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Sample records for argentinian bufonid toads

  1. Male size does not correlate with fertilization success in two bufonid toads that show size-assortative mating

    OpenAIRE

    Xiao-Li FAN, Zhi-Hua LIN, Xiang JI

    2013-01-01

    We examined sexual size dimorphism (SSD), mating pattern, fertilization efficiency and female reproductive traits in two bufonid toads (Bufo gargarizans and Duttaphrynus melanostictus) to test the idea that importance of male body size for egg fertilization success depends on the mating pattern. Female-biased SSD was evident only in D. melanostictus. Female B. gargarizans laid fewer larger eggs nearly three months earlier than did female D. melanostictus. Fertilization efficiencies on average...

  2. Male size does not correlate with fertilization success in two bufonid toads that show size-assortative mating

    Directory of Open Access Journals (Sweden)

    Xiao-Li FAN, Zhi-Hua LIN, Xiang JI

    2013-12-01

    Full Text Available We examined sexual size dimorphism (SSD, mating pattern, fertilization efficiency and female reproductive traits in two bufonid toads (Bufo gargarizans and Duttaphrynus melanostictus to test the idea that importance of male body size for egg fertilization success depends on the mating pattern. Female-biased SSD was evident only in D. melanostictus. Female B. gargarizans laid fewer larger eggs nearly three months earlier than did female D. melanostictus. Fertilization efficiencies on average were higher in B. gargarizans (95% than in D. melanostictus (91%. Though differing in the degree of SSD, body size, breeding season, clutch size, egg size and fertilization efficiency, the two toads were similar in four aspects: (1 both showed size-assortative mating; (2 females did not tradeoff egg size against egg number; (3 male size, clutch size and clutch dry mass were greater in male-larger than in female-larger pairs after accounting for female snout-vent length (SVL; and (4 the ratio of male to female SVL did not affect fertilization efficiency. Our data show that: (1 a female preference for large males is likely not important in terms of egg fertilization success; (2 a male preference for large females is likely important because larger females are more fecund; and (3 size-assortative mating arises from a male preference for large females. Our study demonstrates that male size is not always important for egg fertilization success in anurans that show size-assortative mating [Current Zoology 59 (6: 740–746, 2013].

  3. Biological activities of skin and parotoid gland secretions of bufonid toads (Bufo bufo, Bufo verrucosissimus and Bufotes variabilis) from Turkey.

    Science.gov (United States)

    Nalbantsoy, Ayse; Karış, Mert; Yalcin, Husniye Tansel; Göçmen, Bayram

    2016-05-01

    Toad glandular secretions and skin extractions contain numerous natural agents which may provide unique resources for novel drug development. Especially the skin-parotoid gland secretions of toads from genus Bufo contain as many as 86 different types of active compounds, each with the potential of becoming a potent drug. In the present study, crude skin-parotoid gland secretions from Bufo bufo, Bufo verrucosissimus and Bufotes variabilis from Turkey were screened against various cancer cells together with normal cells using MTT assay. Furthermore, the antimicrobial properties of skin secretions were tested on selected bacterial and fungal species for assessing the possible medical applications. Antimicrobial activity of skin secretions was studied by determining minimal inhibitory concentration (MIC) in broth dilution method. Hemolytic activity of each skin-secretion was also estimated for evaluating pharmaceutical potential. Both skin-parotoid gland secretions showed high cytotoxic effect on all cancerous and non-cancerous cell lines with IC50 values varying between cancer and antimicrobial agents without hemolytic activities. PMID:27133069

  4. Niche overlap and resource partitioning among five sympatric bufonids (Anura, Bufonidae from northeastern Argentina

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    Marta I. Duré

    2009-07-01

    Full Text Available The niche overlap and resource partitioning were analyzed for five sympatric bufonids from Northeastern Argentina: Rhinella schneideri, R. bergi, R. fernandezae, R. granulosa, and Melanophryniscus cupreuscapularis. The primary objectives were to analyze the diet and pattern of coexistence relative to the microhabitats among species. The bufonids, which are primarily terrestrial, exhibited a preference for small, hard prey such as formicids or coleopterans. The smallest species preferably consumed ants, while R. schneideri preferred beetles. Significant differences were detected for the diets of these five species. In addition, significant overlap in the trophic niche was noted for all species except between R. granulosa and R. schneideri. Studying the diet behaviors and trophic parameters of sympatric species provides important data for understandingthe community and for the development of conservation guidelines.

  5. Localization of water channels in the skin of two species of desert toads, Anaxyrus (Bufo) punctatus and Incilius (Bufo) alvarius.

    Science.gov (United States)

    Shibata, Yuki; Takeuchi, Hiro-Aki; Hasegawa, Takahiro; Suzuki, Masakazu; Tanaka, Shigeyasu; Hillyard, Stanley D; Nagai, Takatoshi

    2011-09-01

    Anuran amphibians obtain water by osmosis across their ventral skin. A specialized region in the pelvic skin of semiterrestrial species, termed the seat patch, contains aquaporins (AQPs) that become inserted into the apical plasma membrane of the epidermis following stimulation by arginine vasotocin (AVT) to facilitate rehydration. Two AVT-stimulated AQPs, AQP-h2 and AQP-h3, have been identified in the epidermis of seat patch skin of the Japanese tree frog, Hyla japonica, and show a high degree of homology with those of bufonid species. We used antibodies raised against AQP-h2 and AQP-h3 to characterize the expression of homologous AQPs in the skin of two species of toads that inhabit arid desert regions of southwestern North America. Western blot analysis of proteins gave positive results for AQP-h2-like proteins in the pelvic skin and also the urinary bladder of Anaxyrus (Bufo) punctatus while AQP-h3-like proteins were found in extracts from the pelvic skin and the more anterior ventral skin, but not the urinary bladder. Immunohistochemical observations showed both AQP-h2- and AQP-h3-like proteins were present in the apical membrane of skin from the pelvic skin of hydrated and dehydrated A. punctatus. Further stimulation by AVT or isoproterenol treatment of living toads was not evident. In contrast, skin from hydrated Incilius (Bufo) alvarius showed very weak labeling of AQP-h2- and AQP-h3-like proteins and labeling turned intense following stimulation by AVT. These results are similar to those of tree frogs and toads that occupy mesic habitats and suggest this pattern of AQP expression is the result of phylogenetic factors shared by hylid and bufonid anurans. PMID:21882955

  6. First occurrence of tetrodotoxin in a dendrobatid frog (Colostethus inguinalis), with further reports for the bufonid genus Atelopus.

    Science.gov (United States)

    Daly, J W; Gusovsky, F; Myers, C W; Yotsu-Yamashita, M; Yasumoto, T

    1994-03-01

    The water-soluble toxin present in skin of Colostethus inguinalis (Dendrobatidae) was identified as tetrodotoxin by fluorometric HPLC analysis. The amount of tetrodotoxin per frog skin was estimated by HPLC, mouse toxicity, and inhibition of [3H]saxitoxin binding to brain membranes as 0.1 to 1.2 micrograms. Small amounts of anhydrotetrodotoxin and 4-epietrodotoxin also were present. Tetrodotoxin-like activity was not detected by inhibition of [3H]saxitoxin binding in other species of Colostethus nor in other dendrobatids (Aromobates, Dendrobates, Phyllobates). Tetrodotoxin-like activity was present in extracts of skin of five species of Atelopus (Bufonidae). HPLC analysis identified tetrodotoxin as the major toxic component in Atelopus spumarius and A. varius, as a minor component in A. spurrelli, and as a trace component in A. ignescens and A. zeteki. The major tetrodotoxin-like compounds in the last three species were not identified. Tetrodotoxin-like activity was not detected by inhibition of [3H]saxitoxin binding in skin extracts from three other genera of bufonids. PMID:8016850

  7. Chloride channels in toad skin

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Rasmussen, B E

    1982-01-01

    A study of the voltage and time dependence of a transepithelial Cl- current in toad skin (Bufo bufo) by the voltage-clamp method leads to the conclusion that potential has a dual role for Cl- transport. One is to control the permeability of an apical membrane Cl-pathway, the other is to drive Cl-...... that Cl- transport through open channels does not obey the constant-field equation....

  8. Isolation of morphine from toad skin.

    OpenAIRE

    Oka, K.; Kantrowitz, J D; Spector, S

    1985-01-01

    A nonpeptide opioid was found in toad skin and purified to homogeneity by using HPLC with electrochemical detection. A nonpeptide opioid also was detected in bovine brain and adrenals as well as rabbit and rat skin, by reversed-phase HPLC following Sephadex G-15 column chromatography. The material in toad skin was identical to morphine by immunological, pharmacological, and physical chemical criteria.

  9. Genetic polymorphism of milk protein loci in Argentinian Holstein cattle

    OpenAIRE

    2000-01-01

    Some alleles of milk protein loci are associated with superior cheese production characteristics. The genetic polymorphism of the milk protein loci alphas1-casein, beta-casein, k-casein and beta-lactoglobulin was examined in Argentinian Holstein cattle. Samples from 12 herds of four regions of Córdoba were analyzed by starch gel electrophoresis. The chi² test was used to assess whether the populations were in Hardy-Weinberg equilibrium. Genotypic diversity was analyzed by the Shannon-Weaver i...

  10. Visual optics in toads (Bufo americanus).

    Science.gov (United States)

    Mathis, U; Schaeffel, F; Howland, H C

    1988-06-01

    Aspects of visual optics were investigated in the American toad (Bufo americanus). The development of the refractive state of the eye during metamorphosis was followed with IR photoretinoscopy. Frozen sections documented the changes in optical parameters before and after metamorphosis. There is a difference in light sensitivity between juvenile and adult toads. Binocular accommodation in adult toads was observed. 1. IR photoretinoscopic measurements showed that the refractive state of the eye changed very rapidly during metamorphosis, about 10 D/h while the animal entered the terrestrial habitat. 2. Frozen sections showed that the almost spherical lens in a tadpole eye had flattened in a just metamorphosed toad's eye while at the same time the distance of the lens to the retina had decreased. However, the morphological measurements were not sufficiently sensitive to record the relatively small changes in ocular dimensions that were responsible for the rapid changes in refractive state during metamorphosis. 3. Schematic eyes, with homogeneous and non homogeneous lenses, were constructed for tadpoles, juvenile toads, and adult toads. 4. Nonparaxial raytracing studies in schematic eyes suggested that the lenses of animals of the three developmental stages tadpole, juvenile toad, and adult are not homogeneous but have a refractive index gradient. The raytracing studies indicated that the refractive index gradient is different for the different developmental stages, being highest in the tadpole lens. 5. The observations of toads during feeding behavior at different light levels showed an increased light sensitivity in the adult nocturnal toads in contrast to the juvenile animals, which are diurnal. The increased light sensitivity could partly be explained with an increase in aperture and an increase in red rod outer segments. To fully explain the higher light sensitivity in adult toads, changes in neuronal parameters had to be assumed. 6. Retinoscopic measurements of

  11. critical habitat designated for the arroyo toad

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These data identify the areas (in general) of critical habitat designated for the arroyo toad. NOTE: THIS DATA SET INCLUDES APPROXIMATELY 900 ACRES OF LAND...

  12. Toad envenoming in dogs: effects and treatment

    OpenAIRE

    M. SAKATE; P. C. Lucas de Oliveira

    2000-01-01

    Toads (order: Anura; family: Bufonidae; genus: Bufo) are distributed throughout the world, but more species are found in areas of tropical and humid temperate climates. Although toads do not have a venom inoculation system, they are venomous animals because the glands covering the whole surface of their bodies secrete a milk-like venom of which composition is not yet completely known. Some of these glands are the bilateral glands located in post-orbital position. These glands, which are somew...

  13. INFLUENCE OF GM SOY EXPANSION ON THE ARGENTINIAN FOOD AND NUTRITION SECURITY

    OpenAIRE

    Zanasi, Cesare; Rota, Cosimo; Severi, Claudia; Demadonna, Anna

    2015-01-01

    The rapid expansion of Argentinian soy production, led by the increase in the international soy demand for food feed and biofuel production, deeply influenced the entire Argentinian society economy and environment. Genetically modified soy has become a strategic product for the Latin American country, strongly supporting the entire economy and the welfare state thanks to the income derived from soy production and export taxations. The influence of the GM soy production strongly modified in pa...

  14. Sulfate transport in toad skin

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Simonsen, K

    1988-01-01

    1. In short-circuited toad skin preparations exposed bilaterally to NaCl-Ringer's containing 1 mM SO2(-4), influx of sulfate was larger than efflux showing that the skin is capable of transporting sulfate actively in an inward direction. 2. This active transport was not abolished by substituting...... apical Na+ for K+. 3. Following voltage activation of the passive Cl- permeability of the mitochondria-rich (m.r.) cells sulfate flux-ratio increased to a value predicted from the Ussing flux-ratio equation for a monovalent anion. 4. In such skins, which were shown to exhibit vanishingly small leakage...... conductances, the variation of the rate coefficient for sulfate influx (y) was positively correlated with the rate coefficient for Cl- influx (x), y = 0.035 x - 0.0077 cm/sec (r = 0.9935, n = 15). 5. Addition of the phosphodiesterase inhibitor, 3-isobutyl-1-methyl-xanthine to the serosal bath of short...

  15. Genetic polymorphism of milk protein loci in Argentinian Holstein cattle

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    Bonvillani Adriana Gloria

    2000-01-01

    Full Text Available Some alleles of milk protein loci are associated with superior cheese production characteristics. The genetic polymorphism of the milk protein loci alphas1-casein, beta-casein, k-casein and beta-lactoglobulin was examined in Argentinian Holstein cattle. Samples from 12 herds of four regions of Córdoba were analyzed by starch gel electrophoresis. The chi² test was used to assess whether the populations were in Hardy-Weinberg equilibrium. Genotypic diversity was analyzed by the Shannon-Weaver index. The observed genotypic frequencies were analyzed by Hedrick's genetic identity and the genetic distance of Balakrishnan and Sanghvi. The allelic and genotypic frequencies were similar to those of other Holstein populations. The genotypic frequencies of the alphas1-casein and beta-casein loci were in equilibrium, whereas in some populations the k-casein and beta-lactoglobulin loci were not. According to the Shannon-Weaver index the total genetic diversity within each herd was greater than 96%. The high values of identity agreed with the low genetic distances among populations. We conclude that there is extensive genetic homogeneity in Holstein cattle in Córdoba Province and that it would be feasible to select for B alleles at the k-casein and b-lactoglobulin loci in order to improve the quality of milk available for cheese manufacturing.

  16. Toad poisoning in three dogs: case reports

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    CM Barbosa

    2009-01-01

    Full Text Available Toad poisoning is frequent in dogs, but has been infrequently addressed in published case reports and review articles. Dogs can be poisoned when they bite a toad or otherwise ingest the venom. The venom effects manifest soon after the accident, since the toxin is rapidly absorbed by the mucous membrane of the digestive system. Hospital records of three dogs, diagnosed with toad poisoning, were retrospectively reviewed from January 2005 to July 2007. Poisoned dogs may present only local irritation or systemic signs in the gastrointestinal, cardiac and neurological systems. All three cases presented herein had clinical signs of gastrointestinal alterations including vomiting, sialorrhea and diarrhea. Two dogs developed abnormal cardiac rhythm and two exhibited neurological signs. A poisoned animal requires emergency care and symptomatic therapy with intense monitoring of its clinical parameters. Although there have been reports on the low mortality of dogs poisoned by toads, one animal died even after appropriate therapy. The severity of clinical signs and the risk of death must be considered by the veterinarian.

  17. Immunolocation of mitochondria-rich cells in epidermis of the common toad, Bufo bufo L

    DEFF Research Database (Denmark)

    Spies, Ingrid B.M.

    Adult toads, skin, flask-shaped cells, cytoskeleton, keratin expression, immunohistochemistry, differentiation.......Adult toads, skin, flask-shaped cells, cytoskeleton, keratin expression, immunohistochemistry, differentiation....

  18. The Construction of National Memory Through Popular Culture. The Case of the Argentinian TV Show,

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    Elizondo Oviedo, María Verónica

    2010-07-01

    Full Text Available This article addresses the borders of the complex television sign through the analysis of the Argentinian TV show "Peter Capusotto y sus videos". In it we find that humor is used as a mechanism to dismantle binary hierarchic political and social oppositions. The program is presented as a musical and comedy TV show where concepts such as popular culture and mass culture are questioned through different false musicians. We focus our attention in the character of Bombita Rodríguez, el Palito Ortega montonero due to the controversy generated in the cultural scene by the fact of bringing up recent aspects of Argentinian history.

  19. Toads on Lava: Spatial Ecology and Habitat Use of Invasive Cane Toads (Rhinella marina) in Hawai’i

    OpenAIRE

    Georgia Ward-Fear; Greenlees, Matthew J.; Richard Shine

    2016-01-01

    Most ecological research on cane toads (Rhinella marina) has focused on invasive populations in Australia, ignoring other areas where toads have been introduced. We radio-tracked and spool-tracked 40 toads, from four populations on the island of Hawai'i. Toads moved extensively at night (mean 116 m, from spool-tracking) but returned to the same or a nearby retreat-site each day (from radio-tracking, mean distance between successive retreat sites 11 m; 0 m for 70% of records). Males followed s...

  20. Wild Argentinian Amaryllidaceae, a New Renewable Source of the Acetylcholinesterase Inhibitor Galanthamine and Other Alkaloids

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    Gabriela E. Feresin

    2012-11-01

    Full Text Available The Amaryllidaceae family is well known for its pharmacologically active alkaloids. An important approach to treat Alzheimer’s disease involves the inhibition of the enzyme acetylcholinesterase (AChE. Galanthamine, an Amaryllidaceae alkaloid, is an effective, selective, reversible, and competitive AchE inhibitor. This work was aimed at studying the alkaloid composition of four wild Argentinian Amarillydaceae species for the first time, as well as analyzing their inhibitory activity on acetylcholinesterase. Alkaloid content was characterized by means of GC-MS analysis. Chloroform basic extracts from Habranthus jamesonii, Phycella herbertiana, Rhodophiala mendocina and Zephyranthes filifolia collected in the Argentinian Andean region all contained galanthamine, and showed a strong AChE inhibitory activity (IC50 between 1.2 and 2 µg/mL. To our knowledge, no previous reports on alkaloid profiles and AChEIs activity of wild Argentinian Amarillydaceae species have been publisihed. The demand for renewable sources of industrial products like galanthamine and the need to protect plant biodiversity creates an opportunity for Argentinian farmers to produce such crops.

  1. Toads on Lava: Spatial Ecology and Habitat Use of Invasive Cane Toads (Rhinella marina in Hawai'i.

    Directory of Open Access Journals (Sweden)

    Georgia Ward-Fear

    Full Text Available Most ecological research on cane toads (Rhinella marina has focused on invasive populations in Australia, ignoring other areas where toads have been introduced. We radio-tracked and spool-tracked 40 toads, from four populations on the island of Hawai'i. Toads moved extensively at night (mean 116 m, from spool-tracking but returned to the same or a nearby retreat-site each day (from radio-tracking, mean distance between successive retreat sites 11 m; 0 m for 70% of records. Males followed straighter paths during nocturnal movements than did females. Because moist sites are scarce on the highly porous lava substrate, Hawai'ian toads depend on anthropogenic disturbance for shelter (e.g. beneath buildings, foraging (e.g. suburban lawns, golf courses and breeding (artificial ponds. Foraging sites are further concentrated by a scarcity of flying insects (negating artificial lights as prey-attractors. Habitat use of toads shifted with time (at night, toads selected areas with less bare ground, canopy, understory and leaf-litter, and differed between sexes (females foraged in areas of bare ground with dense understory vegetation. Cane toads in Hawai'i thrive in scattered moist patches within a severely arid matrix, despite a scarcity of flying insects, testifying to the species' ability to exploit anthropogenic disturbance.

  2. Toads on Lava: Spatial Ecology and Habitat Use of Invasive Cane Toads (Rhinella marina) in Hawai’i

    Science.gov (United States)

    Ward-Fear, Georgia; Greenlees, Matthew J.; Shine, Richard

    2016-01-01

    Most ecological research on cane toads (Rhinella marina) has focused on invasive populations in Australia, ignoring other areas where toads have been introduced. We radio-tracked and spool-tracked 40 toads, from four populations on the island of Hawai’i. Toads moved extensively at night (mean 116 m, from spool-tracking) but returned to the same or a nearby retreat-site each day (from radio-tracking, mean distance between successive retreat sites 11 m; 0 m for 70% of records). Males followed straighter paths during nocturnal movements than did females. Because moist sites are scarce on the highly porous lava substrate, Hawai’ian toads depend on anthropogenic disturbance for shelter (e.g. beneath buildings), foraging (e.g. suburban lawns, golf courses) and breeding (artificial ponds). Foraging sites are further concentrated by a scarcity of flying insects (negating artificial lights as prey-attractors). Habitat use of toads shifted with time (at night, toads selected areas with less bare ground, canopy, understory and leaf-litter), and differed between sexes (females foraged in areas of bare ground with dense understory vegetation). Cane toads in Hawai’i thrive in scattered moist patches within a severely arid matrix, despite a scarcity of flying insects, testifying to the species’ ability to exploit anthropogenic disturbance. PMID:27027738

  3. Radiosensitivity of the Philippine giant toad (Bufu marinus L.)

    International Nuclear Information System (INIS)

    The Philippine giant toad (Bufu marinus L.) were studied to establish their radiosensitivities and their possible use as a good biological indicator organism of radiation effects. Live male and female toads were exposed to ionizing doses of gamma irradiation. Chromosome analysis was done under the Carl Zeiss III photo microscope. Somatic and meiotic chromosome aberrations were induced in giant toad upon in vivo whole gamma irradiations. By cytogenetic analysis the aberrant chromosomes were observed and evaluated. In these studies, it was concluded that Bufo marinus L. is significantly radiosensitive and a good biological indicator organisms of radiation effects. (ISD). 2 figs.; 8 tabs

  4. The late Oligocene flora from the Río Leona Formation, Argentinian Patagonia

    OpenAIRE

    Césari, Silvia N.; Panti, Carolina; Roberto R Pujana; Francis, Jane E.; Sergio A Marenssi

    2015-01-01

    A late Oligocene plant macrofossil assemblage is described from the Río Leona Formation, Argentinian Patagonia. This includes a fern, “Blechnum turbioensis” Frenguelli, one species of conifer, and sixteen angiosperm taxa. Rosaceae, Myrtaceae, Proteaceae, Lauraceae, Anacardiaceae and Typhaceae are represented by one species in each family. Five species are considered to be members of the Fabales. Three leaf taxa together with Carpolithus seeds are placed in the Nothofagaceae. Palynomorphs and ...

