Environmental management for the control of Triatoma dimidiata (Latreille, 1811, (Hemiptera: Reduviidae in Costa Rica: a pilot project

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Rodrigo Zeledón

2006-06-01

Full Text Available An ecological control method, using environmental management operations, based on biological and behavioral characteristics of Triatoma dimidiata (Latreille, 1811, was implemented as a pilot project in an area of Costa Rica where the bug is prevalent. The sample was represented by 20 houses with peridomestic colonies (two also had indoor infestation, divided in two equivalent groups of 10 each. In one group we intervened the houses, i.e. all objects or materials that were serving as artificial ecotopes for the bugs were removed, and the second group was used as control houses. After a year of periodic follow up, it became evident that in those houses with a modified environment the number of insects had decreased notoriously even after the first visits and this was more evident after a period of 12.5 to 13.5 months in which no insects were detected in eight of the houses. It also became clear that in this group of houses, recolonization by wild bugs from the surrounding areas, became more difficult, probably due to the absence of protection from bug predators. In the control houses, with the exception of three in which the inhabitants decided to intervene on their own, and another house with a peculiar situation, the insect populations remained the same or even showed a tendency to increase, as confirmed at the end of the experiment. We believe that the method is feasible, low costing and non contaminating. It could be used successfully in other places where T. dimidiata is common and also in countries where other species colonize peridomestic areas of homes. Environmental management of this kind should seek the participation of the members of the communities, in order to make it a more permanent control measure.

Triatoma dimidiata infestation in Chagas disease endemic regions of Guatemala: comparison of random and targeted cross-sectional surveys.

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Raymond J King

Full Text Available BACKGROUND: Guatemala is presently engaged in the Central America Initiative to interrupt Chagas disease transmission by reducing intradomiciliary prevalence of Triatoma dimidiata, using targeted cross-sectional surveys to direct control measures to villages exceeding the 5% control threshold. The use of targeted surveys to guide disease control programs has not been evaluated. Here, we compare the findings from the targeted surveys to concurrent random cross-sectional surveys in two primary foci of Chagas disease transmission in central and southeastern Guatemala. METHODOLOGY/PRINCIPAL FINDINGS: Survey prevalences of T. dimidiata intradomiciliary infestation by village and region were compared. Univariate logistic regression was used to assess the use of risk factors to target surveys and to evaluate indicators associated with village level intradomiciliary prevalences >5% by survey and region. Multivariate logistic regression models were developed to assess the ability of random and targeted surveys to target villages with intradomiciliary prevalence exceeding the control threshold within each region. Regional prevalences did not vary by survey; however, village prevalences were significantly greater in random surveys in central (13.0% versus 8.7% and southeastern (22.7% versus 6.9% Guatemala. The number of significant risk factors detected did not vary by survey in central Guatemala but differed considerably in the southeast with a greater number of significant risk factors in the random survey (e.g. land surface temperature, relative humidity, cropland, grassland, tile flooring, and stick and mud and palm and straw walls. Differences in the direction of risk factor associations were observed between regions in both survey types. The overall discriminative capacity was significantly greater in the random surveys in central and southeastern Guatemala, with an area under the receiver-operator curve (AUC of 0.84 in the random surveys and

The Chagas disease domestic transmission cycle in Guatemala: Parasite-vector switches and lack of mitochondrial co-diversification between Triatoma dimidiata and Trypanosoma cruzi subpopulations suggest non-vectorial parasite dispersal across the Motagua valley.

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Pennington, Pamela M; Messenger, Louisa Alexandra; Reina, Jeffrey; Juárez, José G; Lawrence, Gena G; Dotson, Ellen M; Llewellyn, Martin S; Cordón-Rosales, Celia

2015-11-01

Parasites transmitted by insects must adapt to their vectors and reservoirs. Chagas disease, an American zoonosis caused by Trypanosoma cruzi, is transmitted by several species of triatomines. In Central America, Triatoma dimidiata is a widely dispersed vector found in sylvatic and domestic habitats, with distinct populations across the endemic region of Guatemala. Our aim was to test the strength of association between vector and parasite genetic divergence in domestic environments. Microsatellite (MS) loci were used to characterize parasites isolated from T. dimidiata (n=112) collected in domestic environments. Moderate genetic differentiation was observed between parasites north and south of the Motagua Valley, an ancient biogeographic barrier (FST 0.138, p=0.009). Slightly reduced genotypic diversity and increased heterozygosity in the north (Allelic richness (Ar)=1.00-6.05, FIS -0.03) compared to the south (Ar=1.47-6.30, FIS 0.022) suggest either a selective or demographic process during parasite dispersal. Based on parasite genotypes and geographic distribution, 15 vector specimens and their parasite isolates were selected for mitochondrial co-diversification analysis. Genetic variability and phylogenetic congruence were determined with mitochondrial DNA sequences (10 parasite maxicircle gene fragments and triatomine ND4+CYT b). A Mantel test as well as phylogenetic, network and principal coordinates analyses supported at least three T. dimidiata haplogroups separated by geographic distance across the Motagua Valley. Maxicircle sequences showed low T. cruzi genetic variability (π nucleotide diversity 0.00098) with no evidence of co-diversification with the vector, having multiple host switches across the valley. Sylvatic Didelphis marsupialis captured across the Motagua Valley were found to be infected with T. cruzi strains sharing MS genotypes with parasites isolated from domiciliated triatomines. The current parasite distribution in domestic environments

Triatoma dimidiata en Colombia; distribución, ecología e importancia epidemiológica

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Óscar Quirós-Gómez

2017-06-01

La comprensión de las relaciones de T. dimidiata con su hábitat, así como el empoderamiento de la comunidad, contribuyen al desarrollo de sistemas de control efectivos y perdurables. El propósito de esta revisión fue describir la distribución, los factores de riesgo, la ecología, las características entomológicas y los hábitats de las poblaciones de T. dimidiata en Colombia, y proponer alternativas de intervención acordes con las características particulares de esta especie.

Spatio-temporal analysis of the biophysical and ecological conditions of Triatoma dimidiata (Hemiptera: Reduviidae: Triatominae in the northeast region of Colombia

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Jaime Badel-Mogollón

2017-03-01

Conclusions: Surface temperature and soil coverage were the variables that better explained the life cycle of T. dimidiata in the area. High relative humidity promoted the seek of shelters and an increase of the geographic distribution in the annual and biannual peaks of regional rainfall. The ecologic and anthropic conditions suggest that T. dimidiata is a highly resilient species.

Efecto tóxico de b-cipermetrina, deltametrina y fenitrotión en cepas de Triatoma dimidiata (Latreille, 1811 y Triatoma maculata (Erichson, 1848 (Hemiptera, Reduviidae

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Marlene Reyes

2007-01-01

Conclusión. En ninfas de primer estadio de T. dimidiata y T. maculata los insecticidas piretroides fueron mas efectivos; en ninfas de quinto estadio de T. dimidiata la efectividad de los piretroides del organofosforado fue diferente con las DL50; las ninfas de este estadio requirieron dosis altas comparadas con las utilizadas para otros triatominos, lo cual sugiere una baja susceptibilidad. La DL99 para el organofosforado fue significativamente menor, lo que podría indicar una mayor efectividad en campo. Es importante realizar estudios de efectos sinergistas para mostrar el posible rol de mecanismos bioquímicos que determine su tolerancia a los piretroides, esto representa un nuevo reto para las campañas de control en los países andinos y centroamericanos donde esta especie es endémica.

Eco-bio-social determinants for house infestation by non-domiciliated Triatoma dimidiata in the Yucatan Peninsula, Mexico.

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Eric Dumonteil

Full Text Available BACKGROUND: Chagas disease is a vector-borne disease of major importance in the Americas. Disease prevention is mostly limited to vector control. Integrated interventions targeting ecological, biological and social determinants of vector-borne diseases are increasingly used for improved control. METHODOLOGY/PRINCIPAL FINDINGS: We investigated key factors associated with transient house infestation by T. dimidiata in rural villages in Yucatan, Mexico, using a mixed modeling approach based on initial null-hypothesis testing followed by multimodel inference and averaging on data from 308 houses from three villages. We found that the presence of dogs, chickens and potential refuges, such as rock piles, in the peridomicile as well as the proximity of houses to vegetation at the periphery of the village and to public light sources are major risk factors for infestation. These factors explain most of the intra-village variations in infestation. CONCLUSIONS/SIGNIFICANCE: These results underline a process of infestation distinct from that of domiciliated triatomines and may be used for risk stratification of houses for both vector surveillance and control. Combined integrated vector interventions, informed by an Ecohealth perspective, should aim at targeting several of these factors to effectively reduce infestation and provide sustainable vector control.

Revalidation and redescription of Triatoma brasiliensis macromelasoma Galvão, 1956 and an identification key for the Triatoma brasiliensis complex (Hemiptera: Reduviidae: Triatominae

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Jane Costa

2013-09-01

Full Text Available Triatoma brasiliensis macromelasoma is revalidated based on the results of previous multidisciplinary studies on the Triatoma brasiliensis complex, consisting of crossing experiments and morphological, biological, ecological and molecular analyses. These taxonomic tools showed the closest relationship between T. b. macromelasoma and Triatoma brasiliensis brasiliensis. T. b. macromelasoma is redescribed based on specimens collected in the type locality and specimens from a F1 colony. The complex now comprises T. b. brasiliensis, T. b. macromelasoma, Triatoma melanica, Triatoma juazeirensis and Triatoma sherlocki. An identification key for all members of the complex is presented. This detailed comparative study of the morphological features of T. b. macromelasoma and the remaining members of the complex corroborates results from multidisciplinary analyses, suggesting that the subspecific status is applicable. This subspecies can be distinguished by the following combination of features: a pronotum with 1+1 narrow brownish-yellow stripes on the submedian carinae, not attaining its apex, hemelytra with membrane cells darkened on the central portion and legs with an incomplete brownish-yellow ring on the apical half of the femora. Because the T. brasiliensis complex is of distinct epidemiological importance throughout its geographic distribution, a precise identification of its five members is important for monitoring and controlling actions against Chagas disease transmission.

Ciclo de vida de Triatoma dimidiata Latreille, 1811 (Hemiptera, Reduviidae en condiciones de laboratorio: producción de ninfas para ensayos biológicos

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Marlene Reyes

2009-03-01

Conclusión. T. dimidiata presentó un tiempo de desarrollo intermedio entre los triatominos con amplio rango para algunos individuos, posiblemente debido a la irregularidad en su alimentación. La identificación de un rango de peso homogéneo después de 22 días de ayuno con gran producción de ninfas de V estadio, facilita la aplicación de protocolos estandarizados para establecer criterios de selección de compuestos insecticidas utilizables en los programas de control.

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.

Triatoma melanosoma, novo status para Triatoma infestans melanosoma Martinez, Olmedo & Carcavallo, 1987 (Hemiptera: Reduviidae Triatoma melanosoma, new status for Triatoma infestans melanosoma Martinez, Olmedo & Carcavallo, 1987 (Hemiptera: Reduviidae

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Herman Lent

1994-09-01

Full Text Available Triatoma infestans melanosoma was described in 1987 by Martinez, Olmedo & Carcavallo. In the present work the authors make a redescription, adding new characters, and based on biological and morphological aspects raise up to the level of species and being identified as Triatoma melanosoma. A detailed morphological study of the external male genitalia was made.

Comparative study of the stridulatorium sulcus, buccula and rostrum of nymphs of Triatoma klugi Carcavallo et al, Triatoma vandae Carcavallo et al and Triatoma williami Galvao et al (Hemiptera: Redivide)

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Silva, Maria B.A.; Jurberg, Jose; Galvao, Cleber; Barbosa, Helene S.

2010-01-01

Ultrastructural analysis of the ventral region of the head - rostrum, buccula and stridulatorium sulcus - of 1st, 3rd and 5th instars of Triatoma klugi Carcavallo et al, Triatoma vandae Carcavallo et al, and Triatoma williami Galvao et al, are described in here. Morphological differences in the analyzed structures for all three Triatoma species studied were detected under scanning electron microscopy, allowing their grouping by their morphological similarities. Species-specific differences at each nymphal development stage were analyzed as well. (author)

Comparative study of the stridulatorium sulcus, buccula and rostrum of nymphs of Triatoma klugi Carcavallo et al, Triatoma vandae Carcavallo et al and Triatoma williami Galvao et al (Hemiptera: Redivide)

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Silva, Maria B.A.; Jurberg, Jose; Galvao, Cleber; Barbosa, Helene S. [Instituto Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ (Brazil). Lab. de Biologia Estrutural. Lab. Nacional e Internacional de Referencia em Taxonomia de Triatomineos

2010-01-15

Ultrastructural analysis of the ventral region of the head - rostrum, buccula and stridulatorium sulcus - of 1st, 3rd and 5th instars of Triatoma klugi Carcavallo et al, Triatoma vandae Carcavallo et al, and Triatoma williami Galvao et al, are described in here. Morphological differences in the analyzed structures for all three Triatoma species studied were detected under scanning electron microscopy, allowing their grouping by their morphological similarities. Species-specific differences at each nymphal development stage were analyzed as well. (author)

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Results 671 - 680 of 6389 ... ... private spaces, and can be related to any combination of caste, gender, race. ... Previously identified risk factors for persistent Triatoma dimidiata ... A matched firm-employee data set is used to examine the extent of ...

Chromosome homogeneity in populations of Triatoma brasiliensis Neiva 1911 (Hemiptera - Reduviidae - Triatominae

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Panzera Francisco

2000-01-01

Full Text Available Triatoma brasiliensis is the most important vector of Chagas disease in the semiarid zone of the Northeast of Brazil. Several authors have reported the occurrence of four chromatic patterns with morphological, ecological, and genetic differences. In order to determine the existence of cytogenetic differentiation between these chromatic forms, we analyzed their karyotypes and the chromosome behavior during the male meiotic process. Triatoma brasiliensis shows distinct and specific chromosome characteristics, which differ from those observed in all other triatomine species. However, no cytogenetic differences were observed between the four chromatic forms of T. brasiliensis. The lack of chromosome differentiation among them could indicate that the populations of this species are in a process of differentiation that does not involve their chromosomal organization.

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.

The biology of three Mexican-American species of Triatominae (Hemiptera: Reduviidae: Triatoma recurva, Triatoma protracta and Triatoma rubida

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José Alejandro Martínez-Ibarra

2012-08-01

Full Text Available The values of biological parameters related to hatching, lifespan, the number of blood meals between moults, mortality, time lapse before the beginning of feeding, feeding time and defecation delay for each instar of three Mexican-American species of Triatominae, Triatoma recurva, Triatoma protracta (former subspecies protracta and Triatoma rubida (former subspecies uhleri, were evaluated and compared. No significant (p > 0.05 differences were recorded among the three species with respect to the average time required to hatch. This time was approximately 19 days. The average egg-to-adult development time was significantly (p < 0.05 shorter for T. rubida. The number of blood meals at each nymphal instar varied from one-five for each species. The mortality rates were higher for the first-instar nymphs of the three species studied. The mean time lapse before the beginning of feeding was between 0.3-3 min for most nymphs of all instars of each species studied. The mean feeding time was the longest for T. recurva, followed by T. protracta. The defecation delay was less than 10 min for T. recurva and T. rubida. Given these results, only T. rubida should be considered an important potential vector of Trypanosoma cruzi transmission to humans in areas of Mexico where these species exist, whereas T. recurva and T. protracta would be of secondary importance.

Ciclo evolutivo do Hepatozoon triatomae (Sporozoa, Haemogregarinidae parasita de triatomíneos Evolution cycle of the Hepatozoon triatomae (Sporozoa, Haemogregarinidae, parasite of triatominea

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Eduardo Olavo da Rocha e Silva

1975-09-01

Full Text Available Relata-se o encontro no Estado de São Paulo, Brasil, de triatomíneos e lagartos, respectivamente o Triatoma arthurneivai e Tropidurus torquatus, parasitados por uma hemogregarina semelhante a Hepatozoon triatomae (Osimani, 1942 Reichenow, 1953. São apresentados aspectos da sua morfologia e estudadas as diversas fases do seu ciclo evolutivo, este inteiramente reproduzido em laboratório.The author relates the discovery of Triatoma arthurneivai and Tropidurus torquatus, in the localities of Lavras de Cima and Santo Antonio, State of São Paulo, Brazil, infected by a hemogregarine similar to Hepatozoon triatomae (Osimani, 1942 Reichenow 1953. He presents certain aspects of its morphology and also studies the several phases of its evolution cycle, which were completed in the laboratory.

Ecología urbana de Triatoma infestans en Argentina: asociación entre Triatoma infestans y palomares Triatoma infestans urban ecology in Argentina: association between Triatoma infestans and pigeon cotes

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Silvana L. Vallvé

1995-06-01

Full Text Available Estudio se realizó en una área urbana de la Capital de la Provincia de San Juan, Argentina, en un barrio de 768 apartamentos distribuidos en edificios de 3 y 7 pisos que rodean una bodega central abandonada. Se capturaron 329 ejemplares de Triatoma infestans, 293 en 4 terrazas de torres de 7 pisos y 36 en el interior de la bodega, associados con numerosas palomas que colomizaban estos sitios. Los insectos se refugiaban en el guano acumulado entre bloques de cemento que cubren las terrazas y en la bodega dentro de toneles en desuso. Se identificaron dos focos principales de vectores associados con densos palomares: un 81,5% del total de triatomas colectados se halló en una de las torres y un 11% en la bodega. A los 6 meses del tratamiento insecticida, resultaron positivas terrazas en las que previamente no se habia capturado T. infestans. El perfil alimentario de los triatomas muestra un predominio de ingestas simples sobre ave; en los edificios y en la bodega el 95% de los T. infestans analizados se alimentó sólo de ave; el resto fueron ingestas simples o dobles sobre humano, perro o gato. Ningún T. infestans presentó infección con Trypanosoma cruzi.Estudo realizado em local urbano da capital da Província de San Juan, Argentina, num bairro de 768 apartamentos distribuídos em prédios de 3 e 7 andares que cingem uma adega vinícola abandonada. Foram coletados 329 exemplares de Triatoma infestans, 293 em 4 terraços das torres de 7 andares e 36 no interior da adega, associados às numerosas pombas que colonizavam esses sítios. Os insetos refugiavam-se no excremento cumulado entre os blocos de cimento que cobrem os terraços e, na adega, dentro de tonéis fora de uso. Foram identificados dois focos principais de vetores, associados com densos pombais: 81,5% do total de triatomas coletados foram apanhados em uma das torres e 11% na adega. Após 6 meses de tratamento com inseticida, foram positivos os terraços onde anteriormente não se

Performance of yeast-baited traps with Triatoma sordida, Triatoma brasiliensis, Triatoma pseudomaculata, and Panstrongylus megistus in laboratory assays Rendimiento de trampas cebadas con levaduras en la captura de Triatoma sordida, Triatoma brasiliensis, Triatoma pseudomaculata y Panstrongylus megistus en experimentos de laboratorio

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Herton H. R. Pires

2000-06-01

Full Text Available The effectiveness of a trap for triatomines baited with yeast cultures has been previously demonstrated for Triatoma infestans in laboratory assays. We report here results from laboratory assays testing yeast traps for Triatoma sordida, Triatoma brasiliensis, Triatoma pseudomaculata, and Panstrongylus megistus. All assays were conducted in an open experimental arena 100 cm X 100 cm, with two traps placed at opposite sides of the arena. One of the traps contained a yeast culture, and the other trap contained a saccharose solution as a control. Two series of experiments were done, one without a refuge for the insects and one with a refuge. The results obtained clearly demonstrated that the yeast-baited traps were effective in the laboratory in capturing both T. sordida and P. megistus. For T. sordida, yeast-baited traps captured significantly more bugs than did the control traps (t test P value = 0.03. For P. megistus, when a refuge was provided during the assay, yeast-baited traps also captured significantly more bugs than did the control traps (t test P value = 0.006. In the experiments with T. brasiliensis and T. pseudomaculata, both traps captured some insects, but the yeast traps captured many fewer bugs than was true with the T. sordida and P. megistus bugs. These results indicate that, in the laboratory, yeast traps can capture considerable numbers of T. sordida and P. megistus in one night. We discuss the potential use of yeast traps for detecting and capturing both triatomine species.Con anterioridad se ha demostrado la eficacia de las trampas cebadas con cultivos de levaduras (TCL para capturar Triatoma infestans en experimentos de laboratorio. En el presente estudio se describen los resultados obtenidos con estas trampas para capturar T. sordida, T. brasiliensis, T. pseudomaculata y Panstrongylus megistus, también en experimentos de laboratorio. Todos los experimentos fueron realizados en un recinto experimental abierto de 100 cm por

Interacción entre poblaciones de Triatoma infestans y Triatoma sordida

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Maria Esther Bar

1994-02-01

Full Text Available Para conocer si se producía algún tipo de interacción entre poblaciones de Triatoma infestans y Triatoma sordida que convivían en una unidad experimental y explotaban el mismo recurso alimentario (ave se las estudió desde setiembre/1988 a abril/1989. La composición etaria inicial para cada especie fue: 27 N1, 7 N2, 11 N3, 3 N4, 8 N5, 4 machos y 10 hembras. La dinámica de población, el estado nutricional, la predación y la conducta gregaria, utilizados como parámetros de comparación, fueron estimados mediante censos mensuales. Triatoma infestans logró mayor éxito colonizador que T. sordida dado los valores alcanzados en: fecundidad (146 huevos/hembra, longevidad (157,8 días y mortalidad (39,4%, en comparación a los obtenidos por T. sordida: 118 huevos/hembra, 81,1 días y 54,0% respectivamente. La población de T. infestans tuvo un crecimiento de tipo exponencial, con una alta tasa de renovación ninfal, en contraposición, la población de T. sordida se extinguió tempranamente. En general, el peso promedio de los ejemplares de T. infestans se mantuvo en valores próximos al inicial, mientras que en T. sordida se redujo. Los grupos gregarios se conformaron mayoritariamente en el sector inferior de la pared 1 (próximo al hospedador, observándose mayor nivel de contagio en T. infestans. A partir de los resultados obtenidos se formula la hipótesis de la superioridad competitiva en T. infestans.

Interacción entre poblaciones de Triatoma infestans y Triatoma sordida

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Bar Maria Esther

1994-01-01

Full Text Available Para conocer si se producía algún tipo de interacción entre poblaciones de Triatoma infestans y Triatoma sordida que convivían en una unidad experimental y explotaban el mismo recurso alimentario (ave se las estudió desde setiembre/1988 a abril/1989. La composición etaria inicial para cada especie fue: 27 N1, 7 N2, 11 N3, 3 N4, 8 N5, 4 machos y 10 hembras. La dinámica de población, el estado nutricional, la predación y la conducta gregaria, utilizados como parámetros de comparación, fueron estimados mediante censos mensuales. Triatoma infestans logró mayor éxito colonizador que T. sordida dado los valores alcanzados en: fecundidad (146 huevos/hembra, longevidad (157,8 días y mortalidad (39,4%, en comparación a los obtenidos por T. sordida: 118 huevos/hembra, 81,1 días y 54,0% respectivamente. La población de T. infestans tuvo un crecimiento de tipo exponencial, con una alta tasa de renovación ninfal, en contraposición, la población de T. sordida se extinguió tempranamente. En general, el peso promedio de los ejemplares de T. infestans se mantuvo en valores próximos al inicial, mientras que en T. sordida se redujo. Los grupos gregarios se conformaron mayoritariamente en el sector inferior de la pared 1 (próximo al hospedador, observándose mayor nivel de contagio en T. infestans. A partir de los resultados obtenidos se formula la hipótesis de la superioridad competitiva en T. infestans.

Population differentiation of the Chagas disease vector Triatoma maculata (Erichson, 1848) from Colombia and Venezuela.

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Monsalve, Yoman; Panzera, Francisco; Herrera, Leidi; Triana-Chávez, Omar; Gómez-Palacio, Andrés

2016-06-01

The emerging vector of Chagas disease, Triatoma maculata (Hemiptera, Reduviidae), is one of the most widely distributed Triatoma species in northern South America. Despite its increasing relevance as a vector, no consistent picture of the magnitude of genetic and phenetic diversity has yet been developed. Here, several populations of T. maculata from eleven Colombia and Venezuela localities were analyzed based on the morphometry of wings and the mitochondrial NADH dehydrogenase subunit 4 (ND4) gene sequences. Our results showed clear morphometric and genetic differences among Colombian and Venezuelan populations, indicating high intraspecific diversity. Inter-population divergence is suggested related to East Cordillera in Colombia. Analyses of other populations from Colombia, Venezuela, and Brazil from distinct eco-geographic regions are still needed to understand its systematics and phylogeography as well as its actual role as a vector of Chagas disease. © 2016 The Society for Vector Ecology.

Interacción entre poblaciones de Triatoma infestans y Triatoma sordida Interação entre população de Triatoma infestans e Triatoma sordida Population interactions between Triatoma infestans and Triatoma sordida

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Maria Esther Bar

1994-02-01

Full Text Available Para conocer si se producía algún tipo de interacción entre poblaciones de Triatoma infestans y Triatoma sordida que convivían en una unidad experimental y explotaban el mismo recurso alimentario (ave se las estudió desde setiembre/1988 a abril/1989. La composición etaria inicial para cada especie fue: 27 N1, 7 N2, 11 N3, 3 N4, 8 N5, 4 machos y 10 hembras. La dinámica de población, el estado nutricional, la predación y la conducta gregaria, utilizados como parámetros de comparación, fueron estimados mediante censos mensuales. Triatoma infestans logró mayor éxito colonizador que T. sordida dado los valores alcanzados en: fecundidad (146 huevos/hembra, longevidad (157,8 días y mortalidad (39,4%, en comparación a los obtenidos por T. sordida: 118 huevos/hembra, 81,1 días y 54,0% respectivamente. La población de T. infestans tuvo un crecimiento de tipo exponencial, con una alta tasa de renovación ninfal, en contraposición, la población de T. sordida se extinguió tempranamente. En general, el peso promedio de los ejemplares de T. infestans se mantuvo en valores próximos al inicial, mientras que en T. sordida se redujo. Los grupos gregarios se conformaron mayoritariamente en el sector inferior de la pared 1 (próximo al hospedador, observándose mayor nivel de contagio en T. infestans. A partir de los resultados obtenidos se formula la hipótesis de la superioridad competitiva en T. infestans.Para saber se algum tipo de interação se produzia entre populações de Triatoma infestans e T. sordida que conviviam em uma unidade experimental e compartilharam o mesmo recurso alimentar (ave, foi realizado estudo que abrangeu o período de setembro de 1988 a abril de 1989. A composição etária inicial para cada espécie foi: 27 N1, 7 N2, 11 N3, 3 N4, 8 N5, 4 machos e 10 fêmeas. A dinâmica da população, o estado nutricional, a predação e a conduta gregria foram estimados mediante censos mensais. T. infestans obteve maior êxito

Tratamentos focais e totais com inseticidas de ação residual para o controle de Triatoma brasiliensis e Triatoma pseudomaculata no Nordeste brasileiro Focal and total residual insecticide spraying to control Triatoma brasiliensis and Triatoma pseudomaculata in Northeast Brazil

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Alfredo M. Oliveira Filho

2000-01-01

Full Text Available Para controle eficiente dos triatomíneos Triatoma brasiliensis e Triatoma pseudomaculata, foi feito um ensaio de campo em Boa Viagem, Ceará, de modo a comparar a borrifação convencional versus tratamento focal com deltametrina 5% SC, dose 25 mg i.a./m² e o organofosforado malation lenta liberação 8.3% SR, dose 2g i.a./m². O ensaio incluiu aleatoriamente 1.541 casas, separadas em quatro grupos. Em dois deles foi aplicada borrifação focal ­ tratamento PT com deltametrina dentro das casas e no peridomicílio e PL que recebeu malation lenta liberação nas mesmas circunstâncias. Os outros dois tiveram tratamento convencional, isto é, aplicação total ­ PT com deltametrina no intra e peridomicílio e PL, tratado com deltametrina dentro das casas e malation lenta liberação no peridomicílio. As avaliações entomológicas aos 6 e 12 meses pós-tratamentos mostraram melhor resultado para o tratamento misto, grupo PL, provavelmente em decorrência da boa performance do piretróide dentro das casas e da formulação de lenta liberação nas condições hostis do peridomicílio. Os abrigos dos animais domésticos sofreram modificações ao longo do ano, colaborando com a redução da performance dos inseticidas no peridomicílio.To efficiently control the triatomines Triatoma brasiliensis and Triatoma pseudomaculata, a field trial was performed to compare conventional versus focal spraying of deltamethrin 5% SC at 25 mg a.i./m² and the slow-release organophosphate malathion 8.3% SR at 2g a.i./m². The assay took place in the county of Boa Viagem, Ceará State, with 1541 households, randomly separated into 4 groups. Two of them received focal spraying: PT, treated with deltamethrin indoors and in the peridomicile, and PL, which received slow-release malathion in the same circumstances. The other groups received conventional, i.e., total application: PT with deltamethrin in the intra- and peridomicile, and PL, which was treated with

Cytogenetics of Triatominae: III - A study on male sterility induced through hybridization of Triatoma sórdida and Triatoma pseudomaculata

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Giorgio Schreiber

1975-08-01

Full Text Available Males from bilateral crosses between Triatoma sórdida and Triatoma pseudomaculata were unable to give offspring, as shown by subsequent backcrosses (BC between hybrid males and parental females. This kind of sterility indueed through interspecific hybridization seems to be due to lack of sperm migration from the bursa copulatrix to the spermateca, thus suggesting primarily failure on the part of hybrid males to produce and/or to incorporate male accessory secretions into the spermatophore bulb. Addicional proof that sterility induced in hybrid males is at the sperm level has been afforded by the spermatogenesis herein studied. The anomalous processes like; 1 prophases of spermatogonia with the chromosomes scattered in the cytoplasm, 2 first metaphases with unpaired tetrades, 3 spermatids differing in size and 4 spermatozoa of abnormal shape and generdlly of giant size, can be taken as an indicator of the degree of departure from the normal course of spermatogenesis.

Cytogenetics of Triatominae: III - A study on male sterility induced through hybridization of Triatoma sórdida and Triatoma pseudomaculata

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Giorgio Schreiber

1975-08-01

Full Text Available Males from bilateral crosses between Triatoma sórdida and Triatoma pseudomaculata were unable to give offspring, as shown by subsequent backcrosses (BC between hybrid males and parental females. This kind of sterility indueed through interspecific hybridization seems to be due to lack of sperm migration from the bursa copulatrix to the spermateca, thus suggesting primarily failure on the part of hybrid males to produce and/or to incorporate male accessory secretions into the spermatophore bulb. Addicional proof that sterility induced in hybrid males is at the sperm level has been afforded by the spermatogenesis herein studied. The anomalous processes like; 1 prophases of spermatogonia with the chromosomes scattered in the cytoplasm, 2 first metaphases with unpaired tetrades, 3 spermatids differing in size and 4 spermatozoa of abnormal shape and generdlly of giant size, can be taken as an indicator of the degree of departure from the normal course of spermatogenesis.Os machos provenientes de cruzamentos bilaterais entre Triatoma sórdida e Triatoma pseudomaculata revelaram a incapacidade de produzir progênie, como se demonstra nos retrocruzamentos de machos híbridos com fêmeas das espécies paternas. Esta modalidade de esterilidade induzida através da hibridação interespecífica, parece ser devida à ausência de migração do esperma, determinada pela incapacidade dos híbridos machos produzirem a secreção opaca em suas glândulas acessórias e/ou incorporá-la à luz do espermatóforo. A prova adicional de que a incompatibilidade induzida em triatomíneos, através da hibridação inter específica, está no nível do esperma é fornecida pelo tipo anômalo de espermatogênese em híbridos aqui descrito, mostrando deste modo que: as prófases espermatogoniais têm os núcleos disruptos e os cromossomos espelhados no citoplasma. As primeiras metáfases meióticas têm as tétrades desemparelhadas. Os grupos de cromatídes assim obtidos

The rising importance of Triatoma rubrofasciata

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Jean-Pierre Dujardin

2015-05-01

Full Text Available The migration of invasive vector species has contributed to the worldwide extension of infectious diseases such as dengue (Aedes aegypti and chikungunya (Aedes albopictus. It is probably a similar behaviour for certain vectors of Chagas disease which allowed it to become a continental burden in Latin America. One of them, Triatoma rubrofasciata has also been spreading throughout the tropical and subtropical world. Here, the recent and massive peridomestic presence of T. rubrofasciata in Vietnam cities is reported, and tentatively explained, highlighting the need for improved entomological surveillance.

Using a Novel Evolutionary Algorithm to More Effectively Apply Community-Driven EcoHealth Interventions in Big Data with Application to Chagas Disease

Science.gov (United States)

Rizzo, D. M.; Hanley, J.; Monroy, C.; Rodas, A.; Stevens, L.; Dorn, P.

2016-12-01

Chagas disease is a deadly, neglected tropical disease that is endemic to every country in Central and South America. The principal insect vector of Chagas disease in Central America is Triatoma dimidiata. EcoHealth interventions are an environmentally friendly alternative that use local materials to lower household infestation, reduce the risk of infestation, and improve the quality of life. Our collaborators from La Universidad de San Carlos de Guatemala along with Ministry of Health Officials reach out to communities with high infestation and teach the community EcoHealth interventions. The process of identifying which interventions have the potential to be most effective as well as the houses that are most at risk is both expensive and time consuming. In order to better identify the risk factors associated with household infestation of T. dimidiata, a number of studies have conducted socioeconomic and entomologic surveys that contain numerous potential risk factors consisting of both nominal and ordinal data. Univariate logistic regression is one of the more popular methods for determining which risk factors are most closely associated with infestation. However, this tool has limitations, especially with the large amount and type of "Big Data" associated with our study sites (e.g., 5 villages comprise of socioeconomic, demographic, and entomologic data). The infestation of a household with T. dimidiata is a complex problem that is most likely not univariate in nature and is likely to contain higher order epistatic relationships that cannot be discovered using univariate logistic regression. Add to this, the problems raised with using p-values in traditional statistics. Also, our T. dimidiata infestation dataset is too large to exhaustively search. Therefore, we use a novel evolutionary algorithm to efficiently search for higher order interactions in surveys associated with households infested with T. dimidiata. In this study, we use our novel evolutionary

Phasing of the Triatoma virus diffraction data using a cryo-electron microscopy reconstruction

International Nuclear Information System (INIS)

Estrozi, L.F.; Neumann, E.; Squires, G.; Rozas-Dennis, G.; Costabel, M.; Rey, F.A.; Guerin, D.M.A.; Navaza, J.

2008-01-01

The blood-sucking reduviid bug Triatoma infestans, one of the most important vector of American human trypanosomiasis (Chagas disease) is infected by the Triatoma virus (TrV). TrV has been classified as a member of the Cripavirus genus (type cricket paralysis virus) in the Dicistroviridae family. This work presents the three-dimensional cryo-electron microscopy (cryo-EM) reconstruction of the TrV capsid at about 25 A resolution and its use as a template for phasing the available crystallographic data by the molecular replacement method. The main structural differences between the cryo-EM reconstruction of TrV and other two viruses, one from the same family, the cricket paralysis virus (CrPV) and the human rhinovirus 16 from the Picornaviridae family are presented and discussed

Comparative Meiotic Studies in Triatoma sordida (Stål and T. guasayana Wygodzinsky & Abalos (Reduviidae, Heteroptera

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P Rebagliati

1998-05-01

Full Text Available Triatoma sordida and T. guasayana are competent Trypanosoma cruzi vectors, with overlapping distribution areas in Argentina. Both species are morphologically similar, and their immature stages are hard to discriminate. Cytogenetic studies in the genus Triatoma reveal scarce karyotypic variations, being 2n= 20 + XY the most frequent diploid number in males. In the present work the meiotic behaviour of different Argentinian populations of T. sordida and T. guasayana has been analyzed; the meiotic karyotype of both species has also been compared. The species differ in total chromosome area and in the relative area of the sex chromosomes. These meiotic karyotypic differences constitute an additional tool for the taxonomic characterization of T. sordida and T. guasayana. The analysis of an interpopulation hybrid of T. sordida (Brazil x Argentina reveals a regular meiotic behaviour, despite the presence of heteromorphic bivalents. Our observations support the hypothesis that karyotype variations through the gain or loss of heterochromatin can not be considered as a primary mechanism of reproductive isolation in Triatoma.

Aspectos operacionais do controle do Triatoma brasiliensis

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Diotaiuti Liléia

2000-01-01

Full Text Available O controle de triatomíneos é dificultado pela capacidade de reinvasão das casas por exemplares silvestres. Entre agosto/96 e dezembro/97 realizou-se, no Ceará, um estudo a respeito da reinfestação das casas após borrifação. Das 277 Unidades Domiciliares ­ UD ­ pesquisadas, 40,8% estavam infestadas (21,7% dos intradomicílios e 35,4% dos peridomicílios. Dos 433 triatomíneos capturados, 207 eram Triatoma brasiliensis (48,8% no intradomicílio, média de 1,8 insetos/casa e 226 Triatoma pseudomaculata (97,3% no peridomicílio. Ocorre um único ciclo anual do T. brasiliensis, e dois ciclos anuais do T. pseudomaculata. Quatro meses após a borrifação, 9,7% das unidades domiciliares permaneciam positivas, principalmente no peridomicílio; 10,3% das UD foram positivas em todas as avaliações. O teste de suscetibilidade biológica à deltametrina revelou a persistência do inseticida no intradomicílio até nove meses após a borrifação. A prevalência global da infecção humana foi de 5,7%, tendo sido positivas cinco crianças menores de dez anos. Considerando-se a alta pressão de recolonização a partir de exemplares silvestres, propõe-se, como metodologia de controle, um sistema misto da avaliação tradicional e a vigilância epidemiológica.

Gene discovery in Triatoma infestans

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de Burgos Nelia

2011-03-01

Full Text Available Abstract Background Triatoma infestans is the most relevant vector of Chagas disease in the southern cone of South America. Since its genome has not yet been studied, sequencing of Expressed Sequence Tags (ESTs is one of the most powerful tools for efficiently identifying large numbers of expressed genes in this insect vector. Results In this work, we generated 826 ESTs, resulting in an increase of 47% in the number of ESTs available for T. infestans. These ESTs were assembled in 471 unique sequences, 151 of which represent 136 new genes for the Reduviidae family. Conclusions Among the putative new genes for the Reduviidae family, we identified and described an interesting subset of genes involved in development and reproduction, which constitute potential targets for insecticide development.

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

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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.

Existence of a sex pheromone in Triatoma infestans (Hemiptera: Reduvidae: II. Electrophysiological correlates

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Maria G. de Brito Sanchez

1995-10-01

Full Text Available The stimulus provided by a copulating pair of Triatoma infestans significantly affects the electrical activity of the nervous system of Triatoma infestans. Electrophysiological recordings were perfomed on stationary adult males presented with stimuli of an air current carrying odors from males, females, non-copulating pairs and mating pairs. The electrophysiological response was characterized by the low frequency occurrence of biphasic compound impulses. A significant increase in the frequency of the impulses occurred in stationary males when exposed to air currents of mating pairs, when compared to that evoked by a clean air stream. Analysis of the time course of the assays, showed that the electrophisiological activity during the copula was higher than prior to or after copula. The electrophysiological evidence presented here strongly supports the existence of pheromone(s released by one or both sexes during mating and which is perceived by male chemoreceptors located on the antennae.

Temperature effect upon blood consumption in Triatoma infestans

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Silvia Catalá

1992-12-01

Full Text Available Different blood consumption speed was observed in Triatoma infestans - nymphs and adults - exposed to 12 degrees C and 28 degrees C. Exposure to optimal temperature (28 degrees C allows the insects to consume blood at a rate of 9% per day. Significative relationship between blood amount present in the promesenteron and consumed blood was found at 28 degrees. Consumption of blood was drastically reduced at the lowest temperature. Accordingly, lack of ovaric development, oviposition and mating behaviour was observed in insects kept at 12 degrees C. Relationship between laboratory and field observations are discussed.

Description of a newly discovered Triatoma infestans (Hemiptera: Reduviidae Foci in Ibipeba, State of Bahia, Brazil

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Renato Freitas Araújo

2014-07-01

Full Text Available Introduction Chagas disease transmitted by the Triatoma infestans was eradicated from Brazil in 2006. However, reports of triatomine foci threaten the control of Chagas disease. The goal of this study was to determine T. infestans foci in the City of Ibipeba, State of Bahia. Methods Triatominae specimens were collected in Ibipeba and entomologic indicators were calculated using indices of domiciliary infestation, density, and colonization. Results T. infestans foci was discovery in Ibipeba, State of Bahia. Approximately 95% of the specimens were discovered inside dwellings, of which 34% were T. infestans. This species was also discovered forming a colony in tree bark in the peridomicile. Conclusions Triatoma infestans foci in peridomestic ecotopes in Ibipeba, BA, indicate increased the risk of transmission Chagas disease.

An Updated Insight into the Sialotranscriptome of Triatoma infestans: Developmental Stage and Geographic Variations

Czech Academy of Sciences Publication Activity Database

Schwarz, Alexandra; Medrano-Mercado, N.; Schaub, G. A.; Struchiner, C.J.; Bargues, M.D.; Levy, M.Z.; Ribeiro, J.M.C.

2014-01-01

Roč. 8, č. 12 (2014), e3372 ISSN 1935-2735 R&D Projects: GA MŠk LH12002 Institutional support: RVO:60077344 Keywords : Triatoma * Chagas disease * salivary gland Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 4.446, year: 2014

Hallazgo de Triatoma platensis Neiva, 1913 (Hemiptera, Triatominae en el estado brasileño de "Rio Grande do Sul" Finding of Triatoma platensis Neiva, 1913 (Hemiptera, Triatominae in the Brazilian State of "Rio Grande do Sul"

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Roberto Salvatella

1991-02-01

Full Text Available Triatoma platensis Neiva 1913 (Hemiptera, Triatominae, especie ornitófila, con área de dispersión conocida en Argentina, Bolivia, Paraguay y Uruguay es notificada en un primer registro para Brasil. Hallada en el municipio de Uruguaiana (Río Grande do Sul en nidos de Anumbius annumbi (Vieillot, 1817 (Passeriformes, Furnariidae donde cohabitaba con cricétidos de la especie Orizomys flavescens. Ningún ejemplar de los siete colectados se presentó infectado por Trypanosoma cruzi.Triatoma platensis, an ornitophilic species, found in Argentina, Bolivia, Paraguay and Uruguay is reported for the first time in Brazil. It was found in the county of Uruguaiana (Rio Grande do Sul in nests of Anumbius annumbi (Vieillot, 1817 (Passeriformes, Furnariidae where it cohabited with cricetids belonging to the species Orizomys flavescens. None of the seven individuals collected were infected by Trypanosoma cruzi.

Feeding and defaecation patterns in Triatoma sordida

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LB Crocco

1996-08-01

Full Text Available Triatoma sordida is a peridomestic Triatominae that could play an important role in the transmission of Trypanosoma cruzi, although its vectorial competence is not well known. The aim of this work was to evaluate two aspects of the vectorial competence: the feeding behaviour and defaecation patterns, and to compare them with T. infestans. The feeding and defaecation patterns were studied in adults and fifth instar nymphs of T. sordida fed ad libitum on a restrained pigeon. The results showed how the blood meal size controls excretion behaviour. Blood intake and time to first defaecation showed a significant negative correlation. Adults and nymphs frequently defaecated during the blood meal, reaching the maximum frequency within the first 10 minutes.

A new tactic for Triatoma infestans control: fabrics impregnated with beta-cypermethrin Telas impregnadas de beta-cipermetrina: una nueva táctica para el control de Triatoma infestans

OpenAIRE

Edgardo Wood; Susana A. de Licastro; Norma Casabé; María Inés Picollo; Raúl Alzogaray; Eduardo Nicolás Zerba

1999-01-01

Triatoma infestans is the most important vector of Chagas’ disease in Argentina. Experiences from Argentine national campaigns have shown indoor spraying to control triatomine bugs is both expensive and difficult. An alternative control method may be the use of pyrethroid- impregnated fabrics (PIFs), which could be both a practical and cheap complement to conventional control measures. In this study, a formulation of emulsifiable concentrate of beta-cypermethrin [a-cyano-3-phenoxybenzyl-...

Kissing Bug (Triatoma spp.) Intrusion into Homes: Troublesome Bites and Domiciliation.

Science.gov (United States)

Klotz, Stephen A; Shirazi, F Mazda; Boesen, Keith; Beatty, Norman L; Dorn, Patricia L; Smith, Shannon; Schmidt, Justin O

2016-01-01

Kissing bugs (Triatoma spp.) frequently enter homes and bite human and pet occupants. Bites may lead to severe allergic reactions and, in some cases, death. Kissing bugs are also vectors of Trypanosoma cruzi, the cause of Chagas disease. In general, modern houses in the United States are not conducive to domiciliation of kissing bugs (bugs living out their entire life within the home with the presence of eggs, nymphs, adults, and exuviae). Construction features such as concrete foundations, solid walls and ceilings, window screens, tight thresholds for doors and windows, and other measures impede bug entry into homes, and air conditioning reduces the need for open doors and windows. Where Chagas disease is endemic in Mexico and Central and South America, homes often have thatch roofs, adobe walls, and open doors and windows. We investigated numerous instances of kissing bug intrusions into homes in Southern Arizona, California, and Louisiana and documented the reactions to kissing bug bites. Our work confirms the importance of modern home construction in limiting kissing bug intrusions. Older homes, especially those lacking modern screening, caulking, and weather stripping to reduce air leakage, may be subject to kissing bug intrusions and domiciliation. We describe a community in Southern Arizona where domiciliation of homes by Triatoma recurva is common. We also provide recent data regarding kissing bug bites and allergic reactions to the bites.

Towards an indigenous dwelling that limits the domestic infestation by Triatoma infestans

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Maria Auxiliadora Arrom

2017-01-01

Full Text Available Introduction: The Paraguayan State has a pending debt with indigenous people regarding public policies to combat extreme poverty, in addition to serious health problems, such as Chagas disease with Triatoma infestans as its vector. Objective: To determine the characteristics of an improved dwelling that limits the domestic infestation by Triatoma infestans from the indigenous perspective. Methodology: A descriptive study with a quantitative and qualitative approach was conducted. The instruments of data collection were: household survey, focus groups, and in-depth interviews with key actors. Results: Household heads of 270 dwelling were surveyed, of which 85% (230 had nonresistant or solid or waste materials in at least one of the components or at all. 86.3% (233 of the heads of household indicated that they wanted to improve them, and the lack of sufficient income for the household could be considered the main limitation. Conclusions: When projecting graphically the ideal or improved housing, from their perspective, the studied indigenous families showed that the housing of the Mennonites and the so-called Paraguayans (non-indigenous Paraguayan population inhabiting the same area gathered the physical characteristics that set the boundaries to limit the accommodation of the vector, and were adequate for the environment.

Tratamentos focais e totais com inseticidas de ação residual para o controle de Triatoma brasiliensis e Triatoma pseudomaculata no Nordeste brasileiro

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Alfredo M. Oliveira Filho

2000-01-01

Full Text Available Para controle eficiente dos triatomíneos Triatoma brasiliensis e Triatoma pseudomaculata, foi feito um ensaio de campo em Boa Viagem, Ceará, de modo a comparar a borrifação convencional versus tratamento focal com deltametrina 5% SC, dose 25 mg i.a./m² e o organofosforado malation lenta liberação 8.3% SR, dose 2g i.a./m². O ensaio incluiu aleatoriamente 1.541 casas, separadas em quatro grupos. Em dois deles foi aplicada borrifação focal ­ tratamento PT com deltametrina dentro das casas e no peridomicílio e PL que recebeu malation lenta liberação nas mesmas circunstâncias. Os outros dois tiveram tratamento convencional, isto é, aplicação total ­ PT com deltametrina no intra e peridomicílio e PL, tratado com deltametrina dentro das casas e malation lenta liberação no peridomicílio. As avaliações entomológicas aos 6 e 12 meses pós-tratamentos mostraram melhor resultado para o tratamento misto, grupo PL, provavelmente em decorrência da boa performance do piretróide dentro das casas e da formulação de lenta liberação nas condições hostis do peridomicílio. Os abrigos dos animais domésticos sofreram modificações ao longo do ano, colaborando com a redução da performance dos inseticidas no peridomicílio.

[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.

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.

Triatoma rubrovaria (Blanchard 1843: tábua de vida das ninfas, duração das formas e oviposição das fêmeas Triatoma rubrovaria (Blanchard 1843: life table of nymphs, duration of the forms and posture of the females

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Vera Lúcia Cortiço Corrêa Rodrigues

2005-05-01

Full Text Available Os autores acompanharam a evolução de 150 ovos de Triatoma rubrovaria o que permitiu a construção de uma tábua de sobrevida das ninfas. A forma alada foi atingida por 94,64% dos exemplares, sendo 79 deles machos e 65 fêmeas. O tempo médio dos alados machos foi de 115 dias e das fêmeas, 99 dias. Parte desses exemplares formaram 30 casais, mantidos isolados, o que possibilitou o levantamento da postura de cada fêmea. Outro lote, também formado por 30 machos e 30 fêmeas, foi mantido em um único cristalizador de vidro, o que permitiu constatar sua maior postura (7.832 ovos em relação aquela das fêmeas acasaladas por único macho (5.167. O bom desenvolvimento dos exemplares no processo de evolução e de reprodução da espécie, nas condições do experimento, mostrou a boa capacidade de manutenção das colônias do Triatoma rubrovaria, em condições de laboratório.The authors followed the development of 150 eggs of Triatoma rubrovaria to enable the construction of a life table for the nymphs. The winged form was reached by 94.64% of the individuals, of which 79 were males and 65 females. The mean lifetime of the males was 115 days and 99 days for the females. Part of this group was divided into 30 couples and kept separated to facilitate the count of egg laying by each female. Another lot was also formed of 30 males and 30 females but these were housed together in a glass crystallizer that allowed the observation of a larger number of eggs laid (7,832 eggs in relationship to that of the females with only one male (total 5,167 eggs. The good development of the individuals and reproduction of the species in the experimental conditions demonstrated the capacity to maintain colonies of Triatoma rubrovaria in laboratory conditions.

The role of dirt floors and of firewood in rural dwellings in the epidemiology of Chagas' disease in Costa Rica.

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Zeledón, R; Vargas, L G

1984-03-01

In an endemic area of Chagas' disease in Costa Rica, 50 houses infested with Triatoma dimidiata were re-examined after a period of 14-17 years. Criteria used were two socioeconomic parameters which are closely associated with the presence of the bugs: colonies of triatomines inside houses are favored by the presence of a dirt floor, and stored firewood is an excellent refuge for insects outdoors. Indoor infestation was completely eliminated from nine of 13 houses in which the floors had been changed from dirt to concrete during this period, and nearly eliminated from the other four, supporting the hypothesis that the disappearance of dirt floors makes it difficult for the bugs to thrive inside houses. Of the 21 houses that lost the infestation (inside, outside, or both), firewood had been eliminated in 13, and of 29 houses that remained infested firewood had been eliminated in only two. An inverse relationship was found between distance of firewood piles from the house and presence of bugs. It is supposed that a colony of insects frequently starts in stored firewood and then moves into the household if a dirt floor is present. Removal of firewood and replacement of dirt floors by concrete would provide good prophylactic measures against the transmission of Chagas' disease in areas where T. dimidiata is the vector.

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.

Population structure of the Chagas disease vector, Triatoma infestans, at the urban-rural interface

OpenAIRE

Foley, Erica A.; Khatchikian, Camilo E.; Hwang, Josephine; Ancca-Juárez, Jenny; Borrini-Mayori, Katty; Quıspe-Machaca, Victor R.; Levy, Michael Z.; Brisson, Dustin

2013-01-01

The increasing rate of biological invasions resulting from human transport or human-mediated changes to the environment have had devastating ecologic and public health consequences. The kissing bug, Triatoma infestans, has dispersed through the Peruvian city of Arequipa. The biological invasion of this insect has resulted in a public health crisis, putting thousands of residents of this city at risk of infection by Trypanosoma cruzi and subsequent development of Chagas disease. Here we show t...

Ecotopes, Natural Infection and Trophic Resources of Triatoma brasiliensis (Hemiptera, Reduviidae, Triatominae

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Jane Costa

1998-01-01

Full Text Available Triatoma brasiliensis is considered as one of the most important Chagas disease vectors in the northeastern Brazil. This species presents chromatic variations which led to descriptions of subspecies, synonymized by Lent and Wygodzinsky (1979. In order to broaden bionomic knowledge of these distinct colour patterns of T. brasiliensis, captures were performed at different sites, where the chromatic patterns were described: Caicó, Rio Grande do Norte (T. brasiliensis brasiliensis Neiva, 1911, it will be called the "brasiliensis population"; Espinosa, Minas Gerais (T. brasiliensis melanica Neiva & Lent 1941, the "melanica population" and Petrolina, Pernambuco (T. brasiliensis macromelasoma, Galvão 1956, the "macromelasoma population". A fourth chromatic pattern was collected in Juazeiro, Bahia the darker one in overall cuticle coloration, the "Juazeiro population". At the sites of Caicó, Petrolina and Juazeiro, specimens were captured in peridomiciliar ecotopes and in wilderness. In Espinosa the specimens were collected only in wilderness, even though several exhaustive captures have been performed in peridomicile at different sites of this municipality. A total of 298 specimens were captured. The average registered infection rate was 15% for "brasiliensis population" and of 6.6% for "melanica population". Specimens of "macromelasoma" and of "Juazeiro populations" did not present natural infection. Concerning trophic resources, evaluated by the precipitin test, feeding eclecticism for the different colour patterns studied was observed, with dominance of goat blood in household surroundings as well as in wilderness

Urban ecology of Triatoma infestans in San Juan, Argentina.

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Vallvé, S L; Rojo, H; Wisnivesky-Colli, C

1996-01-01

This study was performed in an urban neighborhood of the capital city of the province of San Juan, Argentina. Erected as a housing complex, the place consists of 768 flats distributed in buildings of three and seven floors each. A survey was carried out in 33% of the dwellings, enquiring about the number of Triatoma infestans found indoors, stage of the bug development-nymph or adult- and how these insects had entered their homes. Adult T.infestans were found on all floors; 163 people (64%) had found them at least once, and 130 (51%) several times. Dispersal flight seems to have been the main mechanism of infestation by adult bugs in this area, and a total of 51% of the surveyed inhabitants reported that the insects had flown into their flats.

Urban ecology of Triatoma infestans in San Juan, Argentina

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Silvana L Vallvé

1996-08-01

Full Text Available This study was performed in an urban neighborhood of the capital city of the province of San Juan, Argentina. Erected as a housing complex, the place consists of 768 flats distributed in buildings of three and seven floors each. A survey was carried out in 33% of the dwellings, enquiring about the number of Triatoma infestans found indoors, stage of the bug development - nymph or adult - and how these insects had entered their homes. Adult T.infestans were found on all floors; 163 people (64% had found them at least once, and 130 (51% several times. Dispersal flight seems to have been the main mechanism of infestation by adult bugs in this area, and a total of 51% of the surveyed inhabitants reported that the insects had flown into their flats.

Fungal flora of the digestive tract of Triatoma infestans (Hemiptera: Reduviidae from Argentina Flora fúngica de tractos digestivos en Triatoma infestans (Hemiptera: Reduviidae en Argentina

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G. A. Marti

Full Text Available A survey of the fungal microbiota of the digestive tract of Triatoma infestans (Klug (Hemiptera: Reduviidae adults was carried out. Insects captured in the field from different provinces in Argentina, as well as individuals reared in artificial colonies, were used for dissection. Axenic cultures of the fungal species were identified and were deposited with mycological collections at La Plata , Argentina. A total of 33 fungal species, with the exception of three that were mycelia sterilia, belonging to 11 genera were identified. Thirty two species belonged to Ascomycota (Eurotiomycetes and Sordariomycetes and one to Zygomycota (Zygomycetes. The genera with the greatest number of species were Penicillium (15, Aspergillus (5, and Cladosporium (2. Among the isolated fungi, some of the species were entomopathogenic or pathogens of humans and other animals.En el presente estudio se realizó un relevamiento de la flora fúngica microbiana en tractos digestivos de adultos de Triatoma infestans (Klug (Hemiptera: Reduviidae. Se disecaron insectos capturados del campo en diferentes provincias Argentinas, así como también se utilizaron individuos de una colonia artificial. Fueron realizados cultivos axénicos de las especies fúngicas aisladas, los que fueron identificados y luego depositados en las colecciones de hongos entomopatógenos del CEPAVE La Plata , Argentina. Fueron identificadas 33 especies fúngicas perteneciente a 11 géneros. Treinta y dos especies pertenecen a Ascomycota (Eurotiomycetes y Sordariomycetes y una a Zygomycota (Zygomycetes. Los géneros con mayor número de especies fueron Penicillium (15, Aspergillus (5, y Cladosporium (2. Entre los aislamientos fúngicos, algunas de las especies encontradas son entomopatogénicas o patógenas de humanos y otros animales.

Cutaneous allergic reactions to Triatoma infestans after xenodiagnosis Reações cutâneas alérgicas ao Triatoma infestans após Xenodiagnóstico

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Kenneth E. Mott

1980-12-01

Full Text Available We determined the frequency of cutaneous allergic reactions to bites of Triatoma infestans during xenodiagnosis in a rural community where Panstrongylus megistrus is the only domestic vector of Trypanosoma cruzi. Localized urticaria or more intense cutaneous allergic reactions at 48 and 72 hours were observed in 86.7% and 82.1% respectively of the individuals in our study. Urticaria was more severe in children and older adults and in women than in men. The high frequency of reactions suggests either cutaneous reactivity to T. infestans without prior sensitization or cross reactivity between P. megistus and T. infestans. A single application of topical corticosteroid or antihistamine medication did not reduce the cutaneous reactions.A freqüência de reações cutâneas alérgicas ás picadas de Triatoma infestans após xenodiagnóstico foi determinada numa comunidade rural na qual Panstrongylus megistus é o único vetor doméstico. Urticária focal ou reações cutâneas alérgicas mais intensas foram observadas em 86.7% e em 82.1% dos participantes estudados, respectivamente ás 48 e ás 72 horas. A urticária foi mais severa em crianças e adultos idosos e mais severa em mulheres do que em homens. A alta freqüência das reações sugere a existência de reatividade cutânea ao T. infestans, sem prévia sensibilização, ou uma reatividade cruzada entre P. megistus e T. infestans. A aplicação tópica de pomada de corticosteróide ou de anti-histamínico não reduziu as reações cutâneas alérgicas.

Phylogeny and niche conservatism in North and Central American triatomine bugs (Hemiptera: Reduviidae: Triatominae), vectors of Chagas' disease.

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Ibarra-Cerdeña, Carlos N; Zaldívar-Riverón, Alejandro; Peterson, A Townsend; Sánchez-Cordero, Víctor; Ramsey, Janine M

2014-10-01

The niche conservatism hypothesis states that related species diverge in niche characteristics at lower rates than expected, given their lineage divergence. Here we analyze whether niche conservatism is a common pattern among vector species (Hemiptera: Reduviidae: Triatominae) of Trypanosoma cruzi that inhabit North and Central America, a highly heterogeneous landmass in terms of environmental gradients. Mitochondrial and nuclear loci were used in a multi-locus phylogenetic framework to reconstruct phylogenetic relationships among species and estimate time of divergence of selected clades to draw biogeographic inferences. Then, we estimated similarity between the ecological niche of sister species and tested the niche conservatism hypothesis using our best estimate of phylogeny. Triatoma is not monophyletic. A primary clade with all North and Central American (NCA) triatomine species from the genera Triatoma, Dipetalogaster, and Panstrongylus, was consistently recovered. Nearctic species within the NCA clade (T. p. protracta, T. r. rubida) diverged during the Pliocene, whereas the Neotropical species (T. phyllosoma, T. longipennis, T. dimidiata complex) are estimated to have diverged more recently, during the Pleistocene. The hypothesis of niche conservatism could not be rejected for any of six sister species pairs. Niche similarity between sister species best fits a retention model. While this framework is used here to infer niche evolution, it has a direct impact on spatial vector dynamics driven by human population movements, expansion of transportation networks and climate change scenarios.

Presence of Triatominae (Hemiptera, Reduviidae and Risk of Transmission of Chagas Disease in Colima, México

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Espinoza-Gómez Francisco

2002-01-01

Full Text Available With the purpose of evaluating the risk of transmission of the Chagas disease in the State of Colima, México, an entomological survey was performed to obtain triatominae and the rate of infection by Trypanosoma cruzi determined by examination of its dejections. Two hundred eighteen houses located in 16 villages were sampled. In each house the intradomestic and peridomestic habitats were examined by the man-hour-house method, sensor boxes and mouse-baited traps. Also, 12 silvatic places were explored around the same areas using the same techniques as the ones sampled. In total, 456 specimens were captured, of which 139 correspond to Triatoma phyllosoma pallidipennis; 80 to T. p. longipennis; one specimen of T. dimidiata and 236 nymphs of Triatoma sp. Two hundred ninety seven insects were captured in the intradomestic habitat, 132 in the peridomestic and 26 in the silvatic. The index of positive houses was 27%, located in the central area of the state. The rate of natural infection with T. cruzi showed 25.6%. This results confirmed the presence of two important vectors of the Chagas disease in Colima. Its preference for the domestic habitat and its high levels of natural infection with T. cruzi suggested the existence of a significant risk for its transmission in this area of the country.

Flight Muscle Dimorphism and Heterogeneity in Flight Initiation of Field-Collected Triatoma infestans (Hemiptera: Reduviidae)

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Gurevitz, Juan M.; Kitron, Uriel; Gürtler, Ricardo E.

2007-01-01

Recent experiments demonstrated that most field-collected Triatoma infestans (Klug) (Hemiptera: Reduviidae) adults from northern Argentina either never initiated flight or did so repeatedly in both sexes. This pattern could not be explained by sex, adult age, weight, weight-to-length ratio (W/L), or chance. We examined whether bugs that never initiated flight possessed developed flight muscles, and whether flight muscle mass relative to total body mass (FMR) was related to the probability of ...

A new tactic for Triatoma infestans control: fabrics impregnated with beta-cypermethrin Telas impregnadas de beta-cipermetrina: una nueva táctica para el control de Triatoma infestans

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Edgardo Wood

1999-07-01

Full Text Available Triatoma infestans is the most important vector of Chagas’ disease in Argentina. Experiences from Argentine national campaigns have shown indoor spraying to control triatomine bugs is both expensive and difficult. An alternative control method may be the use of pyrethroid- impregnated fabrics (PIFs, which could be both a practical and cheap complement to conventional control measures. In this study, a formulation of emulsifiable concentrate of beta-cypermethrin [a-cyano-3-phenoxybenzyl-3- (2,2-dichlorovinyl -2,2-dimethylcyclopropanecarboxilate] pyrethroid was used to impregnate different fabrics. The fabrics were then tested for their efficacy and persistence in killing Triatoma infestans. Insects attempting to penetrate or grasp the fabric in search of blood meals were poisoned by the exposure to the absorbed pyrethroid. Laboratory bioassays showed that the insecticidal effect of the PIFs with a dosage of 0.2 g/m² lasted longer on wool than on cotton or rayon. Eight months after impregnation, a residual efficacy of 100% was found for wool, 80% for rayon-cotton fabrics, and 50% for rayon- polyester fabrics. In addition, beta-cypermethrin-impregnated fabrics showed a better repellency effect than did fabrics impregnated with either deltamethrin or cypermethrin. For field trials, fabrics were impregnated either in the laboratory or "in situ" at a dosage of 1 g beta-cypermethrin/m² and then dried. The PIFs were placed inside homes, either under the roof or under the bed mattress. The field trials showed the PIF approach to be very effective in keeping dwellings free of triatomine bugs for at least one year and found a high degree of acceptability among the houses’ residents.Triatoma infestans es el principal vector de la enfermedad de Chagas en Argentina. La experiencia adquirida en las campañas nacionales de este país ha demostrado que la fumigación de los domicilios para controlar los triatómidos es cara y difícil. Un método de control

Ecohealth Interventions Limit Triatomine Reinfestation following Insecticide Spraying in La Brea, Guatemala

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Lucero, David E.; Morrissey, Leslie A.; Rizzo, Donna M.; Rodas, Antonieta; Garnica, Roberto; Stevens, Lori; Bustamante, Dulce M.; Monroy, Maria Carlota

2013-01-01

In this study, we evaluate the effect of participatory Ecohealth interventions on domestic reinfestation of the Chagas disease vector Triatoma dimidiata after village-wide suppression of the vector population using a residual insecticide. The study was conducted in the rural community of La Brea, Guatemala between 2002 and 2009 where vector infestation was analyzed within a spatial data framework based on entomological and socio-economic surveys of homesteads within the village. Participatory interventions focused on community awareness and low-cost home improvements using local materials to limit areas of refuge and alternative blood meals for the vector within the home, and potential shelter for the vector outside the home. As a result, domestic infestation was maintained at ≤ 3% and peridomestic infestation at ≤ 2% for 5 years beyond the last insecticide spraying, in sharp contrast to the rapid reinfestation experienced in earlier insecticide only interventions. PMID:23382173

Triatoma rubrovaria (Blanchard, 1843 (Hemiptera, Reduviidae, Triatominae II: trophic resources and ecological observations of five populations collected in the State of Rio Grande do Sul, Brazil

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Almeida Carlos Eduardo

2002-01-01

Full Text Available Triatoma rubrovaria has become the most frequently captured triatomine species after the control of T. infestans in the State of Rio Grande do Sul (RS, Brazil. Isoenzymatic and chromatic studies indicate the existence of, at least, two distinct phenotypic patterns of T. rubrovaria in RS. The geographic variation noted through molecular tools may also result in distinct profiles of vectorial potentiality. In order to enhance our understanding of the bionomic knowledge of T. rubrovaria separate batches of the species were collected from different municipalities of RS distant from 72 to 332 km: Santana do Livramento (natural ecotope, Santana do Livramento (artificial ecotope, Santiago (natural ecotope, Canguçu (peridomicile and Encruzilhada do Sul (natural ecotope. A total of 285 specimens were collected, 85 specimens kept sufficient fecal material in their guts for the precipitin analysis. The results indicated the food eclecticism for this species and the anti-rodent serum showed the highest positivity in most localities. From the total of analyzed samples, only 1.3% of unique positivity for human blood was registered, all of them for Santiago population. This reactivity to human blood may be associated to pastures activities in the field.

