsatz kommen verschiedenste bewaehrte Trennverfahren. Es werden rund 170 Mg radioaktiver Abfaelle mit einer Gesamtaktivitaet von ca. 3,5.10{sup 11} Bq anfallen. Eine installierte Freimessanlage gewaehrleistet eine effektive und sichere radiologische Bewertung der anfallenden Abbaukomponenten, von denen ca. 750 Mg freigegeben werden koennen. Im 1. Halbjahr 2003 soll der Abbau des Reaktorblocks abgeschlossen werden. (orig.)

  6. Microstructure, state of internal stress and corrosion resistance of the short-time laser heat-treated nitrogen high-alloyed tool steel X30CrMoN151; Mikrostruktur, Eigenspannungszustand und Korrosionsbestaendigkeit des kurzzeitlaserwaermebehandelten hochstickstofflegierten Werkzeugstahls X30CrMoN151

    Energy Technology Data Exchange (ETDEWEB)

    Bohne, C. (ed.)

    2000-07-01

    This study compares the crystalline structure, state of internal stress and chemical properties of the high-alloyed nitrogen tool steel X30CrMoN15 1 and conventional cold work steel X39CrMo17 1. Transformation points A{sub c}1b and A{sub c}1e were calculated from residual austenite analysis and the c{sub m}/a{sub m} martensite ratios for various heating rates. This was used to generate a TTA (time-temperature-austenitisation) graph for X30CrMoN15 1 for the first time. Transmission electron microscopy and small-angle neutron scattering show that precipitates in nitrogen high-alloyed steel X30CrMoN15 1 can be eliminated completely by short-time laser heat treatment. The corrosion tests show that in contrast to X39CrMo17 1 X30CrMoN15 1 reacts more sensitively to parameter changes during short-time heat treatment in oxidising acid at pH 5-6. [German] Im Rahmen der Arbeit werden die Gefuegeausbildung, Eigenspannungen und chemische Eigenschaften des hochstickstofflegierten Werkzeugstahls X30CrMoN15 1 und des konventionellen Kaltarbeitsstahls X39CrMo17 1 verglichen. Aus den Restaustenitanalysen und den c{sub m}/a{sub m}-Verhaeltnissen des Martensits konnten die Umwandlungspunkte A{sub c1b} und A{sub c1e} fuer verschiedene Aufheizraten bestimmt und daraus ein bisher nicht bekanntes ZTA-Schaubild fuer den X30CrMoN15 1 erstellt werden. Transmissionselektronenmikroskopie und Neutronenkleinwinkelstreuung zeigen, dass sich die Ausscheidungen im hochstickstofflegierten Stahl X30CrMoN14 1 durch die Kurzzeitlaserwaermebehandlung vollstaendig aufloesen koennen. Die Korrosionsversuche zeigen, dass im Gegensatz zum X39CrMo17 1 der X30CrMoN15 1 in oxidierender Saeure bei pH 5-6 empfindlicher auf Parameteraenderungen bei der Kurzzeitwaermebehandlung reagiert. (orig.)

  7. Experimental and numerical analysis of the static and dynamic crack growth resistance behaviour of structural steels in the temperature range from 20 C to 350 C; Experimentelle und numerische Untersuchungen des statischen und dynamischen Risswiderstandsverhaltens verschiedener hoeherfester Baustaehle im Temperaturbereich von 20 C bis 350 C

    Energy Technology Data Exchange (ETDEWEB)

    Aurich, D.; Gerwien, P.; Huenecke, J.; Klingbeil, D.; Krafka, H.; Kuenecke, G.; Ohm, K.; Veith, H.; Wossidlo, P. [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany); Haecker, R.; 1

    1998-11-01

    The crack growth resistance behaviour of the steels StE 460 and 22NiMoCr3-7 was determined in the temperature range from 23 C to 350 C by means of C(T), M(T), and ISO-V specimens tested under quasistatic and dynamic loads. The Russian steel 15Ch2NMFA-A was tested at room temperature and 50 C. In the steels StE 460 and 22 NiMoCr3-7, the minimum crack growth resistance is observed at about 250 C, with measured values always being higher for the latter steel type. The crack growth resistance behaviour of the tested materials correlates with the behaviour of flow curve, yield strength, and notch impact toughness as a function of temperature. Impact tests of ISO-V specimens give higher crack resistance values than quasistatic load tests, and the temperature dependence is significantly lower than those of specimens tested under static loads. A metallurgical analysis of the materials shows the causes of the dissimilar behaviour. The stretching zones determined for the C(T) specimen correspond to the toughness of the steels examined, and they are not much influenced by the temperature. The numerical analysis using damaging models for simulation of ductile crack growth is reported for all specimen types and two different temperatures each. (orig./CB) [Deutsch] Mit C(T)-, M(T)- sowie quasistatisch und dynamisch geprueften ISO-V-Proben wurde das Risswiderstandsverhalten fuer die Staehle StE 460 und 22NiMoCr3-7 im Temperaturbereich von 23 C bis 350 C ermittelt, waehrend der russische Stahl 15Ch2NMFA-A fuer Raumtemperatur und fuer 50 C untersucht wurde. Das Minimum der Risszaehigkeit stellt sich bei StE 460 und 22 NiMoCr3-7 um etwa 250 C ein, wobei die Werte fuer den 22NiMoCr3-7 bei allen Temperaturen wesentlich hoeher liegen als beim StE 460. Dabei korreliert das Risswiderstandsverhalten der untersuchten Werkstoffe mit dem Verhalten von Fliesskurven, Streckgrenzen und Kerbschlagzaehigkeiten in Abhaengigkeit von der Temperatur. Schlagartig beanspruchte ISO-V-Proben liefern

  8. The EASTNET Project: Extending the Network of Climate-Sensitive Tree-Ring Chronologies From the Eastern United States for Reconstructing the Spatio-Temporal Characteristics of Climate and Drought Over the Past Millennium

    Science.gov (United States)

    Buckley, B. M.; Cook, E. R.

    2002-12-01

    of Medieval Warm Period (MWP) and Little Ice Age (LIA) type signatures from an eastern red cedar chronology from West Virginia that spans the past 1,500 years. This is the oldest chronology so far developed from this project, though we anticipate the development of several more millennial length time-series within the next year. References Cook, E.R., Meko, D.M., Stahle, D.W., and Cleaveland, M.K. 1999. Drought reconstructions for the continental United States. Journal of Climate 12:1145-1162.

  9. Influence of S, P, C on grain boundary diffusion and creep properties of Alloy 800; Einfluss von S, P, C auf die Korngrenzendiffusion und Kriecheigenschaften von Alloy 800

    Energy Technology Data Exchange (ETDEWEB)

    Lindemann, J.; Hannesen, K.; Mast, R.; Viefhaus, H. [Max-Planck-Institut fuer Eisenforschung GmbH, Duesseldorf (Germany); Grabke, H.J.