  5. Wild Argentinian Amaryllidaceae, a New Renewable Source of the Acetylcholinesterase Inhibitor Galanthamine and Other Alkaloids

    OpenAIRE

    Feresin, Gabriela E.; Jaume Bastida; Alejandro Tapia; German Roitman; Cristina Theoduloz; Strahil Berkov; Natalia B. Pigni; Javier E. Ortiz

    2012-01-01

    The Amaryllidaceae family is well known for its pharmacologically active alkaloids. An important approach to treat Alzheimer’s disease involves the inhibition of the enzyme acetylcholinesterase (AChE). Galanthamine, an Amaryllidaceae alkaloid, is an effective, selective, reversible, and competitive AchE inhibitor. This work was aimed at studying the alkaloid composition of four wild Argentinian Amarillydaceae species for the first time, as well as analyzing their inhibitory activity...

  6. Foreign Policy and Political Culture: the Case of the Argentinian Democracy (1983-1985

    Directory of Open Access Journals (Sweden)

    Ezequiel Reficco

    1996-02-01

    Full Text Available Throughout the twelve years that have passed since the restoration of democracy in Argentina, the external political dynamics of the country experienced dramatic changes. We can distinguish between three periods structured according to clearly differentiated parametres: the search for independence (1983-1985, the change to realism (1985-1989 and the search to reconnect (1989-1995.At the same time, this evolution was accompanied by far-reaching transformations in the international system. These changes were reflected through the means of an emulative connection to Argentinian political life, modifying the terms of the consensus which sustained the external dynamics of the State. Argentinian political culture had to adapt itself to reality, to its own experience and to those signals coming from enviroment which indicated where -and where notitshould direct its energies in order to optimize results.From this re-reading of reality carried out by both political leaders and Argentinian public opinion, the president elected, regardless of the result of the 1989 elections, had instrumented a reorientation similar to the present one. In the same way, Menem’s successor will maintain, in broad termes, the current external dynamics in his country.

  7. Biogeographic patterns of Colombian frogs and toads

    International Nuclear Information System (INIS)

    Using the data provided in Ruiz-Carranza et al. (1996) the distributions of the 540 species of frogs and toads are partitioned among ten ecogeographic units of Colombia defined on the basis of precipitation and elevation. Some lowlands areas (pacific lowlands, Amazonian) exhibit high diversity (85-94 species) but lowlands areas in general are impoverished (30-52 species), especially when contrasted with upland areas. The three Andean cordilleras harbor between 87 and 121 species of frogs and toads, demonstrating that the biodiversity of Colombia resides primarily in its montane components, not in its lowland rain forests. When biological endemicity is separated from political endemicity, five areas of high endemicity remain (the three Andean cordilleras, the Sierra Nevada de Santa Marta, and the pacific lowlands). We endeavor to explain this description by recourse to cladistic analyses of several groups of leptodactylid frogs where we find that the general pattern of diversification is by means of horizontal diversification (allopatric speciation) with a minor contribution from vertical diversification

  8. Thyroid anatomy and topography of toad (Bufo marinus ictericus)

    International Nuclear Information System (INIS)

    The autoradiographic method is used for the study of the toad's thyroid of Bufo marinus ictericus by 131I. Histolological proceedings are done. Comparative evaluations with bibliographic informations are presented. (M.A.C.)

  9. Final Critical Habitat for the Houston toad (Bufo houstonensis)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — To provide the user with a general idea of areas where final critical habitat for Houston toad (Bufo houstonensis) based on the description provided in the Federal...

  10. Conservation genetics of an island toad: Bufo bufo in Jersey

    OpenAIRE

    John W. Wilkinson; Trevor J C Beebee; Griffiths, Richard A.

    2007-01-01

    On Jersey (British Channel Islands), common toads often reproduce in small, urban ponds. This atypical breeding strategy has implications for their persistence and they have declined on the island in recent times. We used polymorphic microsatellite markers to compare genetic diversity in Bufo bufo from five different ponds in Jersey with two populations from north-west France. Genetic diversity of Jersey toads was comparable with that of populations elsewhere in Europe. Numbers of breeding fe...

  11. The Effect of the Ecology of Toads on the Distribution of Helminths

    OpenAIRE

    VASHETKO, Emilia V.; SIDDIKOV, Bakhodir H.

    1999-01-01

    This paper presents the results of studies on the helminth fauna of the green toad, Bufo viridis, in Uzbekistan. Twently helminth species were identified. The highest diversity of helminths was recorded in toads in the newly-built districts of Tashkent (1966-76). The helminth fauna of the toads inhabiting foothills was less common.

  12. Inadvertent Trypan Blue Staining of Posterior Capsule during Cataract Surgery Associated with “Argentinian Flag” Event

    Science.gov (United States)

    Prinzi, Robert A.; Alapati, Neeti M.; Gappy, Shawn S.; Dilly, Jason S.

    2016-01-01

    Trypan blue is common in visualizing the anterior capsule during cataract surgery. Inadvertent staining of the posterior capsule during phacoemulsification is a rare complication and there are few reports in the literature. The proposed mechanism of posterior capsule staining in previous reports includes a compromised zonular apparatus or iris retractors facilitating the posterior flow of trypan blue. We report the first case of trypan blue staining of the posterior capsule associated with the “Argentinian flag” sign. In our case, the “Argentinian flag” allowed the trypan blue to seep between the posterior capsule and the lens, staining the anterior surface of the posterior capsule. PMID:27022495

  13. The 'Prof. Dr. Rómulo Lambre' Collection: an Argentinian sample of modern skeletons.

    Science.gov (United States)

    Salceda, S A; Desántolo, B; Mancuso, R García; Plischuk, M; Inda, A M

    2012-08-01

    This paper describes the 'Prof. Dr. Rómulo Lambre' skeletal collection. The Lambre Collection is housed in the School of Medical Sciences of the National University of La Plata and it consists of skeletal remains ceded by the Municipal Cemetery of La Plata. The collection has more than four hundred skeletons, with information on age, sex, nationality, date and cause of death. It was created for teaching and research purposes in compliance with current legislation, and its management meets guidelines specified in the Declaration of the Argentinian Association for Biological Anthropology on Research Ethics on Human Remains (2007). PMID:22769855

  14. Diet composition of the invasive cane toad (Chaunus marinus) on Rota, Northern Mariana Islands

    Science.gov (United States)

    Reed, R.N.; Bakkegard, K.A.; Desy, G.E.; Plentovich, S.M.

    2007-01-01

    The cane or marine toad (Chaunus marinus, formerly Bufo marinus) was introduced to the Northern Mariana Islands starting in the 1930s. The effects of this exotic predator on native vertebrates (especially lizards) are largely unknown. We analysed the stomach contents of 336 cane toads collected from the island of Rota, with the goal of estimating the level of toad predation on native vertebrates. Beetles, ants, millipedes, and grasshoppers/crickets comprised the majority of prey classes consumed by toads. The introduced Brahminy blindsnake (Ramphotyphlops braminus; N = 6) and conspecific cane toads (N = 4) were the vertebrates most commonly found in toad stomachs. Skinks (Emoia; N = 2) were the only native vertebrates represented in our sample. The small numbers of nocturnal terrestrial vertebrates native to Rota likely translates to relatively low rates of predation by cane toads on native vertebrates.

  15. DIET OF THE SOUTHERN TOAD FROM THE SOUTHERN EVERGLADES

    Science.gov (United States)

    We examined the diet of a February-May sample of the southern toad (Bufo Terrestris) from the Everglades National Park. Above the familial level, 13 taxa were consumed, but ants (Hymenoptera) and beetles (Coleoptera) were consumed most by, and in the greatest number of s...

  16. Study of the characteristic parameters of the normal voices of Argentinian speakers

    Directory of Open Access Journals (Sweden)

    Edgardo Bonzi

    2014-02-01

    Full Text Available The voice laboratory permits to study the human voices using a method that is objective and noninvasive. In this work, we have studied the parameters of the human voice such as pitch, formant, jitter, shimmer and harmonic-noise ratio of a group of young people. This statistical information of parameters is obtained from Argentinian speakers. Received: 29 December 2013, Accepted: 27 May 2014; Reviewed by: J. Brum, Instituto de Física, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay; Edited by: E. Mizraji; DOI: http://dx.doi.org/10.4279/PIP.060002 Cite as: E V Bonzi, G B Grad, A M Maggi, M R Muñoz, Papers in Physics 6, 060002 (2014

  17. Evaluation of Argentinian industrial capacity and of suppliers for nuclear installations

    International Nuclear Information System (INIS)

    This work describes and analyses the Argentinian system of purchasing, the laws and decrees which must be observed by the State enterprises and dependent bodies such as the National Atomic Energy Commission (C.N.E.A.). Within the system there are regulations which must be observed by the State suppliers, and to which the purchasing bodies must conform. Furthermore, there is a thorough analysis of the methods implemented before beginning the construction of the third nuclear plant in Argentina, the Atucha II Nuclear Plant. For this, all the existing antecedents were taken into account, insofar as they were related to the prior projects, and an exhaustive questionnaire was elaborated, in which the examined enterprises described in detail their installed capacity, their antecedents, their human resources, etc. The data thus obtained were evaluated and the task was concluded by drawing up lists of the possible enterprises to supply the most diverse components, services or equipment required both by the electrical plant and for any other large scale work. The evaluation obtained would allow an analysis of the foreign offers concerning the entire project and of the possible participation with each bidder of Argentinian industry and engineering. A description is given of the advanced method used to assess bidders with respect to such participation, to assess the replies to the questionnaire, which were analysed in detail, and the weighting factors applied to each item. Also described are some major contracts concluded with enterprises in the country. These contracts relate to the external acquisition of technology for nuclear plants and the essential points are outlined. Also analysed are the results obtained during the execution of the programmes of technology transfer and training, both for parts of different enterprises selected to produce the components, and for the State, through C.N.E.A. and ENACE S.A. 6 refs, 5 tabs

  18. Argentinian president Cristina de Kirchner starts commissioning of Atucha II mechanical systems

    International Nuclear Information System (INIS)

    On September 28, 2011, construction of the Atucha II heavy-water reactor plant (CNA II, 745 gross MWe) in Argentina reached another important milestone on its way to completion of the project. In the presence of Argentinian State President Cristina Fernandez de Kirchner, commissioning of the mechanical systems was initiated. The technology of the Atucha reactor facilities, which are fueled with natural uranium, moderated by heavy water (D2O) and cooled by light water (H2O) (Pressurized Heavy Water Reactor, PHWR), originally was developed by Siemens. These plants were designed alongside the pressurized water reactors using light water. The strict requirements applying to advanced designs in Germany as well as current findings in technical implementation were employed. Major construction and mechanical assembly work has been completed. The primary system has been installed completely. The first core was manufactured at the Argentinian fuel element factory of Conuar and placed into the plant's dry store, which also contains the control and shutdown rods. The heavy water (D2O) needed for nuclear operation has been produced and is being stored on the plant premises. Extensive commissioning work is going on in the building for the switching systems including the main and the emergency control rooms. The turbine hall is largely complete, as are the facilities for cooling water supply. The commissioning phase of the plant has been started involving considerable manpower. Some procedures for the later part of the commissioning phase still need to be completed. As a consequence of its sound and qualified basic design and the incorporation of other, new findings, Atucha II in its optimized design will prove to be a safe and reliable plant in operation. The start of commercial operation of Atucha II has been announced for probably late 2012. (orig.)

  19. An introduced pentastomid parasite (Raillietiella frenata) infects native cane toads (Rhinella marina) in Panama.

    Science.gov (United States)

    Kelehear, Crystal; Saltonstall, Kristin; Torchin, Mark E

    2015-04-01

    The pentastomid parasite, Raillietiella frenata, is native to Asia where it infects the Asian House gecko, Hemidactylus frenatus. This gecko has been widely introduced and recently R. frenata was found in introduced populations of cane toads (Rhinella marina) in Australia, indicating a host-switch from introduced geckos to toads. Here we report non-native adult R. frenata infecting the lungs of native cane toads in Panama. Eight of 64 toads were infected (median = 2.5, range = 1-80 pentastomids/toad) and pentastomid prevalence was positively associated with the number of buildings at a site, though further sampling is needed to confirm this pattern. We postulate that this pattern is likely due to a host shift of this parasite from an urban-associated introduced gecko. This is the first record of this parasite infecting cane toads in their native range, and the first instance of this parasite occurring in Central America. PMID:25394910

  20. Shifts in life history as a response to predation in western toads (Bufo boreas)

    OpenAIRE

    Chivers, Douglas P.; Marco, Adolfo; Kiesecker, Joseph M.; Wildy, Erica L.; Andrew R. Blaustein

    1999-01-01

    Larval western toads (Bufo boreas) are known to exhibit antipreda­ tor behavior in response to both chemical alarm cues released from injured conspecifics and chemical cues of predatory invertebrates. In this study, we tested whether long-term exposure to predator and alarm cues resulted in an adaptive shift in life history characteristics of the toads. We raised groups of tadpoles in the presence of: (1) predatory backswimmers (Notonecta spp.) that were fed toad tadpoles, (2) nonpredatory w...

  1. Travelling waves for the cane toads equation with bounded traits

    International Nuclear Information System (INIS)

    In this paper, we study propagation in a non-local reaction–diffusion–mutation model describing the invasion of cane toads in Australia (Phillips et al 2006 Nature 439 803). The population of toads is structured by a space variable and a phenotypical trait and the space diffusivity depends on the trait. We use a Schauder topological degree argument for the construction of some travelling wave solutions of the model. The speed c* of the wave is obtained after solving a suitable spectral problem in the trait variable. An eigenvector arising from this eigenvalue problem gives the flavour of the profile at the edge of the front. The major difficulty is to obtain uniform L∞ bounds despite the combination of non-local terms and a heterogeneous diffusivity. (paper)

  2. Travelling waves for the cane toads equation with bounded traits

    Science.gov (United States)

    Bouin, Emeric; Calvez, Vincent

    2014-09-01

    In this paper, we study propagation in a non-local reaction-diffusion-mutation model describing the invasion of cane toads in Australia (Phillips et al 2006 Nature 439 803). The population of toads is structured by a space variable and a phenotypical trait and the space diffusivity depends on the trait. We use a Schauder topological degree argument for the construction of some travelling wave solutions of the model. The speed c* of the wave is obtained after solving a suitable spectral problem in the trait variable. An eigenvector arising from this eigenvalue problem gives the flavour of the profile at the edge of the front. The major difficulty is to obtain uniform L∞ bounds despite the combination of non-local terms and a heterogeneous diffusivity.

  3. SEXUAL DIFFERENCES IN THE ECOLOGY AND HABITAT SELECTION OF WESTERN TOADS (BUFO BOREAS IN NORTHEASTERN OREGON

    Directory of Open Access Journals (Sweden)

    EVELYN L. BULL

    2006-09-01

    Full Text Available Several species of toads (family Bufonidae, including the Western Toad (Bufo boreas have declined in thewestern United States. Information on toad ecology and habitat use is essential to determine potential causes for populationdeclines, as is the potential relationship between this information and disturbance events. Aspects of western toad survival,mortality, movements, habitat selection, and diet were investigated at five study areas in northeastern Oregon duringsummers of 2002-2005. Of 100 radio-tagged toads monitored for one summer during these years, 32% survived untilSeptember, 29% were killed by predators, 10% died of other causes, and 29% were missing or had lost transmitters. Atfour study areas sampled in 2005, 24% of 37 males and 44% of 32 females sampled during the breeding season, and threedead male toads found after the breeding season tested positive for Batrachochytrium dendrobatidis. Females traveledsignificantly farther than males, and the maximum distances traveled by female and male toads were 6230 m and 3870 m,respectively. Toads with transmitters selected habitats: (1 with little or no canopy; (2 on south-facing slopes; (3 nearwater; and (4 with high densities of potential refugia (e.g., burrows, rocks, logs. Males were more closely associated withwater than females. Twenty-six toads overwintered in rodent burrows (38%, under large rocks (27%, under logs or rootwads (19%, and under banks adjacent to streams or a lake (15%. Diet consisted of 82% ants (Formicidae, 13% beetles(Coleoptera, and <1% in 8 additional orders of insects with no differences detected between male and female toads.Disturbance events, such as wildfire, can influence refugia and prey of toads, and climatic conditions may influence a toad’ssusceptibility to B. dendrobatidis.

  4. Habitat use and movement of the endangered Arroyo Toad (Anaxyrus californicus) in coastal southern California

    Science.gov (United States)

    Gallegos, Elizabeth; Lyren, Lisa M.; Lovich, Robert E.; Mitrovich, Milan J.; Fisher, Robert N.

    2011-01-01

    Information on the habitat use and movement patterns of Arroyo Toads (Anaxyrus californicus) is limited. The temporal and spatial characteristics of terrestrial habitat use, especially as it relates to upland use in coastal areas of the species' range, are poorly understood. We present analyses of radiotelemetry data from 40 individual adult toads tracked at a single site in coastal southern California from March through November of 2004. We quantify adult Arroyo Toad habitat use and movements and interpret results in the context of their life history. We show concentrated activity by both male and female toads along stream terraces during and after breeding, and, although our fall sample size is low, the continued presence of adult toads in the floodplain through the late fall. Adult toads used open sandy flats with sparse vegetation. Home-range size and movement frequency varied as a function of body mass. Observed spatial patterns of movement and habitat use both during and outside of the breeding period as well as available climatological data suggest that overwintering of toads in floodplain habitats of near-coastal areas of southern California may be more common than previously considered. If adult toads are not migrating out of the floodplain at the close of the breeding season but instead overwinter on stream terraces in near-coastal areas, then current management practices that assume toad absence from floodplain habitats may be leaving adult toads over-wintering on stream terraces vulnerable to human disturbance during a time of year when Arroyo Toad mortality is potentially highest.

  5. Microelectronic neural bridging of toad nerves to restore leg function☆

    OpenAIRE

    Shen, Xiaoyan; Wang, Zhigong; Lv, Xiaoying; Huang, Zonghao

    2013-01-01

    The present study used a microelectronic neural bridge comprised of electrode arrays for neural signal detection, functional electrical stimulation, and a microelectronic circuit including signal amplifying, processing, and functional electrical stimulation to bridge two separate nerves, and to restore the lost function of one nerve. The left leg of one spinal toad was subjected to external mechanical stimulation and functional electrical stimulation driving. The function of the left leg of o...

  6. Diazinon mediated biochemical changes in the African toad (Bufo regularis

    Directory of Open Access Journals (Sweden)

    Isioma Tongo

    2012-07-01

    Full Text Available The sublethal toxicity of diazinon to the adult African toad, Bufo regularis was assessed using an integration of biomarkers. Changes in acetylcholinesterase (AChE, corticosterone and total protein levels were assessed in the serum, brain, liver, lungs and gastrointestinal tract (GIT and the results supported by bioaccumulation data. The biomarkers were chosen as indicators of key physiological functions: AChE for neurotoxicity, corticosterone and total protein levels as indicators of oxidative stress. Toads were exposed to 0.01, 0.02, 0.03 and 0.04 g/L for 28 days. Brain AChE activity reduced by 96% in the highest concentration (0.04 g/L compared to the control brain. Similarly, AChE activities in serum, liver, lungs and GIT tissues (88%, 88%, 87, 87% umg-1 protein respectively were also inhibited in the toads. Corticosterone and total protein levels in the tissues decreased compared to the control. The accumulation results obtained showed accumulation in the tissues (liver>serum>brain> lung>GIT, with a direct relationship between tissue concentration and changes in the biochemical indices. The alterations in all the indices were significantly concentration dependent. The biomarkers described in this study could be useful complementary indices in the risk assessment of diazinon pesticide.

  7. Phospholipid transfer activities in toad oocytes and developing embryos

    International Nuclear Information System (INIS)

    The role of lipid transfer proteins during plasma membrane biogenesis was explored. Developing amphibia embryos were used because during their growth an active plasma membrane biosynthesis occurs together with negligible mitochondrial and endoplasmic reticulum proliferation. Sonicated vesicles, containing 14C-labeled phospholipids and 3H-labeled triolein, as donor particles and cross-linked erythrocyte ghosts as acceptor particles were used to measure phospholipid transfer activities in unfertilized oocytes and in developing embryos of the toad Bufo arenarum. Phosphatidylcholine transfer activity in pH 5.1 supernatant of unfertilized oocytes was 8-fold higher than the activity found in female toad liver supernatant, but dropped steadily after fertilization. After 20 hr of development, at the stage of late blastula, the phosphatidylcholine transfer activity had dropped 4-fold. Unfertilized oocyte supernatant exhibited phosphatidylinositol and phosphatidylethanolamine transfer activity also, but at the late blastula stage the former had dropped 18-fold and the latter was no longer detectable under our assay conditions. Our results show that fertilization does not trigger a phospholipid transport process catalyzed by lipid transfer proteins. Moreover, they imply that 75% of the phosphatidylcholine transfer activity and more than 95% of the phosphatidylinositol and phosphatidylethanolamine transfer activities present in pH 5.1 supernatants of unfertilized oocytes may not be essential for toad embryo development. Our findings do not rule out, however, that a phosphatidylcholine-specific lipid transfer protein could be required for embryo early growth

  8. Novel IFT122 mutations in three Argentinian patients with cranioectodermal dysplasia: Expanding the mutational spectrum.