Distribución Espacial de Vectores de la Enfermedad de Chagas en el Estado de Guanajuato 1998-2000 Distribución Espacial de Vectores de la Enfermedad de Chagas en el Estado de Guanajuato 1998-2000

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Francisco Ernesto González Bravo

2012-02-01

Full Text Available El presente estudio se realizó con la finalidad de llevar a cabo la verificación de la existencia y la ubicación de los vectores de la enfermedad de Chagas en los municipios del Estado de Guanajuato y a través de esto, delimitar áreas de distribución espacial de las especies dentro de este territorio, contribuyendo así, a establecer zonas de riesgo y al determinar la infección del Trypanosoma cruzi en los vectores, se conocerá el riesgo para la población humana. Esta investigación se realizó a través de la información del envío etiquetado de triatominos obtenidos por personal de campo de la Secretaría de Salud de Guanajuato y enviados para su clasificación taxonómica al Laboratorio Estatal de Salud Pública del mismo estado. Se recabó información de tres años (1998 - 2000 de los municipios donde se encuentran brigadas de trabajo y la ausencia reportada de vectores en algunos de ellos, probablemente se debe a la falta de búsqueda en los mismos. No se realizó el índice de infestación de vectores debido a que el método de búsqueda no tuvo la misma intensidad en todo el territorio, ni el método de muestreo lo permitió; sólo se estableció la localización de cada una de las especies según el área de donde fue colectada. Se encontraron 5 especies de triatominos: Triatoma mexicana, T. barberi, T. longipennis, T. pallidipennis y T. dimidiata, en 162 localidades de 25 municipios del estado; en alturas que fluctuaron desde los 870 metros sobre el nivel del mar (m.s.n.m., hasta los 2200. El sitio donde se encontró a los vectores con más frecuencia fue para T. mexicana, intradomicilio; T. barberi, corral; T. longipennis, intradomicilio; T. pallidipennis, intradomicilio; ninfas, intradomicilio y T. dimidiata que se colectó en una única ocasión, no reportó sitio de colecta. This study has been perfomed in order to verify the existence and location of vectors of Chagas disease in the entities of Guanajuato state to limit

A new endemic focus of Chagas disease in the northern region of Veraguas Province, Western Half Panama, Central America.

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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.

Aspectos ecológicos da Tripanossomíase americana: VI - Persistência do Triatoma sordida apósalteração ambiental e suas possíveis relações com a dispersão da espécie Ecological aspects of South American trypanosomiasis: VI. Permanence of Triatoma sordida after environmental alteration and its possibles relation to dispersion

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Oswaldo Paulo Forattini

1974-09-01

Full Text Available São relatadas as observações sobre a persistência do Triatoma sordida em área onde foi procedida alteração temporária da cobertura vegetal. Os resultados obtidos demonstram a capacidade de resistência do triatomíneo a esse fator. Procurou-se relacionar esse aspecto à distribuição da espécie no Estado de São Paulo, Brasil. Existe certa semelhança entre os dados disponíveis a esse respeito e a evolução da atividade agrícola na região. Finalmente são considerados também os aspectos climáticos que podem influir na dispersão da espécie.Studies about permanence of Triatoma sordida after temporary alteration of the local vegetation are related. Results reached showed a bug resistence to the devastation of shrubby vegetation by fire. An attempt is made for to relate this particular aspect with species distribution in the S. Paulo State, Brazil. There are some analogies between the available data about this and the development of agrarian activities. Beside the climatic one, this factor may be considered as favorable to the Triatoma sordida dispersion, by the natural environmental alteration who if follows.

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

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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.

Primer registro de Triatoma infestans (Klug (Hemiptera: Reduviidae asociado a nidos de loros barranqueros (Cyanoliseus patagonus (Aves: Psittacidae

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María L. HERNÁNDEZ

2015-01-01

Full Text Available Triatoma infestans es el vector más importante de la enfermedad de Chagas de la Argentina. Se cita por primera vez la presencia de T. infestans (Klug (Hemiptera: Reduviidae asociado a nidos de loro barranquero Cyanoliseus patagonus (Psittasiformes: Psittacidae construidos en viviendas de adobe abandonadas. Se discuten las posibles implicancias de este hallazgo para la vigilancia entomológica del vector.

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.

Structure of the Triatoma virus capsid.

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Squires, Gaëlle; Pous, Joan; Agirre, Jon; Rozas-Dennis, Gabriela S; Costabel, Marcelo D; Marti, Gerardo A; Navaza, Jorge; Bressanelli, Stéphane; Guérin, Diego M A; Rey, Felix A

2013-06-01

The members of the Dicistroviridae family are non-enveloped positive-sense single-stranded RNA (+ssRNA) viruses pathogenic to beneficial arthropods as well as insect pests of medical importance. Triatoma virus (TrV), a member of this family, infects several species of triatomine insects (popularly named kissing bugs), which are vectors for human trypanosomiasis, more commonly known as Chagas disease. The potential use of dicistroviruses as biological control agents has drawn considerable attention in the past decade, and several viruses of this family have been identified, with their targets covering honey bees, aphids and field crickets, among others. Here, the crystal structure of the TrV capsid at 2.5 Å resolution is reported, showing that as expected it is very similar to that of Cricket paralysis virus (CrPV). Nevertheless, a number of distinguishing structural features support the introduction of a new genus (Triatovirus; type species TrV) under the Dicistroviridae family. The most striking differences are the absence of icosahedrally ordered VP4 within the infectious particle and the presence of prominent projections that surround the fivefold axis. Furthermore, the structure identifies a second putative autoproteolytic DDF motif in protein VP3, in addition to the conserved one in VP1 which is believed to be responsible for VP0 cleavage during capsid maturation. The potential meaning of these new findings is discussed.

Genetic Characterization of Trypanosoma cruzi DTUs in Wild Triatoma infestans from Bolivia: Predominance of TcI

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Brenière, Simone Frédérique; Aliaga, Claudia; Waleckx, Etienne; Buitrago, Rosio; Salas, Renata; Barnabé, Christian; Tibayrenc, Michel; Noireau, François

2012-01-01

Background The current persistence of Triatoma infestans (one of the main vectors of Chagas disease) in some domestic areas could be related to re-colonization by wild populations which are increasingly reported. However, the infection rate and the genetic characterization of the Trypanosoma cruzi strains infecting these populations are very limited. Methodology/Principal Findings Of 333 wild Triatoma infestans specimens collected from north to south of a Chagas disease endemic area in Bolivia, we characterized 234 stocks of Trypanosoma cruzi using mini-exon multiplex PCR (MMPCR) and sequencing the glucose phosphate isomerase (Gpi) gene. Of the six genetic lineages (“discrete typing units”; DTU) (TcI-VI) presently recognized in T. cruzi, TcI (99.1%) was overdominant on TcIII (0.9%) in wild Andean T. infestans, which presented a 71.7% infection rate as evaluated by microscopy. In the lowlands (Bolivian Chaco), 17 “dark morph” T. infestans were analyzed. None of them were positive for parasites after microscopic examination, although one TcI stock and one TcII stock were identified using MMPCR and sequencing. Conclusions/Significance By exploring large-scale DTUs that infect the wild populations of T. infestans, this study opens the discussion on the origin of TcI and TcV DTUs that are predominant in domestic Bolivian cycles. PMID:22685616

Morphological Studies on the Triatoma brasiliensis Neiva, 1911 (Hemiptera, Reduviidae, Triatominae Genital Structures and Eggs of Different Chromatic Forms

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Jane Costa

1997-07-01

Full Text Available Triatoma brasiliensis is considered one of the most important Chagas disease vectors being a widespread species in semiarid areas of northeastern Brazil. The species displays distinct chromatic patterns of the cuticle in different localities. Four populations were analyzed in this study: 1-Caicó, Rio Grande do Norte, it will be called the brasiliensis population; 2-Espinosa, Minas Gerais, the melanica population; 3-Petrolina, Pernambuco, the macromelasoma population, and 4-Juazeiro, Bahia, the darker one in overall cuticle coloration, the Juazeiro population. In order to differentiate the four populations of T. brasiliensis, a comparative morphological analysis of external genital structures and of eggs were carried out. The analysis of the male genital structures evidenced minor individual structural variations that did not correlate with chromatic differences or the geographical origins, emphasizing the importance of examining sufficiently large and representative samples before using minor genital variations for taxonomic diagnosis. By scanning electron microscopy of the egg exochorion, each chromatic population presented a distinct ornamentation pattern. The melanica population differed mainly from the other populations studied since it had about 40.6%, 69.6% and 76.6% more perforations, on each cell exochorion, than the brasiliensis, the Juazeiro and the macromelasoma populations respectively. In the melanica population the perforation layout is also peculiar, with densely distributed perforations over all the egg surface. Morphometric measures of the eggs showed statistically significant differences: the macromelasoma population presented the longest length (2.43 mm while the shortest was recorded in the brasiliensis population (2.29 mm.

Sobrevivência e ocorrência de muda em Triatoma infestans Klug (Hemiptera, Reduviidae após choque de temperatura Survival and molting occurrence in Triatoma infestans Klug (Hemiptera, Reduviidae after temperature shocks

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Vera Lúcia C.C. Rodrigues

1991-12-01

Full Text Available A sobrevivência e a ocorrência de mudas em espécimes de Triatoma infestans foram estudados num período de 30 dias após choques de temperatura. Foi demonstrado que choques hipertérmico e hipotérmico interferem nesses processos, na dependência da temperatura do choque, tempo de sua duração, fase de desenvolvimento e sexo dos espécimes. Dentre as situações experimentais utilizadas, o choque a 0°C por 12 h pareceu produzir a ação mais deletéria, porém choques a 40°C e 0°C mesmo por uma hora são admitidos como afetando o desenvolvimento hormonal que controla a muda. Casos de aumento de sobrevivência pós-choque são sugeridos como tendo sido favorecidos por ação de proteínas de choque térmico.Survival and molting occurrence were studied in specimens of Triatoma infestans over 30 days after temperature shocks. Hyperthermal and hypotermal shocks could be found to affect both survival and molting incidence as a function of temperature and period of the developement phase and sex of the specimens. Considering the various test conditions, the shock at 0°C for 12 h was found to elicit the most deleterious effect, whereas shocks at 40°C and 0°C even for 1 h are interpreted as affecting the hormonal balance which controls molting. Cases of a rise in post-shock survival are suggested to have been favored by heat-shock protein action.

Variations of the External Male Genitalia in Three Populations of Triatoma infestans Klug, 1834

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Pires Herton Helder Rocha

1998-01-01

Full Text Available Triatoma infestans is the triatomine that presents the greatest dispersion area in South America. However, it is not known whether the original characteristics of this insect remained in its long dispersion process. The purpose of this work was to study comparatively the external male genitalia of insects from different populations of T. infestans, two from Brazil (Minas Gerais and Bahia and one from Bolivia (Cochabamba Valley, and to investigate the correlation between the morphological and behavioral variations. Differences were observed in one of the structures of the external genitalia (endosoma process that could be used to characterize the insects from the three populations studied.

Estadísticos poblacionales de Triatoma rubrovaria en condiciones de laboratorio Population statistics of Triatoma rubrovaria in laboratory

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Elena B Oscherov

2005-04-01

Full Text Available OBJETIVO: Obtener parámetros poblacionales de T. rubrovaria a fin de caracterizar demográficamente a esta especie. MÉTODOS: La investigación se realizó entre octubre de 2000 y febrero de 2003 en el laboratorio de artrópodos, Corrientes, Argentina. Se conformaron cinco cohortes de 100 huevos cada una. Los insectos se alimentaron sobre gallina (Gallus domesticus. Las cohortes se controlaron semanalmente. La experiencia se llevó a cabo en condiciones controladas de temperatura (28±3ºC y humedad relativa del aire (63±10%. Se elaboraron tablas completas de vida y se obtuvieron estadísticos vitales. RESULTADOS: La mayor mortalidad se registró en ninfas de primero a cuarto estadio. A partir del quinto estadio el número de individuos decreció en forma constante. La expectativa de vida, después de superar las edades críticas, disminuyó en forma lineal. La supervivencia media de los adultos fue 50,2 semanas. La primera oviposición ocurrió a las 40,6 semanas. La fecundidad fue 859,6 huevos, con una media de 22,8 huevos. El período reproductivo fue de 37,7 semanas. El tiempo generacional fue de 55,3 semanas y la tasa neta de reproducción 133,7. La tasa intrínseca de incremento natural resultó 0,088. En una distribución estable de edades 25,3% correspondería al estado de huevo, 72,3% al estado ninfal y 2,4% al estado adulto. Los adultos contribuyeron con más del 70% al valor reproductivo total. CONCLUSIONES: Triatoma rubrovaria se caracterizó por una supervivencia prolongada como imago, una edad de la primera reproducción tardía y una tasa intrínseca de incremento natural baja.OBJECTIVE: To obtain T. rubrovaria population parameters in order to describe its demographic characteristics. METHODS: The study was carried out in the laboratory of Arthropods, Corrientes, Argentina, from October 2000 to February 2003. Eggs were grouped to form five 100-egg cohorts. Insects were fed on chickens (Gallus domesticus. The cohorts were

Alguns aspectos da biologia de Triatoma pseudomaculata Corrêa & Espínola, 1964, em condições de laboratório (Hemiptera:Reduviidae:Triatominae

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Teresa Cristina M Gonçalves

1997-03-01

Full Text Available Biology of Triatoma pseudomaculata Corrêa & Espínola, 1964, under Laboratory Conditions (Hemiptera:Reduviidae:Triatominae - Observations were made on the evolutive cycle of Triatoma pseudomaculata, held under laboratory conditions, fed weekly on bird (pigeon. Of 60 eggs obtained, only 34 nymphs reached the adult stage in a period of X(S=398±76 days. The following parameters were observed: the time immature stages took to develop from egg to adult emergence; the occurrence of the first meal; the time-lapse between the presenting of the blood-meal and the begining of feeding; time of feeding; amount of blood ingested; variation of weight 24 hr after the blood-meal and until the next blood-meal; and the defecation pattern. The experiment was carried out for 20 months, held in BOD incubator with the average of temperature and humidity of 28±1ºC and 80±5% RU, respectively

Structure of the Triatoma virus capsid

Energy Technology Data Exchange (ETDEWEB)

Squires, Gaëlle; Pous, Joan [Laboratoire de Virologie Moléculaire et Structurale, CNRS, 1 Avenue de la Terrasse, 91198 Gif-sur-Yvette CEDEX (France); Agirre, Jon [Fundación Biofísica Bizkaia, Barrio Sarriena S/N, 48940 Leioa, Bizkaia (FBB) (Spain); Unidad de Biofísica (UBF, CSIC, UPV/EHU), PO Box 644, 48080 Bilbao (Spain); Rozas-Dennis, Gabriela S. [U.N.S., San Juan 670 (8000) Bahía Blanca (Argentina); U.N.S., Avenida Alem 1253 (8000) Bahía Blanca (Argentina); Costabel, Marcelo D. [U.N.S., Avenida Alem 1253 (8000) Bahía Blanca (Argentina); Marti, Gerardo A. [Centro de Estudios Parasitológicos y de Vectores (CEPAVE-CCT, La Plata, CONICET-UNLP), Calle 2 No. 584 (1900) La Plata (Argentina); Navaza, Jorge; Bressanelli, Stéphane [Laboratoire de Virologie Moléculaire et Structurale, CNRS, 1 Avenue de la Terrasse, 91198 Gif-sur-Yvette CEDEX (France); Guérin, Diego M. A., E-mail: diego.guerin@ehu.es [Fundación Biofísica Bizkaia, Barrio Sarriena S/N, 48940 Leioa, Bizkaia (FBB) (Spain); Unidad de Biofísica (UBF, CSIC, UPV/EHU), PO Box 644, 48080 Bilbao (Spain); Rey, Felix A., E-mail: diego.guerin@ehu.es [Laboratoire de Virologie Moléculaire et Structurale, CNRS, 1 Avenue de la Terrasse, 91198 Gif-sur-Yvette CEDEX (France)

2013-06-01

The crystallographic structure of TrV shows specific morphological and functional features that clearly distinguish it from the type species of the Cripavirus genus, CrPV. The members of the Dicistroviridae family are non-enveloped positive-sense single-stranded RNA (+ssRNA) viruses pathogenic to beneficial arthropods as well as insect pests of medical importance. Triatoma virus (TrV), a member of this family, infects several species of triatomine insects (popularly named kissing bugs), which are vectors for human trypanosomiasis, more commonly known as Chagas disease. The potential use of dicistroviruses as biological control agents has drawn considerable attention in the past decade, and several viruses of this family have been identified, with their targets covering honey bees, aphids and field crickets, among others. Here, the crystal structure of the TrV capsid at 2.5 Å resolution is reported, showing that as expected it is very similar to that of Cricket paralysis virus (CrPV). Nevertheless, a number of distinguishing structural features support the introduction of a new genus (Triatovirus; type species TrV) under the Dicistroviridae family. The most striking differences are the absence of icosahedrally ordered VP4 within the infectious particle and the presence of prominent projections that surround the fivefold axis. Furthermore, the structure identifies a second putative autoproteolytic DDF motif in protein VP3, in addition to the conserved one in VP1 which is believed to be responsible for VP0 cleavage during capsid maturation. The potential meaning of these new findings is discussed.

Structure of the Triatoma virus capsid

International Nuclear Information System (INIS)

Squires, Gaëlle; Pous, Joan; Agirre, Jon; Rozas-Dennis, Gabriela S.; Costabel, Marcelo D.; Marti, Gerardo A.; Navaza, Jorge; Bressanelli, Stéphane; Guérin, Diego M. A.; Rey, Felix A.

2013-01-01

The crystallographic structure of TrV shows specific morphological and functional features that clearly distinguish it from the type species of the Cripavirus genus, CrPV. The members of the Dicistroviridae family are non-enveloped positive-sense single-stranded RNA (+ssRNA) viruses pathogenic to beneficial arthropods as well as insect pests of medical importance. Triatoma virus (TrV), a member of this family, infects several species of triatomine insects (popularly named kissing bugs), which are vectors for human trypanosomiasis, more commonly known as Chagas disease. The potential use of dicistroviruses as biological control agents has drawn considerable attention in the past decade, and several viruses of this family have been identified, with their targets covering honey bees, aphids and field crickets, among others. Here, the crystal structure of the TrV capsid at 2.5 Å resolution is reported, showing that as expected it is very similar to that of Cricket paralysis virus (CrPV). Nevertheless, a number of distinguishing structural features support the introduction of a new genus (Triatovirus; type species TrV) under the Dicistroviridae family. The most striking differences are the absence of icosahedrally ordered VP4 within the infectious particle and the presence of prominent projections that surround the fivefold axis. Furthermore, the structure identifies a second putative autoproteolytic DDF motif in protein VP3, in addition to the conserved one in VP1 which is believed to be responsible for VP0 cleavage during capsid maturation. The potential meaning of these new findings is discussed

The peri-urban interface and house infestation with Triatoma infestans in the Argentine Chaco: an underreported process?

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Yael M Provecho

2014-10-01

Full Text Available Peri-urban infestations with triatomine bugs, their sources and their dynamics have rarely been investigated. Here, we corroborated the reported occurrence of Triatoma infestans in a peri-urban area and in neighbouring rural houses in Pampa del Indio, in the Argentine Chaco, and identified its putative sources using spatial analysis and demographic questionnaires. Peri-urban householders reported that 10% of their premises had triatomines, whereas T. infestans was collected by timed manual searches or community-based surveillance in only nine (3% houses. Trypanosoma cruzi-infected T. infestans and Triatoma sordida were collected indoors only in peri-urban houses and were infected with TcV and TcI, respectively. The triatomines fed on chickens, cats and humans. Peri-urban infestations were most frequent in a squatter settlement and particularly within the recently built mud houses of rural immigrants, with large-sized households, more dogs and cats and more crowding. Several of the observed infestations were most likely associated with passive bug transport from other sources and with active bug dispersal from neighbouring foci. Thus, the households in the squatter settlement were at a greater risk of bug invasion and colonisation. In sum, the incipient process of domestic colonisation and transmission, along with persistent rural-to-urban migratory flows and unplanned urbanisation, indicate the need for active vector surveillance and control actions at the peri-urban interface of the Gran Chaco.

First record of Megaselia scalaris (Loew) (Diptera: Phoridae) infesting laboratory colonies of Triatoma brasiliensis Neiva (Hemiptera: Reduviidae)

International Nuclear Information System (INIS)

Costa, Jane; Almeida, Carlos E.; Esperanca, Gleidson M.; Morales, Ninive; Mallet, Jacenir R. dos S.; Goncalves, Teresa C.M.; Prado, Angelo P. do

2007-01-01

Megaselia scalaris (Loew) is a cosmopolitan and synanthropic scuttle fly, eclectic in its feeding habits and acts as detritivore, parasite, facultative parasite, and parasitoid. Here we report for the first time M. scalaris infesting laboratory colonies of Triatoma brasiliensis Neiva, the most important Chagas disease vector in semiarid areas of Brazil. M. scalaris larvae were found feeding inside bugs; pupae were found in the esophagus and intestinal regions of T. brasiliensis through dissection. Other relevant information about this finding is also described in this note, including some preventive measures to avoid laboratory colonies infestations. (author)

First record of Megaselia scalaris (Loew) (Diptera: Phoridae) infesting laboratory colonies of Triatoma brasiliensis Neiva (Hemiptera: Reduviidae)

Energy Technology Data Exchange (ETDEWEB)

Costa, Jane; Almeida, Carlos E.; Esperanca, Gleidson M.; Morales, Ninive [Instituto Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ (Brazil). Dept.de Entomologia. Lab. da Colecao Entomologica; Mallet, Jacenir R. dos S.; Goncalves, Teresa C.M. [Instituto Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ (Brazil). Lab. Transmissores de Leishmanioses. Nucleo de Ultraestrutura; Prado, Angelo P. do [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Inst. de Biologia. Dept. de Parasitologia

2007-11-15

Megaselia scalaris (Loew) is a cosmopolitan and synanthropic scuttle fly, eclectic in its feeding habits and acts as detritivore, parasite, facultative parasite, and parasitoid. Here we report for the first time M. scalaris infesting laboratory colonies of Triatoma brasiliensis Neiva, the most important Chagas disease vector in semiarid areas of Brazil. M. scalaris larvae were found feeding inside bugs; pupae were found in the esophagus and intestinal regions of T. brasiliensis through dissection. Other relevant information about this finding is also described in this note, including some preventive measures to avoid laboratory colonies infestations. (author)

Influence of mating on ovarian follicle development in Triatoma infestans (Klug, 1834

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S. Asin

1992-09-01

Full Text Available This works examines the influence of mating on ovarian follicle development in Triatoma infestans. The observations were carried out on both virgin and mated females, wich were killed at various times after their emergence. There was no difference in the ovarian development of both experimental groups during the first gonadotrofic cycle. By the 7th day mated females as well as virgn females showed vitellogenic oocytes. The coriogenesis and ovulation process began on the 13th day after imaginal moulting. However we could observe that egg-laying was dependent on mating. Mated females laid eggs whereas virgin females did not lay eggs. However ovarian production was significantly greater in the mated females. It is suggested that in T. infestans mating stimulates egg-laying but it does not influence the oogenesis and ovulation process.

Risk Factors Associated with Triatomines and Its Infection with Trypanosoma cruzi in Rural Communities from the Southern Region of the State of Mexico, Mexico

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Medina-Torres, Imelda; Vázquez-Chagoyán, Juan C.; Rodríguez-Vivas, Roger I.; de Oca-Jiménez, Roberto Montes

2010-01-01

Trypanosoma cruzi prevalence in triatomines and risk factors associated to the presence of the insect were studied in 990 rural houses in the southern region of the State of Mexico, Mexico. In each house, triatomines were collected, and information related to house construction material was obtained. T. cruzi infection was diagnosed in all triatomines. A primary screening was performed using 2 × 2 contingency tables of exposure variables. All variables with P ≤ 0.20 were analyzed by logistic regression. Triatomines (N = 125) were collected from 822 houses and analyzed for T. cruzi infection. Triatoma pallidipennis (97.4%) and Triatoma dimidiata (2.6%) were identified in 52.1% of the localities and in 6.1% of the houses. Infection was found in 28.0% of triatomines, from which 28.9% were nymphs. Factors associated with triatomine infestation were flooring construction material (dirt floor: odds ratio [OR], 10.05; 95% confidence interval [CI], 5.31–18.04; P = 0.0001), house rooms (at least three rooms: OR, 2.04; 95% CI, 1.07–3.86; P = 0.028), and ceiling construction material (cardboard lamina tile: OR, 6.84; 95% CI, 1.49–31.31; P = 0.013). This study shows T. cruzi circulation in triatomines in the area of study, and because triatomines are adapted for living and reproducing in the domestic environment, there is a potential risk of Chagas disease transmission to humans. Also, we can conclude that the construction materials and house inhabitants are risk factors of triatomines infestation. PMID:20064995

Monitoring the domiciliary and peridomiciliary invasion process of Triatoma rubrovaria in the State of Rio Grande do Sul, Brazil

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Almeida Carlos Eduardo

2000-01-01

Full Text Available The presence of Triatoma rubrovaria in Brazil has only been confirmed in the States of Paraná and Rio Grande do Sul (RS, where it is found naturally infected with Trypanosoma cruzi. In the wild environment it occurs in rocky habitats and has an eclectic diet, feeding from cockroaches, reptiles and mammals. Data from the Chagas Disease Control Program obtained by the Fundação Nacional de Saúde, between 1975 and 1997, indicate a growing domiciliary and peridomiciliary invasion of T. rubrovaria in RS, where it has become the most frequently Triatominae species captured in this state since the control of Triatoma infestans. In order to monitor this process, we analyzed collection data derived from 22 years of control campaigns against T. infestans. Collection data for triatomines from domestic habitats show an inverse relationship, with high numbers of T. infestans and low numbers of T. rubrovaria during 1976-1987, compared to the following ten years, 1986-1997, when the number of T. infestans dropped drastically and that of T. rubrovaria increased. There are no consistent indications of intradomiciliary colonization by T. rubrovaria, since only low numbers of nymphs have been captured in the intradomiciliary ecotopes. Nevertheless, this species appears to have preadaptive characteristics for anthropic ecotopes, and should be kept under constant epidemiological surveillance.

Post-control surveillance of Triatoma infestans and Triatoma sordida with chemically-baited sticky traps.

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Rojas de Arias, Antonieta; Abad-Franch, Fernando; Acosta, Nidia; López, Elsa; González, Nilsa; Zerba, Eduardo; Tarelli, Guillermo; Masuh, Héctor

2012-01-01

Chagas disease prevention critically depends on keeping houses free of triatomine vectors. Insecticide spraying is very effective, but re-infestation of treated dwellings is commonplace. Early detection-elimination of re-infestation foci is key to long-term control; however, all available vector-detection methods have low sensitivity. Chemically-baited traps are widely used in vector and pest control-surveillance systems; here, we test this approach for Triatoma spp. detection under field conditions in the Gran Chaco. Using a repeated-sampling approach and logistic models that explicitly take detection failures into account, we simultaneously estimate vector occurrence and detection probabilities. We then model detection probabilities (conditioned on vector occurrence) as a function of trapping system to measure the effect of chemical baits. We find a positive effect of baits after three (odds ratio [OR] 5.10; 95% confidence interval [CI(95)] 2.59-10.04) and six months (OR 2.20, CI(95) 1.04-4.65). Detection probabilities are estimated at p ≈ 0.40-0.50 for baited and at just p ≈ 0.15 for control traps. Bait effect is very strong on T. infestans (three-month assessment: OR 12.30, CI(95) 4.44-34.10; p ≈ 0.64), whereas T. sordida is captured with similar frequency in baited and unbaited traps. Chemically-baited traps hold promise for T. infestans surveillance; the sensitivity of the system at detecting small re-infestation foci rises from 12.5% to 63.6% when traps are baited with semiochemicals. Accounting for imperfect detection, infestation is estimated at 26% (CI(95) 16-40) after three and 20% (CI(95) 11-34) after six months. In the same assessments, traps detected infestation in 14% and 8.5% of dwellings, whereas timed manual searches (the standard approach) did so in just 1.4% of dwellings only in the first survey. Since infestation rates are the main indicator used for decision-making in control programs, the approach we present may help improve T

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

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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

Effect of feeding frequency on the reproductive efficiency of two species of Triatoma with different epidemiological importance

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Claudia Rodríguez

2014-07-01

Full Text Available Introduction In Triatominae, reproductive efficiency is an important factor influencing population dynamics, and a useful parameter in measuring a species' epidemiological significance as a vector of Trypanosoma cruzi (Chagas, 1909. The reproductive efficiency of triatomines is affected by food availability; hence, we measured and compared the effects of feeding frequency on the reproductive parameters of Triatoma patagonica (Del Ponte, 1929 and Triatoma infestans (Klug, 1934, and the effects of starvation on T. patagonica. Methods Couples from both species were fed weekly, or every 3 weeks; in addition, females in couples of T. patagonica were not fed. Each couple was observed weekly and reproductive efficiency was assessed on the following parameters: fecundity (eggs/female, fertility (eggs hatched/eggs laid, initiation and end of oviposition, initiation of mating, number of matings/week, and number of reproductive weeks. Relative meal size index (RMS, blood consumption index (CI, and E values (eggs/mg blood were also calculated. Results Changes in feeding frequency affected the reproductive parameters of T. patagonica only, with a decrease in fecundity and number of reproductive weeks for those fed every 3 weeks, or not fed. The reproductive period, RMS index, and CI were lower for T. patagonica than T. infestans. However, despite the lower fecundity of T. patagonica, this species required less blood to produce eggs, with an E values of 2 compared to 2.94 for T. infestans. Conclusions Our results suggest that the differences in fecundity observed between species reflect the availability of food in their natural ecotopes.

Feeding and defaecation behaviour of Triatoma patagonica (Del Ponte, 1929 (Hemiptera: Reduviidae

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Julieta Nattero

2002-10-01

Full Text Available Among the vectors of Chagas disease, Triatoma patagonica is a species in the process of adaptation to the human environment being recently registered in urban and suburban zones. However, its importance as a vector of Chagas disease is unknown. The aim of this work was to evaluate two aspects of vectorial competence: the feeding behaviour and the defaecation pattern. These processes were studied in females of T. patagonica fed ad libitum on a restrained pigeon. The results showed that the blood meal size was negatively correlated with the time of first defaecation (r = -0.42. The first defaecation was emitted before the first 10 min and defaecations during feeding were frequent. A total of 73% of females, defaecated during the first 30 min post-feeding. These results suggest that if this species subsequently colonizes the domicile, it would be capable of transmitting Trypanosoma cruzi.

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.

La aerotermia como alternativa para el control de Triatoma infestans (Hemiptera, Reduviidae resistentes a deltametrina Air temperature elevation as an alternative for the control of deltamethrin-resistant Triatoma infestans (Hemiptera, Reduviidae

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Alberto G. Gentile

2004-08-01

Full Text Available Se exploraron los efectos de la elevación artificial de la temperatura del aire sobre las formas embrionarias, ninfales y adultas de Triatoma infestansresistentes a Deltametrina. En laboratorio, se expuso a temperaturas crecientes del aire la progenie completa de T. infestans, para determinar viabilidad de huevos y supervivencia en ninfas y adultos; sobre el terreno, la experimentación se llevó a cabo en una vivienda tipo rancho previamente evaluada como colonizada. Durante la fase de laboratorio se comprobó la inviabilidad del 100% de los huevos y la mortalidad del 100% de las ninfas y adultos expuestos a temperaturas del aire estanco de entre 45ºC y 55ºC, mientras que en la fase de terreno se logró reproducir el efecto ovicida del calor, como así también la negativización de las evaluaciones entomológicas de la vivienda de experimentación, llevadas a cabo a las 72 horas, a los 30, 60 y 90 días. La elevación artificial de la temperatura del aire estanco en las habitaciones resultó ser un método de control de eficacia aceptable, inocuo y técnicamente sencillo.This study explores the effects of artificial air temperature elevation on the embryonic, nymphal, and adult forms of deltamethrin-resistant Triatoma infestans. In the laboratory, complete offspring of T. infestanswere exposed to increasing air temperatures to determine the viability of eggs and survival of nymphs and adults; in the field, the experiment was conducted in a poor rural dwelling previously identified as infested with the vector. The laboratory phase showed 100% non-viability of eggs and 100% mortality of nymphs and adults exposed to airtight temperatures from 45ºC to 55ºC, while the field phase succeeded in reproducing the heat's ovicidal effect and negative conversion of entomological assays in the experimental dwelling, as conducted over the course of 72 hours at 30, 60, and 90 days from the baseline evaluation. Artificial elevation of airtight temperature

Estudos sobre a resistência ao jejum e aspectos nutricionais de Triatoma lecticularia (Stal, 1859 (Hemiptera, Reduviidae, Triatominae Studies on the resistance to fasting and nutritional aspects of Triatoma lecticularia (Stal, 1859 (Hemiptera, Reduviidae, Triatominae

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José Jurberg

1989-09-01

Full Text Available Foi feito um estudo sobre a resistência ao jejum em todas as fases evolutivas e pesagens em diferentes situações nutricionais de Triatoma lecticularia (alimentado; não alimentado; na morte após o jejum com temperatura e umidade registradas. Observou-se que os períodos de resistência das fases ninfais apresentaram médias (dias crescentes: 1º: 45,84; 2º: 61; 3º: 88,74; 4º: 123,47; 5º 162,30. Na fase adulta as médias foram aproximadas à do 3º estádio (para os machos 88,94 e para as fêmeas 83,66. O procedimento de pesagens permitiu registrar a quantidade de sangue ingerido, a perda de peso durante o jejum e o respectivo percentual em relação ao peso inicial. Esta espécie tem assinalada sua distribuição geográfica na região Neártica, onde tem sido encontrda infectada com Trypanosoma cruzi associada a Neotoma micropus Baird e Spermophilus variagatus (Erxeleben.The resistance to fasting of Triatoma lecticularia was studied in all phases of the life cycle and the insect weighed in different nutritional situations (fed, not fed, death after starvation. The temperature and humidity level were also recorded. The nymphal phases showed increasing resistance to fasting as demonstrated by the following averages (days 1st 45.84; 2nd 61; 3rd 88.74; 4th 123.44; 5th 162.30. Upon the adult phase, the averages were similar to those of the 3rd stage for the male insects 88.94 and for females 83.66. The weighing technique allowed for the measeurement of the quantity of blood ingested, the weight loss during the fast and the percentage weight lost as related to the initial weight. The species is found in the Neartic region where it has been found infected with Trypanosoma cruzi and is associated with the terrestial rodents Neotoma micropus Baird and Spermophilus variagatus (Erxelebem.

Incoordination, Paralysis and Recovery after Pyrethroid Treatment on Nymphs III of Triatoma infestans (Hemiptera: Reduviidae

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Raúl A Alzogaray

1997-05-01

Full Text Available Symptoms of poisoning for deltamethrin and cis-permethrin on nymphs III of Triatoma infestans were described. The time required for incoordination and paralysis were determined. Deltamethrin was equal or more rapid in the onset of the first effect (accordingly to dose, and cis-permethrin in the onset of the second one. There were no significant differences between incoordination doses 50% (IncD50s at different times for the two pyrethroids. They showed equivalent incoordination power, but the nymphs treated with deltamethrin recovered slightly more rapid and in greater amount than the nymphs treated with cis-permethrin. The recovery was inhibited by the simultaneus application of piperonyl butoxide. This result suggests that biotransformation by mixed-function microsomal oxidases are involved in the process of recovery

Molecular Diversity of Trypanosoma cruzi Detected in the Vector Triatoma protracta from California, USA.

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Lisa A Shender

2016-01-01

Full Text Available Trypanosoma cruzi, causative agent of Chagas disease in humans and dogs, is a vector-borne zoonotic protozoan parasite that can cause fatal cardiac disease. While recognized as the most economically important parasitic infection in Latin America, the incidence of Chagas disease in the United States of America (US may be underreported and even increasing. The extensive genetic diversity of T. cruzi in Latin America is well-documented and likely influences disease progression, severity and treatment efficacy; however, little is known regarding T. cruzi strains endemic to the US. It is therefore important to expand our knowledge on US T. cruzi strains, to improve upon the recognition of and response to locally acquired infections.We conducted a study of T. cruzi molecular diversity in California, augmenting sparse genetic data from southern California and for the first time investigating genetic sequences from northern California. The vector Triatoma protracta was collected from southern (Escondido and Los Angeles and northern (Vallecito California regions. Samples were initially screened via sensitive nuclear repetitive DNA and kinetoplast minicircle DNA PCR assays, yielding an overall prevalence of approximately 28% and 55% for southern and northern California regions, respectively. Positive samples were further processed to identify discrete typing units (DTUs, revealing both TcI and TcIV lineages in southern California, but only TcI in northern California. Phylogenetic analyses (targeting COII-ND1, TR and RB19 genes were performed on a subset of positive samples to compare Californian T. cruzi samples to strains from other US regions and Latin America. Results indicated that within the TcI DTU, California sequences were similar to those from the southeastern US, as well as to several isolates from Latin America responsible for causing Chagas disease in humans.Triatoma protracta populations in California are frequently infected with T. cruzi

Triatoma mexicana (Hemiptera: Reduviidae in Guanajuato, Mexico: house infestation and seasonal variation

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Paz María Salazar Schettino

2007-11-01

Full Text Available Triatoma mexicana was described by Herrich-Schaeffer in 1848. In 1940, a male specimen was found in Hidalgo. In 1970, this species was recorded in the state of Queretaro. Later, it was registered in Guanajuato and San Luis Potosi. In the present paper we performed an investigation in 545 dwellings from three counties in the state of Guanajuato, Mexico, from March 2003 to May 2004. The search and capture of triatomines were seasonally performed indoors and outdoors. Entomological indexes were calculated. The risk and no risk relations between triatomine presence and housing construction materials were analyzed. Fourteen triatomines were collected indoors and 151 outdoors. The vectors were collected in houses built with either risky and non-risky materials. Adults go indoors but do not settle there, hence, no relationship was found between the building materials and infestation of houses. Conventional interventions like house improvement or insecticide spraying are not efficient for the control of T. mexicana, because its developmental cycle is accomplished outdoors in the area surrounding the houses.

Residual infestation and recolonization during urban Triatoma infestans Bug Control Campaign, Peru.

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Barbu, Corentin M; Buttenheim, Alison M; Pumahuanca, Maria-Luz Hancco; Calderón, Javier E Quintanilla; Salazar, Renzo; Carrión, Malwina; Rospigliossi, Andy Catacora; Chavez, Fernando S Malaga; Alvarez, Karina Oppe; Cornejo del Carpio, Juan; Náquira, César; Levy, Michael Z

2014-12-01

Chagas disease vector control campaigns are being conducted in Latin America, but little is known about medium-term or long-term effectiveness of these efforts, especially in urban areas. After analyzing entomologic data for 56,491 households during the treatment phase of a Triatoma infestans bug control campaign in Arequipa, Peru, during 2003-2011, we estimated that 97.1% of residual infestations are attributable to untreated households. Multivariate models for the surveillance phase of the campaign obtained during 2009-2012 confirm that nonparticipation in the initial treatment phase is a major risk factor (odds ratio [OR] 21.5, 95% CI 3.35-138). Infestation during surveillance also increased over time (OR 1.55, 95% CI 1.15-2.09 per year). In addition, we observed a negative interaction between nonparticipation and time (OR 0.73, 95% CI 0.53-0.99), suggesting that recolonization by vectors progressively dilutes risk associated with nonparticipation. Although the treatment phase was effective, recolonization in untreated households threatens the long-term success of vector control.

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

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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

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

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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

Dados sôbre a biologia do Triatoma arthurneivai no sudeste do Estado de São Paulo, Brasil (Hemiptera, Reduviidae

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Oswaldo Paulo Forattini

1968-12-01

Full Text Available Assinala-se o encontro de focos naturais do Triatoma arthurneivai Lent e Martins, 1940, na localidade de Itupararanga, Município de Votorantim, no Estado de São Paulo. Os ecótopos apresentaram as mesmas características já assinaladas anteriormente em regiões vizinhas, ou sejam, as de espaços localizados entre lascas de pedras de «granito róseo». O triatomíneo apresentou-se associado com lagartos Tropidurus torquatus Wied. mas, no laboratório, mostrou acentuada avidez por sangue de camundongos albinos. Por outro lado, a infecção experimental com Trypanosoma cruzi (cêpa F-1 foi obtida com facilidade. Em vista dos dados coletados, os autores permitem-se tecer considerações sôbre a possibilidade desse hemíptero vir a desempenhar algum papel transmissor, na natureza.An area with natural foci of Triatoma arthurneivai Lent & Martins, 1940, is recorded at the place of Itupararanga in the county of Salto de Pirapora, São Paulo State, Brasil. These foci were represented by ecotopes placed between sliced stones, similar to the ones previously described in surrounding regions. An association with lizards Tropidurus torquatus Wied. it was suspected to be of feeding nature. Nevertheless the triatomids showed to eat quickly and intensively white mice, under laboratory conditions. Beside this, the experimental infection by Trypanosoma cruzi was easily obtained. These data led the authors to suspect that T. arthurneivai may play some transmission role in nature.

A mass collection of Triatoma ryckmani (Hemiptera:Reduviidaefrom Stenocereus eichlamii (Cactaceaein the semiarid region of Guatemala

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Ricardo Marroquín M

2004-12-01

Full Text Available A population of 216 specimens of Stenocereus eichlamii (Cactaceae,Subfamily Cereoideae was surveyed for Triatoma ryckmani (vector of Chagas diseasein a one hectare plot of semiarid habitat in Guatemala. Out of 44 plants that had dead and dry sections,24 plants had a total of 103 specimens of T.ryckmani .In comparison with other areas of Guatemala,T.ryckmani is well established in the semiarid ecosystem (Infestation index 54.5,density =2.3 and crowding index 4.3.The insects were mainly found (52.4%in the dead portions of S.eichlamii 2.0 to 3.2 m above the ground (X² =26.0,PEn Guatemala,en una hectárea de la región semiárida,se encontraron 216 cactus de Stenocereus eichlamii (Cactaceae,44 de ellos tenían alguna parte del tallo en condiciones secas.103 Triatoma ryckmani fueron halladas en 24 de esos 44 S.eichlamii .Una comparación de los índices entomológicos con otros vectores domiciliares de la enfermedad de Chagas en Guatemala,da la idea que T. ryckmani está bien establecida en el ecosistema semiárido (índice de infestación de 54.5,índice de densidad de 2.3 e índice de hacinamiento de 4.3.Los triatominos fueron hallados preferentemente en las partes muertas de S.eichlamii entre 2.0 a 3.2 m sobre el nivel del suelo (52.4%de triatominos colectados,X ²=26.0,p<0.00001,el siguiente entre 3.2 a 5.0 m (35.9%y finalmente 0.2 a 2.0 m (11.6%. El 75.7 %estaba en condiciones de ayuno y 24.3 %estaban llenas de sangre.Para determinar la presencia de flagelados,43 T.ryckmani fueron disectadas, (primera evaluación de parasitemia en esta especie.Ningún flagelado fue hallado en estos triatominos.Este es el primer reporte de la dinámica poblacional de T.ryckmani en su hábitat silvestre.

Evaluación de la b-cipermetrina para el control de Triatoma infestans Evaluation of beta-cypermethrin for control of Triatoma infestans

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Eduardo Nicolás Zerba

1997-02-01

Full Text Available En este estudio se evaluó en el laboratorio y en el campo el efecto insecticida sobre Triatoma infestans, vector de la enfermedad de Chagas, del nuevo piretroide ß-cipermetrina, y se comparó con el de la deltametrina. La comparación de las dosis letales 50 (DL50 de ambos piretroides indicó que la ß-cipermetrina es más efectiva en ninfas y la deltametrina, en adultos. La evaluación de la concentración letal 50 (CL50 de las dos formulaciones floables de ambos insecticidas depositados sobre distintos soportes mostró que su efectividad en vidrio es similar. En cerámica, la deltametrina es ligeramente más efectiva. Los dos insecticidas floables se evaluaron en 100 viviendas infestadas de la provincia de Santiago del Estero, Argentina. La deltametrina floable se aplicó a una concentración superficial de 25 mg/m² y la ß-cipermetrina, de 50 mg/m². Las concentraciones superficiales reales de ambos productos se analizaron por medio de papeles de filtro colocados en paredes y techos. El análisis por cromatografía de gases mostró buena coincidencia con las concentraciones previstas. Asimismo, se realizaron evaluaciones entomológicas 60, 90, 180 y 365 días después de los tratamientos. Solo en la última evaluación se encontró 10% de infestación en peridomicilios de viviendas tratadas con ß-cipermetrina y 7% en las viviendas tratadas con deltametrina (6% en el peridomicilio y 1% en el domicilio. Los resultados indican que la efectividad de la ß-cipermetrina para controlar a T. infestans cuando se aplica a una concentración de 50 mg/m² es similar a la de la deltametrina cuando esta se administra a una concentración de 25 mg/m².This study assessed the insecticidal effect in the laboratory and in the field of the new pyrethroid ß-cypermethrin against Triatoma infestans, the vector of Chagas' disease, and compared it with that of deltamethrin. Comparison of the 50% lethal dosis (LD50 of both pyrethroids showed that �

Triatoma ryckmani (Hemiptera: Reduviidae) in the epiphyte Tillandsia xerographica (Bromeliaceae) in the semiarid region of Guatemala.

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Marroquín, Ricardo; Monroy, Carlota; Jaenson, Thomas G T

2004-05-01

For the first time, the reduviid bug Triatoma ryckmani Zeledón and Ponce (Hemiptera; Reduviidae) was recorded to inhabit the epiphyte Tillandsia xerographica Rohweder (Bromeliaceae) in the semiarid region of Guatemala. These bromeliads grow mainly in drought-resistant trees with rough bark such as Pereskia lychnidiflora (Cactaceae). In our study site, we investigated 30 T. xerographica, and 53 specimens of T. ryckmani were found. Most T. ryckmani (68.5%) were unfed. Ants (Formicidae) were the predominant (92.2%) insect taxon in T. xerographica. Other insects such as Blattidae (3.0%), Reduviidae (T. ryckmani: 2.5%), Blaberidae (2.2%), Gryllidae (0.1%), and Acrididae (0.1%) were recorded in the bromeliads. T. xerographica is illegally commercialized without previous inspection. This may cause accidental introduction of T. ryckmani to houses and to other countries.

Influência de hábitos antrópicos na dispersão de Triatoma pseudomaculata Corrêa & Espínola, 1964, através de Mimosa tenuiflora (Willdenow (Mimosaceae no Estado do Ceará, Brasil Influence of anthropic habits in the dispersion of Triatoma pseudomaculata Corrêa & Espínola, 1964 through Mimosa tenuiflora (Willdenow (Mimosaceae in the State of Ceará, Brazil

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Simone Patrícia Carneiro Freitas

2004-02-01

Full Text Available Triatoma pseudomaculata foram capturados em entrecascas de Mimosa tenuiflora (jurema-preta em ecótopo silvestre de sete municípios do Estado do Ceará. Esta planta apresenta alta taxa de cobertura geográfica nas áreas de caatingas, sendo freqüentemente utilizada pela população rural. A presença de triatomíneos no peridomicílio, na região do Cariri, pode estar associada ao uso pela população da madeira de M. tenuiflora, quando trazida do ambiente silvestre, repleta de triatomíneos, facilitando conseqüentemente sua mobilização e dispersão.Triatoma pseudomaculata was captured in the phloem of the black acacia bush (Mimosa tenuiflora in seven municipalities in the State of Ceará, Brazil. This bush is widespread in the caatinga (scrub forest and is used extensively by the rural population for kindling. Peridomiciliary presence of triatomines in the Cariri region may be associated with the use of infested M. tenuiflora wood by the population, thus facilitating the triatomines' mobilization and dispersion.

Chagas Disease in Dogs from Endemic Areas of Costa Rica

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Montenegro Victor M

2002-01-01

Full Text Available Dogs with the presumptive diagnosis of Chagas disease are commonly sent to our School of Veterinary Medicine by independent veterinarians. This prompted us to evaluate the prevalence of canine trypanosomiasis in some villages of the Central Valley of Costa Rica. A total of 54 dogs (21 males and 33 females from five rural villages, with ages between 3 months and 10 years old, were bled and submitted to three serological tests: indirect immunofluorescence, indirect hemagglutination and ELISA. Among all animals, 15 (27.7% revealed antibodies (6 pure bred and 9 mongrels and in 3 of them the parasite was also demonstrated by xenodiagnosis. All positive animals except 1, and 9 negative animals (control group were examined by X-rays and electrocardiography, revealing different degrees of cardiomegaly and ECG alteration, consistent with Chagas disease pathology in one dog (SA-11 of the infected ones. Examination of 50 inhabitants living in the houses where dogs and Triatoma dimidiata were found, yielded negative serological reactions. This was assumed to support the hypothesis that dogs are commonly infected by the oral route, a more effective means of infection compared with the vector transmission mechanism that occurs in humans.

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

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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.

Biology of Triatominae (Reduviidae Hemiptera from North of Formosa County (Goiás-Brazil I. Length of life cycle of Triatoma sordida (Stal. 1859

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Dalva A. Mello

1976-12-01

Full Text Available In the present paper the life cycle of Triatoma sordida was studied. The mean length from egg to adult was 213 days. The mean length in days from each stage was: 24.3 (± 1.30 for the first. 32.8 (± 1.45 (2nd, 36.1 (± 1.50 (3rd, 44.6 (± 1.85 (4th and 52.0 (± 1.92 (5th. The mean egg incubation períod was 23.2 (± 1.40. Overall mortality was 18.8% and egg viability was 82.5%.Foi estudado no presente trabalho o ciclo biológico do Triatoma sordida A média da duração do ciclo de ovo a adulto foi 213 dias. A média de duração em dias para cada estágio foi 24,3 (± 1,30 para o primeiro, 32,8 (± 1,45 para o segundo, 36,1 (± 1,50 para o terceiro, 44,6 (± 1,85 para o quarto e 52,0 (± 1,92 para o quinto. A média do período de incubação dos ovos foi 23,2 (± 1,40. A mortalidade em todos ps estágios foi 18,8% e a viabilidade dos ovos foi 82,5%.

Infestación por triatominos en comunidades indígenas de Valledupar, Colombia

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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.

Residual Infestation and Recolonization during Urban Triatoma infestans Bug Control Campaign, Peru1

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Buttenheim, Alison M.; Pumahuanca, Maria-Luz Hancco; Calderón, Javier E. Quintanilla; Salazar, Renzo; Carrión, Malwina; Rospigliossi, Andy Catacora; Chavez, Fernando S. Malaga; Alvarez, Karina Oppe; Cornejo del Carpio, Juan; Náquira, César; Levy, Michael Z.

2014-01-01

Chagas disease vector control campaigns are being conducted in Latin America, but little is known about medium-term or long-term effectiveness of these efforts, especially in urban areas. After analyzing entomologic data for 56,491 households during the treatment phase of a Triatoma infestans bug control campaign in Arequipa, Peru, during 2003–2011, we estimated that 97.1% of residual infestations are attributable to untreated households. Multivariate models for the surveillance phase of the campaign obtained during 2009–2012 confirm that nonparticipation in the initial treatment phase is a major risk factor (odds ratio [OR] 21.5, 95% CI 3.35–138). Infestation during surveillance also increased over time (OR 1.55, 95% CI 1.15–2.09 per year). In addition, we observed a negative interaction between nonparticipation and time (OR 0.73, 95% CI 0.53–0.99), suggesting that recolonization by vectors progressively dilutes risk associated with nonparticipation. Although the treatment phase was effective, recolonization in untreated households threatens the long-term success of vector control. PMID:25423045

Evolutionary and dispersal history of Triatoma infestans, main vector of Chagas disease, by chromosomal markers.

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Panzera, Francisco; Ferreiro, María J; Pita, Sebastián; Calleros, Lucía; Pérez, Ruben; Basmadjián, Yester; Guevara, Yenny; Brenière, Simone Frédérique; Panzera, Yanina

2014-10-01

Chagas disease, one of the most important vector-borne diseases in the Americas, is caused by Trypanosoma cruzi and transmitted to humans by insects of the subfamily Triatominae. An effective control of this disease depends on elimination of vectors through spraying with insecticides. Genetic research can help insect control programs by identifying and characterizing vector populations. In southern Latin America, Triatoma infestans is the main vector and presents two distinct lineages, known as Andean and non-Andean chromosomal groups, that are highly differentiated by the amount of heterochromatin and genome size. Analyses with nuclear and mitochondrial sequences are not conclusive about resolving the origin and spread of T. infestans. The present paper includes the analyses of karyotypes, heterochromatin distribution and chromosomal mapping of the major ribosomal cluster (45S rDNA) to specimens throughout the distribution range of this species, including pyrethroid-resistant populations. A total of 417 specimens from seven different countries were analyzed. We show an unusual wide rDNA variability related to number and chromosomal position of the ribosomal genes, never before reported in species with holocentric chromosomes. Considering the chromosomal groups previously described, the ribosomal patterns are associated with a particular geographic distribution. Our results reveal that the differentiation process between both T. infestans chromosomal groups has involved significant genomic reorganization of essential coding sequences, besides the changes in heterochromatin and genomic size previously reported. The chromosomal markers also allowed us to detect the existence of a hybrid zone occupied by individuals derived from crosses between both chromosomal groups. Our genetic studies support the hypothesis of an Andean origin for T. infestans, and suggest that pyrethroid-resistant populations from the Argentinean-Bolivian border are most likely the result of

Mitochondrial DNA variation of Triatoma infestans populations and its implication on the specific status of T. melanosoma

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Fernando A Monteiro

1999-09-01

Full Text Available DNA sequence comparison of 412 base-pairs fragments of the mitochondrial cytochrome B gene was used to infer the genetic structure of nine geographical Triatoma infestans populations and their phylogenetic relationship with T. melanosoma and T. brasiliensis. T. infestans and T. melanosoma were compared by morphometry, allozyme and cytogenetic analyses, as well as subjected to reciprocal crosses, in order to clarify the taxonomic status of the latter. No differences were found to distinguish the two species and the crosses between them yielded progeny. T. infestans populations presented four haplotypes that could be separated in two clusters: one formed by the samples from Bolivia (Andes and Chaco and the other formed by samples from Argentina and Brazil. Silvatic and domestic T. infestans populations from Bolivia (Andes were genetically identical.

Susceptibility and resistance to deltamethrin of wild and domestic populations of Triatoma infestans (Reduviidae: Triatominae in Bolivia: new discoveries

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Stéphanie Depickère

2012-12-01

Full Text Available Bolivia is a high-endemic country for Chagas disease, for which the principal vector is Triatoma infestans (Triatominae. This is a mainly domestic species that is also found in the wild environment. Recently, an increasing number of studies have shown the importance of Triatominae resistance to insecticides, especially in Bolivia. Data regarding the susceptibility/resistance of wild and domestic populations of T. infestans to deltamethrin are presented. For the first time, domestic populations of the department of Santa Cruz were tested, showing low resistance. Although most of the wild populations were found to be susceptible to deltamethrin, three populations from three departments showed a mortality rate of less than 100%. This result is emphasised here.

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

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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

Aspectos ecológicos da tripanossomíase americana: VII. Permanência e mobilidade do Triatoma sordida em relação aos ecótopos artificiais Ecological aspects of South American Tripanosomiasis: VII. Permanence and mobility of Triatoma sordida with relation to artificial ecotopes

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Oswaldo Paulo Forattini

1975-12-01

Full Text Available Nas colônias desenvolvidas espontaneamente em ecótopos artificiais, representados por galinheiros experimentais, procurou-se observar a permanência e a mobilidade de Triatoma sordida. Para tanto, procedeu-se à marcação individual de adultos e ninfas de 4.° e 5.° estádios, bem como à instalação de abrigos ao redor daqueles biótopos. Os dados obtidos permitiram observar a curta permanência dos primeiros na colônia, não ultrapassando o período de dois meses para a maioria dessas formas. A mobilidade evidenciou-se pela presença de ovos e ninfas de 1.° estádio, nos esconderijos instalados, e as evidências sugeriram ser devidas à passagem dos adultos por esses ecótopos. Concluiu-se que esta espécie é dotada de elevada capacidade de disseminação, em concordância com sua apreciável valência ecológica.Spontaneous colonies of Triatoma sordida developed in experimental fowlhouses were submitted to observations as regards permanence and mobility of this bug. During thirteen months, adults and nymphs of fourth and fifth in stars were tagged for recapture. Resting traps for atracting bugs were placed around the fowlhouses. Adults showed no more than two months of permanence inside these artificial ecotopes. Eggs and first nymphs found in the resting traps suggested activity of adults coming from the fowlhouses. It was evident that this triatomid has a dispersal capacity and an adult tendency towards leaving the colonies as soon as the first egg batches are layed. After this the female will continue the oviposition inside other ecotopes attempting to develop new colonies. This aspect agress with the high characteristic ecological valence of this bug.

Triatoma infestans em área sob vigilância entomológica para doença de Chagas, Estado de São Paulo, Brasil

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Leite Odair F.

2001-01-01

Full Text Available Atendendo a notificação de encontro, por habitantes da Fazenda Paraíso, área rural do Município de Paulínia, Estado de São Paulo, de um exemplar alado de triatomíneo, procedeu-se a uma investigação epidemiológica em que capturaram-se 109 exemplares de Triatoma infestans em focos situados em construções peridomiciliares. As condições locais favoreciam a colonização por triatomíneos: grande número de construções peridomiciliares abandonadas, habitadas por pombos e pardais, fornecedores de farto alimento para os hemípteros. Eliminaram-se os focos por meio de controle mecânico dos ninhos dos pássaros. Borrifaram-se, com inseticida de ação residual, todas as unidades domiciliares da região. Desde que persistam as condições para a instalação de focos de triatomíneos nessa localidade, é obrigatória a implementação de ações de vigilância. Entretanto, os indicadores entomológicos e sorológicos sugerem não ser preocupante a situação atual. Destaca-se aqui a importância da notificação triatomínica para a detecção de focos de triatomíneos, particularmente os de Triatoma infestans.

Hábito alimentar de Triatoma vitticeps no Estado do Rio de Janeiro, Brasil Feeding patterns of Triatoma vitticeps in the State of Rio de Janeiro, Brazil

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Teresa Cristina M Gonçalves

2000-08-01

Full Text Available OBJETIVO: O estudo do hábito alimentar dos triatomíneos tem contribuído para o conhecimento da sua biologia no habitat natural. Triatoma vitticeps, espécie que vem invadindo freqüentemente o domicílio apresentando-se infectado por T. cruzi, foi analisado sob esse aspecto, possibilitando conhecer a situação epidemiológica da área. MÉTODOS: De fevereiro de 1989 a abril de 1993, 122 espécimes de T. vitticeps foram capturados em duas áreas da localidade de Triunfo, 2° Distrito do Município de Santa Maria Madalena (RJ. Os insetos foram dissecados para a retirada do conteúdo estomacal. Os anti-soros utilizados foram: homem, vaca, cavalo, cão, porco, tatu, gambá, roedor e ave. RESULTADOS: Do total analisado, 79 estavam positivos e 43 negativos para os anti-soros testados: tatu (30,3% > homem e porco (13,1% > ave e cão (11,5% > cavalo (5,7% > gambá (4,9% > roedor (4,1% > boi (3,3%. As fontes alimentares identificadas variaram de 1 a 4 e 6: 0 - 25,41%; 1 - 45,08%; 2 - 10,66%; 3 - 6,56%; 4 - 1,64% e 6 - 0,82%. Quanto à infecção por T. cruzi, 74 espécimes (65,54% estavam positivos, 39 (34,51% negativos e 9 não foram examinados. CONCLUSÕES: Os resultados caracterizam o hábito silvestre de T. vitticeps e a tripanosomíase como uma enzootia. A vigilância epidemiológica se faz necessária para o acompanhamento do comportamento dessa espécie.OBJECTIVE: Feeding patterns of triatomines have contributed to elucidate its biology. Triatoma vitticeps, naturally infected with T. cruzi, has been found in domiciles. Its behavior and epidemiological patterns were investigated. METHODS: One-hundred and twenty two specimens of T. vitticeps were captured from February 1989 to April 1993 in two areas of Triunfo municipality, a subdistrict of Santa Maria Madalena municipal district, State of Rio de Janeiro, Brazil. The insects were dissected and their intestinal contents were removed and tested. It was used antisera from: man, cow, horse, dog

Ecotope effect in Triatoma brasiliensis (Hemiptera: Reduviidae) suggests phenotypic plasticity rather than adaptation.

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Batista, V S P; Fernandes, F A; Cordeiro-Estrela, P; Sarquis, O; Lima, M M

2013-09-01

Triatoma brasiliensis (Hemiptera: Reduviidae) is an important vector of Chagas' disease in both sylvatic and peridomestic ecotopes. Discriminating between these populations of Triatominae has been proposed as a means of investigating re-infestation rates of human dwellings. Geometric morphometrics have been widely applied in the study of Triatominae polymorphisms at species and population levels. This study characterizes morphometric differences between sylvatic and peridomestic populations, as well as between sexes in T. brasiliensis specimens from Jaguaruana, Ceará, in northeastern Brazil. No differences in either the shape or size of the cephalic capsule were apparent between sexes or ecotopes. However, the wings showed differentiation in shape and size. Sexual dimorphism was detected, with females presenting significantly higher values and conformations. Size differentiation was also evident, with sylvatic specimens being generally larger than peridomestic examples. These results indicate that differences in the wings of T. brasiliensis may be related to the existence of phenotypic plasticity, and variations in size and shape may be associated with different ecotopes, possibly as a result of conditions in each micro-habitat, such as temperature, relative humidity, food supply and density. © 2012 The Royal Entomological Society.

Selection of Beauveria bassiana and Metarhizium anisopliae Isolates to Control Triatoma infestans

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Luz Christian

1998-01-01

Full Text Available Twenty three isolates of Beauveria bassiana and 13 isolates of Metarhizium anisopliae were tested on third instar nymphs of Triatoma infestans, a serious vector of Chagas disease. Pathogenicity tests at saturated humidity showed that this insect is very susceptible to fungal infection. At lower relative humidity (50%, conditions expected in the vector microhabitat, virulence was significantly different among isolates. Cumulative mortality 15 days after treatment varied from 17.5 to 97.5%, and estimates of 50% survival time varied from 6 to 11 days. Maintaining lower relative humidity, four B. bassiana and two M. anisopliae isolates were selected for analysis of virulence at different conidial concentrations and temperatures. Lethal concentrations sufficient to kill 50% of insects (LC50 varied from 7.1x105 to 4.3x106 conidia/ml, for a B. bassiana isolate (CG 14 and a M. anisopliae isolate (CG 491 respectively. Most isolates, particularly B. bassiana isolates CG 24 and CG 306, proved to be more virulent at 25 and 30°C, compared to 15 and 20°C. The differential virulence at 50% humidity observed among some B. bassiana isolates was not correlated to phenetic groups in cluster analysis of RAPD markers. In fact, the B. bassiana isolates analyzed presented a high homogeneity (> 73% similarity.

Determinants of the domiciliary density of Triatoma infestans, vector of Chagas disease.

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Gürtler, R E; Cecere, M C; Rubel, D N; Schweigmann, N J

1992-01-01

In two heavily infested rural villages of Santiago del Estero, Argentina, where no indoor-spraying with residual insecticides had ever been carried out by official control services, we studied the influence of roof and wall structure, domestic use of insecticide, family size and the number of domestic dogs, on the domiciliary density of Triatoma infestans (Klug). Bug density was significantly associated with (1) the interaction between insecticide use and type of roof, (2) the structure of indoor walls, (3) the number of dogs sharing sleeping areas of people (room-mate dogs), and (4) the number of people plus room-mate dogs, but not with just the number of people resident in the house. The interaction between insecticide use and a roof made of 'simbol', a locally available grass (Pennisetum sp.), also reflected a younger age structure of domestic bug populations. In infested houses, the density of bugs infected with Trypanosoma cruzi Chagas was significantly correlated with overall bug density. Our data suggest that the application of environmental management measures by the affected people, such as plastering of walls and modification of roofs, coupled with keeping dogs away from bedrooms and application of insecticides, should limit the domestic population density of T. infestans and thus reduce the transmission of T. cruzi to people.

Descrição de ovos e ninfas de Triatoma klugi (Hemiptera, Reduviidae, Triatominae Description of eggs and nymphs of Triatoma klugi (Hemiptera, Reduviidae, Triatominae

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José Jurberg

Full Text Available Os autores descreveram as características morfológicas de Triatoma klugi Carcavallo, Jurberg, Lent & Galvão, 2001 pertencente ao grupo de espécies que compõem o "complexo T. oliveirai". Até o presente tem sido difícil separar essas espécies com base nas características ninfais, o que justifica o desenvolvimento deste trabalho. Os espécimes foram coletados em frestas de rochas no morro Malavok na localidade de Linha Brasil, município de Nova Petrópolis, no Estado do Rio Grande do Sul. O local de captura dos triatomíneos situa-se entre 700 e 800 m de altitude (29º18'38''S, 51º04'57''W. Juntamente com T. oliveirai (Neiva, Pinto & Lent, 1939, espécie morfologicamente mais próxima, são as únicas do complexo que não foram encontradas, até o momento, no Estado do Mato Grosso, Mato Grosso do Sul e Goiás, Brasil. Em condições experimentais, já foi testada e comprovada a sua susceptibilidade à infecção pelo Trypanosoma cruzi (Chagas, 1909 e Trypanosoma rangeli (Tejera, 1920. A análise comparativa das ornamentações do exocório dos ovos e de três estádios ninfais de T. klugi por microscopia óptica e microscopia eletrônica de varredura mostrou algumas particularidades morfológicas, com destaque para: a face ventral da cabeça, o sulco estridulatório e os últimos segmentos abdominais (IX, X - futura genitália e XI - tubo anal. Esses dados contribuem para a ampliação dos parâmetros diferenciais visando à diagnose de T. klugi durante o seu desenvolvimento ninfal.The authors had described the morphologic characteristics of Triatoma klugi Carcavallo, Jurberg, Lent & Galvão, 2001 to the group of species belonging to "T. oliveirai complex". Until the moment it has been difficult to separate on the nymphs characteristics basis these species, what it justifies the development of this work. The specimens had been collected in openings of rocks in the Malavok mount in the locality of Linha Brazil, city of Nova Petr

Could the bug Triatoma sherlocki be vectoring Chagas disease in small mining communities in Bahia, Brazil?

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Almeida, C E; Folly-Ramos, E; Peterson, A T; Lima-Neiva, V; Gumiel, M; Duarte, R; Lima, M M; Locks, M; Beltrão, M; Costa, J

2009-12-01

Searches for Chagas disease vectors were performed at the type locality from which Triatoma sherlocki Papa et al. (Hemiptera: Reduviidae: Triatominae) was described in the municipality of Gentio do Ouro, in the state of Bahia, Brazil, and in a small artisan quarry-mining community approximately 13 km distant in a remote area of the same municipality. The latter site represents a new locality record for this species. Adults, nymphs and exuviae of T. sherlocki were found in 21% of human dwellings, indicating that the species is in the process of domiciliation. Prevalence of Trypanosoma cruzi infection in collected bugs was 10.8%. Simple predictive approaches based on environmental similarity were used to identify additional sites likely suitable for this species. The approach successfully predicted an additional five sites for the species in surrounding landscapes. Ecological and entomological indicators were combined to discuss whether this scenario likely represents an isolated case or an emerging public health problem.

Susceptibilidad y resistencia de Triatoma infestans y Panstrongylus herreri a los insecticidas piretroides, Perú 2001

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Carmen Yon F

2004-07-01

Full Text Available Se evaluaron los niveles de susceptibilidad de triatominos a piretroides con la técnica de la OMS, usando papeles impregnados al 0,1% de ingrediente activo de los siguientes insecticidas: alfacipermetrina, betaciflutrina, ciflutrina, cipermetrina y deltametrina, se emplearon lotes de triatominos de los estadios ninfa V y adultos de Triatoma infestans y Panstrongylus herreri. Se registraron los porcentajes de mortalidad después de las 24 horas de exposición a papeles impregnados con insecticidas, observando que la mayor parte de la población de triatominos de ambas especies era sensibles a los insecticidas. Sólo en algunos casos, se hallaron los niveles de resistencia en los estadios de ninfa V en la especie P. herreri en 2 localidades de la provincia de Jaén, departamento de Cajamarca, asimismo en adultos y ninfas V de T. infestans en especímenes capturados en el valle de Vítor, departamento de Arequipa.