    1998-12-31

    The paper reports examinations of Alloy 800 and specific commercially available variants known under the names of 800H, 800HT, and 800LC, differing in their concentrations of C, Al, and Ti. In addition, melts also containing phosphorus (0.09 wt-%) or sulfur (0.04 wt-%) as additional alloying materials have been prepared for the experiments. The volume diffusion and the grain boundary diffusion of {sup 59}Fe in those alloys was measured at temperatures between 800 and 1000 C by means of a radioactive tracer method combined with residual activity measurements. It was found that accompanying elements like phosphorus and sulfur increase the activation energy of the grain boundary diffusion of the iron and thus delay the grain boundary self-diffusion in Alloy 800. Creep curves were measured of the same materials after age-hardening treatment for 100 hours at 800 C, measurements performed at constant temperature but at three different, constant creep stress loads. The results showed that addition of phosphorus markedly increases the lifetime of Alloy 800, and reduces the creep rupture strain. The minimum strain rate in Alloy 800 containing 0.09 wt-% of phosphorus was found to be lower by a factor of 100, as compared to the other Alloy 800 materials used. (orig./CB) [Deutsch] Alloy 800 ist ein austenitischer Fe-Ni-Cr Stahl, der relativ geringe, aber wichtige Konzentrationen von Kohlenstoff, Aluminium und Titan enthaelt. Besondere Varianten von Alloy 800, bekannt als 800H, 800HT und 800LC, unterscheiden sich in den Konzentrationen dieser Elemente. Diese kommerziellen Legierungen wurden untersucht, und zusaetzlich wurden Schmelzen mit zulegiertem Phosphor (0,09 Gew-%) bzw. Schwefel (0,04 Gew-%) hergestellt. Mittels einer radioaktiven Tracermethode in Verbindung mit Restaktivitaetsmessungen wurde die Volumen- und Korngrenzendiffusion von {sup 59}Fe in diesen Legierungen im Temperaturbereich 800-1000 C gemessen. Es wurde gefunden, dass Begleitelemente wie Phosphor und

  10. The effect of local/topical analgesics on incisional pain in a pig model

    Directory of Open Access Journals (Sweden)

    Castel D

    2017-09-01

    Full Text Available David Castel,1 Itai Sabbag,2 Sigal Meilin3 1The Neufeld Cardiac Research Institute, Sheba Medical Centre, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, 2Lahav Research Institute, Kibutz Lahav, Negev, 3Neurology R&D Division, MD Biosciences, Nes-Ziona, Israel Abstract: Interest in the development of new topical/local drug administration for blocking pain at peripheral sites, with maximum drug activity and minimal systemic effects, is on the rise. In the review article by Kopsky and Stahl, four critical barriers in the process of research and development of topical analgesics were indicated. The active pharmaceutical ingredient (API and the formulation are among the major challenges. The road to the development of such drugs passes through preclinical studies. These studies, if planned correctly, should serve as guidance for choosing the right API and formulation. Although rodent models for pain continue to provide valuable data on the mechanisms driving pain, their use in developing topical and localized treatment approaches is limited for technical (intraplate injection area is small as well as mechanical reasons (non-similarity to human skin and innervation. It has been previously shown that pigs are comparable to humans in ways that make them a better choice for evaluating topical and local analgesics. The aim of this study was to summarize several experiments that used pigs for testing postoperative pain in an incisional pain model (skin incision [SI] and skin and muscle incision [SMI]. At the end of the surgery, the animals were treated with different doses of bupivacaine solution (Marcaine®, bupivacaine liposomal formulation (Exparel® or ropivacaine solution (Naropin. Von Frey testing demonstrated a decrease in the animals’ sensitivity to mechanical stimulation expressed as an increase in the withdrawal force following local treatment. These changes reflect the clinical condition in the level as well as in the duration of

  11. A framework for quantification of groundwater dynamics - redundancy and transferability of hydro(geo-)logical metrics

    Science.gov (United States)

    Heudorfer, Benedikt; Haaf, Ezra; Barthel, Roland; Stahl, Kerstin

    2017-04-01

    , which are readily available for usage in studies on groundwater dynamics, intended to help overcome analytical limitations that exist due to the complexity of groundwater dynamics. Haaf, E., Heudorfer, B., Stahl, K., Barthel, R., 2017. A framework for quantification of groundwater dynamics - concepts and hydro(geo-)logical metrics. EGU General Assembly 2017, Vienna, Austria.

  12. A framework for quantification of groundwater dynamics - concepts and hydro(geo-)logical metrics

    Science.gov (United States)

    Haaf, Ezra; Heudorfer, Benedikt; Stahl, Kerstin; Barthel, Roland

    2017-04-01

    similarity classification framework for groundwater hydrographs. However, the overabundance of metrics available calls for a systematic redundancy analysis of the metrics, which we describe in a second study (Heudorfer et al., 2017). Heudorfer, B., Haaf, E., Barthel, R., Stahl, K., 2017. A framework for quantification of groundwater dynamics - redundancy and transferability of hydro(geo-)logical metrics. EGU General Assembly 2017, Vienna, Austria.

  13. A new endemic focus of Chagas disease in the northern region of Veraguas Province, Western Half Panama, Central America.

    Directory of Open Access Journals (Sweden)

    Azael Saldaña

    Full Text Available BACKGROUND: Chagas disease was originally reported in Panama in 1931. Currently, the best knowledge of this zoonosis is restricted to studies done in historically endemic regions. However, little is known about the distribution and epidemiology of Chagas disease in other rural areas of the country. METHODS AND FINDINGS: A cross-sectional descriptive study was carried out between May 2005 - July 2008 in four rural communities of the Santa Fe District, Veraguas Province. The study included an entomologic search to collect triatomines, bloodmeal type identification and infection rate with trypanosomes in collected vectors using a dot- blot and PCR analysis, genotyping of circulating Trypanosoma cruzi (mini-exon gene PCR analysis and the detection of chagasic antibodies among inhabitants. The vector Rhodnius pallescens was more frequently found in La Culaca and El Pantano communities (788 specimens, where it was a sporadic household visitor. These triatomines presented darker coloration and larger sizescompared with typical specimens collected in Central Panama. Triatoma dimidiata was more common in Sabaneta de El Macho (162 specimens. In one small sub-region (El Macho, 60% of the houses were colonized by this vector. Of the examined R. pallescens, 54.7.0% (88/161 had fed on Didelphis marsupialis, and 24.6% (34/138 of T. dimidiata specimens collected inside houses were positive for human blood. R. pallescens presented an infection index with T. cruzi of 17.7% (24/136, with T. rangeli of 12.5% (17/136 and 50.7% (69/136 were mixed infections. In 117 T. dimidiata domestic specimens the infection index with T. cruzi was 21.4%. Lineage I of T. cruzi was confirmed circulating in these vectors. A T. cruzi infection seroprevalence of 2.3% (24/1,056 was found in this population. CONCLUSIONS: This is the first report of Chagas disease endemicity in Santa Fe District, and it should be considered a neglected public health problem in this area of Panama.