    Science.gov (United States)

    Moosa, Shahida; Obregon, Maria Gabriela; Altmüller, Janine; Thiele, Holger; Nürnberg, Peter; Fano, Virginia; Wollnik, Bernd

    2016-05-01

    Cranioectodermal dysplasia (CED), also known as Sensenbrenner syndrome, is an autosomal recessive ciliary chondrodysplasia characterized by a recognizable craniofacial gestalt, skeletal abnormalities, and ectodermal features. To date, four genes have been shown to underlie the syndrome, namely, IFT122 (WDR10), WDR35 (IFT121), IFT43 (C14orf179), and WDR19 (IFT144). Clinical characterization of a larger cohort of patients with CED has been undertaken previously. Nevertheless, there are too few molecularly confirmed patients reported in the literature to determine precise genotype-phenotype correlations. To date, biallelic IFT122 mutations have been described in only five families. We therefore studied three unrelated Argentinian patients with typical features of CED using a 4813 next-generation sequencing (NGS) gene panel, which we call the "Mendeliome." The three patients had different, novel, compound heterozygous mutations in IFT122. Consequently, we compared these three patients to those previously described with IFT122 mutations. Thus, our report serves to add 6 novel mutations to the IFT122 mutation spectrum and to contribute to the IFT122-related clinical characterization. © 2016 Wiley Periodicals, Inc. PMID:26792575

  9. Insights into ecological and reproductive aspects of two cryptogenic peracarid crustaceans of the Argentinian coast

    Directory of Open Access Journals (Sweden)

    Anna Fricke

    2015-09-01

    Full Text Available AbstractPeracarid crustaceans belong to the most important agglomerating macrofauna in sedimentary habitats. The amphipod Monocorophium insidiosumCRAWFORD, 1937 and the tanaid Tanais dulongii AUDOUIN, 1926 are listed as invasive species. In the present study, we investigated the ecology of M. insidiosum and T. aff. dulongii from the Argentinian coast. Both crustaceans were breeding under laboratory conditions to study their fecundity and growth. Additionally their behavior and potential interspecific relations have been investigated in four different laboratory experiments. We evaluated tube building capabilities (experiment 1, and tested gender specific responses of M. insdiosum to the presence of empty (experiments 2 and 3, and inhabited T. aff. dulongii tubes (experiment 4. Our results showed high fecundity (three generations within four weeks and growth rates (duplication of body lengths in two weeks for M. insidiosum. Two tube construction strategies were distinguished: a tube changing behavior for the amphipod M. insidiosum, showing greater construction activity for females, and tube keeping behavior for T. aff. dulongii. Overall, tanaid tubes were frequently claimed by M. insidiosum, demonstrating a close interspecific relationship and resulting in decreased sediment aggregating activity. In the light of our observations it may be affirmed that these invasive species are probably frequently distributed along the Patagonian Atlantic coast and will still spread in future.

  10. Serum and hepatic vitamin A levels in captive and wild marine toads (Bufo marinus).

    Science.gov (United States)

    Berkvens, Charlene N; Lentini, Andrew; Dutton, Christopher J; Pearl, David L; Barker, Ian K; Crawshaw, Graham J

    2014-01-01

    The captive breeding program for the endangered Puerto Rican crested toad (Peltophryne [Bufo] lemur) has been hampered by an undiagnosed condition called "Brown Skin Disease" (BSD). Toads develop widespread skin darkening, skin thickening and abnormal shedding and eventually succumb to a chronic loss of viability. This project evaluated the marine toad (Bufo marinus) as a model for the PRCT, examining vitamin A deficiency as a potential cause of BSD. Wild caught marine toads had significantly higher liver vitamin A concentrations (61.89 ± 63.49 µg/g) than captive born marine toads (0.58 ± 0.59 µg/g); P<0.001). A significant difference in serum vitamin A concentration was found between the captive and wild caught toads (P=0.013) and between the low vitamin A-fed and wild caught toads (P=0.004), when controlling for liver vitamin A concentrations. After captive toads were treated with topical and/or oral vitamin A, their hepatic vitamin A concentrations were similar to those of the wild toads, averaging 48.41 ± 37.03 µg/g. However, plasma vitamin A concentrations pre- and post-vitamin A supplementation did not differ statistically. We concluded that plasma vitamin A concentrations do not provide a linear indication of liver/body vitamin A status, and that both topical and oral supplementation with an oil-based vitamin A formulation can increase liver stores in amphibians. No evidence of BSD or other signs of deficiency were noted in the marine toads, although this feeding trial was relatively short (127 days). To date, clinical, pathological and research findings do not support vitamin A deficiency as a primary factor underlying BSD. PMID:25230391

  11. Adrenocortical function in cane toads from different environments.

    Science.gov (United States)

    Hernández, Sandra E; Sernia, Conrad; Bradley, Adrian J

    2016-05-01

    The adrenocortical function of cane toads (Rhinella marina) exposed to different experimental procedures, as well as captured from different environments, was assessed by challenging the hypothalamic-pituitary-adrenal (HPA) axis. It was found that restriction stress as well as cannulation increased plasma corticosterone (B) levels for up to 12h. A single dose of dexamethasone (DEX 2mg/kg) significantly reduced B levels demonstrating its potential for use in the evaluation of the HPA axis in amphibia. We also demonstrate that 0.05 IU/g BW (im) of synthetic adrenocorticotropic hormone (ACTH) significantly increased plasma B levels in cane toads. Changes in size area of the cortical cells were positively associated with total levels of B after ACTH administration. We also found differences in adrenal activity between populations. This was assessed by a DEX-ACTH test. The animals captured from the field and maintained in captivity for one year at the animal house (AH) present the highest levels of total and free B after ACTH administration. We also found that animals from the front line of dispersion in Western Australia (WA) present the weakest adrenal response to a DEX-ACTH test. The animals categorized as long established in Queensland Australia (QL), and native in Mexico (MX), do not shown a marked difference in the HPA activity. Finally we found that in response to ACTH administration, females reach significantly higher levels of plasma B than males. For the first time the adrenocortical response in cane toads exposed to different experimental procedures, as well as from different populations was assessed systematically. PMID:26877241

  12. Ion transport by mitochondria-rich cells in toad skin

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Ussing, H H; Spring, K R

    1987-01-01

    The optical sectioning video imaging technique was used for measurements of the volume of mitochondria-rich (m.r.) cells of the isolated epithelium of toad skin. Under short-circuit conditions, cell volume decreased by about 14% in response to bilateral exposure to Cl-free (gluconate substitution......) solutions, apical exposure to a sodium-free solution, or to amiloride. Serosal exposure to ouabain resulted in a large increase in volume, which could be prevented either by the simultaneous application of amiloride in the apical solution or by the exposure of the epithelium to bilateral Cl-free solutions...

  13. Cane toads lack physiological enhancements for dispersal at the invasive front in Northern Australia

    Directory of Open Access Journals (Sweden)

    Christopher R. Tracy

    2011-11-01

    Many invasive species have evolved behavioural and morphological characteristics that facilitate their dispersal into new areas, but it is unclear how selection on this level of the phenotype filters through to the underlying physiology. Cane toads have been dispersing westward across northern tropical Australia for more than 70 years. Previous studies of cane toads at the invasive front have identified several behavioural, morphological and locomotory characteristics that have evolved to facilitate dispersal of toads. We assessed a range of physiological characteristics associated with locomotory abilities in toads from the long-established, east coast of Australia, from the invasive front, and from a site in between these locations. We measured time to exhaustion and respiratory gases of toads exercising on a treadmill, time to recovery from exhaustion, blood properties (lactate, haematocrit, haemoglobin, red blood cell count, blood cell volume, and muscle properties associated with locomotion (activities of the enzymes citrate synthase and lactate dehydrogenase, and pH buffering capacity. None of the measured physiological parameters supported the hypothesis that toads from the invasive front possess physiological adaptations that facilitate dispersal compared to toads from areas colonised in the past. The strongest difference among the three groups of toads, time to exhaustion, showed exactly the opposite trend; toads from the long-established populations in the east coast had the longest time to exhaustion. Successful colonisers can employ many characteristics to facilitate their dispersal, so the extent to which behaviour, morphology and physiology co-evolve remains an interesting question. However, in the present case at least, behavioural adaptations do not appear to have altered the organism's underlying physiology.

  14. Argentinian pistachio oil and flour: a potential novel approach of pistachio nut utilization.

    Science.gov (United States)

    Martínez, Marcela Lilian; Fabani, María Paula; Baroni, María Verónica; Huaman, Rocío Nahime Magrini; Ighani, Marcelo; Maestri, Damián M; Wunderlin, Daniel; Tapia, Alejandro; Feresin, Gabriela Egly

    2016-05-01

    In order to searching a potential novel approach to pistachio utilization, the chemical and nutritional quality of oil and flour from natural, roasted, and salted roasted pistachios from Argentinian cultivars were evaluated. The pistachio oil has high contents of oleic and linoleic acid (53.5 - 55.3, 29 - 31.4 relative abundance, respectively), tocopherols (896 - 916 μg/g oil), carotenoids (48 - 56 μg/g oil) and chlorophylls (41 - 70 μg/g oil), being a good source for commercial edible oil production. The processing conditions did not affect significantly the fatty acid and minor composition of pistachio oil samples. The content of total phenolic (TP) and flavonoids (FL) was not significantly modified by the roasting process, whereas free radical scavenging (DPPH radical) and antioxidant power decreased in a 20% approximately. Furthermore, salted roasted pistachio flour (SRPF) showed a significant decrease in TP and FL content in comparison to others samples. The phenolic profile of pistachio flours evaluated by LC-ESI-QTOF-MS. The major compounds identified were (+)-catechin (38 - 65.6 μg/g PF d.w.), gallic acid (23 - 36 μg/g PF d.w.) and cyanidin-3-O-galactoside (21 - 23 μg/g PF d.w.). The treatments effects on the phenolics constituents of pistachio flour. Roasting caused a significant reduction of some phenolics, gallic acid and (+)- catechin, and increased others, naringenin and luteolin. Salting and roasting of pistachio increased garlic acid and naringenin content. PMID:27407192

  15. The identity of the South African toad Sclerophrys capensis Tschudi, 1838 (Amphibia, Anura).

    Science.gov (United States)

    Ohler, Annemarie; Dubois, Alain

    2016-01-01

    The toad species Sclerophrys capensis Tschudi, 1838 was erected for a single specimen from South Africa which has never been properly studied and allocated to a known species. A morphometrical and morphological analysis of this specimen and its comparison with 75 toad specimens referred to five South African toad species allowed to allocate this specimen to the species currently known as Amietophrynus rangeri. In consequence, the nomen Sclerophrys must replace Amietophrynus as the valid nomen of the genus, and capensis as the valid nomen of the species. This work stresses the usefulness of natural history collections for solving taxonomic and nomenclatural problems. PMID:26788431

  16. Sensory feedback and coordinating asymmetrical landing in toads.

    Science.gov (United States)

    Cox, S M; Gillis, Gary B

    2016-06-01

    Coordinated landing requires anticipating the timing and magnitude of impact, which in turn requires sensory input. To better understand how cane toads, well known for coordinated landing, prioritize visual versus vestibular feedback during hopping, we recorded forelimb joint angle patterns and electromyographic data from five animals hopping under two conditions that were designed to force animals to land with one forelimb well before the other. In one condition, landing asymmetry was due to mid-air rolling, created by an unstable takeoff surface. In this condition, visual, vestibular and proprioceptive information could be used to predict asymmetric landing. In the other, animals took off normally, but landed asymmetrically because of a sloped landing surface. In this condition, sensory feedback provided conflicting information, and only visual feedback could appropriately predict the asymmetrical landing. During the roll treatment, when all sensory feedback could be used to predict an asymmetrical landing, pre-landing forelimb muscle activity and movement began earlier in the limb that landed first. However, no such asymmetries in forelimb preparation were apparent during hops onto sloped landings when only visual information could be used to predict landing asymmetry. These data suggest that toads prioritize vestibular or proprioceptive information over visual feedback to coordinate landing. PMID:27247440

  17. A challenge of regional integration: the Southern Argentinian pipeline enlargement; Desafio de integracao regional: ampliacao do gasoduto Sul-Argentino

    Energy Technology Data Exchange (ETDEWEB)

    Sardi, Oscar; Sosa, Damian [Transportadora de Gas del Sur S.A., Buenos Aires (Argentina); Duarte Filho, Arno [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2005-07-01

    The enlargement of the pipelines of Southern Argentina comprised the construction of around 500 km of 30' and 36' loops in the first semester of 2005 and presented many peculiarities. It has been the first enlargement of the argentinian pipeline system since the country's default statement, in 2001, and it has been financed and built by a bi national Brazilian-Argentinian consortium. It has also been the first time that a governmental trusteeship has been used in such an enterprise in Argentina to guarantee the necessary funds. The increasing demand of natural gas to industries and power generation plants brought about by Argentina's recent growth has stated the sense of urgency: the construction must be on duty in June 2005, ready to increase de flow of gas to the Provincia de Buenos Aires and Great Buenos Aires regions. This has represented also a technical challenge, due to the small time to built the loops, the geographical distribution of the construction, which extends from Patagonia to the Great Buenos Aires region and the meteorological conditions of the period of the construction. The article describes the negotiations done to assemble the construction's financial and managerial frameworks, the building and the solutions found to face the challenge and to meet the deadline. (author)

  18. Towed Optical Assessment Device (TOAD) Data to Support Benthic Habitat Mapping since 2001

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Optical validation data were collected using a Tethered Optical Assessment Device (TOAD), an underwater sled equipped with an underwater digital video camera and...

  19. Molecular characterization of MHC class II in the Australian invasive cane toad reveals multiple splice variants.

    Science.gov (United States)

    Lillie, Mette; Cui, Jian; Shine, Richard; Belov, Katherine

    2016-07-01

    The cane toad has gained notoriety for its invasion across the Australian landscape, with significant impacts on the native Australian fauna. The invasion has accelerated over time, with invading cane toads adapted for highly dispersive traits. This, however, has come at the cost of the immune system, with lower investment in some immune functions. To investigate the cane toad's immunogenetics, we characterized four major histocompatibility complex (MHC) class IIA and three MHC class IIB loci. Preliminary observations suggest very low allelic diversity at all loci. We also observed various splice isoforms. One isoform seen at one class IIA and two class IIB loci was missing exon 2, which is essential to peptide binding and presentation. The other isoform, observed at a class IIA locus, is likely to be a soluble MHC product. These results may suggest a significant role of alternative splicing of MHC loci in the Australian cane toad. PMID:27233954

  20. Vascular aspects of water uptake mechanisms in the toad skin: perfusion, diffusion, confusion

    DEFF Research Database (Denmark)

    Willumsen, Niels; Viborg, Arne L; Hillyard, Stanley D

    2007-01-01

    . Aquaporins 1-3 were characterized by RT-PCR analysis of seat patch skin. AQP 1 was localized in the endothelium of subepidermal capillaries and serves as a pathway for water absorption in series with the apical and basolateral membranes of the epithelium. Dehydrated toads rehydrated more rapidly from dilute...... coupling explains the greater absorption from dilute salt solutions. Rehydration from 10 mM CaCl2 was stimulated above that of DI water by a similar degree as with 50 mM NaCl suggesting the anion might control water permeability of the skin.......Blood cell flow (BCF) in the water absorbing "seat patch" region of toad skin was measured with laser Doppler flow cytometry. BCF of dehydrated toads increased by a factor of 6-8 when water contact was made and declined gradually as toads rehydrated. Water absorption was initially stimulated...

  1. Differences and Similarities among Parotoid Macrogland Secretions in South American Toads: A Preliminary Biochemical Delineation

    OpenAIRE

    Juliana Mozer Sciani; Cláudia Blanes Angeli; Antoniazzi, Marta M.; Carlos Jared; Daniel Carvalho Pimenta

    2013-01-01

    Amphibians are known by cutaneous glands, spread over the skin, containing toxins (proteins, peptides, biogenic amines, steroidal bufadienolides, and alkaloids) used as chemical defense against predators and microbial infection. Toads are characterized by the presence of parotoid macroglands. The common toads have lately been divided into two genera: Bufo (Europe, Asia, and Africa) and Rhinella (South America). Basal Rhaebo genus is exclusively of Central America and Amazon region. Although R...

  2. Evaluation of the international limitations and conditions of the Argentinian nuclear politics

    International Nuclear Information System (INIS)

    state sector. Among the conclusions, from two different points of view, the decisive importance is shown that had in scientific knowledge and own technological capacities to reach the relative success that has characterized to the nuclear sector inside the Argentinian state activities. Either that it is interpreted to the power of the States or of the international community as the capacity to influence in the political behavior of certain countries, or as the capacity to achieve objectives in the international political negotiations, the Argentine Republic shows objective evidences that prove the outlined hypothesis. (author)

  3. Biotic Resistance to an Alien Amphibian: Larval Competition between Japanese Frogs and Invasive Cane Toads

    Science.gov (United States)

    2016-01-01

    Understanding negative effects of native species on introduced taxa may suggest novel ways to control the invasive species by enhancing such effects. Previous studies have reported that the larvae of invasive cane toads (Rhinella marina) are suppressed by competition with the larvae of native anurans in Australia, but not in North America. We conducted laboratory trials to measure the effect of exposure to the larvae of Japanese frogs (Microhyla ornata, Fejervarya sakishimensis, Rhacophorus owstoni) on rates of survival, growth and development of cane toad tadpoles in Ishigaki Island, in southern Japan. Survival rates were not affected by native species, but competition with Dicroglossids and Rhacophorids (but not Microhylids) strongly reduced rates of growth and development in the tadpoles of cane toads. Dicroglossid tadpoles also reduced the body condition to toad tadpoles in addition to effects on SVL and mass. Encouraging populations of native frogs in toad-invaded areas of Japan thus may help to reduce the numbers of invasive cane toads. PMID:27253973

  4. CEPF Western Ghats Special Series: Description of tadpole stages of the Malabar Tree Toad Pedostibes tuberculosis Gunther, 1875 (Anura: Bufonidae

    Directory of Open Access Journals (Sweden)

    K.P. Dinesh

    2014-10-01

    Full Text Available Pedostibes tuberculosus, the Malabar tree toad, was described 137 years ago from the Malabar region (now the coastal parts of Kerala of the Western Ghats. Since the description of this arboreal toad, not much information is available on the natural history, breeding habits and life cycle except for its description, range of distribution and advertisement call details. In the present account, the tadpole stages of this toad from Gosner tadpole Stage 21 to 45 are presented and the phytotelmatic mode of life of this toad has been confirmed by locating the tadpoles within the Ochlandra reed culm.

  5. The All Optical New Universal Gate Using TOAD

    Directory of Open Access Journals (Sweden)

    Goutam Kumar Maity

    2014-06-01

    Full Text Available Since the seventies of the past century the reversible logic has originated as an unconventional form of computing. It is new relatively in the area of extensive applications in quantum computing, low power CMOS, DNA computing, digital signal processing (DSP, nanotechnology, communication, optical computing, computer graphics, bio information, etc .Here we present and configure a new TAND gate in all-optical domain and also in this paper we have explained their principle of operations and used a theoretical model to fulfil this task, finally supporting through numerical simulations. In the field of ultra-fast all-optical signal processing Terahertz Optical Asymmetric Demultiplexer (TOAD, semiconductor optical amplifier (SOA-based, has an important function. The different logical (composing of Boolean function operations can be executed by designed circuits with TAND gate in the domain of universal logic-based information processing.

  6. Determination of pesticide aerial drift and associated effects to the endangered Wyoming toad (Bufo baxteri) at Mortenson and Hutton National Wildlife Refuges and potential reintroduction sites

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The endangered Wyoming toad is confined to Mortenson National Wildlife Refuge (NWR) in southeast Wyoming. Reasons for the decline of the toad are unknown, but it is...

  7. Behavioural thermoregulation of the Andean toad (Bufo spinulosus) at high altitudes.

    Science.gov (United States)

    Sinsch, U

    1989-03-01

    The body temperature of free-ranging Andean toadsBufo spinulosus was measured either directly or radiotelemetrically during two 15-day periods at 3200 m elevation in the Mantaro Valley, Central Perú. All toads attempted to maintain their diurnal sum of body temperature within a narrow range. Consequently thermoregulatory behaviour differed according to cloud cover and precipitation. If the sky was clear, toads emerged from their hiding place and exposed themselves to solar radiation during 3-5 h in the morning. Core temperature increased up to 15° C above the air temperature in shade and reached maximum values of about 32° C. At air temperatures (in sun) exceeding 29° C, toads maintained body temperatures below 32° C by evaporative cooling. Following heliothermic heating during the moring toads retreated to the shade, thereby decreasing body temperature below air temperature. Under overcast sky toads remained exposed during the whole day displaying body temperatures at or slightly above ambient levels. Quantitative models to predict the core temperature of toads under the different weather conditions demonstrated that the substrate temperature was the main energy source accounting for 64.6-77.9% of total variance whereas air temperature was of minor importance (1.5-4.4%). The unexplained variance was probably due to evaporative cooling. The volume of urine stored into the urinary bladder of toads varied diurnally; during basking in the morning hours most bladders contained large volumes of urine, whereas during the afternoon the bladders were mostly empty. The bladder contents probably serve as water reserves during basking when evaporative water loss was high. Toads preferred sites that provided shady hiding places as well as sun-exposed bare soil within a radius of 5 m. However, they frequently changed their centers of activity and moved to other sites in 20-70 m distance after periods of 2-5 days. The helio-and thigmothermic behaviour of the Andean toad

  8. Global change effects on biogeochemical processes of Argentinian estuaries: an overview of vulnerabilities and ecohydrological adaptive outlooks.