Peridomiciliary colonies of Triatoma vitticeps (Stal, 1859) (Hemiptera, Reduviidae, Triatominae) infected with Trypanosoma cruzi in rural areas of the state of Espírito Santo, Brazil

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Santos, Claudiney Biral dos; Ferreira, Adelson Luiz; Leite, Gustavo Rocha; Ferreira, Gabriel Eduardo Melim; Rodrigues, Andressa Alencastre Fuzari; Falqueto, Aloísio

2005-01-01

In Brazil, the colonization of human dwellings by triatomines occurs in areas with native vegetation of the caatinga or cerrado types. In areas of Atlantic forest such as in the Brazilian state of Espírito Santo, there are no species adapted to live in human habitations. The few autochthonous cases of Chagas disease encountered in Espírito Santo have been attributed to adult specimens of Triatoma vitticeps that invade houses from forest remnants. In recent years, the entomology unit of the Es...

First Report of Widespread Wild Populations of Triatoma infestans (Reduviidae, Triatominae) in the Valleys of La Paz, Bolivia

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Buitrago, Rosio; Waleckx, Etienne; Bosseno, Marie-France; Zoveda, Faustine; Vidaurre, Pablo; Salas, Renata; Mamani, Elio; Noireau, François; Brenière, Simone Frédérique

2010-01-01

Wild populations of Triatoma infestans, the main vector of Chagas disease in the Southern Cone countries, may be involved in reinfestation of human dwellings, limiting the success of vector-control campaigns in Bolivia. Knowledge of the distribution of these populations remains incomplete. We report here the detection of T. infestans wild populations in large areas in the department of La Paz, Bolivia. Among 18 sylvatic areas investigated, 17 were positive with T. infestans specimens. The infection rate of captured T. infestans with Trypanosoma cruzi was 85.7% in adult specimens. These results expand the geographical distribution of wild populations of T. infestans; it may be distributed throughout the Inter-Andean Dry Forest eco-region of Bolivia. The current information allows us to propose the hypothesis that a sylvatic origin of the reinfestation is located in the valleys of La Paz. PMID:20348501

Resistance to Starvation of Triatoma rubrofasciata (De Geer, 1773 under Laboratory Conditions (Hemiptera: Reduviidae: Triatominae

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Rojas Cortéz Mirko G

1998-01-01

Full Text Available The present work aims at learning the period of resistance to starvation (molting/death of Triatoma rubrofasciata in different stages of development and the respective loss of weight until death. Eggs of specimens from the greater area of the city of São Luis in the State of Maranhão, Brazil, yielded approximately 300 nymphs. These nymphs were placed in labelled Borrel glasses, in which they were weekly fed on rats (Rattus norvegicus, until reaching the stage to be observed. The experiments were conducted in a climatic chamber regulated at 29 ± 1° C, 70% relative humidity and 12 hr photoperiod. The resistance to starvation increased according to the stage of development, except for adult bugs, whose results were similar to the 3rd stage nymphs. In all these development stages there was an abrupt loss of weight in the first week, followed by a gradual loss until death. Comparing this work with those of other authors, it was observed that T. rubrofasciata is among the less resistant triatomine species.

Triatoma infestans em área sob vigilância entomológica para doença de Chagas, Estado de São Paulo, Brasil

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Leite,Odair F.; Alves,Maria José C.P.; Souza,Savina S.L.; Mayo,Renata C.; Andrade,Valmir R.; Souza,Celso E.; Rangel,Osias; Oliveira,Susely S.; Lima,Virgilia L.C.; Rodrigues,Vera L.C.C.; Carvalho,Maria Esther de; Casanova,Claudio; Wanderley,Dalva M.V.

2001-01-01

Atendendo a notificação de encontro, por habitantes da Fazenda Paraíso, área rural do Município de Paulínia, Estado de São Paulo, de um exemplar alado de triatomíneo, procedeu-se a uma investigação epidemiológica em que capturaram-se 109 exemplares de Triatoma infestans em focos situados em construções peridomiciliares. As condições locais favoreciam a colonização por triatomíneos: grande número de construções peridomiciliares abandonadas, habitadas por pombos e pardais, fornecedores de farto...

Molecular phylogeography of the Chagas' disease vector Triatoma infestans in Argentina

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Pérez de Rosas, A R; Segura, E L; García, B A

2011-01-01

Triatoma infestans is the main vector of Chagas' disease in South America between latitudes 10°S and 46°S. A multilocus microsatellite data set of 836 individuals from 27 populations of T. infestans, from all its range of distribution in Argentina, was analyzed. Our results favor the hypothesis of two independent migration events of colonization in Argentina and secondary contacts. The majority of the populations of the western provinces of Catamarca, La Rioja, San Juan and the west of Cordoba province, had almost no shared ancestry with the rest of the populations analyzed. Probably those populations, belonging to localities close to the Andean region, could have been established by the dispersal line of T. infestans that would have arrived to Argentina through the Andes, whereas most of the rest of the populations analyzed may have derived from the dispersal line of T. infestans in non-Andean lowlands. Among them, those from the provinces of Formosa, Chaco, Santiago del Estero and Santa Fe shared different percentages of ancestry and presented lower degree of genetic differentiation. The migratory movement linked to regional economies and possibly associated with passive dispersal, would allow a higher genetic exchange among these populations of T. infestans. This study, using microsatellite markers, provides a new approach for evaluating the validity of the different hypotheses concerning the evolutionary history of this species. Two major lineages of T. infestans, an Andean and non-Andean, are suggested. PMID:21224874

Molecular phylogeography of the Chagas' disease vector Triatoma infestans in Argentina.

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Pérez de Rosas, A R; Segura, E L; García, B A

2011-07-01

Triatoma infestans is the main vector of Chagas' disease in South America between latitudes 10°S and 46°S. A multilocus microsatellite data set of 836 individuals from 27 populations of T. infestans, from all its range of distribution in Argentina, was analyzed. Our results favor the hypothesis of two independent migration events of colonization in Argentina and secondary contacts. The majority of the populations of the western provinces of Catamarca, La Rioja, San Juan and the west of Cordoba province, had almost no shared ancestry with the rest of the populations analyzed. Probably those populations, belonging to localities close to the Andean region, could have been established by the dispersal line of T. infestans that would have arrived to Argentina through the Andes, whereas most of the rest of the populations analyzed may have derived from the dispersal line of T. infestans in non-Andean lowlands. Among them, those from the provinces of Formosa, Chaco, Santiago del Estero and Santa Fe shared different percentages of ancestry and presented lower degree of genetic differentiation. The migratory movement linked to regional economies and possibly associated with passive dispersal, would allow a higher genetic exchange among these populations of T. infestans. This study, using microsatellite markers, provides a new approach for evaluating the validity of the different hypotheses concerning the evolutionary history of this species. Two major lineages of T. infestans, an Andean and non-Andean, are suggested.

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.

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.

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.

Assessing the mitochondrial DNA diversity of the Chagas disease vector Triatoma sordida (Hemiptera: Reduviidae

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Grasielle Caldas D‘Ávila Pessoa

2016-01-01

Full Text Available Triatoma sordida is a species that transmits Trypanosoma cruzi to humans. In Brazil, T. sordida currently deserves special attention because of its wide distribution, tendency to invade domestic environments and vectorial competence. For the planning and execution of control protocols to be effective against Triatominae, they must consider its population structure. In this context, this study aimed to characterise the genetic variability of T. sordida populations collected in areas with persistent infestations from Minas Gerais, Brazil. Levels of genetic variation and population structure were determined in peridomestic T. sordida by sequencing a polymorphic region of the mitochondrial cytochrome b gene. Low nucleotide and haplotype diversity were observed for all 14 sampled areas; π values ranged from 0.002-0.006. Most obtained haplotypes occurred at low frequencies, and some were exclusive to only one of the studied populations. Interpopulation genetic diversity analysis revealed strong genetic structuring. Furthermore, the genetic variability of Brazilian populations is small compared to that of Argentinean and Bolivian specimens. The possible factors related to the reduced genetic variability and strong genetic structuring obtained for studied populations are discussed in this paper.

Diatomaceous earth and oil enhance effectiveness of Metarhizium anisopliae against Triatoma infestans.

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Luz, Christian; Rodrigues, Juscelino; Rocha, Luiz F N

2012-04-01

Entomopathogenic fungi, especially Metarhizium anisopliae, have potential for integrated control of peridomestic triatomine bugs. However, the high susceptibility of these vectors to fungal infection at elevated ambient humidities decreases in the comparatively dry conditions that often prevail in their microhabitats. A formulation adapted to this target pest that induces high and quick mortality can help to overcome these drawbacks. In the present study diatomaceous earth, which is used against pests of stored grains or as an additive to mycoinsecticides, delayed but did not reduce in vitro germination of M. anisopliae s.l. IP 46 conidia after >24h agitation without affecting viability, and did not hamper the survival of Triatoma infestans nymphs exposed to treated surfaces. The settling behavior of nymphs on a treated surface in choice tests depended on the concentration of diatomaceous earth and ambient light level. Conidia formulated with diatomaceous earth and a vegetable oil synergized the insecticidal effect of the fungus in nymphs, and quickly killed all treated insects, even at 75% relative humidity (LT(90) 8.3 days) where unformulated conidia caused only 25% mortality after a 25 days exposure. The improved performance of a combined oil and desiccant dust formulation of this Metarhizium isolate raises the likelihood for its successful mycoinsecticidal use for triatomine control and, apparently, against other domestic insect pests. Copyright © 2011 Elsevier B.V. All rights reserved.

Interaction between Didelphis albiventris and Triatoma infestans in relation to Trypanosoma cruzi transmission

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Nicolás J. Schweigmann

1995-12-01

Full Text Available This paper attempts to prove if a high Trypanosoma cruzi prevalence of opossums might be reached with few potential infective contacts. One non-infected Didelphis albiventris to T. cruzi and 10 infected nymphs of Triatoma infestans were left together during 23 hr in a device that simulated a natural opossum burrow. Twenty-six replicates were perfomed using marsupials and triatomines only once. Potentially infective contacts occurred in all the trials. From the 26 opossums used in trials, 54% did not eat any bug. Of the 260 bugs used, 21% were predated. In the 25 trials involving 205 surving bugs, 36 % of them did not feed. In 15/25 cases, maior ou igual a 60% of the triatomines were able to feed. The parasitological follow-up of 24 opossums showed that among 10 that had eaten bugs, 4 turned out infected and among the 14 that had not predate, 3 (21% became positive. In sum, 7/24 (29% of the marsupials acquired the infection after the experiment. This infection rate was similar to the prevalences found for the opossum population of Santiago del Estero, Argentina, suggesting that the prevalences observed in the field might be reached if each marsupial would encounter infected bugs just once in its lifetime.

Deltamethrin Binding to Triatoma infestans (Hemiptera: Reduviidae) Lipoproteins. Analysis by Solvent Bar Microextraction Coupled to Gas Chromatography.

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Dulbecco, A B; Mijailovsky, S J; Girotti, J R; Juárez, M P

2015-11-01

The binding of deltamethrin (DLM) to the hemipteran Triatoma infestans (Klug) hemolymph lipoproteins was evaluated in vitro. After DLM incubation with the insect hemolymph, lipoproteins were fractioned by ultracentrifugation. DLM binding was analyzed by a microextractive technique-solvent bar microextraction-a solventless methodology to extract DLM from each lipoprotein fraction. This is a novel use of the technique applied to extract an insecticide from an insect fluid. Capillary gas chromatography with microelectron capture detection was used to detect DLM bound by the T. infestans hemolymph lipoproteins and to identify the preferred DLM carrier. We show that Lp and VHDLp I lipoproteins are mainly responsible for DLM transport in T. infestans, both in DLM-resistant and DLM-susceptible bugs. Our results also indicate that DLM amounts transported are not related to DLM susceptibility. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Eye colour as a genetic marker for fertility and fecundity of Triatoma infestans (Klug, 1834 Hemiptera, Reduviidae, Triatominae

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Pires Herton Helder Rocha

2002-01-01

Full Text Available Eye colour of Triatoma infestans is controlled at a single autosomal locus, with black-eye as the dominant gene and red-eye as the recessive. Inheritance of these characters follows a classical Mendelian system, enabling eye colour to be used as a marker for studies of mating frequency. We found no significant differences in oviposition rates and egg hatching rates irrespective of parental phenotypes. Different mating schedules between red-eye and black-eye parents showed that eye colour did not affect mating competence. Females mated with a single male or with different males together or in succession produced similar numbers of fertile eggs, with the eye colour of the offspring reflecting exposure to the different males. We conclude that although a single mating can provide sufficient sperm for the whole reproductive life of the female, multiple matings can result in balanced assortative sperm usage from the spermatheca.

Life cycle and reproductive patterns of Triatoma rubrofasciata (De Geer, 1773) (Hemiptera: Reduviidae), under laboratory conditions.

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Braga, M V; Pinto, Z T; Lima, M M

1998-01-01

The life cycle and reproductive patterns of Triatoma rubrofasciata were studied along with laboratory conditions for the establishment of a prolific colony. The insects were divided into four groups: two of them were maintained at room temperature (20.5 degrees C to 33 degrees C and 85% +/- 5% of relative humidity), the other two in a climatic chamber (CC) (temperature: 29 degrees C, humidity: 80% +/- 5%). The groups were fed weekly or fortnightly on Swiss mice. The females from the group kept in the CC and fed weekly had longer life span, as well as a higher number of eggs, fertile eggs and hatchings; the group kept in the CC and fed fortnightly had a shorter life span for the 1st, 2nd and 3rd instars and a lower mortality rate for all instars. It was concluded that a constant high temperature (CC at 29 degrees C) is the most suitable condition for the maintenance of a colony of T. rubrofasciata regardless of the interval between repasts.

Factors affecting infestation by Triatoma infestans in a rural area of the humid Chaco in Argentina: a multi-model inference approach.

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Gurevitz, Juan M; Ceballos, Leonardo A; Gaspe, María Sol; Alvarado-Otegui, Julián A; Enríquez, Gustavo F; Kitron, Uriel; Gürtler, Ricardo E

2011-10-01

Transmission of Trypanosoma cruzi by Triatoma infestans remains a major public health problem in the Gran Chaco ecoregion, where understanding of the determinants of house infestation is limited. We conducted a cross-sectional study to model factors affecting bug presence and abundance at sites within house compounds in a well-defined rural area in the humid Argentine Chaco. Triatoma infestans bugs were found in 45.9% of 327 inhabited house compounds but only in 7.4% of the 2,584 sites inspected systematically on these compounds, even though the last insecticide spraying campaign was conducted 12 years before. Infested sites were significantly aggregated at distances of 0.8-2.5 km. The most frequently infested ecotopes were domiciles, kitchens, storerooms, chicken coops and nests; corrals were rarely infested. Domiciles with mud walls and roofs of thatch or corrugated tarred cardboard were more often infested (32.2%) than domiciles with brick-and-cement walls and corrugated metal-sheet roofs (15.1%). A multi-model inference approach using Akaike's information criterion was applied to assess the relative importance of each variable by running all possible (17,406) models resulting from all combinations of variables. Availability of refuges for bugs, construction with tarred cardboard, and host abundance (humans, dogs, cats, and poultry) per site were positively associated with infestation and abundance, whereas reported insecticide use showed a negative association. Ethnic background (Creole or Toba) adjusted for other factors showed little or no association. Promotion and effective implementation of housing improvement (including key peridomestic structures) combined with appropriate insecticide use and host management practices are needed to eliminate infestations. Fewer refuges are likely to result in fewer residual foci after insecticide spraying, and will facilitate community-based vector surveillance. A more integrated perspective that considers simultaneously

Factors Affecting Infestation by Triatoma infestans in a Rural Area of the Humid Chaco in Argentina: A Multi-Model Inference Approach

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Gurevitz, Juan M.; Ceballos, Leonardo A.; Gaspe, María Sol; Alvarado-Otegui, Julián A.; Enríquez, Gustavo F.; Kitron, Uriel; Gürtler, Ricardo E.

2011-01-01

Background Transmission of Trypanosoma cruzi by Triatoma infestans remains a major public health problem in the Gran Chaco ecoregion, where understanding of the determinants of house infestation is limited. We conducted a cross-sectional study to model factors affecting bug presence and abundance at sites within house compounds in a well-defined rural area in the humid Argentine Chaco. Methodology/Principal Findings Triatoma infestans bugs were found in 45.9% of 327 inhabited house compounds but only in 7.4% of the 2,584 sites inspected systematically on these compounds, even though the last insecticide spraying campaign was conducted 12 years before. Infested sites were significantly aggregated at distances of 0.8–2.5 km. The most frequently infested ecotopes were domiciles, kitchens, storerooms, chicken coops and nests; corrals were rarely infested. Domiciles with mud walls and roofs of thatch or corrugated tarred cardboard were more often infested (32.2%) than domiciles with brick-and-cement walls and corrugated metal-sheet roofs (15.1%). A multi-model inference approach using Akaike's information criterion was applied to assess the relative importance of each variable by running all possible (17,406) models resulting from all combinations of variables. Availability of refuges for bugs, construction with tarred cardboard, and host abundance (humans, dogs, cats, and poultry) per site were positively associated with infestation and abundance, whereas reported insecticide use showed a negative association. Ethnic background (Creole or Toba) adjusted for other factors showed little or no association. Conclusions/Significance Promotion and effective implementation of housing improvement (including key peridomestic structures) combined with appropriate insecticide use and host management practices are needed to eliminate infestations. Fewer refuges are likely to result in fewer residual foci after insecticide spraying, and will facilitate community-based vector

Relação entre Triatoma infestans, aves domésticas e o homem num povoado de Santiago del Estero, Argentina

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Gajate Patrícia P.

1994-01-01

Full Text Available Determinou-se a associação entre Triatoma infestans, aves domésticas e o homem no povoado de Trinidad, Santiago del Estero, Argentina. Para coletar triatomíneos foram realizadas quatro amostragens no peridomicílio de seis casas, utilizando-se o método de captura hora/homem (dezembro de 1991 a outubro de 1992. Os anexos foram classificados em antrópicos (onde o homem realiza atividades cotidianas e não-antrópicos. Além disso, determinou-se o perfil alimentar dos barbeiros. De um total de 134 ecótopos investigados, 21% tinham T. infestans; 22% possuíam aves domésticas; e 54% eram antrópicos. Em 25% destes ecótopos foram encontradas aves e T. infestans simultaneamente. As aves foram os únicos animais domésticos associados com o T. infestans, sendo que esta relação só ocorreu nos ecótopos antrópicos. A proporção de ingestas em aves (61/146 foi altamente significativa. Em Trinidad não há galinheiros, utilizando-se, assim, os anexos entrópicos do peridomicílio como local para se construir os ninhos para as aves. tanto pelos elementos usados na preparação dos ninhos como pelo uso posterior dos mesmos, poder-se-ia estabelecer um fluxo periódico de barbeiros do intradomicílio para o peridomicílio, e vice-versa, através do transporte passivo. Esta relação estreita entre Triatoma infestans, aves domésticas e o homem, encontrada nos ecótopos antrópicos, onde também existem outros reservatórios de T. cruzi, como os cães, favorece a manutenção de colônias de barbeiros domiciliares e a transmissão da doença de Chagas ao homem.

Relação entre Triatoma infestans, aves domésticas e o homem num povoado de Santiago del Estero, Argentina

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Patrícia P. Gajate

Full Text Available Determinou-se a associação entre Triatoma infestans, aves domésticas e o homem no povoado de Trinidad, Santiago del Estero, Argentina. Para coletar triatomíneos foram realizadas quatro amostragens no peridomicílio de seis casas, utilizando-se o método de captura hora/homem (dezembro de 1991 a outubro de 1992. Os anexos foram classificados em antrópicos (onde o homem realiza atividades cotidianas e não-antrópicos. Além disso, determinou-se o perfil alimentar dos barbeiros. De um total de 134 ecótopos investigados, 21% tinham T. infestans; 22% possuíam aves domésticas; e 54% eram antrópicos. Em 25% destes ecótopos foram encontradas aves e T. infestans simultaneamente. As aves foram os únicos animais domésticos associados com o T. infestans, sendo que esta relação só ocorreu nos ecótopos antrópicos. A proporção de ingestas em aves (61/146 foi altamente significativa. Em Trinidad não há galinheiros, utilizando-se, assim, os anexos entrópicos do peridomicílio como local para se construir os ninhos para as aves. tanto pelos elementos usados na preparação dos ninhos como pelo uso posterior dos mesmos, poder-se-ia estabelecer um fluxo periódico de barbeiros do intradomicílio para o peridomicílio, e vice-versa, através do transporte passivo. Esta relação estreita entre Triatoma infestans, aves domésticas e o homem, encontrada nos ecótopos antrópicos, onde também existem outros reservatórios de T. cruzi, como os cães, favorece a manutenção de colônias de barbeiros domiciliares e a transmissão da doença de Chagas ao homem.

[Triatoma vandae sp.n. of the oliveirai complex from the State of Mato Grosso, Brazil (Hemiptera: Reduviidae: Triatominae)].

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Carcavallo, Rodolfo U; Jurberg, José; Rocha, Dayse da Silva; Galvao, Cleber; Noireau, François; Lent, Herman

2002-07-01

There are several specific complexes belonging to the genus Triatoma Laporte, 1832, which are generally associated to specific geographic areas. Recent publications have linked the oliveirai complex to ecosystems of Mato Grosso, which are also present in other Brazilian states and even in other bordering countries as eastern Paraguay. The study of the abundant material collected during the last years allowed the description of several new species of the oliveirai complex: T. jurbergi Carcavallo, Galvão Lent, 1998; T. baratai Carcavallo Jurberg, 2000 and T. klugi Carcavallo, Jurberg, Lent Galvão, 2001. Another new species belonging to the same complex is described here as T. vandae sp.n. It originates from the state of Mato Grosso, and has been reared in the insectary of the Laboratório Nacional e Internacional de Referência em Taxonomia de Triatomíneos, Departamento de Entomologia, Instituto Oswaldo Cruz-Fiocruz, Rio de Janeiro.

Differential expression profiles in the midgut of Triatoma infestans infected with Trypanosoma cruzi.

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Diego S Buarque

Full Text Available Chagas disease, or American trypanosomiasis, is a parasitic disease caused by the protozoan Trypanosoma cruzi and is transmitted by insects from the Triatominae subfamily. To identify components involved in the protozoan-vector relationship, we constructed and analyzed cDNA libraries from RNA isolated from the midguts of uninfected and T. cruzi-infected Triatoma infestans, which are major vectors of Chagas disease. We generated approximately 440 high-quality Expressed Sequence Tags (ESTs from each T. infestans midgut cDNA library. The sequences were grouped in 380 clusters, representing an average length of 664.78 base pairs (bp. Many clusters were not classified functionally, representing unknown transcripts. Several transcripts involved in different processes (e.g., detoxification showed differential expression in response to T. cruzi infection. Lysozyme, cathepsin D, a nitrophorin-like protein and a putative 14 kDa protein were significantly upregulated upon infection, whereas thioredoxin reductase was downregulated. In addition, we identified several transcripts related to metabolic processes or immunity with unchanged expressions, including infestin, lipocalins and defensins. We also detected ESTs encoding juvenile hormone binding protein (JHBP, which seems to be involved in insect development and could be a target in control strategies for the vector. This work demonstrates differential gene expression upon T. cruzi infection in the midgut of T. infestans. These data expand the current knowledge regarding vector-parasite interactions for Chagas disease.

Avaliação de óleos essenciais de plantas aromáticas com atividade inseticida em Triatoma infestans (Klug, 1834 (Hemiptera: Reduviidae = Evaluation of essential oils with insecticidal activity in Triatoma infestans (Klug, 1834 (Hemiptera: Reduviidae

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Suellem Petilim Gomes

2011-07-01

Full Text Available A doenca de Chagas e um dos maiores problemas de saude publica na America Latina. Neste trabalho, foi avaliada a acao inseticida de oleos essenciais de Anacardium humile Cymbopogon nardus, Ocimum basilicum e Eucalyptus urograndis em ninfas do 3‹ e 4‹ estadios dedesenvolvimento de Triatoma infestans por acao topica e pressao a vapor (fumigacao. Para o teste topico foram realizadas duas repeticoes cada uma com cinco ninfas de 3‹ e 4‹ estadios de desenvolvimento de T. infestans. Foi aplicado 1ƒÊL de cada concentracao na regiao dorsal de cada individuo. Para o teste de fumigacao foram utilizados potes de 2 L com tampa vedante. Os oleos essenciais de O. gratissimum e E. urograndis apresentaram atividadeinseticida para T. infestans, e A. humile e C. nardus apresentaram em media 5 e 15% de mortalidade, respectivamente. Para fumigacao, somente o oleo de E. urograndis teve efeito, com 100% de mortalidade sobre T. infestans , sendo que para os outros oleos nao foiobservado efeito de fumigacao. Esse trabalho relata pela primeira vez a acao inseticida de E. urograndis em potes fumigenos para o controle de triatomineos. Os resultados sao importantes devido a busca por novos modelos moleculares com acao inseticida em triatomineos resistentes aos inseticidas sinteticos.Chagas disease is a major public health problem in Latin America. This work aimed to evaluate the insecticide action of essential oils of Anacardium humile, Cymbopogon nardus, Ocimum basilicum and Eucalyptus urograndis on Triatoma infestans nymphs of third and fourth stages of development by topic action and steam pressure (fumigation. Two repetitions were performed at the topic test with five nymphs of third and fourth stages of development of T. infestans. It was applied 1ƒÊL of each concentration on the dorsal region of each nymph. Two-liter pots with sealing covers were used at the fumigation test. The essential oils of O. gratissimum and E. urograndis showed insecticidal

Evaluación del efecto insecticida de tierra de diatomeas sobre Triatoma infestans (Hemíptera, Reduviidae

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Mariana L Bilbao

2007-04-01

Full Text Available El Triatoma infestans es el principal vector de la enfermedad de Chagas en Argentina. La tierra de diatomeas (TD es un producto natural que se comercializa actualmente con fines insecticidas y que produce la muerte por deshidratación. Se evaluó la eficacia insecticida de TD al 60% de pureza, proveniente del yacimiento La Iglesiana (San Juan, Argentina sobre ninfas V y adultos de T.infestans. Se ensayaron dos dosis: 112,5 g/m2 (T1 y 225 g/m2 (T2, con cuatro réplicas por tratamiento, con cinco ejemplares, incluyendo los controles (TC en el laboratorio. Se contaron los individuos vivos y muertos durante cinco días. No se encontró diferencias en la mortalidad (ANOVA, p>0,05 en los adultos (T1: 40%, T2: 25% y TC: 30% ni en las ninfas V (T1: 10%, T2: 15% y TC: 10%. Se concluye que la tierra de diatomeas del yacimiento La Iglesiana, en las condiciones de laboratorio evaluadas, no posee capacidad insecticida sobre T.infestans.

Triatoma rubrovaria (Blanchard, 1843 (Hemiptera-Reduviidae-Triatominae III: patterns of feeding, defecation and resistance to starvation

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Carlos Eduardo Almeida

2003-04-01

Full Text Available Data from the Chagas Disease Control Program indicate a growing domiciliary and peridomiciliary invasion of Triatoma rubrovaria in the State of Rio Grande do Sul, where it has become the most frequent triatomine species captured there since the control of T. infestans. Bionomic characteristics that could influence the vectorial capacity of T. rubrovaria as vector of Trypanosoma cruzi were evaluated: patterns of (i feeding, (ii defecation, and (iii resistance to starvation, using insects fed on mice. Fifty three percent of the females showed a defecation pattern conducive to chagasic transmission, defecating either on or near the bite site. The averages of the resistance to starvation varied from 48.1 to 179 days, for the first and fifth nymphal stages, respectively. Our study shows that with respect to the patterns of feeding, defecation and resistance to fasting, T. rubrovaria presented similar rates to the ones observed for other effective vector species, such as T. infestans. Thus, based on our studies we conclude that T. rubrovaria has biological characteristics that can positively influence its capacity to become infected and transmit T. cruzi, and also to keep residual populations after chemical control interventions.

Risk of domiciliation of Triatoma williami Galv ão, Souza e Lima, 1965 in a municipality of Brazilian Legal Amazon region

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Octavio André de Andrade-Neto

2012-05-01

Full Text Available Objective: To notify the positivity and presence of vectors in natural and artificial ecotopes and analyze the basic knowledge of the Chagas disease vectors among population of amazon legal municipality. Methods: The molecular confirmation of the parasite species was by PCR using species-specific markers. Data collection was conducted using semi-structured interviews. Results: All of 34 specimens collected were classified to be a single species, Triatoma williami. The natural infection rate of vectors in the specimens by T. cruzi was 30%. Most interviewees recognized adult triatomines. For 24.43% of respondents who had found the vector inside the house the main practice reported was killing the insects by crushing. Conclusions: Despite the knowledge shown by the residents, educational measures are needed to improve entomological surveillance of Chagas disease into enzootic amazon area.

Experimental control of Triatoma infestans in poor rural villages of Bolivia through community participation.

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Lardeux, Frédéric; Depickère, Stéphanie; Aliaga, Claudia; Chavez, Tamara; Zambrana, Lilian

2015-02-01

Triatoma infestans is the main vector of Chagas disease in the southern cone countries. Present control strategies based on indoor and outdoor residual insecticide spraying are not sufficient to control disease transmission, particularly in Bolivia. Techniques based on the management of the human environment may be good alternatives or supplements. Social and entomological surveys were carried out in four villages of Bolivia situated in the dry inter-Andean Valleys and the Chaco region. Risk factors for house infestation by T. infestans were identified, and an eco-health intervention based on education and community participation was carried out to reduce the risks of house infestation. It consisted of implementing simple and low cost vector control techniques such as coating of mud walls, cleaning activities and removal of poultry that enter rooms to lay eggs. The eco-health intervention significantly reduced the number of infested bedrooms, the mean abundance of T. infestans in bedrooms and beds, especially in the Chaco region. Mud wall coating was well accepted and could be proposed as a supplementary tool to the National Program of Chagas Disease Control to enhance the effects of insecticide sprayings. Even if cleaning activities were still neglected, community participation proved to be effective in reducing house infestation. © The author 2015. The World Health Organization has granted Oxford University Press permission for the reproduction of this article.

An updated insight into the Sialotranscriptome of Triatoma infestans: developmental stage and geographic variations.

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Alexandra Schwarz

2014-12-01

Full Text Available Triatoma infestans is the main vector of Chagas disease in South America. As in all hematophagous arthropods, its saliva contains a complex cocktail that assists blood feeding by preventing platelet aggregation and blood clotting and promoting vasodilation. These salivary components can be immunologically recognized by their vector's hosts and targeted with antibodies that might disrupt blood feeding. These antibodies can be used to detect vector exposure using immunoassays. Antibodies may also contribute to the fast evolution of the salivary cocktail.Salivary gland cDNA libraries from nymphal and adult T. infestans of breeding colonies originating from different locations (Argentina, Chile, Peru and Bolivia, and cDNA libraries originating from F1 populations of Bolivia, were sequenced using Illumina technology. Coding sequences (CDS were extracted from the assembled reads, the numbers of reads mapped to these CDS, sequences were functionally annotated and polymorphisms determined.Over five thousand CDS, mostly full length or near full length, were publicly deposited on GenBank. Transcripts that were over 10-fold overexpressed from different geographical regions, or from different developmental stages were identified. Polymorphisms were mapped to derived coding sequences, and found to vary between developmental instars and geographic origin of the biological material. This expanded sialome database from T. infestans should be of assistance in future proteomic work attempting to identify salivary proteins that might be used as epidemiological markers of vector exposure, or proteins of pharmacological interest.

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

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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.

Avaliação de óleos essenciais de plantas aromáticas com atividade inseticida em Triatoma infestans (Klug, 1834 (Hemiptera: Reduviidae Evaluation of essential oils with insecticidal activity in Triatoma infestans (Klug, 1834 (Hemiptera: Reduviidae

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Silvio Favero

2011-09-01

Full Text Available A doença de Chagas é um dos maiores problemas de saúde pública na América Latina. Neste trabalho, foi avaliada a ação inseticida de óleos essenciais de Anacardium humile Cymbopogon nardus, Ocimum basilicum e Eucalyptus urograndis em ninfas do 3° e 4° estádios de desenvolvimento de Triatoma infestans por ação tópica e pressão a vapor (fumigação. Para o teste tópico foram realizadas duas repetições cada uma com cinco ninfas de 3° e 4° estádios de desenvolvimento de T. infestans. Foi aplicado 1µL de cada concentração na região dorsal de cada indivíduo. Para o teste de fumigação foram utilizados potes de 2 L com tampa vedante. Os óleos essenciais de O. gratissimum e E. urograndis apresentaram atividade inseticida para T. infestans, e A. humile e C. nardus apresentaram em média 5 e 15% de mortalidade, respectivamente. Para fumigação, somente o óleo de E. urograndis teve efeito, com 100% de mortalidade sobre T. infestans, sendo que para os outros óleos não foi observado efeito de fumigação. Esse trabalho relata pela primeira vez a ação inseticida de E. urograndis em potes fumígenos para o controle de triatomíneos. Os resultados são importantes devido à busca por novos modelos moleculares com ação inseticida em triatomíneos resistentes aos inseticidas sintéticos.Chagas disease is a major public health problem in Latin America. This work aimed to evaluate the insecticide action of essential oils of Anacardium humile, Cymbopogon nardus, Ocimum basilicum and Eucalyptus urograndis on Triatoma infestans nymphs of third and fourth stages of development by topic action and steam pressure (fumigation. Two repetitions were performed at the topic test with five nymphs of third and fourth stages of development of T. infestans. It was applied 1µL of each concentration on the dorsal region of each nymph. Two-liter pots with sealing covers were used at the fumigation test. The essential oils of O. gratissimum and E

Técnica para a observação do comportamento do Triatoma infestans (Klug, 1834 em uma miniatura de casa de pau-a-pique e sapê Technic for the observation of the behavior of Triatoma infestans (Klug, 1834 in a miniature of a mud-walled and tatch roofed house

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José Roberto Mac Cord

1983-06-01

Full Text Available Com o objetivo de observar e registrar o comportamento do Triatoma infestans quanto a movimentos, posturas e estados fisiológicos, como preconizam os etólogos, foi construída uma réplica de uma casa de paua-pique e sapê com uma proteção externa de acrílico transparente. Para o registro das atividades empregou-se a cinematografia com lapso de tempo, através de uma filmadora super-8 sincronizada a um flash eletrônico e programada para disparos simultâneos de 1 fotograma a cada 30 segundos. A análise dos dados foi feita com um projetor super-8 e um editor, que permitiu observar cada fotograma. Com um período de registros durante 6 dias ininterruptos, os resultados permitiram concluir que: a na ausência de estímulo alimentar, não ocorre atividade locomotora no T. infestans, independente de ser dia ou noite, mesmo com o inseto privado de alimentos; b em presençaa do estímulo alimentar a atividade locomotora ocorre durante as 24 horas do dia, embora em proporção significantemente maior no período de obscuridade.In order to observe and record the behaviour of Triatoma infestans in relation to movement, position and physiological state, like the ethologists commend, a mud-walled thatch roofed house within an external transparent acrilic protection was built. To record the bug activity a time-lapse cinematographic tecnique using a super-8 mm movie camera synchronized to and eletronic flash and programmed for simultaneous shots of one photograph every 30 seconds was employed. The analysis of the data was done with super-8 mm film projector and a movieola editor which allowed the observation of each photograph. After six days of continous observation by this method the following statements could be made: a In the absence of the alimentary stimulus the locomotory activity in T. investans does not occur, being day or night, even if the insect is deprived of its blood-meal, b In presence of an alimentary stimulus the locomotory activity

Estadísticos poblacionales de Triatoma sordida Stäl 1859 (Hemiptera : Reduviidae en condiciones experimentales Population statistics of Triatoma sordida Stäl 1859 (Hemiptera: Reduviidae in experimental conditions

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Elena B. Oscherov

1996-10-01

Full Text Available Se realizó el seguimiento longitudinal de cuatro cohortes de 100 huevos cada una. Los insectos fueron criados a 28°C ± 3°C y 63 % ± 10% de humedad relativa, y alimentados cada siete días sobre gallina (Gallus domesticus, durante 40 min. Las cohortes fueron controladas una vez por semana. Se observó un valor constante de supervivencia en las cuatro cohortes, sin picos importantes. La expectativa de vida de los machos, en promedio, fue de 37,4 semanas y la de las hembras 36,8. El tiempo generacional demandó 61,7 semanas. La tasa reproductiva neta indica que esta población se incrementará 143,3 veces con cada generación. La tasa intrínseca de crecimiento natural fue de 0,082 por semana. El máximo valor reproductivo se verificó, en promedio, a la tercer semana del ingreso al estado adulto. La distribución estable de edades de T. sordida sería de 32% huevos, 26% ninfas de primer estadio, 19% ninfas de segundo estadio, 13% ninfas de tercer estadio, 6% ninfas de cuarto estadio, 3% ninfas de quinto estadio y 1% de adultos. Es la primera cita para Argentina sobre la tabla de vida de T. sordida. El análisis de estos parámetros permite considerar que esta especie se comporta como "K estratega", en condiciones experimentales.Foram estudados diferentes parâmetros populacionais de Triatoma sordida em condições de laboratório. Realizou-se um seguimento longitudinal de quatro coortes de 100 ovos cada uma; os insetos foram criados a 28°C ± 3°C e 63% ± 10% de umidade relativa, e alimentados cada sete dias sobre galinha (Gallus domesticus durante 40'. As coortes foram controladas uma vez por semana. A expectativa de vida média dos machos foi de 37,4 semanas e a das fêmeas de 36,8.O tempo médio de desenvolvimento foi de 61,7 semanas. A taxa reprodutiva líquida indica que esta população aumentará 143,2 vezes durante cada geração. A taxa intrínseca do crecimento natural foi de 0,082 por semana. A média do valor máximo reprodutivo

Hábito alimentar de Triatoma vitticeps no Estado do Rio de Janeiro, Brasil

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Gonçalves Teresa Cristina M

2000-01-01

Full Text Available OBJETIVO: O estudo do hábito alimentar dos triatomíneos tem contribuído para o conhecimento da sua biologia no habitat natural. Triatoma vitticeps, espécie que vem invadindo freqüentemente o domicílio apresentando-se infectado por T. cruzi, foi analisado sob esse aspecto, possibilitando conhecer a situação epidemiológica da área. MÉTODOS: De fevereiro de 1989 a abril de 1993, 122 espécimes de T. vitticeps foram capturados em duas áreas da localidade de Triunfo, 2° Distrito do Município de Santa Maria Madalena (RJ. Os insetos foram dissecados para a retirada do conteúdo estomacal. Os anti-soros utilizados foram: homem, vaca, cavalo, cão, porco, tatu, gambá, roedor e ave. RESULTADOS: Do total analisado, 79 estavam positivos e 43 negativos para os anti-soros testados: tatu (30,3% > homem e porco (13,1% > ave e cão (11,5% > cavalo (5,7% > gambá (4,9% > roedor (4,1% > boi (3,3%. As fontes alimentares identificadas variaram de 1 a 4 e 6: 0 - 25,41%; 1 - 45,08%; 2 - 10,66%; 3 - 6,56%; 4 - 1,64% e 6 - 0,82%. Quanto à infecção por T. cruzi, 74 espécimes (65,54% estavam positivos, 39 (34,51% negativos e 9 não foram examinados. CONCLUSÕES: Os resultados caracterizam o hábito silvestre de T. vitticeps e a tripanosomíase como uma enzootia. A vigilância epidemiológica se faz necessária para o acompanhamento do comportamento dessa espécie.

Factors associated with the occurrence of Triatoma sordida (Hemiptera: Reduviidae in rural localities of Central-West Brazil

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Juliana Chedid Nogared Rossi

2015-04-01

Full Text Available This study estimates the factors of artificial environments (houses and peridomestic areas associated with Triatoma sordida occurrence. Manual searches for triatomines were performed in 136 domiciliary units (DUs in two rural localities of Central-West Brazil. For each DU, 32 structural, 23 biotic and 28 management variables were obtained. Multiple logistic regression analysis was performed in order to identify statistically significant variables associated with occurrence of T. sordida in the study areas. A total of 1,057 specimens (99% in peridomiciles, mainly chicken coops of T. sordida were collected from 63 DUs (infestation: 47%; density: ~8 specimens/DU; crowding: ~17 specimens/infested DU; colonisation: 81%. Only six (0.6% out of 945 specimens examined were infected with Trypanosoma cruzi. The final adjusted logistic regression model indicated that the probability of T. sordida occurrence was higher in DU with wooden chicken coops, presence of > 30 animals in wooden corrals, presence of wood piles and presence of food storeroom. The results show the persistence of T. sordida in peridomestic habitats in rural localities of Central-West Brazil. However, the observed low intradomestic colonisation and minimal triatomine infection rates indicate that T. sordida has low potential to sustain high rates of T. cruzi transmission to residents of these localities.

Potential sources of Triatoma infestans reinfesting peridomiciles identified by morphological characterization in Los Llanos, La Rioja, Argentina

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María Laura Hernández

2013-02-01

Full Text Available The presence of Triatoma infestans in habitats treated with insecticides constitutes a frequent problem in endemic areas. Basing our study on the hypothesis that descendants of a residual population should be more similar to the pre-treatment population than to any other, we compared the indications of two quantitative morphological approaches. This study seeks to find the origin of 247 T. infestans from three populations found in two chicken coops and a goat corral after treatment with insecticides. The results obtained by quantitative morphology suggest that the T. infestans found between three-34 months after the application of insecticides formed mixed populations with insects derived from residual foci and neighbouring habitats. Our analyses also showed the presence of a phenotype which does not resemble neither the pre-treatment phenotype nor the one from neighbouring populations, suggesting the presence of a particular post-treatment phenotype. The heads size showed some variations in males from different populations and remained unchanged in females, which reinforces the hypothesis of an intraspecific competition for food with priority for females. This article presents, for the first time, the combined analysis of geometric morphometry of heads and antennal phenotypes to identify the composition of reinfesting populations.

Hemi-nested PCR and RFLP methodologies for identifying blood meals of the Chagas disease vector, Triatoma infestans.

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Roellig, Dawn M; Gomez-Puerta, Luis A; Mead, Daniel G; Pinto, Jesus; Ancca-Juarez, Jenny; Calderon, Maritza; Bern, Caryn; Gilman, Robert H; Cama, Vitaliano A

2013-01-01

Trypanosoma cruzi, the etiologic agent of Chagas disease, is transmitted by hematophagous reduviid bugs within the subfamily Triatominae. These vectors take blood meals from a wide range of hosts, and their feeding behaviors have been used to investigate the ecology and epidemiology of T. cruzi. In this study we describe two PCR-based methodologies that amplify a fragment of the 16S mitochondrial rDNA, aimed to improve the identification of blood meal sources for Triatoma infestans: a.--Sequence analyses of two heminested PCRs that allow the identification of mammalian and avian species, and b.--restriction fragment length polymorphism (RFLP) analysis from the mammalian PCR to identify and differentiate multi-host blood meals. Findings from both methodologies indicate that host DNA could be detected and the host species identified in samples from laboratory reared and field collected triatomines. The implications of this study are two-fold. First, these methods can be used in areas where the fauna diversity and feeding behavior of the triatomines are unknown. Secondly, the RFLP method led to the identification of multi-host DNA from T. infestans gut contents, enhancing the information provided by this assay. These tools are important contributions for ecological and epidemiological studies of vector-borne diseases.

Fontes alimentares de Triatoma pseudomaculata no Estado do Ceará, Brasil

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Simone Patrícia Carneiro Freitas

2005-01-01

Full Text Available OBJETIVO: Triatoma pseudomaculata, espécie peridomiciliar, é encontrada apresentando baixa taxa de infecção por Trypanosoma cruzi. Com o objetivo de identificar os possíveis reservatórios de T. cruzi, investigou-se a ocorrência desse triatomíneo no domicílio, bem como suas fontes alimentares. MÉTODOS: De janeiro de 2001 a julho de 2002 foram capturados 921 espécimes de T. pseudomaculata em 13 municípios do sul do Estado do Ceará. O conteúdo intestinal dos triatomíneos foi retirado, espalhado em disco de papel de filtro e analisado por precipitina para os seguintes anti-soros: ave, roedor, cão, gambá, lagarto, boi/cabra, gato, porco, barata e humano. A investigação da presença de T. cruzi foi feita observando-se parte do conteúdo intestinal dos insetos a fresco, entre lâmina e lamínula, e pela sua semeadura em meio de cultura. RESULTADOS: Do total examinado, 184 (90,6% foram positivos para os anti-soros testados: ave (62,5%> roedor (33,7%> cão (20,1%> gambá (9,8%> lagarto (5%> boi-cabra (5%> gato (2,7%> porco (2,2%> barata (2,2%> humano (1,6%. As alimentações variaram de zero (não reagiram a quatro da seguinte forma: não reagiram (9,4%, uma (57,1%, duas (26%, três (7% ou quatro (0,5%. Das fontes alimentares identificadas apenas três espécimes (1,6% foram positivos para T. cruzi. CONCLUSÕES: A baixa incidência de sangue humano mostra que T. pseudomaculata está bem adaptado ao peridomicílio. Porém, a vigilância epidemiológica na região sul do Estado do Ceará se faz necessária tendo em vista a proximidade da espécie ao domicílio.

Infestacion domestica por triatoma infestans y prevalencia de seropositivos al Trypanosoma cruzi en un area rural del nordeste argentino

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M. Esther Bar

1996-12-01

Full Text Available Se llevó a cabo un estúdio epidemiológicopara obtener unpanorama general de la transmisión doméstica del Trypanosoma cruzi en áreas rurales del Departamento San Miguel, Conientes, Argentina. Se investigaron 100 viviendas precarias, 50,0% de las mismas resultó infestado por Triatoma infestans y 1,0% por T. sórdida, citãndose por primera vez para la provinda de Comentes la colonización domiciliaria de esta especie. El 23,1% de T. infestans estaba infectado por T. cruzi. La seroprevalencia de 388 pacientes analizados por hemaglutinacíôn indirecta e inmunofluorescencia indirecta fue 23,4%, destacándose el alto índice (12,9% constatado en menores de 10 anos. Losporcentajes de seropositividad aumentaron con la edad, alcanzándose 50,0% de infectados entre los 31-40 anos. La infestación doméstica por T. infestans, la prevalencia humana de seropositivos al T. cruzi y las condiciones deprecariedad en que se desenvuelve la vida de los pobladores revelan la vigência de la endemia chagãsica en el área estudiada.

Inheritance and heritability of deltamethrin resistance under laboratory conditions of Triatoma infestans from Bolivia.

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Gomez, Marinely Bustamante; Pessoa, Grasielle D'Avila Caldas; Rosa, Aline Cristine Luiz; Echeverria, Jorge Espinoza; Diotaiuti, Liléia Gonçalves

2015-11-16

Over the last few decades, pyrethroid-resistant in Triatoma infestans populations have been reported, mainly on the border between Argentina and Bolivia. Understanding the genetic basis of inheritance mode and heritability of resistance to insecticides under laboratory conditions is crucial for vector management and monitoring of insecticide resistance. Currently, few studies have been performed to characterize the inheritance mode of resistance to pyrethroids in T. infestans; for this reason, the present study aims to characterize the inheritance and heritability of deltamethrin resistance in T. infestans populations from Bolivia with different toxicological profiles. Experimental crosses were performed between a susceptible (S) colony and resistant (R) and reduced susceptibility (RS) colonies in both directions (♀ x ♂ and ♂ x ♀), and inheritance mode was determined based on degree of dominance (DO) and effective dominance (D(ML)). In addition, realized heritability (h(2)) was estimated based on a resistant colony, and select pressure was performed for two generations based on the diagnostic dose (10 ng. i. a. /nymph). The F1 progeny of the experimental crosses and the selection were tested by a standard insecticide resistance bioassay. The result for DO and D(ML) (Bolivia. The lethal doses (LD50) increase from one generation to another rapidly after selection pressure with deltamethrin. This suggests that resistance is an additive and cumulative factor, mainly in highly structured populations with limited dispersal capacity, such as T. infestans. This phenomenon was demonstrated for the first time for T. infestans in the present study. These results are very important for vector control strategies in problematic areas where high resistance ratios of T. infestans have been reported.

Relação entre Triatoma infestans, aves domésticas e o homem num povoado de Santiago del Estero, Argentina The relationship between Triatoma infestans, poultry, and humans in a rural settlement in Santiago del Estero, Argentina

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Patrícia P. Gajate

1994-03-01

Full Text Available Determinou-se a associação entre Triatoma infestans, aves domésticas e o homem no povoado de Trinidad, Santiago del Estero, Argentina. Para coletar triatomíneos foram realizadas quatro amostragens no peridomicílio de seis casas, utilizando-se o método de captura hora/homem (dezembro de 1991 a outubro de 1992. Os anexos foram classificados em antrópicos (onde o homem realiza atividades cotidianas e não-antrópicos. Além disso, determinou-se o perfil alimentar dos barbeiros. De um total de 134 ecótopos investigados, 21% tinham T. infestans; 22% possuíam aves domésticas; e 54% eram antrópicos. Em 25% destes ecótopos foram encontradas aves e T. infestans simultaneamente. As aves foram os únicos animais domésticos associados com o T. infestans, sendo que esta relação só ocorreu nos ecótopos antrópicos. A proporção de ingestas em aves (61/146 foi altamente significativa. Em Trinidad não há galinheiros, utilizando-se, assim, os anexos entrópicos do peridomicílio como local para se construir os ninhos para as aves. tanto pelos elementos usados na preparação dos ninhos como pelo uso posterior dos mesmos, poder-se-ia estabelecer um fluxo periódico de barbeiros do intradomicílio para o peridomicílio, e vice-versa, através do transporte passivo. Esta relação estreita entre Triatoma infestans, aves domésticas e o homem, encontrada nos ecótopos antrópicos, onde também existem outros reservatórios de T. cruzi, como os cães, favorece a manutenção de colônias de barbeiros domiciliares e a transmissão da doença de Chagas ao homem.An association was determined between Triatona infestans, poultry, and humans in Trinidad, in the Province of Santiago del Estero, Argentina. To collect triatomines, four samples were taken at the area immediately surrounding six houses by the one hour/man capture method (December 1991 - October 1992. Peridomiciliary ecotopes were classified as arthropic (where humans carry out daily

Factors limiting the domestic density of Triatoma infestans in north-west Argentina: a longitudinal study.

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Cecere, M C; Gürtler, R E; Chuit, R; Cohen, J E

1998-01-01

Reported are the environmental and demographic risk factors associated with the domestic infestation and density of Triatoma infestans in three heavily infested rural villages in Santiago del Estero Province, Argentina. In a one-factor unadjusted analysis, the number of T. infestans captured per person-hour was associated significantly and negatively with the use of domestic insecticides by householders, type of thatch used in the roofs and the age of the house; and positively with the following: degree of cracking of the indoor walls and presence of hens nesting indoors. In one model, using multiple linear regression and a backward stepwise elimination procedure, most of the variation in the overall abundance of T. infestans was explained by insecticide use and the presence of hens nesting indoors; in another model using the same procedure it was explained by insecticide use, bug density in 1988 and previous spraying with deltamethrin in 1985. Variations in bug density per capture stratum (household goods, beds, walls and roof) were explained by the bug density in other strata and by one or two of the following risk factors: hens nesting indoors, type of roof, presence of cracks in the walls and number of people living in the house. Bug density might be locally controlled by the availability of refuges in the roofs and walls, by the presence of hens nesting indoors and by the use of domestic insecticides. Certain local materials, such as a grass known as simbol, could be successfully used in rural housing improvement programmes aimed at reducing the availability of refuges for insects in the roof.

First record of Triatoma maculata (Erichson, 1848 (Hemiptera: Reduviidae: Triatomini in Riohacha, La Guajira – Colombia

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Edith Natalia Gómez-Melendro

2014-11-01

Full Text Available Introduction. Knowledge of vector insect species, their habitat and geographical distribution is crucial for determining the risk of transmission of the etiologic agents that cause disease in humans, which allows defining strategies for prevention, surveillance and control in line with the characteristics of each area. Objective. To determine the presence and public health importance of vectors of Chagas disease in the indigenous settlements of Marbacella and El Horno of the Wayúu ethnic group in the municipality of Riohacha, La Guajira, Colombia. Materials and methods. From active search, installation and inspection of biosensors and occasional catches, Hemiptera: Reduviidae: Triatomini were collected intra and in the peridomicile housing of the indigenous settlements of El Horno and Marbacella of the the Wayúu ethnic group. Indices of intra and peridomestic infestation, colonization, density, dispersion and natural infection with Trypanosoma cruzi Chagas, 1909 were calculated. Results. 79.6% (n = 90 of the specimens were collected around the homes and 20.3% (n = 23 inside the homes, all corresponding to Triatoma maculata (Erichson, 1848. The natural infection indices with T. cruzi accounted for 43.5% for Marbacella and 36% for El Horno. Conclusion. This is the first reported capture of individuals of T. maculata, considered a secondary vector of Chagas disease in Colombia, naturally infected with T. cruzi in the municipality of Riohacha expanding the geographical distribution of the species in the department of La Guajira.

Toxicological profile of deltamethrin in Triatoma brasiliensis (Hemiptera: Reduviidae) in State of Ceará, Northeastern Brazil.

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Pessoa, Grasielle Caldas D'Ávila; Trevizani, Nathália Abreu Borges; Dias, Letícia Sena; Bezerra, Claudia Mendonça de; Melo, Bernardino Vaz de; Diotaiut, Liléia

2015-01-01

Triatoma brasiliensis is the species of greatest epidemiological relevance in the semi-arid region of Brazil. This species is predominantly found in domestic environments, and it has the ability to build large colonies with high levels of natural infection via Trypanosoma cruzi. Thus, T. brasiliensis is one of the most efficient transmitters of Chagas disease (CD) to humans. Despite household spraying with residual insecticides, many areas report persistent reinfestations for reasons that remain poorly understood. Therefore, this study sought to characterize the toxicological profile of deltamethrin in T. brasiliensis from areas with persistent reinfestation in State of Ceará, Brazil. The susceptibility reference lineage (SRL) was derived from Umari. Serial dilutions of deltamethrin were prepared and applied to the dorsal abdomen of first instar nymphs. The control group received only pure acetone. Mortality was evaluated after 72h. Qualitative tests assessed mortality in response to a diagnostic dose of 1xLD99 (0.851 nanograms of active ingredient per treated nymph) of the SRL. The susceptibility profile characterization of the T. brasiliensis populations revealed 50% resistance ratios (RR50) that ranged from 0.32 to 1.21. The percentage of mortality in response to the diagnostic dose was 100%. We demonstrated that T. brasiliensis was highly susceptible to deltamethrin. The control difficulties found might be related to the recolonization of the triatomines originating from neighboring environments and the possible operational failures related to the process of spraying that enabled specimens less susceptible to deltamethrin to survive.

Domestic vectors of Chagas' disease in three rural communities of Nicaragua Vectores domesticos de la Enfermedad de Chagas en tres comunidades endémicas de Nicarágua

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Rosário Palma-Guzmán

1996-04-01

Full Text Available A triatomine survey was conducted in three rural settlements of Nicaragua (Santa Rosa, Quebrada Honda and Poneloya where Chagas' disease is endemic, to determine rates of house infestation, evaluate the housing condition and to asess the performance of the María sensor box in detection of domestic vectors. A total of 184 households were selected and vectors were sought by the methods of timed manual capture and by sensor boxes. The sole vectors species found in this study was Triatoma dimidiata. Of the examined bugs 50, 60 and 33%, in the respective communities, were infected with T. cruzi. The rates of house infestation as determined by manual capture and sensor boxes were respectively, 48.3% and 54.2% in Santa Rosa, 29.8% and 51.2% in Quebrada Honda and in Poneloya 3.8 and 5.9% with significant difference between the methods in Quebrada Honda. When compared with the manual capture, the Maria sensor box detected vectors in 71.4% of positive houses in two of the communities but also was able to detect bugs in 39.3% and 41.1% of houses where manual capture had been negative. Housing condition was evaluated according to three structural parameters, in this way, in the first community 79.2% of houses were classified as bad, 20.8% as regular; in the second one 42.5% were bad and 57.5% regular, whereas in the third 62.5% of the houses were regular. Rates of infestation did not differ greatly between the different housing conditions. Our results show that the sensor box is as efficient as manual capture and could be implemented in our country.Se efectuó una encuesta de vectores de la enfermedad de Chagas en tres comunidades endémicas de Nicaragua (Santa Rosa, Quebrada Honda y Poneloya para medir las tasas de infestación domiciliar, evaluar la condición de las viviendas, y determinar la eficacia del biosensor María para detectar los vectores domésticos. Se seleccionaron un total de 184 casas y los vectores se buscaron por los métodos de captura

Active dispersal of Triatoma infestans and other triatomines in the Argentinean arid Chaco before and after vector control interventions.

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Abrahan, Luciana; Gorla, David; Catalá, Silvia

2016-06-01

Peridomestic structures are considered the main sites where Triatoma infestans (Hemiptera: Reduviidae) remain and disperse, representing the first risk factor for intradomestic invasion, even after vector control activities. This study analyzed T. infestans dispersal during vector control interventions in six rural houses of the arid Chaco (La Rioja, Argentina). Flying and walking dispersers were captured during five months of two consecutive warm seasons after insecticide spraying of intra- and peridomiciles. These data were compared with previous published data in the same scenario but without insecticide spraying in peridomiciles. Recorded climatic conditions were favorable for active dispersion during the study. Total number of T. infestans dispersers moving among domestic habitats decreased after insecticide spraying. Sylvatic triatomines T. guasayana, T. eratyrusiformis, T. garciabesi, and T. platensis, not targeted by insecticide spraying, were captured simultaneously within peridomestic areas and showed higher invasion pressure than T. infestans. Adult T. infestans peridomestic populations showed high nutritional status, indicating low dispersion probability. Some peridomiciles remained infested at the end of the study. However, no intradomiciles were recolonized. These results suggest that there is a low probability of intradomestic recolonization by active dispersion from peridomiciles during 15 months post-spraying. © 2016 The Society for Vector Ecology.

Triatoma sordida Stål 1859 (Hemiptera, Reduviidae: Triatominae in palms of northeastern Argentina

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Bar María Esther

2001-01-01

Full Text Available Several palms species provide an important habitat for triatomines and associate vertebrates in tropical America. The objective of this work is to identify the triatomine species living in the palms of rural areas in the Province of Corrientes, and to estimate the potential epidemiological risk they represent for the residents of nearby houses. The survey was carried out in a palm community in Colonia Laurel, Department San Roque, Province of Corrientes, Argentina. Samplings were performed in October, November and December 1998; January, February and March 1999; May and June 1999. Thirty palms: 27 (90% Butia yatay (Mart. Becc. and 3 Acrocomia aculeata (Jacq. Lodd ex Mart. were dissected. Triatoma sordida Stål 1859 was found in 96.2% of B. yatay and in all the A. aculeata palms. A total of 272 live T. sordida was collected; 36 of them (13.2% were found in bird nests in the frond and the remainder in other locations of the tree. The mean number of triatomines per palm was 9.6 (range 1-60, mode 2. T. sordida was collected during all the sampling months and all stages were present at all seasons. The highest population density was reached in spring and the lowest in autumn. Trypanosoma cruzi was detected in 38.5% in feces of 174 examined insects and identified as such, both by microscopical examination and PCR. This is the first finding of T. sordida populations in B. yatay, an endemic palm of South America distributed in southern Brazil, Uruguay and northeastern Argentina. The high infection prevalence found in this work suggests that T. sordida plays an essential role in the maintenance of the wild T. cruzi transmission cycle in northeastern Argentina.

Life cycle and reproductive patterns of Triatoma rubrovaria (Blanchard, 1843 (Hemiptera: Reduviidae under constant and fluctuating conditions of temperature and humidity

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Damborsky Miryam P.

2005-01-01

Full Text Available The aim of this study was to evaluate the temperature and relative humidity influence in the life cycle, mortality and fecundity patterns of Triatoma rubrovaria. Four cohorts with 60 recently laid eggs each were conformed. The cohorts were divided into two groups. In the controlled conditions group insects were maintained in a dark climatic chamber under constant temperature and humidity, whereas triatomines of the ambiental temperature group were maintained at room temperature. Average incubation time was 15.6 days in the controlled conditions group and 19.1 days in the ambiental temperature. In group controlled conditions the time from egg to adult development lasted 10 months while group ambiental temperature took four months longer. Egg eclosion rate was 99.1% and 98.3% in controlled conditions and ambiental temperature, respectively. Total nymphal mortality in controlled conditions was 52.6% whereas in ambiental temperature was 51.8%. Mean number of eggs/female was 817.6 controlled conditions and 837.1 ambiental temperature. Fluctuating temperature and humidity promoted changes in the life cycle duration and in the reproductive performance of this species, although not in the species mortality.

Macrogeographic and microgeographic genetic structure of the Chagas' disease vector Triatoma infestans (Hemiptera: Reduviidae) from Catamarca, Argentina.

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Pérez de Rosas, Alicia R; Segura, Elsa L; Fichera, Laura; García, Beatriz Alicia

2008-07-01

The genetic structure in populations of the Chagas' disease vector Triatoma infestans from six localities belonging to areas under the same insecticide treatment conditions of Catamarca province (Argentina) was examined at macrogeographical and microgeographical scales. A total of 238 insects were typed for 10 polymorphic microsatellite loci. The average observed and expected heterozygosities ranged from 0.319 to 0.549 and from 0.389 to 0.689, respectively. The present results confirm that populations of T. infestans are highly structured. Spatial genetic structure was detectable at macrogeographical and microgeographical levels. Comparisons of the levels of genetic variability between two temporal samples were carried out to assess the impact of the insecticide treatment. The genetic diversity of the population was not significantly affected after insecticide use since different genetic parameters (allele number, observed and expected heterozygosities) remained stable. However, loss of low frequency alleles and not previously found alleles were detected. The effective population size (N(e)) estimated was substantially lower in the second temporal sample than in the first; nevertheless, it is possible that the size of the remnant population after insecticide treatment was still large enough to retain the genetic diversity. Very few individuals did not belong to the local T. infestans populations as determined by assignment analyses, suggesting a low level of immigration in the population. The results of the assignment and first-generation migrant tests suggest male-biased dispersal at microgeographical level.

Toxicological profile of deltamethrin in Triatoma brasiliensis (Hemiptera: Reduviidae in State of Ceará, Northeastern Brazil

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Grasielle Caldas D'Ávila Pessoa

2015-02-01

Full Text Available INTRODUCTION: Triatoma brasiliensis is the species of greatest epidemiological relevance in the semi-arid region of Brazil. This species is predominantly found in domestic environments, and it has the ability to build large colonies with high levels of natural infection via Trypanosoma cruzi. Thus, T. brasiliensis is one of the most efficient transmitters of Chagas disease (CD to humans. Despite household spraying with residual insecticides, many areas report persistent reinfestations for reasons that remain poorly understood. Therefore, this study sought to characterize the toxicological profile of deltamethrin in T. brasiliensis from areas with persistent reinfestation in State of Ceará, Brazil. METHODS: The susceptibility reference lineage (SRL was derived from Umari. Serial dilutions of deltamethrin were prepared and applied to the dorsal abdomen of first instar nymphs. The control group received only pure acetone. Mortality was evaluated after 72h. Qualitative tests assessed mortality in response to a diagnostic dose of 1xLD99 (0.851 nanograms of active ingredient per treated nymph of the SRL. RESULTS: The susceptibility profile characterization of the T. brasiliensis populations revealed 50% resistance ratios (RR50 that ranged from 0.32 to 1.21. The percentage of mortality in response to the diagnostic dose was 100%. CONCLUSIONS: We demonstrated that T. brasiliensis was highly susceptible to deltamethrin. The control difficulties found might be related to the recolonization of the triatomines originating from neighboring environments and the possible operational failures related to the process of spraying that enabled specimens less susceptible to deltamethrin to survive.

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

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Mauro Pereira Barreto

1976-12-01

Full Text Available Com base em seu comportamento ecológico e seu grau de relacionamento com o homem e os mamíferos domésticos, comensais e sinantrópicos, os triatomíneos são distribuídos em seis grupos: 1 Triatomíneos tipicamente silvestres, isto é, espécies só encontradas em ecótopos naturais e que nunca freqüentam as habitações humanas e suas dependências. Conseqüentemente, nunca entram em contacto com o homem e os mamíferos domésticos, a não ser acidentalmente quando estes penetram nos focos naturais. Entretanto, podem ter papel maior ou menor na manutenção da enzootia tripanossômica silvestre. Exemplos: Psammolestes coreodes, Psammolestes tertius, Cavernicola pilosa, Triatoma dispar, Triatoma delpontei e muitas outras espécies cujos hábitos são pouco conhecidos. 2 Triatomíneos essencialmente silvestres cujos adultos invadem, com maior ou menor freqüência, as habitações humanas e suas dependências, sem, todavia, aqui se colonizar. Além do papel que têm no ciclo silvestre de transmissão do T. cruzi, podem, ao entrar em contacto com o homem e os mamíferos domésticos e domiciliados suscetíveis, transmitir-lhes a infecção, tanto em áreas silvestres quanto em ecótopos artificiais. Exemplos: Panstrongylus geniculatus, Triatoma rubrovaria,Triatoma arthumeivai, Triatoma patagonica, Triatoma eratyrusiforme, Rhodnius domesticus e muitas outras espécies cujos hábitos são poucos conhecidos. 3 Triatomíneos silvestres em fase inicial de adaptação aos ecótopos artificiais, formando pequenas colônias principalmente no peridomicílio e, mais raramente, na própria habitação humana. Além da importância que têm no ciclo silvestre do T. cruzi, podem trazer a infecção para os ecótopos artificiais e, em determinadas instâncias, participar do ciclo domiciliário do parasita. Exemplos: Rhodnius neglectus, Triatoma vitticeps. Triatoma platensis e outras espécies pouco estudadas. 4 Triatomíneos que se criam indiferentemente em

Estudio seroepidemiológico y entomológico sobre la enfermedad de Chagas en un área infestada por Triatoma maculata (Erichson 1848 en el centro-occidente de Venezuela An entomological and seroepidemiological study of Chagas' disease in an area in central-western Venezuela infested with Triatoma maculata (Erichson 1848

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María Elena Rojas

2008-10-01

Full Text Available En el presente trabajo se realizó un estudio seroepidemiológico, entomológico y de factores de riesgo para la infestación de las viviendas en un área infestada por Triatoma maculata (Parroquia Xaguas, Municipio Urdaneta, Estado Lara, Venezuela. Se muestrearon 140 viviendas, 509 personas y 110 cánidos, a los cuales se les determinó anticuerpos séricos anti-Trypanosoma cruzi mediante ELISA y MABA, utilizando antígenos recombinantes. La infección por Tr. cruzi de los triatominos fue determinada por microscopía óptica y PCR. Los resultados mostraron una seroprevalencia en humanos de 1,57% y en cánidos de 6,36%. De los 545 triatominos capturados 97,98% fueron T. maculata, 1,65% Eratyrus mucronatus y 0,37% Panstrongylus geniculatus; con índices vectoriales de infección 0,36%, infestación 16,4%, colonización 39,1%, coinfestación 8,6% y dispersión 100%. La presencia de vectores en el domicilio y peridomicilio estuvo asociada a la presencia de gallinas, desorden en el peridomicilio, caprinos, gallineros y/o distribución del domicilio. Los resultados permiten concluir que T. maculata es el vector predominante en la región, con capacidad de infestar y colonizar el domicilio y estaría involucrado en la transmisión de la enfermedad de Chagas.This article presents a study on seroepidemiological, entomologic, and risk factors for domiciliary infestation in a circumscribed area infested with Triatoma maculata in Parroquia Xaguas, Urdaneta Municipality, Lara State, Venezuela. One hundred and forty households, 509 persons, and 110 dogs were sampled. Serum anti-Trypanosoma cruzi antibodies were determined by means of ELISA and MABA techniques using recombinant antigens. Tr. cruzi infection in the triatomines was determined by direct microscopy and PCR. According to the results, 1.57% of humans and 6.36% of dogs were positive for serum anti-Tr. cruzi antibodies. Triatomine species were: 97.98% T. maculata, 1.65% Eratyrus mucronatus, and 0

New structures for goat corrals to control peridomestic populations of Triatoma infestans (Hemiptera: Reduviidae in the Gran Chaco of Argentina

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David Eladio Gorla

2013-05-01

Full Text Available Goat production is an important economic activity for rural communities in the Gran Chaco of Argentina. Goat corrals are important for the survival of peridomestic populations of Triatoma infestans. This study evaluated the impact of modifying the traditional structure of goat corrals on T. infestans populations and goat productivity in the region of Los Llanos (La Rioja. Thirty-nine experimental corrals were constructed and 57 traditional corrals were used as controls. We evaluated the infestations of the control and experimental corrals for five years following construction of the structures. The results showed that the new structures did not prevent the colonization, although it enhanced the detection of infestation at low densities of T. infestans. No significant difference was found in T. infestans population abundance between control and experimental corrals, probably because of the different detectability in the two types of structures, especially among the small nymphs. Although goat productivity average was higher in experimental than in control corrals, no significant difference was found because of high variability. The new structures can be used as a complement to promote the development of rural communities. Acceptability and adoption of the new corrals by the owners was high, as the enclosures offered better protection for the goats, increased growth of kids and facilitated herd handling.