  14. Parasitismo natural de ovos de triatomíneos por Telenomus fariai lima, 1927 no laboratório

    Directory of Open Access Journals (Sweden)

    Alexandre José Fernandes

    1990-09-01

    Full Text Available Em novembro/89 verificou-se que o insetário do Centro de Estudos Emmanuel Dias - Bambuí/MG apresentava alta infestação pelo micro himenóptero Telenomus fariai. Em 529 ovos de Panstrongylus megistus e Triatoma vitticeps examinados, 375 (70,9% apresentavam 1043 exemplares de T. fariai, sendo 955 (91,4% fêmeas e 90 (8,6% machos. A seguir, verificou-se também oparasitismo de ovos de Triatoma infestans, e ausência de infestação de ovos de Rhodnius neglectus. As médias de parasitóide por ovo observadas foram de 7,9 em P. megistus; 8,7 em T. vitticeps e 10 em T. infestans. A importância do relato deve-se à possibilidade da infestação de colônias mantidas para fins de pesquisa a partir da introdução em insetários de ovos procedentes do campo, com o estabelecimento de altas taxas de infestação e acentuado declínio da criação. O isolamento e a eliminação dos parasitóides pelo manejo dos ovos parasitados e vedação dos frascos do insetário com tecido de malha estreita (em tomo de 0,25mm mostraram-se eficientes no controle do T. fariai.In november/89 in the insectary of Centro de Estudos "Emmanuel Dias"/Bambui-MG a high infestation by the microhymenoptera T. fariai was found. Among the 529 eggs examined from P. megistus and T. vitticeps, 375(70.9% of them showed a total of1045parasites (91.4% females and 8.6% males. Later on it was found that T. infestans eggs were also parasitised by T. fariai but not those from R. neglectus. The observedparasitoid/egg average was 7.9 in P. megistus; 8.7 in T. vitticeps and 10 in T. infestans. The present report has special importance considering the real possibility ofT. fariai infestation due to the access of infested triatomine eggs from field captures inducing great damage to colonies maintainedfor research purposes. These eggs have to be carefully examined, isolated and eliminated. This procedure and the closing of triatomine containers with thin net (0.25 mm is show to be efficient in T

  15. Infestation of Palm Trees by Triatomines (Hemiptera: Reduviidae in the State of Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Rodrigo Gurgel-Gonçalves

    2012-12-01

    Resumo. As palmeiras desempenham papéis importantes como habitats de reprodução e alimentação para triatomíneos silvestres, vetores da doença de Chagas. A ocorrência de triatomíneos em palmeiras peridomiciliares pode aumentar o risco de invasão desses insetos em domicílios e deve ser considerada para desenvolver estratégias de prevenção. Com objetivo de investigar a infestação de palmeiras por triatomíneos no Estado da Bahia e determinar a infecção natural desses insetos por Trypanosoma spp., foram amostradas 183 palmeiras em 12 municípios entre 2006 e 2011 utilizando captura manual e/ou armadilhas adesivas iscadas com camundongos. Os triatomíneos foram detectados em 79 palmeiras (43% das espécies Copernicia prunifera (Mart. Becc., Mauritia flexuosa L. e Attalea spp. (Attalea burretiana Bondar ou Attalea salvadorensis Glassman. Em outras espécies de palmeiras (Syagrus coronata (Mill H.E. Moore, Attalea funifera Mart ex. Spreng e Elaeis guineensis Jacq não foram detectados triatomíneos. Rhodnius neglectus Lent, Triatoma sordida (Stål, e Triatoma pseudomaculata Corrêa & Espínola ocorreram em C. prunifera ao longo do rio São Francisco. No extremo oeste da Bahia, R. neglectus e Psammolestes tertius Lent & Jurberg foram detectados em M. flexuosa, enquanto Triatoma tibiamaculata (Pinto ocorreu em Attalea sp. em áreas urbanas de Salvador. No total, 180 triatomíneos foram capturados, principalmente R. neglectus. A maior taxa de infecção natural (61% foi observada em T. tibiamaculata. Os resultados indicam que pelo menos três espécies de palmeiras são habitats favoráveis para triatomíneos no estado da Bahia e ocorrem no ambiente peridomiciliar, o que pode aumentar a probabilidade de invasão de triatomíneos nas casas.

  16. Enfermedad de chagas en la Región Nororiental del Perú. I. Triatominos (Hemiptera, Reduviidae presentes en Cajamarca y Amazonas

    Directory of Open Access Journals (Sweden)

    Abraham G Cáceres

    2002-01-01

    Full Text Available Objetivos: Conocer la diversidad de triatominos presentes en las provincias de San Ignacio y Jaén (Cajamarca y en Bagua, Condorcanqui y Utcubamba (Amazonas. Materiales y métodos: los triatominos fueron capturados de mayo 1995 a diciembre 2000 en el intra y peridomicilios de las viviendas de las provincias de San Ignacio (5 distritos y Jaén (10 distritos del departamento de Cajamarca, y en 5 distritos de Bagua, un distrito de Condorcanqui y en seis de Utcubamba (Amazonas. El muestreo fue de 08:00 a 19:00 horas con alambre de 30 cm de largo, pinzas largas y linterna de mano. Resultados: se capturaron 5567 triatominos pertenecientes a cinco especies. Panstrongylus herreri fue la especie más predominante (94%. 90% del total de triatominos fueron capturados en ambientes intradomiciliarios. Se reporta Rhodnius robustus por primera vez para Amazonas. Ejemplares de R. ecuadoriensis y R. robustus, fueron colectados en intradomicilios en porcentajes mínimos en Sallique, provincia de Jaén (Cajamarca y Nieva, provincia de Condorcanqui (Amazonas. Panstrongylus geniculatus fue colectado en intradomicilios. Se reporta en ciertas localidades de La Coipa, Huarango y Namballe (San Ignacio; así como en Bellavista y Santa Rosa (Jaén y en Aramango, Copallín e Imaza (Bagua; además, en Jamalca, Cajaruro y Bagua Grande (Utcubamba. Panstrongylus chinai, especie silvestre con tendencia a domesticarse, se encontró en Santa Rosa, Bellavista, Chontalí y San José del Alto (Jaén y en Namballe, San Ignacio, La Coipa y Chirinos (San Ignacio. También se encontró en Cajaruro y Bagua Grande (Utcubamba. 90% de P. herreri fueron colectados en el interior de las viviendas. Para Cajamarca se ha colectado en Pomahuaca, Pucará, San José del Alto, Pirias, Bellavista, Santa Rosa, La Coipa y Huarango; mientras que para Amazonas en Aramango, Parco, Bagua Grande, Cajaruro y El Milagro.

  17. Triatominae-Trypanosoma cruzi/T. rangeli: Vector-parasite interactions.

    Science.gov (United States)

    Vallejo, G A; Guhl, F; Schaub, G A

    2009-01-01

    subpathogenic for the insect host, T. rangeli strongly affects species of the genus Rhodnius and this pathogenicity seems based on a reduction of the number of symbionts.