    Science.gov (United States)

    Kopprio, Germán A; Biancalana, Florencia; Fricke, Anna; Garzón Cardona, John E; Martínez, Ana; Lara, Rubén J

    2015-02-28

    The aims of this work are to provide an overview of the current stresses of estuaries in Argentina and to propose adaptation strategies from an ecohydrological approach. Several Argentinian estuaries are impacted by pollutants, derived mainly from sewage discharge and agricultural or industrial activities. Anthropogenic impacts are expected to rise with increasing human population. Climate-driven warmer temperature and hydrological changes will alter stratification, residence time, oxygen content, salinity, pollutant distribution, organism physiology and ecology, and nutrient dynamics. Good water quality is essential in enhancing estuarine ecological resilience to disturbances brought on by global change. The preservation, restoration, and creation of wetlands will help to protect the coast from erosion, increase sediment accretion rates, and improve water quality by removing excess nutrients and pollutants. The capacity of hydrologic basin ecosystems to absorb human and natural impacts can be improved through holistic management, which should consider social vulnerability in complex human-natural systems. PMID:25194878

  9. Magnetic orientation of the Common Toad: establishing an arena approach for adult anurans

    Directory of Open Access Journals (Sweden)

    Gollmann Günter

    2011-03-01

    Full Text Available Abstract Background Magnetic orientation is a taxonomically widespread phenomenon in the animal kingdom, but has been little studied in anuran amphibians. We collected Common Toads (Bufo bufo during their migration towards their spawning pond and tested them shortly after displacement for possible magnetic orientation in arena experiments. Animals were tested in two different set-ups, in the geomagnetic field and in a reversed magnetic field. To the best of our knowledge, this is the first study testing orientation of adult anurans with a controlled magnetic field of a known strength and alignment. Results After displacement, toads oriented themselves unimodally under the geomagnetic field, following their former migration direction (d-axis. When the magnetic field was reversed, the distribution of bearings changed from a unimodal to a bimodal pattern, but still along the d-axis. The clustering of bearings was only significant after the toads reached the outer circle, 60.5 cm from their starting point. At a virtual inner circle (diameter 39 cm and at the start of the experiment, orientation of toads did not show any significant pattern. Conclusions The experimental set-up used in our study is suitable to test orientation behaviour of the Common Toad. We speculate that toads had not enough time to relocate their position on an internal map. Hence, they followed their former migration direction. Bimodality in orientation when exposed to the reversed magnetic field could be the result of a cue conflict, between magnetic and possibly celestial cues. For maintaining their migration direction toads use, at least partly, the geomagnetic field as a reference system.

  10. Effects of amphibian chytrid fungus on individual survival probability in wild boreal toads

    Science.gov (United States)

    Pilliod, D.S.; Muths, E.; Scherer, R. D.; Bartelt, P.E.; Corn, P.S.; Hossack, B.R.; Lambert, B.A.; Mccaffery, R.; Gaughan, C.

    2010-01-01

    Chytridiomycosis is linked to the worldwide decline of amphibians, yet little is known about the demographic effects of the disease. We collected capture-recapture data on three populations of boreal toads (Bufo boreas [Bufo = Anaxyrus]) in the Rocky Mountains (U.S.A.). Two of the populations were infected with chytridiomycosis and one was not. We examined the effect of the presence of amphibian chytrid fungus (Batrachochytrium dendrobatidis [Bd]; the agent of chytridiomycosis) on survival probability and population growth rate. Toads that were infected with Bd had lower average annual survival probability than uninfected individuals at sites where Bd was detected, which suggests chytridiomycosis may reduce survival by 31-42% in wild boreal toads. Toads that were negative for Bd at infected sites had survival probabilities comparable to toads at the uninfected site. Evidence that environmental covariates (particularly cold temperatures during the breeding season) influenced toad survival was weak. The number of individuals in diseased populations declined by 5-7%/year over the 6 years of the study, whereas the uninfected population had comparatively stable population growth. Our data suggest that the presence of Bd in these toad populations is not causing rapid population declines. Rather, chytridiomycosis appears to be functioning as a low-level, chronic disease whereby some infected individuals survive but the overall population effects are still negative. Our results show that some amphibian populations may be coexisting with Bd and highlight the importance of quantitative assessments of survival in diseased animal populations. Journal compilation. ?? 2010 Society for Conservation Biology. No claim to original US government works.

  11. Can we control the invasive cane toad using chemicals that have evolved under intraspecific competition?

    Science.gov (United States)

    Clarke, Gregory S; Crossland, Michael R; Shine, Richard

    2016-03-01

    Many invasive species experience intense intraspecific competition, because they are abundant in anthropogenically disturbed habitats where few native species persist. Species-specific competitive mechanisms that evolve in this context may offer novel, highly targeted means to control invasive taxa. We conducted laboratory experiments to evaluate the feasibility of this method of control, based on waterborne cues that are produced by tadpoles of the cane toad (Rhinella marina) to suppress the development of conspecific embryos. Our trials examined the nature and species-specificity of the effect, the robustness of the cue to freezing and storage, and the amounts required to suppress toad embryos. Our results were encouraging. The cue appears to be chemical rather than a biological organism, and may well be species-specific; the four species of native anurans that we tested were not influenced by toad larval cues. The cue retains its effectiveness after being frozen, but not after being dried, or after 7 d in water. It is effective at very low concentrations (the amount produced by three tadpoles within 750 L of water). Overall, the cane toad's suppressor pheromone may offer an effective new way to control invasive toads. PMID:27209788

  12. Dehydration hardly slows hopping toads (Rhinella granulosa) from xeric and mesic environments.

    Science.gov (United States)

    Prates, Ivan; Angilleta, Michael J; Wilson, Robbie S; Niehaus, Amanda C; Navas, Carlos A

    2013-01-01

    The locomotor capacity of amphibians depends strongly on temperature and hydration. Understanding the potential interactions between these variables remains an important challenge because temperature and water availability covary strongly in natural environments. We explored the effects of temperature and hydration on the hopping speeds of Rhinella granulosa, a small toad from the semiarid Caatinga and the Atlantic Rain Forest in Brazil. We asked whether thermal and hydric states interact to determine performance and whether toads from the Caatinga differ from their conspecifics from the Atlantic Forest. Both dehydration and cooling impaired hopping speed, but effects were independent of one another. In comparison to performances of other anurans, the performance of R. granulosa was far less sensitive to dehydration. Consequently, dehydrated members of this species may be able to sustain performance through high body temperatures, which agrees with the exceptional heat tolerance of this species. Surprisingly, toads from both the Caatinga and the Atlantic Forest were relatively insensitive to dehydration. This observation suggests that migration or gene flow between toads from the forest and those from a drier region occurred or that toads from a dry region colonized the forest secondarily. PMID:23799839

  13. Citizenchip and gender on the rural World: The Union of Argentinian Women and the female peasants during the peronism (1943-1955

    Directory of Open Access Journals (Sweden)

    María Eugenia Bordagaray

    2008-04-01

    Full Text Available In this work we try to analyze first which were the interpretations that from Nuestras Mujeres, the Union of Argentinian Women (Unión Argentina de Mujeres magazine, made about the rural women and its problems during the first peronism. Secondly, we will try to explain why the UMA tried to organize the rural woman in its core, and why they have so little success. The analysis of the magazine Nuestras Mujeres.

  14. Contribution to the study of immune hemolysis by toad complement

    Directory of Open Access Journals (Sweden)

    Marisa Gennari

    1982-09-01

    Full Text Available EA (sheep erythrocytes carrying rabbit antibody are lysed by toad complement under optimal conditions which include a low concentration of cells (1.54 x 10*8/ml, a low temperature of incubation (30°C and the same amounts of Ca++ and Mg++ as required for the titration of guinea-pig complement. Kinetic studies of the role of cations mentioned above in immune lysis by toad C have disclosed a fundamental difference as compared to guinea-pig C. In a limited complement system, the lysis by amphibian C is completely blocked by EDTA, even when the chelating agent is added as late as 15 minutes after zero-time. Inhibition by EGTA is only partial and the findings suggest that Mg++ is required not only at the beginning, but also at late stages of the lytic process. It has been speculated that the activation of amphibian complement proceeds mainly by the alternative pathway.EA (eritrócitos de carneiro, sensibilizados com anticorpos de coelho são lisados por complemento de sapo em condições ótimas, que consistem no uso de uma baixa concentração de células (1.54 x 10*8/ml, incubação a baixa temperatura (30°C e as mesmas quantidades de Ca++ e de Mg++, requeridas para a titulação da atividade hemolítica do complemento de cobaia. Estudos cinéticos do efeito dos cátions mencionados acima na imune-lise produzida pelo complemento de sapo revelam uma diferença fundamental com relação ao complemento de cobaía. Num sistema limitado pela quantidade de complemento, a lise pelo C de anfíbio é totalmente bloqueada por EDTA, mesmo quando a adição do agente quelante é feita após 15 minutos, ao passo que com EGTA o bloqueio é apenas parcial. Os achados experimentais sugerem que Mg++ seja requerido não apenas no estágio inicial, mas também em estágios tardios do processo lítico e permitem especular que a ativação do complemento de anfíbio se processa predominantemente pela via alternativa.

  15. Mapping the Relative Probability of Common Toad Occurrence in Terrestrial Lowland Farm Habitat in the United Kingdom.

    Directory of Open Access Journals (Sweden)

    Rosie D Salazar

    Full Text Available The common toad (Bufo bufo is of increasing conservation concern in the United Kingdom (UK due to dramatic population declines occurring in the past century. Many of these population declines coincided with reductions in both terrestrial and aquatic habitat availability and quality and have been primarily attributed to the effect of agricultural land conversion (of natural and semi-natural habitats to arable and pasture fields and pond drainage. However, there is little evidence available to link habitat availability with common toad population declines, especially when examined at a broad landscape scale. Assessing such patterns of population declines at the landscape scale, for instance, require an understanding of how this species uses terrestrial habitat.We intensively studied the terrestrial resource selection of a large population of common toads in Oxfordshire, England, UK. Adult common toads were fitted with passive integrated transponder (PIT tags to allow detection in the terrestrial environment using a portable PIT antenna once toads left the pond and before going into hibernation (April/May-October 2012 and 2013. We developed a population-level resource selection function (RSF to assess the relative probability of toad occurrence in the terrestrial environment by collecting location data for 90 recaptured toads.The predicted relative probability of toad occurrence for this population was greatest in wooded habitat near to water bodies; relative probability of occurrence declined dramatically > 50 m from these habitats. Toads also tended to select habitat near to their breeding pond and toad occurrence was negatively related to urban environments.

  16. Optimizing the performance of TOAD by changing the wavelength and power of control pulse

    Institute of Scientific and Technical Information of China (English)

    Liangsheng Wen(温亮生); Peng Zuo(左鹏); Jian Wu(伍剑); Jintong Lin(林金桐)

    2003-01-01

    The performance of terahertz optical asymmetric demultiplexer (TOAD) has been studied by modelling the semiconductor optical amplifier (SOA) in which the intraband effects had been taken into account.Numerical results are coincident with the experiment results. We interpret why there are three peaks in the switching window, which has never been reported before. In addition, we put forward the definition of the flatness of the switching window of TOAD for the first time By analysing the different phase of clockwise and counter clockwise signal pulse changed by SOA, appropriate peak power of control pulse and wavelength of signal and control pulse have been calculated in order to obtain large output power and flat switching window of TOAD.

  17. Anticipatory motor patterns limit muscle stretch during landing in toads.

    Science.gov (United States)

    Azizi, Emanuel; Abbott, Emily M

    2013-02-23

    To safely land after a jump or hop, muscles must be actively stretched to dissipate mechanical energy. Muscles that dissipate energy can be damaged if stretched to long lengths. The likelihood of damage may be mitigated by the nervous system, if anticipatory activation of muscles prior to impact alters the muscle's operating length. Anticipatory motor recruitment is well established in landing studies and motor patterns have been shown to be modulated based on the perceived magnitude of the impact. In this study, we examine whether motor recruitment in anticipation of landing can serve a protective function by limiting maximum muscle length during a landing event. We use the anconeus muscle of toads, a landing muscle whose recruitment is modulated in anticipation of landing. We combine in vivo measurements of muscle length during landing with in vitro characterization of the force-length curve to determine the muscle's operating length. We show that muscle shortening prior to impact increases with increasing hop distance. This initial increase in muscle shortening functions to accommodate the larger stretches required when landing after long hops. These predictive motor strategies may function to reduce stretch-induced muscle damage by constraining maximum muscle length, despite variation in the magnitude of impact. PMID:23256184

  18. Effect of stretch on passive transport in toad urinary bladder.

    Science.gov (United States)

    Lief, P D; Mutz, B F; Bank, N

    1976-06-01

    In order to gain further information about the effect of stretch on the urinary bladder of the toad, transepithelial movement of radioactive sucrose, chloride, and urea was measured across bladder sacs during acute changes in the internal volume. Short-circuit current (SCC) and total tissue conductance (Kt) were also measured in each experiment. It was found that sudden large increases or smaller graded increases in volume resulted in a consistent fall in the tracer permeability (P*) of all three isotopes. However, this fall was due entirely to the larger area term in the calculation of P* rather than any real change in isotope movement. When total diffusion (TD) of each isotope was calculated by a method that eliminated the changes in surface area, it was apparent that stretch produced no significant effects on the transepithelial movement of any of these three molecules. Large stretch also resulted in parallel increases in SCC and Kt in most bladders. We conclude from these observations that the intercellular pathway for sucrose and chloride and the transcellular pathway for urea are unaltered by degrees of stretch that enhance SCC and sodium transport. By inference, the observed increases in Kt appear to represent changes in specific active pathway conductance (Ka), and may relate importantly to the changes in sodium transport. PMID:820207

  19. Multiple paternity in a viviparous toad with internal fertilisation

    Science.gov (United States)

    Sandberger-Loua, Laura; Feldhaar, Heike; Jehle, Robert; Rödel, Mark-Oliver

    2016-08-01

    Anurans are renowned for a high diversity of reproductive modes, but less than 1 % of species exhibit internal fertilisation followed by viviparity. In the live-bearing West African Nimba toad ( Nimbaphrynoides occidentalis), females produce yolk-poor eggs and internally nourish their young after fertilisation. Birth of fully developed juveniles takes place after 9 months. In the present study, we used genetic markers (eight microsatellite loci) to assign the paternity of litters of 12 females comprising on average 9.7 juveniles. In 9 out of 12 families (75 %), a single sire was sufficient; in three families (25 %), more than one sire was necessary to explain the observed genotypes in each family. These findings are backed up with field observations of male resource defence (underground cavities in which mating takes place) as well as coercive mating attempts, suggesting that the observed moderate level of multiple paternity in a species without distinct sperm storage organs is governed by a balance of female mate choice and male reproductive strategies.

  20. An anionic antimicrobial peptide from toad Bombina maxima.

    Science.gov (United States)

    Lai, Ren; Liu, Hen; Hui Lee, Wen; Zhang, Yun

    2002-07-26

    Amphibian skin is a rich resource of antimicrobial peptides like maximins and maximins H from toad Bombina maxima. A novel cDNA clone encoding a precursor protein that comprises maximin 3 and a novel peptide, named maximin H5, was isolated from a skin cDNA library of B. maxima. The predicted primary structure of maximin H5 is ILGPVLGLVSDTLDDVLGIL-NH2. Containing three aspartate residues and no basic amino acid residues, maximin H5 is characterized by an anionic property. Different from cationic maximin H peptides, only Gram-positive strain Staphylococcus aureus was sensitive to maximin H5, while the other bacterial and fungal strains tested were resistant to it. The presence of metal ions, like Zn2+ and Mg2+, did not increase its antimicrobial potency. Maximin H5 represents the first example of potential anionic antimicrobial peptides from amphibians. The results provide the first evidence that, together with cationic antimicrobial peptides, anionic antimicrobial peptides may also exist naturally as part of the innate defense system. PMID:12127963

  1. Nux Vomica 200 CH reduced acute hypnotic effect of alcohol in young toads

    OpenAIRE

    Nirmal Sukul; Arniban Sukul; Indrani Chakraborty

    2012-01-01

    Potentized Nux Vomica has been reported to produce antialcoholic effect in mice, rats and toads. The effect relates to consumption of alcohol and alcohol-induced loss of righting reflex (RR). RR’s maintain normal erect posture of an animal and are centrally controlled in the midbrain. In the present study young toads, Duttaphrynus melanostictus were first treated with Nux vomica 200 CH and then partially immersed in 209 mM ethanol solution in such a way that their head remained above t...

  2. New regional record and notes on historical specimens of Gunther Toad Duttaphrynus hololius with comments on other southeastern Indian congeners

    Directory of Open Access Journals (Sweden)

    B. Srinivasulu

    2013-09-01

    Full Text Available We report on the finding of the Günther Toad Duttaphrynus hololius from Visakhapatnam and discuss aspects of its distribution based on our species distribution modeling. We also provide data on historically collected specimens and refine its intra-specific variation, provide an up-to-date chresonymy and comment on the validity of earlier reported diagnosis. Lastly, we remark on some misidentification-mediated dubious southern Indian records of another, related congener, the Marbled Toad D. stomaticus and correct some misallocations by referring them to another syntopic congener, the Dwarf Toad D. scaber.

  3. Effect of parathyroid hormone on transport by toad and turtle bladder

    International Nuclear Information System (INIS)

    The authors recently demonstrated that parathyroid hormone (PTH) inhibited both vasopressin- and cyclic AMP-stimulated water transport in the toad bladder. This was associated with an increase in calcium uptake by isolated epithelial cells. They postulated that PTH exerts its action on H2O transport by directly stimulating calcium uptake. The current study was designed to compare the effects of PTH and the calcium ionophore, A23187, on H2O and Na transport and Hμ secretion in toad and turtle bladders. In toad bladder, PTH and A23187 decreased arginine vasopressin (AVP)-stimulated H2O flow and short-circuit current (SCC) after 60 min serosal incubation. In turtle bladder A23187 decreased SCC to 79.3 +/- 3.6% of base line (P + secretion in turtle bladders. Both PTH and A23187 increased 45Ca uptake in toad bladder epithelial cells; only A23187 increased 45Ca uptake in the turtle bladder. The different action of PTH in these two membranes, compared with that of the calcium ionophore, illustrates the selectivity of PTH on membrane transport. PTH increases calcium uptake and decreases transport only in a hormone-sensitive epithelium, whereas the ionophore works in virtually all living membranes. The mode of action of these two agents to increase calcium uptake is, therefore likely different

  4. ACTION OF PROGESTERONE ON THE DEPOLARIZATION OF THE MEMBRANE POTENTIAL IN TOAD OOCYTES INDUCED BY LEUCINE

    Institute of Scientific and Technical Information of China (English)

    WANGYu-Feng

    1989-01-01

    The depolarization of the membrane potential in toad oocytes induced by leucine was found in our previous experiment. In this paper, a possible action or progesterone in the process was further investigated. After oocytes had been incubated for 16 to 24 hours with

  5. Corticosterone-immune interactions during captive stress in invading Australian cane toads (Rhinella marina).

    Science.gov (United States)

    Graham, Sean P; Kelehear, Crystal; Brown, Gregory P; Shine, Richard

    2012-07-01

    Vertebrates cope with physiological challenges using two major mechanisms: the immune system and the hypothalamic pituitary-adrenal axis (e.g., the glucocorticoid stress response). Because the two systems are tightly integrated, we need simultaneous studies of both systems, in a range of species, to understand how vertebrates respond to novel challenges. To clarify how glucocorticoids modulate the amphibian immune system, we measured three immune parameters and plasma corticosterone (CORT), before and after inflicting a stressor (capture and captive confinement) on introduced cane toads (Rhinella marina) near their invasion front in Australia. Stress increased CORT levels, decreased complement lysis capacity, increased leukocyte oxidative burst, and did not change heterologous erythrocyte agglutination. The strength of the CORT response was positively correlated with leukocyte oxidative burst, and morphological features associated with invasiveness in cane toads (relative leg length) were correlated with stress responsiveness. No immune parameter that we measured was affected by a toad's infection by a parasitic nematode (Rhabdias pseudosphaerocephala), but the CORT response was muted in infected versus uninfected toads. These results illustrate the complex immune-stress interactions in wild populations of a non-traditional model vertebrate species, and describe immune adaptations of an important invasive species. PMID:22713726

  6. Tetrodotoxin and its analogues in extracts from the toad Atelopus oxyrhynchus (family: Bufonidae).

    Science.gov (United States)

    Yotsu-Yamashita, M; Mebs, D; Yasumoto, T

    1992-11-01

    Tetrodotoxin and its analogues, 4-epitetrodotoxin and 4,9-anhydrotetrodotoxin, were detected in the toad Atelopus oxyrhynchus by HPLC analysis. The toxin and its analogues were still present in a specimen which lived 3.5 years in captivity. PMID:1336632

  7. Diagnostic histological findings in Yosemite toads (Bufo canorus) from die-off in the 1970s

    Science.gov (United States)

    Green, D.E.; Sherman, C.K.

    2001-01-01

    Twelve adult and 25 larval Yosemite toad (Bufo canorus) specimens from the eastern Sierra Nevada of California were examined histologically for evidence of infectious, toxicological, and degenerative diseases. The preserved toads were selected from 21 that had been salvaged or collected during a die-off in 1976-1979 that immediately preceded a population decline. Causes of death of four toads were determined histologically; clinical signs and field observations suggested causes of death of three more. Four toads died of infectious diseases, including chytridiomycosis of the skin (N = 1), bacillary septicemia (N = 2), and combined chytridiomycosis and bacterial septicemia (N = 1). Infections by a funguslike organism (Dermosporidium penneri), renal myxozoa (Leptotheca ohlmacheri), larval Rhabdias, various gastrointestinal nematodes, urinary bladder flukes, and lung flukes were detected in five specimens. No evidence of degenerative diseases, virus infections, or intoxications was found. The variety of lethal diseases and our inability to determine the causes of death of five specimens suggests that one or more histologically undetectable diseases or intoxications may have also contributed to the deaths and population decline.

  8. DIET OF THE SOUTHERN TOAD (BUFO TERRESTRIS) FROM THE SOUTHERN EVERGLADES

    Science.gov (United States)

    We examined the diet of a February-May sample of the southern toad (Bufo terrestris) from the Everglades National Park. Above the familial level, 13 taxa were consumed, but ants (Hymenoptera) and beetles (Coleoptera) were consumed most by, and in the greatest number of sto...

  9. Determination of impacts on the endangered Wyoming toad (Bufo baxteri) at Mortenson National Wildlife Refuge from ammonium nitrate concentrations

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The endangered Wyoming toad (Bufo baxteri) is found only as a reintroduced population at Mortenson NWR in the Laramie Plains of southeast Wyoming. Reasons for the...

