615 research outputs found

    Inventario de los Calyptratae (Insecta: Diptera) saprófagos en los espacios verdes urbanos de la ciudad de Buenos Aires

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    El inventario de la biodiversidad es una tarea urgente para la conservación de los insectos. En particular, los espacios verdes urbanos (áreas sin edificaciones) dentro de entornos urbanos son un elemento fundamental para el mantenimiento y restauración de la biodiversidad. Se describe la biodiversidad de los Calyptratae saprófagos en tres espacios verdes urbanos: un jardín privado, un parque urbano, y una reserva natural en la Ciudad de Buenos Aires, Argentina, y se compara la presencia de especies cosmopolitas y nativas. Un total de 14.688 especímenes fueron colectados, representando 62 especies. Las moscas fueron capturadas con red de mano sobres cebos de atracción, vísceras de pollo en descomposición y heces caninas. Las tres especies más abundantes, Cochliomyia macellaria, Tricharaea (Sarcophagula) occidua, y Chrysomya albiceps, representan el 81,70 % de la muestra total. Las especies nativas representan 62,24 % de la muestra total y muestran un incremento en términos de riqueza en espacios más grandes y menos modificados. Se identificaron las especies cosmopolitas tratadas con “homogenizadores globales”.The biodiversity inventory is an urgent task for insect conservation. Particularly, the urban green spaces (non-built-up areas) within urban environments are a fundamental element to the maintenance and restoration of biodiversity. We describe the diversity of saprophagous Calyptratae in three urban green spaces: a private garden, an urban park, and a natural reserve in Buenos Aires City, Argentina, and we compare the presence of native and cosmopolitan species. A total of 14,688 specimens were collected, representing 62 species. The flies were captured by netting them on attractive baits, rotten viscerae of chicken and dog faeces. The three most abundant species, Cochliomyia macellaria, Tricharaea (Sarcophagula) occidua, and Chrysomya albiceps, represent 81.70 % of the total sample. Native species represented a 67.24 % of the total sample and presented an increase in terms of richness in larger and less modified spaces. Cosmopolitan species treated as "global homogenizers" were identified.Fil: Patitucci, Luciano Damián. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; ArgentinaFil: Mulieri, Pablo Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; ArgentinaFil: Dominguez, Martha Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; ArgentinaFil: Mariluis, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; Argentin

    Ensambles de múscidos saprófagos (Diptera: Muscidae) en tres sitios urbanos en la Argentina templada

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    Muscidae occupy a great diversity of habitats and trophic niches. In temperate environments, the knowledge of ecological aspects of saprophagous muscids is fragmentary. The aim of this work was to characterize the assemblages of saprophagous muscids regarding their richness and abundance, bait preference, heliophily, and seasonality of species in three sites with different urbanization levels sampled during two years in an area of temperate Argentina. A total of 3,321 specimens belonging to 20 species were collected. The baits and microhabitat preferences, and seasonal fluctuation of species were described. An increase in diversity in terms of evenness and richness in less urbanized sites was observed. Results support the hypotheses about sites with an intermediate urbanization, which contain major landscape heterogeneity, show a higher number of species. The assemblage response regarding the environment types reflects the adaptability to the physical changes along the three sites with different degree of urbanization.Las especies de Muscidae ocupan una gran diversidad de hábitats y nichos tróficos. En ambientes templados, el conocimiento de los aspectos ecológicos de múscidos saprófagos es fragmentario. El objetivo de este trabajo fue caracterizar los ensambles de múscidos saprófagos en cuanto a su riqueza y abundancia, la preferencia de cebo, heliofilia, y la estacionalidad de las especies en tres sitios con diferente nivel de urbanización colectados durante dos años en una zona templada de la Argentina. Se colectaron un total de 3.321 ejemplares pertenecientes a 20 especies. Se describen las preferencias de cebo y de microhábitat, y fluctuación estacional de las especies. Se observó un aumento de la diversidad en términos de uniformidad y riqueza en los sitios menos urbanizados. Los resultados apoyan las hipótesis sobre los sitios con una urbanización intermedia, que contienen gran heterogeneidad del paisaje, muestran un mayor número de especies. La respuesta del conjunto con respecto a los tipos de medio ambiente, refleja la capacidad de adaptación a los cambios físicos a lo largo de los tres sitios con diferente grado de urbanización.Fil: Patitucci, Luciano Damián. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales; ArgentinaFil: Mulieri, Pablo Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales; ArgentinaFil: Schnack, Juan Alberto. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mariluis, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales; Argentin

    The origins of individual differences in how learning is expressed in rats: a general-process perspective