  18. Book Reviews

    Directory of Open Access Journals (Sweden)

    Christine Oppong

    1977-01-01

    Full Text Available - P. van de Velde, Chester G. Starr, Early man - Prehistory and the civilizations of the ancient near east. New York, London, Toronto, Oxford University Press, 1973. 7 + 205 pp., num. ill. black and white colour. - H. Hoetink, Ashley Montagu, Man’s most dangerous myth: the fallacy of race. New York, Oxford University Press, 1974, 5th edition, 542 pp. - J. Tennekes, Margaret T. Hodgen, Anthropology, history and cultural change. Viking Fund Publications in Anthropology, number 52. The University of Arizona Press, pp. 108, 1974. - H.J.M. Claessen, Regna Darnell, Readings in the history of anthropology. New York etc., Harper & Row, 1974. 479 pp. - John Beattie, F. Allan Hanson, Meaning in culture. London and Boston: Routledge & Kegan Paul (International Library of Anthropology, 1975. xi, 127 pp., bibl. - J. van Baal, Dan Sperber, Le symbolisme en général. Collection Savoir, Hermann, Paris, 1974. 163 pp. - David S. Moyer, Claude Levi-Strauss, La Voie des Masques. Les Sentiers de la Création, Editions d’art Albert Skira, Genève, 1975. Vol I, 142 pp. and vol. II, 147 pp. Figs., maps, colour plates. - W.C. Ultee, Suzanne Petra Schad, Empirical social research in Weimar-Germany. Mouton, Paris-The Hague, 1972. 155 pp. - C.J.J. Vermeulen, Paul-Henry Stahl, Ethnologie de l’Europe du Sud-est. Une anthologie. Mouton Éditeur, Paris/La Haye 1974. 312 p. - C.J.J. Vermeulen, Juliet du Boulay, Portrait of a Greek mountain village. Oxford monographs on social anthropology. Clarendon Press, Oxford 1974. viii, 296 pp., photogr. - Lodewijk Brunt, Jacob Black-Michaud, Cohesive force. Fued in the Mediterranean andthe Middle East. Oxford: Basil Blackwell 1975. With a foreword by E.L. Peters. 270 pp. - J.H. van den Brink, D’arcy McNickle, Native American Tribalism - Indian survivals and renewals. Oxford University Press, New York, London, 1973. 190 pp., geïll. - Sjaak van der Geest, Christine Oppong, Marriage among a matrilineal elite. A family

  19. A Revised Set of Dendroclimatic Reconstructions of Summer Drought over the Conterminous U.S.

    Science.gov (United States)

    Zhang, Z.; Mann, M. E.; Cook, E. R.

    2002-12-01

    We describe a revised set of dendroclimatic reconstructions of drought patterns over the conterminous U.S back to 1700. These reconstructions are based on a set of 483 drought-sensitive tree ring chronologies available across the continental U.S. used previously by Cook et al [Cook, E.R., D.M. Meko, D.W. Stahle, and M.K. Cleaveland, Drought Reconstructions for the Continental United States, Journal of Climate, 12, 1145-1162, 1999]. In contrast with the "Point by Point" (PPR) local regression technique used by Cook et al (1999), the tree ring data were calibrated against the instrumental record of summer drought[June-August Palmer Drought Severity Index (PDSI)] based on application of the "Regularized Expectation Maximization" (RegEM) algorithm to relate proxy and instrumental data over a common (20th century) interval. This approach calibrates the proxy data set against the instrumental record by treating the reconstruction as initially missing data in the combined proxy/instrumental data matrix, and optimally estimating the mean and covariances of the combined data matrix through an iterative procedure which yields a reconstruction of the PDSI field with minimal error variance [Schneider, T., Analysis of Incomplete Climate Data: Estimation of Mean Values and Covariance Matrices and Imputation of Missing Values, Journal of Climate, 14, 853-871, 2001; Mann, M.E., Rutherford, S., Climate Reconstruction Using 'Pseudoproxies', Geophysical Research Letters, 29, 139-1-139-4, 2002; Rutherford, S., Mann, M.E., Delworth, T.L., Stouffer, R., The Performance of Covariance-Based Methods of Climate Field Reconstruction Under Stationary and Nonstationary Forcing, J. Climate, accepted, 2002]. As in Cook et al (1999), a screening procedure was first used to select an optimal subset of candidate tree-ring drought predictors, and the predictors (tree ring data) and predictand (instrumental PDSI) were pre-whitened prior to calibration (with serial correlation added back into the

  20. Substitution of wastes for fuels and raw materials in high-temperature processes; Substitution von Brennstoffen und Rohstoffen durch Abfaelle in Hochtemperaturprozessen

    Energy Technology Data Exchange (ETDEWEB)

    Scholz, R. [Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany). Inst. fuer Energieverfahrenstechnik; Beckmann, M. [Clausthaler Umwelttechnik-Institut GmbH (CUTEC), Clausthal-Zellerfeld (Germany)

    1998-09-01

    Brennstoffsubstitution ist das sogenannte Energieaustauschverhaeltnis. Dieses Verhaeltnis drueckt die Wertigkeit eines Ersatzbrennstoffes im Vergleich zu dem Primaerbrennstoff aus und muss bei einer vergleichenden Bilanzierung entsprechend beruecksichtigt werden. Weiter werden in dem Beitrag beispielhaft fuer den Klinkerbrennprozess in der Zementindustrie verschiedene Auswirkungen der Brennstoffsubstitution z.B. auf Ofentemperaturen, Abgasmengenstroeme usw. aus verfahrenstechnischer Sicht angesprochen. Aus dem Bereich der Stahl- und Eisenindustrie wird auf die Brennstoffsubstitution bei einem erdgasbefeuerten, kokslosen Kupolofen eingegangen. (orig.)