  10. Sodium recirculation and isotonic transport in toad small intestine.

    Science.gov (United States)

    Nedergaard, S; Larsen, E H; Ussing, H H

    1999-04-01

    Isolated small intestine of toad (Bufo bufo) was mounted on glass tubes for perfusion studies with oxygenated amphibian Ringer's solution containing glucose and acetate. Under open-circuit conditions (Vt = -3.9 +/- 1.8 mV, N = 14) the preparation generated a net influx of 134Cs+. The time course of unidirectional 134Cs+-fluxes was mono-exponential with similar rate constants for influx and outflux when measured in the same preparation. The flux-ratio was time invariant from the beginning of appearance of the tracers to steady state was achieved. Thus, just a single pathway, the paracellular pathway, is available for transepithelial transport of Cs+. From the ratio of unidirectional Cs+-fluxes the paracellular force was calculated to be, 18.2 +/- 1.5 mV (N = 6), which is directed against the small transepithelial potential difference. The paracellular netflux of cesium ions, therefore, is caused by solvent drag. The flux of 134Cs+ entering and trapped by the cells was of a magnitude similar to that passing the paracellular route. Therefore, independent of the convective flux of 134Cs+, every second 134Cs+ ion flowing into the lateral space was pumped into the cells rather than proceeding, via the low resistance pathway, to the serosal bath. It is thus indicated that the paracellular convective flow of 134Cs+ is driven by lateral Na+/K+-pumps. Transepithelial unidirectional 42K+ fluxes did not reach steady state within an observation period of 70 min, indicating that components of the fluxes in both directions pass the large cellular pool of potassium ions. The ratio of unidirectional 24Na+ fluxes was time-variant and declined from an initial value of 3.66 +/- 0.34 to a significantly smaller steady-state value of 2.57 +/- 0.26 (P water-filled pores. With a new set of equations, the fraction of the sodium flux passing the basement membrane barrier of the lateral space that is recirculated through the cellular compartment is estimated. This fraction was, on average, 0

  11. Spatial and temporal ecology of oak toads (Bufo quercicus) on a Florida landscape.

    Energy Technology Data Exchange (ETDEWEB)

    Greenberg, Cathryn, H.; Tanner, George, W.

    2005-12-01

    ABSTRACT: We used data from 10 years of continuous, concurrent monitoring of oak toads at eight isolated, ephemeral ponds in Florida longleaf pine-wiregrass uplands to address: (1) did weather variables affect movement patterns of oak toads?; (2) did pond hydrology and the condition of surrounding uplands affect pond selection by adults or juvenile recruitment?; (3) were population trends evident?; and (4) did a classical metapopulation model best represent their population ecology? Of 4076 oak toads captured, 92.2% were adults. Substantial (n _ 30 exiting juveniles) recruitment occurred only three times (once each at three ponds during two years). Males outnumbered females (average for all years 2.3:1). Most captures occurred during May–September. Adult captures during June–August increased with heavier rainfall but were not influenced by the durations of preceding dry periods. Movement patterns of metamorphs suggested that oak toads emigrated when moisture conditions become favorable. Pond use by adults was correlated with maximum change in pond depth (May–September). Juvenile recruitment was negatively correlated with minimum pond depth and the number of weeks since a pond was last dry, and positively correlated with the maximum number of weeks a pond held water continuously. The number of breeding adults and juvenile recruitment were highest at ponds within the hardwood-invaded upland matrix. The direction of most immigrations and emigrations was nonrandom, but movement occurred from all directions, and the mean direction of pond entry and exit did not always correspond. A total of 21.1% of individuals was recaptured; 13.3% of first captures were recaptured during the same year, and 7.7% during a subsequent year. Only 1.9% of captured oak toads moved among ponds, mostly within a distance of 132 m. We did not detect adult population trends over the 10- yr studied. Presence or absence at ponds in any given year was a poor indicator of overall use. We saw

  12. Depth perception in frogs and toads a study in neural computing

    CERN Document Server

    House, Donald

    1989-01-01

    Depth Perception in Frogs and Toads provides a comprehensive exploration of the phenomenon of depth perception in frogs and toads, as seen from a neuro-computational point of view. Perhaps the most important feature of the book is the development and presentation of two neurally realizable depth perception algorithms that utilize both monocular and binocular depth cues in a cooperative fashion. One of these algorithms is specialized for computation of depth maps for navigation, and the other for the selection and localization of a single prey for prey catching. The book is also unique in that it thoroughly reviews the known neuroanatomical, neurophysiological and behavioral data, and then synthesizes, organizes and interprets that information to explain a complex sensory-motor task. The book will be of special interest to that segment of the neural computing community interested in understanding natural neurocomputational structures, particularly to those working in perception and sensory-motor coordination. ...

  13. Axial gradients of rhodopsin in light-exposed retinal rods of the toad

    OpenAIRE

    1990-01-01

    Exposure of an intact vertebrate eye to light bleaches the rhodopsin in the photoreceptor outer segments in spatially nonuniform patterns. Some axial bleaching patterns produced in toad rods were determined using microspectrophotometric techniques. More rhodopsin was bleached at the base of the outer segment than at the distal tip. The shape of the bleaching gradient varied with the extent of bleach and with the spectral content of the illuminant. Monochromatic light at the lambda max of the ...

  14. Elevated temperature clears chytrid fungus infections from tadpoles of the midwife toad, Alytes obstetricans

    OpenAIRE

    Geiger, C C; Küpfer, E; Schär, S; Wolf, S.; Schmidt, B R

    2011-01-01

    The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) is sensitive to high temperature. Hence, exposing amphibians to high temperature may be a method to clear Bd infection. However, the effect of exposure to elevated temperature has never been tested in larval stages or temperate species.We experimentally exposed tadpoles of the toad Alytes obstetricans to low, medium and high temperatures and found that most, but not all, tadpoles lost the infection when exposed to temperature...

  15. Chytridiomycosis related mortality in a midwife toad (Alytes obstetricans) in Belgium

    OpenAIRE

    Pasmans, Frank; Muijsers, Mariska; Maes, Sofie; Van Rooij, Pascale; Brutyn, Melanie; Ducatelle, Richard; Haesebrouck, Freddy; Martel, An

    2010-01-01

    Chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis, contributes to amphibian declines worldwide. Recently, the fungus has shown to be widely distributed in Belgium and the Netherlands, although no clinical cases of the disease have been diagnosed yet. This case report describes the first case of mortality due to chytridiomycosis in Belgium in a wild population of midwife toads (Alytes obstetricans). The presence of clinical chytridiomycosis, combined with the relatively hig...

  16. Deep genetic structure and ecological divergence in a widespread human commensal toad

    OpenAIRE

    Wogan, GOU; Stuart, BL; Iskandar, DT; McGuire, JA

    2016-01-01

    © 2016 The Author(s) Published by the Royal Society. All rights reserved. The Asian common toad (Duttaphrynus melanostictus) is a human commensal species that occupies a wide variety of habitats across tropical Southeast Asia. We test the hypothesis that genetic variation in D. melanostictus is weakly associated with geography owing to natural and human-mediated dispersal facilitated by its commensal nature. Phylogenetic and population genetic analyses of mitochondrial and nuclear DNA sequenc...

  17. The action of local anesthetics on myelin structure and nerve conduction in toad sciatic nerve.

    OpenAIRE

    Mateu, L; Morán, O; Padrón, R; Borgo, M; Vonasek, E; Márquez, G; Luzzati, V.

    1997-01-01

    X-ray scattering and electrophysiological experiments were performed on toad sciatic nerves in the presence of local anesthetics. In vitro experiments were performed on dissected nerves superfused with Ringer's solutions containing procaine, lidocaine, tetracaine, or dibucaine. In vivo experiments were performed on nerves dissected from animals anesthesized by targeted injections of tetracaine-containing solutions. In all cases the anesthetics were found to have the same effects on the x-ray ...

  18. Phonotaxis to advertisement calls by midwife toads (Alytes muletensis) is not necessarily related to mating

    OpenAIRE

    Lea, Jerry; Dyson, Mandy; Halliday, Timothy

    2002-01-01

    Previous studies with the Mallorcan midwife toad (Alytes muletensis) found that gravid females show inconsistent phonotactic preferences for male calls unless they are highly motivated to mate; and, non-gravid females will occasionally show phonotaxis to male advertisement calls. These results suggest that sometimes phonotaxis may not be related to seeking a mating partner. In this article we report on experiments that give further support to a non-mating function of phonotaxis in this specie...

  19. Evolution of Rapid Development in Spadefoot Toads Is Unrelated to Arid Environments

    OpenAIRE

    Zeng, Ce; Gómez-Mestre, Iván; Wiens, John J.

    2014-01-01

    The extent to which species' life histories evolve to match climatic conditions is a critical question in evolutionary biology and ecology and as human activities rapidly modify global climate. GIS-based climatic data offer new opportunities to rigorously test this question. Superficially, the spadefoot toads of North America (Scaphiopodidae) seem to offer a classic example of adaptive life-history evolution: some species occur in extremely dry deserts and have evolved the shortest aquatic la...

  20. About a Snail, a Toad, and Rodents: Animal Models for Adaptation Research

    OpenAIRE

    Roubos, Eric W.; Bruce G. Jenks; Lu eXu; Miyuki eKuribara; Wim J. J. M. Scheenen; Tamas eKozicz

    2010-01-01

    Neural adaptation mechanisms have many similarities throughout the animal kingdom, enabling to study fundamentals of human adaptation in selected animal models with experimental approaches that are impossible to apply in man. This will be illustrated by reviewing research on three of such animal models, viz. (1) the egg-laying behavior of a snail, Lymnaea stagnalis: how one neuron type controls behavior, (2) adaptation to the ambient light condition by a toad, Xenopus laevis: how a neuroendoc...

  1. First report on toxins in the Panamanian toads Atelopus limosus, A. glyphus and A. certus.

    Science.gov (United States)

    Yotsu-Yamashita, Mari; Tateki, Eiko

    2010-01-01

    Major toxins from skin extracts of 18 specimens of six Atelopus toad species collected in Panama were analyzed. Chiriquitoxin was identified using (1)H NMR in A. limosus and A. glyphus for the first time. Zetekitoxin in A. zeteki and tetrodotoxin in A. varius, A. chiriquiensis and A. zeteki were identified again. Furthermore, A. certus was suggested to contain a water-soluble toxin other than tetrodotoxin. PMID:19596024

  2. Rapid differentiation of sexual signals in invasive toads: call variation among populations

    OpenAIRE

    Kiyomi Yasumiba; Duffy, Richard L.; Parsons, Scott A.; Ross A Alford; Lin Schwarzkopf

    2016-01-01

    Advertisement calls tend to differ among populations, based on morphological and environmental factors, or simply geographic distance, in many taxa. Invasive cane toads (Rhinella marina) were introduced to Australia in 1935 and their distribution has expanded at increasing rates over time. Rapid evolution occurred in morphological and behavioural characters that accelerate dispersal, but the effects of rapid expansion on sexual signals have not been examined. We collected advertisement calls ...

  3. Effects of weather on survival in populations of boreal toads in Colorado

    Science.gov (United States)

    Scherer, R. D.; Muths, E.; Lambert, B.A.

    2008-01-01

    Understanding the relationships between animal population demography and the abiotic and biotic elements of the environments in which they live is a central objective in population ecology. For example, correlations between weather variables and the probability of survival in populations of temperate zone amphibians may be broadly applicable to several species if such correlations can be validated for multiple situations. This study focuses on the probability of survival and evaluates hypotheses based on six weather variables in three populations of Boreal Toads (Bufo boreas) from central Colorado over eight years. In addition to suggesting a relationship between some weather variables and survival probability in Boreal Toad populations, this study uses robust methods and highlights the need for demographic estimates that are precise and have minimal bias. Capture-recapture methods were used to collect the data, and the Cormack-Jolly-Seber model in program MARK was used for analysis. The top models included minimum daily winter air temperature, and the sum of the model weights for these models was 0.956. Weaker support was found for the importance of snow depth and the amount of environmental moisture in winter in modeling survival probability. Minimum daily winter air temperature was positively correlated with the probability of survival in Boreal Toads at other sites in Colorado and has been identified as an important covariate in studies in other parts of the world. If air temperatures are an important component of survival for Boreal Toads or other amphibians, changes in climate may have profound impacts on populations. Copyright 2008 Society for the Study of Amphibians and Reptiles.

  4. Modeling amphibian energetics, habitat suitability, and movements of western toads, Anaxyrus (=Bufo) boreas, across present and future landscapes

    Science.gov (United States)

    Bartelt, Paul E.; Klaver, Robert W.; Porter, Warren P.

    2010-01-01

    Effective conservation of amphibian populations requires the prediction of how amphibians use and move through a landscape. Amphibians are closely coupled to their physical environment. Thus an approach that uses the physiological attributes of amphibians, together with knowledge of their natural history, should be helpful. We used Niche Mapper™ to model the known movements and habitat use patterns of a population of Western toads (Anaxyrus (=Bufo) boreas) occupying forested habitats in southeastern Idaho. Niche Mapper uses first principles of environmental biophysics to combine features of topography, climate, land cover, and animal features to model microclimates and animal physiology and behavior across landscapes. Niche Mapper reproduced core body temperatures (Tc) and evaporation rates of live toads with average errors of 1.6 ± 0.4 °C and 0.8 ± 0.2 g/h, respectively. For four different habitat types, it reproduced similar mid-summer daily temperature patterns as those measured in the field and calculated evaporation rates (g/h) with an average error rate of 7.2 ± 5.5%. Sensitivity analyses indicate these errors do not significantly affect estimates of food consumption or activity. Using Niche Mapper we predicted the daily habitats used by free-ranging toads; our accuracy for female toads was greater than for male toads (74.2 ± 6.8% and 53.6 ± 15.8%, respectively), reflecting the stronger patterns of habitat selection among females. Using these changing to construct a cost surface, we also reconstructed movement paths that were consistent with field observations. The effect of climate warming on toads depends on the interaction of temperature and atmospheric moisture. If climate change occurs as predicted, results from Niche Mapper suggests that climate warming will increase the physiological cost of landscapes thereby limiting the activity for toads in different habitats.

  5. Hydrosmotic effect of angiotensin II in the toad skin: role of cyclic AMP.

    Science.gov (United States)

    Coviello, A; Brauckmann, E S; de Atenor, M S; Apud, J A; Causarano, J

    1975-01-01

    The mechanism of action of the hydrosmotic response of the isolated skin of the toad Bufo arenarum Hensel to angiotensin II was studied by means of an indirect pharmacological approach. Angiotensin II (2.10(-10) M), vasopressin (2.10(-13) M) and theophylline (10(-4) and 10(-3) M) in subliminal doses produced a significant increase on water permeability when added in different paired combinations. Angiotensin II (2.10(-7) M) and vasopressin (2.10(-8) M) in doses producing significant effects on water permeability increased the response to submaximal doses of epinephrine (10(-6) M) but not to higher doses (10(-5) M). Acid pH (6.4) and prostaglandin E1 (2.10(-7) M) reduced significantly the hydrosmotic response to angiotensin II, but in contrast with the toad bladder, the effect was not completely abolished. Present results support the view that the hydrosmotic effect of angiotensin II in toad skin is mediated by the adenylate cyclase - cyclic AMP system. PMID:189568

  6. The osmotic behaviour of toad skin epithelium (Bufo viridis). an electron microprobe analysis.

    Science.gov (United States)

    Rick, R; Dörge, A; Katz, U; Bauer, R; Thurau, K

    1980-05-01

    The effect of saline adaptation on the intracellular Na, K, Cl, P concentrations and dry weight content of the toad skin epithelium (Bufo viridis) was studied using the technique of electron microprobe analysis. The measurements were performed on isolated abdominal skins either directly after dissection or after additional incubation in Ussing-type chambers. Adaptations of the toads to increasing NaCl concentrations for 7 days resulted in increased blood plasma osmolarity and a parallel increase in the cellular electrolyte, P and dry weight concentrations of the epithelium, the K increase representing the most significant fraction of the intracellular osmolarity increase. No evidence was obtained to show that the nucleus and cytoplasm reacted differently from each other and all living epithelial cell types basically showed the same response. Incubation of the isolated skins under control conditions showed a drastic inhibition of the transepithelial Na transport after adaptation to high salinities. In spite of the large variations in the transport rate almost identical intracellular electrolyte concentrations were observed. In tap water adapted toads the average cellular concentrations were 8.8 mmole/kg wet weight for Na, 109.6 for K, 41.5 for Cl, and 135.3 for P, respectively. Incubation of the skin with Ringer's solution of different osmolarities demonstrated that the epithelial cells are in osmotic equilibrium with the inner bathing solution. The results are consistent with the view that the osmotic adaptation is mainly accomplished by the movement of water. PMID:7191092

  7. Inhibitory bacteria reduce fungi on early life stages of endangered Colorado boreal toads (Anaxyrus boreas).

    Science.gov (United States)

    Kueneman, Jordan G; Woodhams, Douglas C; Van Treuren, Will; Archer, Holly M; Knight, Rob; McKenzie, Valerie J

    2016-04-01

    Increasingly, host-associated microbiota are recognized to mediate pathogen establishment, providing new ecological perspectives on health and disease. Amphibian skin-associated microbiota interact with the fungal pathogen, Batrachochytrium dendrobatidis (Bd), but little is known about microbial turnover during host development and associations with host immune function. We surveyed skin microbiota of Colorado's endangered boreal toads (Anaxyrus boreas), sampling 181 toads across four life stages (tadpoles, metamorphs, subadults and adults). Our goals were to (1) understand variation in microbial community structure among individuals and sites, (2) characterize shifts in communities during development and (3) examine the prevalence and abundance of known Bd-inhibitory bacteria. We used high-throughput 16S and 18S rRNA gene sequencing (Illumina MiSeq) to characterize bacteria and microeukaryotes, respectively. Life stage had the largest effect on the toad skin microbial community, and site and Bd presence also contributed. Proteobacteria dominated tadpole microbial communities, but were later replaced by Actinobacteria. Microeukaryotes on tadpoles were dominated by the classes Alveolata and Stramenopiles, while fungal groups replaced these groups after metamorphosis. Using a novel database of Bd-inhibitory bacteria, we found fewer Bd-inhibitory bacteria in post-metamorphic stages correlated with increased skin fungi, suggesting that bacteria have a strong role in early developmental stages and reduce skin-associated fungi. PMID:26565725

  8. MIGRACIÓN Y MOVILIDAD MAPUCHE A LA PATAGONIA ARGENTINA MAPUCHE MIGRATION AND MOBILITY TO ARGENTINIAN PATAGONIA

    Directory of Open Access Journals (Sweden)

    HANS GUNDERMANN

    2009-07-01

    Full Text Available El artículo presenta antecedentes acerca de la migración y movilidad campesina y mapuche desde las regiones de La Araucanía, Los Ríos y Los Lagos a la Patagonia argentina, especialmente al Neuquén y Río Negro, durante la segunda mitad del siglo XX, como parte de un proceso mucho más amplio de redistribución espacial que incluye el centro de Chile, Magallanes y la Patagonia trasandina. Se describen sus características y los cambios que en ella han tenido lugar, tanto por los vaivenes de las economías y las relaciones entre Chile y Argentina, como por la persistencia y transformación de redes sociales de parentesco y comunalidad entre áreas de origen y de destino. Lo anterior se pone en relación con la pauta de integración regional que el pueblo mapuche ha construido en la época moderna y las relaciones translocalizadas que siguen favoreciendo una notable movilidad, vinculando sus segmentos rurales y urbanos, peri o semi urbanos.This article offers background information on the migration and mobility of peasants and Mapuche people from the Araucanía, Los Rios and Los Lagos regions to the Argentinian Patagonia, especially to Neuquén and Río Negro, during the second half of the 20th century. This event is part of a larger process of spatial redistribution that includes central Chile, Magallanes and the Patagonia region across the Andes. We describe this economic migration as well as the changes that have taken place because of the oscillation of economies and the relations between Chile and Argentina, or because of the persistence and transformation of kinship and community social nets between the areas of origin and destination. This idea is related to the regional integration pattern that the Mapuche people have created in the modern era as well as to the translocated relationships that keep favoring mobility between its rural, urban and semi urban components.

  9. Museum material reveals a frog parasite emergence after the invasion of the cane toad in Australia

    Directory of Open Access Journals (Sweden)

    Phalen David N

    2010-06-01

    Full Text Available Abstract Background A parasite morphologically indistinguishable from Myxidium immersum (Myxozoa: Myxosporea found in gallbladders of the invasive cane toad (Bufo marinus was identified in Australian frogs. Because no written record exists for such a parasite in Australian endemic frogs in 19th and early 20th century, it was assumed that the cane toad introduced this parasite. While we cannot go back in time ourselves, we investigated whether material at the museum of natural history could be used to retrieve parasites, and whether they were infected at the time of their collection (specifically prior to and after the cane toad translocation to Australia in 1935. Results Using the herpetological collection at the Australian Museum we showed that no myxospores were found in any animals (n = 115 prior to the cane toad invasion (1879-1935. The green and golden bell frog (Litoria aurea, the Peron's tree frog (Litoria peronii, the green tree frog (Litoria caerulea and the striped marsh frog (Limnodynastes peronii were all negative for the presence of the parasite using microscopy of the gallbladder content and its histology. These results were sufficient to conclude that the population was free from this disease (at the expected minimum prevalence of 5% at 99.7% confidence level using the 115 voucher specimens in the Australian Museum. Similarly, museum specimens (n = 29 of the green and golden bell frog from New Caledonia, where it was introduced in 19th century, did not show the presence of myxospores. The earliest specimen positive for myxospores in a gallbladder was a green tree frog from 1966. Myxospores were found in eight (7.1%, n = 112 frogs in the post cane toad introduction period. Conclusion Australian wildlife is increasingly under threat, and amphibian decline is one of the most dramatic examples. The museum material proved essential to directly support the evidence of parasite emergence in Australian native frogs. This parasite can be

  10. Distribution and pathogenicity of Batrachochytrium dendrobatidis in boreal toads from the grand teton area of western wyoming

    Science.gov (United States)

    Murphy, P.J.; St-Hilaire, S.; Bruer, S.; Corn, P.S.; Peterson, C.R.