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.

The opossum Didelphis virginiana as a synanthropic reservoir of Trypanosoma cruzi in Dzidzilché, Yucatán, México.

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Ruiz-Pina, Hugo A; Cruz-Reyes, Alejandro

2002-07-01

In México, the role of mammals in the transmission cycle of Trypanosoma cruzi is poorly known. In the State of Yucatán, an endemic area of Chagas disease, both Didelphis virginiana and D. marsupialis occur sympatrically. However, until now, only the former species had been found infected with T. cruzi. To evaluate the role of D. virginiana in a peridomestic transmission, nine periods of capture-recapture were performed around the village of Dzidzilché, Yucatán. The sex, age, reproductive status, location, and presence of infection with T. cruzi were recorded for each opossum. The chromosome morphology was used to identify the opossum species. T. cruzi was identified by the presence of pseudocysts of amastigotes in cardiac muscle fibers of Balb/c mice inoculated with strains isolated from opossums. However, xenodiagnosis was the best diagnostic method. Triatoma dimidiata, the vector, were collected in and around the opossums' nests, and human dwellings; and were checked for T. cruzi. From 102 blood samples of D. virginiana examined 55 (53.9%) were positive to T. cruzi, the only two D. marsupialis captured were negative. Significant differences were found between infection, and both sex and reproductive condition. Eight out of 14 triatomines collected in peridomestic nests (57.1%), and 32 of 197 captured inside houses (16.3%) were found infected, suggesting a peridomestic transmission. The statistically high abundance of infected opossums and triatomines during the dry season (March to May) suggested the existence of a seasonality in the peridomestic transmission of T. cruzi in Dzidzilché.

The opossum Didelphis virginiana as a synanthropic reservoir of Trypanosoma cruzi in Dzidzilché, Yucatán, México

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Hugo A Ruiz-Piña

2002-07-01

Full Text Available In México, the role of mammals in the transmission cycle of Trypanosoma cruzi is poorly known. In the State of Yucatán, an endemic area of Chagas disease, both Didelphis virginiana and D. marsupialis occur sympatrically. However, until now, only the former species had been found infected with T. cruzi. To evaluate the role of D. virginiana in a peridomestic transmission, nine periods of capture-recapture were performed around the village of Dzidzilché, Yucatán. The sex, age, reproductive status, location, and presence of infection with T. cruzi were recorded for each opossum. The chromosome morphology was used to identify the opossum species. T. cruzi was identified by the presence of pseudocysts of amastigotes in cardiac muscle fibers of Balb/c mice inoculated with strains isolated from opossums. However, xenodiagnosis was the best diagnostic method. Triatoma dimidiata, the vector, were collected in and around the opossums' nests, and human dwellings; and were checked for T. cruzi. From 102 blood samples of D. virginiana examined 55 (53.9% were positive to T. cruzi, the only two D. marsupialis captured were negative. Significant differences were found between infection, and both sex and reproductive condition. Eight out of 14 triatomines collected in peridomestic nests (57.1%, and 32 of 197 captured inside houses (16.3% were found infected, suggesting a peridomestic transmission. The statistically high abundance of infected opossums and triatomines during the dry season (March to May suggested the existence of a seasonality in the peridomestic transmission of T. cruzi in Dzidzilché.

Influência de hábitos antrópicos na dispersão de Triatoma pseudomaculata Corrêa & Espínola, 1964, através de Mimosa tenuiflora (Willdenow (Mimosaceae no Estado do Ceará, Brasil

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Freitas Simone Patrícia Carneiro

2004-01-01

Full Text Available Triatoma pseudomaculata foram capturados em entrecascas de Mimosa tenuiflora (jurema-preta em ecótopo silvestre de sete municípios do Estado do Ceará. Esta planta apresenta alta taxa de cobertura geográfica nas áreas de caatingas, sendo freqüentemente utilizada pela população rural. A presença de triatomíneos no peridomicílio, na região do Cariri, pode estar associada ao uso pela população da madeira de M. tenuiflora, quando trazida do ambiente silvestre, repleta de triatomíneos, facilitando conseqüentemente sua mobilização e dispersão.

Susceptibility to deltamethrin of wild and domestic populations of Triatoma infestans of the Gran Chaco and the Inter-Andean Valleys of Bolivia.

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Gomez, Marinely Bustamante; D'Avila, Grasielle Caldas Pessoa; Orellana, Ana Lineth Garcia; Cortez, Mirko Rojas; Rosa, Aline Cristine Luiz; Noireau, François; Diotaiuti, Liléia Gonçalves

2014-11-14

The persistence of Triatoma infestans and the continuous transmission of Trypanosoma cruzi in the Inter-Andean Valleys and in the Gran Chaco of Bolivia are of great significance. Coincidentally, it is in these regions the reach of the vector control strategies is limited, and reports of T. infestans resistance to insecticides, including in wild populations, have been issued. This study aims to characterize the susceptibility to deltamethrin of wild and domestic populations of T. infestans from Bolivia, in order to better understand the extent of this relevant problem. Susceptibility to deltamethrin was assessed in nine, wild and domestic, populations of T. infestans from the Gran Chaco and the Inter-Andean Valleys of Bolivia. Serial dilutions of deltamethrin in acetone (0.2 μL) were topically applied in first instar nymphs (F1, five days old, fasting, weight 1.2 ± 0.2 mg). Dose response results were analyzed with PROBIT version 2, determining the lethal doses, slope and resistance ratios (RR). Qualitative tests were also performed. Three wild T. infestans dark morph samples of Chaco from the Santa Cruz Department were susceptible to deltamethrin with RR50 of Bolivia are less susceptible.

Triatoma infestans Calreticulin: Gene Cloning and Expression of a Main Domain That Interacts with the Host Complement System.

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Weinberger, Katherine; Collazo, Norberto; Aguillón, Juan Carlos; Molina, María Carmen; Rosas, Carlos; Peña, Jaime; Pizarro, Javier; Maldonado, Ismael; Cattan, Pedro E; Apt, Werner; Ferreira, Arturo

2017-02-08

Triatoma infestans is an important hematophagous vector of Chagas disease, a neglected chronic illness affecting approximately 6 million people in Latin America. Hematophagous insects possess several molecules in their saliva that counteract host defensive responses. Calreticulin (CRT), a multifunctional protein secreted in saliva, contributes to the feeding process in some insects. Human CRT (HuCRT) and Trypanosoma cruzi CRT (TcCRT) inhibit the classical pathway of complement activation, mainly by interacting through their central S domain with complement component C1. In previous studies, we have detected CRT in salivary gland extracts from T. infestans We have called this molecule TiCRT. Given that the S domain is responsible for C1 binding, we have tested its role in the classical pathway of complement activation in vertebrate blood. We have cloned and characterized the complete nucleotide sequence of CRT from T. infestans , and expressed its S domain. As expected, this S domain binds to human C1 and, as a consequence, it inhibits the classical pathway of complement, at its earliest stage of activation, namely the generation of C4b. Possibly, the presence of TiCRT in the salivary gland represents an evolutionary adaptation in hematophagous insects to control a potential activation of complement proteins, present in the massive blood meal that they ingest, with deleterious consequences at least on the anterior digestive tract of these insects. © The American Society of Tropical Medicine and Hygiene.

Toxicity, repellency and flushing out in Triatoma infestans (Hemiptera: Reduviidae exposed to the repellents DEET and IR3535

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Mercedes M.N. Reynoso

2017-05-01

Full Text Available DEET and IR3535 are insect repellents present worldwide in commercial products; their efficacy has been mainly evaluated in mosquitoes. This study compares the toxicological effects and the behavioral responses induced by both repellents on the blood-sucking bug Triatoma infestans Klug (Hemiptera: Reduviidae, one of the main vectors of Chagas disease. When applied topically, the Median Lethal Dose (72 h for DEET was 220.8 µg/insect. Using IR3535, topical application of 500 µg/insect killed no nymphs. The minimum concentration that produced repellency was the same for both compounds: 1,15 µg/cm2. The effect of a mixture DEET:IR3535 1:1 was similar to that of their pure components. Flushing out was assessed in a chamber with a shelter containing groups of ten nymphs. The repellents were aerosolized on the shelter and the number of insects leaving it was recorded for 60 min. During that time, 0.006 g/m3 of the positive control tetramethrin flushed out 76.7% of the nymphs, while 1.76 g/m3 of DEET or IR3535 flushed out 30 and 0%, respectively. The concentrations required for both compounds to produce toxicity or flushing out are too high to have any practical applications. However, they showed a promising repellency. Additional research should be done to evaluate their possible use for personal protection against T. infestans bites.

Analysing deltamethrin susceptibility and pyrethroid esterase activity variations in sylvatic and domestic Triatoma infestans at the embryonic stage

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Pablo Luis Santo-Orihuela

2013-12-01

Full Text Available The aim of the present work was to study the deltamethrin susceptibility of eggs from Triatoma infestans populations and the contribution of pyrethroid esterases to deltamethrin degradation. Insects were collected from sylvatic areas, including Veinte de Octubre and Kirus-Mayu (Bolivia and from domiciliary areas, including El Palmar (Bolivia and La Pista (Argentina. Deltamethrin susceptibility was determined by dose-response bioassays. Serial dilutions of deltamethrin (0.0005-1 mg/mL were topically applied to 12-day-old eggs. Samples from El Palmar had the highest lethal dose ratio (LDR value (44.90 compared to the susceptible reference strain (NFS, whereas the Veinte de Octubre samples had the lowest value (0.50. Pyrethroid esterases were evaluated using 7-coumaryl permethrate (7-CP on individually homogenised eggs from each population and from NFS. The El Palmar and La Pista samples contained 40.11 and 36.64 pmol/min/mg protein, respectively, and these values were statistically similar to NFS (34.92 pmol/min/mg protein and different from Kirus-Mayu and Veinte de Octubre (27.49 and 22.69 pmol/min/mg protein, respectively. The toxicological data indicate that the domestic populations were resistant to deltamethrin, but no statistical contribution of 7-CP esterases was observed. The sylvatic populations had similar LDR values to NFS, but lower 7-CP esterase activities. Moreover, this is the first study of the pyrethroid esterases on T. infestans eggs employing a specific substrate (7-CP.

Aspectos ecológicos da tripanossomíase americana: XVII - Desenvolvimento da domiciliação triatomínea regional, em centro de endemismo de Triatoma sordida Ecological aspects of South American trypanosomiasis: XVII - The domiciliation development of local triatominae populations in the Triatoma sordida endemic center

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Oswaldo Paulo Forattini

1983-06-01

Full Text Available São apresentados os resultados obtidos mediante as observações sobre o processo de domiciliação triatomínea, após a desinsetização domiciliar, e levadas a efeito no período de janeiro de 1975 a janeiro de 1979. A região estudada inclui-se no domínio paisagístico dos cerrados do Brasil Central, considerado como centro de dispersão de Triatoma sordida. A domiciliação local, inicialmente encontrada, implicou a participação dessa espécie e de Triatoma infestans. Após a realização do expurgo, as pesquisas de vigilância trimestrais e os levantamentos finais evidenciaram a ocorrência de novo processo de domiciliação de triatomíneos, de decurso lento, e resultando em coeficientes de positividade de edifícios acentuadamente inferiores aos registrados por ocasião do levantamento inicial, durante todo o período de observação. Após o expurgo, o valor geral do coeficiente de edifícios (casas e anexos positivos variou do valor mínimo de 1,9 ao máximo de 5,7%, enquanto foi de 40,4% o observado quando do levantamento inicial. Essa situação perdurou pelo tempo mínimo de três anos e meio, o que permite recomendar que a vigilância e a possível aplicação do expurgo seletivo, subseqüentes à desinsetização geral, sejam iniciadas a partir de decorrido tal prazo. Nesse ínterim, recomenda-se a motivação dos habitantes locais, no sentido de obter-lhes a colaboração para a denúncia de novos focos intradomiciliares. Na transferência da infecção tripanossômica para o ambiente domiciliar evidenciou-se papel importante desempenhado por vertebrados domiciliados ou em domiciliação, em especial modo ratos (Rattus e gambás (Didelphis, de hábitos ubiquistas. No processo de evolução da nova domiciliação triatomínea, coube papel preponderante a T. sordida mediante a ocupação inicial do peridomicílio. O reaparecimento de T. infestans deveu-se principalmente à influência da atividade humana, em especial modo, a

Soroprevalência de infecção chagásica em área de Triatoma infestans após medidas de controle Seroprevalence of Chagas disease in an area of Triatoma infestans after vector control measures

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Maria Esther Carvalho

2000-02-01

Full Text Available INTRODUÇÃO: Como parte de projeto que busca resgatar informações sobre sorologia da infecção chagásica no Estado de São Paulo durante a vigência das atividades oficiais de controle de vetores, foram selecionados dados relativos ao município de Taquarituba, região de Sorocaba, de importante passado chagásico. A despeito da campanha de combate instituída na década de 50, ainda persistiam aí populações de triatomíneos vetores intradomiciliares na década de 70. MÉTODOS: De amostras das populações de cinco localidades do Município de Taquarituba, Estado de São Paulo, foram analisados os dados de idade, sexo, tempo de moradia na casa que ocupavam e naturalidade. A possível relação entre idade e soropositividade foi investigada utilizando-se o cálculo de probitos. De 1974 e 1976, a prevalência da infecção chagásica foi estimada por meio de reação de imunofluorescência indireta (RIFI para a detecção de anticorpos anti-Trypanosoma cruzi. RESULTADOS: A proporção total de soropositivos foi de 13,6% (n = 2.784, sem diferença significativa entre os sexos (p = 0,538. Os naturais de Taquarituba contribuíram com 62,9% das amostras examinadas e 62,4% dos soropositivos (n = 380. Ausente em crianças de menos de 6 anos, a soropositividade aumentou de 2,7% no grupo etário de 6 a 9 anos para 30,3% no de 30 a 39 anos. Dentro desse intervalo encontrou-se, por meio do cálculo de probitos, associação positiva entre idade e soropositividade. CONCLUSÕES: Os resultados das provas sorológicas sugeriram haver associação entre as medidas contra Triatoma infestans e o declínio da transmissão da doença de Chagas durante os anos 60, seguido de ulterior controle. Sugere-se a realização de pesquisa para investigar a ocorrência de infecção congênita em população feminina com mais de 14 anos, sorologicamente positivas.INTRODUCTION: The study is part of a project intended to retrieve information about the serology of the

Fonte alimentar e potencial vetorial de Triatoma vitticeps (Stal, 1859 com relação à doença de Chagas humana no estado do Espírito Santo, Brasil (Hemiptera, Reduviidae Feeding and vectorial capacity of Triatoma vitticeps (Stal, 1859 in relation with human chagas' disease in Espírito Santo State, Brazil

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João Carlos Pinto Dias

1989-01-01

Full Text Available In paralel with several other epidemiologic and entomologic data of 19 Municipalities of Espírito Santo State, Brazil, the feeding pattern of 222 Triatoma vitticeps is studied through precipitin tests. Very high levels of natural infection with Trypanosoma cruzi are observed in adult insects, in contrast with the abscence or minimum degrees of infection among nymphs and human individuals. The precipitin tests showed the contact of the insects with multiple blood sources, chiefly human and birds, followed by rodents and marsupials. The data suggest that T. vitticeps in spite of being highly antropophilic, become infected by T. cruzi in sylvatic ambient and occasionally invade houses. The species doesn't seem to be - at least until now - a good vector in the domestic cycle of Chagas' disease. Several factors seem to be involved in this conclusion, mainly the low density of the insect in the houses, its hardness to coloniza them, its slowness concerning to suction and defecation and possibly its low susceptibility to different T. cruzi strains.

Feeding and defecation behavior of Triatoma rubida (Uhler, 1894) (Hemiptera: Reduviidae) under laboratory conditions, and its potential role as a vector of Chagas disease in Arizona, USA.

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Reisenman, Carolina E; Gregory, Teresa; Guerenstein, Pablo G; Hildebrand, John G

2011-10-01

Chagas disease is caused by the parasite Trypanosoma cruzi, which is transmitted to humans by blood-sucking triatomine insects. This disease is endemic throughout Mexico and Central and South America, but only a few autochthonous cases have been reported in the United States, despite the fact that infected insects readily invade houses and feed on humans. Competent vectors defecate during or shortly after feeding so that infective feces contact the host. We thus studied the feeding and defecation behaviors of the prevalent species in southern Arizona, Triatoma rubida. We found that whereas defecation during feeding was frequent in females (93%), it was very rare in immature stages (3%), and absent in males. Furthermore, more than half of the immature insects that exhibited multiple feeding bouts (62%) defecated during interruptions of feeding, i.e., while likely on or near the host. These results indicate that T. rubida potentially could transmit T. cruzi to humans.

Southern Cone Initiative for the elimination of domestic populations of Triatoma infestans and the interruption of transfusion Chagas disease: historical aspects, present situation, and perspectives

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João Carlos Pinto Dias

2007-10-01

Full Text Available Created in 1991 by the governments of Argentina, Bolivia, Brazil, Chile, Paraguay, and Uruguay, the Southern Cone Initiative (SCI has been extremely important for Chagas disease control in this region. Its basic objective was to reach the interruption of this disease, chiefly by means of the elimination of the principal vector Triatoma infestans and by the selection of safe donors in the regional blood banks. After a summarized historic of SCI, the text shows the advance of technical and operative activities, emphasizing some factors for the initiative success, as well as some difficulties and constraints. The future of SCI will depend of the continuity of the actions and of political priority. Scientific community has been highly responsible for this initiative and its maintenance. At the side of this, national and international efforts must be involved and reinforced to assure the accomplishment of the final targets of SCI. Very specially, the Pan American Health Organization has cooperated with the Initiative in all its moments and activities,being the most important catalytic and technical factor for SCI success.

Changes related to gender, geographic population and habitat in the antennal phenotype of Triatoma patagonica Del Ponte, 1929 (Hemiptera: Reduviidae).

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Rodríguez, Claudia S; Crocco, Liliana; Altamirano, Alejandra; Catalá, Silvia

2013-02-01

Triatomines undergo morphological changes as an adaptive response to different habitats (wild, peridomestic, domestic, laboratory). The characterization of the antennal phenotype provides information on intraspecific variation caused by geographical origin and/or habitat. Triatoma patagonica Del Ponte, 1929 is known to occur in peridomiciles of rural areas in Argentina, where it also invades non-colonized dwellings. Here we describe and compare the antennal phenotype of T. patagonica in populations of different geographic origin, and explore possible modifications induced by laboratory rearing with the aim of investigating the range of phenotypic variation of the species for the first time. Sixty antennas of adult males and females of T. patagonica belonging to two peridomiciliary populations of different geographical origin were analyzed. Four types of sensilla were observed in three antennal segments, showing sexual dimorphism in the species. The multivariate analysis separated the populations of similar habitat (peridomicile) but different geographical origin, without showing differences between the peridomiciliary and laboratory populations of the same geographical origin. These results suggest phenotypic plasticity in T. patagonica, which would allow the species to adapt to a wide range of habitats without having a close association with a given host and its environment. The range of antennal phenotypic variation of T. patagonica would also be an indicator of its current stage of adaptation to the human environment. Copyright © 2012 Elsevier B.V. All rights reserved.

Is imidacloprid an effective alternative for controlling pyrethroid-resistant populations of Triatoma infestans (Hemiptera: Reduviidae in the Gran Chaco ecoregion?

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Guillermo Carvajal

2014-09-01

Full Text Available The prevention of Chagas disease is based primarily on the chemical control of Triatoma infestans (Klug using pyrethroid insecticides. However, high resistance levels, correlated with control failures, have been detected in Argentina and Bolivia. A previous study at our laboratory found that imidacloprid could serve as an alternative to pyrethroid insecticides. We studied the delayed toxicity of imidacloprid and the influence of the blood feeding condition of the insect on the toxicity of this insecticide; we also studied the effectiveness of various commercial imidacloprid formulations against a pyrethroid-resistant T. infestans population from the Gran Chaco ecoregion. Variations in the toxic effects of imidacloprid were not observed up to 72 h after exposure and were not found to depend on the blood feeding condition of susceptible and resistant individuals. Of the three different studied formulations of imidacloprid on glass and filter paper, only the spot-on formulation was effective. This formulation was applied to pigeons at doses of 1, 5, 20 and 40 mg/bird. The nymphs that fed on pigeons treated with 20 mg or 40 mg of the formulation showed a higher mortality rate than the control group one day and seven days post-treatment (p < 0.01. A spot-on formulation of imidacloprid was effective against pyrethroid-resistant T. infestans populations at the laboratory level.

Detección de triatominos (Hemiptera: Reduviidae en ambientes domésticos y extradomésticos. Corrientes, Argentina Detection of triatomines (Hemiptera: Reduviidae in domiciliary and extra-domiciliary ecotopes. Corrientes, Argentina

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Miryam Pieri Damborsky

2001-08-01

Full Text Available Esta investigación tiene como objetivo identificar los triatominos que predominan en ambientes domésticos y extradomésticos de diferentes departamentos de la Provincia de Corrientes mediante muestreos llevados a cabo desde 1985 hasta 1995. En los ecótopos domiciliarios se detectaron Triatoma infestans (Klug, 1834, Triatoma sordida (Stål, 1859, Panstrongylus geniculatus (Latreille, 1811 y Panstrongylus megistus (Burmeister, 1835. T. infestans y T. sordida se hallaron también en ambientes peridomésticos. Triatoma platensis (Neiva, 1913, Psammolestes coreodes (Bergroth, 1911, T. sordida y Triatoma rubrovaria (Blanchard, 1843 se colectaron en biótopos silvestres. En los domicilios, se confirmó el predominio de T. infestans. Esta especie fue la única parasitada por tripanosomas cruziformes. Si bien T. sordida fue más frecuente en los ecótopos extradomésticos, se demostró su tendencia a colonizar los ambientes domésticos.In order to identify intra- and extra-domiciliary triatomines, a study in different counties of Corrientes Province, Argentina, was conducted from 1985 to 1995. Triatoma infestans (Klug, 1834, Triatoma sordida (Stål, 1859, Panstrongylus geniculatus (Latreille, 1811, and Panstrongylus megistus (Burmeister, 1835 were detected in domestic ecotopes. T. infestans and T. sordida were also found in the peridomicile. Triatoma platensis (Neiva, 1913, Psammolestes coreodes (Bergroth, 1911, T. sordida, and Triatoma rubrovaria (Blanchard, 1843 were collected in sylvatic biotopes. T. infestans was confirmed as the predominant species in the domestic environment and was the only species infected with Trypanosoma cruzi-like parasites. T. sordida was most frequent in extra-domiciliary ecotopes, but could be considered capable of colonizing human dwellings.

Effects of Non-Susceptible Hosts on the Infection with Trypanosoma cruzi of the Vector Triatoma infestans: an Experimental Model

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Vázquez Diego P

1999-01-01

Full Text Available We tested experimentally the effects of the presence of non-susceptible hosts on the infection with Trypanosoma cruzi of the vector Triatoma infestans. The experiment consisted in two treatments: with chickens, including two chickens (non-susceptible hosts and two infected guinea pigs (susceptible hosts, and without chickens, including only two infected guinea pigs. The hosts were held unrestrained in individual metal cages inside a closed tulle chamber. A total of 200 uninfected T. infestans third instar nymphs were liberated in each replica, collected on day 14, and examined for infection and blood meal sources on day 32-36. The additional presence of chickens relative to infected guinea pigs: (a significantly modified the spatial distribution of bugs; (b increased significantly the likelihoods of having a detectable blood meal on any host and molting to the next instar; (c did not affect the bugs' probability of death by predation; and (d decreased significantly the overall percentage of T. infestans infected with T. cruzi. The bugs collected from inside or close to the guinea pigs' cages showed a higher infection rate (71-88% than those collected from the chickens' cages (22-32%. Mixed blood meals on chickens and guinea pigs were detected in 12-21% of bugs. Although the presence of chickens would decrease the overall percentage of infected bugs in short term experiments, the high rate of host change of T. infestans would make this difference fade out if longer exposure times had been provided.

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

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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.

The epidemiologic importance of Triatoma brasiliensis as a Chagas disease vector in Brazil: a revision of domiciliary captures during 1993-1999

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Costa Jane

2003-01-01

Full Text Available To clarify the epidemiologic importance of Triatoma brasiliensis, the most important Chagas disease vector in the Northeastern of Brazil, capture data related to this species, its distribution, capture index, and percentages of natural infection by Trypanosoma cruzi were examined in 12 different Brazilian states. The Brazilian National Health Foundation collected these data from 1993 to 1999, a period during which a total of 1,591,280 triatomines (21 species were captured in domiciles within the geographic range of T. brasiliensis. Of this total, 422,965 (26.6% were T. brasiliensis, 99.8% of which were collected in six states, and 54% in only one state (Ceará. The percentage of bugs infected with T. cruzi varied significantly among states, ranging from 0% (Goiás, Maranhão, Sergipe, and Tocantins to more than 3% (Alagoas, Minas Gerais, and Rio Grande do Norte with an average of 1.3%. This latter value represents a dramatic reduction in the natural infection percentages since 1983 (6.7% suggesting that, despite the impossibility of eradicating this native species, the control measures have significantly reduced the risk of transmission. However, the wide geographic distribution of T. brasiliensis, its high incidence observed in some states, and its variable percentages of natural infection by T. cruzi indicate the need for sustained entomological surveillance and continuous control measures against this vector.

Distribution of Pyrethroid Resistant Populations of Triatoma infestans in the Southern Cone of South America.

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Marinely Bustamante Gomez

2016-03-01

Full Text Available A number of studies published during the last 15 years showed the occurrence of insecticide resistance in Triatoma infestans populations. The different toxicological profiles and mechanisms of resistance to insecticides is due to a genetic base and environmental factors, being the insecticide selective pressure the best studied among the last factors. The studies on insecticide resistance on T. infestans did not consider the effect of environmental factors that may influence the distribution of resistance to pyrethroid insecticides. To fill this knowledge gap, the present study aims at studying the association between the spatial distribution of pyrethroid resistant populations of T. infestans and environmental variables.A total of 24 articles reporting on studies that evaluated the susceptibility to pyrethroids of 222 field-collected T. infestans populations were compiled. The relationship between resistance occurrence (according to different criteria with environmental variables was studied using a generalized linear model. The lethal dose that kills 50% of the evaluated population (LD50 showed a strong linear relationship with the corresponding resistance ratio (RR50. The statistical descriptive analysis of showed that the frequency distribution of the Log (LD50 is bimodal, suggesting the existence of two statistical groups. A significant model including 5 environmental variables shows the geographic distribution of high and low LD50 groups with a particular concentration of the highest LD50 populations over the region identified as the putative center of dispersion of T. infestans.The occurrence of these two groups concentrated over a particular region that coincides with the area where populations of the intermediate cytogenetic group were found might reflect the spatial heterogeneity of the genetic variability of T. infestans, that seems to be the cause of the insecticide resistance in the area, even on sylvatic populations of T. infestans

Putative panmixia in restricted populations of Trypanosoma cruzi isolated from wild Triatoma infestans in Bolivia.

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Christian Barnabe

Full Text Available Trypanosoma cruzi, the causative agent of Chagas disease, is subdivided into six discrete typing units (DTUs; TcI-TcVI of which TcI is ubiquitous and genetically highly variable. While clonality is the dominant mode of propagation, recombinant events play a significant evolutive role. Recently, foci of wild Triatoma infestans have been described in Bolivia, mainly infected by TcI. Hence, for the first time, we evaluated the level of genetic exchange within TcI natural potentially panmictic populations (single DTU, host, area and sampling time. Seventy-nine TcI stocks from wild T. infestans, belonging to six populations were characterized at eight microsatellite loci. For each population, Hardy-Weinberg equilibrium (HWE, linkage disequilibrium (LD, and presence of repeated multilocus genotypes (MLG were analyzed by using a total of seven statistics, to test the null hypothesis of panmixia (H0. For three populations, none of the seven statistics allowed to rejecting H0; for another one the low size did not allow us to conclude, and for the two others the tests have given contradictory results. Interestingly, apparent panmixia was only observed in very restricted areas, and was not observed when grouping populations distant of only two kilometers or more. Nevertheless it is worth stressing that for the statistic tests of "HWE", in order to minimize the type I error (i. e. incorrect rejection of a true H0, we used the Bonferroni correction (BC known to considerably increase the type II error ( i. e. failure to reject a false H0. For the other tests (LD and MLG, we did not use BC and the risk of type II error in these cases was acceptable. Thus, these results should be considered as a good indicator of the existence of panmixia in wild environment but this must be confirmed on larger samples to reduce the risk of type II error.

Putative Panmixia in Restricted Populations of Trypanosoma cruzi Isolated from Wild Triatoma infestans in Bolivia

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Barnabe, Christian; Buitrago, Rosio; Bremond, Philippe; Aliaga, Claudia; Salas, Renata; Vidaurre, Pablo; Herrera, Claudia; Cerqueira, Frédérique; Bosseno, Marie-France; Waleckx, Etienne; Breniere, Simone Frédérique

2013-01-01

Trypanosoma cruzi, the causative agent of Chagas disease, is subdivided into six discrete typing units (DTUs; TcI–TcVI) of which TcI is ubiquitous and genetically highly variable. While clonality is the dominant mode of propagation, recombinant events play a significant evolutive role. Recently, foci of wild Triatoma infestans have been described in Bolivia, mainly infected by TcI. Hence, for the first time, we evaluated the level of genetic exchange within TcI natural potentially panmictic populations (single DTU, host, area and sampling time). Seventy-nine TcI stocks from wild T. infestans, belonging to six populations were characterized at eight microsatellite loci. For each population, Hardy-Weinberg equilibrium (HWE), linkage disequilibrium (LD), and presence of repeated multilocus genotypes (MLG) were analyzed by using a total of seven statistics, to test the null hypothesis of panmixia (H0). For three populations, none of the seven statistics allowed to rejecting H0; for another one the low size did not allow us to conclude, and for the two others the tests have given contradictory results. Interestingly, apparent panmixia was only observed in very restricted areas, and was not observed when grouping populations distant of only two kilometers or more. Nevertheless it is worth stressing that for the statistic tests of "HWE", in order to minimize the type I error (i. e. incorrect rejection of a true H0), we used the Bonferroni correction (BC) known to considerably increase the type II error ( i. e. failure to reject a false H0). For the other tests (LD and MLG), we did not use BC and the risk of type II error in these cases was acceptable. Thus, these results should be considered as a good indicator of the existence of panmixia in wild environment but this must be confirmed on larger samples to reduce the risk of type II error. PMID:24312410

Insects found in birds' nests from Argentina. Pseudoseisura lophotes Reichenbach, 1853 and Anumbius annumbi (Vieillot, 1817) (Aves: Furnariidae), hosts of Triatoma platensis Neiva, 1913 (Hemiptera: Reduviidae: Triatominae).

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Paola, Turienzo

2014-02-24

The insect fauna of the nests of Pseudoseisura lophotes (Reichenbach, 1853) (Aves: Furnariidae) from Argentina was investigated. A total of 110 species (68 identified to species, 22 identified to genus, 20 identified to family) in 40 families of 10 orders of insects was found in these nests. Triatoma platensis Neiva, 1913 (Hemiptera: Reduviidae) was found again in nests of P. lophotes, corroborating after 73 years the first observations made by Mazza in 1936. The occurrence of the insects in nests of P. lophotes is compared with the previously known insect fauna in nests of A. annumbi, Furnarius rufus (Furnariidae), and Myiopsitta monachus (Psittacidae). The insect fauna in additional nests of Anumbius annumbi from the same and/or different localities is given, and used in comparisons. The first occurrence of Cuterebridae (Diptera) in birds' nests, their pupae as the overwintering stage, and the second simultaneous infestation by two species of Philornis (Diptera: Muscidae) on the same nestlings are presented. Other simultaneous infestations of different hematophagous arthropods (Hemiptera: Cimidae; Reduviidae: Triatominae, and Acari: Argasidae) are remarked and discussed.

Life cycle and vectorial competence of Triatoma williami (Galvão, Souza e Lima, 1965) under the influence of different blood meal sources.

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Lunardi, Rosaline Rocha; Gomes, Letícia Pinho; Peres Câmara, Thaís; Arrais-Silva, Wagner Welber

2015-09-01

Triatoma williami is naturally infected by Trypanosoma cruzi, the ethiological agent of Chagas disease, the most significant cause of morbidity and mortality in South and Central America.The possibility of domiciliation of T. williami increases the risk of human T. cruzi vetorial transmission. Despite this, there is a lack of data demonstrating the bionomic aspects, the vectorial competence or the natural ecotope and the wild hosts of T. williami. This study describes for the first time the life cycle of T. williami under the influence of two blood meal sources and also evaluates the vectorial potential of the species. The development of two groups of hundred triatomines was followed over the nymphal stages and adulthood. Each group was exposed to a sole blood meal source, mammalian or bird. The average egg-to-adult development time in both groups was similar, except by shorter stages of N3 and N4 in triatomines fed on mammals. The group fed on birds needed more blood feedings to suffer the ecdysis and had higher cumulative mortality in the nymphal stages. Although the observed delay at defecation of adults after feeding, our results suggest that T. williami in the third and fifth nymphal stages may be good vectors. Copyright © 2015 Elsevier B.V. All rights reserved.

A Microsatellite-Based Analysis of House Infestation With Triatoma Infestans (Hemiptera: Reduviidae) After Insecticide Spraying in the Argentine Chaco.

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Piccinali, Romina V; Gaunt, Michael W; Gürtler, Ricardo E

2018-05-04

Prevention of vector-borne transmission of Chagas disease mainly relies on residual insecticide spraying. Despite significant success at a regional scale, house infestation with Triatoma infestans (Klug) (Hemiptera: Reduviidae) still persists in the Gran Chaco ecoregion. One key aspect is the identification of the sources of reinfestant triatomines. After detecting fine-scale genetic structure in two rural villages of Pampa del Indio, Argentine Chaco, we tested hypotheses on the putative origins of the triatomines collected at 4, 8, and 12 mo after insecticide house spraying. We genotyped 10 microsatellite loci in 262 baseline and 83 postspraying triatomines from different houses. Genetic variability was similar between baseline and postspraying populations, but 13 low-frequency alleles were not detected at postspraying. FSTs were not significant between insects collected before and after insecticide spraying at the same house in all but one case, and they clustered together in a neighbor-joining tree. A clustering algorithm detected seven genetic groups, four of them mainly composed of baseline and postspraying insects from the same house. Assignment tests suggested multiple putative sources (including the house of collection) for most postspraying insects but excluded a house located more than 9 km from the study area. The origin of three triatomines was attributed to immigration from other unaccounted sources. Our study is compatible with the hypothesis that house reinfestations in the Argentine Chaco are mostly related to residual foci (i.e., survival of insects within the same community), in agreement with field observations, spatial analysis, and morphometric studies previously published.

Domestic, peridomestic and wild hosts in the transmission of Trypanosoma cruzi in the Caatinga area colonised by Triatoma brasiliensis

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Claudia Mendonça Bezerra

2014-11-01

Full Text Available The role played by different mammal species in the maintenance of Trypanosoma cruzi is not constant and varies in time and place. This study aimed to characterise the importance of domestic, wild and peridomestic hosts in the transmission of T. cruzi in Tauá, state of Ceará, Caatinga area, Brazil, with an emphasis on those environments colonised by Triatoma brasiliensis. Direct parasitological examinations were performed on insects and mammals, serologic tests were performed on household and outdoor mammals and multiplex polymerase chain reaction was used on wild mammals. Cytochrome b was used as a food source for wild insects. The serum prevalence in dogs was 38% (20/53, while in pigs it was 6% (2/34. The percentages of the most abundantly infected wild animals were as follows: Thrichomys laurentius 74% (83/112 and Kerodon rupestris 10% (11/112. Of the 749 triatomines collected in the household research, 49.3% (369/749 were positive for T. brasiliensis, while 6.8% were infected with T. cruzi (25/369. In captured animals, T. brasiliensis shares a natural environment with T. laurentius, K. rupestris, Didelphis albiventris, Monodelphis domestica, Galea spixii, Wiedomys pyrrhorhinos, Conepatus semistriatus and Mus musculus. In animals identified via their food source, T. brasiliensis shares a natural environment with G. spixii, K. rupestris, Capra hircus, Gallus gallus, Tropidurus oreadicus and Tupinambis merianae. The high prevalence of T. cruzi in household and peridomiciliar animals reinforces the narrow relationship between the enzootic cycle and humans in environments with T. brasiliensis and characterises it as ubiquitous.

Host-seeking behavior and dispersal of Triatoma infestans, a vector of Chagas disease, under semi-field conditions.

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Ricardo Castillo-Neyra

2015-01-01

Full Text Available Chagas disease affects millions of people in Latin America. The control of this vector-borne disease focuses on halting transmission by reducing or eliminating insect vector populations. Most transmission of Trypanosoma cruzi, the causative agent of Chagas disease, involves insects living within or very close to households and feeding mostly on domestic animals. As animal hosts can be intermittently present it is important to understand how host availability can modify transmission risk to humans and to characterize the host-seeking dispersal of triatomine vectors on a very fine scale. We used a semi-field system with motion-detection cameras to characterize the dispersal of Triatoma infestans, and compare the behavior of vector populations in the constant presence of hosts (guinea pigs, and after the removal of the hosts. The emigration rate - net insect population decline in original refuge - following host removal was on average 19.7% of insects per 10 days compared to 10.2% in constant host populations (p = 0.029. However, dispersal of T. infestans occurred in both directions, towards and away from the initial location of the hosts. The majority of insects that moved towards the original location of guinea pigs remained there for 4 weeks. Oviposition and mortality were observed and analyzed in the context of insect dispersal, but only mortality was higher in the group where animal hosts were removed (p-value <0.01. We discuss different survival strategies associated with the observed behavior and its implications for vector control. Removing domestic animals in infested areas increases vector dispersal from the first day of host removal. The implications of these patterns of vector dispersal in a field setting are not yet known but could result in movement towards human rooms.

Estudios sobre Trypanosomiasis americana en el Perú. Observaciones en el departamento de Ica

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Víctor M Ayulo Robles

1946-01-01

Full Text Available Hemos comprobado la presencia de Triatomas en las ciudades de Ica y Nazca. Los Triatomas encontrados en esas localidades son de la especie del Triatoma Infestans. Las observaciones del contenido intestinal de los Triatomas capturados en ambas ciudades reveló que ellos no se encuentran infestados; lo que hace sospechar que estos insectos procedan de la Ciudad de Arequipa. Los exámenes de sangre en fresco, gota gruesa y frotis coloreados por el método de Giemsa en 174 personas y 32 animales, así como las pruebas de Desviación del Complemento (Reacción de GUERREIRO Y MACHADO e intradermo-reacción en las 174 personas, fueron negativas; lo que demuestra que actualmente no existe la Enfermedad de Chagas en el Departamento de Ica. Dada la presencia de Triatomas en Ica y Nazca y la existencia de la Enfermedad de Chagas en Vitor, Sihuas y Quishuarani del Departamento de Arequipa no se excluye la posibilidad de que posteriormente se haga presente la Trypanosomiasis americana, también, en esas zonas.

Quantum Distinction: Quantum Distinctiones!

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Zeps, Dainis

2009-01-01

10 pages; How many distinctions, in Latin, quantum distinctiones. We suggest approach of anthropic principle based on anthropic reference system which should be applied equally both in theoretical physics and in mathematics. We come to principle that within reference system of life subject of mathematics (that of thinking) should be equated with subject of physics (that of nature). For this reason we enter notions of series of distinctions, quantum distinction, and argue that quantum distinct...

The residual efficacy of a cypermethrin pour-on formulation applied on goats on the mortality and blood intake of Triatoma infestans

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Ivana Amelotti

2012-12-01

Full Text Available Triatoma infestans is the main vector of Trypanosoma cruzi, the aetiological agent of Chagas disease in the Gran Chaco region of South America. As a frequent blood meal source for triatomine bugs, domestic goats play a key role in the eco-epidemiology of Chagas disease. The aim of this study was to evaluate the mortality and blood intake of T. infestans fed on goats that had been treated with different doses of pour-on insecticide. Third-instar nymphs were fed on goats that had been treated with 0 cc, 5 cc, 10 cc or 15 cc of a pour-on formulation of cypermethrin. The exposure of T. infestans to animals treated at different post-application intervals revealed a residual activity of the insecticide. The mortality rate in the treated groups was higher than in the control groups until 30 days post-insecticide application (p = 0.03, except in the group treated with 5 cc, in which no mortality was detected after seven days of insecticide application. Rainfall affected the triatomicide effect, reducing the time of residual activity. The cypermethrin pour-on treatment decreased the blood intake of T. infestans. Thirty days after the cypermethrin application, nymph mortality was 16% (± 13 with both doses (10 cc and 15 cc. The 15 cc dose did not result in higher insect mortality or increased persistence compared to the 10 cc dose.

The role of the peridomiciliary area in the elimination of Triatoma infestans from rural Argentine communities

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Cecere María C.

1997-01-01

Full Text Available The purpose of this study was to identify the origin of Triatoma infestans reinfestation and study its dynamics following spraying with deltamethrin inside and around 94 houses in three rural communities in northwestern Argentina. The effectiveness of the spraying was evaluated immediately after the houses were sprayed and two months later. In addition, five residual peridomiciliary foci were found and sprayed, as well as three preexisting ones that had not been sprayed. To monitor reinfestation, biosensors were placed in the houses and each family was also asked to capture triatomines and keep them in plastic bags; in addition, triatomines were searched for in and around houses, using an aerosol that dislodged them from their hiding places. Selective sprayings were carried out only where a colony of T. infestans was found. During the 30 months of follow-up, the percentage of houses in which any T. infestans were captured varied between 3% and 9%. In six houses, T. infestans were captured during more than one evaluation. The number of peridomiciliary areas found to be infested (19 was double the number of infested houses (9. Colonies of T. infestans were found only in the peridomiciliary areas, where the number of T. infestans captured was six times higher than in the houses. Chickens were the host most frequently associated with peridomiciliary foci. This area was the origin and principal source of reinfestation. To reduce the speed of reinfestation and the frequency with which sprayings are needed, the following environmental and chemical control methods must be combined in the peridomiciliary area: reduce the number of hiding places of triatomines; restrict the raising of birds to structures that cannot be colonized by triatomines; apply an insecticide that is less likely to be degraded by exposure to the elements, or perform a second spraying 6 to 12 months after the first; and employ a device for early detection of the presence of T

The eco-epidemiology of Triatoma infestans in the temperate Monte Desert ecoregion of mid-western Argentina

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Ana Laura Carbajal-de-la-Fuente

Full Text Available BACKGROUND The eco-epidemiological status of Chagas disease in the Monte Desert ecoregion of western Argentina is largely unknown. We investigated the environmental and socio-demographic determinants of house infestation with Triatoma infestans, bug abundance, vector infection with Trypanosoma cruzi and host-feeding sources in a well-defined rural area of Lavalle Department in the Mendoza province. METHODS Technical personnel inspected 198 houses for evidence of infestation with T. infestans, and the 76 houses included in the current study were re-inspected. In parallel with the vector survey, an environmental and socio-demographic survey was also conducted. Univariate risk factor analysis for domiciliary infestation was carried out using Firth penalised logistic regression. We fitted generalised linear models for house infestation and bug abundance. Blood meals were tested with a direct ELISA assay, and T. cruzi infection was determined using a hot-start polymerase chain reaction (PCR targeting the kinetoplast minicircle (kDNA-PCR. FINDINGS The households studied included an aged population living in precarious houses whose main economic activities included goat husbandry. T. infestans was found in 21.2% of 198 houses and in 55.3% of the 76 re-inspected houses. Peridomestic habitats exhibited higher infestation rates and bug abundances than did domiciles, and goat corrals showed high levels of infestation. The main host-feeding sources were goats. Vector infection was present in 10.2% of domiciles and 3.2% of peridomiciles. Generalised linear models showed that peridomestic infestation was positively and significantly associated with the presence of mud walls and the abundance of chickens and goats, and bug abundance increased with the number of all hosts except rabbits. MAIN CONCLUSIONS We highlight the relative importance of specific peridomestic structures (i.e., goat corrals and chicken coops associated with construction materials and host

De novo transcriptome assembly for a non-model species, the blood-sucking bug Triatoma brasiliensis, a vector of Chagas disease.

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Marchant, A; Mougel, F; Almeida, C; Jacquin-Joly, E; Costa, J; Harry, M

2015-04-01

High throughput sequencing (HTS) provides new research opportunities for work on non-model organisms, such as differential expression studies between populations exposed to different environmental conditions. However, such transcriptomic studies first require the production of a reference assembly. The choice of sampling procedure, sequencing strategy and assembly workflow is crucial. To develop a reliable reference transcriptome for Triatoma brasiliensis, the major Chagas disease vector in Northeastern Brazil, different de novo assembly protocols were generated using various datasets and software. Both 454 and Illumina sequencing technologies were applied on RNA extracted from antennae and mouthparts from single or pooled individuals. The 454 library yielded 278 Mb. Fifteen Illumina libraries were constructed and yielded nearly 360 million RNA-seq single reads and 46 million RNA-seq paired-end reads for nearly 45 Gb. For the 454 reads, we used three assemblers, Newbler, CAP3 and/or MIRA and for the Illumina reads, the Trinity assembler. Ten assembly workflows were compared using these programs separately or in combination. To compare the assemblies obtained, quantitative and qualitative criteria were used, including contig length, N50, contig number and the percentage of chimeric contigs. Completeness of the assemblies was estimated using the CEGMA pipeline. The best assembly (57,657 contigs, completeness of 80 %, <1 % chimeric contigs) was a hybrid assembly leading to recommend the use of (1) a single individual with large representation of biological tissues, (2) merging both long reads and short paired-end Illumina reads, (3) several assemblers in order to combine the specific advantages of each.

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

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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.

Ecologia domestica de la tripanosomiasis americana: perfil alimentario del triatoma infestans en un area rural de la província de Santiago del Estero, Argentina

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Cristina Wisnivesky-Colli

1987-03-01

Full Text Available Se describen los resultados entomológicos de un estúdio sobre transmiswn del Tripanosoma cruzi realizado en un caserío rural de Argentina. Se determino la prevalencia de infección elperfil alimentario de los Triatoma infestans domiciliados, relacionándose su densidad con el tipo de vivienda. Seis de las 18 viviendas estudiadas eran nuevas o mejoradas y en 16 los habitantes aplicaban hexaclorociclohexano. La menor densidad de vinchucas correspondió a las casas higiénicas o mejoradas con tratamiento químico, Los ranchos tratados presentaron un número de insectos 10 veces menor que un rancho no tratado, indicando la efectividad del control autogestado. Se hallaron T. infestans en el 100% de los dormitorios pero en sólo el 53% de los localesperidomiciliarios. Un 39% de las vinchucas intradomiciliarias estaban infectadas. El 96% de los insectos de dormitorios se alimentaron sobre hombre, perro, polloygato, siendo el índice afinidad para el perro 13 veces superior al correspondiente al hombre. Se discute la importancia epidemiológica de la concentración de vectores dentro de los dormitorios y su asociación trófica con los perros convivientes, nsí como la necessidad de combinar la mejora de vivienda con educación sanitaria.

Controle do Triatoma sordida no peridomicílio rural do município de Porteirinha, Minas Gerais, Brasil Control of Triatoma sordida in the rural peridomestic environment of Porteirinha municipality, Minas Gerais, Brazil

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Liléia Diotaiuti

1998-01-01

Full Text Available O Triatoma sordida é uma espécie predominantemente peridomiciliar e, atualmente, a mais capturada no Brasil. Para melhor compreender a resposta deste triatomíneo às atividades de controle, uma pesquisa de infestação triatomínica foi realizada em outubro de 1993 em 12 localidades rurais do município de Porteirinha, MG, Brasil. Foram capturados 772 exemplares de T. sordida, dos quais 3,6% estavam infectados pelo Trypanosoma cruzi. Dentre as 406 unidades domiciliares pesquisadas, 34,9% estavam infestadas. Dos 695 ecótopos peridomiciliares estudados, 27,6% foram positivos para a presença de T. sordida. O estudo revelou um peridomicílio simples, com poucos ecótopos positivos por unidade domiciliar e baixa densidade triatomínica (colônias de no máximo cinco insetos. O estudo constatou uma associação entre presença de triatomíneos e ecótopos de madeira: 72,8% dos triatomíneos foram capturados neste tipo de ecótopo. Entre as unidades domiciliares positivas, 62,9% ficavam próximas do ambiente silvestre (12 a 299 m; 92,3% dos ecótopos infestados ficavam a menos de 20 m das casas. O censo de animais peridomiciliares revelou que as galinhas correspondiam a 82,7% dos animais. As unidades domiciliares infestadas foram imediatamente borrifadas com deltametrina (25 mg i.a./m². Novas pesquisas de infestação foram feitas 7 meses (pesquisa 2 e 1 ano (pesquisa 3 após a borrifação. Na pesquisa 2 o número de triatomíneos correspondeu a 52,5% da população original e, na pesquisa 3, a 79,1% da mesma. A redução do número de triatomíneos capturados na pesquisa 2 incidiu principalmente sobre as ninfas. A grande proporção de adultos capturados nessa ocasião confirma a existência de apenas um ciclo anual do T. sordida na região. Na pesquisa 3 o aumento do número de ninfas demonstrou crescimento desta população, utilizando-se da grande disponibilidade de galinhas para alimentação. Apesar das dificuldades de borrifação e da

Estudos anatômicos e histológicos sôbre a subfamília Triatominae (Heteroptera, Reduviidae: V parte: anatomia do testículo e espermiocitogênese do Triatoma infestans

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Rudolf Barth

1956-06-01

Full Text Available Neste trabalho, faz-se o estudo das estruturas anatômica e histológica do testículo de Triatoma infestans. Da espermiogênese, descrevem-se apenas as fases que medeiam entre a formação dos espermiogônios e a dos espermídeos (espermiocitogênese. A espermiohistogênese bem como as anatomias do vas deferens e das glândulas anexas serão tratados na segunda parte dêste trabalho, já em preparo. O testículo de Triatoma infestans possui 7 folículos dos quais cada um se abre num vas efferens próprio, curto, desembocando êstes num único vas deferens geral. Na zona de transição entre vas efferens e vas deferens, encontra-se sempre um conjunto de massas tissulares que se estão necrosando em virtude da decomposição das paredes dos cistos. Em conseqüência, os feixes de espérmios são libertados e passam através do vas efferens para o vas deferens. As substâncias líquidas que então se formam, resultado da necrose, são reabsorvidas pelo epitélio do vas efferens, entrando novamente em circulação na hemolinfa; o epitélio possui um rabdório muito longo. A parte superior do conteúdo de cada folículo dispõe-se ao redor de grande célula apical cuja função principal deve ser a de uma atividade reguladora que está relacionada com a diferenciação das células do conjunto germinativo em espermiogônios primários e em núcleos das paredes dos cistos. Nos espermiogônios, serão verificadas 8 divisões de multiplicação, o que vai dar a formação de 256 espermiócitos, número êsse que depois das duas divisões de maturação, que se seguem, originará 1 024 espermídeos. Em seguida, são descritos os fenômenos que ocorrem durante a prófase e as duas divisões de maturação. Temos que admitir a existência de uma parasíndese. Pela formação das tétrades, pode-se concluir que a primeira divisão é reducional e a segunda equacional, existindo, pois, uma pré-redução. Triatoma infestans possui 22 cromosomas no espermiog

Determinants of Health Service Responsiveness in Community-Based Vector Surveillance for Chagas Disease in Guatemala, El Salvador, and Honduras

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Hashimoto, Ken; Zúniga, Concepción; Romero, Eduardo; Morales, Zoraida; Maguire, James H.

2015-01-01

Background Central American countries face a major challenge in the control of Triatoma dimidiata, a widespread vector of Chagas disease that cannot be eliminated. The key to maintaining the risk of transmission of Trypanosoma cruzi at lowest levels is to sustain surveillance throughout endemic areas. Guatemala, El Salvador, and Honduras integrated community-based vector surveillance into local health systems. Community participation was effective in detection of the vector, but some health services had difficulty sustaining their response to reports of vectors from the population. To date, no research has investigated how best to maintain and reinforce health service responsiveness, especially in resource-limited settings. Methodology/Principal Findings We reviewed surveillance and response records of 12 health centers in Guatemala, El Salvador, and Honduras from 2008 to 2012 and analyzed the data in relation to the volume of reports of vector infestation, local geography, demography, human resources, managerial approach, and results of interviews with health workers. Health service responsiveness was defined as the percentage of households that reported vector infestation for which the local health service provided indoor residual spraying of insecticide or educational advice. Eight potential determinants of responsiveness were evaluated by linear and mixed-effects multi-linear regression. Health service responsiveness (overall 77.4%) was significantly associated with quarterly monitoring by departmental health offices. Other potential determinants of responsiveness were not found to be significant, partly because of short- and long-term strategies, such as temporary adjustments in manpower and redistribution of tasks among local participants in the effort. Conclusions/Significance Consistent monitoring within the local health system contributes to sustainability of health service responsiveness in community-based vector surveillance of Chagas disease. Even with

Determinants of Health Service Responsiveness in Community-Based Vector Surveillance for Chagas Disease in Guatemala, El Salvador, and Honduras.

Science.gov (United States)

Hashimoto, Ken; Zúniga, Concepción; Romero, Eduardo; Morales, Zoraida; Maguire, James H

2015-01-01

Central American countries face a major challenge in the control of Triatoma dimidiata, a widespread vector of Chagas disease that cannot be eliminated. The key to maintaining the risk of transmission of Trypanosoma cruzi at lowest levels is to sustain surveillance throughout endemic areas. Guatemala, El Salvador, and Honduras integrated community-based vector surveillance into local health systems. Community participation was effective in detection of the vector, but some health services had difficulty sustaining their response to reports of vectors from the population. To date, no research has investigated how best to maintain and reinforce health service responsiveness, especially in resource-limited settings. We reviewed surveillance and response records of 12 health centers in Guatemala, El Salvador, and Honduras from 2008 to 2012 and analyzed the data in relation to the volume of reports of vector infestation, local geography, demography, human resources, managerial approach, and results of interviews with health workers. Health service responsiveness was defined as the percentage of households that reported vector infestation for which the local health service provided indoor residual spraying of insecticide or educational advice. Eight potential determinants of responsiveness were evaluated by linear and mixed-effects multi-linear regression. Health service responsiveness (overall 77.4%) was significantly associated with quarterly monitoring by departmental health offices. Other potential determinants of responsiveness were not found to be significant, partly because of short- and long-term strategies, such as temporary adjustments in manpower and redistribution of tasks among local participants in the effort. Consistent monitoring within the local health system contributes to sustainability of health service responsiveness in community-based vector surveillance of Chagas disease. Even with limited resources, countries can improve health service

Domestic animal hosts strongly influence human-feeding rates of the Chagas disease vector Triatoma infestans in Argentina.

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Ricardo E Gürtler

Full Text Available The host species composition in a household and their relative availability affect the host-feeding choices of blood-sucking insects and parasite transmission risks. We investigated four hypotheses regarding factors that affect blood-feeding rates, proportion of human-fed bugs (human blood index, and daily human-feeding rates of Triatoma infestans, the main vector of Chagas disease.A cross-sectional survey collected triatomines in human sleeping quarters (domiciles of 49 of 270 rural houses in northwestern Argentina. We developed an improved way of estimating the human-feeding rate of domestic T. infestans populations. We fitted generalized linear mixed-effects models to a global model with six explanatory variables (chicken blood index, dog blood index, bug stage, numbers of human residents, bug abundance, and maximum temperature during the night preceding bug catch and three response variables (daily blood-feeding rate, human blood index, and daily human-feeding rate. Coefficients were estimated via multimodel inference with model averaging.Median blood-feeding intervals per late-stage bug were 4.1 days, with large variations among households. The main bloodmeal sources were humans (68%, chickens (22%, and dogs (9%. Blood-feeding rates decreased with increases in the chicken blood index. Both the human blood index and daily human-feeding rate decreased substantially with increasing proportions of chicken- or dog-fed bugs, or the presence of chickens indoors. Improved calculations estimated the mean daily human-feeding rate per late-stage bug at 0.231 (95% confidence interval, 0.157-0.305.Based on the changing availability of chickens in domiciles during spring-summer and the much larger infectivity of dogs compared with humans, we infer that the net effects of chickens in the presence of transmission-competent hosts may be more adequately described by zoopotentiation than by zooprophylaxis. Domestic animals in domiciles profoundly affect the

Geographical Variation of Deltamethrin Susceptibility of Triatoma infestans (Hemiptera: Reduviidae) in Argentina With Emphasis on a Resistant Focus in the Gran Chaco.

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Fronza, G; Toloza, A C; Picollo, M I; Spillmann, C; Mougabure-Cueto, G A

2016-07-01

Chagas disease is one of the most important parasitic infections in Latin America. The main vector of the protozoan Trypanosoma cruzi in America is Triatoma infestans, a blood-sucking triatomine bug who is widely distributed in the Gran Chaco ecoregion. Control programs in endemic countries are focused in the elimination of triatomine vectors with pyrethroid insecticides. However, chemical control has failed in the Gran Chaco over the last two decades because of several factors. Previous studies have reported the evolution of different levels of resistance to deltamethrin in Tri. infestans Recently, very high resistance has been found in the central area of the Argentine Gran Chaco. However, the origin and the extension of this remarkably resistant focus remain unknown. The aim of this study was to evaluate the geographical variation of deltamethrin susceptibility of Tri. infestans in different endemic provinces of Argentina, with emphasis in the center of the Argentine Gran Chaco ecoregion where this main vector has not been reduced. Populations of Mendoza, San Juan, Santiago del Estero, and Tucumán provinces were all susceptible. Resistant populations were only detected in the province of Chaco, where a mosaic resistant focus was described at the Güemes Department. It was characterized into three pyrethroid resistance categories: susceptible, low, and highly resistant populations. We found the populations with the highest resistance levels to deltamethrin, with resistant ratios over 1000. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Body size and hosts of Triatoma infestans populations affect the size of bloodmeal contents and female fecundity in rural northwestern Argentina.

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Gürtler, Ricardo E; Fernández, María Del Pilar; Cecere, María Carla; Cohen, Joel E

2017-12-01

Human sleeping quarters (domiciles) and chicken coops are key source habitats of Triatoma infestans-the principal vector of the infection that causes Chagas disease-in rural communities in northern Argentina. Here we investigated the links among individual bug bloodmeal contents (BMC, mg), female fecundity, body length (L, mm), host blood sources and habitats. We tested whether L, habitat and host blood conferred relative fitness advantages using generalized linear mixed-effects models and a multimodel inference approach with model averaging. The data analyzed include 769 late-stage triatomines collected in 120 sites from six habitats in 87 houses in Figueroa, Santiago del Estero, during austral spring. L correlated positively with other body-size surrogates and was modified by habitat type, bug stage and recent feeding. Bugs from chicken coops were significantly larger than pig-corral and kitchen bugs. The best-fitting model of log BMC included habitat, a recent feeding, bug stage, log Lc (mean-centered log L) and all two-way interactions including log Lc. Human- and chicken-fed bugs had significantly larger BMC than bugs fed on other hosts whereas goat-fed bugs ranked last, in consistency with average blood-feeding rates. Fecundity was maximal in chicken-fed bugs from chicken coops, submaximal in human- and pig-fed bugs, and minimal in goat-fed bugs. This study is the first to reveal the allometric effects of body-size surrogates on BMC and female fecundity in a large set of triatomine populations occupying multiple habitats, and discloses the links between body size, microsite temperatures and various fitness components that affect the risks of transmission of Trypanosoma cruzi.

Body size and hosts of Triatoma infestans populations affect the size of bloodmeal contents and female fecundity in rural northwestern Argentina.

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Ricardo E Gürtler

2017-12-01

Full Text Available Human sleeping quarters (domiciles and chicken coops are key source habitats of Triatoma infestans-the principal vector of the infection that causes Chagas disease-in rural communities in northern Argentina. Here we investigated the links among individual bug bloodmeal contents (BMC, mg, female fecundity, body length (L, mm, host blood sources and habitats. We tested whether L, habitat and host blood conferred relative fitness advantages using generalized linear mixed-effects models and a multimodel inference approach with model averaging. The data analyzed include 769 late-stage triatomines collected in 120 sites from six habitats in 87 houses in Figueroa, Santiago del Estero, during austral spring. L correlated positively with other body-size surrogates and was modified by habitat type, bug stage and recent feeding. Bugs from chicken coops were significantly larger than pig-corral and kitchen bugs. The best-fitting model of log BMC included habitat, a recent feeding, bug stage, log Lc (mean-centered log L and all two-way interactions including log Lc. Human- and chicken-fed bugs had significantly larger BMC than bugs fed on other hosts whereas goat-fed bugs ranked last, in consistency with average blood-feeding rates. Fecundity was maximal in chicken-fed bugs from chicken coops, submaximal in human- and pig-fed bugs, and minimal in goat-fed bugs. This study is the first to reveal the allometric effects of body-size surrogates on BMC and female fecundity in a large set of triatomine populations occupying multiple habitats, and discloses the links between body size, microsite temperatures and various fitness components that affect the risks of transmission of Trypanosoma cruzi.

Assessing the vulnerability of Brazilian municipalities to the vectorial transmission of Trypanosoma cruzi using multi-criteria decision analysis.

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Vinhaes, Márcio Costa; de Oliveira, Stefan Vilges; Reis, Priscilleyne Ouverney; de Lacerda Sousa, Ana Carolina; Silva, Rafaella Albuquerque E; Obara, Marcos Takashi; Bezerra, Cláudia Mendonça; da Costa, Veruska Maia; Alves, Renato Vieira; Gurgel-Gonçalves, Rodrigo

2014-09-01

Despite the dramatic reduction in Trypanosoma cruzi vectorial transmission in Brazil, acute cases of Chagas disease (CD) continue to be recorded. The identification of areas with greater vulnerability to the occurrence of vector-borne CD is essential to prevention, control, and surveillance activities. In the current study, data on the occurrence of domiciliated triatomines in Brazil (non-Amazonian regions) between 2007 and 2011 were analyzed. Municipalities' vulnerability was assessed based on socioeconomic, demographic, entomological, and environmental indicators using multi-criteria decision analysis (MCDA). Overall, 2275 municipalities were positive for at least one of the six triatomine species analyzed (Panstrongylus megistus, Triatoma infestans, Triatoma brasiliensis, Triatoma pseudomaculata, Triatoma rubrovaria, and Triatoma sordida). The municipalities that were most vulnerable to vector-borne CD were mainly in the northeast region and exhibited a higher occurrence of domiciliated triatomines, lower socioeconomic levels, and more extensive anthropized areas. Most of the 39 new vector-borne CD cases confirmed between 2001 and 2012 in non-Amazonian regions occurred within the more vulnerable municipalities. Thus, MCDA can help to identify the states and municipalities that are most vulnerable to the transmission of T. cruzi by domiciliated triatomines, which is critical for directing adequate surveillance, prevention, and control activities. The methodological approach and results presented here can be used to enhance CD surveillance in Brazil. Copyright © 2014 Elsevier B.V. All rights reserved.

Hidden sylvatic foci of the main vector of Chagas disease Triatoma infestans: threats to the vector elimination campaign?

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Leonardo A Ceballos

2011-10-01

Full Text Available Establishing the sources of reinfestation after residual insecticide spraying is crucial for vector elimination programs. Triatoma infestans, traditionally considered to be limited to domestic or peridomestic (abbreviated as D/PD habitats throughout most of its range, is the target of an elimination program that has achieved limited success in the Gran Chaco region in South America.During a two-year period we conducted semi-annual searches for triatomine bugs in every D/PD site and surrounding sylvatic habitats after full-coverage spraying of pyrethroid insecticides of all houses in a well-defined rural area in northwestern Argentina. We found six low-density sylvatic foci with 24 T. infestans in fallen or standing trees located 110-2,300 m from the nearest house or infested D/PD site detected after insecticide spraying, when house infestations were rare. Analysis of two mitochondrial gene fragments of 20 sylvatic specimens confirmed their species identity as T. infestans and showed that their composite haplotypes were the same as or closely related to D/PD haplotypes. Population studies with 10 polymorphic microsatellite loci and wing geometric morphometry consistently indicated the occurrence of unrestricted gene flow between local D/PD and sylvatic populations. Mitochondrial DNA and microsatellite sibship analyses in the most abundant sylvatic colony revealed descendents from five different females. Spatial analysis showed a significant association between two sylvatic foci and the nearest D/PD bug population found before insecticide spraying.Our study shows that, despite of its high degree of domesticity, T. infestans has sylvatic colonies with normal chromatic characters (not melanic morphs highly connected to D/PD conspecifics in the Argentinean Chaco. Sylvatic habitats may provide a transient or permanent refuge after control interventions, and function as sources for D/PD reinfestation. The occurrence of sylvatic foci of T. infestans in

Strong host-feeding preferences of the vector Triatoma infestans modified by vector density: implications for the epidemiology of Chagas disease.