  1. Characterization of graded iron / tungsten layers for the first wall of fusion reactors; Charakterisierung gradierter Eisen/Wolfram-Schichten fuer die erste Wand von Fusionsreaktoren

    Energy Technology Data Exchange (ETDEWEB)

    Heuer, Simon

    2017-07-01

    Energiequelle bislang eine Herausforderung dar. Insbesondere fuehren hohe thermische Lasten und Neutronen-induzierte Schaedigung zu extremen Anforderungen an die Materialauswahl fuer Plasma-zugewandte Komponenten (PFCs). Diese sind daher nach derzeitigem Verstaendnis aus einer Wolfram-Schutzschicht, welche an eine Struktur aus niedrig aktivierbarem ferritisch-martensitischen (RAFM) Stahl gefuegt wird, zu fertigen. Aufgrund des diskreten Uebergangs von Materialeigenschaften an der RAFM-W-Fuegezone sowie thermischer Lasten, entstehen hier makroskopische Spannungen und plastische Dehnungen. Ein gangbarer Weg, diese zu reduzieren, stellt die Implementierung einer Zwischenschicht mit gradiertem RAFM/W-Verhaeltnis, einem s.g. funktional gradiertem Material (FGM), in der Fuegezone dar. In der vorliegenden Arbeit werden Makrospannungen und -dehnungen in der ersten Wand des Fusionsreaktors DEMO mittels einer Finite Elemente Simulation untersucht und bewertet. In diesem Rahmen werden Modell-Komponenten mit und ohne gradierter Zwischenschicht beruecksichtigt und der Vorzug eines FGM herausgestellt. Parameterstudien dienen einer konstruktiven Richtlinie fuer die strukturelle Umsetzung von FGMs und Komponenten der ersten Wand. Es wird ausserdem die Machbarkeit von vier Methoden (Magnetron Sputtering, Fluessigphaseninfiltration, modifiziertes atmosphaerisches Plasmaspritzen und Electro Discharge Sintering) hinsichtlich der Herstellung von FGMs studiert. Die entstehenden Schichten werden mikrostrukturell, thermo-physikalisch und mechanisch detailliert untersucht. Auf Grundlage dieser Charakterisierung und der Finite Elemente Simulation wird ihre Eignung als gradierte Schicht in der ersten Wand von DEMO evaluiert und schliesslich mit alternativen Fuegesystemen, die derzeit im Forschungsumfeld erprobt werden, verglichen.

  2. The use of ozone as microbiocide in cooling water treatment - experiences with an ''All-Organic'' program; Ozon als Mikrobizid bei der Kuehlwasserbehandlung - Praxiserfahrungen mit einem ''All-Organic'' Programm

    Energy Technology Data Exchange (ETDEWEB)

    Noks, E.; Olkis, A. [Deutsche Nalco Chemie GmbH, Frankfurt am Main (Germany); Kleinstueck, R. [Bayer AG, Leverkusen (Germany); Johnson, D.A. [Nalco Chemical Co., Naperville (United States)

    1999-10-01

    Kuehlwasserbehandlung. Als ein entscheidendes Kriterium zur Beurteilung der mikrobiologischen Aktivitaet und zur Steuerung des Ozoneintrags dienen regelmaessige Messungen von ATP-Werten und Gesamtkeimzahlen im System. Eine auf den Bedarf begrenzte Ozonkonzentration hilft die Abbauraten der organischen Inhibitoren gut unter Kontrolle zu halten und - mit einem Minimum an Behandlungsmitteln - entsprechend umweltfreundlich und wirtschaftlich zu arbeiten. Wiederfindungsraten von etwa 80% wurden fuer das Phosphonat PBTC und die Stabilisatoren und Dispergatoren gemessen. Die Korrosionsraten bei Stahl und Kupfer sind in Anbetracht der Zusatzwasserqualitaet niedrig. Die Ablagerungstendenz wird durch die Inhibitorkombination sicher kontrolliert. Vorangegangene Untersuchungen in Labor und Technikum hatten gezeigt, dass die haeufig als Basiskomponenten in Kuehlwasserformulierungen eingesetzten Phosphonate beim Kontakt mit Ozon eine sehr unterschiedliche und in der Reihenfolge PBTC>HEDP>ATMP sinkende Ozonstabilitaet aufweisen. Mit einem PBTC-haltigen stabilisierten Phosphatprogramm wurde in einem Kuehlkreislauf bei der Bayer AG in Dormagen ein 6-monatiger Praxisversuch durchgefuehrt. Trotz der hohen Halbwertszeiten des Kuehlwassers im System erwies sich PBTC mit Wiederfindungsraten von ca. 50 bis 80% als hinreichend stabil. (orig.)

  3. Development of a combined rotation anisotropy SHG, laser scanning and interferometric SHG microscopy system for material investigations

    International Nuclear Information System (INIS)

    Prylepa, A.

    2015-01-01

    wavelength of 1560 nm was assembled and operated for the first time. Due to the coherent detection scheme of iSHGM technique, we could demonstrate the successful registration of the SHG signal on the background of high level multi-photon luminescence.With the realised setup following results in the investigation of materials could be achieved. First, in the frame of cooperation with our industrial partner "voestalpine Stahl", with the help of SHG microscopy, we successfully detected the distribution of SHG-active corrosion products on the surface of metals also under a thick covering organic transparent layer, which is not possible by means of, e.g., the X-ray photo-electron spectroscopy (XPS) technique. The interest for multilayer silicon wafers is actively growing in the microelectronics area, especially in the last decade. A plasma activation process is commonly used for improving bonding of silicon wafers and decreasing the annealing temperature. The surface chemistry of the silicon wafers is changed after plasma treatment, therefore, detection of these changes is an important task. With the help of RA-SHG we detected SHG responses characterising the nano-structural changes of the surface of the plasma activated silicon wafers. Also, we successfully detected with the help of OCM the interface of two bonded silicon wafers, which allows to control the quality of bonding. Additionally, in a cooperative work with the theoretical group of ZONA, our RA-SHG measurements were used for the interpretation of the second-order nonlinear polarisation (in the case of nonlinear reflection) in centrosymmetric media by the simplified bond hyperpolarizability model suggesting the existence of a bulk dipole contribution. To summarize, the nonlinear optical methods have proved themselves as an attractive tool in a wide family of analytic techniques providing unique information about the structure of a variety of materials widely used in science, technology and production. (author) [de

  4. Insight into the Local Solvent Environment of Biologically Relevant Iron-nitroysl Systems through Two-Dimensional Infrared Spectroscopy

    Science.gov (United States)

    Brookes, Jennifer Faith

    Iron-nitrosyl systems, particularly in the form of heme proteins, with their iron metal active sites play an important role in biological systems. Heme proteins act as storage, transporters, and receptors for nitric oxide (NO), a signaling molecule that is important in immune, nervous, and cardiovascular systems of mammals. By better understanding the local environment of the active site of NO binding heme proteins we can gain insight into disease in which the NO pathways have been implicated. This is an important step to being able to develop pharmaceuticals targeting NO pathways in humans. Sodium nitroprusside ((SNP, Na2[Fe(CN)5is NO]·2H 2O) investigated as a model system for the active site of nitric oxide binding heme proteins. Using two-dimensional infrared spectroscopy (2D IR) to obtain dephasing dynamics of the nitrosyl stretch (nuNO) in a series of solvents we are able to better understand the local environment of the more complicated metalloproteins. Rigorous line shape analysis is performed by using nonlinear response theory to simulate 2D IR spectra which are then fit to experimental data in an iterative process to extract frequency-frequency correlation functions (FFCFs). The time scales obtained are then correlated to empirical solvent polarity parameters. The analysis of the 2D IR lineshapes reveal that the spectral diffusion timescale of the nuNO in SNP varies from 0.8 -- 4 ps and is negatively correlated with the empirical solvent polarity scales. We continue to investigate NO binding of metalloproteins through 2D IR experiments on nitrophorin 4 (NP4). NP4 is a pH-sensitive NO transporter protein present in the salivary gland of the blood sucking insect Rhodius prolixus which undergoes a pH sensitive structural change between a closed and open conformation allowing for the storage and delivery of NO. The two structures are observed spectroscopically as two distinct pH-dependent nu NO frequencies at ~1904 and ~1917 cm-1. We obtain FFCFs by globally