    2009-01-01

    The pathogen Batrachochytrium dendrobatidis (Bd), which causes the skin disease chytridiomycosis, has been linked to amphibian population declines and extinctions worldwide. Bd has been implicated in recent declines of boreal toads, Bufo boreas boreas, in Colorado but populations of boreal toads in western Wyoming have high prevalence of Bd without suffering catastrophic mortality. In a field and laboratory study, we investigated the prevalence of Bd in boreal toads from the Grand Teton ecosystem (GRTE) in Wyoming and tested the pathogenicity of Bd to these toads in several environments. The pathogen was present in breeding adults at all 10 sites sampled, with a mean prevalence of 67%. In an experiment with juvenile toadlets housed individually in wet environments, 106 zoospores of Bd isolated from GRTE caused lethal disease in all Wyoming and Colorado animals within 35 days. Survival time was longer in toadlets from Wyoming than Colorado and in toadlets spending more time in dry sites. In a second trial involving Colorado toadlets exposed to 35% fewer Bd zoospores, infection peaked and subsided over 68 days with no lethal chytridiomycosis in any treatment. However, compared with drier aquaria with dry refuges, Bd infection intensity was 41% higher in more humid aquaria and 81% higher without dry refuges available. Our findings suggest that although widely infected in nature, Wyoming toads may escape chytridiomycosis due to a slight advantage in innate resistance or because their native habitat hinders Bd growth or provides more opportunities to reduce pathogen loads behaviorally than in Colorado. ?? 2009 International Association for Ecology and Health.

  11. Total On-line Access Data System (TOADS): Phase II Final Report for the Period August 2002 - August 2004

    Energy Technology Data Exchange (ETDEWEB)

    Yuracko, K. L. [YAHSGS LLC, Richland, WA (United States); Parang, M. [YAHSGS LLC, Richland, WA (United States); Landguth, D. C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Coleman, R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2004-09-13

    TOADS (Total On-line Access Data System) is a new generation of real-time monitoring and information management system developed to support unattended environmental monitoring and long-term stewardship of U.S. Department of Energy facilities and sites. TOADS enables project managers, regulators, and stakeholders to view environmental monitoring information in realtime over the Internet. Deployment of TOADS at government facilities and sites will reduce the cost of monitoring while increasing confidence and trust in cleanup and long term stewardship activities. TOADS: Reliably interfaces with and acquires data from a wide variety of external databases, remote systems, and sensors such as contaminant monitors, area monitors, atmospheric condition monitors, visual surveillance systems, intrusion devices, motion detectors, fire/heat detection devices, and gas/vapor detectors; Provides notification and triggers alarms as appropriate; Performs QA/QC on data inputs and logs the status of instruments/devices; Provides a fully functional data management system capable of storing, analyzing, and reporting on data; Provides an easy-to-use Internet-based user interface that provides visualization of the site, data, and events; and Enables the community to monitor local environmental conditions in real time. During this Phase II STTR project, TOADS has been developed and successfully deployed for unattended facility, environmental, and radiological monitoring at a Department of Energy facility.

  12. Living up to its name? The effect of salinity on development, growth, and phenotype of the "marine" toad (Rhinella marina).

    Science.gov (United States)

    Wijethunga, Uditha; Greenlees, Matthew; Shine, Richard

    2016-02-01

    The highly permeable integument of amphibians renders them vulnerable to chemical characteristics of their environment, especially during the aquatic larval stage. As the cane toad (Rhinella marina, Bufonidae) invades southwards along the east coast of Australia, it is encountering waterbodies with highly variable conditions of temperature, pH, and salinity. Understanding the tolerance of toads to these conditions can clarify the likely further spread of the invader, as well as the adaptability of the species to novel environmental challenges. We measured salinity in waterbodies in the field and conducted laboratory trials to investigate the impacts of salinity on toad viability. Eggs and tadpoles from the southern invasion front tolerated the most saline conditions we found in potential spawning ponds during surveys [equivalent to 1200 ppm (3.5 % the salinity of seawater)]. Indeed, high-salinity treatments increased tadpole body sizes, accelerated metamorphosis, and improved locomotor ability of metamorphs (but did not affect metamorph morphology). At very low salinity [40 ppm (0.1 % seawater)], eggs hatched but larvae did not develop past Gosner stage 37. Our study shows that the egg and larval life stages of cane toads can tolerate wide variation in the salinity of natal ponds and that this aspect of waterbody chemistry is likely to facilitate rather than constrain continued southward expansion of the toad invasion front in eastern Australia. PMID:26553545

  13. A new gravimetric reference station in South America: The installation of the Superconducting Gravimeters SG038 at the Argentinian-German Geodetic Observatory AGGO

    Science.gov (United States)

    Wziontek, Hartmut; Nowak, Ilona; Hase, Hayo; Häfner, Michael; Güntner, Andreas; Reich, Marvin; Brunini, Claudio

    2016-04-01

    In April 2015, the Transportable Integrated Geodetic Observatory (TIGO) of BKG was moved from Concepcion / Chile to La Plata / Argentina and was inaugurated in July 2015 as the Argentinian-German Geodetic Observatory (AGGO). In December 2015 the superconducting gravimeter SG038 was set up. The new station is equipped with four stable pillars to serve as a reference station and comparison site for absolute gravimeters in the future. We report about the overland transportation of the SG with the sphere floating, its installation at the new site and the hydrological instrumentation to observe local water storage changes to model near field gravimetric effects. We give an outlook about the first months of gravity time series and assess the drift behaviour after transport.

  14. Foraging modality and plasticity in foraging traits determine the strength of competitive interactions among carnivorous plants, spiders and toads.

    Science.gov (United States)

    Jennings, David E; Krupa, James J; Rohr, Jason R

    2016-07-01

    Foraging modalities (e.g. passive, sit-and-wait, active) and traits are plastic in some species, but the extent to which this plasticity affects interspecific competition remains unclear. Using a long-term laboratory mesocosm experiment, we quantified competition strength and the plasticity of foraging traits in a guild of generalist predators of arthropods with a range of foraging modalities. Each mesocosm contained eight passively foraging pink sundews, and we employed an experimental design where treatments were the presence or absence of a sit-and-wait foraging spider and actively foraging toad crossed with five levels of prey abundance. We hypothesized that actively foraging toads would outcompete the other species at low prey abundance, but that spiders and sundews would exhibit plasticity in foraging traits to compensate for strong competition when prey were limited. Results generally supported our hypotheses. Toads had a greater effect on sundews at low prey abundances, and toad presence caused spiders to locate webs higher above the ground. Additionally, the closer large spider webs were to the ground, the greater the trichome densities produced by sundews. Also, spider webs were larger with than without toads and as sundew numbers increased, and these effects were more prominent as resources became limited. Finally, spiders negatively affected toad growth only at low prey abundance. These findings highlight the long-term importance of foraging modality and plasticity of foraging traits in determining the strength of competition within and across taxonomic kingdoms. Future research should assess whether plasticity in foraging traits helps to maintain coexistence within this guild and whether foraging modality can be used as a trait to reliably predict the strength of competitive interactions. PMID:27061175

  15. Argentinian president Cristina de Kirchner starts commissioning of Atucha II mechanical systems; Inbetriebsetzung der Maschinentechnik in Atucha II durch die Staatspraesidenten Argentiniens

    Energy Technology Data Exchange (ETDEWEB)

    Fabian, Hermann O. [NA-SA-Beratungskomitee zu Designfragen, Erlangen (Germany); Mazzantini, Oscar A. [Nuclearelectrica Argentina SA, Atucha (Argentina). Licensing and Safety

    2012-01-15

    On September 28, 2011, construction of the Atucha II heavy-water reactor plant (CNA II, 745 gross MWe) in Argentina reached another important milestone on its way to completion of the project. In the presence of Argentinian State President Cristina Fernandez de Kirchner, commissioning of the mechanical systems was initiated. The technology of the Atucha reactor facilities, which are fueled with natural uranium, moderated by heavy water (D{sub 2}O) and cooled by light water (H{sub 2}O) (Pressurized Heavy Water Reactor, PHWR), originally was developed by Siemens. These plants were designed alongside the pressurized water reactors using light water. The strict requirements applying to advanced designs in Germany as well as current findings in technical implementation were employed. Major construction and mechanical assembly work has been completed. The primary system has been installed completely. The first core was manufactured at the Argentinian fuel element factory of Conuar and placed into the plant's dry store, which also contains the control and shutdown rods. The heavy water (D{sub 2}O) needed for nuclear operation has been produced and is being stored on the plant premises. Extensive commissioning work is going on in the building for the switching systems including the main and the emergency control rooms. The turbine hall is largely complete, as are the facilities for cooling water supply. The commissioning phase of the plant has been started involving considerable manpower. Some procedures for the later part of the commissioning phase still need to be completed. As a consequence of its sound and qualified basic design and the incorporation of other, new findings, Atucha II in its optimized design will prove to be a safe and reliable plant in operation. The start of commercial operation of Atucha II has been announced for probably late 2012. (orig.)

  16. Assessment of virally vectored autoimmunity as a biocontrol strategy for cane toads.

    Directory of Open Access Journals (Sweden)

    Jackie A Pallister

    Full Text Available BACKGROUND: The cane toad, Bufo (Chaunus marinus, is one of the most notorious vertebrate pests introduced into Australia over the last 200 years and, so far, efforts to identify a naturally occurring B. marinus-specific pathogen for use as a biological control agent have been unsuccessful. We explored an alternative approach that entailed genetically modifying a pathogen with broad host specificity so that it no longer caused disease, but carried a gene to disrupt the cane toad life cycle in a species specific manner. METHODOLOGY/PRINCIPAL FINDINGS: The adult beta globin gene was selected as the model gene for proof of concept of autoimmunity as a biocontrol method for cane toads. A previous report showed injection of bullfrog tadpoles with adult beta globin resulted in an alteration in the form of beta globin expressed in metamorphs as well as reduced survival. In B. marinus we established for the first time that the switch from tadpole to adult globin exists. The effect of injecting B. marinus tadpoles with purified recombinant adult globin protein was then assessed using behavioural (swim speed in tadpoles and jump length in metamorphs, developmental (time to metamorphosis, weight and length at various developmental stages, protein profile of adult globin and genetic (adult globin mRNA levels measures. However, we were unable to detect any differences between treated and control animals. Further, globin delivery using Bohle iridovirus, an Australian ranavirus isolate belonging to the Iridovirus family, did not reduce the survival of metamorphs or alter the form of beta globin expressed in metamorphs. CONCLUSIONS/SIGNIFICANCE: While we were able to show for the first time that the switch from tadpole to adult globin does occur in B. marinus, we were not able to induce autoimmunity and disrupt metamorphosis. The short development time of B. marinus tadpoles may preclude this approach.

  17. Geology and mammalian paleontology of the Horned Toad Hills, Mojave Desert, California, USA

    Science.gov (United States)

    May, S.R.; Woodburne, M.O.; Lindsay, E.H.; Albright, L.B.; Sarna-Wojcicki, A.; Wan, E.; Wahl, D.B.

    2011-01-01

    The Horned Toad Formation includes five lithostratigraphic members that record alluvial fan, fluvial, lake margin, and lacustrine deposition within a relatively small basin just south of the active Garlock fault during the late Miocene to early Pliocene. These sediments experienced northwest-southeast contractional deformation during the Pliocene-Pleistocene associated with basement-involved reverse faults. Member Two of the Horned Toad Formation has yielded 24 taxa of fossil mammals, referred to as the Warren Local Fauna, including Cryptotis sp., cf. Scapanus, Hypolagus vetus, Hypolagus edensis,? Spermophilus sp., Prothomomys warrenensis n. gen., n. sp., Perognathus sp., Repomys gustelyi, Postcopemys valensis, Peromyscus sp. A, Peromyscus sp. B, Jacobsomys dailyi n. sp., Borophagus cf. B. secundus, cf. Agriotherium, Machairodus sp. cf. M. coloradensis, Rhynchotherium sp. cf. R. edensis, Pliomastodon vexillarius, Dinohippus edensis, Teleoceras sp. cf. T. fossiger, cf. Prosthennops, Megatylopus sp. cf. M. matthewi, Hemiauchenia vera, Camelidae gen. et. sp. indet., and the antilocaprid cf. Sphenophalos. The majority of fossil localities are confined to a 20 m thick stratigraphic interval within a reversed polarity magnetozone. The fauna demonstrates affinity with other late Hemphillian faunas from California, Nevada, Nebraska, Texas, and Mexico. The Lawlor Tuff, dated elsewhere in California at 4.83 ?? 0.04 Ma and geochemically identified in the Horned Toad Formation, overlies most of the fossil mammal localities. Magnetic polarity data are correlated with Chrons 3n.3r, 3n.3n, and 3n.2r, suggesting an age of approximately 5.0 - 4.6 Ma. These constraints indicate an age for the late Hemphillian Warren Local Fauna of 4.85 - 5.0 Ma. ?? Society of Vertebrate Paleontology November 2011.

  18. AVALIATION OF VENTILATORY PATTERN IN THE TOAD RHINELLA SCHNEIDERI (ANURA: BUFONIDAE)

    OpenAIRE

    FERNANDES, Marcelo dos Santos; GIUSTI, HumbertoGLASS; Glass, Mogens Lesner

    2010-01-01

    Amphibians ventilated their lungs by buccal pumping mechanism, which was first described in 1969 as a model for studying anurans respiration. Since amphibians do not have alveoli in their lungs, wecalculated to the toad Rhinella schneideri the equivalent lung ventilation from the equation VEFF = (VLCO2·RT)/PLCO2. We analyzed buccal and pulmonary pressures, respiratory volumes, lung and buccalventilation, and ventilation frequency. [VE (12,1 ± 0,6ml BTPS.min-1.kg-1 ) ; VEB (164,3 ± 2,2ml BTPS....

  19. NHE-1 sequence and expression in toad, snake and fish red blood cells

    DEFF Research Database (Denmark)

    Thomsen, Steffen Nyegaard; Wang, Tobias; Kristensen, Torsten

    Red blood cells (RBC) from reptiles appear not to express regulatory volume increase (RVI) upon shrinkage (Kristensen et al., 2008). In other vertebrates, the RVI response is primarily mediated by activation of the Na+/H+ exchanger (NHE-1) and we, therefore decided to investigate whether red cells...... of reptiles express a different NHE-1 that responds less to volume activation compared to other vertebrates or simply lack the Na+/H+ exchanger. Using various tissues from the ball python (Python regius), Cane toad (Bufo marinus) and European perch (Perca fluviatilis), cDNA libraries were created and...

  20. A comparison of the uptake of [1-14C]palmitate into cell fractions of the perfused toad, chick and guinea-pig heart.

    Science.gov (United States)

    Gloster, J; Achillea, M; Harris, P

    1977-01-01

    1. The incorporation and washout of [1-14C]palmitate in the subcellular fractions of toad, chick and guinea-pig hearts has been studied at warm and cold temperatures. 2. Maximal FFA radioactivity generally occurred in the microsomal fraction. Washout of radioactivity in chick and guinea-pig hearts virtually ceased in the cold, while in the toad it was only moderately affected. 3. The microsomal esterification process was temperature dependent. It was most active in the guinea-pig and least active in the toad. PMID:318436

  1. Interactive effects of maternal and environmental exposure to coal combustion wastes decrease survival of larval southern toads (Bufo terrestris)

    International Nuclear Information System (INIS)

    We conducted a mesocosm study to assess the individual and interactive effects of previous maternal exposure and larval exposure to trace element-laden sediments on southern toads (Bufo terrestris). Previous maternal exposure to coal combustion wastes (CCW) reduced larval survival to metamorphosis up to 57% compared to larvae of unexposed females. Larvae reared on CCW accumulated significant concentrations of trace elements resulting in extended larval periods, reduced growth rates, and reduced mass at metamorphosis. However, the effects were dependent on age of sediments, suggesting the effects of contaminants from CCW may be partially ameliorated over time through the reduced bioavailability of trace elements in aged CCW. Most importantly, maternal exposure to contaminants coupled with larval exposure to fresh CCW interacted to reduce survival to metamorphosis by 85% compared to reference conditions. Our study yields further evidence that disposal of CCW in aquatic basins potentially creates ecological traps for some amphibian populations. - Highlights: ► The interaction of maternal exposure and larval exposure to CCW reduced survival. ► Previous maternal exposure to CCW had a latent effect on survival to metamorphosis. ► Larval southern toads exposed to CCW experienced prolonged larval periods. ► Larval southern toads exposed to CCW had reduced growth rates. ► Larval southern toads exposed to CCW had reduced mass at metamorphosis. - Maternal and environmental exposure to coal combustion wastes interact to decrease survival in larval amphibians.

  2. Modification of a prey catching response and the development of behavioral persistence in the fire-bellied toad (Bombina orientalis).

    Science.gov (United States)

    Ramsay, Zachary J; Ikura, Juntaro; Laberge, Frédéric

    2013-11-01

    The present report investigated how fire-bellied toads (Bombina orientalis) modified their response in a prey catching task in which the attribution of food reward was contingent on snapping toward a visual stimulus of moving prey displayed on a computer screen. Two experiments investigated modification of the snapping response, with different intervals between the opportunity to snap at the visual stimulus and reward administration. The snapping response of unpaired controls was decreased compared with the conditioned toads when hour or day intervals were used, but intervals of 5 min produced only minimal change in snapping. The determinants of extinction of the response toward the visual stimulus were then investigated in 3 experiments. The results of the first experiment suggested that increased resistance to extinction depended mostly on the number of training trials, not on partial reinforcement or the magnitude of reinforcement during training. This was confirmed in a second experiment showing that overtraining resulted in resistance to extinction, and that the pairing of the reward with a response toward the stimulus was necessary for that effect, as opposed to pairing reward solely with the experimental context. The last experiment showed that the time elapsed between training trials also influenced extinction, but only in toads that received few training trials. Overall, the results suggest that toads learning about a prey stimulus progress from an early flexible phase, when an action can be modified by its consequences, to an acquired habit characterized by an increasingly inflexible and automatic response. PMID:23668694

  3. Diet of southern toads (Bufo terrestris) in loblolly pine (Pinus taeda) stands subject to coarse woody debris manipulations.

    Energy Technology Data Exchange (ETDEWEB)

    Moseley, Kurtis R.; Steven B. Castleberry; James L. Hanula; Mark Ford.

    2005-04-01

    ABSTRACT In the southeastern United States, coarse woody debris (CWD) typically harbors high densities of invertebrates. However, its importance as a foraging substrate for southeastern amphibians is relatively unknown. We examined effects of CWD manipulations on diet composition of southern toads (Bufo terrestris) in upland loblolly pine (Pinus taeda) stands in the Coastal Plain of South Carolina. Twelve 9.3-ha plots were assigned one of the following treatments: removal- all CWD _10 cm in diameter and _60 cm long removed; downed- five-fold increase in volume of down CWD; and unmanipulated control stands. We collected southern toads _4 cm snout-vent length (SVL) during 14 d sampling periods in June and October 2002, June 2003 and during a 28 d sampling period in April 2003. We collected 80, 36 and 35 southern toads in control, downed and removal treatments, respectively. We found no difference in relative abundance or frequency of invertebrate groups consumed among treatments (P.0.05). Average body weight (g), SVL (cm) and stomach content weight (g wet) of individuals also were similar among treatments (P . 0.05). The role of CWD as a foraging substrate for southern toads in loblolly pine stands of the southeastern Coastal Plain may be negligible, at least in the early stages of decay.

  4. Aversive and non-reward learning in the fire-bellied toad using familiar and unfamiliar prey stimuli

    Directory of Open Access Journals (Sweden)

    Ursula DICKE, Antje HEIDORN, Gerhard ROTH

    2011-12-01

    Full Text Available The present study investigated how snapping behavior toward familiar and unfamiliar prey is modified by reward omission and aversive conditioning in the fire-bellied toad Bombina orientalis. Toads were trained to snap at cricket images by rewarding them with live crickets. The task was learned, and the learning criterion (10 snapping responses within 2 minutes was reached in all individuals investigated. Subsequent reward omission did not alter the frequency of snapping to the familiar cricket stimulus. Snapping decreased only in some individuals, when a mild foot shock was applied at snapping. However, at presentation of images of hitherto unfamiliar meal worms and foot-shock application at snapping to the stimulus, the majority of toads diminished snapping significantly. Snapping responses decreased more rapidly, when snapping at meal worms was not rewarded or a footshock was applied uncorrelated to the presentation of or snapping at meal worms. These results demonstrate that in toads familiarity and unfamiliarity of prey stimuli are important factors in aversive learning, because well-trained responses to familiar stimuli become immune against reward omission. Furthermore, at presentation of unfamiliar stimuli, omission of reward and uncorrelated footshock had a stronger aversive effect than correlated footshock [Current Zoology 57 (6: 709–716, 2011].

  5. Aversive and non-reward learning in the fire-bellied toad using familiar and unfamiliar prey stimuli

    Institute of Scientific and Technical Information of China (English)

    Ursula DICKE; Antje HEIDORN; Gerhard ROTH

    2011-01-01

    The present study investigated how snapping behavior toward familiar and unfamiliar prey is modified by reward omission and aversive conditioning in the fure-bellied toad Bombina orientalis.Toads were trained to snap at cricket images by rewarding them with live crickets.The task was learned,and the learning criterion (10 snapping responses within 2 minutes) was reached in all individuals investigated.Subsequent reward omission did not alter the frequency of snapping to the familiar cricket stimulus.Snapping decreased only in some individuals,when a mild foot shock was applied at snapping.However,at presentation of images of hitherto unfamiliar meal worms and foot-shock application at snapping to the stimulus,the majority of toads diminished snapping significantly.Snapping responses decreased more rapidly,when snapping at meal worms was not rewarded or a footshock was applied uncorrelated to the presentation of or snapping at meal worms.These results demonstrate that in toads familiarity and unfamiliarity of prey stimuli are important factors in aversive learning,because well-trained responses to familiar stimuli become immune against reward omission.Furthermore,at presentation of unfamiliar stimuli,omission of reward and uncorrelated footshock had a stronger aversive effect than correlated footshock [Current Zoology 57 (6):709-716,2011 ].