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    Laboratory rats can exhibit marked, qualitative individual differences in the form of acquired behaviors. For example, when exposed to a signal-reinforcer relationship some rats show marked and consistent changes in sign-tracking (interacting with the signal; e.g., a lever) and others show marked and consistent changes in goal-tracking (interacting with the location of the predicted reinforcer; e.g., the food well). Here, stable individual differences in rats' sign-tracking and goal-tracking emerged over the course of training, but these differences did not generalize across different signal-reinforcer relationships (Experiment 1). This selectivity suggests that individual differences in sign- and goal-tracking reflect differences in the value placed on individual reinforcers. Two findings provide direct support for this interpretation: the palatability of a reinforcer (as measured by an analysis of lick-cluster size) was positively correlated with goal-tracking (and negatively correlated with sign-tracking); and sating rats with a reinforcer affected goal-tracking but not sign-tracking (Experiment 2). These results indicate that the observed individual differences in sign- and goal-tracking behavior arise from the interaction between the palatability or value of the reinforcer and processes of association as opposed to dispositional differences (e.g., in sensory processes, 'temperament,' or response repertoire)

    Evidencia serológica de infección por Neospora caninum en rebaños lecheros del Sur de Chile

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    Neospora caninum is a recently recognised parasite that produces infection in dogs and herbivorous. In cows, the disease does not produce clinical signs of illness, instead it produces losses. Chile has a large dairy industry and pregnancy losses in that system seem to be economically important. However a large number of abortions remain with unknown aetiology and abortion due to protozoa has not been investigated. We report here, for the first time, that aborted cows belonging to three different farms in the IX Region, Chile had antibodies to N. Caninumis given here. The episode of abortion was "sporadic" and occurred in adult cows. The sera were diluted in 1:200 and processed with the Neospora IFA test. Whole tachyzoite surface fluorescent was considered positive. Aantibodies were found in 10 of 21 adult cows, none of 2 heifers and 1 of 6 calves in farm A. In farm B, they were found in 7 of 24 adult cows and in 2 of 2 adult cows of farm C. All the aborted cows (2 on farm A; 3 aborted and 1 mummified on farm B; and 2 on farm C) were positive to the test. Taking into consideration the IFA test results and the negativity of serology to other common infections which cause bovine abortion, the hypothesis that these cows aborted due to Neospora infection is supported. How the disease has spread world wide is unknown, but most probably, international animal trade has contributed to help spread the disease. Before any recommendation can be made more extensive studies should be done in order to establish the prevalence and the economic impact of the disease. At the moment evidence that Neospora infection is already present in this country is presented. Therefore it should be included as a differential diagnosis of bovine abortion.Los abortos bovinos causan importantes pérdidas económicas a la ganadería mundial. Una parte importante de ellos permanecen aún con etiología desconocida, y de los diagnosticados, la mayoría corresponden a causas infecciosas. Dentro de ellos los abortos ocasionados por protozoos han tomado relevancia mundial. En Chile hasta ahora se desconocía su presencia. En este trabajo se presenta evidencia que vacas con antecedentes de abortos presentaron anticuerpos contra N. caninum detectados mediante la técnica IFA y se discute la posibilidad de que hayan ocurrido como consecuencia de la infección por este protozo

    Detección de anticuerpos séricos contra Toxoplasma gondii (Nicolle y Manceaux, 1909) en llamas (Lama glama Linneaus, 1758) y alpacas (Lama pacos Linneaus, 1758 ) de Chile.

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    Sera samples from 113 Ilamas (Lama glama) and 127 alpacas (Lama pacos) from the IX and V Regions, respectively, of Chile were tested for Toxoplasma gondii antibodies. The modified agglutination test (MAT) was used in both species and titers 1:25 were considered diagnostically significant based in previously published data. Sera from 49 lamas (43.3%) and 15 alpacas (11.8%) were positive to T. gondii. Percentaje seropositivity in serum dilutions of 1:25, 1:50, 1:500 and 1:5000 was 17.6%; 7.9%; 14.1% and 3.5% in lamas and 0%; 2.3%; 0.7% and 8.6% in alpacas, respectively. The rather low prevalence in alpacas may be associated with geographical conditions, management practices or contacts with cats rather than different species susceptibility. As expected, older animals showed higher reactivity of T. gondii than young animals.Se obtuvieron 113 sueros de llamas y 127 de alpacas de criaderos ubicados en la IX y V Regiones del país respectivamente para determinar la presencia de infección de T. gondii. Para el análisis de los sueros se utilizó el "test" modificado de aglutinación (MAT) a diluciones 1:25; 1:50, 1:500; 1:5000. Del total de 113 sueros de llamas estudiados 49 (43,3%) de ellas presentaron anticuerpos contra T. gondii, mientras que en las alpacas 15 de las 127 (11,8%) fueron positivas. El número de animales positivos en las diluciones 1/25; 1/50; 1/500; 1/5000 fue de 20 (17,6%); 9 (7,9%); 16 (10,6%); 4 (3,5%) en las llamas, respectivamente. En las alpacas los valores fueron de 0 (0%); 3 (2,3%); 1 (0,7%); 11 (8,6%), respectivamente. Aunque no existen antecedentes clínicos de la infección en los establecimientos estudiados, su potencial implicancia en este tipo de patología debería ser considerada a base de los resultados del presente trabajo que demuestra que llamas y alpacas del centro-sur de Chile son reaccionantes a la infección por T. gondii