  5. Aspectos entomológicos de la enfermedad de Chagas en Huallaga y Picota, San Martín, Perú

    Directory of Open Access Journals (Sweden)

    Abraham G. Cáceres

    2010-03-01

    Full Text Available Introducción: Existe escasa información y no actualizada sobre la presencia de triatominos en el departamento de San Martín, zona amazónica de nuestro país, y es importante actualizarla, ya que hay reportes recientes de casos de enfermedad de Chagas procedentes de la amazonía peruana cuyos vectores serían triatominos silvestres. Objetivos: Conocer la distribución geográfica de triatominos hematófagos en Huallaga y Picota, San Martín, Perú. Determinar los índices entomológicos, sus hábitos alimenticios y caracterizar los tripanosomatídeos que portan. Diseño: Investigación descriptiva observacional. Lugar: Red de Salud Huallaga y Picota, Laboratorio Regional de la Región de Salud San Martín. Laboratorios del Instituto Nacional de Salud. Participantes: Viviendas de 6 distritos de las provincia de Huallaga y 9 de Picota, del Departamento de San Martín. Intervenciones: La búsqueda de triatominos fue en 3 362 viviendas de áreas periurbanas y rurales. Mediante la prueba de precipitina, se determinó la fuente de alimentación. Se aisló tripanosomatídeos mediante infección en ratones Balb/C e inoculación en medio agar sangre, y por PCR se caracterizó el genoma por amplificación del espaciador intergénico del gen miniexón. Principales medidas de resultados: Determinar si Huallaga y Picota, San Martín, Perú, son zonas de riesgo de enfermedad de Chagas. Resultados: En 46 viviendas, de 3 362 muestreadas se capturó 53 triatominos adultos pertenecientes a Rhodnius pictipes (56,6%, Panstrongylus geniculatus (41,5% y Eratyrus mucronatus (1,9%. Se reporta P. geniculatus por primera vez para las dos provincias. Los índices de infestación para ambas provincias fueron 1,4% y 3,8%, respectivamente, y corresponden al índice de infección natural; mientras que el índice de dispersión fue 30,1%. En R. pictipes se identificó cinco fuentes de alimentación (pollo, humano, perro, cobayo y gato y en P. geniculatus un perfil

  6. Fauna Triatominae no Estado da Bahia, Brasil: as espécies e distribuição geográfica

    Directory of Open Access Journals (Sweden)

    Ítalo A. Shetlock

    1972-10-01

    Full Text Available Este é a primeira de uma série de publicações sobre os triatomíneos do Estado da Bahia, com base nos dados obtidos na inspeção de 889.972 domicílios de 11.045 localidades do Estado, nos anos de 1957 a 1971, quando se coletaram 33.588 exemplares do hemíptero. Foram identificadas 18 espécies pertencentes a 4 gêneros, conforme a seguir e relatado. Triatoma rubrovária, referida em antiga citação, não mais ocorre no Estado. Triatoma bahiensis perdeu sua validade específica, sendo considerada apenas urna variedade de T. pessoal. Existem também variedades de outras espécies, as quais serão estudadas com mais detalhes noutros trabalhes futuros. Panstrongylus megistus é principalmente abundante na faixa litorânea do Estado, com florestas latifoleadas, onde as condições de umidade são elevadas e oclima, é tropical quente e úmido. É a espécie considerada de maior importância na transmissão da Doença de Chagas na Bahia. T. brasiliensis foi encontrada comumente nas áreas de clima estépico com vegetação xerófila. A sua presença em áreas de clima, tropical quente e úmido, foi traduzida como sendo uma variedade da espécie. O seu encontro em áreas de florestas latifoleadas úmidas com clima de selvas, foi aceito como devido, possivelmente, ao transporte mecânico. Verificou-se que T. infestans, antes limitada ao paralelo 16° nos climas mesotérmicos está se disseminando, provavelmente por ação mecânica para áreas possuidoras de características climáticas diversas. T. sórdida foi encontrada somente nas áreas de clima seco seguindo de uma maneira geral o curso dos rios. T. rubrofasciata permaneceu com sua distribuição limitada a duas cidades coloniais na zona litorânea, rarefazendo-se nestes últimos anos, provavelmente devido a higienização por que passam os locais de sua antiga penetração. O gênero Rhodnius que é representado pelo R. negletus, constou de um só exemplar coletado num domicílio, em zona

  7. Hábitos alimentares, infecção natural e distribuição de triotomíneos domiciliados na região nordeste do Brasil Feeding habits, natural infection and distribution of domiciliary Triatominae bugs Northeast of Brazil

    Directory of Open Access Journals (Sweden)

    Oswaldo Paulo Forattini

    1981-04-01

    Full Text Available São apresentadas as informações obtidas no inquérito triatomíneo levado a efeito na região nordeste do Brasil. As características biogeográficas incluem a presença de áreas semi-áridas da caatinga e amplas faixas transicionais com outras feições paisagísticas. Entre estas foram incluídas as da floresta tropical atlântica e as inclusões florestadas mais extensas. No período de 1975 a 1980 foram examinados 15.342 triotomíneos coletados no ambiente domiciliar, visando detectar as presenças de sangue ingerido e de infecção natural por Trypanosoma tipo cruzi. O conteúdo intestinal foi submetido a reações com antisoros para homem, cão, gato, roedor (Kattus, marsupial (Didelphis e ave (Gallus. Por ordem de freqüência, as espécies encontradas foram Triatoma pseudomaculada (40,6%, Panstrongylus megistus (19,7%, Triatoma brasiliensis e T. sordida (ambos com 14,3%, Rhodnius nasutus (6,1% e Triatoma infestans (1,1%; além de em algumas outras raras. A presença de sangue foi detectada em 42,4% e a infecção em 3,4% desse total de espécimens examinados. Observou-se elevada mobilidade alimentar, com coeficientes gerais de 54,8% para ave e 30,0% para homem. Em nível específico pôde determinar apreciável grau de antropofilia em P. megistus e, em menor intensidade, em T. brasiliensis. Por sua vez, T. infestans mostrou-se altamente antropófilo. Observou-se apreciável ornitofilia em T. pseudomaculata e T. sordida, com elevada intensidade em R. nasutus. Por outro lado, a presença de sangue humano em espécimens capturados no peridomicílio indicou a ocorrência de freqüente mobilidade espacial, com exceção de T. infestans que não mostrou evidências de abandonar o domicílio. A tendência à domiciliação, além desta, revelou-se apreciável em P. megistus, moderada em T. brasiliensi, T. pseudomaculata, T. sordida e praticamente nula em R. nasutus. A distribuição geográfica confirmou o caráter autóctone de T