  6. Larger body size at metamorphosis enhances survival, growth and performance of young cane toads (Rhinella marina.

    Directory of Open Access Journals (Sweden)

    Elisa Cabrera-Guzmán

    Full Text Available Body size at metamorphosis is a key trait in species (such as many anurans with biphasic life-histories. Experimental studies have shown that metamorph size is highly plastic, depending upon larval density and environmental conditions (e.g. temperature, food supply, water quality, chemical cues from conspecifics, predators and competitors. To test the hypothesis that this developmental plasticity is adaptive, or to determine if inducing plasticity can be used to control an invasive species, we need to know whether or not a metamorphosing anuran's body size influences its subsequent viability. For logistical reasons, there are few data on this topic under field conditions. We studied cane toads (Rhinella marina within their invasive Australian range. Metamorph body size is highly plastic in this species, and our laboratory studies showed that larger metamorphs had better locomotor performance (both on land and in the water, and were more adept at catching and consuming prey. In mark-recapture trials in outdoor enclosures, larger body size enhanced metamorph survival and growth rate under some seasonal conditions. Larger metamorphs maintained their size advantage over smaller siblings for at least a month. Our data support the critical but rarely-tested assumption that all else being equal, larger body size at metamorphosis is likely to enhance an individual's long term viability. Thus, manipulations to reduce body size at metamorphosis in cane toads may help to reduce the ecological impact of this invasive species.

  7. Differences and Similarities among Parotoid Macrogland Secretions in South American Toads: A Preliminary Biochemical Delineation

    Directory of Open Access Journals (Sweden)

    Juliana Mozer Sciani

    2013-01-01

    Full Text Available Amphibians are known by cutaneous glands, spread over the skin, containing toxins (proteins, peptides, biogenic amines, steroidal bufadienolides, and alkaloids used as chemical defense against predators and microbial infection. Toads are characterized by the presence of parotoid macroglands. The common toads have lately been divided into two genera: Bufo (Europe, Asia, and Africa and Rhinella (South America. Basal Rhaebo genus is exclusively of Central America and Amazon region. Although Rhinella and Rhaebo are related, species may share differences due to the diversity of environments that they live in. In this work, we have performed a biochemical characterization of the components of the poison of eight Rhinella species and one Rhaebo by means of RP-HPLC with either UV or MS detection and by SDS-PAGE, in order to verify whether phylogenetic and biological differences, such as habitat, diet, and defensive strategies, between them may also be reflected in poison composition. Although some components were common among the secretions, we were able to identify exclusive molecules to some species. The fact that closely related animals living in different habitats secrete different molecules into the skin is an indication that biological features, and not only evolution, seem to directly influence the skin secretion composition.

  8. Diffusion of 133Xe through frog skins, toad bladders, and water boundary layers

    International Nuclear Information System (INIS)

    We have measured the total permeability coefficients P as a function of stirring frequency ω for 133Xe through frog skins and toad bladders. The permeability coefficients for the frog skins and toad bladders proper are, respectively, P/sub m/ = (3.9 +- 0.8) x 10-4 cm/s and (7.4 +- 4.2) x 10-4 cm/s. ''Unstirred'' water layer thickness delta is determined concurrently, from the frequency dependence of P(ω); the result for frog skin is delta = (0.060 +- 0.016)/√ω(rad/s) cm. The stirring frequency range is from ω = 7.5 rad/s (72 rpm) to 55 rad/s (530 rpm). The results support the conclusions that the principal barrier to Xe diffusion in these epithelia is inter- and intracellular water, and that the diffusion is passive and rapid. The experimental method may be straightforwardly adapted to the measurement of diffusion or counterdiffusion of any gamma-radioactive soluble or partly soluble solute through any flat membrane or through a solvent. We estimate the amount of total body-absorbed radioactivity due to environmental 133Xe to be 50 fCi for an ambient concentration of 2.6 pCi/m3 of air

  9. Ba2+-inhibitable 86Rb+ fluxes across membranes of vesicles from toad urinary bladder

    International Nuclear Information System (INIS)

    86Rb+ fluxes have been measured in suspensions of vesicles prepared from the epithelium of toad urinary bladder. A readily measurable barium-sensitive, ouabain-insensitive component has been identified; the concentration of external Ba2+ required for half-maximal inhibition was 0.6 mM. The effects of externally added cations on 86Rb+ influx and efflux have established that this pathway is conductive, with a selectivity for K+, Rb+ and Cs+ over Na+ and Li+. The Rb+ uptake is inversely dependent on external pH, but not significantly affected by internal Ca2+ or external amiloride, quinine, quinidine or lidocaine. It is likely, albeit not yet certain, that the conductive Rb+ pathway is incorporated in basolateral vesicles oriented right-side-out. It is also not yet clear whether this pathway comprises the principle basolateral K+ channel in vivo, and that its properties have been unchanged during the preparative procedures. Subject to these caveats, the data suggest that the inhibition by quinidine of Na+ transport across toad bladder does not arise primarily from membrane depolarization produced by a direct blockage of the basolateral channels. It now seems more likely that the quinidine-induced elevation of intracellular Ca2+ activity directly blocks apical Na+ entry

  10. Functional assessment of toad parotoid macroglands: a study based on poison replacement after mechanical compression.

    Science.gov (United States)

    Jared, Simone G S; Jared, Carlos; Egami, Mizue I; Mailho-Fontana, Pedro L; Rodrigues, Miguel T; Antoniazzi, Marta M

    2014-09-01

    Toads have a pair of parotoid macroglands behind the eyes that secrete poison used in passive defence against predators. These macroglands are composed of juxtaposed alveoli, each one bearing a syncytial gland, all connected to the exterior by ducts. When the parotoids are bitten, the poison is expelled on the predator oral mucosa in the form of jets, causing several pharmacological actions. After poison release, the empty secretory syncytia immediately collapse in the interior of their respective alveoli and gradually start refilling. After parotoid manual compression, simulating a predator's bite, we studied, by means of morphological methods, the replacement of the poison inside the alveoli. The results showed that after compression, a considerable number of alveoli remained intact. In the alveoli that were effectively affected the recovery occurs in different levels, from total to punctual and often restrict to some areas of the syncytia. The severely affected alveoli seem not recover their original functional state. The fact that only a part of the parotoid alveoli is compressed during an attack seems to be crucial for toad survival, since the amphibian, after being bitten by a predator, do not lose all its poison stock, remaining protected in case of new attacks. PMID:24911375

  11. Association preference and mechanism of kin recognition in tadpoles of the toad Bufo melanostictus

    Indian Academy of Sciences (India)

    Lilly Margaret Eluvathingal; Bhagyashri A Shanbhag; Srinivas K Saidapur

    2009-09-01

    In experiments with specially designed choice tanks, tadpoles of Bufo melanostictus spend significantly greater amounts of time near kin than near non-kin. However, in the absence of kin members, they prefer to spend more time near non-kin rather than stay away in isolation in the opposite blank zone with no company. This implies that association of toad tadpoles with their kin is due to attraction rather than repulsion from non-kin. Experiments designed to elucidate the sensory basis of kin recognition showed that toad tadpoles recognize their kin based on chemical cues rather than visual cues. They can also discriminate between homospecific non-kin and heterospecific (Sphaerotheca breviceps) tadpoles since the tadpoles spent significantly greater amounts of time near the former than near the latter. These findings suggest that where kin members are unavailable, selection may have favoured living with non-kin so as to derive benefits from group living and that a phenotype-matching mechanism may operate for both kin and species discrimination in B. melanostictus.

  12. spatial distribution pattern of the steppe toad-headed lizard (phrynocephalus frontalis) and its influencing factors

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    spatial distribution patterns are associated with life history and behavioral adaptations of animals.for studying the spatial distribution pattern of the steppe toad-headed lizard (phrynocephalusfrontalis) and its influencing factors,we conducted experiments in hunshandake sandy land in inner mongolia,china in july 2009.by calculating the clustered indices,we found that the lizard was aggregately distributed when the sampling quadrat was smaller than 10 m × 10 m,and uniformly distributed when it was greater than 10 m × 10 m.the nearest neighbor rule showed a clustering distribution pattern for p frontalis and the distribution pattern was quadrat-sampling dependent.furthermore,the cluster was determined by environmental factors when the sampling quadrat was smaller than 20 m × 20 m,but it was determined by both environmental factors and characteristics of the lizard when it was larger than 20 m × 20 m.our results suggested that the steppe toad-headed lizards tended to aggregate into suitable habitat patches in desert areas.additionally,we discussed that the lizard aggregation could be potentially used as an indictor of movement of sand dunes.

  13. CRED Optical Validation Data at the island of Ta'u in American Samoa, 2004 to Support Benthic Habitat Mapping (TOAD)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Optical validation data were collected using a Tethered Optical Assessment Device (TOAD), an underwater sled equipped with an underwater digital video camera and...

  14. CRED Optical Validation Data at the island of Ofu and Olosega in American Samoa, 2012 to support Benthic Habitat Mapping (TOAD)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Optical validation data were collected using the Tethered Optical Assessment Device (TOAD), a sled equipped with underwater video camera, still camera and lights....

  15. CRED Optical Validation Data at the islands of Ofu and Olosega in American Samoa, 2004 to Support Benthic Habitat Mapping (TOAD)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Optical validation data were collected using a Tethered Optical Assessment Device (TOAD), an underwater sled equipped with an underwater digital video camera and...

  16. CRED Optical Validation Data at the island of Ta'u in American Samoa, 2006 to support Benthic Habitat Mapping (TOAD)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Optical validation data were collected using a Tethered Optical Assessment Device (TOAD), an underwater sled equipped with an underwater digital video camera and...

  17. CRED Optical Validation Data at the island of Ofu and Olosega in American Samoa, 2006 to support Benthic Habitat Mapping (TOAD)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Optical validation data were collected using a Tethered Optical Assessment Device (TOAD), an underwater sled equipped with an underwater digital video camera and...

  18. CRED Optical Validation Data at the island of Ta'u in American Samoa, 2012 to support Benthic Habitat Mapping (TOAD)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Optical validation data were collected using the Tethered Optical Assessment Device (TOAD), a sled equipped with underwater video camera, still camera and lights....

  19. Inhibition of Batrachochytrium dendrobatidis Caused by Bacteria Isolated from the Skin of Boreal Toads, Anaxyrus (Bufo) boreas boreas, from Grand Teton National Park, Wyoming, USA

    OpenAIRE

    Park, Shawna T; Collingwood, Amanda M; Sophie St-Hilaire; Sheridan, Peter P.

    2014-01-01

    The chytrid fungus Batrachochytrium dendrobatidis is a significant cause of the worldwide decline in amphibian populations; however, various amphibian species are capable of coexisting with B. dendrobatidis. Among them are boreal toads (Anaxyrus (Bufo) boreas boreas) located in Grand Teton National Park (GTNP) in Wyoming, USA. The purpose of this study was to identify cultivable bacterial isolates from the skin microbiota of boreal toads from GTNP and determine if they were capable of inhibit...

  20. New regional record and notes on historical specimens of Gunther Toad Duttaphrynus hololius with comments on other southeastern Indian congeners

    OpenAIRE

    Srinivasulu, B.; S.R. Ganesh; C. Srinivasulu

    2013-01-01

    We report on the finding of the Günther Toad Duttaphrynus hololius from Visakhapatnam and discuss aspects of its distribution based on our species distribution modeling. We also provide data on historically collected specimens and refine its intra-specific variation, provide an up-to-date chresonymy and comment on the validity of earlier reported diagnosis. Lastly, we remark on some misidentification-mediated dubious southern Indian records of another, related congener, the Marbled Toad D. ...

  1. The effects of drought on population structure, activity, and orientation of toads Bufo quercicus and B. terrestris at a temporary pond

    Science.gov (United States)

    Dodd, C.K., Jr.

    1994-01-01

    From 1985 through 1990, I monitored the populations of two species of toads, Bufo quercicus and B. terrestris, at a temporary pond in the xeric uplands of north-central Florida. A drift fence with pitfall traps completely encircled the pond basin; the fence was monitored 5 days per week throughout the year. The 5-year study coincided with a severe regional drought that resulted in generally short hydroperiods at unpredictable times of the year. More than 800 toads were captured. Successful metamorphosis never occurred at the pond although toads continued to visit it throughout the study. The sex ratio was male biased in B. quercicus but not in B. terrestris, although significant variation was observed from one year to the next. Likewise, the size-class structure and length-weight patterns varied among species, sexes, and years. Although fewer toads entered the pond basin as the study progressed, toads may have gone elsewhere to breed or they may have remained in refugia. Thus, decreased capture does not necessarily indicate that a drought-related population decline occurred. Drought may have disrupted normal arrival patterns and length of stay within the pond basin. Drought also could be responsible for variation in annual size-class structure of captured toads. The uncertainty of the hydroperiod both spatially and temporally in adjacent breeding sites, the ability of toads to move long distances with the potential for migration between breeding sites, and the lack of specificity in the choice of breeding sites (i.e. permanent versus different types of temporary wetlands) may lead to the formation of metapopulations in the xeric upland habitats of north-central Florida. Long-term monitoring under a variety of climatic conditions is needed to assess the effects of drought and other types of environmental stresses on toad populations.

  2. Habitat suitability of patch types:A case study of the Yosemite toad

    Institute of Scientific and Technical Information of China (English)

    Christina T.LIANG; Thomas J.STOHLGREN

    2011-01-01

    Understanding patch variability is crucial in understanding the spatial population structure of wildlife species,especially for rare or threatened species.We used a well-tested maximum entropy species distribution model (Maxent) to map the Yosemite toad (Anaxyrus (= Bufo) canorus) in the Sierra Nevada mountains of California.Twenty-six environmental variables were included in the model representing climate,topography,land cover type,and disturbance factors (e.g.,distances to agricultural lands,fire perimeters,and timber harvest areas) throughout the historic range of the toad.We then took a novel approach to the study of spatially structured populations by applying the species-environmental matching model separately for 49 consistently occupied sites of the Yosemite toad compared to 27 intermittently occupied sites.We found that the distribution of the entire population was highly predictable (AUC= 0.95±0.03 SD),and associated with low slopes,specific vegetation types (wet meadow,alpine-dwarf shrub,montane chaparral,red fir,and subalpine conifer),and warm temperatures.The consistently occupied sites were also associated with these same factors,and they were also highly predictable (AUC= 0.95±0.05 SD).However,the intermittently occupied sites were associated with distance to fire perimeter,a slightly different response to vegetation types,distance to timber harvests,and a much broader set of aspect classes (AUC = 0.90±0.11 SD).We conclude that many studies of species distributions may benefit by modeling spatially structured populations separately.Modeling and monitoring consistently-occupied sites may provide a realistic snapshot of current speciesenvironment relationships,important climatic and topographic patterns associated with species persistence patterns,and an understanding of the plasticity of the species to respond to varying climate regimes across its range.Meanwhile,modeling and monitoring of widely dispersing individuals and intermittently occupied

  3. EFFECT OF ANGELICA SINENSIS ON AFFERENT DISCHARGE OF SINGLE MUSCLE SPINDLE IN TOADS

    Institute of Scientific and Technical Information of China (English)

    高云芳; 樊小力

    2004-01-01

    Objective In drugs for invigorating blood circulation, to find a herb that can stimulate afferent discharge of muscle spindle. Methods A single muscle spindle was isolated from sartorial muscle of toad. Using air-gap technique, afferent discharge of the muscle spindle was recorded. Effects of Angelica Sinensis, Salvia Miltiorrhiza, and Safflower on afferent discharge of the muscle spindle were observed. Results Angelica Sinensis could distinctly increase afferent discharge frequency of the muscle spindle, and this increase was dose-dependent. But Salvia Miltiorrhiza and Safflower had no this excitatory effect. Conclusion It is known that Angelica Sinensis can invigorate blood circulation, and we have found its excitatory effect on muscle spindle which makes it possible to serve people with muscle atrophy if more evidences from clinical experiments are available.

  4. Membrane potential plays a dual role for chloride transport across toad skin

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Rasmussen, B E

    1983-01-01

    -dependent currents are not caused by a trivial Goldmand-type rectification and ion redistributions following transepithelial potential pertubations. Extended with a dynamic Cl- permeability in the apical membrane according to a Hodgkin-Huxley kinetic scheme, the model predicts voltage clamp data which closely......The Cl- -current through toad skin epithelium depends on the potential in a way consistent with a potential-controlled Cl- permeability. Computer analysis of the Koefoed-Johnsen Ussing two-membrane model provided with constant membrane permeabilities indicates that the voltage- and time...... resemble experimental observations. This extension of the classic frog skin model implies that the Cl- permeability is activated by a voltage change caused by the inward Na+ current through the apical membrane....

  5. KARYOTYPIC STUDY OF THE COMMON INDIAN TOAD, DUTTAPHRYNUS MELANOSTICTUS, FROM JAMMU AND KASHMIR, INDIA

    Directory of Open Access Journals (Sweden)

    Neelam Saba

    2014-01-01

    Full Text Available Karyotypic study of two sexes of the toad species, Duttaphrynus melanostictus, was carried out using giemsa staining, C- banding and NOR banding methods, from Jammu and Kashmir, India. The basic chromosome number was found to be 2n=22, fundamental arm number (NF was 44 with all the biarmed chromosomes and no sex chromosome heteromorphism was found. Cbanding and NOR banding was also performed. Paracentric C-band was on the long arm of first homologous pair. Centromeric heterochromatin appeared as darkly stained C-bands on all the chromosomes of diploid complement, whereas Ag-NOR staining showed a pair of nucleolar organizer regions present on pair no. 7 on short arm i.e. 7p in both male and female karyotypes.

  6. Cytological evidence for population-specific sex chromosome heteromorphism in Palaearctic green toads (Amphibia, Anura)

    Indian Academy of Sciences (India)

    G Odierna; G Aprea; T Capriglione; S Castellano; E Balletto

    2007-06-01

    A chromosome study was carried out on a number of European and Central Asiatic diploid green toad populations by means of standard and various other chromosome banding and staining methods (Ag-NOR-, Q-, CMA3-, late replicating [LR] banding pattern, C- and sequential C-banding + CMA3 + DAPI). This study revealed the remarkable karyological uniformity of specimens from all populations, with the only exception being specimens from a Moldavian population, where one chromosome pair was heteromorphic. Though similar in shape, size and with an identical heterochromatin distribution, the difference in the heteromorphic pair was due to a large inverted segment on its long arms. This heteromorphism was restricted to females, suggesting a female heterogametic sex chromosome system of ZZ/ZW type at a very early step of differentiation.

  7. Rapid differentiation of sexual signals in invasive toads: call variation among populations.

    Science.gov (United States)

    Yasumiba, Kiyomi; Duffy, Richard L; Parsons, Scott A; Alford, Ross A; Schwarzkopf, Lin

    2016-01-01

    Advertisement calls tend to differ among populations, based on morphological and environmental factors, or simply geographic distance, in many taxa. Invasive cane toads (Rhinella marina) were introduced to Australia in 1935 and their distribution has expanded at increasing rates over time. Rapid evolution occurred in morphological and behavioural characters that accelerate dispersal, but the effects of rapid expansion on sexual signals have not been examined. We collected advertisement calls from four populations of different ages since invasion, and analysed the geographic differentiation of seven call parameters. Our comparisons indicate that the calls of R. marina differ among Australian populations. The signal variation was not simply clinal with respect to population age, climate, or morphological differentiation. We suggest that selection on signalling among populations has been idiosyncratic and may reflect local female preferences or adaptation to environmental factors that are not clinal such as energy availability. PMID:27328666

  8. Use of lidocaine, propranolol, amiodarone, and verapamil in toad envenoming (genus bufo in dogs

    Directory of Open Access Journals (Sweden)

    M. SAKATE

    2001-12-01

    Full Text Available Toad envenoming in dogs can cause death by cardiac fibrilation (CVF. Traditional therapy consists mainly of atropine and propranolol, the last one used to prevent the CVF, that is preceded by negative ventricular deflections (NVDs in the QRS complex of the electrocardiogram. This study intended to verify, comparatively, the lidocaine, propranolol, amiodarone, and verapamil abilities to prevent CVF in experimentally envenomed dogs. Thirty-six dogs were divided into 6 groups (GL, GP, GA, GV, GST, and GSV with n=6; the dogs were submitted to volatile anaesthesia. The animals of the groups GL, GP, GA, and GV received 0.38g of toad venom through oro-gastric catheter and were treated with the following drugs respectively: lidocaine (4mg/Kg, propranolol (0.1mg/Kg, amiodarone (8mg/Kg, and verapamil (2mg/Kg. These drugs were repeated if NVDs reappeared with cardiac frequency >150, GST was not treated and GSV was just anaesthetized. The following results were obtained: GL, NVDs present in 4 animals, 100% recuperation with 3.66 doses/animal; GP, NVDs present in 2 animals, 100% recuperation with 1.66 dose/animal, with bradycardia at the anaesthetic return; GA, NVDs present in 3 animals, 33.33% recuperation with 1.5 dose/animal; GV, NVDs present in 4 animals, 100% recuperation with 2.16 doses/animal; GST, NVD present in 6 animals, 100% death and GSV, NVDs absent, 100% recuperation. As a conclusion, the anaesthetic proceedings used, did not cause NVDs, the envenoming that was not treated was lethal, and among the antiarrhythmics drugs used, verapamil was the most efficient, as it did not cause any serious bradycardia at the anaesthetic return and did not require repeated administrations. For lidocaine, it was efficient but required various administrations; amiodarone could not prevent the death of 4 animals; propranolol was efficient in relation to NVDs control, but caused serious bradycardia at the anaesthetic return.