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Ricardo E Gürtler

2009-05-01

Full Text Available Understanding the factors that affect the host-feeding preferences of triatomine bugs is crucial for estimating transmission risks and predicting the effects of control tactics targeting domestic animals. We tested whether Triatoma infestans bugs prefer to feed on dogs vs. chickens and on dogs vs. cats and whether vector density modified host choices and other vital rates under natural conditions.Two host choice experiments were conducted in small caged huts with two rooms between which bugs could move freely. Matched pairs of dog-chicken (six and dog-cat (three were assigned randomly to two levels of vector abundance and exposed to starved bugs during three nights. Bloodmeals from 1,160 bugs were tested by a direct enzyme-linked immunosorbent assay.Conditional logistic regression showed that dogs were highly preferred over chickens or cats and that vector density modified host-feeding choices. The relative risk of a bug being blood-engorged increased significantly when it fed only on dog rather than chicken or cat. Bugs achieved higher post-exposure weight at higher vector densities and successive occasions, more so if they fed on a dog rather than on a cat.Our findings strongly refute the hypothesis that T. infestans prefers to blood-feed on chickens rather than dogs. An increase in dog or cat availability or accessibility will increase the rate of bug feeding on them and exert strong non-linear effects on R(0. When combined with between-dog heterogeneities in exposure, infection, and infectiousness, the strong bug preference for dogs can be exploited to target dogs in general, and even the specific individuals that account for most of the risk, with topical lotions or insecticide-impregnated collars to turn them into baited lethal traps or use them as transmission or infestation sentinels based on their immune response to Trypanosoma cruzi or bug salivary antigens.

Spatial and temporal distribution of house infestation by Triatoma infestans in the Toro Toro municipality, Potosi, Bolivia.

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Espinoza Echeverria, Jorge; Rodriguez, Antonio Nogales; Cortez, Mirko Rojas; Diotaiuti, Liléia Gonçalves; Gorla, David E

2017-02-02

Triatoma infestans is the main vector of Trypanosoma cruzi in Bolivia. The species is present both in domestic and peridomestic structures of rural areas, and in wild ecotopes of the Andean valleys and the Great Chaco. The identification of areas persistently showing low and high house infestation by the vector is important for the management of vector control programs. This study aimed at analyzing the temporal and spatial distribution of house infestation by T. infestans in the Toro Toro municipality (Potosi, Bolivia) between 2009 and 2014, and its association with environmental variables. House infestation and T. infestans density were calculated from entomological surveys of houses in the study area, using a fixed-time effort sampling technique. The spatial heterogeneity of house infestation was evaluated using the SatScan statistic. Association between house infestation with Bioclim variables (Worldclim database) and altitude was analyzed using a generalized linear model (GLM) with a logit link. Model selection was based on the Akaike information criteria after eliminating collinearity between variables using the variable inflation factor. The final model was used to create a probability map of house infestation for the Toro Toro municipality. A total of 73 communities and 16,489 house evaluation events were analyzed. Presence of T. infestans was recorded on 480 house evaluation events, giving an overall annual infestation of 2.9% during the studied period (range 1.5-5.4% in 2009 and 2012). Vector density remained at about 1.25 insects/ house. Infestation was highly aggregated in five clusters, including 11 communities. Relative risk of infestation within these clusters was 1.7-3.9 times the value for the regional average. Four environmental variables were identified as good descriptors of house infestation, explaining 57% of house infestation variability. The model allowed the estimation of a house infestation surface for the Toro Toro municipality. This

Distinctive Citizenship

DEFF Research Database (Denmark)

Kaur, Ravinder

2009-01-01

The refugee, in India's Partition history, appears as an enigmatic construct - part pitiful, part heroic, though mostly shorn of agency - representing the surface of the human tragedy of Partition. Yet this archetype masks the undercurrent of social distinctions that produced hierarchies of post...

Blood meal sources of wild and domestic Triatoma infestans (Hemiptera: Reduviidae) in Bolivia: connectivity between cycles of transmission of Trypanosoma cruzi.

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Buitrago, Rosio; Bosseno, Marie-France; Depickère, Stéphanie; Waleckx, Etienne; Salas, Renata; Aliaga, Claudia; Barnabé, Christian; Brenière, Simone Frédérique

2016-04-18

Chagas disease is a major public health problem in Latin America. Its etiologic agent, Trypanosoma cruzi, is mainly transmitted through the contaminated faeces of blood-sucking insects called triatomines. Triatoma infestans is the main vector in various countries in South America and recently, several foci of wild populations of this species have been described in Bolivia and other countries. These wild populations are suspected of affecting the success of insecticide control campaigns being carried out in South America. To assess the risk that these T. infestans populations pose to human health, it is helpful to determine blood meal sources. In the present work, blood meals were identified in various Bolivian wild T. infestans populations and in three specific areas, in both wild and intra-peridomestic populations to assess the links between wild and domestic cycles of T. cruzi transmission. PCR-HDA and sequencing of Cytb gene were used to identify these blood meal sources. Fourteen vertebrate species were identified as wild blood meal sources. Of those, the most prevalent species were two Andean endemic rodents, Octodontomys gliroides (36%) and Galea musteloides (30%), while humans were the third most prevalent source (18.7%). Of 163 blood meals from peridomestic areas, more than half were chickens, and the others were generally domestic animals or humans. Interestingly, blood from wild animals was identified in triatomines captured in the peridomestic and domestic environment, and blood from domestic animals was found in triatomines captured in the wild, revealing links between wild and domestic cycles of T. cruzi transmission. The current study suggests that wild T. infestans attack humans in the wild, but is also able to bite humans in domestic settings before going back to its natural environment. These results support the risk to human health posed by wild populations of T. infestans.

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

Counselor Identity: Conformity or Distinction?

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McLaughlin, Jerry E.; Boettcher, Kathryn

2009-01-01

The authors explore 3 debates in other disciplines similar to counseling's identity debate in order to learn about common themes and outcomes. Conformity, distinction, and cohesion emerged as common themes. They conclude that counselors should retain their distinctive, humanistic approach rather than conforming to the dominant, medical approach.

Peridomiciliary colonies of Triatoma vitticeps (Stal, 1859 (Hemiptera, Reduviidae, Triatominae infected with Trypanosoma cruzi in rural areas of the state of Espírito Santo, Brazil

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Claudiney Biral dos Santos

2005-08-01

Full Text Available In Brazil, the colonization of human dwellings by triatomines occurs in areas with native vegetation of the caatinga or cerrado types. In areas of Atlantic forest such as in the Brazilian state of Espírito Santo, there are no species adapted to live in human habitations. The few autochthonous cases of Chagas disease encountered in Espírito Santo have been attributed to adult specimens of Triatoma vitticeps that invade houses from forest remnants. In recent years, the entomology unit of the Espírito Santo State Health Secretariat has recorded nymphs infected with flagellates similar to Trypanosoma cruzi in rural localities. Entomological surveys were carried out in the residences and outbuildings in which the insects were found, and serological examinations for Chagas disease performed on the inhabitants. Four colonies were found, all associated with nests of opossums (Didelphis aurita, 111 specimens of T. vitticeps, and 159 eggs being collected. All the triatomines presented flagellates in their frass. Mice inoculated with the faeces presented trypomastigotes in the circulating blood and groups of amastigotes in the cardiac muscle fibres. Serological tests performed on the inhabitants were negative for T. cruzi. Even with the intense devastation of the forest in Espírito Santo, there are no indications of change in the sylvatic habits of T. vitticeps. Colonies of this insect associated with opossum nests would indicate an expansion of the sylvatic environment into the peridomicile.

Seroprevalencia de anticuerpos contra Trypanosoma cruzi y su asociación con factores de riesgo en menores de 18 años de Veracruz, México Seroprevalence of Trypanosoma cruzi antibodies and associated risk factors among the population under 18 years of age in Veracruz, Mexico

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Paz María Salazar

2007-08-01

Full Text Available OBJETIVOS: Determinar la prevalencia de anticuerpos contra Trypanosoma cruzi en menores de 18 años del estado de Veracruz, México, e identificar los factores de riesgo asociados con las características de la vivienda y la presencia y distribución del agente transmisor. MÉTODOS: Estudio epidemiológico transversal en la población menor de 18 años que vivía en 10 de las 11 jurisdicciones sanitarias del estado de Veracruz, México, entre 2000 y 2001. La presencia de anticuerpos contra T. cruzi se determinó mediante una prueba de hemaglutinación indirecta (HAI y un ensayo inmunoenzimático indirecto tipo ELISA en muestras de suero tomadas en papel de filtro y se confirmaron mediante las pruebas de HAI, ELISA e inmunofluorescencia indirecta (IFI en muestras de suero. Se aplicó un cuestionario para evaluar las condiciones de la vivienda y se calcularon los índices entomológicos de triatominos intra y peridomiciliarios. Los resultados se evaluaron mediante análisis bifactorial y multifactorial por regresión logística no condicional. RESULTADOS: De las 150 personas inicialmente reactivas, 14 resultaron positivas (5 mediante la prueba de HAI, ELISA e IFI; 6 por HAI y ELISA y 3 por ELISA e IFI, para una prevalencia general de 0,91% (IC95%: 0,85% a 0,94%. Los casos positivos residían en cinco jurisdicciones sanitarias y la mayor prevalencia se encontró en Tuxpan: 5,2% (IC95%: 1,2% a 9,0%. Los factores de riesgo fueron el haber visto chinches dentro de la vivienda y los techos con fisuras. La única especie del agente transmisor capturada fue Triatoma dimidiata. Los índices entomológicos de infestación, colonización e infección natural fueron: 10,9%, 50,0% y 9,0%, respectivamente. CONCLUSIONES: Se confirmó la transmisión vectorial activa de la infección en el estado de Veracruz, México, con una seroprevalencia general de anticuerpos contra T. cruzi en menores de 18 años de 0,91%. Se debe seguir atentamente la seroprevalencia en

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

The pursuit of optimal distinctiveness and consumer preferences.

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He, Lingnan; Cong, Feng; Liu, Yanping; Zhou, Xinyue

2010-10-01

This article investigates the effect of optimal distinctiveness on consumer product consumption. The authors argue that consumers acquire and display material possessions to restore their optimal levels of distinctiveness. Results showed that placing consumers in a state of low distinctiveness increased desire to acquire distinctive products, whereas perceptions of high distinctiveness reduced desire to acquire such products. Consumers' desire for distinctiveness-related products held true for various consumer choices, including willingness to pay more for limited-edition products and preference for unpopular gifts. This finding has implications for understanding consumer choice in expressing identity. © 2010 The Authors. Scandinavian Journal of Psychology © 2010 The Scandinavian Psychological Associations.

Perfil alimentario de Triatoma rubrovaria (Blanchard, 1843 (Hemiptera, Triatominae en ámbitos peridomiciliarios, de una localidad rural de Uruguay Feeding patterns of Triatoma rubrovaria (Blanchard, 1843 (Hemiptera, Triatominae in peridomestic habitats, in a rural area of Uruguay

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Roberto Salvatella

1994-08-01

Full Text Available En una localidad con población rural dispersa ("La Bolsa", 3ª seccional, dpto. de Artigas, Uruguay se estudió, en ámbitos peridomiciliarios, el perfil alimentario de T. rubrovaria (triatomíneo silvestre y potencial vector secundario de colonización intradomiciliaria, utilizándose la técnica de doble difusión en agar, enfrentando contenido promesentérico frente a un panel de 13 sueros. Se pudo detectar en 120 insectos 251 identificaciones de fuente hematofágica con alimentación predominante en mamíferos (73%, pero marcado eclectismo alimentario (mamíferos, aves, reptiles y cucarachas, incluyendo hematofagia sobre seres humanos en un 8% de las identificaciones totales. La micropredación de hemolinfa lo ubicaría en una situación evolutiva primitiva, intermedia entre predator/entomófago y triatomineo/hematófago, que comparte con T. circunmaculata. Los mamíferos detectados con mayor frecuencia fueron dasipódidos y bóvidos, aunque la fuente hematofágica, salvo en los adultos alados, se constituye en un fenómeno de proximidad ocasional por cohabitación de un mismo habitat. La frecuencia de alimentación sobre hombre, hallada en un ambiente peridomiciliario, aporta un importante elemento a su capacidad vectorial potencial. En el análisis espacial de las dietas se muestra al peridomicilio como un área de interacción de hospederos domésticos, silvestres y sinantrópicos. La infección tripanosómica fue mínima comparada con las altas tasas de infección de ámbitos silvestres.It has been studied the feeding patterns of Triatoma rubrovaria (wild triatominae bug, and intradomiciliary secondary vector of T. cruzi in a rural area of "La Bolsa" (Department of Artigas. Agar double diffusion test were used for analyze the blood meal, from 120 insects, which were confronted to 13 antisera. It has 251 identify blood meals, and the most frequently was mamalian host (73%, but it has a variable source of feeding (mammals, birds, reptils

Genotype diversity of Trypanosoma cruzi in small rodents and Triatoma sanguisuga from a rural area in New Orleans, Louisiana.

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Herrera, Claudia P; Licon, Meredith H; Nation, Catherine S; Jameson, Samuel B; Wesson, Dawn M

2015-02-24

Chagas disease is an anthropozoonosis caused by the protozoan parasite Trypanosoma cruzi that represents a major public health problem in Latin America. Although the United States is defined as non-endemic for Chagas disease due to the rarity of human cases, the presence of T. cruzi has now been amply demonstrated as enzootic in different regions of the south of the country from Georgia to California. In southeastern Louisiana, a high T. cruzi infection rate has been demonstrated in Triatoma sanguisuga, the local vector in this area. However, little is known about the role of small mammals in the wild and peridomestic transmission cycles. This study focused on the molecular identification and genotyping of T. cruzi in both small rodents and T. sanguisuga from a rural area of New Orleans, Louisiana. DNA extractions were prepared from rodent heart, liver, spleen and skeletal muscle tissues and from cultures established from vector feces. T. cruzi infection was determined by standard PCR using primers specific for the minicircle variable region of the kinetoplastid DNA (kDNA) and the highly repetitive genomic satellite DNA (satDNA). Genotyping of discrete typing units (DTUs) was performed by amplification of mini-exon and 18S and 24Sα rRNA genes and subsequent sequence analysis. The DTUs TcI, TcIV and, for the first time, TcII, were identified in tissues of mice and rats naturally infected with T. cruzi captured in an area of New Orleans, close to the house where the first human case of Chagas disease was reported in Louisiana. The T. cruzi infection rate in 59 captured rodents was 76%. The frequencies of the detected DTUs in such mammals were TcI 82%, TcII 22% and TcIV 9%; 13% of all infections contained more than one DTU. Our results indicate a probable presence of a considerably greater diversity in T. cruzi DTUs circulating in the southeastern United States than previously reported. Understanding T. cruzi transmission dynamics in sylvatic and peridomestic cycles

Distinctiveness of Saudi Arabian EFL Learners

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Manssour Habbash

2016-04-01

Full Text Available In view of the increasing concern among English language teachers dealing with students from Saudi Arabia, as it manifests in TESOL community discussions, about the uniqueness of Saudi Arabian EFL learners, this paper attempts to document the outcome of a study of their distinctiveness from the perspective of expatriate teachers working for PYPs (Preparatory Year Programs in Saudi Arabia. This study examines the distinctiveness with regard to the learning attitudes of Saudi students that are often cultivated by the culture and academic environment in their homeland. Employing an emic approach for collecting the required data an analysis was carried out in light of the other studies on ‘education’ in Saudi Arabia that have particular reference to the factors that can positively influence student motivation, student success and the academic environment. The findings were used in constructing the rationale behind such distinctiveness. Assuming that the outcome of the discussion on the findings of this exploration can be helpful for teachers in adapting their teaching methodology and improving their teacher efficacy in dealing with students both from the kingdom and in the kingdom, some recommendations are made. Keywords: China Distinctiveness, Saudi Arabian University context, Expatriate teachers’ perspective, Distinctiveness Theory

Social conformity despite individual preferences for distinctiveness.

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Smaldino, Paul E; Epstein, Joshua M

2015-03-01

We demonstrate that individual behaviours directed at the attainment of distinctiveness can in fact produce complete social conformity. We thus offer an unexpected generative mechanism for this central social phenomenon. Specifically, we establish that agents who have fixed needs to be distinct and adapt their positions to achieve distinctiveness goals, can nevertheless self-organize to a limiting state of absolute conformity. This seemingly paradoxical result is deduced formally from a small number of natural assumptions and is then explored at length computationally. Interesting departures from this conformity equilibrium are also possible, including divergence in positions. The effect of extremist minorities on these dynamics is discussed. A simple extension is then introduced, which allows the model to generate and maintain social diversity, including multimodal distinctiveness distributions. The paper contributes formal definitions, analytical deductions and counterintuitive findings to the literature on individual distinctiveness and social conformity.

Trypanosoma cruzi reservoir—triatomine vector co-occurrence networks reveal meta-community effects by synanthropic mammals on geographic dispersal

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Carlos N. Ibarra-Cerdeña

2017-04-01

Full Text Available Contemporary patterns of land use and global climate change are modifying regional pools of parasite host species. The impact of host community changes on human disease risk, however, is difficult to assess due to a lack of information about zoonotic parasite host assemblages. We have used a recently developed method to infer parasite-host interactions for Chagas Disease (CD from vector-host co-occurrence networks. Vector-host networks were constructed to analyze topological characteristics of the network and ecological traits of species’ nodes, which could provide information regarding parasite regional dispersal in Mexico. Twenty-eight triatomine species (vectors and 396 mammal species (potential hosts were included using a data-mining approach to develop models to infer most-likely interactions. The final network contained 1,576 links which were analyzed to calculate centrality, connectivity, and modularity. The model predicted links of independently registered Trypanosoma cruzi hosts, which correlated with the degree of parasite-vector co-occurrence. Wiring patterns differed according to node location, while edge density was greater in Neotropical as compared to Nearctic regions. Vectors with greatest public health importance (i.e., Triatoma dimidiata, T. barberi, T. pallidipennis, T. longipennis, etc, did not have stronger links with particular host species, although they had a greater frequency of significant links. In contrast, hosts classified as important based on network properties were synanthropic mammals. The latter were the most common parasite hosts and are likely bridge species between these communities, thereby integrating meta-community scenarios beneficial for long-range parasite dispersal. This was particularly true for rodents, >50% of species are synanthropic and more than 20% have been identified as T. cruzi hosts. In addition to predicting potential host species using the co-occurrence networks, they reveal regions with

Residual effect of a micro-encapsulated formulation of organophosphates and piriproxifen on the mortality of deltamethrin resistant Triatoma infestans populations in rural houses of the Bolivian Chaco region

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Abraham Gemio Alarico

2010-09-01

Full Text Available The Bolivian Chaco is part of the endemic region of Chagas disease and an area where pyrethroid resistant Triatoma infestans (Hemiptera: Reduviidae populations has been reported. The World Health Organization identified these resistant populations as an important focus for research. The objective of this study was to evaluate the residual effect of a micro-encapsulated formulation containing organophosphate active ingredients and a juvenile hormone analogue (Inesfly 5A IGR on the mortality of T. infestans. Studies took place in rural houses of the Bolivian Chaco that were treated up to 34 months before and evaluated the susceptibility to pyrethroids of the offspring of field collected insects. Thirty houses were randomly selected within three communities to carry out wall bio-assays with T. infestans nymphs. Mortality was recorded 24, 48 and 72 h after wall contact. Eggs laid by females collected in the area were used to obtain first-instar nymphs and carry out pyrethroid susceptibility tests. The wall bio-assays showed that the micro-encapsulated insecticide eliminates T. infestans populations and produces detectable mortality of insects exposed to walls treated 34 months prior to the tests. The discriminant dose of deltamethrin (0.01 mg/mL showed 65% nymph survival, whereas at the highest tested dose (1.0 mg/mL 14% of the nymphs survived. These results show that Inesfly 5A IGR is an appropriate tool for the elimination of intradomestic and peridomestic populations of T. infestans resistant to pyrethroids.

Visual distinctiveness can enhance recency effects.

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Bornstein, B H; Neely, C B; LeCompte, D C

1995-05-01

Experimental efforts to meliorate the modality effect have included attempts to make the visual stimulus more distinctive. McDowd and Madigan (1991) failed to find an enhanced recency effect in serial recall when the last item was made more distinct in terms of its color. In an attempt to extend this finding, three experiments were conducted in which visual distinctiveness was manipulated in a different manner, by combining the dimensions of physical size and coloration (i.e., whether the stimuli were solid or outlined in relief). Contrary to previous findings, recency was enhanced when the size and coloration of the last item differed from the other items in the list, regardless of whether the "distinctive" item was larger or smaller than the remaining items. The findings are considered in light of other research that has failed to obtain a similar enhanced recency effect, and their implications for current theories of the modality effect are discussed.

On Hobbes’s distinction of accidents

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Lupoli Agostino

2012-06-01

Full Text Available An interpolation introduced by K. Schuhmann in his critical edition of "De corpore" (chap. VI, § 13 diametrically overturns the meaning of Hobbes’s doctrine of distinction of accidents in comparison with all previous editions. The article focuses on the complexity of this crucial juncture in "De corpore" argument on which depends the interpretation of Hobbes’s whole conception of science. It discusses the reasons pro and contra Schuhmann’s interpolation and concludes against it, because it is not compatible with the rationale underlying the complex architecture of "De corpore", which involves a symmetry between the ‘logical’ distinction of accidents and the ‘metaphysical’ distinction of phantasms.

Toxicological, Enzymatic, and Molecular Assessment of the Insecticide Susceptibility Profile of Triatoma infestans (Hemiptera: Reduviidae, Triatominae) Populations From Rural Communities of Santa Cruz, Bolivia.

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Santo-Orihuela, Pablo L; Vassena, Claudia V; Carvajal, Guillermo; Clark, Eva; Menacho, Silvio; Bozo, Ricardo; Gilman, Robert H; Bern, Caryn; Marcet, Paula L

2017-01-01

A wide range of insecticide resistance profiles has been reported across Bolivian domestic and sylvatic populations of Triatoma infestans (Klug, 1834) (Hemiptera, Reduviidae), including some with levels proven to be a threat for vector control. In this work, the insecticide profile of domestic T. infestans was studied with standardized toxicological bioassays, in an area that has not undergone consistent vector control. F1 first-instar nymphs hatched in laboratory from bugs captured in three communities from the Santa Cruz Department were evaluated with different insecticides. Moreover, the enzymatic activity of esterases and cytochrome P450 monooxygenases was measured in individual insects to evaluate the possible mechanism of metabolic resistance to pyrethroids. In addition, the DNA sequence of sodium channel gene (kdr) was screened for two point mutations associated with pyrethroid resistance previously reported in T. infestans.All populations showed reduced susceptibility to deltamethrin and α-cypermethrin, albeit the RR50 values varied significantly among them. Increased P450 monooxygenases and permethrate esterases suggest the contribution, as detoxifying mechanisms, to the observed resistance to deltamethrin in all studied populations. No individuals presented either mutation associated to resistance in the kdr gene. The level of susceptibility to α-cypermethrin, the insecticide used by the local vector control program, falls within an acceptable range to continue its use in these populations. However, the observed RR50 values evidence the possibility of selection for resistance to pyrethroids, especially to deltamethrin. Consequently, the use of pyrethroid insecticides should be closely monitored in these communities, which should be kept under entomological surveillance and sustained interventions. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email

Estudos anatômicos e histológicos sôbre a subfamília Triatominae (Heteroptera, Reduviidae: Parte XXII. A estrutura da córnea de Triatoma Infestans

Directory of Open Access Journals (Sweden)

Rudolf Barth

1965-01-01

Full Text Available Descreve-se a composição da córnea do ôlho de Triatoma infestans, chegando-se aos seguintes resultados: 1 - A faceta de um omatídeo consta de uma lente quitinosa central, incluída dentro de um prima hexagonal cuticular que, em virtude da sua construção, contribui decisivamente para o isolamento ótico da lente. 2 - A lente é formada (1 pela epicutícula superficial, muito fina, (2 pela exocutícula quase homogênea e (3 pela endocutícula lamelada. A exocutícula apresenta-se em forma de uma lente coletora, sem qualquer pigmento. A endocutícula, também sem pigmentos, compõe-se de numerosas (50 a 80 lamelas cuticulares, em forma de cones encaixados, um no outro, de modo que as extremidades dos cones se encontram no eixo ótico da lente. A lente corresponde à um cristal monaxial. 3 - A córnea é a continuação da cutícula da cabeça; as camadas desta, compostas de tiras quitinosas, coladas por proteínas entre si, desintegram0se em numerosas lamelas. 4 - As propriedades óticas das lentes correspondem às de um cilindro de lentes no sentido de EXNER (1891. 5 - Os omatídeos centrais do ôlho são homocêntrico, os periféricos heterocêntricos com eixo ótico curvado.

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.

Ecohealth Interventions for Chagas Disease Prevention in Central ...

International Development Research Centre (IDRC) Digital Library (Canada)

This had the effect of preventing reinfestation and modifying the insects' feeding practices such that they switched from human to chicken blood meals (chickens do not transmit the disease). This project will test the insect control program in selected border areas in the three countries where T. dimidiata is highly prevalent ...

What makes health promotion research distinct?

Science.gov (United States)

Woodall, James; Warwick-Booth, Louise; South, Jane; Cross, Ruth

2018-02-01

There have been concerns about the decline of health promotion as a practice and discipline and, alongside this, calls for a clearer articulation of health promotion research and what, if anything, makes it distinct. This discussion paper, based on a review of the literature, the authors' own experiences in the field, and a workshop delivered by two of the authors at the 8th Nordic Health Promotion Conference, seeks to state the reasons why health promotion research is distinctive. While by no means exhaustive, the paper suggests four distinctive features. The paper hopes to be a catalyst to enable health promotion researchers to be explicit in their practice and to begin the process of developing an agreed set of research principles.

Biological Control of the Chagas Disease Vector Triatoma infestans with the Entomopathogenic Fungus Beauveria bassiana Combined with an Aggregation Cue: Field, Laboratory and Mathematical Modeling Assessment.

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Lucas Forlani

2015-05-01

Full Text Available Current Chagas disease vector control strategies, based on chemical insecticide spraying, are growingly threatened by the emergence of pyrethroid-resistant Triatoma infestans populations in the Gran Chaco region of South America.We have already shown that the entomopathogenic fungus Beauveria bassiana has the ability to breach the insect cuticle and is effective both against pyrethroid-susceptible and pyrethroid-resistant T. infestans, in laboratory as well as field assays. It is also known that T. infestans cuticle lipids play a major role as contact aggregation pheromones. We estimated the effectiveness of pheromone-based infection boxes containing B. bassiana spores to kill indoor bugs, and its effect on the vector population dynamics. Laboratory assays were performed to estimate the effect of fungal infection on female reproductive parameters. The effect of insect exuviae as an aggregation signal in the performance of the infection boxes was estimated both in the laboratory and in the field. We developed a stage-specific matrix model of T. infestans to describe the fungal infection effects on insect population dynamics, and to analyze the performance of the biopesticide device in vector biological control.The pheromone-containing infective box is a promising new tool against indoor populations of this Chagas disease vector, with the number of boxes per house being the main driver of the reduction of the total domestic bug population. This ecologically safe approach is the first proven alternative to chemical insecticides in the control of T. infestans. The advantageous reduction in vector population by delayed-action fungal biopesticides in a contained environment is here shown supported by mathematical modeling.

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.

A Triatoma maculata (Hemiptera, Reduviidae, Triatominae population from Roraima, Amazon region, Brazil, has some bionomic characteristics of a potential Chagas disease vector Uma população de Triatoma maculata (Hemiptera, Reduviidae, Triatominae proveniente de Roraima, Amazônia, Brasil, possui algumas características bionômicas de vetor potencial de doença de Chagas

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José Francisco Luitgards-Moura

2005-06-01

Full Text Available Even though Chagas disease is rare in the Brazilian Amazon, the conditions for the establishment of domiciliated cycles prevail in many areas where triatomines are of frequent occurrence. In Roraima, a previous serological and entomological survey in three agricultural settlements showed the existence of all transmission cycle elements, i.e., individuals infected by Trypanosoma cruzi, triatomine species previously found harboring T. cruzi in the broader Amazon region of neighboring countries and, domicile/ peridomicile conditions favorable to triatomine colonization. Triatoma maculata was the most frequent species, found in chicken houses in the peridomicile and sporadically within residences. Aiming to investigate the possibility of T. maculata to possess the potentiality to transmit T. cruzi in the area, bionomic characteristics were studied under laboratory conditions. These were feeding frequency, time for defecation after a blood meal, time elapsed in voluntary fasting pre- and pos-ecdysis, moulting time periods, pre-oviposition and oviposition periods and index of oviposition, incubation period, egg viability, longevity and mortality rate. Results show that the Passarão population of T. maculata should be considered a potential vector of T. cruzi since it shows a capacity to infest artificial ecotopes in the peridomicile, to carry out large number of meals during the nymphal cycle, to have a relatively short developmental cycle capable of producing 2.9 generations/year, to blood source eclecticism, to defecate immediately after the blood meal while still on the host and to the fact that has been previously found naturally infected by T.cruzi.A doença de Chagas é de rara ocorrência na Região Amazônica Brasileira, onde contudo as condições para o estabelecimento de ciclos domésticos existem. Um estudo previamente realizado em áreas de colonização agrícola no Estado de Roraima, mostrou a possibilidade de ciclos autóctones de

Molecular Techniques for Dicistrovirus Detection without RNA Extraction or Purification

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Jailson F. B. Querido

2013-01-01

Full Text Available Dicistroviridae is a new family of small, nonenveloped, and +ssRNA viruses pathogenic to both beneficial arthropods and insect pests as well. Triatoma virus (TrV, a dicistrovirus, is a pathogen of Triatoma infestans (Hemiptera: Reduviidae, one of the main vectors of Chagas disease. In this work, we report a single-step method to identify TrV, a dicistrovirus, isolated from fecal samples of triatomines. The identification method proved to be quite sensitive, even without the extraction and purification of RNA virus.

Tagging like Humans: Diverse and Distinct Image Annotation

KAUST Repository

Wu, Baoyuan

2018-03-31

In this work we propose a new automatic image annotation model, dubbed {\\\\bf diverse and distinct image annotation} (D2IA). The generative model D2IA is inspired by the ensemble of human annotations, which create semantically relevant, yet distinct and diverse tags. In D2IA, we generate a relevant and distinct tag subset, in which the tags are relevant to the image contents and semantically distinct to each other, using sequential sampling from a determinantal point process (DPP) model. Multiple such tag subsets that cover diverse semantic aspects or diverse semantic levels of the image contents are generated by randomly perturbing the DPP sampling process. We leverage a generative adversarial network (GAN) model to train D2IA. Extensive experiments including quantitative and qualitative comparisons, as well as human subject studies, on two benchmark datasets demonstrate that the proposed model can produce more diverse and distinct tags than the state-of-the-arts.

Creating fair lineups for suspects with distinctive features

OpenAIRE

Zarkadi, Theodora; Wade, Kimberley A.; Stewart, Neil

2009-01-01

In their descriptions, eyewitnesses often refer to a culprit's distinctive facial features. However, in a police lineup, selecting the only member with the described distinctive feature is unfair to the suspect and provides the police with little further information. For fair and informative lineups, the distinctive feature should be either replicated across foils or concealed on the target. In the present experiments, replication produced more correct identifications in target-present lineup...

Defining poverty as distinctively human

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H.P.P. Lötter

2007-05-01

Full Text Available While it is relatively easy for most people to identify human beings suffering from poverty, it is rather more difficult to come to a proper understanding of poverty. In this article the author wants to deepen our understanding of poverty by interpreting the conventional definitions of poverty in a new light. The article starts with a defence of a claim that poverty is a concept uniquely applicable to humans. It then present a critical discussion of the distinction between absolute and relative poverty and it is then argued that a revision of this distinction can provide general standards applicable to humans everywhere.

The Biology of the Triatomine Bugs Native to South Central Texas and Assessment of the Risk They Pose for Autochthonous Chagas Disease Exposure.

Science.gov (United States)

Wozniak, Edward J; Lawrence, Gena; Gorchakov, Rodion; Alamgir, Hasanat; Dotson, Ellen; Sissel, Blake; Sarkar, Sahotra; Murray, Kristy O

2015-10-01

Triatomine bugs are a group of hematophagous arthropods that can serve as biological vectors for Trypanosoma cruzi , the etiological agent of American trypanosomiasis (Chagas disease). Because of differences in the biology and feeding habits among triatomine species, some are more likely than others to be involved in zoonotic and/or human-to-human transmission cycles of T. cruzi . In an attempt to assess the risk for Chagas disease exposure in south-central Texas, human habitations across Texas Health Service Region 8 (HSR 8) and surrounding counties were surveyed for triatomines to characterize the geographic distribution, species-specific biology, and T. cruzi -infection prevalence better. Between May 2010 and August 2013, a total of 545 triatomines representing all 5 known indigenous species (Triatoma gerstaeckeri, Triatoma indictiva, Triatoma lecticularia, Triatoma sanguisuga, and Triatoma protracta woodi) were collected from 59 sites across the region. Triatoma gerstaeckeri was the species most commonly found in domestic and peridomestic ecotopes across Texas HSR 8, representing over 80% of the triatomines collected. Adult T. gerstaeckeri exhibited a seasonal dispersal pattern that began in late April, peaked in mid-May, and then continued into August. On homes with available crevices in the exterior walls, adult T. gerstaeckeri were observed emerging from or entering these protective microhabitats, suggesting possible opportunistic colonization of some exterior walls compartments. Laboratory testing of triatomine hindgut contents for T. cruzi by PCR demonstrated the adult T. gerstaeckeri-infection prevalence across Texas HSR 8 to be 64%. Monitoring peridomestic adult T. gerstaeckeri over the seasonal dispersal peak demonstrated statistically significant increases in both their T. cruzi -infection prevalence (P < 0.01) and tendency to invade human dwellings (P < 0.01) in the later aspect of the emergence peak. In addition to the adult insects, variably sized

NSAID gastropathy and enteropathy: distinct pathogenesis likely necessitates distinct prevention strategies.

Science.gov (United States)

Wallace, John L

2012-01-01

The mechanisms underlying the ability of nonsteroidal anti-inflammatory drugs (NSAIDs) to cause ulceration in the stomach and proximal duodenum are well understood, and this injury can largely be prevented through suppression of gastric acid secretion (mainly with proton pump inhibitors). In contrast, the pathogenesis of small intestinal injury induced by NSAIDs is less well understood, involving more complex mechanisms than those in the stomach and proximal duodenum. There is clear evidence for important contributions to NSAID enteropathy of enteric bacteria, bile and enterohepatic recirculation of the NSAID. There is no evidence that suppression of gastric acid secretion will reduce the incidence or severity of NSAID enteropathy. Indeed, clinical data suggest little, if any, benefit. Animal studies suggest a significant exacerbation of NSAID enteropathy when proton pump inhibitors are co-administered with the NSAID. This worsening of damage appears to be linked to changes in the number and types of bacteria in the small intestine during proton pump inhibitor therapy. The distinct mechanisms of NSAID-induced injury in the stomach/proximal duodenum versus the more distal small intestine likely dictate distinct strategies for prevention. © 2011 The Author. British Journal of Pharmacology © 2011 The British Pharmacological Society.

Distinctive Dynamic Capabilities for New Business Creation

DEFF Research Database (Denmark)

Rosenø, Axel; Enkel, Ellen; Mezger, Florian

2013-01-01

This study examines the distinctive dynamic capabilities for new business creation in established companies. We argue that these are very different from those for managing incremental innovation within a company's core business. We also propose that such capabilities are needed in both slow...... and fast-paced industries, and that similarities exist across industries. Hence, the study contributes to dynamic capabilities literature by: 1) identifying the distinctive dynamic capabilities for new business creation; 2) shifting focus away from dynamic capabilities in environments characterised by high...... clock-speed and uncertainty towards considering dynamic capabilities for the purpose of developing new businesses, which also implies a high degree of uncertainty. Based on interviews with 33 companies, we identify distinctive dynamic capabilities for new business creation, find that dynamic...

Many-Objective Distinct Candidates Optimization using Differential Evolution

DEFF Research Database (Denmark)

Justesen, Peter; Ursem, Rasmus Kjær

2010-01-01

for each objective. The Many-Objective Distinct Candidates Optimization using Differential Evolution (MODCODE) algorithm takes a novel approach by focusing search using a user-defined number of subpopulations each returning a distinct optimal solution within the preferred region of interest. In this paper......, we present the novel MODCODE algorithm incorporating the ROD measure to measure and control candidate distinctiveness. MODCODE is tested against GDE3 on three real world centrifugal pump design problems supplied by Grundfos. Our algorithm outperforms GDE3 on all problems with respect to all...

Creating fair lineups for suspects with distinctive features.

Science.gov (United States)

Zarkadi, Theodora; Wade, Kimberley A; Stewart, Neil

2009-12-01

In their descriptions, eyewitnesses often refer to a culprit's distinctive facial features. However, in a police lineup, selecting the only member with the described distinctive feature is unfair to the suspect and provides the police with little further information. For fair and informative lineups, the distinctive feature should be either replicated across foils or concealed on the target. In the present experiments, replication produced more correct identifications in target-present lineups--without increasing the incorrect identification of foils in target-absent lineups--than did concealment. This pattern, and only this pattern, is predicted by the hybrid-similarity model of recognition.

Amnesia, rehearsal, and temporal distinctiveness models of recall.

Science.gov (United States)

Brown, Gordon D A; Della Sala, Sergio; Foster, Jonathan K; Vousden, Janet I

2007-04-01

Classical amnesia involves selective memory impairment for temporally distant items in free recall (impaired primacy) together with relative preservation of memory for recency items. This abnormal serial position curve is traditionally taken as evidence for a distinction between different memory processes, with amnesia being associated with selectively impaired long-term memory. However recent accounts of normal serial position curves have emphasized the importance of rehearsal processes in giving rise to primacy effects and have suggested that a single temporal distinctiveness mechanism can account for both primacy and recency effects when rehearsal is considered. Here we explore the pattern of strategic rehearsal in a patient with very severe amnesia. When the patient's rehearsal pattern is taken into account, a temporal distinctiveness model can account for the serial position curve in both amnesic and control free recall. The results are taken as consistent with temporal distinctiveness models of free recall, and they motivate an emphasis on rehearsal patterns in understanding amnesic deficits in free recall.

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...

Distribución geográfica del género Pimeliaphilus Trägårdh (Acari: Prostigmata asociados a triatominos (Hemiptera: Reduviidae

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Gerardo A. MARTI

2017-01-01

Full Text Available Se brinda un listado de especies del género Pimeliaphilus Trägårdh asociadas a diferentes especies de triatominos, con sus respectivas coordenadas geográficas de todo el continente americano. Se realizaron viajes de campo para incorporar nuevos registros a una recopilación bibliográfica. Se extiende la distribución geográfica de Pimeliaphilus triatomae Cunliffe, con dos registros para la provincia de Chaco (Argentina y se amplía el rango de hospedadores ya que se citan por primera vez asociados a Triatoma delpontei Romaña & Abalos.

Experimental infection of two South American reservoirs with four distinct strains of Trypanosoma cruzi

Science.gov (United States)

Roellig, Dawn M.; McMillan, Katherine; Ellis, Angela E.; Vandeberg, John L.; Champagne, Donald E.; Yabsley, Michael J.

2010-01-01

SUMMARY Trypanosoma cruzi (Tc), the causative agent of Chagas disease, is a diverse species with 2 primary genotypes, TcI and TcII, with TcII further subdivided into 5 subtypes (IIa–e). This study evaluated infection dynamics of 4 genetically and geographically diverse T. cruzi strains in 2 South American reservoirs, degus (Octodon degus) and grey short-tailed opossums (Monodelphis domestica). Based on prior suggestions of a genotype-host association, we hypothesized that degus (placental) would more readily become infected with TcII strains while short-tailed opossums (marsupial) would be a more competent reservoir for a TcI strain. Individuals (n = 3) of each species were intraperitoneally inoculated with T. cruzi trypomastigotes of TcIIa [North America (NA)-raccoon (Procyon lotor) origin], TcI [NA-Virginia opossum (Didelphis virginiana)], TcIIb [South America (SA)-human], TcIIe (SA-Triatoma infestans), or both TcI and TcIIa. Parasitaemias in experimentally infected degus peaked earlier (7–14 days post-inoculation (p.i.)) compared with short-tailed opossums (21–84 days p.i.). Additionally, peak parasitaemias were higher in degus; however, the duration of detectable parasitaemias for all strains, except TcIIa, was greater in short-tailed opossums. Infections established in both host species with all genotypes, except for TcIIa, which did not establish a detectable infection in short-tailed opossums. These results indicate that both South American reservoirs support infections with these isolates from North and South America; however, infection dynamics differed with host and parasite strain. PMID:20128943

Notas sinonímicas em Lepturini sul-americanos (Coleoptera, Cerambycidae, Lepturinae Synonymical notes on South American Lepturini (Coleoptera, Cerambycidae, Lepturinae

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Miguel A. Monné

2004-12-01

Full Text Available Novas sinonímias propostas: Strangalia flavocincta (Thomson, 1860 = Ophistomis tristis Melzer, 1922 syn. nov. = O. latifasciata Melzer, 1926 syn. nov.; Strangalia succincta (Redtenbacher, 1867 = O. auriflua Redtenbacher, 1867 syn. nov.; Strangalia melanura (Redtenbacher, 1867 = Euryptera dimidiata Redtenbacher, 1867 syn. nov.; Strangalia lyrata (Redtenbacher, 1867 = Ophistomis discophora Redtenbacher, 1867 syn. nov.; Strangalia fulvicornis (Bates, 1872 = Ophistomis variabilis Melzer, 1926 syn. nov. = O. flavovittata Melzer, 1926 syn. nov.; Strangalia melanophthisis (Berg, 1889 reval. = Euryptera melanura var. nigripennis Melzer, 1930 syn. nov.; Anastrangalia sanguinolenta (Linnaeus, 1761 (espécie introduzida na Argentina = Leptura bonaeriensis Burmeister, 1865 syn. nov.New synonyms proposed: Strangalia flavocincta (Thomson, 1860 = Ophistomis tristis Melzer, 1922 syn. nov. = O. latifasciata Melzer, 1926 syn. nov.; Strangalia succincta (Redtenbacher, 1867 = O. auriflua Redtenbacher, 1867 syn. nov.; Strangalia melanura (Redtenbacher, 1867 = Euryptera dimidiata Redtenbacher, 1867 syn. nov.; Strangalia lyrata (Redtenbacher, 1867 = Ophistomis discophora Redtenbacher, 1867 syn. nov.; Strangalia fulvicornis (Bates, 1872 = Ophistomis variabilis Melzer, 1926 syn. nov. = O. flavovittata Melzer, 1926 syn. nov.; Strangalia melanophthisis (Berg, 1889 reval. = Euryptera melanura var. nigripennis Melzer, 1930 syn. nov.; Anastrangalia sanguinolenta (Linnaeus, 1761 (species introduced in Argentina = Leptura bonaeriensis Burmeister, 1865 syn. nov.

Distinctiveness of Encoding and Memory for Learning Tasks.

Science.gov (United States)

Glover, John A.; And Others

1982-01-01

A distinctiveness of encoding hypothesis, as applied to the facilitative effects that higher order objectives have on readers' prose recall, was evaluated in three experiments. Results suggest that distinctiveness of encoding may offer a theoretical basis for the effects of adjunct aids as well as a guide to their construction. (Author/GK)

Intergroup Leadership Across Distinct Subgroups and Identities.

Science.gov (United States)

Rast, David E; Hogg, Michael A; van Knippenberg, Daan

2018-03-01

Resolving intergroup conflict is a significant and often arduous leadership challenge, yet existing theory and research rarely, if ever, discuss or examine this situation. Leaders confront a significant challenge when they provide leadership across deep divisions between distinct subgroups defined by self-contained identities-The challenge is to avoid provoking subgroup identity distinctiveness threat. Drawing on intergroup leadership theory, three studies were conducted to test the core hypothesis that, where identity threat exists, leaders promoting an intergroup relational identity will be better evaluated and are more effective than leaders promoting a collective identity; in the absence of threat, leaders promoting a collective identity will prevail. Studies 1 and 2 ( N = 170; N = 120) supported this general proposition. Study 3 ( N = 136) extended these findings, showing that leaders promoting an intergroup relational identity, but not a collective identity, improved intergroup attitudes when participants experienced an identity distinctiveness threat.

The effects of distinctiveness on memory and metamemory for face-name associations.

Science.gov (United States)

Watier, Nicholas; Collin, Charles

2012-01-01

We examined the influence of face and name distinctiveness on memory and metamemory for face-name associations. Four types of monitoring judgements were solicited during encoding and retrieval of face-name pairs that contained distinct or typical faces (Experiment 1) or names (Experiment 2). The beneficial effects of distinctiveness on associative memory were symmetrical between faces and names, such that relative to their typical counterparts, distinct faces enhanced memory for names, and distinct names enhanced memory for faces. These effects were also apparent in metamemory. Estimates of prospective and retrospective memory performance were greater for face-name associations that contained a distinct face or name compared with a typical face or name, regardless of whether the distinct item was a cue or target. Moreover, the predictive validity of prospective monitoring improved with name distinctiveness, whereas the predictive validity of retrospective monitoring improved with facial distinctiveness. Our results indicate that distinctiveness affects not only the strength of the association between a face and a name, but also the ability to monitor that association.

An Investigation on the Ecology of Triatoma vitticeps (Stal, 1859 and its Possible Role in the Transmission of Trypanosoma cruzi, in the Locality of Triunfo, Santa Maria Madalena Municipal District, State of Rio de Janeiro, Brazil

Directory of Open Access Journals (Sweden)

Gonçalves Teresa Cristina M

1998-01-01

Full Text Available From January 1989 to April 1995, 465 specimens of Triatoma vitticeps were collected in the locality of Triunfo, 2nd District of Santa Maria Madalena municipal district, State of Rio de Janeiro. The bugs were found indoors by local residents with predominance of adults. The flight activity was high in hot months when the incidence in the domicile also increased. Two hundred and two bugs (111 alive and 91 dead were examined for Trypanosoma cruzi infection. This was detected in 31 of the dead bugs (34% and 88 (79% of the live bugs examined. With a view to investigate the possible vertebrate hosts of the T. cruzi isolates, the blood of 122 mammals was examined through Giemsa-stained smears, hemocultures and xenodiagnosis. T. cruzi was detected in three specimens of Didelphis marsupialis and T. (M. theileri was detected in one specimen of Bos taurus. The parasites were isolated from triatomine feces, xenoculture and hemoculture. No evidence of human infection was detected in 58 inhabitants examined, as evaluated by indirect imunofluorescence technique using T. cruzi epimastigotes as antigens. These results show that T. vitticeps is still a sylvatic species although nymphs have been found inside the domicile. Thus, an epidemiological vigilance is necessary to know the behaviour of this species following the continuous modifications promoted by the presence of man.

A Novel Algorithm for the Generation of Distinct Kinematic Chain

Science.gov (United States)

Medapati, Sreenivasa Reddy; Kuchibhotla, Mallikarjuna Rao; Annambhotla, Balaji Srinivasa Rao

2016-07-01

Generation of distinct kinematic chains is an important topic in the design of mechanisms for various industrial applications i.e., robotic manipulator, tractor, crane etc. Many researchers have intently focused on this area and explained various processes of generating distinct kinematic chains which are laborious and complex. It is desirable to enumerate the kinematic chains systematically to know the inherent characteristics of a chain related to its structure so that all the distinct chains can be analyzed in depth, prior to the selection of a chain for a purpose. This paper proposes a novel and simple method with set of rules defined to eliminate isomorphic kinematic chains generating distinct kinematic chains. Also, this method simplifies the process of generating distinct kinematic chains even at higher levels i.e., 10-link, 11-link with single and multiple degree of freedom.

Chagas disease vector blood meal sources identified by protein mass spectrometry.

Directory of Open Access Journals (Sweden)

Judith I Keller

Full Text Available Chagas disease is a complex vector borne parasitic disease involving blood feeding Triatominae (Hemiptera: Reduviidae insects, also known as kissing bugs, and the vertebrates they feed on. This disease has tremendous impacts on millions of people and is a global health problem. The etiological agent of Chagas disease, Trypanosoma cruzi (Kinetoplastea: Trypanosomatida: Trypanosomatidae, is deposited on the mammalian host in the insect's feces during a blood meal, and enters the host's blood stream through mucous membranes or a break in the skin. Identifying the blood meal sources of triatomine vectors is critical in understanding Chagas disease transmission dynamics, can lead to identification of other vertebrates important in the transmission cycle, and aids management decisions. The latter is particularly important as there is little in the way of effective therapeutics for Chagas disease. Several techniques, mostly DNA-based, are available for blood meal identification. However, further methods are needed, particularly when sample conditions lead to low-quality DNA or to assess the risk of human cross-contamination. We demonstrate a proteomics-based approach, using liquid chromatography tandem mass spectrometry (LC-MS/MS to identify host-specific hemoglobin peptides for blood meal identification in mouse blood control samples and apply LC-MS/MS for the first time to Triatoma dimidiata insect vectors, tracing blood sources to species. In contrast to most proteins, hemoglobin, stabilized by iron, is incredibly stable even being preserved through geologic time. We compared blood stored with and without an anticoagulant and examined field-collected insect specimens stored in suboptimal conditions such as at room temperature for long periods of time. To our knowledge, this is the first study using LC-MS/MS on field-collected arthropod disease vectors to identify blood meal composition, and where blood meal identification was confirmed with more

Fermionic bound states in distinct kinklike backgrounds

Energy Technology Data Exchange (ETDEWEB)

Bazeia, D. [Universidade Federal da Paraiba, Departamento de Fisica, Joao Pessoa, Paraiba (Brazil); Mohammadi, A. [Universidade Federal de Campina Grande, Departamento de Fisica, Caixa Postal 10071, Campina Grande, Paraiba (Brazil)

2017-04-15

This work deals with fermions in the background of distinct localized structures in the two-dimensional spacetime. Although the structures have a similar topological character, which is responsible for the appearance of fractionally charged excitations, we want to investigate how the geometric deformations that appear in the localized structures contribute to the change in the physical properties of the fermionic bound states. We investigate the two-kink and compact kinklike backgrounds, and we consider two distinct boson-fermion interactions, one motivated by supersymmetry and the other described by the standard Yukawa coupling. (orig.)

Soroprevalência de infecção chagásica em área de Triatoma infestans após medidas de controle

Directory of Open Access Journals (Sweden)

Carvalho Maria Esther

2000-01-01

Full Text Available INTRODUÇÃO: Como parte de projeto que busca resgatar informações sobre sorologia da infecção chagásica no Estado de São Paulo durante a vigência das atividades oficiais de controle de vetores, foram selecionados dados relativos ao município de Taquarituba, região de Sorocaba, de importante passado chagásico. A despeito da campanha de combate instituída na década de 50, ainda persistiam aí populações de triatomíneos vetores intradomiciliares na década de 70. MÉTODOS: De amostras das populações de cinco localidades do Município de Taquarituba, Estado de São Paulo, foram analisados os dados de idade, sexo, tempo de moradia na casa que ocupavam e naturalidade. A possível relação entre idade e soropositividade foi investigada utilizando-se o cálculo de probitos. De 1974 e 1976, a prevalência da infecção chagásica foi estimada por meio de reação de imunofluorescência indireta (RIFI para a detecção de anticorpos anti-Trypanosoma cruzi. RESULTADOS: A proporção total de soropositivos foi de 13,6% (n = 2.784, sem diferença significativa entre os sexos (p = 0,538. Os naturais de Taquarituba contribuíram com 62,9% das amostras examinadas e 62,4% dos soropositivos (n = 380. Ausente em crianças de menos de 6 anos, a soropositividade aumentou de 2,7% no grupo etário de 6 a 9 anos para 30,3% no de 30 a 39 anos. Dentro desse intervalo encontrou-se, por meio do cálculo de probitos, associação positiva entre idade e soropositividade. CONCLUSÕES: Os resultados das provas sorológicas sugeriram haver associação entre as medidas contra Triatoma infestans e o declínio da transmissão da doença de Chagas durante os anos 60, seguido de ulterior controle. Sugere-se a realização de pesquisa para investigar a ocorrência de infecção congênita em população feminina com mais de 14 anos, sorologicamente positivas.

Assessing gene expression during pathogenesis: Use of qRT-PCR to follow toxin production in the entomopathogenic fungus Beauveria bassiana during infection and immune response of the insect host Triatoma infestans.

Science.gov (United States)

Lobo, Luciana S; Luz, Christian; Fernandes, Éverton K K; Juárez, M Patricia; Pedrini, Nicolás

2015-06-01

Entomopathogenic fungi secrete toxic secondary metabolites during the invasion of the insect hemocoel as part of the infection process. Although these compounds have been frequently mentioned as virulence factors, the roles of many of them remain poorly understood, including the question of whether they are expressed during the infection process. A major hurdle to this issue remains the low sensitivity of biochemical detection techniques (e.g., HPLC) within the complex samples that may contain trace quantities of fungal molecules inside the insect. In this study, quantitative reverse transcription real-time PCR (qRT-PCR) was used to measure the transcript levels within the insect fungal pathogen Beauveria bassiana, that encode for the synthetase enzymes of the secondary metabolites tenellin (BbtenS), beauvericin (BbbeaS) and bassianolide (BbbslS) during the infection of Triatoma infestans, a Chagas disease insect vector. Absolute quantification was performed at different time periods after insect treatment with various concentrations of propagules, either by immersing the insects in conidial suspensions or by injecting them with blastospores. Both BbtenS and BbbeaS were highly expressed in conidia-treated insects at days 3 and 12 post-treatment. In blastospore-injected insects, BbtenS and BbbeaS expression peaked at 24h post-injection and were also highly expressed in insect cadavers. The levels of BbbslS transcripts were much lower in all conditions tested. The expression patterns of insect genes encoding proteins that belong to the T. infestans humoral immune system were also evaluated with the same technique. This qPCR-based methodology can contribute to decifering the dynamics of entomopathogenic fungal infection at the molecular level. Copyright © 2015 Elsevier Inc. All rights reserved.

Grammar-Lexicon Distinction in a Neurocognitive Context

DEFF Research Database (Denmark)

Ishkhanyan, Byurakn

hypotheses and testing them through using various methods. The grammar-lexicon distinction and working memory are thus central topics of this thesis. The results suggest a potential for a successful integration of the two theories. The findings further provide evidence for Boye & Harder’s (2012......) understanding of the grammar-lexicon distinction, and for the involvement of working memory in language production, as the REF-model would predict. As a starting point for integrating the two theories, the present thesis gives directions for future research on the neurocognitive underpinning of language and its...... relation to working memory....

Distinctions, Affiliations, and Professional Knowledge in Financial Reform Commissions

DEFF Research Database (Denmark)

Seabrooke, Leonard; Tsingou, Eleni

the different stresses in reports with and without clear mandates, and the role of important members of the policy community in promoting particular reform ideas. The article finds that differences in ideas emerging from the financial reform expert groups reflect nested power relationships in the commissioning...... the reports. Fractal distinctions, such as between ‘behavior’ or ‘system’ as a reform focus, allow us to locate the object of regulation within expert groups, experts’ professional context, and the politics behind the commissioning of work. Analyzing fractal distinctions provides a useful way to understand...... of work, constituent audiences, and reform priorities among governing institutions, rather than distinct ‘European’ and ‘American’ ideas....

Revitalizing the “civic” and “ethnic” distinction

DEFF Research Database (Denmark)

Larsen, Christian Albrekt

2017-01-01

This article describes how contemporary publics think about the nation along Kohn’s classic distinction between “civic” and “ethnic” nationalism. The article makes three contributes to the existing literature. Firstly, it introduces a new statistical tool, multi-classification-analysis, to establ......This article describes how contemporary publics think about the nation along Kohn’s classic distinction between “civic” and “ethnic” nationalism. The article makes three contributes to the existing literature. Firstly, it introduces a new statistical tool, multi...

29 CFR 549.3 - Distinction between plan and trust.

Science.gov (United States)

2010-07-01

... 29 Labor 3 2010-07-01 2010-07-01 false Distinction between plan and trust. 549.3 Section 549.3 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR REGULATIONS REQUIREMENTS OF A âBONA FIDE PROFIT-SHARING PLAN OR TRUSTâ § 549.3 Distinction between plan and trust. As used in this part: (a) Profit-sharing plan...

Atlas of Mexican Triatominae (Reduviidae: Hemiptera) and vector transmission of Chagas disease

Science.gov (United States)

Ramsey, Janine M; Peterson, A Townsend; Carmona-Castro, Oscar; Moo-Llanes, David A; Nakazawa, Yoshinori; Butrick, Morgan; Tun-Ku, Ezequiel; de la Cruz-Félix, Keynes; Ibarra-Cerdeña, Carlos N

2015-01-01

Chagas disease is one of the most important yet neglected parasitic diseases in Mexico and is transmitted by Triatominae. Nineteen of the 31 Mexican triatomine species have been consistently found to invade human houses and all have been found to be naturally infected with Trypanosoma cruzi. The present paper aims to produce a state-of-knowledge atlas of Mexican triatomines and analyse their geographic associations with T. cruzi, human demographics and landscape modification. Ecological niche models (ENMs) were constructed for the 19 species with more than 10 records in North America, as well as for T. cruzi. The 2010 Mexican national census and the 2007 National Forestry Inventory were used to analyse overlap patterns with ENMs. Niche breadth was greatest in species from the semiarid Nearctic Region, whereas species richness was associated with topographic heterogeneity in the Neotropical Region, particularly along the Pacific Coast. Three species, Triatoma longipennis, Triatoma mexicana and Triatoma barberi, overlapped with the greatest numbers of human communities, but these communities had the lowest rural/urban population ratios. Triatomine vectors have urbanised in most regions, demonstrating a high tolerance to human-modified habitats and broadened historical ranges, exposing more than 88% of the Mexican population and leaving few areas in Mexico without the potential for T. cruzi transmission. PMID:25993505

Atlas of Mexican Triatominae (Reduviidae: Hemiptera and vector transmission of Chagas disease

Directory of Open Access Journals (Sweden)

Janine M Ramsey

2015-05-01

Full Text Available Chagas disease is one of the most important yet neglected parasitic diseases in Mexico and is transmitted by Triatominae. Nineteen of the 31 Mexican triatomine species have been consistently found to invade human houses and all have been found to be naturally infected with Trypanosoma cruzi. The present paper aims to produce a state-of-knowledge atlas of Mexican triatomines and analyse their geographic associations with T. cruzi, human demographics and landscape modification. Ecological niche models (ENMs were constructed for the 19 species with more than 10 records in North America, as well as for T. cruzi. The 2010 Mexican national census and the 2007 National Forestry Inventory were used to analyse overlap patterns with ENMs. Niche breadth was greatest in species from the semiarid Nearctic Region, whereas species richness was associated with topographic heterogeneity in the Neotropical Region, particularly along the Pacific Coast. Three species, Triatoma longipennis, Triatoma mexicana and Triatoma barberi, overlapped with the greatest numbers of human communities, but these communities had the lowest rural/urban population ratios. Triatomine vectors have urbanised in most regions, demonstrating a high tolerance to human-modified habitats and broadened historical ranges, exposing more than 88% of the Mexican population and leaving few areas in Mexico without the potential for T. cruzi transmission.

Genetic Determinism and the Innate-Acquired Distinction in Medicine

Science.gov (United States)

2009-01-01

This article illustrates in which sense genetic determinism is still part of the contemporary interactionist consensus in medicine. Three dimensions of this consensus are discussed: kinds of causes, a continuum of traits ranging from monogenetic diseases to car accidents, and different kinds of determination due to different norms of reaction. On this basis, this article explicates in which sense the interactionist consensus presupposes the innate–acquired distinction. After a descriptive Part 1, Part 2 reviews why the innate–acquired distinction is under attack in contemporary philosophy of biology. Three arguments are then presented to provide a limited and pragmatic defense of the distinction: an epistemic, a conceptual, and a historical argument. If interpreted in a certain manner, and if the pragmatic goals of prevention and treatment (ideally specifying what medicine and health care is all about) are taken into account, then the innate–acquired distinction can be a useful epistemic tool. It can help, first, to understand that genetic determination does not mean fatalism, and, second, to maintain a system of checks and balances in the continuing nature–nurture debates. PMID:20234831

Contesting the science/ethics distinction in the review of clinical research

Science.gov (United States)

Dawson, Angus J; Yentis, Steve M

2007-01-01

Recent policy in relation to clinical research proposals in the UK has distinguished between two types of review: scientific and ethical. This distinction has been formally enshrined in the recent changes to research ethics committee (REC) structure and operating procedures, introduced as the UK response to the EU Directive on clinical trials. Recent reviews and recommendations have confirmed the place of the distinction and the separate review processes. However, serious reservations can be mounted about the science/ethics distinction and the policy of separate review that has been built upon it. We argue here that, first, the science/ethics distinction is incoherent, and, second, that RECs should not only be permitted to consider a study's science, but that they have anobligation do so. PMID:17329389

Validity of Sensory Systems as Distinct Constructs

OpenAIRE

Su, Chia-Ting; Parham, L. Diane

2014-01-01

Confirmatory factor analysis testing whether sensory questionnaire items represented distinct sensory system constructs found, using data from two age groups, that such constructs can be measured validly using questionnaire data.

Identity-specific motivation: How distinct identities direct self-regulation across distinct situations.

Science.gov (United States)

Browman, Alexander S; Destin, Mesmin; Molden, Daniel C

2017-12-01

Research on self-regulation has traditionally emphasized that people's thoughts and actions are guided by either (a) domain-general motivations that emerge from a cumulative history of life experiences, or (b) situation-specific motivations that emerge in immediate response to the incentives present in a particular context. However, more recent studies have illustrated the importance of understanding the interplay between such domain-general and situation-specific motivations across the types of contexts people regularly encounter. The present research, therefore, expands existing perspectives on self-regulation by investigating how people's identities -the internalized roles, relationships, and social group memberships that define who they are-systemically guide when and how different domain-general motivations are activated within specific types of situations. Using the motivational framework described by regulatory focus theory (Higgins, 1997), Studies 1 and 2 demonstrate that people indeed have distinct, identity-specific motivations that uniquely influence their current self-regulation when such identities are active. Studies 3-5 then begin to explore how identity-specific motivations are situated within people's larger self-concept. Studies 3a and 3b demonstrate that the less compatible people's specific identities, the more distinct are the motivations connected to those identities. Studies 4-5 then provide some initial, suggestive evidence that identity-specific motivations are not a separate, superordinate feature of people's identities that then alter how they pursue any subordinate, identity-relevant traits, but instead that such motivations emerge from the cumulative motivational significance of the subordinate traits to which the identities themselves become attached. Implications for understanding the role of the self-concept in self-regulation are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Agent-specific learning signals for self-other distinction during mentalising.

Directory of Open Access Journals (Sweden)

Sam Ereira

2018-04-01

Full Text Available Humans have a remarkable ability to simulate the minds of others. How the brain distinguishes between mental states attributed to self and mental states attributed to someone else is unknown. Here, we investigated how fundamental neural learning signals are selectively attributed to different agents. Specifically, we asked whether learning signals are encoded in agent-specific neural patterns or whether a self-other distinction depends on encoding agent identity separately from this learning signal. To examine this, we tasked subjects to learn continuously 2 models of the same environment, such that one was selectively attributed to self and the other was selectively attributed to another agent. Combining computational modelling with magnetoencephalography (MEG enabled us to track neural representations of prediction errors (PEs and beliefs attributed to self, and of simulated PEs and beliefs attributed to another agent. We found that the representational pattern of a PE reliably predicts the identity of the agent to whom the signal is attributed, consistent with a neural self-other distinction implemented via agent-specific learning signals. Strikingly, subjects exhibiting a weaker neural self-other distinction also had a reduced behavioural capacity for self-other distinction and displayed more marked subclinical psychopathological traits. The neural self-other distinction was also modulated by social context, evidenced in a significantly reduced decoding of agent identity in a nonsocial control task. Thus, we show that self-other distinction is realised through an encoding of agent identity intrinsic to fundamental learning signals. The observation that the fidelity of this encoding predicts psychopathological traits is of interest as a potential neurocomputational psychiatric biomarker.

Embarrassment: its distinct form and appeasement functions.

Science.gov (United States)

Keltner, D; Buswell, B N

1997-11-01

The authors address 2 questions about embarrassment. First, Is embarrassment a distinct emotion? The evidence indicates that the antecedents, experience, and display of embarrassment, and to a limited extent its autonomic physiology, are distinct from shame, guilt, and amusement and share the dynamic, temporal characteristics of emotion. Second, What are the theoretical accounts of embarrassment? Three accounts focus on the causes of embarrassment, positioning that it follows the loss of self-esteem, concern for others' evaluations, or absence of scripts to guide interactions. A fourth account focuses on the effects of the remedial actions of embarrassment, which correct preceding transgressions. A fifth account focuses on the functional parallels between embarrassment and nonhuman appeasement. The discussion focuses on unanswered questions about embarrassment.

Culture and the distinctiveness motive: constructing identity in individualistic and collectivistic contexts.

Science.gov (United States)

Becker, Maja; Vignoles, Vivian L; Owe, Ellinor; Brown, Rupert; Smith, Peter B; Easterbrook, Matt; Herman, Ginette; de Sauvage, Isabelle; Bourguignon, David; Torres, Ana; Camino, Leoncio; Lemos, Flávia Cristina Silveira; Ferreira, M Cristina; Koller, Silvia H; González, Roberto; Carrasco, Diego; Cadena, Maria Paz; Lay, Siugmin; Wang, Qian; Bond, Michael Harris; Trujillo, Elvia Vargas; Balanta, Paola; Valk, Aune; Mekonnen, Kassahun Habtamu; Nizharadze, George; Fülöp, Marta; Regalia, Camillo; Manzi, Claudia; Brambilla, Maria; Harb, Charles; Aldhafri, Said; Martin, Mariana; Macapagal, Ma Elizabeth J; Chybicka, Aneta; Gavreliuc, Alin; Buitendach, Johanna; Gallo, Inge Schweiger; Ozgen, Emre; Güner, Ulkü E; Yamakoğlu, Nil

2012-04-01

The motive to attain a distinctive identity is sometimes thought to be stronger in, or even specific to, those socialized into individualistic cultures. Using data from 4,751 participants in 21 cultural groups (18 nations and 3 regions), we tested this prediction against our alternative view that culture would moderate the ways in which people achieve feelings of distinctiveness, rather than influence the strength of their motivation to do so. We measured the distinctiveness motive using an indirect technique to avoid cultural response biases. Analyses showed that the distinctiveness motive was not weaker-and, if anything, was stronger-in more collectivistic nations. However, individualism-collectivism was found to moderate the ways in which feelings of distinctiveness were constructed: Distinctiveness was associated more closely with difference and separateness in more individualistic cultures and was associated more closely with social position in more collectivistic cultures. Multilevel analysis confirmed that it is the prevailing beliefs and values in an individual's context, rather than the individual's own beliefs and values, that account for these differences. (c) 2012 APA, all rights reserved.