  8. Modeling the geochemical distribution of rare earth elements (REEs using multivariate statistics in the eastern part of Marvast placer, the Yazd province

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    Amin Hossein Morshedy

    2017-07-01

    , H. and Milodowski, A.E., 2012. Occurrence and paragenesis of diagenetic monazite in the upper Triassic black shales of the Marvast region, South Yazd, Iran. Mineralogy and Petrology, 104(3-4: 197-210. Castor, S.B. and Hedrick, J.B., 2006. Rare earth elements. In: J.E. Kogel (Editors, Industrial minerals & rocks: commodities, markets, and uses. Society for mining, metallurgy, and exploration, Inc. (SME, Colorado, pp. 769-792. Everitt, B., Landau, S., Leese, M. and Stahl, D., 2011. Cluster Analysis. 5th ed., Wiley Publishing, Hoboken, Geological Survey of Iran (GSI, 2004. Exploration of rare earth element and monazite in the alluvium of the southern Marvast (eastern area. Tehran, 66 pp. (in Persian Ghorbani, M., 2013. The economic geology of Iran: mineral deposits and natural resources. Springer, London, 569 pp. Jain, A.K., Murty, M.N. and Flynn, P.J., 1999. Data clustering: a review. Association for Computing Machinery computing surveys, 31(3: 264-323. Jaireth, S., Hoatson D.M. and Miezitis Y., 2014. Geological setting and resources of the major rare-earth-element deposits in Australia. Ore Geology Reviews, 62: 72-128. Ji, H., Zeng, D., Shi, Y., Wu, Y. and Wu, X., 2007. Semi-hierarchical correspondence cluster analysis and regional geochemical pattern recognition. Journal of Geochemical Exploration, 93(2: 109-119.

  9. Area-wide control of Chagas disease vectors in Latin America

    International Nuclear Information System (INIS)

    Schofield, C.J.

    2000-01-01

    transmission by the year 2000 (WHO 1997b). Programme costs were originally estimated at US$190-350 million over the 10-year period, with most of the investment to be committed during the initial attack phase over the first 3 years. In fact, investment to date has been just over US200 million and recent studies in Brazil and Argentina have revealed economic rates of return in excess of 30% and 60%, respectively (Akhavan 1996, Basombrio et al. 1998). With successful control or elimination of T. infestans and R. prolixus and control of sympatric vectors, a figure approaching 70% of Chagas disease transmission will be interrupted, while large-scale improvements in blood bank screening will interrupt a further 10-15%. But maintenance of this success and further progress, will depend very largely on improved systems of entomological surveillance and these in turn will depend crucially on maintaining political continuity for the control and surveillance programmes. Although technologically simple, the administrative scale of the regional Chagas disease control initiatives has revealed major complexities and intervention coverage has not been entirely uniform. In each country the programmes have faced difficulties primarily of an administrative nature, especially as each country has simultaneously sought to decentralise its intervention services - producing inevitable disruption to the chain of operational decisions and lapses in entomological surveillance. Already there are indications of little-known species of Triatominae adapting to new domestic habitats and our understanding of this evolutionary process is still in its infancy. It should not be forgotten - especially by those responsible for budgetary priorities - that the domestication of Triatominae and initiation of Chagas disease transmission is a relatively recent phenomenon. Experience shows that we can now combat this, but if we relax vigilance, it could happen again

  10. Relevancia de la infección natural por Trypanosoma cruzi en triatominos selváticos provenientes de seis municipios de Santander, Colombia

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    Sergio Gómez

    2016-06-01

    genotipificación se realizó mediante PCR del espaciador intergénico del gen mini-exón (SL-IR, que amplifica fragmentos de 350 y 300 pb para T. cruzi I (TcI y T. cruzi II o V-VI (TcII-V-VI, respectivamente. Resultados: Se analizaron 50 especímenes adultos de Panstrongylus geniculatus (64% y Rhodnius pallescens (36% capturados principalmente en el domicilio y peridomicilio, respectivamente. La TI en los triatominos fue de 53,6% al examen directo y de 68,0% mediante PCR de satADN. La TI fue mayor para R. pallescens (77,8% en comparación con P. geniculatus (62,5%. Se observaron altas tasas de infección en triatominos provenientes de Floridablanca (90,9%, Bucaramanga (66,7% y Capitanejo (50,0%. En San Vicente de Chucurí y Lebrija también se detectaron altos índices de infección, no obstante, el número de vectores capturados en estos municipios fue muy bajo (entre 1 y 3. Se determinaron las DTUs de las poblaciones de T. cruzi presentes en el 41,2% de los triatominos selváticos positivos por PCR de satADN. En ambas especies vectoriales se evidenció el predominio de TcI (86% y una alta frecuencia (33% de infección mixta por TcI y TcII-V-VI en R. pallescens. Conclusiones: Se determinó la alta tasa de infección por T. cruzi en triatominos selváticos capturados en los municipios evaluados, lo cual resalta su importancia epidemiológica por la posibilidad de transmisión del parásito por vía oral, aún en zonas de baja endemia o donde no hay reporte de vectores domiciliados. Igualmente, es urgente la implementación de estrategias de control dirigidas a prevenir la intrusión domiciliaria de estos vectores.

  11. Atypical antipsychotics for disruptive behaviour disorders in children and youths.

    Science.gov (United States)

    Loy, Jik H; Merry, Sally N; Hetrick, Sarah E; Stasiak, Karolina

    2017-08-09

    This is an update of the original Cochrane Review, last published in 2012 (Loy 2012). Children and youths with disruptive behaviour disorders may present to health services, where they may be treated with atypical antipsychotics. There is increasing usage of atypical antipsychotics in the treatment of disruptive behaviour disorders. To evaluate the effect and safety of atypical antipsychotics, compared to placebo, for treating disruptive behaviour disorders in children and youths. The aim was to evaluate each drug separately rather than the class effect, on the grounds that each atypical antipsychotic has different pharmacologic binding profile (Stahl 2013) and that this is clinically more useful. In January 2017, we searched CENTRAL, MEDLINE, Embase, five other databases and two trials registers. Randomised controlled trials of atypical antipsychotics versus placebo in children and youths aged up to and including 18 years, with a diagnosis of disruptive behaviour disorders, including comorbid ADHD. The primary outcomes were aggression, conduct problems and adverse events (i.e. weight gain/changes and metabolic parameters). The secondary outcomes were general functioning, noncompliance, other adverse events, social functioning, family functioning, parent satisfaction and school functioning. We used standard methodological procedures expected by Cochrane. Two review authors (JL and KS) independently collected, evaluated and extracted data. We used the GRADE approach to assess the quality of the evidence. We performed meta-analyses for each of our primary outcomes, except for metabolic parameters, due to inadequate outcome data. We included 10 trials (spanning 2000 to 2014), involving a total of 896 children and youths aged five to 18 years. Bar two trials, all came from an outpatient setting. Eight trials assessed risperidone, one assessed quetiapine and one assessed ziprasidone. Nine trials assessed acute efficacy (over four to 10 weeks); one of which combined

  12. Late Pleistocene and Holocene paleoseismology of an intraplate seismic zone in a large alluvial valley, the New Madrid seismic zone, Central USA

    Science.gov (United States)

    Guccione, Margaret J.