    First reports of the invasive pest Bermudagrass Stem Maggot, Atherigona reversura Villeneuve, 1936 (Diptera: Muscidae), in South America

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    This study presents the first occurrence of Atherigona reversura in South America. This muscid, commonly known as shoot-fly, is a significant pest of cereal crops throughout the Old World tropics and subtropics. Several specimens were collected during various months in 2014 and 2015. These new records are dispersed in a wide geographical area of temperate and subtropical regions of eastern Argentina. The main host of A. reversura, the exotic bermudagrass Cynodon dactylon, is considered a pest and is widely distributed in South America.Fil: Patitucci, Luciano Damián. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Mulieri, Pablo Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: Mariluis, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin

    Characterization of Toxoplasma gondii isolates in free-range chickens from Chile, South America

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    The prevalence of Toxoplasma gondii in free-ranging chickens is a good indicator of the prevalence of T. gondii oocysts in the soil because chickens feed from the ground. The prevalence of T. gondii in 85 free-range chickens (Gallus domesticus) from Chile was determined. Antibodies to T. gondii were assayed by the modified agglutination test (MAT), and found in 47 of 85 (55.3.9%) chickens with titers of 1:5 in six, 1:10 in four, 1:20 in four 1: 40 in three, 1: 80 in nine, 1: 160 in four 1:320 in nine, and 1: 640 or higher in eight. Hearts and brains of 47 chickens with titers of 1:5 or higher were pooled for each chicken and bioassayed in mice. Tissues from 16 seronegative (MAT < 1:5) chickens were pooled and fed to one T. gondii-free cat. Feces of the cat were examined for oocysts but none was found based on bioassay of fecal floats in mice. Hearts and brains from seven seronegative (<1:5) were pooled and bioassayed in mice; T. gondii was not isolated. T. gondii was isolated by bioassay in mice from 22 chickens with MAT titers of 1:20 or higher. Genotyping of these 22 isolates using polymorphisms at the loci SAG1, SAG2, SAG3, BTUB and GRA6 revealed three genotypes. Seventeen isolates had type II alleles and four isolates had type III alleles at all loci. One isolate contained the combination of type I and III alleles. This is the first report of genetic characterization of T. gondii isolates from Chile, South America

    Survey Of Southern Amazonian Bird Helminths

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    Very little is known about the diversity, distribution, and host associations of avian helminths in southern Amazonia. The majority of avian species, families and even orders in the region have not been examined for parasitic worms so far. At the same time, the expected helminth diversity is high, given that Amazonian birds are extremely diverse and their fauna is characterized by a high level of endemism. In this work, we studied helminth fauna of birds from the westernmost region of endemism, Inambari and from the easternmost region, Belém. Two hundred and thirty-four birds belonging to 9 orders were examined for endoparasites in Inambari in November, 2013 and 199 birds belonging to 15 orders were examined in Belém in July, 2013. Birds were examined and parasites were fixed following standard endoparasite collecting protocols. Specimens were processed in the laboratory for morphological and molecular analyses. Morphology was studied on total permanent (cestodes, digeneans) or temporary (nematodes, acanthocephalans) mounts. When necessary, DNA sequences of nuclear ribosomal and mitochondrial genes were obtained to aid in species differentiation and/or phylogenetic analysis. In Inambari, 68 birds (29%) were infected with helminths. Cestodes were the most prevalent group of parasites. They were found in 42 birds (18%), followed by digeneans (23; 10%), nematodes (12; 5%) and acanthocephalans (2; 1%). In Belém, 51 birds (26%) were infected with helminths. Prevalence of infection with nematodes (28 birds; 14%) was nearly equal to that of cestodes (26; 13%), followed by digeneans (7; 4%) and acanthocephalans (6; 3%). The prevalence of infection with digeneans in Inambari was more than twice higher than in Belém which can be explained by the close proximity of Inambari collecting sites to water bodies. Taxonomic diversity and distribution of helminths among systematic and ecological groups of birds are discussed. Our study revealed several new species belonging to the families Brachylaimidae, Diplostomidae, Renschtrematidae and a likely new genus of the Schistosomatidae. Among other notable discoveries, Mesocestoides tethrathiridia have been found for the first time in South American birds. DNA sequences obtained in our study have been incorporated into broader phylogenetic analyses of corresponding groups. The resulting phylogenies are discussed

    Gender and Programming Language Preferences of Computer Programming Students at Moraine Valley Community College

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    The objectives of this study were to answer the following questions: 1. Are female programming students more likely to pursue study in certain programming languages than in other languages? 2. Are females more or less likely to pursue study in multiple programming languages than males? 3. As compared with the percentage of females working as computer programmers nationwide, are females over- or under-represented in certain language tracks at Moraine Valley Community College? 4. Which language(s) might be useful in attracting more females to computer programming and software development

    Monitoring of cfrp-strengthened reinforced concrete bridge spans in low temperature conditions

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    The article discusses strengthening bridges using composite materials at extreme low temperatures. Provides the results some experimental studies FRP strengthened concrete samples at low temperatures
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