Impact of repeated ivermectin treatments against onchocerciasis on the transmission of loiasis: an entomologic evaluation in central Cameroon.

Science.gov (United States)

Kouam, Marc K; Tchatchueng-Mbougua, Jules B; Demanou, Maurice; Boussinesq, Michel; Pion, Sébastien D S; Kamgno, Joseph

2013-09-27

Annual community-directed treatment with ivermectin (CDTI) have been carried out since 1999 in the Lekie division (central region of Cameroon where most cases of Loa-related post ivermectin severe adverse events were reported) as part of the joined activities of the African Programme for Onchocerciasis Control (APOC) and Mectizan® Donation Program (MDP). As large-scale administration of ivermetine was demonstrated to be an efficient means to control loiasis transmission, it was hypothesized that CDTI would have lowered or halted the transmission of Loa loa in the Lekie division after 13 years of annual drug administration, indicating a possible reduction in the occurrence of Loa-related post-ivermectin severe adverse events. A 4-month entomologic study was carried out from March to June 2012 in the Lekie division to evaluate the impact of 13 years of CDTI on the transmission of L. loa whose baseline data were recorded in 1999-2000. There was a significant reduction in the infection rate for Chrysops silacea and C. dimidiata from 6.8 and 9% in 1999-2000 to 3 and 3.6% in 2012, respectively. The differences in the infective rate (IR) (percentage of flies harboring head L3 larvae), potential infective rate (PIR) (percentage of flies bearing L3 larvae), mean head L3 larvae load (MHL3) (average L3 per infective fly) and mean fly L3 larvae load (MFL3) (average L3 per potentially infective fly) for both C. silacea and C. dimidiata were not significantly different between the two investigation periods. The biting density (BD) was almost three-fold higher in 2012 for C. silacea but not for C. dimidiata. The transmission potential (TP) which is a function of the BD, was higher in the present study than in the baseline investigation for each species. The infection rate remaining high, the high TP and the stability observed in the IR, PIR, MHL3 and MFL3 after 13 years of CDTI suggest that transmission of L. loa is still active. This is an indication that the risk of occurrence

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

Knowledge Affords Distinctive Processing in Memory

Science.gov (United States)

Hunt, R. Reed; Rawson, Katherine A.

2011-01-01

The effect of knowledge on memory generally is processing. However, both conceptual and empirical reasons exist to suspect that the organizational account is incomplete. Recently a revised version of that account has been proposed under the rubric of distinctiveness theory (Rawson & Van Overschelde, 2008). The goal of the experiments reported…

El subgénero Trigona S. Str. Jurine 1808 (Hymenoptera: Apidae: Meliponinae) en Colombia

OpenAIRE

Édgar Javier Hernández Martínez; Guiomar Nates Parra

2004-01-01

Para Colombia se registran 28 de los 29 taxones descritos para el subgénero Trigona s. str. T. (T.) albipennis Almeida, 1992; T. (T.) amalthea Olivier, 1789; T. (T.) hyalinata var. amazonensis Ducke, 1916; T. (T.) hyalinata var. branneri Cockerell, 1912; T. (T.) chanchamayoënsis Schwarz, 1948; T. (T.) cilipes Fabricius, 1804; T. (T.) corvina Cockerell, 1913; T. (T.) crassipes Fabricius, 1793; T. (T.) dallatorreana Friese, 1900; T. (T.) dimidiata var. venezuelana Schwarz, 1948; T. (T.) dimi...

El subgénero Trigona S. Str. Jurine 1808 (Hymenoptera: Apidae: Meliponinae) en Colombia

OpenAIRE

Hernández Martínez Édgar Javier; Nates Parra Guiomar

2004-01-01

Para Colombia se registran 28 de los 29 taxones descritos para el subgénero Trigona s. str. T. (T.) albipennis Almeida, 1992; T. (T.) amalthea Olivier, 1789; T. (T.) hyalinata var. amazonensis
Ducke, 1916; T. (T.) hyalinata var. branneri Cockerell, 1912; T. (T.) chanchamayoënsis Schwarz, 1948; T. (T.) cilipes Fabricius, 1804; T. (T.) corvina Cockerell, 1913; T. (T.) crassipes Fabricius, 1793; T. (T.) dallatorreana Friese, 1900; T. (T.) dimidiata var. venezuelana Schwarz, 1948; T. (...

Distinctions, Affiliations, and Professional Knowledge in Financial Reform Expert Groups

DEFF Research Database (Denmark)

Seabrooke, Leonard; Tsingou, Eleni

2014-01-01

to understand the different stresses in reports with and without clear mandates, and the role of important members of the policy community in promoting particular reform ideas. The contribution finds that differences in ideas emerging from the financial reform expert groups reflect nested power relationships...... the reports. Fractal distinctions, such as between ‘behaviour’ or ‘system’ as a reform focus, allow us to locate the object of regulation within expert groups, the experts' professional context and the politics behind the commissioning of work. Analysing fractal distinctions provides a useful way...... in the commissioning of work, constituent audiences and reform priorities among governing institutions, rather than distinct ‘European’ and ‘American’ ideas....

Liquidity spillover in international stock markets through distinct time scales.

Science.gov (United States)

Righi, Marcelo Brutti; Vieira, Kelmara Mendes

2014-01-01

This paper identifies liquidity spillovers through different time scales based on a wavelet multiscaling method. We decompose daily data from U.S., British, Brazilian and Hong Kong stock markets indices in order to calculate the scale correlation between their illiquidities. The sample is divided in order to consider non-crisis, sub-prime crisis and Eurozone crisis. We find that there are changes in correlations of distinct scales and different periods. Association in finest scales is smaller than in coarse scales. There is a rise on associations in periods of crisis. In frequencies, there is predominance for significant distinctions involving the coarsest scale, while for crises periods there is predominance for distinctions on the finest scale.

Distinctiveness of Saudi Arabian EFL Learners

Science.gov (United States)

Habbash, Manssour; Idapalapati, Srinivasa Rao

2016-01-01

In view of the increasing concern among English language teachers dealing with students from Saudi Arabia, as it manifests in TESOL community discussions, about the uniqueness of Saudi Arabian EFL learners, this paper attempts to document the outcome of a study of their distinctiveness from the perspective of expatriate teachers working for PYPs…

Temporal Variation in the Abundance and Timing of Daily Activity of Chagas Disease Vector Triatoma gerstaeckeri (Stål, 1859) in a Natural Habitat in the Lower Rio Grande Valley, South Texas.

Science.gov (United States)

Flores, A; Vitek, C; Feria-Arroyo, T P; Fredensborg, B L

2017-10-01

Chagas disease caused by Trypanosoma cruzi is a burden to millions of people in South and Central America. A sylvatic life cycle of the parasite exists in the Southern United States, but recent studies indicate an active peri-domestic life cycle of T. cruzi in Texas. The United States-Mexico border region in Texas displays areas of high poverty and sub-standard housing conditions which are important risk factors for a potential spill-over transmission to a domestic life cycle including humans. The objectives of the study were to examine short- and long-term temporal variation in vector activity and to evaluate the effect of different combinations of attractants on the capture of potential triatomine vectors. We collected local triatomine vectors (all of them identified as Triatoma gerstaeckeri) from a natural habitat in South Texas during the course of a year. The exact time of collection was recorded to examine the timing of flight activity of the triatomine vector. We also conducted a comparative study of the efficiency of 2 commonly used attractants (light and CO 2 ) and the combination of those on the capture rate of Tr. gerstaeckeri. Our study indicates a short season of dispersal of Tr. gerstaeckeri (April/May) and it suggests a unimodal distribution of activity peaking between 2 and 3 hr after sunset. Ultra-violet light served as the main attractant of Tr. gerstaeckeri while CO 2 from dry ice did not significantly contribute to the collection of vectors. The pronounced timing of activity in Tr. gerstaeckeri reported in this study contributes to our understanding of the epidemiology of T. cruzi in wildlife and its potential as a Chagas disease vector to humans in the Rio Grande Valley, South Texas.

Neural correlates of the food/non-food visual distinction.

Science.gov (United States)

Tsourides, Kleovoulos; Shariat, Shahriar; Nejati, Hossein; Gandhi, Tapan K; Cardinaux, Annie; Simons, Christopher T; Cheung, Ngai-Man; Pavlovic, Vladimir; Sinha, Pawan

2016-03-01

An evolutionarily ancient skill we possess is the ability to distinguish between food and non-food. Our goal here is to identify the neural correlates of visually driven 'edible-inedible' perceptual distinction. We also investigate correlates of the finer-grained likability assessment. Our stimuli depicted food or non-food items with sub-classes of appealing or unappealing exemplars. Using data-classification techniques drawn from machine-learning, as well as evoked-response analyses, we sought to determine whether these four classes of stimuli could be distinguished based on the patterns of brain activity they elicited. Subjects viewed 200 images while in a MEG scanner. Our analyses yielded two successes and a surprising failure. The food/non-food distinction had a robust neural counterpart and emerged as early as 85 ms post-stimulus onset. The likable/non-likable distinction too was evident in the neural signals when food and non-food stimuli were grouped together, or when only the non-food stimuli were included in the analyses. However, we were unable to identify any neural correlates of this distinction when limiting the analyses only to food stimuli. Taken together, these positive and negative results further our understanding of the substrates of a set of ecologically important judgments and have clinical implications for conditions like eating-disorders and anhedonia. Copyright © 2016 Elsevier B.V. All rights reserved.

MAGDM linear-programming models with distinct uncertain preference structures.

Science.gov (United States)

Xu, Zeshui S; Chen, Jian

2008-10-01

Group decision making with preference information on alternatives is an interesting and important research topic which has been receiving more and more attention in recent years. The purpose of this paper is to investigate multiple-attribute group decision-making (MAGDM) problems with distinct uncertain preference structures. We develop some linear-programming models for dealing with the MAGDM problems, where the information about attribute weights is incomplete, and the decision makers have their preferences on alternatives. The provided preference information can be represented in the following three distinct uncertain preference structures: 1) interval utility values; 2) interval fuzzy preference relations; and 3) interval multiplicative preference relations. We first establish some linear-programming models based on decision matrix and each of the distinct uncertain preference structures and, then, develop some linear-programming models to integrate all three structures of subjective uncertain preference information provided by the decision makers and the objective information depicted in the decision matrix. Furthermore, we propose a simple and straightforward approach in ranking and selecting the given alternatives. It is worth pointing out that the developed models can also be used to deal with the situations where the three distinct uncertain preference structures are reduced to the traditional ones, i.e., utility values, fuzzy preference relations, and multiplicative preference relations. Finally, we use a practical example to illustrate in detail the calculation process of the developed approach.

The death of distinctions: From 9/11 to Abu Ghraib.

Science.gov (United States)

Moon, John Ellis van Courtland

2004-09-01

War, the great simplifier, is the inevitable enemy of distinctions, especially when conflicts evoke survival fears, sounding echoes from humanity's environment of evolutionary adaptation. Throughout the twentieth century, attackers and targets grew more distant, weaponry grew more destructive, and distinctions -- between combatants and civilians, between legitimate and protected targets, between defensive and offensive strategies, between the innocent and the guilty -- faded. In the twenty-first century's first major conflict, "the war against terror," distinctions have faded still further, making nearly indistinguishable the frontier between preemption and prevention and between interrogation and torture. Proclaimed a "new type of war" in which old rules and customary safeguards would often be inapplicable, this conflict quickly came to be characterized by political embarrassment and operational scandal.

The physician-administrator as patient: distinctive aspects of medical care.

Science.gov (United States)

Cappell, Mitchell S

2011-01-01

This article examines distinctive aspects of medical care experienced by a 55-year-old hospitalized for quintuple coronary artery bypass surgery who was also a senior physician-administrator (chief of gastroenterology) at the same hospital. The article describes eight distinctive aspects of administrator-physicians as patients, including special patient treatment; exalted patient expectations by hospital personnel; patient suppression of emotions; patient denial; self-doctoring; job stress contributing to disease; self-sacrifice to achieve better health; and rational medical decisions when not under stress. Health-care workers should recognize how these distinctive aspects of medical care and behavior affect administrator-physicians as patients, in order to mitigate their negative effects, potentiate their positive effects, and optimize the care of these patients.

Place preference and vocal learning rely on distinct reinforcers in songbirds.

Science.gov (United States)

Murdoch, Don; Chen, Ruidong; Goldberg, Jesse H

2018-04-30

In reinforcement learning (RL) agents are typically tasked with maximizing a single objective function such as reward. But it remains poorly understood how agents might pursue distinct objectives at once. In machines, multiobjective RL can be achieved by dividing a single agent into multiple sub-agents, each of which is shaped by agent-specific reinforcement, but it remains unknown if animals adopt this strategy. Here we use songbirds to test if navigation and singing, two behaviors with distinct objectives, can be differentially reinforced. We demonstrate that strobe flashes aversively condition place preference but not song syllables. Brief noise bursts aversively condition song syllables but positively reinforce place preference. Thus distinct behavior-generating systems, or agencies, within a single animal can be shaped by correspondingly distinct reinforcement signals. Our findings suggest that spatially segregated vocal circuits can solve a credit assignment problem associated with multiobjective learning.

False memories in children and adults: age, distinctiveness, and subjective experience.

Science.gov (United States)

Ghetti, Simona; Qin, Jianjian; Goodman, Gail S

2002-09-01

This study investigated developmental trends associated with the Deese/Roediger-McDermott false-memory effect, the role of distinctive information in false-memory formation, and participants' subjective experience of true and false memories. Children (5- and 7-year-olds) and adults studied lists of semantically associated words. Half of the participants studied words alone, and half studied words accompanied by pictures. There were significant age differences in recall (5-year-olds evinced more false memories than did adults) but not in recognition of critical lures. Distinctive information reduced false memory for all age groups. Younger children provided with distinctive information, and older children and adults regardless of whether they viewed distinctive information, expressed higher levels of confidence in true than in false memories. Source attributions did not significantly differ between true and false memories. Implications for theories of false memory and memory development are discussed.

The picture superiority effect in conceptual implicit memory: a conceptual distinctiveness hypothesis.

Science.gov (United States)

Hamilton, Maryellen; Geraci, Lisa

2006-01-01

According to leading theories, the picture superiority effect is driven by conceptual processing, yet this effect has been difficult to obtain using conceptual implicit memory tests. We hypothesized that the picture superiority effect results from conceptual processing of a picture's distinctive features rather than a picture's semantic features. To test this hypothesis, we used 2 conceptual implicit general knowledge tests; one cued conceptually distinctive features (e.g., "What animal has large eyes?") and the other cued semantic features (e.g., "What animal is the figurehead of Tootsie Roll?"). Results showed a picture superiority effect only on the conceptual test using distinctive cues, supporting our hypothesis that this effect is mediated by conceptual processing of a picture's distinctive features.

An Adult Developmental Approach to Perceived Facial Attractiveness and Distinctiveness

Directory of Open Access Journals (Sweden)

Natalie C. Ebner

2018-05-01

Full Text Available Attractiveness and distinctiveness constitute facial features with high biological and social relevance. Bringing a developmental perspective to research on social-cognitive face perception, we used a large set of faces taken from the FACES Lifespan Database to examine effects of face and perceiver characteristics on subjective evaluations of attractiveness and distinctiveness in young (20–31 years, middle-aged (44–55 years, and older (70–81 years men and women. We report novel findings supporting variations by face and perceiver age, in interaction with gender and emotion: although older and middle-aged compared to young perceivers generally rated faces of all ages as more attractive, young perceivers gave relatively higher attractiveness ratings to young compared to middle-aged and older faces. Controlling for variations in attractiveness, older compared to young faces were viewed as more distinctive by young and middle-aged perceivers. Age affected attractiveness more negatively for female than male faces. Furthermore, happy faces were rated as most attractive, while disgusted faces were rated as least attractive, particularly so by middle-aged and older perceivers and for young and female faces. Perceivers largely agreed on distinctiveness ratings for neutral and happy emotions, but older and middle-aged compared to young perceivers rated faces displaying negative emotions as more distinctive. These findings underscore the importance of a lifespan perspective on perception of facial characteristics and suggest possible effects of age on goal-directed perception, social motivation, and in-group bias. This publication makes available picture-specific normative data for experimental stimulus selection.

[The control of vectorial transmission].

Science.gov (United States)

Silveira, Antônio Carlos; Dias, João Carlos Pinto

2011-01-01

Between 1950 and 1951, the first Prophylactic campaign against Chagas Diseases was carried on in Brazil by the so existing Serviço Nacional de Malária. The actions involving chemical vector control comprehended 74 municipalities along the Rio Grande Valley, between the States of São Paulo and Minas Gerais. Ever since, until 1975, the activities were performed according the availability of resources, being executed with more or less regularity and coverage. At that time, Chagas disease did no represent priority, in comparison with other endemic diseases prevalent in the Country. Even so, taking into account the accumulated data along those 25 years, the volume of work realized cannot be considered despicable. Nevertheless, it was few consistent, in terms of its impact on disease transmission. In 1975, with an additional injection of resources surpassed from the malaria program, plus the methodological systematization of the activities, and with the results of two extensive national inquiries (entomologic and serologic), the activities for vector control could be performed regularly, following two basic principles: interventions in always contiguous areas, progressively enlarged, and sustainability (continuity) of the activities, until being attained determined requirements and purpose previously established. Such actions and strategies lead into the exhaustion of the populations of the principal vector species, Triatoma infestans, no autochthonous and exclusively domiciliary, as well as the control of the domiciliary colonization of autochthonous species important to disease transmission. Vector transmission today is being considered residual, by means of some few native and peridomestic species, such as Triatoma brasiliensis and Triatoma pseudomaculata. There is, also, the risk of progressive domiciliation of some species before considered sylvatic, such as Panstrongylus lutzi and Triatoma rubrovaria. Finally, there is the possibility of the occurrence of cases

False Memories in Children and Adults: Age, Distinctiveness, and Subjective Experience.

Science.gov (United States)

Ghetti, Simona; Qin, Jianjian; Goodman, Gail S.

2002-01-01

Investigated developmental trends associated with the Deese/Roediger-McDermott false-memory effect, the role of distinctive information, and subjective experience of true/false memories. Found that 5-year-olds recalled more false memories than adults but no age differences in recognition of critical lures. Distinctive information reduced false…

Natural Microbial Assemblages Reflect Distinct Organismal and Functional Partitioning

Science.gov (United States)

Wilmes, P.; Andersson, A.; Kalnejais, L. H.; Verberkmoes, N. C.; Lefsrud, M. G.; Wexler, M.; Singer, S. W.; Shah, M.; Bond, P. L.; Thelen, M. P.; Hettich, R. L.; Banfield, J. F.

2007-12-01

The ability to link microbial community structure to function has long been a primary focus of environmental microbiology. With the advent of community genomic and proteomic techniques, along with advances in microscopic imaging techniques, it is now possible to gain insights into the organismal and functional makeup of microbial communities. Biofilms growing within highly acidic solutions inside the Richmond Mine (Iron Mountain, Redding, California) exhibit distinct macro- and microscopic morphologies. They are composed of microorganisms belonging to the three domains of life, including archaea, bacteria and eukarya. The proportion of each organismal type depends on sampling location and developmental stage. For example, mature biofilms floating on top of acid mine drainage (AMD) pools exhibit layers consisting of a densely packed bottom layer of the chemoautolithotroph Leptospirillum group II, a less dense top layer composed mainly of archaea, and fungal filaments spanning across the entire biofilm. The expression of cytochrome 579 (the most highly abundant protein in the biofilm, believed to be central to iron oxidation and encoded by Leptospirillum group II) is localized at the interface of the biofilm with the AMD solution, highlighting that biofilm architecture is reflected at the functional gene expression level. Distinct functional partitioning is also apparent in a biological wastewater treatment system that selects for distinct polyphosphate accumulating organisms. Community genomic data from " Candidatus Accumulibacter phosphatis" dominated activated sludge has enabled high mass-accuracy shotgun proteomics for identification of key metabolic pathways. Comprehensive genome-wide alignment of orthologous proteins suggests distinct partitioning of protein variants involved in both core-metabolism and specific metabolic pathways among the dominant population and closely related species. In addition, strain- resolved proteogenomic analysis of the AMD biofilms

An Objective Approach to Identify Spectral Distinctiveness for Hearing Impairment

Directory of Open Access Journals (Sweden)

Yeou-Jiunn Chen

2013-01-01

Full Text Available To facilitate the process of developing speech perception, speech-language pathologists have to teach a subject with hearing loss the differences between two syllables by manually enhancing acoustic cues of speech. However, this process is time consuming and difficult. Thus, this study proposes an objective approach to automatically identify the regions of spectral distinctiveness between two syllables, which is used for speech-perception training. To accurately represent the characteristics of speech, mel-frequency cepstrum coefficients are selected as analytical parameters. The mismatch between two syllables in time domain is handled by dynamic time warping. Further, a filter bank is adopted to estimate the components in different frequency bands, which are also represented as mel-frequency cepstrum coefficients. The spectral distinctiveness in different frequency bands is then easily estimated by using Euclidean metrics. Finally, a morphological gradient operator is applied to automatically identify the regions of spectral distinctiveness. To evaluate the proposed approach, the identified regions are manipulated and then the manipulated syllables are measured by a close-set based speech-perception test. The experimental results demonstrated that the identified regions of spectral distinctiveness are very useful in speech perception, which indeed can help speech-language pathologists in speech-perception training.

Common and distinct components in data fusion

DEFF Research Database (Denmark)

Smilde, Age Klaas; Mage, Ingrid; Næs, Tormod

2016-01-01

and understanding their relative merits. This paper provides a unifying framework for this subfield of data fusion by using rigorous arguments from linear algebra. The most frequently used methods for distinguishing common and distinct components are explained in this framework and some practical examples are given...

Distinctiveness enhances long-term event memory in non-human primates, irrespective of reinforcement.

Science.gov (United States)

Lewis, Amy; Call, Josep; Berntsen, Dorthe

2017-08-01

Non-human primates are capable of recalling events that occurred as long as 3 years ago, and are able to distinguish between similar events; akin to human memory. In humans, distinctiveness enhances memory for events, however, it is unknown whether the same occurs in non-human primates. As such, we tested three great ape species on their ability to remember an event that varied in distinctiveness. Across three experiments, apes witnessed a baiting event in which one of three identical containers was baited with food. After a delay of 2 weeks, we tested their memory for the location of the baited container. Apes failed to recall the baited container when the event was undistinctive (Experiment 1), but were successful when it was distinctive (Experiment 2), although performance was equally good in a less-distinctive condition. A third experiment (Experiment 3) confirmed that distinctiveness, independent of reinforcement, was a consistent predictor of performance. These findings suggest that distinctiveness may enhance memory for events in non-human primates in the same way as in humans, and provides further evidence of basic similarities between the ways apes and humans remember past events. © 2017 Wiley Periodicals, Inc.

Distinct types of eigenvector localization in networks

Science.gov (United States)

Pastor-Satorras, Romualdo; Castellano, Claudio

2016-01-01

The spectral properties of the adjacency matrix provide a trove of information about the structure and function of complex networks. In particular, the largest eigenvalue and its associated principal eigenvector are crucial in the understanding of nodes’ centrality and the unfolding of dynamical processes. Here we show that two distinct types of localization of the principal eigenvector may occur in heterogeneous networks. For synthetic networks with degree distribution P(q) ~ q-γ, localization occurs on the largest hub if γ > 5/2 for γ < 5/2 a new type of localization arises on a mesoscopic subgraph associated with the shell with the largest index in the K-core decomposition. Similar evidence for the existence of distinct localization modes is found in the analysis of real-world networks. Our results open a new perspective on dynamical processes on networks and on a recently proposed alternative measure of node centrality based on the non-backtracking matrix.

Presidential address: distinction or extinction.

Science.gov (United States)

Pressman, Barry D

2008-10-01

Despite its continuing scientific successes in imaging, radiology as a specialty is faced with a very difficult and competitive environment. Nonradiologists are more and more interested in vertically integrating imaging into their practices, while teleradiology and picture archiving and communication systems are resulting in the greater isolation of radiologists. Commoditization is a realistic and devastating threat to the survival and professionalism of the specialty. To remain viable as a specialty, radiologists must elevate their practice by subspecializing, becoming more involved with clinical care, and actively interacting with patients and referring clinicians. Distinction will prevent extinction.

Moral fiction or moral fact? The distinction between doing and allowing in medical ethics.

Science.gov (United States)

Huddle, Thomas S

2013-06-01

Opponents of physician-assisted suicide (PAS) maintain that physician withdrawal-of-life-sustaining-treatment cannot be morally equated to voluntary active euthanasia. PAS opponents generally distinguish these two kinds of act by positing a possible moral distinction between killing and allowing-to-die, ceteris paribus. While that distinction continues to be widely accepted in the public discourse, it has been more controversial among philosophers. Some ethicist PAS advocates are so certain that the distinction is invalid that they describe PAS opponents who hold to the distinction as in the grip of 'moral fictions'. The author contends that such a diagnosis is too hasty. The possibility of a moral distinction between active euthanasia and allowing-to-die has not been closed off by the argumentative strategies employed by these PAS advocates, including the contrasting cases strategy and the assimilation of doing and allowing to a common sense notion of causation. The philosophical debate over the doing/allowing distinction remains inconclusive, but physicians and others who rely upon that distinction in thinking about the ethics of end-of-life care need not give up on it in response to these arguments. © 2012 John Wiley & Sons Ltd.

Directed networks' different link formation mechanisms causing degree distribution distinction

Science.gov (United States)

Behfar, Stefan Kambiz; Turkina, Ekaterina; Cohendet, Patrick; Burger-Helmchen, Thierry

2016-11-01

Within undirected networks, scientists have shown much interest in presenting power-law features. For instance, Barabási and Albert (1999) claimed that a common property of many large networks is that vertex connectivity follows scale-free power-law distribution, and in another study Barabási et al. (2002) showed power law evolution in the social network of scientific collaboration. At the same time, Jiang et al. (2011) discussed deviation from power-law distribution; others indicated that size effect (Bagrow et al., 2008), information filtering mechanism (Mossa et al., 2002), and birth and death process (Shi et al., 2005) could account for this deviation. Within directed networks, many authors have considered that outlinks follow a similar mechanism of creation as inlinks' (Faloutsos et al., 1999; Krapivsky et al., 2001; Tanimoto, 2009) with link creation rate being the linear function of node degree, resulting in a power-law shape for both indegree and outdegree distribution. Some other authors have made an assumption that directed networks, such as scientific collaboration or citation, behave as undirected, resulting in a power-law degree distribution accordingly (Barabási et al., 2002). At the same time, we claim (1) Outlinks feature different degree distributions than inlinks; where different link formation mechanisms cause the distribution distinctions, (2) in/outdegree distribution distinction holds for different levels of system decomposition; therefore this distribution distinction is a property of directed networks. First, we emphasize in/outlink formation mechanisms as causal factors for distinction between indegree and outdegree distributions (where this distinction has already been noticed in Barker et al. (2010) and Baxter et al. (2006)) within a sample network of OSS projects as well as Java software corpus as a network. Second, we analyze whether this distribution distinction holds for different levels of system decomposition: open

An Adult Developmental Approach to Perceived Facial Attractiveness and Distinctiveness

OpenAIRE

Natalie C. Ebner; Natalie C. Ebner; Natalie C. Ebner; Joerg Luedicke; Manuel C. Voelkle; Manuel C. Voelkle; Michaela Riediger; Michaela Riediger; Tian Lin; Ulman Lindenberger; Ulman Lindenberger

2018-01-01

Attractiveness and distinctiveness constitute facial features with high biological and social relevance. Bringing a developmental perspective to research on social-cognitive face perception, we used a large set of faces taken from the FACES Lifespan Database to examine effects of face and perceiver characteristics on subjective evaluations of attractiveness and distinctiveness in young (20–31 years), middle-aged (44–55 years), and older (70–81 years) men and women. We report novel findings su...

Tagging like Humans: Diverse and Distinct Image Annotation

KAUST Repository

Wu, Baoyuan; Chen, Weidong; Sun, Peng; Liu, Wei; Ghanem, Bernard; Lyu, Siwei

2018-01-01

including quantitative and qualitative comparisons, as well as human subject studies, on two benchmark datasets demonstrate that the proposed model can produce more diverse and distinct tags than the state-of-the-arts.

Evidence and characterization of a glide-vowel distinction in American English

Directory of Open Access Journals (Sweden)

Zachary Scott Jaggers

2018-02-01

Full Text Available This study tests whether native speakers of American English exhibit a glide-vowel distinction ([j]-[i] in a speech elicitation experiment. When reading sentences out loud, participants’ pronunciations of 4 near-minimal pairs of pre-existing lexical items (e.g., 'Eston'[iə] vs. 'pneumon'[jə] exhibit significant differences when acoustically measured, confirming the presence of a [j]-[i] distinction. This distinction is also found to be productively extended to the production of 20 near-minimal pairs of nonce words (e.g., 'Súmia '→ [sumiə] vs. 'Fímya '→ [fimjə], diversified and balanced along different phonologically relevant factors of the surrounding environment. Multiple acoustic measurements are compared to test what aspects most consistently convey the distinction: F2 (frontness, F1 (height, intensity, vocalic sequence duration, transition earliness, and transition speed. This serves the purpose of documenting the distinction’s acoustic phonetic realization. It also serves in the comparison of phonological representations. Multiple types of previously proposed phonological representations are considered along with the competing predictions they generate regarding the acoustic measurements performed. Results suggest that the primary and most consistent characteristic of the distinction is earliness of transition into the following vowel, with results also suggesting that the [j] glide has a greater degree of constriction. The [j] glide is found to have a significantly 'less 'anterior articulation, challenging the application of a representation based on place or articulator differences that would predict [j] to be 'more 'anterior.

Distinctive skeletal dysplasia in Cockayne syndrome

International Nuclear Information System (INIS)

Silengo, M.C.; Franceschini, P.; Bianco, R.; Biagioli, M.; Pastorin, L.; Vista, N.; Baldassar, A.; Benso, L.

1986-01-01

Cockayne syndrom is a well-known autosomal recessive form of dwarfism with senile-like appearance. Skeletal changes such as flattening of vertebral bodies, ivory epiphyses and thickening of cranial vault, have been observed in some patients with this condition. We describe here a 5.5-year-old girl with the typical clinical signs of Cockayne syndrome and a distinctive form of bone dysplasia with major involvment of the spine. (orig.)

Distinctive skeletal dysplasia in Cockayne syndrome

Energy Technology Data Exchange (ETDEWEB)

Silengo, M.C.; Franceschini, P.; Bianco, R.; Biagioli, M.; Pastorin, L.; Vista, N.; Baldassar, A.; Benso, L.

1986-03-01

Cockayne syndrome is a well-known autosomal recessive form of dwarfism with senile-like appearance. Skeletal changes such as flattening of vertebral bodies, ivory epiphyses and thickening of cranial vault, have been observed in some patients with this condition. We describe here a 5.5-year-old girl with the typical clinical signs of Cockayne syndrome and a distinctive form of bone dysplasia with major involvement of the spine.

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

The usefulness of the grammaticality-acceptability distinction in functional approaches to language

DEFF Research Database (Denmark)

Poulsen, Mads

2013-01-01

between competence and performance, rather than on a distinction between syntax and meaning. The basic rationale for having such a distinction is that much of linguistics is concerned with describing relatively stable grammatical knowledge, rather than the psycholinguistic dynamics of language use...

Genetically Distinct Subsets within ANCA-Associated Vasculitis

Science.gov (United States)

Lyons, Paul A.; Rayner, Tim F.; Trivedi, Sapna; Holle, Julia U.; Watts, Richard A.; Jayne, David R.W.; Baslund, Bo; Brenchley, Paul; Bruchfeld, Annette; Chaudhry, Afzal N.; Tervaert, Jan Willem Cohen; Deloukas, Panos; Feighery, Conleth; Gross, Wolfgang L.; Guillevin, Loic; Gunnarsson, Iva; P, Lorraine Harper M.R.C; Hrušková, Zdenka; Little, Mark A.; Martorana, Davide; Neumann, Thomas; Ohlsson, Sophie; Padmanabhan, Sandosh; Pusey, Charles D.; Salama, Alan D.; Sanders, Jan-Stephan F.; Savage, Caroline O.; Segelmark, Mårten; Stegeman, Coen A.; Tesař, Vladimir; Vaglio, Augusto; Wieczorek, Stefan; Wilde, Benjamin; Zwerina, Jochen; Rees, Andrew J.; Clayton, David G.; Smith, Kenneth G.C.

2013-01-01

BACKGROUND Antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis is a severe condition encompassing two major syndromes: granulomatosis with polyangiitis (formerly known as Wegener’s granulomatosis) and microscopic polyangiitis. Its cause is unknown, and there is debate about whether it is a single disease entity and what role ANCA plays in its pathogenesis. We investigated its genetic basis. METHODS A genomewide association study was performed in a discovery cohort of 1233 U.K. patients with ANCA-associated vasculitis and 5884 controls and was replicated in 1454 Northern European case patients and 1666 controls. Quality control, population stratification, and statistical analyses were performed according to standard criteria. RESULTS We found both major-histocompatibility-complex (MHC) and non-MHC associations with ANCA-associated vasculitis and also that granulomatosis with polyangiitis and microscopic polyangiitis were genetically distinct. The strongest genetic associations were with the antigenic specificity of ANCA, not with the clinical syndrome. Anti–proteinase 3 ANCA was associated with HLA-DP and the genes encoding α1-antitrypsin (SERPINA1) and proteinase 3 (PRTN3) (P = 6.2×10−89, P = 5.6×10−12, and P = 2.6×10−7, respectively). Anti–myeloperoxidase ANCA was associated with HLA-DQ (P = 2.1×10−8). CONCLUSIONS This study confirms that the pathogenesis of ANCA-associated vasculitis has a genetic component, shows genetic distinctions between granulomatosis with polyangiitis and microscopic polyangiitis that are associated with ANCA specificity, and suggests that the response against the autoantigen proteinase 3 is a central pathogenic feature of proteinase 3 ANCA–associated vasculitis. These data provide preliminary support for the concept that proteinase 3 ANCA–associated vasculitis and myeloperoxidase ANCA–associated vasculitis are distinct autoimmune syndromes. (Funded by the British Heart Foundation and others.) PMID

Participation and social participation: are they distinct concepts?

Science.gov (United States)

Piškur, Barbara; Daniëls, Ramon; Jongmans, Marian J; Ketelaar, Marjolijn; Smeets, Rob J E M; Norton, Meghan; Beurskens, Anna J H M

2014-03-01

The concept of participation has been extensively used in health and social care literature since the World Health Organization introduced its description in the International Classification of Functioning, Disability and Health (ICF) in 2001. More recently, the concept of social participation is frequently used in research articles and policy reports. However, in the ICF, no specific definition exists for social participation, and an explanation of differences between the concepts is not available. The central question in this discussion article is whether participation, as defined by the ICF, and social participation are distinct concepts. This article illustrates the concepts of participation and social participation, presents a critical discussion of their definitions, followed by implications for rehabilitation and possible future directions. A clear definition for participation or social participation does not yet exist. Definitions for social participation differ from each other and are not sufficiently distinct from the ICF definition of participation. Although the ICF is regarded an important conceptual framework, it is criticised for not being comprehensive. The relevance of societal involvement of clients is evident for rehabilitation, but the current ICF definition of participation does not sufficiently capture societal involvement. Changing the ICF's definition of participation towards social roles would overcome a number of its shortcomings. Societal involvement would then be understood in the light of social roles. Consequently, there would be no need to make a distinction between social participation and participation.

Processing vertical size disparities in distinct depth planes.

Science.gov (United States)

Duke, Philip A; Howard, Ian P

2012-08-17

A textured surface appears slanted about a vertical axis when the image in one eye is horizontally enlarged relative to the image in the other eye. The surface appears slanted in the opposite direction when the same image is vertically enlarged. Two superimposed textured surfaces with different horizontal size disparities appear as two surfaces that differ in slant. Superimposed textured surfaces with equal and opposite vertical size disparities appear as a single frontal surface. The vertical disparities are averaged. We investigated whether vertical size disparities are averaged across two superimposed textured surfaces in different depth planes or whether they induce distinct slants in the two depth planes. In Experiment 1, two superimposed textured surfaces with different vertical size disparities were presented in two depth planes defined by horizontal disparity. The surfaces induced distinct slants when the horizontal disparity was more than ±5 arcmin. Thus, vertical size disparities are not averaged over surfaces with different horizontal disparities. In Experiment 2 we confirmed that vertical size disparities are processed in surfaces away from the horopter, so the results of Experiment 1 cannot be explained by the processing of vertical size disparities in a fixated surface only. Together, these results show that vertical size disparities are processed separately in distinct depth planes. The results also suggest that vertical size disparities are not used to register slant globally by their effect on the registration of binocular direction of gaze.

Pseudomonas aeruginosa diversity in distinct paediatric patient groups

DEFF Research Database (Denmark)

Tramper-Stranders, G.A.; Ent, C.K. van der; Wolfs, T.F.

2008-01-01

the other groups. A group of clonal isolates was observed among patients from the CF-chronic and CF-1 groups. These or different clonal isolates were not encountered among the three other patient groups. No characteristic resistance pattern could be identified among isolates from the distinct patient groups......Pseudomonas aeruginosa is a pathogen that often infects patients who are either immunocompromised or have local defects in host defences. It is known that cystic fibrosis (CF) patients are sometimes infected with certain clonal isolates. It is not clear whether these clonal isolates also infect non......-CF patients and whether clonality of isolates occurs in other patient groups. The aim of this study was to investigate P. aeruginosa diversity and the occurrence of clones within five distinct paediatric patient groups susceptible to P. aeruginosa infection. P. aeruginosa isolates were cultured from 157...

European freshwater VHSV genotype Ia isolates divide into two distinct subpopulations

DEFF Research Database (Denmark)

Kahns, Søren; Skall, Helle Frank; Kaas, Rolf Sommer

2012-01-01

Viral haemorrhagic septicaemia (VHS), caused by the novirhabdovirus VHSV, often leads to significant economic losses to European rainbow trout production. The virus isolates are divided into 4 distinct genotypes with additional subgroups including sublineage Ia, isolates of which are the main...... detected in Denmark since January 2009. Full-length G-genes of all Danish VHSV isolates that were submitted for diagnostic analyses in the period 2004−2009 were sequenced and analysed. All 58 Danish isolates from rainbow trout grouped with sublineage Ia isolates. Furthermore, VHSV isolates from infected...... Danish freshwater catchments appear to have evolved into a distinct clade within sublineage Ia, herein designated clade Ia-1, whereas trout isolates originating from other continental European countries cluster in another distinct clade, designated clade Ia-2. In addition, phylogenetic analyses indicate...

Confluence for classical logic through the distinction between values and computations

Directory of Open Access Journals (Sweden)

José Espírito Santo

2014-09-01

Full Text Available We apply an idea originated in the theory of programming languages - monadic meta-language with a distinction between values and computations - in the design of a calculus of cut-elimination for classical logic. The cut-elimination calculus we obtain comprehends the call-by-name and call-by-value fragments of Curien-Herbelin's lambda-bar-mu-mu-tilde-calculus without losing confluence, and is based on a distinction of "modes" in the proof expressions and "mode" annotations in types. Modes resemble colors and polarities, but are quite different: we give meaning to them in terms of a monadic meta-language where the distinction between values and computations is fully explored. This meta-language is a refinement of the classical monadic language previously introduced by the authors, and is also developed in the paper.

Unsentimental Ethics: Towards a Content-Specific Account of the Moral-Conventional Distinction

Science.gov (United States)

Royzman, Edward B.; Leeman, Robert F.; Baron, Jonathan

2009-01-01

In this paper, we offer an overview and a critique of the existing theories of the moral-conventional distinction, with emphasis on Nichols's [Nichols, S. (2002). Norms with feeling: Towards a psychological account of moral judgment. "Cognition, 84", 221-236] neo-sentimentalist approach. After discussing some distinctive features of Nichols's…

Number of perceptually distinct surface colors in natural scenes.

Science.gov (United States)

Marín-Franch, Iván; Foster, David H

2010-09-30

The ability to perceptually identify distinct surfaces in natural scenes by virtue of their color depends not only on the relative frequency of surface colors but also on the probabilistic nature of observer judgments. Previous methods of estimating the number of discriminable surface colors, whether based on theoretical color gamuts or recorded from real scenes, have taken a deterministic approach. Thus, a three-dimensional representation of the gamut of colors is divided into elementary cells or points which are spaced at one discrimination-threshold unit intervals and which are then counted. In this study, information-theoretic methods were used to take into account both differing surface-color frequencies and observer response uncertainty. Spectral radiances were calculated from 50 hyperspectral images of natural scenes and were represented in a perceptually almost uniform color space. The average number of perceptually distinct surface colors was estimated as 7.3 × 10(3), much smaller than that based on counting methods. This number is also much smaller than the number of distinct points in a scene that are, in principle, available for reliable identification under illuminant changes, suggesting that color constancy, or the lack of it, does not generally determine the limit on the use of color for surface identification.

Distinct Evening Fatigue Profiles in Oncology Outpatients Receiving Chemotherapy

Science.gov (United States)

Wright, Fay; Cooper, Bruce A.; Conley, Yvette P.; Hammer, Marilyn J.; Chen, Lee-May; Paul, Steven M.; Levine, Jon D.; Miaskowski, Christine; Kober, Kord M.

2018-01-01

Background Fatigue is the most common and debilitating symptom experienced by oncology patients during chemotherapy (CTX). Fatigue severity demonstrates a large amount of inter-individual and diurnal variability. Purpose Study purposes were to evaluate for subgroups of patients with distinct evening fatigue profiles and evaluate how these subgroups differed on demographic, clinical, and symptom characteristics. Methods Outpatients with breast, gastrointestinal, gynecological, or lung cancer (n=1332) completed questionnaires six times over two cycles of CTX. Lee Fatigue Scale (LFS) evaluated evening fatigue severity. Latent profile analysis was used to identify distinct evening fatigue profiles. Results Four distinct evening fatigue classes (i.e., Low (14.0%), Moderate (17.2%), High (36.0%), Very High (32.8%)) were identified. Compared to the Low class, patients in the Very High evening fatigue class were: younger, female, had childcare responsibilities, had more years of education, had a lower functional status, had a higher comorbidity burden, and were diagnosed with breast cancer. Patients in the Very High class reported higher levels of depressive symptoms, sleep disturbance, and evening fatigue at enrollment. Conclusions Findings provide new insights into modifiable risk factors for higher levels of evening fatigue. Clinicians can use this information to identify higher risk patients and plan appropriate interventions. PMID:29725554

Organism versus mechanism: Losing our grip on the distinction

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Henk Reitsema

2013-11-01

Full Text Available The distinction between organism and mechanism is often subtle or unclear and yet can prove to be fundamental to our understanding of the world. It has been tempting for many thinkers to seek to ‘understand’ all of reality through the lens of either the one or the other of these concepts rather than by giving both a place. This article sets out to argue that there is a substantial loss of understanding when either of these metaphors is absolutised to explain all causal processes and patterns in reality. Clarifying the distinction between the two may provide one more tool to grasp what is reductionist in many of the perspectives that have come to dominate public life and science today. This contention is tested on the quest for the design of self-replicating systems (i.e. synthetic organisms in the nanotech industry. It is common that the concepts of organic functioning and mechanism are used imprecisely and in an overlapping way. This is also true of much scientific debate, especially in the fields of biology, micro-biology and nano-science. This imprecise use signals a reductionist tendency both in the way that the organic is perceived and in terms of the distinctive nature of mechanisms.

Dissociative effects of orthographic distinctiveness in pure and mixed lists: an item-order account.

Science.gov (United States)

McDaniel, Mark A; Cahill, Michael; Bugg, Julie M; Meadow, Nathaniel G

2011-10-01

We apply the item-order theory of list composition effects in free recall to the orthographic distinctiveness effect. The item-order account assumes that orthographically distinct items advantage item-specific encoding in both mixed and pure lists, but at the expense of exploiting relational information present in the list. Experiment 1 replicated the typical free recall advantage of orthographically distinct items in mixed lists and the elimination of that advantage in pure lists. Supporting the item-order account, recognition performances indicated that orthographically distinct items received greater item-specific encoding than did orthographically common items in mixed and pure lists (Experiments 1 and 2). Furthermore, order memory (input-output correspondence and sequential contiguity effects) was evident in recall of pure unstructured common lists, but not in recall of unstructured distinct lists (Experiment 1). These combined patterns, although not anticipated by prevailing views, are consistent with an item-order account.

A doença de Chagas no Paraná Chagas disease in the state of Paraná

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H. C. de Souza-Araujo

1954-06-01

Full Text Available In recent speech in Curitiba (May 22nd, 1954, Dr. Mario Pinotti, Director, Serviço Nacional da Malaria, informed that his personnel started on February, 1953, a survey upon chagas Disease in 23 counties of the State of Paraná, South Brazil. out of 895 places surveyed, 678, or 75.7%, were infected by Triatoma infestans klug 1834 and in 234 out of those 678, or 34.5%, this vector was infected by Trypanosoma cruzi. The general natural infection of the insects examined reached 18.86%. The serological survey (Machado-Guerreiro test was positive in 10.7% of the persons examined in jacarezinho and in 28.3% of those living in Bôa Vista. These data suggested the author to actualise the subject. During his control of severe outbreack of malaria in the North part of Paraná, from march to June 1917 he worked in 8 counties. March 1917 he photographed in Boa Vista four girls, severe cases of chronic malaria, two of which showed bi-palpebral oedema, later on considered by Dr. Pinho Simões (1943 as Romanã syndrome (created in 1935 and Prof. Salvador Mazza (1946 classified as typical cases of Chagas' Disease. now, being elapsed 36 years, the National Service of Malaria confirmed the discovery. The region surveyed was populated, in the beginning of this century, by immigrants from the State of Minas Gerais, from where the author believes that were imported the disease and its vectors. In April 1917 the A. discovered that the old town Jatahy was a big focus of Triatoma megista (now Panstrongylus megistus0. All its 43 houses were strongly infested by such hematophagus and amongst the 200 inhabitants seen many were suspicious cases of chronic cases of Chagas's Disease. In the Indians town (three tribes of S. Pedro D' Alcantara, situated in front of Jatahy, in the left side of the river Tibagy, there were no Triatomas nor suspicious cases of trypanosomiasis. In 1919 the author started the control of the endemics by destroying the foci of Triatomas and reforming

76 FR 14883 - Endangered and Threatened Species; Proposed Threatened Status for Distinct Population Segments of...

Science.gov (United States)

2011-03-18

...-XZ58 Endangered and Threatened Species; Proposed Threatened Status for Distinct Population Segments of..., published a proposed rule to list the Beringia and Okhotsk Distinct Population Segments (DPSs) of the... published a proposed rule to list the Beringia and Okhotsk Distinct Population Segments (DPSs) of the...

The theory–practice distinction and the complexity of practical knowledge

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Bonnie Miller-McLemore

2016-08-01

Full Text Available Over the past few decades, theologians have recognised the value of practice but have been optimistic about the ease with which practice is incorporated into theology. People use all sorts of adjectives to characterise the complex relationship – ‘integrally related’, a ‘deeper reciprocity’, ‘bound up in thickly intertwined ways’ – but connecting the two is not as easy as these words suggest. This article returns to the age-old question about the relationship between theory and practice. But it studies this question from the angle of practice. Although many scholars have analysed the distinction between theory and practice as it functions conceptually, few have examined challenges in relating the two as they emerge in practice. The article argues that there is an inevitable distinction between theory and practice that receives considerably less attention and needs more understanding and even respect. It also argues that the discipline of practical theology adds a distinctive angle on this discussion because it considers how the concepts function practically.

Ecologia domestica de la tripanosomiasis americana: perfil alimentario del triatoma infestans en un area rural de la província de Santiago del Estero, Argentina

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Cristina Wisnivesky-Colli

1987-03-01

Full Text Available Se describen los resultados entomológicos de un estúdio sobre transmiswn del Tripanosoma cruzi realizado en un caserío rural de Argentina. Se determino la prevalencia de infección elperfil alimentario de los Triatoma infestans domiciliados, relacionándose su densidad con el tipo de vivienda. Seis de las 18 viviendas estudiadas eran nuevas o mejoradas y en 16 los habitantes aplicaban hexaclorociclohexano. La menor densidad de vinchucas correspondió a las casas higiénicas o mejoradas con tratamiento químico, Los ranchos tratados presentaron un número de insectos 10 veces menor que un rancho no tratado, indicando la efectividad del control autogestado. Se hallaron T. infestans en el 100% de los dormitorios pero en sólo el 53% de los localesperidomiciliarios. Un 39% de las vinchucas intradomiciliarias estaban infectadas. El 96% de los insectos de dormitorios se alimentaron sobre hombre, perro, polloygato, siendo el índice afinidad para el perro 13 veces superior al correspondiente al hombre. Se discute la importancia epidemiológica de la concentración de vectores dentro de los dormitorios y su asociación trófica con los perros convivientes, nsí como la necessidad de combinar la mejora de vivienda con educación sanitaria.Entomological aspects of an ecological study on domestic T. cruzi transmission carried out in a rural community of Argentina are described. T. cruzi infection rates an d the feeding profiles of domiciliary T. infestans were determined, and bug density was related to house construction. Six of 18 houses studied were new and reformed while 16 households hexachlorocyclohexane (HCH had been used by the inmates. The lowest bug densities were found in new houses or those receiving good, insecticide treatment. Insecticide treated units had an a verage number of bugs 10 times lower(3.1 bugs/man-hour than thosefound in a non treated ones indicating the effectiveness of selfp romoted control. A ll bedrooms but only 53% o f

Magnetic mirror fusion systems: Characteristics and distinctive features

International Nuclear Information System (INIS)

Post, R.F.

1987-01-01

A tutorial account is given of the main characteristics and distinctive features of conceptual magnetic fusion systems employing the magnetic mirror principle. These features are related to the potential advantages that mirror-based fusion systems may exhibit for the generation of economic fusion power

Mapping Phylogenetic Trees to Reveal Distinct Patterns of Evolution.

Science.gov (United States)

Kendall, Michelle; Colijn, Caroline

2016-10-01

Evolutionary relationships are frequently described by phylogenetic trees, but a central barrier in many fields is the difficulty of interpreting data containing conflicting phylogenetic signals. We present a metric-based method for comparing trees which extracts distinct alternative evolutionary relationships embedded in data. We demonstrate detection and resolution of phylogenetic uncertainty in a recent study of anole lizards, leading to alternate hypotheses about their evolutionary relationships. We use our approach to compare trees derived from different genes of Ebolavirus and find that the VP30 gene has a distinct phylogenetic signature composed of three alternatives that differ in the deep branching structure. phylogenetics, evolution, tree metrics, genetics, sequencing. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Substantial Union or Substantial Distinction of Mind and Body in Descartes' Metaphysics

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Fahime Jamei

2009-01-01

Full Text Available According to Descartes’ metaphysics there are two different kinds of substances in the world of creatures: “thinking substance” and “extended substance” or soul and matter. In Descartes’ philosophy the soul is equal to the mind and considered as a “thinking substance”. This immaterial substance is the essence of the human being. Body, being considered as a “matter“, is an “extended substance” and entirely distinct from the soul. The soul, therefore, exists and may be known prior to body and, not being corporeal, can exist after human death. Hence, Descartes can prove the immortality of human soul in the framework of the principle of substantial distinction. On the other hand, as a physiologist and psychologist, Descartes indeed believes in mind-body union, so that some causal interactions between mind and body show their substantial union. In this essay, the authors show that Descartes faces a serious problem in combining substantial union of mind and body with their substantial distinction; despite of his efforts in introducing the idea of pineal gland, the problem remains unsolved. Therefore it seems that as he cannot dispense with his only reason for proving the immortality of human soul, he has to hold the mind-body distinction theory in his metaphysics. Indeed, Descartes prefers to support the distinction theory rather than union theory in confronting a thesis and an antithesis stating one of two theories

Substantial :union: or Substantial Distinction of Mind and Body in Descartes\\' Metaphysics

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f Jamei

2009-06-01

Full Text Available According to Descartes’ metaphysics there are two different kinds of substances in the world of creatures: “thinking substance” and “extended substance” or soul and matter. In Descartes’ philosophy the soul is equal to the mind and considered as a “thinking substance”. This immaterial substance is the essence of the human being. Body, being considered as a “matter“, is an “extended substance” and entirely distinct from the soul. The soul, therefore, exists and may be known prior to body and, not being corporeal, can exist after human death. Hence, Descartes can prove the immortality of human soul in the framework of the principle of substantial distinction. On the other hand, as a physiologist and psychologist, Descartes indeed believes in mind-body :union:, so that some causal interactions between mind and body show their substantial :union:. In this essay, the authors show that Descartes faces a serious problem in combining substantial :union: of mind and body with their substantial distinction despite of his efforts in introducing the idea of pineal gland, the problem remains unsolved. Therefore it seems that as he cannot dispense with his only reason for proving the immortality of human soul, he has to hold the mind-body distinction theory in his metaphysics. Indeed, Descartes prefers to support the distinction theory rather than :union: theory in confronting a thesis and an antithesis stating one of two theories.

Morphological distinctiveness of Javan Tupaia hypochrysa (Scandentia, Tupaiidae)

Science.gov (United States)

Sargis, Eric J.; Woodman, Neal; Morningstar, Natalie C.; Reese, Aspen T.; Olson, Link E.

2013-01-01

The common treeshrew, Tupaia glis, represents a species complex with a complicated taxonomic history. It is distributed mostly south of the Isthmus of Kra on the Malay Peninsula and surrounding islands. In our recent revision of a portion of this species complex, we did not fully assess the population from Java (T. “glis” hypochrysa) because of our limited sample. Herein, we revisit this taxon using multivariate analyses in comparisons with T. glis, T. chrysogaster of the Mentawai Islands, and T. ferruginea from Sumatra. Analyses of both the manus and skull of Javan T. “glis” hypochrysa show it to be most similar to T. chrysogaster and distinct from both T. glis and T. ferruginea. Yet, the Javan population and T. chrysogaster have different mammae counts, supporting recognition of T. hypochrysa as a distinct species. The change in taxonomic status of T. hypochrysa has conservation implications for both T. glis and this Javan endemic.

Mistakes To Avoid In Attacking The Moral/Conventional Distinction

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Alejandro Rosas

2012-11-01

Full Text Available In an experimental critique of the moral/conventional (M/C distinction, Kelly et al. (2007 present new experimental data about responses to transgressions involving harm, where the novelty is that transgressors are grown-ups, rather than children. Their data do not support the moral/conventional distinction. The contrast between grown-up and schoolyard transgressions does not seem, however, to explain their results: they also use two schoolyard transgressions with similar negative results for the M/C distinction.I here attempt to explain away their results by calling attention to two mistakes in their experimental design. One refers to the use of questionnaire-items of the type that Turiel and collaborators have called mixed-domain situations, which extend over both a moral and a conventional domain. Participants respond to these cases differently than to prototypical moral situations, because some allow the authority rule to override the moral rule. The second mistake emerges in the grown-up transgressions labeled as Whipping/temporal, Whipping/Authority, Spanking/Authority, Prisoner abuse/Authority. These are not the typical transgressions unambiguously “involving a victim who has been harmed, whose rights have been violated, or who has been subject to an injustice”. The victims are also transgressors and harm is inflicted on them as punishment. Plausibly, rules about corporal punishment depend on authority in a way that rules about harming the innocent do not.

Unified thalamic model generates multiple distinct oscillations with state-dependent entrainment by stimulation.

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Guoshi Li

2017-10-01

Full Text Available The thalamus plays a critical role in the genesis of thalamocortical oscillations, yet the underlying mechanisms remain elusive. To understand whether the isolated thalamus can generate multiple distinct oscillations, we developed a biophysical thalamic model to test the hypothesis that generation of and transition between distinct thalamic oscillations can be explained as a function of neuromodulation by acetylcholine (ACh and norepinephrine (NE and afferent synaptic excitation. Indeed, the model exhibited four distinct thalamic rhythms (delta, sleep spindle, alpha and gamma oscillations that span the physiological states corresponding to different arousal levels from deep sleep to focused attention. Our simulation results indicate that generation of these distinct thalamic oscillations is a result of both intrinsic oscillatory cellular properties and specific network connectivity patterns. We then systematically varied the ACh/NE and input levels to generate a complete map of the different oscillatory states and their transitions. Lastly, we applied periodic stimulation to the thalamic network and found that entrainment of thalamic oscillations is highly state-dependent. Our results support the hypothesis that ACh/NE modulation and afferent excitation define thalamic oscillatory states and their response to brain stimulation. Our model proposes a broader and more central role of the thalamus in the genesis of multiple distinct thalamo-cortical rhythms than previously assumed.

SIFT-CCH: Increasing the SIFT distinctness by color co-occurrence histograms

OpenAIRE

ANCUTI, Cosmin; BEKAERT, Philippe

2007-01-01

Describing regions in a distinctive way, in order to find correct correspondences in images of two separated views, represents a complex and essential task of computer vision. Until now, SIFT (Scale Invariant Feature Transform) has been proven to be the most reliable descriptor among the others. One of the main drawbacks of SIFT is its vulnerability to color images, being designed mainly for the gray images. To overcome this problem and also to increase the overall distinctness of the SIFT ...

Distinct types of glial cells populate the Drosophila antenna

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Jhaveri Dhanisha

2005-11-01

Full Text Available Abstract Background The development of nervous systems involves reciprocal interactions between neurons and glia. In the Drosophila olfactory system, peripheral glial cells arise from sensory lineages specified by the basic helix-loop-helix transcription factor, Atonal. These glia wrap around the developing olfactory axons early during development and pattern the three distinct fascicles as they exit the antenna. In the moth Manduca sexta, an additional set of central glia migrate to the base of the antennal nerve where axons sort to their glomerular targets. In this work, we have investigated whether similar types of cells exist in the Drosophila antenna. Results We have used different P(Gal4 lines to drive Green Fluorescent Protein (GFP in distinct populations of cells within the Drosophila antenna. Mz317::GFP, a marker for cell body and perineural glia, labels the majority of peripheral glia. An additional ~30 glial cells detected by GH146::GFP do not derive from any of the sensory lineages and appear to migrate into the antenna from the brain. Their appearance in the third antennal segment is regulated by normal function of the Epidermal Growth Factor receptor and small GTPases. We denote these distinct populations of cells as Mz317-glia and GH146-glia respectively. In the adult, processes of GH146-glial cells ensheath the olfactory receptor neurons directly, while those of the Mz317-glia form a peripheral layer. Ablation of GH146-glia does not result in any significant effects on the patterning of the olfactory receptor axons. Conclusion We have demonstrated the presence of at least two distinct populations of glial cells within the Drosophila antenna. GH146-glial cells originate in the brain and migrate to the antenna along the newly formed olfactory axons. The number of cells populating the third segment of the antenna is regulated by signaling through the Epidermal Growth Factor receptor. These glia share several features of the sorting

The rhetorician's craft, distinctions in science, and political morality

OpenAIRE

Sadler, John Z

2006-01-01

Abstract In his response to Szasz' Secular Humanism and Scientific Psychiatry, the author considers the use of rhetorical devices in Szasz' work, Szasz' avoidance of acknowledging psychiatry's scientific distinctions, and Szaszian libertarianism versus liberalism.

Streptococcus pneumoniae and Pseudomonas aeruginosa pneumonia induce distinct host responses.

Science.gov (United States)

McConnell, Kevin W; McDunn, Jonathan E; Clark, Andrew T; Dunne, W Michael; Dixon, David J; Turnbull, Isaiah R; Dipasco, Peter J; Osberghaus, William F; Sherman, Benjamin; Martin, James R; Walter, Michael J; Cobb, J Perren; Buchman, Timothy G; Hotchkiss, Richard S; Coopersmith, Craig M

2010-01-01

Pathogens that cause pneumonia may be treated in a targeted fashion by antibiotics, but if this therapy fails, then treatment involves only nonspecific supportive measures, independent of the inciting infection. The purpose of this study was to determine whether host response is similar after disparate infections with similar mortalities. Prospective, randomized controlled study. Animal laboratory in a university medical center. Pneumonia was induced in FVB/N mice by either Streptococcus pneumoniae or two different concentrations of Pseudomonas aeruginosa. Plasma and bronchoalveolar lavage fluid from septic animals was assayed by a microarray immunoassay measuring 18 inflammatory mediators at multiple time points. The host response was dependent on the causative organism as well as kinetics of mortality, but the pro-inflammatory and anti-inflammatory responses were independent of inoculum concentration or degree of bacteremia. Pneumonia caused by different concentrations of the same bacteria, Pseudomonas aeruginosa, also yielded distinct inflammatory responses; however, inflammatory mediator expression did not directly track the severity of infection. For all infections, the host response was compartmentalized, with markedly different concentrations of inflammatory mediators in the systemic circulation and the lungs. Hierarchical clustering analysis resulted in the identification of five distinct clusters of the host response to bacterial infection. Principal components analysis correlated pulmonary macrophage inflammatory peptide-2 and interleukin-10 with progression of infection, whereas elevated plasma tumor necrosis factor sr2 and macrophage chemotactic peptide-1 were indicative of fulminant disease with >90% mortality within 48 hrs. Septic mice have distinct local and systemic responses to Streptococcus pneumoniae and Pseudomonas aeruginosa pneumonia. Targeting specific host inflammatory responses induced by distinct bacterial infections could represent a

Distinct collective states due to trade-off between attractive and repulsive couplings

Science.gov (United States)

Sathiyadevi, K.; Chandrasekar, V. K.; Senthilkumar, D. V.; Lakshmanan, M.

2018-03-01

We investigate the effect of repulsive coupling together with an attractive coupling in a network of nonlocally coupled oscillators. To understand the complex interaction between these two couplings we introduce a control parameter in the repulsive coupling which plays a crucial role in inducing distinct complex collective patterns. In particular, we show the emergence of various cluster chimera death states through a dynamically distinct transition route, namely the oscillatory cluster state and coherent oscillation death state as a function of the repulsive coupling in the presence of the attractive coupling. In the oscillatory cluster state, the oscillators in the network are grouped into two distinct dynamical states of homogeneous and inhomogeneous oscillatory states. Further, the network of coupled oscillators follow the same transition route in the entire coupling range. Depending upon distinct coupling ranges, the system displays different number of clusters in the death state and oscillatory state. We also observe that the number of coherent domains in the oscillatory cluster state exponentially decreases with increase in coupling range and obeys a power-law decay. Additionally, we show analytical stability for observed solitary state, synchronized state, and incoherent oscillation death state.

Adaptation of flower and fruit colours to multiple, distinct mutualists.

Science.gov (United States)

Renoult, Julien P; Valido, Alfredo; Jordano, Pedro; Schaefer, H Martin

2014-01-01

Communication in plant-animal mutualisms frequently involves multiple perceivers. A fundamental uncertainty is whether and how species adapt to communicate with groups of mutualists having distinct sensory abilities. We quantified the colour conspicuousness of flowers and fruits originating from one European and two South American plant communities, using visual models of pollinators (bee and fly) and seed dispersers (bird, primate and marten). We show that flowers are more conspicuous than fruits to pollinators, and the reverse to seed dispersers. In addition, flowers are more conspicuous to pollinators than to seed dispersers and the reverse for fruits. Thus, despite marked differences in the visual systems of mutualists, flower and fruit colours have evolved to attract multiple, distinct mutualists but not unintended perceivers. We show that this adaptation is facilitated by a limited correlation between flower and fruit colours, and by the fact that colour signals as coded at the photoreceptor level are more similar within than between functional groups (pollinators and seed dispersers). Overall, these results provide the first quantitative demonstration that flower and fruit colours are adaptations allowing plants to communicate simultaneously with distinct groups of mutualists. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Differential autoshaping to common and distinctive elements of positive and negative discriminative stimuli.

Science.gov (United States)

Wasserman, E A; Anderson, P A

1974-11-01

The learning by hungry pigeons of a discrimination between two successively presented compound visual stimuli was investigated using a two-key autoshaping procedure. Common and distinctive stimulus elements were simultaneously presented on separate keys and either followed by food delivery, S+, or not, S-. The subjects acquired both between-trial and within-trial discriminations. On S+ trials, pigeons pecked the distinctive stimulus more than the common stimulus; before responding ceased on S- trials, they pecked the common stimulus more than the distinctive one. Mastery of the within-display discrimination during S+ trials preceded mastery of the between-trials discrimination. These findings extend the Jenkins-Sainsbury analysis of discriminations based upon a single distinguishing feature to discriminations in which common and distinctive elements are associated with both the positive and negative discriminative stimuli. The similarity of these findings to other effects found in autoshaping-approach to signals that forecast reinforcement and withdrawal from signals that forecast nonreinforcement-is also discussed.

Distinct Hippocampal Pathways Mediate Dissociable Roles of Context in Memory Retrieval.

Science.gov (United States)

Xu, Chun; Krabbe, Sabine; Gründemann, Jan; Botta, Paolo; Fadok, Jonathan P; Osakada, Fumitaka; Saur, Dieter; Grewe, Benjamin F; Schnitzer, Mark J; Callaway, Edward M; Lüthi, Andreas

2016-11-03

Memories about sensory experiences are tightly linked to the context in which they were formed. Memory contextualization is fundamental for the selection of appropriate behavioral reactions needed for survival, yet the underlying neuronal circuits are poorly understood. By combining trans-synaptic viral tracing and optogenetic manipulation, we found that the ventral hippocampus (vHC) and the amygdala, two key brain structures encoding context and emotional experiences, interact via multiple parallel pathways. A projection from the vHC to the basal amygdala mediates fear behavior elicited by a conditioned context, whereas a parallel projection from a distinct subset of vHC neurons onto midbrain-projecting neurons in the central amygdala is necessary for context-dependent retrieval of cued fear memories. Our findings demonstrate that two fundamentally distinct roles of context in fear memory retrieval are processed by distinct vHC output pathways, thereby allowing for the formation of robust contextual fear memories while preserving context-dependent behavioral flexibility. Copyright © 2016 Elsevier Inc. All rights reserved.

Crafty Entanglements: Knitting and Hard Distinctions in Aesthetics and Political Theory

Directory of Open Access Journals (Sweden)

Kate M. Daley

2013-01-01

Full Text Available Many theoretical writings on aesthetics and politics rely on hard distinctions between what is and is not art, and what is and is not political. In this article, I draw on the work of theorists, knitters, and fiber artists to argue that hand knitting provides a lens through which to unsettle some of these distinctions. I illustrate some of the ways in which aesthetic theory relies on hard distinctions between art and not-art and politics and not-politics, with particular focus on the work of Kant, Hegel, Heidegger, and Rancière. I explain how knitting is often seen as falling clearly outside the definitions of art and politics, and explore the surprising ways in which knitting shows the instability of these categories and expectations. I show that common social traditions and practices that often go unanalyzed can provide insight into the limitations and complexities of prevalent theoretical assumptions.

What History Tells Us about the Distinct Nature of Chemistry.

Science.gov (United States)

Chang, Hasok

2017-11-01

Attention to the history of chemistry can help us recognise the characteristics of chemistry that have helped to maintain it as a separate scientific discipline with a unique identity. Three such features are highlighted in this paper. First, chemistry has maintained a distinct type of theoretical thinking, independent from that of physics even in the era of quantum chemistry. Second, chemical research has always been shaped by its ineliminable practical relevance and usefulness. Third, the lived experience of chemistry, spanning the laboratory, the classroom and everyday life, is distinctive in its multidimensional sensuousness. Furthermore, I argue that the combination of these three features makes chemistry an exemplary science.