    2005-10-01

    .P., Schweig, E.S., Sims, J.D., Lafferty, R.H., Wolf, L.W., Haynes, M.L., 2002. The earthquake potential of the New Madrid seismic zone, Bulletin of the Seismological Society of America, v 92, n. 6, p. 2080 2089; Tuttle, M.P., Schweig III, E.S., Campbell, J., Thomas, P.M., Sims, J.D., Lafferty III, R.H., 2005. Evidence for New Madrid earthquakes in A.D. 300 and 2350 B.C. Seismological Research Letters 76, 489 501]). The two most recent prehistoric and the 2350 B.C. events were probably also earthquake sequences with approximately the same magnitude as the historic sequence. Surface deformation (faulting and folding) in an alluvial setting provides many examples of stream response to gradient changes that can also be used to date past earthquake events. Stream responses include changes in channel morphology, deviations in the channel path from the regional gradient, changes in the direction of flow, anomalous longitudinal profiles, and aggradation or incision of the channel ([Merritts, D., Hesterberg, T, 1994. Stream networks and long-term surface uplift in the New Madrid seismic zone. Science 265, 1081 1084.; Guccione, M.J., Mueller, K., Champion, J., Shepherd, S., Odhiambo, B., 2002b. Stream response to repeated co-seismic folding, Tiptonville dome, western Tennessee. Geomorphology 43 (2002), 313 349]). Uplift or depression of the floodplain affects the frequency of flooding and thus the thickness and style of vertical accretion or drowning of a meander scar to form a lake. Vegetation may experience trauma, mortality, and in some cases growth enhancement due to ground failure during the earthquake and hydrologic changes after the earthquake ([VanArdale, R.B., Stahle, D.W., Cleaveland, M.K., Guccione, M.J., 1998. Earthquake signals in tree-ring data from the New Madrid seismic zone and implications for paleoseismicity. Geology 26, 515 518]). Identification and dating these physical and biologic responses allows source areas to be identified and seismic events to be dated

  13. A systematic revision of Operclipygus Marseul (Coleoptera, Histeridae, Exosternini

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    Michael Caterino

    2013-02-01

    . panamensis (Wenzel & Dybas, 1941], O. sejunctus group [O. depressus (Hinton, 1935, O. itoupe sp. n., O. juninensis sp. n., O. pecki sp. n., O. punctiventer sp. n., O. sejunctus (Schmidt, 1896 comb. n., O. setiventris sp. n.], O. mortavis group [O. ecitonis sp. n., O. mortavis sp. n., O. paraguensis sp. n.], O. dytiscoides group [O. carinisternus sp. n., O. crenulatus sp. n., O. dytiscoides sp. n., O. quadratus sp. n.], O. dubitabilis group [O. dubitabilis (Marseul, 1889, O. yasuni sp. n.], O. angulifer group [O. angulifer sp. n., O. impressifrons sp. n.], O. dubius group [O. andinus sp. n., O. dubius (Lewis, 1888, O. extraneus sp. n., O. intermissus sp. n., O. lunulus sp. n., O. occultus sp. n., O. perplexus sp. n., O. remotus sp. n., O. validus sp. n., O. variabilis sp. n.], O. hospes group [O. assimilis sp. n., O. belemensis sp. n., O. bulbistoma sp. n., O. callifrons sp. n., O. colombicus sp. n., O. communis sp. n., O. confertus sp. n., O. confluens sp. n., O. curtistrius sp. n., O. diffluens sp. n., O. fusistrius sp. n., O. gratus sp. n., O. hospes (Lewis, 1902, O. ibiscus sp. n., O. ignifer sp. n., O. impositus sp. n., O. incisus sp. n., O. innocuus sp. n., O. inquilinus sp. n., O. minutus sp. n., O. novateutoniae sp. n., O. praecinctus sp. n., O. prominens sp. n., O. rileyi sp. n., O. subterraneus sp. n., O. tenuis sp. n., O. tiputinus sp. n.], O. farctus group [O. atlanticus sp. n., O. bidessois (Marseul, 1889, O. distinctus (Hinton, 1935, O. distractus (Schmidt, 1896 comb. n., O. farctissimus sp. n., O. farctus (Marseul, 1864, O. gilli sp. n., O. impressistrius sp. n., O. inflatus sp. n., O. latemarginatus (Bickhardt, 1920 comb. n., O. petrovi sp. n., O. plicatus (Hinton, 1935 comb. n., O. prolixus sp. n., O. punctifrons sp. n., O. proximus sp. n., O. subrufus sp. n.], O. hirsutipes group [O. guianensis sp. n., O. hirsutipes sp. n.], O. hamistrius group [O. arquus sp. n., O. campbelli sp. n., O. chiapensis sp. n., O. dybasi sp. n., O. geometricus (Casey, 1893 comb. n

  14. Encyclopedia of Information Ethics and Security

    Directory of Open Access Journals (Sweden)

    Reviewed by Yavuz AKBULUT

    2008-01-01

    of technology andanimation. Her recent publications are Women Do Animate: Interviews with 10Australian Animators (Insight Publications, 2005 and Information Security and Ethics:Social and Organizational Issues (IRM Press, 2004. The Editorial Advisory Boardmembers who contributed to the work as both reviewers and authors are Kathy Blashki(Deakin University, Australia, Matthew Butler (Monash University, Australia, HeatherFulford (The Robert Gordon University, UK, James E. Goldman (Purdue University,234USA, Katina Michael (University of Wollongong, Australia and Bernd Carsten Stahl (DeMontfort University, UK.A diverse set of topics are covered by different entries addressing a wide range of lifeareas affected by information and communication technologies. These topics includeeducation, the workplace, health, privacy, intellectual property, identity, computercrime, cyber terrorism, equity and access, banking, shopping, publishing, legal andpolitical issues, censorship, artificial intelligence, the environment and communication.As stated by the editor, ‗apart from providing information about current and possiblefuture technological developments, the volume contains much thought-provokingmaterial concerning the social and moral implications of information andcommunication technologies which are of immense importance to us all‘ (p. xiv.It is important for ordinary citizens as well as professionals in the field to involve in thedebates regarding the transformative effects of information and communicationtechnologies on our lives. In this respect, the book serves as a great reference sourcefor professionals working on information and communication technologies,professionals teaching at educational institutions, both experienced and noviceresearchers interested in the field, and ordinary citizens who want to be enlightenedabout ethical practices and implications of information and communicationtechnologies. In addition, moral and social implications of information