The rhetorician's craft, distinctions in science, and political morality

Science.gov (United States)

Sadler, John Z

2006-01-01

In his response to Szasz' Secular Humanism and Scientific Psychiatry, the author considers the use of rhetorical devices in Szasz' work, Szasz' avoidance of acknowledging psychiatry's scientific distinctions, and Szaszian libertarianism versus liberalism. PMID:16759356

Fetterman-House: A Process Use Distinction and a Theory.

Science.gov (United States)

Fetterman, David

2003-01-01

Discusses the concept of process use as an important distinction between the evaluation theories of E. House and D. Fetterman, thus helping to explain the discordant results of C. Christie for these two theories. (SLD)

Evaluation of the Chagas disease control program in Açucena Municipality, Rio Doce Valley, State of Minas Gerais, Brazil.

Science.gov (United States)

Santos, Adriana dos; Letro, Rejane Balmant; Lemos do Bem, Vitor Antônio; Azeredo, Bernardino Vaz de Melo; Coelho, George Luiz Lins Machado; Diotaiuti, Liléia; Machado-de-Assis, Girley Francisco; de Lana, Marta

2014-01-01

Açucena Municipality, Rio Doce Valley, State of Minas Gerais, Brazil temporarily (2001-2005) interrupted epidemiological surveillance for Chagas disease. The objective of this work was to evaluate the Chagas Disease Control Program (CDCP) in Açucena and to offer suggestions for improving local epidemiological surveillance. This study was conducted in three phases: I) a serological investigation of schoolchildren aged 5 to 15 years using an enzyme-linked immunosorbent assay (ELISA) test performed on blood collected on filter paper followed by ELISA, indirect immunofluorescence (IIF) and indirect hemaglutination (IHA) on venous blood for borderline cases and those in the gray zone of reactivity; II) vector evaluation using the data obtained by local health agents during 2006-2010; and III) examination by ELISA, IIF and IHA of serum samples from the inhabitants of houses where infected Triatoma vitticeps was found and evaluation of their knowledge about Chagas disease. Five individuals had inconclusive results in the ELISA screening but were seronegative for Chagas disease. The triatomine evaluation revealed the presence of three species: Triatoma vitticeps, Panstrongylus megistus and Panstrongylus diasi. Triatoma vitticeps was the most prevalent and widespread, with a higher (67%) index of Trypanosoma cruzi flagellates and evidence of colonization. Most of the inhabitants of the infested houses recognized triatomines and had basic knowledge about Chagas disease. Although T. vitticeps is not clearly associated with Chagas disease transmission, these results highlight the importance of maintaining CDCP in endemic areas and the need for greater emphasis on epidemiological surveillance, especially in areas with important vectorial changes or that have been modified by human intervention.

On the genus Panstrongylus Berg 1879: evolution, ecology and epidemiological significance.

Science.gov (United States)

Patterson, James S; Barbosa, Silvia E; Feliciangeli, M Dora

2009-01-01

The genus Panstrongylus is currently composed of 13 species, several of which are involved in the transmission of Trypanosoma cruzi to humans in South and Central America. Some species exhibit minor morphological differences possibly associated with adaptation to different silvatic ecotopes or domestic environments. We present a distillation of past and recent literature pertaining to the biology of this group. In particular, we summarise the current status of the genus according to systematic and recent phylogenetic studies. In light of recent evidence suggesting polyphyly/paraphyly of the genus we have investigated the possible mechanisms of morphological convergence/divergence. By assessing postembryonic ontogeny we reveal that the distinctive head shape of Panstrongylus can be derived from a Triatoma-like head late in development. A comprehensive phylogenetic study is therefore required to elucidate their relationship with Triatoma spp., and other genera of the tribe Triatomini. We also present a comparative summary of biology, ecology and epidemiological significance for each species in the genus. This reveals that knowledge of many species is fragmentary or lacking. This is mainly due to the fact that, except for few species with synanthropic traits (P. megistus and P. lignarius [formerly P. herreri]), important vectors of Chagas disease in Brazil and Peru, the majority are sylvatic species, associated with a wide variety of habitats and wild animals (many of them reservoirs of Trypanosoma cruzi). However, trends to invade human dwellings and to establish domestic colonies have been observed in several species in the genus (P. geniculatus, P. rufotuberculatus, P. lutzi, P. chinai), while others are opportunistic species (e.g. P. lignarius in the Amazon basin flying from wild ecotopes to houses on occasion without colonizing). Nevertheless, they can play some role in the transmission of sylvatic T. cruzi to humans. Research on the genus Panstrongylus requires

The rhetorician's craft, distinctions in science, and political morality

Directory of Open Access Journals (Sweden)

Sadler John Z

2006-05-01

Full Text Available Abstract In his response to Szasz' Secular Humanism and Scientific Psychiatry, the author considers the use of rhetorical devices in Szasz' work, Szasz' avoidance of acknowledging psychiatry's scientific distinctions, and Szaszian libertarianism versus liberalism.

Identification of distinct phenotypes of locally advanced pancreatic adenocarcinoma.

LENUS (Irish Health Repository)

Teo, Minyuen

2013-03-01

A significant number of pancreatic ductal adenocarcinoma present as locally advanced disease. Optimal treatment remains controversial. We sought to analyze the clinical course of locally advanced pancreatic adenocarcinoma (LAPC) in order to identify potential distinct clinical phenotypes.

Touch communicates distinct emotions.

Science.gov (United States)

Hertenstein, Matthew J; Keltner, Dacher; App, Betsy; Bulleit, Brittany A; Jaskolka, Ariane R

2006-08-01

The study of emotional signaling has focused almost exclusively on the face and voice. In 2 studies, the authors investigated whether people can identify emotions from the experience of being touched by a stranger on the arm (without seeing the touch). In the 3rd study, they investigated whether observers can identify emotions from watching someone being touched on the arm. Two kinds of evidence suggest that humans can communicate numerous emotions with touch. First, participants in the United States (Study 1) and Spain (Study 2) could decode anger, fear, disgust, love, gratitude, and sympathy via touch at much-better-than-chance levels. Second, fine-grained coding documented specific touch behaviors associated with different emotions. In Study 3, the authors provide evidence that participants can accurately decode distinct emotions by merely watching others communicate via touch. The findings are discussed in terms of their contributions to affective science and the evolution of altruism and cooperation. (c) 2006 APA, all rights reserved

The Distinction Between Curative and Assistive Technology.

Science.gov (United States)

Stramondo, Joseph A

2018-05-01

Disability activists have sometimes claimed their disability has actually increased their well-being. Some even say they would reject a cure to keep these gains. Yet, these same activists often simultaneously propose improvements to the quality and accessibility of assistive technology. However, for any argument favoring assistive over curative technology (or vice versa) to work, there must be a coherent distinction between the two. This line is already vague and will become even less clear with the emergence of novel technologies. This paper asks and tries to answer the question: what is it about the paradigmatic examples of curative and assistive technologies that make them paradigmatic and how can these defining features help us clarify the hard cases? This analysis will begin with an argument that, while the common views of this distinction adequately explain the paradigmatic cases, they fail to accurately pick out the relevant features of those technologies that make them paradigmatic and to provide adequate guidance for parsing the hard cases. Instead, it will be claimed that these categories of curative or assistive technologies are defined by the role the technologies play in establishing a person's relational narrative identity as a member of one of two social groups: disabled people or non-disabled people.

Corticosteroid receptors adopt distinct cyclical transcriptional signatures.

Science.gov (United States)

Le Billan, Florian; Amazit, Larbi; Bleakley, Kevin; Xue, Qiong-Yao; Pussard, Eric; Lhadj, Christophe; Kolkhof, Peter; Viengchareun, Say; Fagart, Jérôme; Lombès, Marc

2018-05-07

Mineralocorticoid receptors (MRs) and glucocorticoid receptors (GRs) are two closely related hormone-activated transcription factors that regulate major pathophysiologic functions. High homology between these receptors accounts for the crossbinding of their corresponding ligands, MR being activated by both aldosterone and cortisol and GR essentially activated by cortisol. Their coexpression and ability to bind similar DNA motifs highlight the need to investigate their respective contributions to overall corticosteroid signaling. Here, we decipher the transcriptional regulatory mechanisms that underlie selective effects of MRs and GRs on shared genomic targets in a human renal cellular model. Kinetic, serial, and sequential chromatin immunoprecipitation approaches were performed on the period circadian protein 1 ( PER1) target gene, providing evidence that both receptors dynamically and cyclically interact at the same target promoter in a specific and distinct transcriptional signature. During this process, both receptors regulate PER1 gene by binding as homo- or heterodimers to the same promoter region. Our results suggest a novel level of MR-GR target gene regulation, which should be considered for a better and integrated understanding of corticosteroid-related pathophysiology.-Le Billan, F., Amazit, L., Bleakley, K., Xue, Q.-Y., Pussard, E., Lhadj, C., Kolkhof, P., Viengchareun, S., Fagart, J., Lombès, M. Corticosteroid receptors adopt distinct cyclical transcriptional signatures.

STRUCTURAL IDENTIFICATION OF DISTINCT INVERSIONS OF PLANAR KINEMATIC CHAINS

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Dr. Shubhashis Sanyal

2011-12-01

Full Text Available 0 0 1 171 979 International Islamic University 8 2 1148 14.0 Normal 0 false false false EN-US JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Times New Roman";} Inversions are various structural possibilities of a kinematic chain. The number of inversions depends on the number of links of a kinematic chain. At the stage of structural synthesis, identification of distinct structural inversions of a particular type of kinematic chain is necessary. Various researchers have proposed methods for identification of distinct inversions. Present method based on Link joint connectivity is proposed to identify the distinct inversions of a planar kinematic chain. Method is tested successfully on single degree and multiple degree of freedom planar kinematic chains. ABSTRAK: Penyonsangan merupakan kebarangkalian pelbagai struktur suatu rangkaian kinematik. Jumlah songsangan bergantung kepada jumlah hubungan suatu rangkaian kinematik. Pada peringkat sintesis struktur, pengenalan songsangan struktur yang berbeza untuk suatu jenis rangkaian kinematik adalah perlu. Ramai penyelidik telah mencadangkan pelbagai kaedah pengenalan songsangan yang berbeza. Kaedah terkini berdasarkan hubungan kesambungan bersama telah dicadangkan untuk mengenalpasti songsangan yang berbeza dalam suatu satah rangkaian kinematik.

Distinctive safety aspects of the CANDU-PHW reactor design

International Nuclear Information System (INIS)

Kugler, G.

1980-01-01

Two lectures are presented in this report. They were prepared in response to a request from IAEA to provide information on the 'Special characteristics of the safety analysis of heavy water reactors' to delegates from member states attending the Interregional Training Course on Safety Analysis Review, held at Karlsruhe, November 19 to December 20, 1979. The CANDU-PHW reactor is used as a model for discussion. The first lecture describes the distinctive features of the CANDU reactor and how they impact on reactor safety. In the second lecture the Canadian safety philosophy, the safety design objective, and other selected topics on reactor safety analysis are discussed. The material in this report was selected with a view to assisting those not familiar with the CANDU heavy water reactor design in evaluating the distinctive safety aspects of these reactors. (auth)

Both differences in encoding processes and monitoring at retrieval reduce false alarms when distinctive information is studied.

Science.gov (United States)

Hanczakowski, Maciej; Mazzoni, Giuliana

2011-04-01

A reduction in false alarms to critical lures is observed in the DRM paradigm (Roediger & McDermott, 1995) when distinctive information is presented at encoding. Two mechanisms have been proposed to account for this reduction. According to the monitoring theory (e.g., the distinctiveness heuristic), lack of diagnostic recollection serves as a basis for discarding non-presented lures. According to the encoding theory, presenting distinctive information at study leads to impoverished relational processing, which results in a reduction in memorial information elicited by critical lures. In the present study a condition was created in which the use of the distinctiveness heuristic was precluded by associating, within the same study, lures with distinctive information in a context different from the study session. Under that condition reduction in false alarms to distinctive critical lures was still observed. This result supports the predictions of the encoding theory. However, when in the same study the use of the distinctiveness heuristic was not precluded, reductions in false alarms to unrelated lures were also observed when distinctive information was presented at study, indicating that both mechanisms are likely to contribute to the rejection of false memories.

Army nurses in wartime: distinction and pride.

Science.gov (United States)

Higgins, L P

1996-08-01

Nurses have served with distinction in wartime since Florence Nightingale went to the Crimea. Women often accompanied their husbands to battle during the Revolutionary and Civil Wars, caring for the sick and wounded. Although not officially given officer status until 1920, Army nurses served in the Spanish-American War and World War I. As officers, thousands of nurses served in subsequent wars, distinguishing themselves by their heroism, devotion to duty, and sheer tenacity of spirit.

Neonatal lethal dwarfism with distinct skeletal malformations - a separate entity?

Energy Technology Data Exchange (ETDEWEB)

Rosendahl, K.; Maurseth, K.; Olsen, Oe.E. [Dept. of Paediatric Radiology, Haukeland University Hospital, Bergen (Norway); Halvorsen, O.J. [Dept. of Pathology, Haukeland University Hospital, Bergen (Norway); Gjelland, K. [Dept. of Gynaecology, Haukeland University Hospital, Bergen (Norway); Engebretsen, L. [Dept. of Genetics, Haukeland University Hospital, Bergen (Norway)

2001-09-01

We describe a case of neonatal lethal dwarfism characterised by short trunk, short, stick-like tubular bones, deficient ossification of the axial skeleton and broad, sclerotic horizontal ribs. Two similar cases have previously been reported as examples of the Neu-Laxova syndrome. However, the radiological findings of the Neu-Laxova syndrome, as reported in 16 out of 40 documented cases, show a heterogeneous pattern of minor features, which differ distinctively from those found in the previous two cases and by us. A literature research did not reveal similar cases, and we therefore suggest that our case, together with the two previous cases, may represent a new distinctive form of neonatal lethal dwarfism. (orig.)

Neonatal lethal dwarfism with distinct skeletal malformations - a separate entity?

International Nuclear Information System (INIS)

Rosendahl, K.; Maurseth, K.; Olsen, Oe.E.; Halvorsen, O.J.; Gjelland, K.; Engebretsen, L.

2001-01-01

We describe a case of neonatal lethal dwarfism characterised by short trunk, short, stick-like tubular bones, deficient ossification of the axial skeleton and broad, sclerotic horizontal ribs. Two similar cases have previously been reported as examples of the Neu-Laxova syndrome. However, the radiological findings of the Neu-Laxova syndrome, as reported in 16 out of 40 documented cases, show a heterogeneous pattern of minor features, which differ distinctively from those found in the previous two cases and by us. A literature research did not reveal similar cases, and we therefore suggest that our case, together with the two previous cases, may represent a new distinctive form of neonatal lethal dwarfism. (orig.)

Blurring Boundaries : Carnap, Quine, and the Internal-External Distinction

NARCIS (Netherlands)

Verhaegh, Sander

Quine is routinely perceived as saving metaphysics from Carnapian positivism. Where Carnap rejects metaphysical existence claims as meaningless, Quine is taken to restore their intelligibility by dismantling the former's internal-external distinction. The problem with this picture, however, is that

BMP signalling differentially regulates distinct haematopoietic stem cell types

NARCIS (Netherlands)

M. Crisan (Mihaela); P. Solaimani Kartalaei (Parham); C.S. Vink (Chris); T. Yamada-Inagawa (Tomoko); K. Bollerot (Karine); W.F.J. van IJcken (Wilfred); R. Van Der Linden (Reinier); S.C. de Sousa Lopes (Susana Chuva); R. Monteiro (Rui); C.L. Mummery (Christine); E.A. Dzierzak (Elaine)

2015-01-01

textabstractAdult haematopoiesis is the outcome of distinct haematopoietic stem cell (HSC) subtypes with self-renewable repopulating ability, but with different haematopoietic cell lineage outputs. The molecular basis for this heterogeneity is largely unknown. BMP signalling regulates HSCs as they

Everyday distinction and omnivorous orientation: An analysis of food choice, attitudinal dispositions and social background.

Science.gov (United States)

Kahma, Nina; Niva, Mari; Helakorpi, Satu; Jallinoja, Piia

2016-01-01

In recent years studies on cultural consumption have experienced a Bourdieusian renaissance. This is indicated by a growing body of research analysing distinctions in different areas of culture, and numerous studies on the homology thesis applying the concepts of distinction, field and capital. Concurrently, however, it has been argued that instead of distinctive tastes, distinction and class status are increasingly manifested by cultural omnivorousness. For a good part studies focussing on distinction in food have analysed eating out and stylization through restaurant preferences, rather than everyday food choices. In this article we investigate everyday food choices from the perspective of distinction and omnivorousness. Our analysis draws on cross-sectional quantitative data collected in 2012 among 15-64-year-old Finns (N = 2601). The article maps out the relationship between food choice frequencies, dispositions and social background with Multiple Correspondence Analysis (MCA). The results show that the consumption of fruit and vegetables, ready-meals and convenience foods were among the most divisive food choices. The first structuring dimension juxtaposed processed, fatty and sugared foods with unprocessed foods and fresh ingredients. This dimension was associated with healthiness and weight control as dispositions. On the second structuring dimension there were differences in the valuation of taste, pleasure and sociability, and a contrast between moderate and restrictive choices. Particularly the first dimension was associated with educational, occupational, and gender differences. Distinction within everyday food choices was manifested in the use of healthy and unprocessed foods and 'moderate hedonism' in contrast to more restrictive tastes. Copyright © 2015 Elsevier Ltd. All rights reserved.

The emotional memory effect: differential processing or item distinctiveness?

Science.gov (United States)

Schmidt, Stephen R; Saari, Bonnie

2007-12-01

A color-naming task was followed by incidental free recall to investigate how emotional words affect attention and memory. We compared taboo, nonthreatening negative-affect, and neutral words across three experiments. As compared with neutral words, taboo words led to longer color-naming times and better memory in both within- and between-subjects designs. Color naming of negative-emotion nontaboo words was slower than color naming of neutral words only during block presentation and at relatively short interstimulus intervals (ISIs). The nontaboo emotion words were remembered better than neutral words following blocked and random presentation and at both long and short ISIs, but only in mixed-list designs. Our results support multifactor theories of the effects of emotion on attention and memory. As compared with neutral words, threatening stimuli received increased attention, poststimulus elaboration, and benefit from item distinctiveness, whereas nonthreatening emotional stimuli benefited only from increased item distinctiveness.

Puerto Rico and Florida manatees represent genetically distinct groups

Science.gov (United States)

Hunter, Margaret E.; Mignucci-Giannoni, Antonio A.; Tucker, Kimberly Pause; King, Timothy L.; Bonde, Robert K.; Gray, Brian A.; McGuire, Peter M.

2012-01-01

The West Indian manatee (Trichechus manatus) populations in Florida (T. m. latirostris) and Puerto Rico (T. m. manatus) are considered distinct subspecies and are listed together as endangered under the United States Endangered Species Act. Sustained management and conservation efforts for the Florida subspecies have led to the suggested reclassification of the species to a threatened or delisted status. However, the two populations are geographically distant, morphologically distinct, and habitat degradation and boat strikes continue to threaten the Puerto Rico population. Here, 15 microsatellite markers and mitochondrial control region sequences were used to determine the relatedness of the two populations and investigate the genetic diversity and phylogeographic organization of the Puerto Rico population. Highly divergent allele frequencies were identified between Florida and Puerto Rico using microsatellite (F ST = 0.16; R ST = 0.12 (P ST = 0.66; Φ ST = 0.50 (P E = 0.45; NA = 3.9), were similar, but lower than those previously identified in Florida (HE = 0.48, NA = 4.8). Within Puerto Rico, the mitochondrial genetic diversity values (π = 0.001; h = 0.49) were slightly lower than those previously reported (π = 0.002; h = 0.54) and strong phylogeographic structure was identified (F ST global = 0.82; Φ ST global = 0.78 (P population size (N = 250), and distinct threats and habitat emphasize the need for separate protections in Puerto Rico. Conservation efforts including threat mitigation, migration corridors, and protection of subpopulations could lead to improved genetic variation in the endangered Puerto Rico manatee population.

Acute Chagas' cardiopathy in a polar bear (Ursus maritimus in Guadalajara, Mexico

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J. Jaime-Andrade G.

1997-08-01

Full Text Available We report a 24 year old female polar bear (Ursus maritimus who contracted Chagas' infection at the Guadalajara Zoo, in Jalisco, México, and died of acute Chagas' carditis 15 days later. The histopathological findings are described, as well as the presence of triatomines (Triatoma longipennis Usinger infected with Trypanosoma cruzi collected within 5 meters from the place where the animal lived in the city of Guadalajara.Relatamos o caso de uma ursa polar (Ursus maritimus de 24 anos de idade, que contraiu a infecção chagásica no Zoológico de Guadalajara, em Jalisco, no México, e morreu de cardite chagásica aguda 15 dias após o início da sintomatologia. Os achados histopatológicos são descritos, bem como a presença de triatomíneos (Triatoma longipennis Usinger infectados por Trypanosoma cruzi coletados a 5 metros do local onde o animal vivia, na cidade de Guadalajara.

Molecular polymorphism of a cell surface proteoglycan: distinct structures on simple and stratified epithelia.

Science.gov (United States)

Sanderson, R D; Bernfield, M

1988-12-01

Epithelial cells are organized into either a single layer (simple epithelia) or multiple layers (stratified epithelia). Maintenance of these cellular organizations requires distinct adhesive mechanisms involving many cell surface molecules. One such molecule is a cell surface proteoglycan, named syndecan, that contains both heparan sulfate and chondroitin sulfate chains. This proteoglycan binds cells to fibrillar collagens and fibronectin and thus acts as a receptor for interstitial matrix. The proteoglycan is restricted to the basolateral surface of simple epithelial cells, but is located over the entire surface of stratified epithelial cells, even those surfaces not contacting matrix. We now show that the distinct localization in simple and stratified epithelia correlates with a distinct proteoglycan structure. The proteoglycan from simple epithelia (modal molecular size, 160 kDa) is larger than that from stratified epithelia (modal molecular size, 92 kDa), but their core proteins are identical in size and immunoreactivity. The proteoglycan from simple epithelia has more and larger heparan sulfate and chondroitin sulfate chains than the proteoglycan from stratified epithelia. Thus, the cell surface proteoglycan shows a tissue-specific structural polymorphism due to distinct posttranslational modifications. This polymorphism likely reflects distinct proteoglycan functions in simple and stratified epithelia, potentially meeting the different adhesive requirements of the cells in these different organizations.

New approach to equipment quality evaluation method with distinct functions

Directory of Open Access Journals (Sweden)

Milisavljević Vladimir M.

2016-01-01

Full Text Available The paper presents new approach for improving method for quality evaluation and selection of equipment (devices and machinery by applying distinct functions. Quality evaluation and selection of devices and machinery is a multi-criteria problem which involves the consideration of numerous parameters of various origins. Original selection method with distinct functions is based on technical parameters with arbitrary evaluation of each parameter importance (weighting. Improvement of this method, presented in this paper, addresses the issue of weighting of parameters by using Delphi Method. Finally, two case studies are provided, which included quality evaluation of standard boilers for heating and evaluation of load-haul-dump (LHD machines, to demonstrate applicability of this approach. Analytical Hierarchical Process (AHP is used as a control method.

Francis Bacon and the Art-Nature Distinction.

Science.gov (United States)

Weeks, Sophie

2007-07-01

Commentators generally expound Bacon's position on the art-nature relationship in terms of how much it retained or departed from traditional conceptions. This paper argues that an appreciation of the Baconian meaning of the terms "art" and "nature" requires a close examination of his wider cosmogonical speculations. Bacon's cosmogonical account moves from a state of unbridled chaos to the relatively stable system for which the term "nature" is normally used. The fundamental principle lying at the heart of Baconian cosmogony is an enriched and appetitive matter: eternal, unchanging, and the plenipotentiary source of all things. Successive limitations of matter's absolute power produced a lazy and habitual nature, which Bacon labelled "nature free." To shift nature from this otiose condition, the Baconian operator recapitulates the original binding of matter. Bacon designated the systematic procedures of binding nature the science of magic. Magic is Bacon's human counterpart to the original cosmogonical process that gave rise to the current system of nature. In Bacon's cosmogony, all possible worlds unfold out of matter: the function of art is to shake out nature's hidden folds. Hence, the distinction between naturalia and artificialia maps on to the distinction between actual and potential. Nature free is without purpose, but art - nature bound - knowingly brings into being an alternative nature designed for human utility.

The neural signatures of distinct psychopathic traits.

Science.gov (United States)

Carré, Justin M; Hyde, Luke W; Neumann, Craig S; Viding, Essi; Hariri, Ahmad R

2013-01-01

Recent studies suggest that psychopathy may be associated with dysfunction in the neural circuitry supporting both threat- and reward-related processes. However, these studies have involved small samples and often focused on extreme groups. Thus, it is unclear to what extent current findings may generalize to psychopathic traits in the general population. Furthermore, no studies have systematically and simultaneously assessed associations between distinct psychopathy facets and both threat- and reward-related brain function in the same sample of participants. Here, we examined the relationship between threat-related amygdala reactivity and reward-related ventral striatum (VS) reactivity and variation in four facets of self-reported psychopathy in a sample of 200 young adults. Path models indicated that amygdala reactivity to fearful facial expressions is negatively associated with the interpersonal facet of psychopathy, whereas amygdala reactivity to angry facial expressions is positively associated with the lifestyle facet. Furthermore, these models revealed that differential VS reactivity to positive versus negative feedback is negatively associated with the lifestyle facet. There was suggestive evidence for gender-specific patterns of association between brain function and psychopathy facets. Our findings are the first to document differential associations between both threat- and reward-related neural processes and distinct facets of psychopathy and thus provide a more comprehensive picture of the pattern of neural vulnerabilities that may predispose to maladaptive outcomes associated with psychopathy.

Differential autoshaping to common and distinctive elements of positive and negative discriminative stimuli1

Science.gov (United States)

Wasserman, Edward A.; Anderson, Patricia A.

1974-01-01

The learning by hungry pigeons of a discrimination between two successively presented compound visual stimuli was investigated using a two-key autoshaping procedure. Common and distinctive stimulus elements were simultaneously presented on separate keys and either followed by food delivery, S+, or not, S−. The subjects acquired both between-trial and within-trial discriminations. On S+ trials, pigeons pecked the distinctive stimulus more than the common stimulus; before responding ceased on S− trials, they pecked the common stimulus more than the distinctive one. Mastery of the within-display discrimination during S+ trials preceded mastery of the between-trials discrimination. These findings extend the Jenkins-Sainsbury analysis of discriminations based upon a single distinguishing feature to discriminations in which common and distinctive elements are associated with both the positive and negative discriminative stimuli. The similarity of these findings to other effects found in autoshaping—approach to signals that forecast reinforcement and withdrawal from signals that forecast nonreinforcement—is also discussed. PMID:16811812

Ataques de nervios: culturally bound and distinct from panic attacks?

Science.gov (United States)

Keough, Meghan E; Timpano, Kiara R; Schmidt, Norman B

2009-01-01

The Diagnostic and Statistical Manual of Mental Disorders [DSM-IV-TR; American Psychiatric Association [APA], 2000) has emphasized the importance of understanding psychopathology within a cultural framework by including culture-bound syndromes within its appendices. These syndromes are proposed to be bound to certain cultures and distinct from other psychological disorders. Included among the syndromes are ataques de nervios (ADN), which are reported to be bound to the Hispanic culture and closely resemble panic attacks. However, the cultural distinctiveness and phenomenology of ADN has not been adequately investigated. The current study employed an ethnically diverse study sample (N=342) of undergraduates. Participants completed a number of measures that assessed acculturation, syndrome and anxiety risk factors. In contrast to the DSM-IV's conceptualization of ADN, the rate of ADN did not significantly vary across the three main groups (African American, Caucasian, and Hispanic participants) nor did it vary based on acculturation. More consistent with the DSM-IV, the symptom comparisons indicated some differentiation between ADN and panic attacks. The present report provides data indicating that ADNs, as described by the DSM-IV, are not unique to the Hispanic culture and are experienced by non-Hispanic individuals at similar rates to Hispanic-endorsement. The findings are consistent with the DSM-IV assertion that ADNs and PAs are distinct syndromes. (c) 2008 Wiley-Liss, Inc.

Effectiveness, Improvement and Educational Change: A Distinctively Canadian Approach?

Science.gov (United States)

Hargreaves, Andy; Fink, Dean

1998-01-01

A distinctive Canadian school of thought on educational change is inclined to synthesize diverse bodies of work and integrate nonrational and emotional dimensions with rational and technically effective ones in a socially critical way. Highlights the Canadian perspective through discussions about complex systems, contexts of change, critical…

48 CFR 307.7001 - Distinction between acquisition and assistance.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Distinction between acquisition and assistance. 307.7001 Section 307.7001 Federal Acquisition Regulations System HEALTH AND HUMAN... barter, of property or services for the direct benefit or use of the Government; or (2) Government...

What Makes Counsellors Working in Primary Care Distinct from Counsellors Working in Other Settings?

Science.gov (United States)

Hudson-Allez, Glyn

2000-01-01

Counseling in primary care can be considered a fast-evolving profession that is distinct from counseling in the private sector. Differences in counselor roles, specifically confidentiality ethics and working hours, are discussed. Referrals and attrition are also discussed. The distinctiveness of primary care counseling versus working in more…

Reduced effects of pictorial distinctiveness on false memory following dynamic visual noise.

Science.gov (United States)

Parker, Andrew; Kember, Timothy; Dagnall, Neil

2017-07-01

High levels of false recognition for non-presented items typically occur following exposure to lists of associated words. These false recognition effects can be reduced by making the studied items more distinctive by the presentation of pictures during encoding. One explanation of this is that during recognition, participants expect or attempt to retrieve distinctive pictorial information in order to evaluate the study status of the test item. If this involves the retrieval and use of visual imagery, then interfering with imagery processing should reduce the effectiveness of pictorial information in false memory reduction. In the current experiment, visual-imagery processing was disrupted at retrieval by the use of dynamic visual noise (DVN). It was found that effects of DVN dissociated true from false memory. Memory for studied words was not influenced by the presence of an interfering noise field. However, false memory was increased and the effects of picture-induced distinctiveness was eliminated. DVN also increased false recollection and remember responses to unstudied items.

Historical note on Loa loa: a reinterpretation.

Science.gov (United States)

Grützig, J; Jennes, B

1977-07-01

Loa loa, also known as the African eye worm, is a common parasite in the central part of West Africa. As Chrysops silacea and C. dimidiata, the only important vectors of loaiasis, are found exclusively in the tropical rain forests of West Africa, the parasite's transmission is confined to this region. References by early writers to the extraction of Loa loa from the eye of a man on the Island of Ormus (today known as Hormuz or Hormus) in the Persian Gulf apparently were based on a misinterpretation of an illustration by de Bry (1595) of the blinding of a royal relative.

Distinction of Fly Artifacts from Human Blood using Immunodetection.

Science.gov (United States)

Rivers, David B; Acca, Gillian; Fink, Marc; Brogan, Rebecca; Chen, Dorothy; Schoeffield, Andrew

2018-02-21

Insect stains produced by necrophagous flies are indistinguishable morphologically from human bloodstains. At present, no diagnostic tests exist to overcome this deficiency. As the first step toward developing a chemical test to recognize fly artifacts, polyclonal antisera were generated in rats against three distinct antigenic sequences of fly cathepsin D-like proteinase, an enzyme that is structurally distinct in cyclorrhaphous Diptera from other animals. The resulting rat antisera bound to artifacts produced by Protophormia terraenovae and synthetic peptides used to generate the polyclonal antisera, but not with any type of mammalian blood tested in immunoassays. Among the three antisera, anti-md3 serum displayed the highest reactivity for fly stains, demonstrated cross-reactivity for all synthetic peptides representing antigenic sequences of the mature fly enzyme, and bound artifacts originating from the fly digestive tract. Further work is needed to determine whether the antisera are suitable for non-laboratory conditions. © 2018 American Academy of Forensic Sciences.

Common and distinct brain networks underlying panic and social anxiety disorders.

Science.gov (United States)

Kim, Yong-Ku; Yoon, Ho-Kyoung

2018-01-03

Although panic disorder (PD) and phobic disorders are independent anxiety disorders with distinct sets of diagnostic criteria, there is a high level of overlap between them in terms of pathogenesis and neural underpinnings. Functional connectivity research using resting-state functional magnetic resonance imaging (rsfMRI) shows great potential in identifying the similarities and differences between PD and phobias. Understanding common and distinct networks between PD and phobic disorders is critical for identifying both specific and general neural characteristics of these disorders. We review recent rsfMRI studies and explore the clinical relevance of resting-state functional connectivity (rsFC) in PD and phobias. Although findings differ between studies, there are some meaningful, consistent findings. Social anxiety disorder (SAD) and PD share common default mode network alterations. Alterations within the sensorimotor network are observed primarily in PD. Increased connectivity in the salience network is consistently reported in SAD. This review supports hypotheses that PD and phobic disorders share common rsFC abnormalities and that the different clinical phenotypes between the disorders come from distinct brain functional network alterations. Copyright © 2017 Elsevier Inc. All rights reserved.

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

30 CFR 75.1720-1 - Distinctively colored hard hats, or hard caps; identification for newly employed, inexperienced...

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Distinctively colored hard hats, or hard caps... STANDARDS-UNDERGROUND COAL MINES Miscellaneous § 75.1720-1 Distinctively colored hard hats, or hard caps; identification for newly employed, inexperienced miners. Hard hats or hard caps distinctively different in color...

14- to 16-Month-Olds Attend to Distinct Labels in an Inductive Reasoning Task.

Science.gov (United States)

Switzer, Jessica L; Graham, Susan A

2017-01-01

We examined how naming objects with unique labels influenced infants' reasoning about the non-obvious properties of novel objects. Seventy 14- to 16-month-olds participated in an imitation-based inductive inference task during which they were presented with target objects possessing a non-obvious sound property, followed by test objects that varied in shape similarity in comparison to the target. Infants were assigned to one of two groups: a No Label group in which objects were introduced with a general attentional phrase (i.e., "Look at this one") and a Distinct Label group in which target and test objects were labeled with two distinct count nouns (i.e., fep vs. wug ). Infants in the Distinct Label group performed significantly fewer target actions on the high-similarity objects than infants in the No Label group but did not differ in performance of actions on the low-similarity object. Within the Distinct Label group, performance on the inductive inference task was related to age, but not to working memory, inhibitory control, or vocabulary. Within the No Label condition, performance on the inductive inference task was related to a measure of inhibitory control. Our findings suggest that between 14- and 16-months, infants begin to use labels to carve out distinct categories, even when objects are highly perceptually similar.

14- to 16-Month-Olds Attend to Distinct Labels in an Inductive Reasoning Task

Directory of Open Access Journals (Sweden)

Susan A. Graham

2017-04-01

Full Text Available We examined how naming objects with unique labels influenced infants’ reasoning about the non-obvious properties of novel objects. Seventy 14- to 16-month-olds participated in an imitation-based inductive inference task during which they were presented with target objects possessing a non-obvious sound property, followed by test objects that varied in shape similarity in comparison to the target. Infants were assigned to one of two groups: a No Label group in which objects were introduced with a general attentional phrase (i.e., “Look at this one” and a Distinct Label group in which target and test objects were labeled with two distinct count nouns (i.e., fep vs. wug. Infants in the Distinct Label group performed significantly fewer target actions on the high-similarity objects than infants in the No Label group but did not differ in performance of actions on the low-similarity object. Within the Distinct Label group, performance on the inductive inference task was related to age, but not to working memory, inhibitory control, or vocabulary. Within the No Label condition, performance on the inductive inference task was related to a measure of inhibitory control. Our findings suggest that between 14- and 16-months, infants begin to use labels to carve out distinct categories, even when objects are highly perceptually similar.

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

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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.

Evaluation of the Chagas Disease Control Program in Açucena Municipality, Rio Doce Valley, State of Minas Gerais, Brazil

Directory of Open Access Journals (Sweden)

Adriana dos Santos

2014-04-01

Full Text Available Introduction Açucena Municipality, Rio Doce Valley, State of Minas Gerais, Brazil temporarily (2001-2005 interrupted epidemiological surveillance for Chagas disease. The objective of this work was to evaluate the Chagas Disease Control Program (CDCP in Açucena and to offer suggestions for improving local epidemiological surveillance. Methods This study was conducted in three phases: I a serological investigation of schoolchildren aged 5 to 15 years using an enzyme-linked immunosorbent assay (ELISA test performed on blood collected on filter paper followed by ELISA, indirect immunofluorescence (IIF and indirect hemaglutination (IHA on venous blood for borderline cases and those in the gray zone of reactivity; II vector evaluation using the data obtained by local health agents during 2006-2010; and III examination by ELISA, IIF and IHA of serum samples from the inhabitants of houses where infected Triatoma vitticeps was found and evaluation of their knowledge about Chagas disease. Results Five individuals had inconclusive results in the ELISA screening but were seronegative for Chagas disease. The triatomine evaluation revealed the presence of three species: Triatoma vitticeps, Panstrongylus megistus and Panstrongylus diasi. Triatoma vitticeps was the most prevalent and widespread, with a higher (67% index of Trypanosoma cruzi flagellates and evidence of colonization. Most of the inhabitants of the infested houses recognized triatomines and had basic knowledge about Chagas disease. Conclusions Although T. vitticeps is not clearly associated with Chagas disease transmission, these results highlight the importance of maintaining CDCP in endemic areas and the need for greater emphasis on epidemiological surveillance, especially in areas with important vectorial changes or that have been modified by human intervention.

30 CFR 77.1710-1 - Distinctively colored hard hats or hard caps; identification for newly employed, inexperienced...

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Distinctively colored hard hats or hard caps... Distinctively colored hard hats or hard caps; identification for newly employed, inexperienced miners. Hard hats or hard caps distinctively different in color from those worn by experienced miners shall be worn at...

Distinct patterns of epigenetic marks and transcription factor binding ...

Indian Academy of Sciences (India)

Distinct patterns of epigenetic marks and transcription factor binding sites across promoters of sense-intronic long noncoding RNAs. Sourav Ghosh, Satish Sati, Shantanu Sengupta and Vinod Scaria. J. Genet. 94, 17–25. Gencode V9 lncRNA gene : 11004. Known lncRNA : 1175. Novel lncRNA : 5898. Putative lncRNA :.

Ethical distinctions between different kinds of plant breeding

DEFF Research Database (Denmark)

Myskja, B.K.; Schouten, H.J.; Gjerris, Mickey

2015-01-01

The article discusses whether there are ethically significant distinctions between different forms of plant breeding. We distinguish different forms of plant breeding according to the kind of technology and degree of human intervention compared to plant reproduction occurring in nature. According...... differences between plant breeding methods. The framework can contribute to an improved dialogue between the scientific community and the wider public by making the scepticism towards GM-technology more intelligible....

PCR reveals significantly higher rates of Trypanosoma cruzi infection than microscopy in the Chagas vector, Triatoma infestans: High rates found in Chuquisaca, Bolivia

Directory of Open Access Journals (Sweden)

Lucero David E

2007-06-01

Full Text Available Abstract Background The Andean valleys of Bolivia are the only reported location of sylvatic Triatoma infestans, the main vector of Chagas disease in this country, and the high human prevalence of Trypanosoma cruzi infection in this region is hypothesized to result from the ability of vectors to persist in domestic, peri-domestic, and sylvatic environments. Determination of the rate of Trypanosoma infection in its triatomine vectors is an important element in programs directed at reducing human infections. Traditionally, T. cruzi has been detected in insect vectors by direct microscopic examination of extruded feces, or dissection and analysis of the entire bug. Although this technique has proven to be useful, several drawbacks related to its sensitivity especially in the case of small instars and applicability to large numbers of insects and dead specimens have motivated researchers to look for a molecular assay based on the polymerase chain reaction (PCR as an alternative for parasitic detection of T. cruzi infection in vectors. In the work presented here, we have compared a PCR assay and direct microscopic observation for diagnosis of T. cruzi infection in T. infestans collected in the field from five localities and four habitats in Chuquisaca, Bolivia. The efficacy of the methods was compared across nymphal stages, localities and habitats. Methods We examined 152 nymph and adult T. infestans collected from rural areas in the department of Chuquisaca, Bolivia. For microscopic observation, a few drops of rectal content obtained by abdominal extrusion were diluted with saline solution and compressed between a slide and a cover slip. The presence of motile parasites in 50 microscopic fields was registered using 400× magnification. For the molecular analysis, dissection of the posterior part of the abdomen of each insect followed by DNA extraction and PCR amplification was performed using the TCZ1 (5' – CGA GCT CTT GCC CAC ACG GGT GCT – 3

Visual Distinctiveness and the Development of Children's False Memories

Science.gov (United States)

Howe, Mark L.

2008-01-01

Distinctiveness effects in children's (5-, 7-, and 11-year-olds) false memory illusions were examined using visual materials. In Experiment 1, developmental trends (increasing false memories with age) were obtained using Deese-Roediger-McDermott lists presented as words and color photographs but not line drawings. In Experiment 2, when items were…

Two distinct forms of functional lateralization in the human brain

Science.gov (United States)

Gotts, Stephen J.; Jo, Hang Joon; Wallace, Gregory L.; Saad, Ziad S.; Cox, Robert W.; Martin, Alex

2013-01-01

The hemispheric lateralization of certain faculties in the human brain has long been held to be beneficial for functioning. However, quantitative relationships between the degree of lateralization in particular brain regions and the level of functioning have yet to be established. Here we demonstrate that two distinct forms of functional lateralization are present in the left vs. the right cerebral hemisphere, with the left hemisphere showing a preference to interact more exclusively with itself, particularly for cortical regions involved in language and fine motor coordination. In contrast, right-hemisphere cortical regions involved in visuospatial and attentional processing interact in a more integrative fashion with both hemispheres. The degree of lateralization present in these distinct systems selectively predicted behavioral measures of verbal and visuospatial ability, providing direct evidence that lateralization is associated with enhanced cognitive ability. PMID:23959883

SPATIALLY RESOLVED SPECTROSCOPY OF EUROPA: THE DISTINCT SPECTRUM OF LARGE-SCALE CHAOS

International Nuclear Information System (INIS)

Fischer, P. D.; Brown, M. E.; Hand, K. P.

2015-01-01

We present a comprehensive analysis of spatially resolved moderate spectral resolution near-infrared spectra obtained with the adaptive optics system at the Keck Observatory. We identify three compositionally distinct end member regions: the trailing hemisphere bullseye, the leading hemisphere upper latitudes, and a third component associated with leading hemisphere chaos units. We interpret the composition of the three end member regions to be dominated by irradiation products, water ice, and evaporite deposits or salt brines, respectively. The third component is associated with geological features and distinct from the geography of irradiation, suggesting an endogenous identity. Identifying the endogenous composition is of particular interest for revealing the subsurface composition. However, its spectrum is not consistent with linear mixtures of the salt minerals previously considered relevant to Europa. The spectrum of this component is distinguished by distorted hydration features rather than distinct spectral features, indicating hydrated minerals but making unique identification difficult. In particular, it lacks features common to hydrated sulfate minerals, challenging the traditional view of an endogenous salty component dominated by Mg-sulfates. Chloride evaporite deposits are one possible alternative

SPATIALLY RESOLVED SPECTROSCOPY OF EUROPA: THE DISTINCT SPECTRUM OF LARGE-SCALE CHAOS

Energy Technology Data Exchange (ETDEWEB)

Fischer, P. D.; Brown, M. E. [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States); Hand, K. P., E-mail: pfischer@caltech.edu [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

2015-11-15

We present a comprehensive analysis of spatially resolved moderate spectral resolution near-infrared spectra obtained with the adaptive optics system at the Keck Observatory. We identify three compositionally distinct end member regions: the trailing hemisphere bullseye, the leading hemisphere upper latitudes, and a third component associated with leading hemisphere chaos units. We interpret the composition of the three end member regions to be dominated by irradiation products, water ice, and evaporite deposits or salt brines, respectively. The third component is associated with geological features and distinct from the geography of irradiation, suggesting an endogenous identity. Identifying the endogenous composition is of particular interest for revealing the subsurface composition. However, its spectrum is not consistent with linear mixtures of the salt minerals previously considered relevant to Europa. The spectrum of this component is distinguished by distorted hydration features rather than distinct spectral features, indicating hydrated minerals but making unique identification difficult. In particular, it lacks features common to hydrated sulfate minerals, challenging the traditional view of an endogenous salty component dominated by Mg-sulfates. Chloride evaporite deposits are one possible alternative.

Interpersonal Subtypes Within Social Anxiety: The Identification of Distinct Social Features.

Science.gov (United States)

Cooper, Danielle; Anderson, Timothy

2017-10-05

Although social anxiety disorder is defined by anxiety-related symptoms, little research has focused on the interpersonal features of social anxiety. Prior studies (Cain, Pincus, & Grosse Holtforth, 2010; Kachin, Newman, & Pincus, 2001) identified distinct subgroups of socially anxious individuals' interpersonal circumplex problems that were blends of agency and communion, and yet inconsistencies remain. We predicted 2 distinct interpersonal subtypes would exist for individuals with high social anxiety, and that these social anxiety subtypes would differ on empathetic concern, paranoia, received peer victimization, perspective taking, and emotional suppression. From a sample of 175 undergraduate participants, 51 participants with high social anxiety were selected as above a clinical cutoff on the social phobia scale. Cluster analyses identified 2 interpersonal subtypes of socially anxious individuals: low hostility-high submissiveness (Cluster 1) and high hostility-high submissiveness (Cluster 2). Cluster 1 reported higher levels of empathetic concern, lower paranoia, less peer victimization, and lower emotional suppression compared to Cluster 2. There were no differences between subtypes on perspective taking or cognitive reappraisal. Findings are consistent with an interpersonal conceptualization of social anxiety, and provide evidence of distinct social features between these subtypes. Findings have implications for the etiology, classification, and treatment of social anxiety.

Are there distinctive indigenous methods of inquiry? | Le Grange ...

African Journals Online (AJOL)

This article explores whether there are methods that might be referred to as being distinctly indigenous. In doing so the nature of method is examined and it is concluded that method is not universal and neutral, but rather situated and performative. The upshot of this is that research methods can be transformed and that ...

Education and Training: Is There Any Longer a Useful Distinction?

Science.gov (United States)

Hager, Paul; Laurent, John

1990-01-01

Although education and training were distinct concepts when Taylorism dominated the workplace, it is no longer appropriate to separate them. Today's highly competitive environment requires the education of a flexible, multiskilled workforce, not training for narrowly defined employment tasks. (SK)

Parakeratosis pustulosa - a distinct but less familiar disease

Directory of Open Access Journals (Sweden)

Pandhi Deepika

2003-01-01

Full Text Available Parakeratosis pustulosa (PP is a distinct but less commonly known skin disease, which is frequently seen, in young girls. We describe the clinical and histological features of PP in a 7 month old female baby. Further, it is stressed that unless carefully looked for, this entity may be easily misdiagnosed as chronic paronychia, acrodermatitis of Hallopeau, pustular psoriasis, atopic dermatitis, tinea pedis or dry fissured eczematoid dermatitis and mistreated subsequently.

Replicating distinctive facial features in lineups: identification performance in young versus older adults.

Science.gov (United States)

Badham, Stephen P; Wade, Kimberley A; Watts, Hannah J E; Woods, Natalie G; Maylor, Elizabeth A

2013-04-01

Criminal suspects with distinctive facial features, such as tattoos or bruising, may stand out in a police lineup. To prevent suspects from being unfairly identified on the basis of their distinctive feature, the police often manipulate lineup images to ensure that all of the members appear similar. Recent research shows that replicating a distinctive feature across lineup members enhances eyewitness identification performance, relative to removing that feature on the target. In line with this finding, the present study demonstrated that with young adults (n = 60; mean age = 20), replication resulted in more target identifications than did removal in target-present lineups and that replication did not impair performance, relative to removal, in target-absent lineups. Older adults (n = 90; mean age = 74) performed significantly worse than young adults, identifying fewer targets and more foils; moreover, older adults showed a minimal benefit from replication over removal. This pattern is consistent with the associative deficit hypothesis of aging, such that older adults form weaker links between faces and their distinctive features. Although replication did not produce much benefit over removal for older adults, it was not detrimental to their performance. Therefore, the results suggest that replication may not be as beneficial to older adults as it is to young adults and demonstrate a new practical implication of age-related associative deficits in memory.

76 FR 9734 - Endangered and Threatened Species; Proposed Threatened Status for Distinct Population Segments of...

Science.gov (United States)

2011-02-22

... Population Segments of the Bearded Seal AGENCY: National Marine Fisheries Service (NMFS), National Oceanic... December 10, 2010, we, NMFS, published a proposed rule to list the Beringia and Okhotsk Distinct Population..., 2010 (75 FR 77476), we published a proposed rule to list the Beringia and Okhotsk Distinct Population...

A distinct bacterial dysbiosis associated skin inflammation in ovine footrot

Science.gov (United States)

Maboni, Grazieli; Blanchard, Adam; Frosth, Sara; Stewart, Ceri; Emes, Richard; Tötemeyer, Sabine

2017-03-01

Ovine footrot is a highly prevalent bacterial disease caused by Dichelobacter nodosus and characterised by the separation of the hoof horn from the underlying skin. The role of innate immune molecules and other bacterial communities in the development of footrot lesions remains unclear. This study shows a significant association between the high expression of IL1β and high D. nodosus load in footrot samples. Investigation of the microbial population identified distinct bacterial populations in the different disease stages and also depending on the level of inflammation. Treponema (34%), Mycoplasma (29%) and Porphyromonas (15%) were the most abundant genera associated with high levels of inflammation in footrot. In contrast, Acinetobacter (25%), Corynebacteria (17%) and Flavobacterium (17%) were the most abundant genera associated with high levels of inflammation in healthy feet. This demonstrates for the first time there is a distinct microbial community associated with footrot and high cytokine expression.

The True Self: A Psychological Concept Distinct From the Self.

Science.gov (United States)

Strohminger, Nina; Knobe, Joshua; Newman, George

2017-07-01

A long tradition of psychological research has explored the distinction between characteristics that are part of the self and those that lie outside of it. Recently, a surge of research has begun examining a further distinction. Even among characteristics that are internal to the self, people pick out a subset as belonging to the true self. These factors are judged as making people who they really are, deep down. In this paper, we introduce the concept of the true self and identify features that distinguish people's understanding of the true self from their understanding of the self more generally. In particular, we consider recent findings that the true self is perceived as positive and moral and that this tendency is actor-observer invariant and cross-culturally stable. We then explore possible explanations for these findings and discuss their implications for a variety of issues in psychology.

Recognition of distinctive patterns of gallium-67 distribution in sarcoidosis

International Nuclear Information System (INIS)

Sulavik, S.B.; Spencer, R.P.; Weed, D.A.; Shapiro, H.R.; Shiue, S.T.; Castriotta, R.J.

1990-01-01

Assessment of gallium-67 ( 67 Ga) uptake in the salivary and lacrimal glands and intrathoracic lymph nodes was made in 605 consecutive patients including 65 with sarcoidosis. A distinctive intrathoracic lymph node 67 Ga uptake pattern, resembling the Greek letter lambda, was observed only in sarcoidosis (72%). Symmetrical lacrimal gland and parotid gland 67 Ga uptake (panda appearance) was noted in 79% of sarcoidosis patients. A simultaneous lambda and panda pattern (62%) or a panda appearance with radiographic bilateral, symmetrical, hilar lymphadenopathy (6%) was present only in sarcoidosis patients. The presence of either of these patterns was particularly prevalent in roentgen Stages I (80%) or II (74%). We conclude that simultaneous (a) lambda and panda images, or (b) a panda image with bilateral symmetrical hilar lymphadenopathy on chest X-ray represent distinctive patterns which are highly specific for sarcoidosis, and may obviate the need for invasive diagnostic procedures

The influence of context on distinct facial expressions of disgust.

Science.gov (United States)

Reschke, Peter J; Walle, Eric A; Knothe, Jennifer M; Lopez, Lukas D

2018-06-11

Face perception is susceptible to contextual influence and perceived physical similarities between emotion cues. However, studies often use structurally homogeneous facial expressions, making it difficult to explore how within-emotion variability in facial configuration affects emotion perception. This study examined the influence of context on the emotional perception of categorically identical, yet physically distinct, facial expressions of disgust. Participants categorized two perceptually distinct disgust facial expressions, "closed" (i.e., scrunched nose, closed mouth) and "open" (i.e., scrunched nose, open mouth, protruding tongue), that were embedded in contexts comprising emotion postures and scenes. Results demonstrated that the effect of nonfacial elements was significantly stronger for "open" disgust facial expressions than "closed" disgust facial expressions. These findings provide support that physical similarity within discrete categories of facial expressions is mutable and plays an important role in affective face perception. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Anticancer Properties of Distinct Antimalarial Drug Classes

Science.gov (United States)

Hooft van Huijsduijnen, Rob; Guy, R. Kiplin; Chibale, Kelly; Haynes, Richard K.; Peitz, Ingmar; Kelter, Gerhard; Phillips, Margaret A.; Vennerstrom, Jonathan L.; Yuthavong, Yongyuth; Wells, Timothy N. C.

2013-01-01

We have tested five distinct classes of established and experimental antimalarial drugs for their anticancer potential, using a panel of 91 human cancer lines. Three classes of drugs: artemisinins, synthetic peroxides and DHFR (dihydrofolate reductase) inhibitors effected potent inhibition of proliferation with IC50s in the nM- low µM range, whereas a DHODH (dihydroorotate dehydrogenase) and a putative kinase inhibitor displayed no activity. Furthermore, significant synergies were identified with erlotinib, imatinib, cisplatin, dasatinib and vincristine. Cluster analysis of the antimalarials based on their differential inhibition of the various cancer lines clearly segregated the synthetic peroxides OZ277 and OZ439 from the artemisinin cluster that included artesunate, dihydroartemisinin and artemisone, and from the DHFR inhibitors pyrimethamine and P218 (a parasite DHFR inhibitor), emphasizing their shared mode of action. In order to further understand the basis of the selectivity of these compounds against different cancers, microarray-based gene expression data for 85 of the used cell lines were generated. For each compound, distinct sets of genes were identified whose expression significantly correlated with compound sensitivity. Several of the antimalarials tested in this study have well-established and excellent safety profiles with a plasma exposure, when conservatively used in malaria, that is well above the IC50s that we identified in this study. Given their unique mode of action and potential for unique synergies with established anticancer drugs, our results provide a strong basis to further explore the potential application of these compounds in cancer in pre-clinical or and clinical settings. PMID:24391728

Anticancer properties of distinct antimalarial drug classes.

Directory of Open Access Journals (Sweden)

Rob Hooft van Huijsduijnen

Full Text Available We have tested five distinct classes of established and experimental antimalarial drugs for their anticancer potential, using a panel of 91 human cancer lines. Three classes of drugs: artemisinins, synthetic peroxides and DHFR (dihydrofolate reductase inhibitors effected potent inhibition of proliferation with IC50s in the nM- low µM range, whereas a DHODH (dihydroorotate dehydrogenase and a putative kinase inhibitor displayed no activity. Furthermore, significant synergies were identified with erlotinib, imatinib, cisplatin, dasatinib and vincristine. Cluster analysis of the antimalarials based on their differential inhibition of the various cancer lines clearly segregated the synthetic peroxides OZ277 and OZ439 from the artemisinin cluster that included artesunate, dihydroartemisinin and artemisone, and from the DHFR inhibitors pyrimethamine and P218 (a parasite DHFR inhibitor, emphasizing their shared mode of action. In order to further understand the basis of the selectivity of these compounds against different cancers, microarray-based gene expression data for 85 of the used cell lines were generated. For each compound, distinct sets of genes were identified whose expression significantly correlated with compound sensitivity. Several of the antimalarials tested in this study have well-established and excellent safety profiles with a plasma exposure, when conservatively used in malaria, that is well above the IC50s that we identified in this study. Given their unique mode of action and potential for unique synergies with established anticancer drugs, our results provide a strong basis to further explore the potential application of these compounds in cancer in pre-clinical or and clinical settings.

Anti-triatomine saliva immunoassays for the evaluation of impregnated netting trials against Chagas disease transmission

Czech Academy of Sciences Publication Activity Database

Schwarz, Alexandra; Juarez, J. A.; Richards, J.; Rath, B.; Machaca, V. Q.; Castro, Y. E.; Málaga, E. S.; Levy, K.; Gilman, R. H.; Bern, C.; Verastegui, M.; Levy, M. Z.

2011-01-01

Roč. 41, č. 6 (2011), s. 591-594 ISSN 0020-7519 R&D Projects: GA ČR GPP302/11/P798 Institutional research plan: CEZ:AV0Z60220518 Keywords : Triatoma infestans * Impregnated net * Sentinel guinea pig * Saliva * Antibody response Subject RIV: EC - Immunology Impact factor: 3.393, year: 2011

Group Frames With Few Distinct Inner Products and Low Coherence

KAUST Repository

Thill, Matthew

2015-10-01

Frame theory has been a popular subject in the design of structured signals and codes in recent years, with applications ranging from the design of measurement matrices in compressive sensing, to spherical codes for data compression and data transmission, to spacetime codes for MIMO communications, and to measurement operators in quantum sensing. High-performance codes usually arise from designing frames whose elements have mutually low coherence. Building off the original “group frame” design of Slepian which has since been elaborated in the works of Vale and Waldron, we present several new frame constructions based on cyclic and generalized dihedral groups. Slepian\\'s original construction was based on the premise that group structure allows one to reduce the number of distinct inner pairwise inner products in a frame with n elements from [(n(n-1))/2] to n-1. All of our constructions further utilize the group structure to produce tight frames with even fewer distinct inner product values between the frame elements. When n is prime, for example, we use cyclic groups to construct m-dimensional frame vectors with at most [(n-1)/m] distinct inner products. We use this behavior to bound the coherence of our frames via arguments based on the frame potential, and derive even tighter bounds from combinatorial and algebraic arguments using the group structure alone. In certain cases, we recover well-known Welch bound achieving frames. In cases where the Welch bound has not been achieved, and is not known to be achievable, we obtain frames with close to Welch bound performance.

Spatial and Single-Cell Transcriptional Profiling Identifies Functionally Distinct Human Dermal Fibroblast Subpopulations.

Science.gov (United States)

Philippeos, Christina; Telerman, Stephanie B; Oulès, Bénédicte; Pisco, Angela O; Shaw, Tanya J; Elgueta, Raul; Lombardi, Giovanna; Driskell, Ryan R; Soldin, Mark; Lynch, Magnus D; Watt, Fiona M

2018-04-01

Previous studies have shown that mouse dermis is composed of functionally distinct fibroblast lineages. To explore the extent of fibroblast heterogeneity in human skin, we used a combination of comparative spatial transcriptional profiling of human and mouse dermis and single-cell transcriptional profiling of human dermal fibroblasts. We show that there are at least four distinct fibroblast populations in adult human skin, not all of which are spatially segregated. We define markers permitting their isolation and show that although marker expression is lost in culture, different fibroblast subpopulations retain distinct functionality in terms of Wnt signaling, responsiveness to IFN-γ, and ability to support human epidermal reconstitution when introduced into decellularized dermis. These findings suggest that ex vivo expansion or in vivo ablation of specific fibroblast subpopulations may have therapeutic applications in wound healing and diseases characterized by excessive fibrosis. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Articulatory Distinctiveness of Vowels and Consonants: A Data-Driven Approach

Science.gov (United States)

Wang, Jun; Green, Jordan R.; Samal, Ashok; Yunusova, Yana

2013-01-01

Purpose: To quantify the articulatory distinctiveness of 8 major English vowels and 11 English consonants based on tongue and lip movement time series data using a data-driven approach. Method: Tongue and lip movements of 8 vowels and 11 consonants from 10 healthy talkers were

Conceptual distinctiveness supports detailed visual long-term memory for real-world objects.

Science.gov (United States)

Konkle, Talia; Brady, Timothy F; Alvarez, George A; Oliva, Aude

2010-08-01

Humans have a massive capacity to store detailed information in visual long-term memory. The present studies explored the fidelity of these visual long-term memory representations and examined how conceptual and perceptual features of object categories support this capacity. Observers viewed 2,800 object images with a different number of exemplars presented from each category. At test, observers indicated which of 2 exemplars they had previously studied. Memory performance was high and remained quite high (82% accuracy) with 16 exemplars from a category in memory, demonstrating a large memory capacity for object exemplars. However, memory performance decreased as more exemplars were held in memory, implying systematic categorical interference. Object categories with conceptually distinctive exemplars showed less interference in memory as the number of exemplars increased. Interference in memory was not predicted by the perceptual distinctiveness of exemplars from an object category, though these perceptual measures predicted visual search rates for an object target among exemplars. These data provide evidence that observers' capacity to remember visual information in long-term memory depends more on conceptual structure than perceptual distinctiveness. 2010 APA, all rights reserved

Genetic approach identifies distinct asthma pathways in overweight vs normal weight children.

Science.gov (United States)

Butsch Kovacic, M; Martin, L J; Biagini Myers, J M; He, H; Lindsey, M; Mersha, T B; Khurana Hershey, G K

2015-08-01

The pathogenesis of asthma in the context of excess body weight may be distinct from asthma that develops in normal weight children. The study's objective was to explore the biology of asthma in the context of obesity and normal weight status using genetic methodologies. Associations between asthma and SNPs in 49 genes were assessed, as well as, interactions between SNPs and overweight status in child participants of the Greater Cincinnati Pediatric Clinic Repository. Asthma was significantly associated with weight (OR = 1.38; P = 0.037). The number of genes and the magnitude of their associations with asthma were notably greater when considering overweight children alone vs normal weight and overweight children together. When considering weight, distinct sets of asthma-associated genes were observed, many times with opposing effects. We demonstrated that the underlying heterogeneity of asthma is likely due in part to distinct pathogenetic pathways that depend on preceding/comorbid overweight and/or allergy. It is therefore important to consider both obesity and asthma when conducting studies of asthma. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The mechanism of the emergence of distinct overstretched DNA states

Energy Technology Data Exchange (ETDEWEB)

Zhu, You-Liang; Sun, Zhao-Yan, E-mail: zysun@ciac.ac.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Lu, Zhong-Yuan [State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry, Jilin University, Changchun 130023 (China)

2016-01-14

Although multiple overstretched DNA states were identified in experiments, the mechanism of the emergence of distinct states is still unclear. Molecular dynamics simulation is an ideal tool to clarify the mechanism, but the force loading rates in stretching achieved by conventional all-atom DNA models are much faster, which essentially affect overstretching states. We employed a modified coarse-grained DNA model with an unprecedented low loading rate in simulations to study the overstretching transitions of end-opened double-stranded DNA. We observed two-strand peeling off for DNA with low stability and the S-DNA with high stability under tension. By introducing a melting-forbidden model which prevents base-pair breaking, we still observed the overstretching transition induced by the formation of S-DNA due to the change of dihedral angle. Hence, we confirmed that the competition between the two strain-softening manners, i.e., base-pair breaking and dihedral angle variation, results in the emergence of distinct overstretched DNA states.

Doença de Chagas no Brasil Chagas disease in Brazil

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Márcio C. Vinhaes

2000-01-01

Full Text Available Sumariam-se os dados da Fundação Nacional de Saúde (FNS sobre o estado atual dos vetores da doença de Chagas no Brasil, verificando-se que após vinte anos de controle químico continuado houve franca redução dos índices triatomínico-tripanosômicos, particularmente para esp��cies como Triatoma infestans e Panstrongylus megistus. Em paralelo, dados de sorologia escolar, de internações e de mortalidade pela doença indicam descenso nas taxas de incidência e impacto médico social da protozoose, restando áreas mais preocupantes, como o Nordeste e resíduos de T. infestans. Impõe-se urgente uma vigilância epidemiológica efetiva, a ser realizada por estados e municípios ante o processo de descentralização da FNS.This article presents the current situation for Chagas disease vectors in Brazil, based on data from the Brazilian National Health Foundation (FNS. Over the course of the last 20 years, continuous chemical control has resulted in a clear reduction of triatomine densities and Trypanosoma cruzi in Brazilian dwellings. Results have been particularly promising in relation to Triatoma infestans and Panstrongylus megistus, considered the most important species in the past. In parallel, data from school serological surveys, hospitalized patients, and mortality records show an important decrease in the disease. Nevertheless, some areas of the Brazilian Northeast and some residual foci of Triatoma infestans and Panstrongylus megistus remain as major challenges for public health authorities, requiring effective epidemiological surveillance. States and municipalities are required to assume this task at present, as the traditional Brazilian National Health Foundation is undergoing decentralization.

Motivation to hide emotion and children's understanding of the distinction between real and apparent emotions.

Science.gov (United States)

Gosselin, Pierre; Warren, Madeleine; Diotte, Michèle

2002-12-01

The authors investigated the extent to which children's understanding of the distinction between real and apparent emotions varied according to the motivation to hide emotions. Children, aged 6-7 and 10-11 years, were read stories designed to elicit either prosocial or self-protective motivated display rules and were asked to predict the facial expressions the protagonists would make to hide felt emotions. Children were found to understand the distinction between real and apparent emotions very well, independently of the type of motivation. Contrary to predictions, boys understood this distinction better than did girls when the motivation to hide positive emotions was prosocial. Children perceived neutralization as the most appropriate strategy to hide felt emotions, followed by masking.

Branchial Cilia and Sperm Flagella Recruit Distinct Axonemal Components

Science.gov (United States)

Konno, Alu; Shiba, Kogiku; Cai, Chunhua; Inaba, Kazuo

2015-01-01

Eukaryotic cilia and flagella have highly conserved 9 + 2 structures. They are functionally diverged to play cell-type-specific roles even in a multicellular organism. Although their structural components are therefore believed to be common, few studies have investigated the molecular diversity of the protein components of the cilia and flagella in a single organism. Here we carried out a proteomic analysis and compared protein components between branchial cilia and sperm flagella in a marine invertebrate chordate, Ciona intestinalis. Distinct feature of protein recruitment in branchial cilia and sperm flagella has been clarified; (1) Isoforms of α- and β-tubulins as well as those of actins are distinctly used in branchial cilia or sperm flagella. (2) Structural components, such as dynein docking complex, tektins and an outer dense fiber protein, are used differently by the cilia and flagella. (3) Sperm flagella are specialized for the cAMP- and Ca2+-dependent regulation of outer arm dynein and for energy metabolism by glycolytic enzymes. Our present study clearly demonstrates that flagellar or ciliary proteins are properly recruited according to their function and stability, despite their apparent structural resemblance and conservation. PMID:25962172

Using the Ubiquitin-modified Proteome to Monitor Distinct and Spatially Restricted Protein Homeostasis Dysfunction.

Science.gov (United States)

Gendron, Joshua M; Webb, Kristofor; Yang, Bing; Rising, Lisa; Zuzow, Nathan; Bennett, Eric J

2016-08-01

Protein homeostasis dysfunction has been implicated in the development and progression of aging related human pathologies. There is a need for the establishment of quantitative methods to evaluate global protein homoeostasis function. As the ubiquitin (ub) proteasome system plays a key role in regulating protein homeostasis, we applied quantitative proteomic methods to evaluate the sensitivity of site-specific ubiquitylation events as markers for protein homeostasis dysfunction. Here, we demonstrate that the ub-modified proteome can exceed the sensitivity of engineered fluorescent reporters as a marker for proteasome dysfunction and can provide unique signatures for distinct proteome challenges which is not possible with engineered reporters. We demonstrate that combining ub-proteomics with subcellular fractionation can effectively separate degradative and regulatory ubiquitylation events on distinct protein populations. Using a recently developed potent inhibitor of the critical protein homeostasis factor p97/VCP, we demonstrate that distinct insults to protein homeostasis function can elicit robust and largely unique alterations to the ub-modified proteome. Taken together, we demonstrate that proteomic approaches to monitor the ub-modified proteome can be used to evaluate global protein homeostasis and can be used to monitor distinct functional outcomes for spatially separated protein populations. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

77 FR 71396 - Humboldt-Toiyabe National Forest; Nevada and California Greater Sage Grouse Bi-State Distinct...

Science.gov (United States)

2012-11-30

... Greater Sage Grouse Bi-State Distinct Population Segment Forest Plan Amendment Environmental Impact... Sage Grouse Bi- State Distinct Population Segment. DATES: Comments concerning the scope of the analysis..., but precluded'' Endangered Species Act (ESA) listing petition decision for the Greater Sage grouse Bi...

Chemically different non-thermal plasmas target distinct cell death pathways

Czech Academy of Sciences Publication Activity Database

Lunov, O.; Zablotskyy, V.; Chrupina, O.; Lunova, M.; Jirsa, M.; Dejneka, A.; Kubinová, Šárka

2017-01-01

Roč. 7, apr (2017), s. 600 ISSN 2045-2322 R&D Projects: GA MŠk(CZ) LO1309 Institutional support: RVO:68378041 Keywords : chemically different * non-thermal plasmas * target distinct cell death pathways Subject RIV: FP - Other Medical Disciplines OBOR OECD: Biophysics Impact factor: 4.259, year: 2016

45 CFR 91.18 - Age distinctions contained in HHS regulations.

Science.gov (United States)

2010-10-01

....18 Section 91.18 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION... distinctions contained in a rule or regulation issued by HHS shall be presumed to be necessary to the achievement of a statutory objective of the program or activity to which the rule or regulation applies...

Primeira evidência de Trypanosoma rangeli no sudeste do Brasil, região endêmica para doença de Chagas First evidence of Trypanosoma rangeli in the southeast of Brazil, an endemic region to Chagas' disease

Directory of Open Access Journals (Sweden)

Luis Eduardo Ramirez

1998-02-01

Full Text Available Informa-se, pela primeira vez, os achados de Trypanosoma rangeli no Triângulo Mineiro, Sudeste do Brasil, área altamente endêmica para doença de Chagas, assim como a infecção natural da espécie Didelphis albiventris.com este mesmo tripanosoma. Estes foram demonstrados por esfregaços sangüíneos, xenodiagnóstico, hemocultura, microhematócrito e PCR. A PCR foi realizada nas fezes e hemolinfa de Triatoma infestans, usando como controle cepas de T. rangeli provenientes da Colômbia.This short communication informs the discovery of Trypanosoma rangeli for the first time at Triângulo Mineiro region, South-east of Brazil, a highly endemic area of Chagas'disease and also the natural infection of Didelphis albiventris with the same trypanosome. Both the findings were demonstrated through blood smears, xenodiagnosis, microhematocrit technics and PCR. The last one was realized in faeces and hemolymph of Triatoma infestans utilizing as controls strains of T. rangeli from Colombia.

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

Directory of Open Access Journals (Sweden)

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.

Neurophysiological Distinction between Schizophrenia and Schizoaffective Disorder

Science.gov (United States)

Mathalon, Daniel H.; Hoffman, Ralph E.; Watson, Todd D.; Miller, Ryan M.; Roach, Brian J.; Ford, Judith M.

2009-01-01

Schizoaffective disorder (SA) is distinguished from schizophrenia (SZ) based on the presence of prominent mood symptoms over the illness course. Despite this clinical distinction, SA and SZ patients are often combined in research studies, in part because data supporting a distinct pathophysiological boundary between the disorders are lacking. Indeed, few studies have addressed whether neurobiological abnormalities associated with SZ, such as the widely replicated reduction and delay of the P300 event-related potential (ERP), are also present in SA. Scalp EEG was acquired from patients with DSM-IV SA (n = 15) or SZ (n = 22), as well as healthy controls (HC; n = 22) to assess the P300 elicited by infrequent target (15%) and task-irrelevant distractor (15%) stimuli in separate auditory and visual ”oddball” tasks. P300 amplitude was reduced and delayed in SZ, relative to HC, consistent with prior studies. These SZ abnormalities did not interact with stimulus type (target vs. task-irrelevant distractor) or modality (auditory vs. visual). Across sensory modality and stimulus type, SA patients exhibited normal P300 amplitudes (significantly larger than SZ patients and indistinguishable from HC). However, P300 latency and reaction time were both equivalently delayed in SZ and SA patients, relative to HC. P300 differences between SA and SZ patients could not be accounted for by variation in symptom severity, socio-economic status, education, or illness duration. Although both groups show similar deficits in processing speed, SA patients do not exhibit the P300 amplitude deficits evident in SZ, consistent with an underlying pathophysiological boundary between these disorders. PMID:20140266

50 CFR 226.217 - Critical habitat for the Gulf of Maine Distinct Population Segment of Atlantic Salmon (Salmo salar).

Science.gov (United States)

2010-10-01

... Distinct Population Segment of Atlantic Salmon (Salmo salar). 226.217 Section 226.217 Wildlife and... Distinct Population Segment of Atlantic Salmon (Salmo salar). Critical habitat is designated to include all... the Gulf of Maine Distinct Population Segment of Atlantic Salmon (GOM DPS), except for those...

Rhinovirus infection induces distinct transcriptome profiles in polarized human macrophages.

Science.gov (United States)

Rajput, Charu; Walsh, Megan P; Eder, Breanna N; Metitiri, Ediri E; Popova, Antonia P; Hershenson, Marc B

2018-05-01

Infections with rhinovirus (RV) cause asthma exacerbations. Recent studies suggest that macrophages play a role in asthmatic airway inflammation and the innate immune response to RV infection. Macrophages exhibit phenotypes based on surface markers and gene expression. We hypothesized that macrophage polarization state alters gene expression in response to RV infection. Cells were derived from human peripheral blood derived monocytes. M1 and M2 polarization was carried out by using IFN-γ and IL-4, respectively, and RNA was extracted for Affymetrix Human Gene ST2.1 exon arrays. Selected genes were validated by quantitative (q)PCR. Treatment of nonactivated (M0) macrophages with IFN-γ and IL-4 induced the expression of 252 and 153 distinct genes, respectively, including previously-identified M1 and M2 markers. RV infection of M0 macrophages induced upregulation of 232 genes; pathway analysis showed significant overrepresentation of genes involved in IFN-α/β signaling and cytokine signaling in the immune system. RV infection induced differential expression of 195 distinct genes in M1-like macrophages but only seven distinct genes in M2-like-polarized cells. In a secondary analysis, comparison between M0-, RV-infected, and M1-like-polarized, RV-infected macrophages revealed differential expression of 227 genes including those associated with asthma and its exacerbation. qPCR demonstrated increased expression of CCL8, CXCL10, TNFSF10, TNFSF18, IL6, NOD2, and GSDMD and reduced expression of VNN1, AGO1, and AGO2. Together, these data show that, in contrast to M2-like-polarized macrophages, gene expression of M1-like macrophages is highly regulated by RV.

37 CFR 2.41 - Proof of distinctiveness under section 2(f).

Science.gov (United States)

2010-07-01

... mark may be accepted as prima facie evidence of distinctiveness. Also, if the mark is said to have... with § 2.20, in the application may, in appropriate cases, be accepted as prima facie evidence of...

A distinction of two discourses concerning wellbeing

DEFF Research Database (Denmark)

Wistoft, Karen; Qvortrup, Lars

2017-01-01

and behavioral mental health interventions, while the latter defines wellbeing in positive terms with a focus on wellbeing as the result of learning and with pedagogical interventions that only indirectly can support the individual’s learning activity. The former sees wellbeing as the result of a “wellbeing cure......The article concerns the current discourses concerning well-being with the point that it is important to make a distinction between a healthcare oriented discourse and a learning oriented discourse. The former defines wellbeing in negative terms and looks at causally oriented aspects of wellbeing......”, while the latter sees wellbeing as the result of wellbeing learning processes....

Peptidomic and transcriptomic profiling of four distinct spider venoms.

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Vera Oldrati

Full Text Available Venom based research is exploited to find novel candidates for the development of innovative pharmacological tools, drug candidates and new ingredients for cosmetic and agrochemical industries. Moreover, venomics, as a well-established approach in systems biology, helps to elucidate the genetic mechanisms of the production of such a great molecular biodiversity. Today the advances made in the proteomics, transcriptomics and bioinformatics fields, favor venomics, allowing the in depth study of complex matrices and the elucidation even of minor compounds present in minute biological samples. The present study illustrates a rapid and efficient method developed for the elucidation of venom composition based on NextGen mRNA sequencing of venom glands and LC-MS/MS venom proteome profiling. The analysis of the comprehensive data obtained was focused on cysteine rich peptide toxins from four spider species originating from phylogenetically distant families for comparison purposes. The studied species were Heteropoda davidbowie (Sparassidae, Poecilotheria formosa (Theraphosidae, Viridasius fasciatus (Viridasiidae and Latrodectus mactans (Theridiidae. This led to a high resolution profiling of 284 characterized cysteine rich peptides, 111 of which belong to the Inhibitor Cysteine Knot (ICK structural motif. The analysis of H. davidbowie venom revealed a high richness in term of venom diversity: 95 peptide sequences were identified; out of these, 32 peptides presented the ICK structural motif and could be classified in six distinct families. The profiling of P. formosa venom highlighted the presence of 126 peptide sequences, with 52 ICK toxins belonging to three structural distinct families. V. fasciatus venom was shown to contain 49 peptide sequences, out of which 22 presented the ICK structural motif and were attributed to five families. The venom of L. mactans, until now studied for its large neurotoxins (Latrotoxins, revealed the presence of 14

Differential Recruitment of Distinct Amygdalar Nuclei across Appetitive Associative Learning

Science.gov (United States)

Cole, Sindy; Powell, Daniel J.; Petrovich, Gorica D.

2013-01-01

The amygdala is important for reward-associated learning, but how distinct cell groups within this heterogeneous structure are recruited during appetitive learning is unclear. Here we used Fos induction to map the functional amygdalar circuitry recruited during early and late training sessions of Pavlovian appetitive conditioning. We found that a…

A Distinct Population of Microglia Supports Adult Neurogenesis in the Subventricular Zone

DEFF Research Database (Denmark)

Ribeiro Xavier, Anna L.; Kress, Benjamin T.; Goldman, Steven A.

2015-01-01

found that microglia residing in the SVZ and adjacent rostral migratory stream (RMS) comprise a morphologically and antigenically distinct phenotype of immune effectors. Whereas exhibiting characteristics of alternatively activated microglia, the SVZ/RMS microglia were clearly distinguished by their low...... STATEMENT: Microglial cells are a specialized population of macrophages in the CNS, playing key roles as immune mediators. As integral components in the CNS, the microglia stand out for using the same mechanisms, phagocytosis and cytochemokine release, to promote homeostasis, synaptic pruning, and neural...... toward olfactory bulb layers. In addition to other unique populations residing in the SVZ niche, microglia display distinct morphofunctional properties that boost neuronal progenitor survival and migration in the mammalian brain....

Abstract and Effector-Selective Decision Signals Exhibit Qualitatively Distinct Dynamics before Delayed Perceptual Reports.

Science.gov (United States)

Twomey, Deirdre M; Kelly, Simon P; O'Connell, Redmond G

2016-07-13

Electrophysiological research has isolated neural signatures of decision formation in a variety of brain regions. Studies in rodents and monkeys have focused primarily on effector-selective signals that translate the emerging decision into a specific motor plan, but, more recently, research on the human brain has identified an abstract signature of evidence accumulation that does not appear to play any direct role in action preparation. The functional dissociations between these distinct signal types have only begun to be characterized, and their dynamics during decisions with deferred actions with or without foreknowledge of stimulus-effector mapping, a commonly studied task scenario in single-unit and functional imaging investigations, have not been established. Here we traced the dynamics of distinct abstract and effector-selective decision signals in the form of the broad-band centro-parietal positivity (CPP) and limb-selective β-band (8-16 and 18-30 Hz) EEG activity, respectively, during delayed-reported motion direction decisions with and without foreknowledge of direction-response mapping. With foreknowledge, the CPP and β-band signals exhibited a similar gradual build-up following evidence onset, but whereas choice-predictive β-band activity persisted up until the delayed response, the CPP dropped toward baseline after peaking. Without foreknowledge, the CPP exhibited identical dynamics, whereas choice-selective β-band activity was eliminated. These findings highlight qualitative functional distinctions between effector-selective and abstract decision signals and are of relevance to the assumptions founding functional neuroimaging investigations of decision-making. Neural signatures of evidence accumulation have been isolated in numerous brain regions. Although animal neurophysiology has largely concentrated on effector-selective decision signals that translate the emerging decision into a specific motor plan, recent research on the human brain has

Urbanization, land tenure security and vector-borne Chagas disease

Science.gov (United States)

Levy, Michael Z.; Barbu, Corentin M.; Castillo-Neyra, Ricardo; Quispe-Machaca, Victor R.; Ancca-Juarez, Jenny; Escalante-Mejia, Patricia; Borrini-Mayori, Katty; Niemierko, Malwina; Mabud, Tarub S.; Behrman, Jere R.; Naquira-Velarde, Cesar

2014-01-01

Modern cities represent one of the fastest growing ecosystems on the planet. Urbanization occurs in stages; each stage characterized by a distinct habitat that may be more or less susceptible to the establishment of disease vector populations and the transmission of vector-borne pathogens. We performed longitudinal entomological and epidemiological surveys in households along a 1900 × 125 m transect of Arequipa, Peru, a major city of nearly one million inhabitants, in which the transmission of Trypanosoma cruzi, the aetiological agent of Chagas disease, by the insect vector Triatoma infestans, is an ongoing problem. The transect spans a cline of urban development from established communities to land invasions. We find that the vector is tracking the development of the city, and the parasite, in turn, is tracking the dispersal of the vector. New urbanizations are free of vector infestation for decades. T. cruzi transmission is very recent and concentrated in more established communities. The increase in land tenure security during the course of urbanization, if not accompanied by reasonable and enforceable zoning codes, initiates an influx of construction materials, people and animals that creates fertile conditions for epidemics of some vector-borne diseases. PMID:24990681

Distinct retrosplenial cortex cell populations and their spike dynamics during ketamine-induced unconscious state.

Directory of Open Access Journals (Sweden)

Grace E Fox

Full Text Available Ketamine is known to induce psychotic-like symptoms, including delirium and visual hallucinations. It also causes neuronal damage and cell death in the retrosplenial cortex (RSC, an area that is thought to be a part of high visual cortical pathways and at least partially responsible for ketamine's psychotomimetic activities. However, the basic physiological properties of RSC cells as well as their response to ketamine in vivo remained largely unexplored. Here, we combine a computational method, the Inter-Spike Interval Classification Analysis (ISICA, and in vivo recordings to uncover and profile excitatory cell subtypes within layers 2&3 and 5&6 of the RSC in mice within both conscious, sleep, and ketamine-induced unconscious states. We demonstrate two distinct excitatory principal cell sub-populations, namely, high-bursting excitatory principal cells and low-bursting excitatory principal cells, within layers 2&3, and show that this classification is robust over the conscious states, namely quiet awake, and natural unconscious sleep periods. Similarly, we provide evidence of high-bursting and low-bursting excitatory principal cell sub-populations within layers 5&6 that remained distinct during quiet awake and sleep states. We further examined how these subtypes are dynamically altered by ketamine. During ketamine-induced unconscious state, these distinct excitatory principal cell subtypes in both layer 2&3 and layer 5&6 exhibited distinct dynamics. We also uncovered different dynamics of local field potential under various brain states in layer 2&3 and layer 5&6. Interestingly, ketamine administration induced high gamma oscillations in layer 2&3 of the RSC, but not layer 5&6. Our results show that excitatory principal cells within RSC layers 2&3 and 5&6 contain multiple physiologically distinct sub-populations, and they are differentially affected by ketamine.

Distinctively human motivation and another view on human evolution

OpenAIRE

Prudkov, Pavel N.

2006-01-01

Human evolution is a multidisciplinary problem, one of its aspects is the origin and development of distinctively human psychological features. Cognitive properties (language, symbolic thinking) are considered as such features and numerous authors hypothesize its evolution. We suggest that the most important human characteristic is connected with motivation rather than cognition; this is the ability to construct and maintain long-term goal-directed processes having no biological basis. Once...

Distinctive tropical forest variants have unique soil microbial communities, but not always low microbial diversity

Directory of Open Access Journals (Sweden)

Binu M Tripathi

2016-04-01

Full Text Available There has been little study of whether different variants of tropical rainforest have distinct soil microbial communities and levels of diversity. We compared bacterial and fungal community composition and diversity between primary mixed dipterocarp, secondary mixed dipterocarp, white sand heath, inland heath, and peat swamp forests in Brunei Darussalam, northwest Borneo by analyzing Illumina Miseq sequence data of 16S rRNA gene and ITS1 region. We hypothesized that white sand heath, inland heath and peat swamp forests would show lower microbial diversity and relatively distinct microbial communities (compared to MDF primary and secondary forests due to their distinctive environments. We found that soil properties together with bacterial and fungal communities varied significantly between forest types. Alpha and beta-diversity of bacteria was highest in secondary dipterocarp and white sand heath forests. Also, bacterial alpha diversity was strongly structured by pH, adding another instance of this widespread pattern in nature. The alpha diversity of fungi was equally high in all forest types except peat swamp forest, although fungal beta-diversity was highest in primary and secondary mixed dipterocarp forests. The relative abundance of ectomycorrhizal (EcM fungi varied significantly between forest types, with highest relative abundance observed in MDF primary forest. Overall, our results suggest that the soil bacterial and fungal communities in these forest types are to a certain extent predictable and structured by soil properties, but that diversity is not determined by how distinctive the conditions are. This contrasts with the diversity patterns seen in rainforest trees, where distinctive soil conditions have consistently lower tree diversity.

Legal distinction between employee and independent contractor as applied to collective bargaining activities in timber harvesting

Science.gov (United States)

James E. Granskog; William C. Siegal

1977-01-01

Collective bargaining attempts by timber harvesting labor groups is often complicated by lack of a clear legal distinction between "employees" and "independent contractors." the primary criterion to make the distinction - the "right-to-control" test of common law - has now been amplified by a number of secondary tests, including: 1) the...

BARE retrotransposons are translated and replicated via distinct RNA pools.

Directory of Open Access Journals (Sweden)

Wei Chang

Full Text Available The replication of Long Terminal Repeat (LTR retrotransposons, which can constitute over 80% of higher plant genomes, resembles that of retroviruses. A major question for retrotransposons and retroviruses is how the two conflicting roles of their transcripts, in translation and reverse transcription, are balanced. Here, we show that the BARE retrotransposon, despite its organization into just one open reading frame, produces three distinct classes of transcripts. One is capped, polyadenylated, and translated, but cannot be copied into cDNA. The second is not capped or polyadenylated, but is destined for packaging and ultimate reverse transcription. The third class is capped, polyadenylated, and spliced to favor production of a subgenomic RNA encoding only Gag, the protein forming virus-like particles. Moreover, the BARE2 subfamily, which cannot synthesize Gag and is parasitic on BARE1, does not produce the spliced sub-genomic RNA for translation but does make the replication competent transcripts, which are packaged into BARE1 particles. To our knowledge, this is first demonstration of distinct RNA pools for translation and transcription for any retrotransposon.

The uses and abuses of the coherence – correspondence distinction

Science.gov (United States)

Polonioli, Andrea

2015-01-01

Kenneth Hammond introduced a distinction between coherence and correspondence criteria of rationality as a tool in the study of judgment and decision-making. This distinction has been widely used in the field. Yet, as this paper seeks to show, the relevant notions of coherence and correspondence have been progressively considered to be too narrow and have undergone non-trivial conceptual changes since their original introduction. I try to show, first, that the proliferation of conceptualizations of coherence and correspondence has created confusion in the literature and that appealing to such notions has not helped to elucidate discussions over the nature of rational judgment and decision-making. Nevertheless, I also argue for a reframing of the debate. In fact, what seems to underlie several contemporary appeals to the notions of coherence and correspondence is best explained in terms of a contrast between what I call rule-based and goal-based rationality. Whilst these categories do need further refinement, they do seem to be useful for organizing and understanding research on rational judgment and decision-making. PMID:25983700

Two Distinct Scene-Processing Networks Connecting Vision and Memory.

Science.gov (United States)

Baldassano, Christopher; Esteva, Andre; Fei-Fei, Li; Beck, Diane M

2016-01-01

A number of regions in the human brain are known to be involved in processing natural scenes, but the field has lacked a unifying framework for understanding how these different regions are organized and interact. We provide evidence from functional connectivity and meta-analyses for a new organizational principle, in which scene processing relies upon two distinct networks that split the classically defined parahippocampal place area (PPA). The first network of strongly connected regions consists of the occipital place area/transverse occipital sulcus and posterior PPA, which contain retinotopic maps and are not strongly coupled to the hippocampus at rest. The second network consists of the caudal inferior parietal lobule, retrosplenial complex, and anterior PPA, which connect to the hippocampus (especially anterior hippocampus), and are implicated in both visual and nonvisual tasks, including episodic memory and navigation. We propose that these two distinct networks capture the primary functional division among scene-processing regions, between those that process visual features from the current view of a scene and those that connect information from a current scene view with a much broader temporal and spatial context. This new framework for understanding the neural substrates of scene-processing bridges results from many lines of research, and makes specific functional predictions.

Approaching the Distinction between Intuition and Insight.

Science.gov (United States)

Zhang, Zhonglu; Lei, Yi; Li, Hong

2016-01-01

Intuition and insight share similar cognitive and neural basis. Though, there are still some essential differences between the two. Here in this short review, we discriminated between intuition, and insight in two aspects. First, intuition, and insight are toward different aspects of information processing. Whereas intuition involves judgment about "yes or no," insight is related to "what" is the solution. Second, tacit knowledge play different roles in between intuition and insight. On the one hand, tacit knowledge is conducive to intuitive judgment. On the other hand, tacit knowledge may first impede but later facilitate insight occurrence. Furthermore, we share theoretical, and methodological views on how to access the distinction between intuition and insight.

Distinct kinetics of serine and threonine dephosphorylation are essential for mitosis

DEFF Research Database (Denmark)

Hein, Jamin B; Hertz, Emil P T; Garvanska, Dimitriya H

2017-01-01

Protein phosphatase 2A (PP2A) in complex with B55 regulatory subunits reverses cyclin-dependent kinase 1 (Cdk1) phosphorylations at mitotic exit. Interestingly, threonine and serine residues phosphorylated by Cdk1 display distinct phosphorylation dynamics, but the biological significance remains ...

Phylogeographic Evidence for 2 Genetically Distinct Zoonotic Plasmodium knowlesi Parasites, Malaysia.

Science.gov (United States)

Yusof, Ruhani; Ahmed, Md Atique; Jelip, Jenarun; Ngian, Hie Ung; Mustakim, Sahlawati; Hussin, Hani Mat; Fong, Mun Yik; Mahmud, Rohela; Sitam, Frankie Anak Thomas; Japning, J Rovie-Ryan; Snounou, Georges; Escalante, Ananias A; Lau, Yee Ling

2016-08-01

Infections of humans with the zoonotic simian malaria parasite Plasmodium knowlesi occur throughout Southeast Asia, although most cases have occurred in Malaysia, where P. knowlesi is now the dominant malaria species. This apparently skewed distribution prompted an investigation of the phylogeography of this parasite in 2 geographically separated regions of Malaysia, Peninsular Malaysia and Malaysian Borneo. We investigated samples collected from humans and macaques in these regions. Haplotype network analyses of sequences from 2 P. knowlesi genes, type A small subunit ribosomal 18S RNA and cytochrome c oxidase subunit I, showed 2 genetically distinct divergent clusters, 1 from each of the 2 regions of Malaysia. We propose that these parasites represent 2 distinct P. knowlesi types that independently became zoonotic. These types would have evolved after the sea-level rise at the end of the last ice age, which separated Malaysian Borneo from Peninsular Malaysia.

Chemically different non-thermal plasmas target distinct cell death pathways

Czech Academy of Sciences Publication Activity Database

Lunov, Oleg; Zablotskyy, Vitaliy A.; Churpita, Olexandr; Lunova, M.; Jirsa, M.; Dejneka, Alexandr; Kubinová, Šárka

2017-01-01

Roč. 7, č. 1 (2017), s. 1-17, č. článku 600. ISSN 2045-2322 Grant - others:AV ČR(CZ) Fellowship J. E. Purkyně Institutional support: RVO:68378271 Keywords : chemically different * non-thermal plasmas * target distinct cell death pathways Subject RIV: BO - Biophysics OBOR OECD: Biophysics Impact factor: 4.259, year: 2016

Distinctiveness and Bidirectional Effects in Input Enhancement for Vocabulary Learning

Science.gov (United States)

Barcroft, Joe

2003-01-01

This study examined input enhancement and second language (L2) vocabulary learning while exploring the role of "distinctiveness," the degree to which an item in the input diverges from the form in which other items in the input are presented, with regard to the nature and direction of the effects of enhancement. In this study,…

Early- versus Late-Onset Dysthymia: A Meaningful Clinical Distinction?

OpenAIRE

Sansone, Randy A.; Sansone, Lori A.

2009-01-01

In the current Diagnostic and Statistical Manual of Mental Disorders, dysthymic disorder is categorized as either early-onset or late-onset, based upon the emergence of symptoms before or after the age of 21, respectively. Does this diagnostic distinction have any meaningful clinical implications? In this edition of The Interface, we present empirical studies that have, within a single study, compared individuals with early-versus late-onset dysthymia. In this review, we found that, compared ...

The loss of short-term visual representations over time: decay or temporal distinctiveness?

Science.gov (United States)

Mercer, Tom

2014-12-01

There has been much recent interest in the loss of visual short-term memories over the passage of time. According to decay theory, visual representations are gradually forgotten as time passes, reflecting a slow and steady distortion of the memory trace. However, this is controversial and decay effects can be explained in other ways. The present experiment aimed to reexamine the maintenance and loss of visual information over the short term. Decay and temporal distinctiveness models were tested using a delayed discrimination task, in which participants compared complex and novel objects over unfilled retention intervals of variable length. Experiment 1 found no significant change in the accuracy of visual memory from 2 to 6 s, but the gap separating trials reliably influenced task performance. Experiment 2 found evidence for information loss at a 10-s retention interval, but temporally separating trials restored the fidelity of visual memory, possibly because temporally isolated representations are distinct from older memory traces. In conclusion, visual representations lose accuracy at some point after 6 s, but only within temporally crowded contexts. These findings highlight the importance of temporal distinctiveness within visual short-term memory. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Distinct trajectories of positive and negative affect after colorectal cancer diagnosis

NARCIS (Netherlands)

Ciere, Yvette; Janse, Moniek; Almansa, Josué; Visser, Annemieke; Sanderman, Robbert; Sprangers, Mirjam A.G.; Ranchor, Adelita V.; Fleer, Joke

2017-01-01

Objective: Insight into trajectories of positive affect (PA) and negative affect (NA) across the cancer continuum may improve understanding of the nature of adjustment problems. The primary aim of this study was to identify subgroups of patients with distinct trajectories of PA and NA following

Distinct Trajectories of Positive and Negative Affect After Colorectal Cancer Diagnosis

NARCIS (Netherlands)

Ciere, Yvette; Janse, Moniek; Almansa, Josué; Visser, Annemieke; Sanderman, Robbert; Sprangers, Mirjam A G; Ranchor, Adelita V; Fleer, Joke

OBJECTIVE: Insight into trajectories of positive affect (PA) and negative affect (NA) across the cancer continuum may improve understanding of the nature of adjustment problems. The primary aim of this study was to identify subgroups of patients with distinct trajectories of PA and NA following

A natural M RNA reassortant arising from two distinct tospovirus species

Science.gov (United States)

The complete nucleotide sequence of a tospovirus isolate from south Florida tomatoes was determined. Phylogenetic reconstructions of each genomic RNA segment showed that this isolate was produced by reassortment of segments from two distinct tospovirus species. The S and L segments are most closel...

Medical anthropology as an antidote for ethnocentrism in Jesus research? Putting the illness–disease distinction into perspective

Directory of Open Access Journals (Sweden)

Pieter F. Craffert

2011-04-01

Full Text Available Medicine often has side-effects or unintended consequences that are more harmful than the original disease. Medical anthropology in general and the illness–disease distinction in particular has been introduced into historical Jesus research with the intent to protect it from medicocentrism and thus to offer ways of comprehending sickness and healing in the world of Jesus and his first followers without distorting these phenomena by imposing the biomedical framework onto the texts. In particular the illness–disease distinction is used for making sense of healing accounts whilst claiming to cross the cultural gap. Based on an analysis of the illness–disease distinction in medical anthropology and its use in historical Jesus research this article suggests that instead of protecting from ethnocentrism this distinction actually increases the risk of ethnocentrism and consequently distorts in many instances the healing accounts of the New Testament.

Phenotype specific analyses reveal distinct regulatory mechanism for chronically activated p53.

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Kristina Kirschner

2015-03-01

Full Text Available The downstream functions of the DNA binding tumor suppressor p53 vary depending on the cellular context, and persistent p53 activation has recently been implicated in tumor suppression and senescence. However, genome-wide information about p53-target gene regulation has been derived mostly from acute genotoxic conditions. Using ChIP-seq and expression data, we have found distinct p53 binding profiles between acutely activated (through DNA damage and chronically activated (in senescent or pro-apoptotic conditions p53. Compared to the classical 'acute' p53 binding profile, 'chronic' p53 peaks were closely associated with CpG-islands. Furthermore, the chronic CpG-island binding of p53 conferred distinct expression patterns between senescent and pro-apoptotic conditions. Using the p53 targets seen in the chronic conditions together with external high-throughput datasets, we have built p53 networks that revealed extensive self-regulatory 'p53 hubs' where p53 and many p53 targets can physically interact with each other. Integrating these results with public clinical datasets identified the cancer-associated lipogenic enzyme, SCD, which we found to be directly repressed by p53 through the CpG-island promoter, providing a mechanistic link between p53 and the 'lipogenic phenotype', a hallmark of cancer. Our data reveal distinct phenotype associations of chronic p53 targets that underlie specific gene regulatory mechanisms.

Molecular cloning and pharmacology of functionally distinct isoforms of the human histamine H(3) receptor

DEFF Research Database (Denmark)

Wellendorph, Petrine; Goodman, M W; Burstein, E S

2002-01-01

The pharmacology of histamine H(3) receptors suggests the presence of distinct receptor isoforms or subtypes. We herein describe multiple, functionally distinct, alternatively spliced isoforms of the human H(3) receptor. Combinatorial splicing at three different sites creates at least six distinct...... receptor isoforms, of which isoforms 1, 2, and 4, encode functional proteins. Detailed pharmacology on isoforms 1 (unspliced receptor), and 2 (which has an 80 amino acid deletion within the third intracellular loop of the protein) revealed that both isoforms displayed robust responses to a series of known...... revealed a rank order of potency at both isoforms of clobenpropit>iodophenpropit>thioperamide, and these drugs are fivefold less potent at isoform 2 than isoform 1. To further explore the pharmacology of H(3) receptor function, we screened 150 clinically relevant neuropsychiatric drugs for H(3) receptor...

Dealing with Distinctiveness. Development of Chinese in the "Australian Curriculum: Languages"

Science.gov (United States)

Scrimgeour, Andrew; Foster, Marnie; Mao, Weifeng

2013-01-01

This article explores some of the distinctive challenges in Chinese language education in schools and discusses how the development of the "Australian Curriculum: Chinese" has responded to these challenges. It details how the curriculum framework outlined in the "Shape of the Australian Curriculum: Languages" (ACARA, 2011)…

How Does Knowledge Promote Memory? The Distinctiveness Theory of Skilled Memory

Science.gov (United States)

Rawson, Katherine A.; Van Overschelde, James P.

2008-01-01

The robust effects of knowledge on memory for domain-relevant information reported in previous research have largely been attributed to improved organizational processing. The present research proposes the distinctiveness theory of skilled memory, which states that knowledge improves memory not only through improved organizational processing but…

The effects of cue distinctiveness on odor-based context-dependent memory.

Science.gov (United States)

Herz, R S

1997-05-01

The distinctiveness of an ambient odor was examined in relation to its success as a cue in context-dependent memory. Distinctiveness was examined in terms of both cue novelty and contextual appropriateness. Two experiments were conducted in which three different ambient odors that varied in familiarity and contextual appropriateness were manipulated at an incidental word learning encoding session and at a free recall retrieval session 48 h later. Experiment 1 revealed that when a novel ambient odor (osmanthus) was the available context cue, word recall was better than in any other condition. Further, among familiar odor cues, recall was better with a contextually inappropriate odor (peppermint) than with a contextually appropriate odor (clean fresh pine). Experiment 2 confirmed that superior word recall with osmanthus and peppermint depended on the odor cue's being available at both encoding and retrieval, and that the relation of an odor to the situational context is a key factor for predicting its effectiveness as a retrieval cue.

Pengabaian Distinction Principle dalam Situasi Blokade oleh Israel di Jalur Gaza

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Erwin Erwin

2013-12-01

Full Text Available Abstrak      Konflik bersenjata (perang telah ada dan terjadi ribuan tahun yang lalu walaupun berbeda situasi dan derajat konfliknya dengan konflik bersenjata (perang pada masa modern seperti sekarang. Salah satu konflik yang terjadi dalam sejarah modern peradaban manusia adalah konflik Israel-Palestina. Dalam catatan sejarah peradaban manusia, konflik Israel-Palestina merupakan salah satu konflik terpanjang di dunia, karena sampai saat inipun masih terjadi. Terdapat banyak upaya perdamaian dan perjanjian terus dilakukan berbagai pihak untuk merintis dan mencapai kesepakatan perdamaian, akan tetapi konflik tetap terus terjadi. Adapun peristiwa yang terjadi sebagai bagian dari konflik Israel-Palestina adalah terjadinya blokade atas Gaza pada bulan Juli tahun 2007 oleh Israel. Blokade Israel di Gaza telah mengabaikan prinsip pembedaan (distinction combatan dan civilian (penduduk sipil. Dengan alasan apapun tindakan blokade Israel telah melanggar hukum internasional pada umumnya dan Hukum Humaniter Internasional (HHI pada khususnya.Kata Kunci : Blokade, Gaza, Distinction Principle

75 FR 77602 - Endangered and Threatened Species; 90-Day Finding on Petitions To Delist the Eastern Distinct...

Science.gov (United States)

2010-12-13

... the Eastern Distinct Population Segment of the Steller Sea Lion AGENCY: National Marine Fisheries... delist the eastern Distinct Population Segment (DPS) of the Steller Sea Lion (Eumetopias jubatus) under...-implementing regulations issued by NMFS and the U.S. Fish and Wildlife Service (FWS) also establish procedures...

The interaction between awareness of one's own speech disorder with linguistics variables: distinctive features and severity of phonological disorder.

Science.gov (United States)

Dias, Roberta Freitas; Melo, Roberta Michelon; Mezzomo, Carolina Lisbôa; Mota, Helena Bolli

2013-01-01

To analyze the possible relationship among the awareness of one's own speech disorder and some aspects of the phonological system, as the number and the type of changed distinctive features, as well as the interaction among the severity of the disorder and the non-specification of distinctive features. The analyzed group has 23 children with diagnosis of speech disorder, aged 5:0 to 7:7. The speech data were analyzed through the Distinctive Features Analysis and classified by the Percentage of Correct Consonants. One also applied the Awareness of one's own speech disorder test. The children were separated in two groups: with awareness of their own speech disorder established (more than 50% of correct identification) and without awareness of their own speech disorder established (less than 50% of correct identification). Finally, the variables of this research were submitted to analysis using descriptive and inferential statistics. The type of changed distinctive features weren't different between the groups, as well as the total of changed features and the severity disorder. However, a correlation between the severity disorder and the non-specification of distinctive features was verified, because the more severe disorders have more changes in these linguistic variables. The awareness of one's own speech disorder doesn't seem to be directly influenced by the type and by the number of changed distinctive features, neither by the speech disorder severity. Moreover, one verifies that the greater phonological disorder severity, the greater the number of changed distinctive features.

Temporomandibular joint formation requires two distinct hedgehog-dependent steps.

Science.gov (United States)

Purcell, Patricia; Joo, Brian W; Hu, Jimmy K; Tran, Pamela V; Calicchio, Monica L; O'Connell, Daniel J; Maas, Richard L; Tabin, Clifford J

2009-10-27

We conducted a genetic analysis of the developing temporo-mandibular or temporomandi-bular joint (TMJ), a highly specialized synovial joint that permits movement and function of the mammalian jaw. First, we used laser capture microdissection to perform a genome-wide expression analysis of each of its developing components. The expression patterns of genes identified in this screen were examined in the TMJ and compared with those of other synovial joints, including the shoulder and the hip joints. Striking differences were noted, indicating that the TMJ forms via a distinct molecular program. Several components of the hedgehog (Hh) signaling pathway are among the genes identified in the screen, including Gli2, which is expressed specifically in the condyle and in the disk of the developing TMJ. We found that mice deficient in Gli2 display aberrant TMJ development such that the condyle loses its growth-plate-like cellular organization and no disk is formed. In addition, we used a conditional strategy to remove Smo, a positive effector of the Hh signaling pathway, from chondrocyte progenitors. This cell autonomous loss of Hh signaling allows for disk formation, but the resulting structure fails to separate from the condyle. Thus, these experiments establish that Hh signaling acts at two distinct steps in disk morphogenesis, condyle initiation, and disk-condyle separation and provide a molecular framework for future studies of the TMJ.

Distinct pathways of neural coupling for different basic emotions.

Science.gov (United States)

Tettamanti, Marco; Rognoni, Elena; Cafiero, Riccardo; Costa, Tommaso; Galati, Dario; Perani, Daniela

2012-01-16

Emotions are complex events recruiting distributed cortical and subcortical cerebral structures, where the functional integration dynamics within the involved neural circuits in relation to the nature of the different emotions are still unknown. Using fMRI, we measured the neural responses elicited by films representing basic emotions (fear, disgust, sadness, happiness). The amygdala and the associative cortex were conjointly activated by all basic emotions. Furthermore, distinct arrays of cortical and subcortical brain regions were additionally activated by each emotion, with the exception of sadness. Such findings informed the definition of three effective connectivity models, testing for the functional integration of visual cortex and amygdala, as regions processing all emotions, with domain-specific regions, namely: i) for fear, the frontoparietal system involved in preparing adaptive motor responses; ii) for disgust, the somatosensory system, reflecting protective responses against contaminating stimuli; iii) for happiness: medial prefrontal and temporoparietal cortices involved in understanding joyful interactions. Consistently with these domain-specific models, the results of the effective connectivity analysis indicate that the amygdala is involved in distinct functional integration effects with cortical networks processing sensorimotor, somatosensory, or cognitive aspects of basic emotions. The resulting effective connectivity networks may serve to regulate motor and cognitive behavior based on the quality of the induced emotional experience. Copyright © 2011. Published by Elsevier Inc.

Distinct functional programming of human fetal and adult monocytes.

Science.gov (United States)

Krow-Lucal, Elisabeth R; Kim, Charles C; Burt, Trevor D; McCune, Joseph M

2014-03-20

Preterm birth affects 1 out of 9 infants in the United States and is the leading cause of long-term neurologic handicap and infant mortality, accounting for 35% of all infant deaths in 2008. Although cytokines including interferon-γ (IFN-γ), interleukin-10 (IL-10), IL-6, and IL-1 are produced in response to in utero infection and are strongly associated with preterm labor, little is known about how human fetal immune cells respond to these cytokines. We demonstrate that fetal and adult CD14(+)CD16(-) classical monocytes are distinct in terms of basal transcriptional profiles and in phosphorylation of signal transducers and activators of transcription (STATs) in response to cytokines. Fetal monocytes phosphorylate canonical and noncanonical STATs and respond more strongly to IFN-γ, IL-6, and IL-4 than adult monocytes. We demonstrate a higher ratio of SOCS3 to IL-6 receptor in adult monocytes than in fetal monocytes, potentially explaining differences in STAT phosphorylation. Additionally, IFN-γ signaling results in upregulation of antigen presentation and costimulatory machinery in adult, but not fetal, monocytes. These findings represent the first evidence that primary human fetal and adult monocytes are functionally distinct, potentially explaining how these cells respond differentially to cytokines implicated in development, in utero infections, and the pathogenesis of preterm labor.

Distinct trajectories of positive and negative affect after colorectal cancer diagnosis.

Science.gov (United States)

Ciere, Yvette; Janse, Moniek; Almansa, Josué; Visser, Annemieke; Sanderman, Robbert; Sprangers, Mirjam A G; Ranchor, Adelita V; Fleer, Joke

2017-06-01

Insight into trajectories of positive affect (PA) and negative affect (NA) across the cancer continuum may improve understanding of the nature of adjustment problems. The primary aim of this study was to identify subgroups of patients with distinct trajectories of PA and NA following diagnosis of colorectal cancer (CRC). Secondary to this aim, the co-occurrence between trajectories and their association with goal-related processes was explored. CRC patients (n = 186) completed questionnaires within 1 month, 7 months, and 18 months after diagnosis. Multilevel models were used to study the trajectory of PA and NA, as measured with the Positive and Negative Affect Schedule (PANAS). Four classes with distinct PA trajectories were identified: low (18.8%), increasing (6.7%), moderate (68.2%), and high (6.3%); 2 trajectories of NA emerged: low (36.3%) and moderate (63.7%). There was no significant association between PA and NA trajectory class probabilities. The average trajectory of PA covaried with levels of goal disturbance and goal reengagement over time, while the average NA trajectory covaried with goal disturbance and goal disengagement. Compared with the general population, our sample of cancer patients suffered from a lack of positive emotions, but not a high presence of negative emotions. About one fifth of patients reported low PA up to 18 months after diagnosis and may benefit from supportive care. Furthermore, the trajectory of PA was independent of that of NA and related with a distinct goal adjustment process (i.e., goal disengagement vs. goal reengagement). This finding indicates the need to tailor psychological care to the nature of the adjustment problem. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Selfish genetic elements favor the evolution of a distinction between soma and germline.

Science.gov (United States)

Johnson, Louise J

2008-08-01

Many multicellular organisms have evolved a dedicated germline. This can benefit the whole organism, but its advantages to genetic parasites have not been explored. Here I model the evolutionary success of a selfish element, such as a transposable element or endosymbiont, which is capable of creating or strengthening a germline-soma distinction in a primitively multicellular host, and find that it will always benefit the element to do so. Genes causing germline sequestration can therefore spread in a population even if germline sequestration is maladaptive for the host organism. Costly selfish elements are expected to survive only in sexual populations, so sexual species may experience an additional push toward germline-soma distinction, and hence toward cell differentiation and multicellularity.

Preserved Self-Other Distinction during Empathy in Autism Is Linked to Network Integrity of Right Supramarginal Gyrus

Science.gov (United States)

Hoffmann, Ferdinand; Koehne, Svenja; Steinbeis, Nikolaus; Dziobek, Isabel; Singer, Tania

2016-01-01

Autism spectrum disorder (ASD) shows deficits in self-other distinction during theory of mind (ToM). Here we investigated whether ASD patients also show difficulties in self-other distinction during empathy and if potential deficits are linked to dysfunctional resting-state connectivity patterns. In a first study, ASD patients and controls…

Learning-performance distinction and memory processes for motor skills: a focused review and perspective.

Science.gov (United States)

Kantak, Shailesh S; Winstein, Carolee J

2012-03-01

Behavioral research in cognitive psychology provides evidence for an important distinction between immediate performance that accompanies practice and long-term performance that reflects the relative permanence in the capability for the practiced skill (i.e. learning). This learning-performance distinction is strikingly evident when challenging practice conditions may impair practice performance, but enhance long-term retention of motor skills. A review of motor learning studies with a specific focus on comparing differences in performance between that at the end of practice and at delayed retention suggests that the delayed retention or transfer performance is a better indicator of motor learning than the performance at (or end of) practice. This provides objective evidence for the learning-performance distinction. This behavioral evidence coupled with an understanding of the motor memory processes of encoding, consolidation and retrieval may provide insight into the putative mechanism that implements the learning-performance distinction. Here, we propose a simplistic empirically-based framework--motor behavior-memory framework--that integrates the temporal evolution of motor memory processes with the time course of practice and delayed retention frequently used in behavioral motor learning paradigms. In the context of the proposed framework, recent research has used noninvasive brain stimulation to decipher the role of each motor memory process, and specific cortical brain regions engaged in motor performance and learning. Such findings provide beginning insights into the relationship between the time course of practice-induced performance changes and motor memory processes. This in turn has promising implications for future research and practical applications. Copyright © 2011 Elsevier B.V. All rights reserved.

Core Competence, Distinctive Competence, and Competitive Advantage: What Is the Difference?

Science.gov (United States)

Mooney, Ann

2007-01-01

Core competence, distinctive competence, and competitive advantage are 3 of the most important business concepts that managers, researchers, and educators rely on for decision making, pedagogy, and research. However, little attention has been paid to defining these concepts. As a result, they have become buzzwords that are used so frequently that…

Distinct mutational signatures characterize concurrent loss of polymerase proofreading and mismatch repair.

Science.gov (United States)

Haradhvala, N J; Kim, J; Maruvka, Y E; Polak, P; Rosebrock, D; Livitz, D; Hess, J M; Leshchiner, I; Kamburov, A; Mouw, K W; Lawrence, M S; Getz, G

2018-05-01

Fidelity of DNA replication is maintained using polymerase proofreading and the mismatch repair pathway. Tumors with loss of function of either mechanism have elevated mutation rates with characteristic mutational signatures. Here we report that tumors with concurrent loss of both polymerase proofreading and mismatch repair function have mutational patterns that are not a simple sum of the signatures of the individual alterations, but correspond to distinct, previously unexplained signatures: COSMIC database signatures 14 and 20. We then demonstrate that in all five cases in which the chronological order of events could be determined, polymerase epsilon proofreading alterations precede the defect in mismatch repair. Overall, we illustrate that multiple distinct mutational signatures can result from different combinations of a smaller number of mutational processes (of either damage or repair), which can influence the interpretation and discovery of mutational signatures.

Concurrent topological design of composite structures and materials containing multiple phases of distinct Poisson's ratios

Science.gov (United States)

Long, Kai; Yuan, Philip F.; Xu, Shanqing; Xie, Yi Min

2018-04-01

Most studies on composites assume that the constituent phases have different values of stiffness. Little attention has been paid to the effect of constituent phases having distinct Poisson's ratios. This research focuses on a concurrent optimization method for simultaneously designing composite structures and materials with distinct Poisson's ratios. The proposed method aims to minimize the mean compliance of the macrostructure with a given mass of base materials. In contrast to the traditional interpolation of the stiffness matrix through numerical results, an interpolation scheme of the Young's modulus and Poisson's ratio using different parameters is adopted. The numerical results demonstrate that the Poisson effect plays a key role in reducing the mean compliance of the final design. An important contribution of the present study is that the proposed concurrent optimization method can automatically distribute base materials with distinct Poisson's ratios between the macrostructural and microstructural levels under a single constraint of the total mass.

Seismic isolation systems designed with distinct multiple frequencies

International Nuclear Information System (INIS)

Wu, Ting-shu; Seidensticker, R.W.

1991-01-01

Two systems for seismic base isolation are presented. The main feature of these system is that, instead of only one isolation frequency as in conventional isolation systems, they are designed to have two distinct isolation frequencies. When the responses during an earthquake exceed the design value(s), the system will automatically and passively shift to the secondly isolation frequency. Responses of these two systems to different ground motions including a harmonic motion with frequency same as the primary isolation frequency, show that no excessive amplification will occur. Adoption of these new systems certainly will greatly enhance the safety and reliability of an isolated superstructure against future strong earthquakes. 3 refs

Distinct termination morphologies for vertically aligned carbon nanotube forests

International Nuclear Information System (INIS)

Vinten, P; Marshall, P; Lefebvre, J; Finnie, P

2010-01-01

Vertically aligned carbon nanotube forests, including single-walled nanotubes, are imaged optically as they grow in situ from cobalt/alumina catalyst using water-assisted acetylene chemical vapor deposition. Three distinct termination morphologies are identified and investigated optically and via scanning electron microscopy. Quantitative growth dynamics are extracted and show gradual deceleration and sudden termination of growth. The termination morphology is discussed in terms of the balance of forces within the forest. We speculate that sudden termination is a collective effect arising from an imbalance in these forces.

Analysis of the electrochemical reactivity of natural hemozoin and β-hemozoin in the presence of antimalarial drugs

International Nuclear Information System (INIS)

Esteban Reyes-Cruz, Victor; Urbano Reyes, Gustavo; Veloz Rodriguez, Maria Aurora; Imbert Palafox, Jose Luis

2011-01-01

We report an evaluation of the reactivity of hemozoin (HZ) and β-hemozoin (β-HZ) obtained from the Triatoma Meccus longipennis, alone and in combination with quinine and amodiaquine. Using cyclic voltammetry and carbon paste electrodes, the redox processes that these compounds undergo were analysed. The results indicated that the atom Fe presence, the substance concentration, the drugs existence and the nature of the electrolytic medium are important in the redox processes. The strongest reactivity was for β-HZ from Triatoma, which suggests that cellular molecules are embedded in an oxidising environment due to the presence of β-HZ and indicates that like HZ, β-HZ could be associate with phospholipid bilayers and interfere with their physical and chemical integrity, contributing to membrane breakdown and hyper-oxidation of molecules. It was further observed that when measuring the reactivity of HZ and β-HZ with quinine and amodiaquine, a more oxidative stress was generated between the second one and the β-HZ, which could explain the effectiveness of amodiaquine as a better antimalarial drug. Finally, it was concluded that electrochemical evaluation may be a convenient tool in determining the efficiency of antimalarial drugs and the identification of their redox processes.

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

Directory of Open Access Journals (Sweden)

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.

Analysis of the electrochemical reactivity of natural hemozoin and {beta}-hemozoin in the presence of antimalarial drugs

Energy Technology Data Exchange (ETDEWEB)

Esteban Reyes-Cruz, Victor, E-mail: reyescruz16@yahoo.com [Area Academica de Ciencias de la Tierra y Materiales, Instituto de Ciencias Basicas e Ingenieria, Universidad Autonoma del Estado de Hidalgo (Mexico); Urbano Reyes, Gustavo, E-mail: gurbano2003@yahoo.com.mx [Area Academica de Ciencias de la Tierra y Materiales, Instituto de Ciencias Basicas e Ingenieria, Universidad Autonoma del Estado de Hidalgo (Mexico); Veloz Rodriguez, Maria Aurora, E-mail: maveloz70@yahoo.com.mx [Area Academica de Ciencias de la Tierra y Materiales, Instituto de Ciencias Basicas e Ingenieria, Universidad Autonoma del Estado de Hidalgo (Mexico); Imbert Palafox, Jose Luis, E-mail: imbertox@hotmail.com [Area Academica de Medicina, Instituto de Ciencias de la Salud, Universidad Autonoma del Estado de Hidalgo (Mexico)

2011-11-30

We report an evaluation of the reactivity of hemozoin (HZ) and {beta}-hemozoin ({beta}-HZ) obtained from the Triatoma Meccus longipennis, alone and in combination with quinine and amodiaquine. Using cyclic voltammetry and carbon paste electrodes, the redox processes that these compounds undergo were analysed. The results indicated that the atom Fe presence, the substance concentration, the drugs existence and the nature of the electrolytic medium are important in the redox processes. The strongest reactivity was for {beta}-HZ from Triatoma, which suggests that cellular molecules are embedded in an oxidising environment due to the presence of {beta}-HZ and indicates that like HZ, {beta}-HZ could be associate with phospholipid bilayers and interfere with their physical and chemical integrity, contributing to membrane breakdown and hyper-oxidation of molecules. It was further observed that when measuring the reactivity of HZ and {beta}-HZ with quinine and amodiaquine, a more oxidative stress was generated between the second one and the {beta}-HZ, which could explain the effectiveness of amodiaquine as a better antimalarial drug. Finally, it was concluded that electrochemical evaluation may be a convenient tool in determining the efficiency of antimalarial drugs and the identification of their redox processes.

Distinctive Correspondence Between Separable Visual Attention Functions and Intrinsic Brain Networks.

Science.gov (United States)

Ruiz-Rizzo, Adriana L; Neitzel, Julia; Müller, Hermann J; Sorg, Christian; Finke, Kathrin

2018-01-01

Separable visual attention functions are assumed to rely on distinct but interacting neural mechanisms. Bundesen's "theory of visual attention" (TVA) allows the mathematical estimation of independent parameters that characterize individuals' visual attentional capacity (i.e., visual processing speed and visual short-term memory storage capacity) and selectivity functions (i.e., top-down control and spatial laterality). However, it is unclear whether these parameters distinctively map onto different brain networks obtained from intrinsic functional connectivity, which organizes slowly fluctuating ongoing brain activity. In our study, 31 demographically homogeneous healthy young participants performed whole- and partial-report tasks and underwent resting-state functional magnetic resonance imaging (rs-fMRI). Report accuracy was modeled using TVA to estimate, individually, the four TVA parameters. Networks encompassing cortical areas relevant for visual attention were derived from independent component analysis of rs-fMRI data: visual, executive control, right and left frontoparietal, and ventral and dorsal attention networks. Two TVA parameters were mapped on particular functional networks. First, participants with higher (vs. lower) visual processing speed showed lower functional connectivity within the ventral attention network. Second, participants with more (vs. less) efficient top-down control showed higher functional connectivity within the dorsal attention network and lower functional connectivity within the visual network. Additionally, higher performance was associated with higher functional connectivity between networks: specifically, between the ventral attention and right frontoparietal networks for visual processing speed, and between the visual and executive control networks for top-down control. The higher inter-network functional connectivity was related to lower intra-network connectivity. These results demonstrate that separable visual attention

Cognitive, cultural, and linguistic sources of a handshape distinction expressing agentivity.

Science.gov (United States)

Brentari, Diane; Di Renzo, Alessio; Keane, Jonathan; Volterra, Virginia

2015-01-01

In this paper the cognitive, cultural, and linguistic bases for a pattern of conventionalization of two types of iconic handshapes are described. Work on sign languages has shown that handling handshapes (H-HSs: those that represent how objects are handled or manipulated) and object handshapes (O-HSs: those that represent the class, size, or shape of objects) express an agentive/non-agentive semantic distinction in many sign languages. H-HSs are used in agentive event descriptions and O-HSs are used in non-agentive event descriptions. In this work, American Sign Language (ASL) and Italian Sign Language (LIS) productions are compared (adults and children) as well as the corresponding groups of gesturers in each country using "silent gesture." While the gesture groups, in general, did not employ an H-HS/O-HS distinction, all participants (signers and gesturers) used iconic handshapes (H-HSs and O-HSs together) more often in agentive than in no-agent event descriptions; moreover, none of the subjects produced an opposite pattern than the expected one (i.e., H-HSs associated with no-agent descriptions and O-HSs associated with agentive ones). These effects are argued to be grounded in cognition. In addition, some individual gesturers were observed to produce the H-HS/O-HS opposition for agentive and non-agentive event descriptions-that is, more Italian than American adult gesturers. This effect is argued to be grounded in culture. Finally, the agentive/non-agentive handshape opposition is confirmed for signers of ASL and LIS, but previously unreported cross-linguistic differences were also found across both adult and child sign groups. It is, therefore, concluded that cognitive, cultural, and linguistic factors contribute to the conventionalization of this distinction of handshape type. Copyright © 2014 Cognitive Science Society, Inc.

Distinctive Correspondence Between Separable Visual Attention Functions and Intrinsic Brain Networks

Science.gov (United States)

Ruiz-Rizzo, Adriana L.; Neitzel, Julia; Müller, Hermann J.; Sorg, Christian; Finke, Kathrin

2018-01-01

Separable visual attention functions are assumed to rely on distinct but interacting neural mechanisms. Bundesen's “theory of visual attention” (TVA) allows the mathematical estimation of independent parameters that characterize individuals' visual attentional capacity (i.e., visual processing speed and visual short-term memory storage capacity) and selectivity functions (i.e., top-down control and spatial laterality). However, it is unclear whether these parameters distinctively map onto different brain networks obtained from intrinsic functional connectivity, which organizes slowly fluctuating ongoing brain activity. In our study, 31 demographically homogeneous healthy young participants performed whole- and partial-report tasks and underwent resting-state functional magnetic resonance imaging (rs-fMRI). Report accuracy was modeled using TVA to estimate, individually, the four TVA parameters. Networks encompassing cortical areas relevant for visual attention were derived from independent component analysis of rs-fMRI data: visual, executive control, right and left frontoparietal, and ventral and dorsal attention networks. Two TVA parameters were mapped on particular functional networks. First, participants with higher (vs. lower) visual processing speed showed lower functional connectivity within the ventral attention network. Second, participants with more (vs. less) efficient top-down control showed higher functional connectivity within the dorsal attention network and lower functional connectivity within the visual network. Additionally, higher performance was associated with higher functional connectivity between networks: specifically, between the ventral attention and right frontoparietal networks for visual processing speed, and between the visual and executive control networks for top-down control. The higher inter-network functional connectivity was related to lower intra-network connectivity. These results demonstrate that separable visual attention

Distinctive Correspondence Between Separable Visual Attention Functions and Intrinsic Brain Networks

Directory of Open Access Journals (Sweden)

Adriana L. Ruiz-Rizzo

2018-03-01

Full Text Available Separable visual attention functions are assumed to rely on distinct but interacting neural mechanisms. Bundesen's “theory of visual attention” (TVA allows the mathematical estimation of independent parameters that characterize individuals' visual attentional capacity (i.e., visual processing speed and visual short-term memory storage capacity and selectivity functions (i.e., top-down control and spatial laterality. However, it is unclear whether these parameters distinctively map onto different brain networks obtained from intrinsic functional connectivity, which organizes slowly fluctuating ongoing brain activity. In our study, 31 demographically homogeneous healthy young participants performed whole- and partial-report tasks and underwent resting-state functional magnetic resonance imaging (rs-fMRI. Report accuracy was modeled using TVA to estimate, individually, the four TVA parameters. Networks encompassing cortical areas relevant for visual attention were derived from independent component analysis of rs-fMRI data: visual, executive control, right and left frontoparietal, and ventral and dorsal attention networks. Two TVA parameters were mapped on particular functional networks. First, participants with higher (vs. lower visual processing speed showed lower functional connectivity within the ventral attention network. Second, participants with more (vs. less efficient top-down control showed higher functional connectivity within the dorsal attention network and lower functional connectivity within the visual network. Additionally, higher performance was associated with higher functional connectivity between networks: specifically, between the ventral attention and right frontoparietal networks for visual processing speed, and between the visual and executive control networks for top-down control. The higher inter-network functional connectivity was related to lower intra-network connectivity. These results demonstrate that separable

Improvement of the Owner Distinction Method for Healing-Type Pet Robots

Science.gov (United States)

Nambo, Hidetaka; Kimura, Haruhiko; Hara, Mirai; Abe, Koji; Tajima, Takuya

In order to decrease human stress, Animal Assisted Therapy which applies pets to heal humans is attracted. However, since animals are insanitary and unsafe, it is difficult to practically apply animal pets in hospitals. For the reason, on behalf of animal pets, pet robots have been attracted. Since pet robots would have no problems in sanitation and safety, they are able to be applied as a substitute for animal pets in the therapy. In our previous study where pet robots distinguish their owners like an animal pet, we used a puppet type pet robot which has pressure type touch sensors. However, the accuracy of our method was not sufficient to practical use. In this paper, we propose a method to improve the accuracy of the distinction. The proposed method can be applied for capacitive touch sensors such as installed in AIBO in addition to pressure type touch sensors. Besides, this paper shows performance of the proposed method from experimental results and confirms the proposed method has improved performance of the distinction in the conventional method.

Overexpressed Genes/ESTs and Characterization of Distinct Amplicons on 17823 in Breast Cancer Cells

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Ayse E. Erson

2001-01-01

Full Text Available 17823 is a frequent site of gene amplification in breast cancer. Several lines of evidence suggest the presence of multiple amplicons on 17823. To characterize distinct amplicons on 17823 and localize putative oncogenes, we screened genes and expressed sequence tags (ESTs in existing physical and radiation hybrid maps for amplification and overexpression in breast cancer cell lines by semiquantitative duplex PCR, semiquantitative duplex RT-PCR, Southern blot, Northern blot analyses. We identified two distinct amplicons on 17823, one including TBX2 and another proximal region including RPS6KB1 (PS6K and MUL. In addition to these previously reported overexpressed genes, we also identified amplification and overexpression of additional uncharacterized genes and ESTs, some of which suggest potential oncogenic activity. In conclusion, we have further defined two distinct regions of gene amplification and overexpression on 17823 with identification of new potential oncogene candidates. Based on the amplification and overexpression patterns of known and as of yet unrecognized genes on 17823, it is likely that some of these genes mapping to the discrete amplicons function as oncogenes and contribute to tumor progression in breast cancer cells.

Differential regulation of microtubule severing by APC underlies distinct patterns of projection neuron and interneuron migration

Science.gov (United States)

Eom, Tae-Yeon; Stanco, Amelia; Guo, Jiami; Wilkins, Gary; Deslauriers, Danielle; Yan, Jessica; Monckton, Chase; Blair, Josh; Oon, Eesim; Perez, Abby; Salas, Eduardo; Oh, Adrianna; Ghukasyan, Vladimir; Snider, William D.; Rubenstein, John L. R.; Anton, E. S.

2014-01-01

Coordinated migration of distinct classes of neurons to appropriate positions leads to the formation of functional neuronal circuitry in the cerebral cortex. Two major classes of cortical neurons, interneurons and projection neurons, utilize distinctly different modes (radial vs. tangential) and routes of migration to arrive at their final positions in the cerebral cortex. Here, we show that adenomatous polyposis coli (APC) modulates microtubule (MT) severing in interneurons to facilitate tangential mode of interneuron migration, but not the glial-guided, radial migration of projection neurons. APC regulates the stability and activity of the MT severing protein p60-katanin in interneurons to promote the rapid remodeling of neuronal processes necessary for interneuron migration. These findings reveal how severing and restructuring of MTs facilitate distinct modes of neuronal migration necessary for laminar organization of neurons in the developing cerebral cortex. PMID:25535916

Overlap and distinction between measures of insight and self-stigma.

Science.gov (United States)

Hasson-Ohayon, Ilanit

2018-05-24

Multiple studies on insight into one's illness and self-stigma among patients with serious mental illness and their relatives have shown that these constructs are related to one another and that they affect outcome. However, a critical exploration of the items used to assess both constructs raises questions with regard to the possible overlapping and centrality of items. The current study used five different samples to explore the possible overlap and distinction between insight and self-stigma, and to identify central items, via network analyses and principal component factor analysis. Findings from the network analyses showed overlap between insight and self-stigma exist with a relatively clearer observational distinction between the constructs among the two parent samples in comparison to the patient samples. Principal component factor analysis constrained to two factors showed that a relatively high percentage of items were not loaded on either factor, and in a few datasets, several insight items were loaded on the self-stigma scale and vice versa. The author discusses implications for research and calls for rethinking the way insight is assessed. Clinical implications are also discussed in reference to central items of social isolation, future worries and stereotype endorsement among the different study groups. Copyright © 2018 Elsevier B.V. All rights reserved.

Comorbid obsessive-compulsive disorder with bipolar disorder: A distinct form?

Science.gov (United States)

Ozdemiroglu, Filiz; Sevincok, Levent; Sen, Gulnur; Mersin, Sanem; Kocabas, Oktay; Karakus, Kadir; Vahapoglu, Fatih

2015-12-30

We examined whether the patients with Bipolar Disorder (BD) and Obsessive-Compulsive Disorder (OCD) comorbidity may represent a distinct form of BD. The subjects diagnosed with BD (n=48), OCD (n=61), and BD with OCD (n=32) were compared in terms of several socio-demographic and clinical characteristics. Previous history of suicidal attempts was more likely to be higher in BD-OCD group compared to the other two groups. A more episodic course of OCD, higher rates of rapid cycling, and the seasonality were found in BD-OCD patients. The frequency of bipolar II and NOS subtypes was more prevalent in patients with BD-OCD than in OCD patients. The first diagnosed illness was BD in the majority of BD-OCD cases. It was found that first affective episode was major depression in half of BD-OCD patients. Age at onset of BD was found to be earlier in BD-OCD group compared to pure BD patients. Bipolarity may not have a specific effect on the phenomenology of OC symptoms. The episodic course of OCD, seasonality, rapid cycling, earlier onset of BD, and impulsivity in BD-OCD patients may be indicative for a distinct form of BD. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Vertically distinct microbial communities in the Mariana and Kermadec trenches

Science.gov (United States)

Donaldson, Sierra; Osuntokun, Oladayo; Xia, Qing; Nelson, Alex; Blanton, Jessica; Allen, Eric E.; Church, Matthew J.; Bartlett, Douglas H.

2018-01-01

Hadal trenches, oceanic locations deeper than 6,000 m, are thought to have distinct microbial communities compared to those at shallower depths due to high hydrostatic pressures, topographical funneling of organic matter, and biogeographical isolation. Here we evaluate the hypothesis that hadal trenches contain unique microbial biodiversity through analyses of the communities present in the bottom waters of the Kermadec and Mariana trenches. Estimates of microbial protein production indicate active populations under in situ hydrostatic pressures and increasing adaptation to pressure with depth. Depth, trench of collection, and size fraction are important drivers of microbial community structure. Many putative hadal bathytypes, such as members related to the Marinimicrobia, Rhodobacteraceae, Rhodospirilliceae, and Aquibacter, are similar to members identified in other trenches. Most of the differences between the two trench microbiomes consists of taxa belonging to the Gammaproteobacteria whose distributions extend throughout the water column. Growth and survival estimates of representative isolates of these taxa under deep-sea conditions suggest that some members may descend from shallower depths and exist as a potentially inactive fraction of the hadal zone. We conclude that the distinct pelagic communities residing in these two trenches, and perhaps by extension other trenches, reflect both cosmopolitan hadal bathytypes and ubiquitous genera found throughout the water column. PMID:29621268

Examining the Distinctiveness and the Socio-Emotional Correlates of Anxious-Withdrawal and Unsociability during Early Adolescence in Finland

Science.gov (United States)

Ojanen, Tiina; Findley-Van Nostrand, Danielle; Bowker, Julie C.; Markovic, Andrea

2017-01-01

This study examined the distinctiveness of and the correlates associated with anxious-withdrawal and unsociability during early adolescence in Finland (N = 384; 12-14 years; 53% girls). As expected, confirmatory factor analyses revealed that anxious-withdrawal and unsociability were distinct and moderately positively correlated constructs. Only…