  9. Multi-level effects of low dose rate ionizing radiation on southern toad, Anaxyrus [Bufo] terrestris

    International Nuclear Information System (INIS)

    Despite their potential vulnerability to contaminants from exposure at multiple life stages, amphibians are one of the least studied groups of vertebrates in ecotoxicology, and research on radiation effects in amphibians is scarce. We used multiple endpoints to assess the radiosensitivity of the southern toad (Anaxyrus [Bufo] terrestris) during its pre-terrestrial stages of development -embryonic, larval, and metamorphic. Toads were exposed, from several hours after oviposition through metamorphosis (up to 77 days later), to four low dose rates of 137Cs at 0.13, 2.4, 21, and 222 mGy d-1, resulting in total doses up to 15.8 Gy. Radiation treatments did not affect hatching success of embryos, larval survival, or the length of the larval period. The individual family variation in hatching success of embryos was larger than the radiation response. In contrast, newly metamorphosed individuals from the higher dose-rate treatments had higher mass and mass/length body indices, a measure which may relate to higher post-metamorphic survival. The increased mass and index at higher dose rates may indicate that the chronic, low dose rate radiation exposures triggered secondary responses. Additionally, the increases in growth were linked to a decrease in DNA damage (as measured by the Comet Assay) in red blood cells at a dose rate of 21mGy d-1 and a total dose of 1.1 Gy. In conclusion, the complex effects of low dose rates of ionizing radiation may trigger growth and cellular repair mechanisms in amphibian larvae

  10. Multi-Level Effects of Low Dose Rate Ionizing Radiation on Southern Toad, Anaxyrus [Bufo] terrestris.

    Directory of Open Access Journals (Sweden)

    Karolina Stark

    Full Text Available Despite their potential vulnerability to contaminants from exposure at multiple life stages, amphibians are one of the least studied groups of vertebrates in ecotoxicology, and research on radiation effects in amphibians is scarce. We used multiple endpoints to assess the radiosensitivity of the southern toad (Anaxyrus [Bufo] terrestris during its pre-terrestrial stages of development -embryonic, larval, and metamorphic. Toads were exposed, from several hours after oviposition through metamorphosis (up to 77 days later, to four low dose rates of 137Cs at 0.13, 2.4, 21, and 222 mGy d-1, resulting in total doses up to 15.8 Gy. Radiation treatments did not affect hatching success of embryos, larval survival, or the length of the larval period. The individual family variation in hatching success of embryos was larger than the radiation response. In contrast, newly metamorphosed individuals from the higher dose-rate treatments had higher mass and mass/length body indices, a measure which may relate to higher post-metamorphic survival. The increased mass and index at higher dose rates may indicate that the chronic, low dose rate radiation exposures triggered secondary responses. Additionally, the increases in growth were linked to a decrease in DNA damage (as measured by the Comet Assay in red blood cells at a dose rate of 21 mGy d-1 and a total dose of 1.1 Gy. In conclusion, the complex effects of low dose rates of ionizing radiation may trigger growth and cellular repair mechanisms in amphibian larvae.

  11. Bm-TFF2, a toad trefoil factor, promotes cell migration, survival and wound healing

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yong [Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); Yu, Guoyu [Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); Department of Biochemistry, Kunming Medical College, Kunming, Yunnan 650032 (China); Xiang, Yang [Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); Wu, Jianbo [Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223 (China); Jiang, Ping [Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); Lee, Wenhui [Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223 (China); Zhang, Yun, E-mail: zhangy@mail.kiz.ac.cn [Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223 (China)

    2010-07-30

    Research highlights: {yields} Bm-TFF2 binds to epithelial cells and induces cell migration and wound healing. {yields} Bm-TFF2 suppresses cell apoptosis. {yields} Bm-TFF2 has no effect on cell proliferation. -- Abstract: Toad skin is naked and continually confronted by various injurious factors. Constant skin renewal and repairs occur frequently. However, the mechanisms of the renewal and repair have not clearly elucidated. In our previous work, a trefoil factor (TFF), Bm-TFF2, has been purified from the Bombina maxima skin and characterized as a platelet agonist. The mRNA of TFFs in toad skin was up-regulated greatly during the metamorphosis, indicating a pivotal role of TFFs in amphibian skin. Here, we presented the effects of Bm-TFF2 on the cell migration, apoptosis and proliferation. Bm-TFF2 bound to epithelial cells and showed strong cell motility activity. At the concentrations of 1-100 nM, Bm-TFF2-induced migration of human epithelial AGS and HT-29 cells, and rat intestinal epithelial IEC-6 cell lines. The in vitro wound healing assay also verified the activity of Bm-TFF2. Bm-TFF2 could also inhibit cell apoptosis induced by ceramide and sodium butyrate. The cell migration-promoting activity was abolished by MEK1 inhibitors, U0126 and PD98059, suggesting that ERK1/2 activation is crucial for Bm-TFF2 to stimulate cell migration. Taken together, Bm-TFF2 promoted wound healing by stimulating cell migration via MAPK pathway and preventing cell apoptosis. The potent biological activity of Bm-TFF2 makes it a useful molecular tool for further studies of structure-function relationship of the related human TFFs.

  12. Nux Vomica 200 CH reduced acute hypnotic effect of alcohol in young toads

    Directory of Open Access Journals (Sweden)

    Nirmal Sukul

    2012-09-01

    Full Text Available Potentized Nux Vomica has been reported to produce antialcoholic effect in mice, rats and toads. The effect relates to consumption of alcohol and alcohol-induced loss of righting reflex (RR. RR’s maintain normal erect posture of an animal and are centrally controlled in the midbrain. In the present study young toads, Duttaphrynus melanostictus were first treated with Nux vomica 200 CH and then partially immersed in 209 mM ethanol solution in such a way that their head remained above the level of ethanol solution. Toadlets were removed from the ethanol solution every 10 min, tested for the loss of RR and returned to the ethanol solution. Toadlets were placed in a supine position on a dry flat surface. Failure to right within 60 sec was considered as the loss of RR. The experiment was repeated 10 times. Control toadlets were pretreated with 90% ethanol instead of Nux Vomica 200 CH. The percentages of toadlets showing loss of RR, both in the control as well as in the Nux-treated groups, were shown in graphs against the duration of exposure to ethanol solution. Differences in the percentage distribution between the control and the treatment groups losing RR were tested by χ2 test. All the experiments were conducted at room temperature. The percentage of toadlets losing RR increased with time of exposure to ethanol solution. The increase was significantly higher with the control than with the Nux-treated group. Nux Vomica 200 CH might have influenced the mid-brain of toadlets thereby countering the hypnotic effect of ethanol in the toadlets.

  13. Bm-TFF2, a toad trefoil factor, promotes cell migration, survival and wound healing

    International Nuclear Information System (INIS)

    Research highlights: → Bm-TFF2 binds to epithelial cells and induces cell migration and wound healing. → Bm-TFF2 suppresses cell apoptosis. → Bm-TFF2 has no effect on cell proliferation. -- Abstract: Toad skin is naked and continually confronted by various injurious factors. Constant skin renewal and repairs occur frequently. However, the mechanisms of the renewal and repair have not clearly elucidated. In our previous work, a trefoil factor (TFF), Bm-TFF2, has been purified from the Bombina maxima skin and characterized as a platelet agonist. The mRNA of TFFs in toad skin was up-regulated greatly during the metamorphosis, indicating a pivotal role of TFFs in amphibian skin. Here, we presented the effects of Bm-TFF2 on the cell migration, apoptosis and proliferation. Bm-TFF2 bound to epithelial cells and showed strong cell motility activity. At the concentrations of 1-100 nM, Bm-TFF2-induced migration of human epithelial AGS and HT-29 cells, and rat intestinal epithelial IEC-6 cell lines. The in vitro wound healing assay also verified the activity of Bm-TFF2. Bm-TFF2 could also inhibit cell apoptosis induced by ceramide and sodium butyrate. The cell migration-promoting activity was abolished by MEK1 inhibitors, U0126 and PD98059, suggesting that ERK1/2 activation is crucial for Bm-TFF2 to stimulate cell migration. Taken together, Bm-TFF2 promoted wound healing by stimulating cell migration via MAPK pathway and preventing cell apoptosis. The potent biological activity of Bm-TFF2 makes it a useful molecular tool for further studies of structure-function relationship of the related human TFFs.

  14. Alfaxalone-butorphanol versus alfaxalone-morphine combination for immersion anaesthesia in oriental fire-bellied toads (Bombina orientalis).

    Science.gov (United States)

    Adami, Chiara; d'Ovidio, Dario; Casoni, Daniela

    2016-06-01

    Oriental fire-bellied toads (Bombina orientalis) are small semi-aquatic anuran species popular as both pets and laboratory animals. Although they are commonly anaesthetized to undergo clinical and experimental procedures, very little is known about their anaesthetic management. The aims of this prospective, randomized, cross-over experimental trial were to establish effective butorphanol and morphine concentrations to be added to alfaxalone for immersion anaesthesia (pilot study), and to compare the anaesthetic and antinociceptive effects of the two drug mixtures (alfaxalone-butorphanol and alfaxalone-morphine), in Bombina orientalis toads. For the actual trial, the toads were randomly assigned to one of two treatment groups: AB and AM, with seven animals in each group, which received alfaxalone-butorphanol and alfaxalone-morphine combinations, respectively, at the concentrations established during the pilot study. Heart rate, respiratory rate, von Frey filament threshold and response to nociceptive withdrawal (NWR), righting and myotactic reflexes were measured at 5 min intervals until return of righting reflex was observed. The investigator who carried out all the measurements was blinded to the treatment. Any undesired effect or complication was noted and recorded. The two treatments were found to be comparable in terms of onset and duration of anaesthesia, and occurrence of undesired effects. However, group AM resulted in lower NWR scores and higher von Frey filament thresholds than group AB. It is concluded that, at the investigated concentrations and in combination with alfaxalone by immersion, morphine provides better antinociception than butorphanol in oriental fire-bellied toads. PMID:26306614

  15. Checklist and Simple Identification Key for Frogs and Toads from District IV of The MADA Scheme, Kedah, Malaysia

    OpenAIRE

    Jaafar, Ibrahim; Chai, Teoh Chia; Sah, Shahrul Anuar Mohd; Akil, Mohd Abdul Muin Md.

    2009-01-01

    A survey was conducted to catalogue the diversity of anurans in District IV of the Muda Agriculture Development Authority Scheme (MADA) in Kedah Darul Aman, Malaysia, from July 1996 to January 1997. Eight species of anurans from three families were present in the study area. Of these, the Common Grass Frog (Fejevarya limnocharis) was the most abundant, followed by Mangrove Frog (Fejevarya cancrivora), Long-legged Frog (Hylarana macrodactyla), and Common Toad (Duttaphrynus melanostictus). Pudd...

  16. Lethal and sub-lethal effects on the Asian common toad Duttaphrynus melanostictus from exposure to hexavalent chromium.

    Science.gov (United States)

    Fernando, Vindhya A K; Weerasena, Jagathpriya; Lakraj, G Pemantha; Perera, Inoka C; Dangalle, Chandima D; Handunnetti, Shiroma; Premawansa, Sunil; Wijesinghe, Mayuri R

    2016-08-01

    Chromium discharged in industrial effluents frequently occurs as an environmental pollutant, but the lethal and sub-lethal effects the heavy metal might cause in animals exposed to it have been insufficiently investigated. Selecting the amphibian Duttaphrynus melanostictus, we carried out laboratory tests to investigate the effects of short and long term exposure to hexavalent chromium (Cr(VI)) in both tadpoles and adult toads. The concentrations used were 0.002, 0.02, 0.2, 1.0 and 2.0mg/L, the first three corresponding to field levels. In vitro exposures were also carried out using toad erythrocytes and Cr(VI) concentrations of 0.0015, 0.003, 0.015, 0.03, 0.15mg/L. Mortality, growth retardation, developmental delays and structural aberrations were noted in the metal-treated tadpoles, with increasing incidence corresponding to increase in Cr(VI) level and duration of exposure. Many of the sub-lethal effects were evident with long term exposure to environmentally relevant levels of the toxicant. Changes in selected blood parameters and erythrocyte morphometry were also detected in Cr(VI) exposed toads, indicating anaemic and leucopenic conditions. In the genotoxicity study, DNA damage indicated by comet assay and increased micronuclei frequency, occurred at the low Cr(VI) concentrations tested. The multiple deleterious effects of exposure to chromium signal the need for monitoring and controlling the discharge of chromium to the environment. The dose-dependency and genotoxic effects observed in this widely distributed Asian toad indicates its suitability for monitoring heavy metal pollution in aquatic systems. PMID:27262939

  17. Frogs in the spotlight: a 16-year survey of native frogs and invasive toads on a floodplain in tropical Australia.

    Science.gov (United States)

    Brown, Gregory P; Shine, Richard

    2016-07-01

    Although widespread declines in anuran populations have attracted considerable concern, the stochastic demographics of these animals make it difficult to detect consistent trends against a background of spatial and temporal variation. To identify long-term trends, we need datasets gathered over long time periods, especially from tropical areas where anuran biodiversity is highest. We conducted road surveys of four anurans in the Australian wet-dry tropics on 4637 nights over a 16-year period. Our surveys spanned the arrival of invasive cane toads (Rhinella marina), allowing us to assess the invader's impact on native anuran populations. Our counts demonstrate abrupt and asynchronous shifts in abundance and species composition from one year to the next, not clearly linked to rainfall patterns. Typically, periods of decline in numbers of a species were limited to 1-2 years and were followed by 1- to 2-year periods of increase. No taxa showed consistent declines over time, although trajectories for some species showed significant perturbations coincident with the arrival of toads. None of the four focal frog species was less common at the end of the study than at the beginning, and three of the species reached peak abundances after toad arrival. Survey counts of cane toads increased rapidly during the initial stage of invasion but have subsequently declined and fluctuated. Distinguishing consistent declines versus stochastic fluctuations in anuran populations requires extensive time-series analysis, coupled with an understanding of the shifts expected under local climatic conditions. This is especially pertinent when assessing impacts of specific perturbations such as invasive species. PMID:27386087

  18. Within- and among-population level differences in response to chronic copper exposure in southern toads, Anaxyrus terrestris

    International Nuclear Information System (INIS)

    Environmental contaminants are implicated in the global decline of amphibian populations. Copper (Cu) is a widespread contaminant that can be toxic at concentrations just above the normal physiological range. In the present study we examined the effects of chronic Cu aqueous exposure on embryos and larvae of southern toads, Anaxyrus (Bufo) terrestris. Measurable levels of Cu were found in larvae, with tissue concentrations up to 27.5 μg Cu/g dry mass. Aqueous concentrations of Cu as low as 10 μg/L significantly reduced survival to the free-swimming stage and no larvae reached metamorphosis at concentrations above 15 μg/L. Clutches from populations with prior Cu exposure had the lowest survivorship. Among several populations there was significant variation in survivorship at different levels of Cu. More data are needed to understand the underlying causes of within- and among-population resilience to anthropogenic stressors. -- Highlights: ► Southern toad, Anaxyrus terrestris, embryos and larvae are highly sensitive to Cu. ► Significant variation in survivorship exists among clutches and populations. ► Clutches with prior Cu exposure had the lowest survivorship. ► Body burdens in larvae were up to 27.5 μg Cu/g dry mass. -- Capsule: Southern toad aquatic survival is significantly reduced at 15 μg Cu/L with variation in survivorship across clutches and populations

  19. Survey of helminths, ectoparasites, and chytrid fungus of an introduced population of cane toads, Rhinella marina (Anura: Bufonidae), from Grenada

    Science.gov (United States)

    Drake, Michael C.; Zieger, Ulrike; Groszkowski, Andrew; Gallardo, Bruce; Sages, Patti; Reavis, Roslyn; Faircloth, Leslie; Jacobson, Krystin; Lonce, Nicholas; Pinckney, Rhonda D.; Cole, Rebecca Ann

    2014-01-01

    One hundred specimens of Rhinella marina, (Anura: Bufonidae) collected in St. George's parish, Grenada, from September 2010 to August 2011, were examined for the presence of ectoparasites and helminths. Ninety-five (95%) toads were parasitized by one or more parasite species. Nine species of parasites were found: 1 digenean, 2 acanthocephalans, 4 nematodes, 1 arthropod and 1 pentastome. The endoparasites represented 98.9% of the total number of parasite specimens collected. Grenada represents a new locality record for Mesocoelium monas, Raillietiella frenatus, Pseudoacanthacephalus sp., Aplectana sp., Physocephalus sp., Acanthacephala cystacanth and Physalopteridae larvae. The digenean M. monas occurred with the highest prevalence of 82%, contrasting many studies of R. marina where nematodes dominate the parasite infracommunity. Female toads were found to have a significantly higher prevalence of Amblyomma dissimile than male toads. Only two parasites exhibited a significant difference between wet and dry season with Parapharyngodon grenadensis prevalence highest in the wet season and A. dissimile prevalence highest during the dry season. Additionally, A. dissimile was significantly more abundant during the dry season.

  20. Effects of acute low temperature stress on the endocrine reactions of the Qinghai toad-headed lizard

    Institute of Scientific and Technical Information of China (English)

    Chunwang LI; Yuan GU; Songhua TANG; Hongxia FANG; Guohua JIANG; Zhigang JIANG

    2011-01-01

    Endocrinological action is generally thought to be a way for animals to respond to stress at low temperatures.To learn the role of hormones in eetotherms inhabiting alpine environments,we studied the effects of acute low temperature exposure on the endocrinological reactions of Qinghai toad-headed lizards in the Qinghai-Tibetan Plateau.We monitored plasma corticosterone and insulin concentration of the lizards under five low temperature treatments.We found no significant difference in plasma corticosterone or insulin in lizards among our five different treatments.For males and females the correlation between plasma corticosterone and insulin concentrations was not significant.In contrast to other studies on reptiles at low altitude,we suggest that due to the alpine environment (low temperature and low oxygen concentration) they inhabit,Qinghai toad-headed lizards respond to experimental cold stress slightly to mobilize energy and live their vivid life.In addition,corticosterone and insulin of Qinghai toad-headed lizards are secreted independently along with low temperature treatments [Current Zoology 57 (6):775-780,2011].

  1. El concilio Vaticano II y su impacto en el campo episcopal argentino The Second Vatican Council and its impact on argentinian Episcopal field

    Directory of Open Access Journals (Sweden)

    Paulo Margaria

    2012-06-01

    Full Text Available El presente artículo busca explorar el impacto que tuvo el Concilio Vaticano II en la Iglesia Católica Argentina, haciendo especial hincapié en el campo de los obispos, desde una perspectiva socio-religiosa que pretende dar cuenta de la complejidad del campo católico. Para ello nos parece adecuado utilizar la noción de "campo" en términos bourdianos. Consideramos que hablar de "campo religioso" nos permite concebir el catolicismo como un espacio social dinámico y atravesado por constantes conflictos y luchas llevadas a cabo por grupos de agentes que intentan dominar dicho campo. Esto nos permitirá caracterizar las diversas posturas que el Concilio acentuará en el catolicismo argentino, actuando de este modo como un propulsor y legitimador de reflexiones y conflictos que existían previamente.This article examines the impact that Second Vatican Council had on argentinian Catholic Church, with special emphasis on the Bishops field, from a socio-religious perspective that seeks to explain the complexity of Catholic field. Therefore, it seems appropriate to use the Pierre Bourdieu's notion of "field". We believe that talk about "religious field" allows us to conceive Catholicism as a dynamic social space spanned by constant conflicts and struggles carried out by groups of agents who tried to dominate the field. Again, this allows us to characterize the positions that the Council emphasized in the Argentine Catholicism, acting as a propellant and legitimizing ideas and conflicts that existed previously.

  2. A new species of flea-toad (Anura: Brachycephalidae) from southern Atlantic Forest, Brazil.

    Science.gov (United States)

    Condez, Thais Helena; Monteiro, Juliane Petry De Carli; Comitti, Estevão Jasper; Garcia, Paulo Christiano De Anchietta; Amaral, Ivan Borel; Haddad, Célio Fernando Baptista

    2016-01-01

    We describe a new species of Brachycephalus that is morphologically similar to the flea-toads B. didactylus, B. hermogenesi, and B. pulex. The new species occurs from the sea level up to 1000 m and it is widely distributed throughout southern Atlantic Forest. Brachycephalus sulfuratus sp. nov. is distinguished from all of its congeners by the combination of the following characters: (1) small body size (SVL of adults: 7.4-8.5 mm for males and 9.0-10.8 mm for females); (2) "leptodactyliform" body; (3) pectoral girdle arciferal and less robust compared to the Brachycephalus species with "bufoniform" body; (4) procoracoid and epicoracoid fused with coracoid but separated from the clavicle by a large fenestrae; (5) toe I externally absent; toes II, III, IV, and V distinct; phalanges of toes II and V reduced; (6) skin smooth with no dermal ossifications; (7) in life, general background color brown with small dark-brown spots; skin of throat, chest, arms, and forearms with irregular yellow blotches; in ventral view, cloacal region of alive and preserved specimens surrounded by a dark-brown inverted v-shaped mark outlined with white; (8) advertisement call long, composed of a set of 4-7 high-frequency notes (6.2-7.2 kHz) repeated regularly. PMID:27394218

  3. Effects of ADH on the apical and basolateral membranes of toad urinary bladder epithelial cells.

    Science.gov (United States)

    Donaldson, P J; Leader, J P

    1993-11-01

    Short-circuited urinary bladders from Bufo marinus were supported on their apical surface by an agar mounting method and impaled with microelectrodes via their basolateral membrane. This arrangement provided stable and long-lasting impalements of epithelial cells and yielded reliable membrane potentials and voltage divider ratios (Ra/Rb), where Ra and Rb are apical and basolateral membrane resistances respectively. The membrane potential under short-circuit conditions (Vsc) was -51.4 +/- 2.2 mV (n = 59), while under open-circuit conditions apical membrane potential (Va) and basolateral membrane potential (Vb) were -31.0 +/- 2.4 and 59.5 +/- 2.4 mV, respectively. This yields a "well-shaped" potential profile across the toad urinary bladder, where Va is inversely related to the rate of transport, Isc. Antidiuretic hormone (ADH) produced a hyperpolarisation of Vsc and Vb but had no significant effect on Va. In addition, Ra/Rb was significantly increased by ADH (4.6 +/- 0.5 to 10.2 +/- 3.6). Calculation of individual membrane resistances following the addition of amiloride showed that ADH produced a parallel decrease in Ra and Rb membrane resistance, with the observed increase in Ra/Rb being due to a greater percentage decrease in Rb than in Ra. The ability of ADH to effect parallel changes in apical and basolateral membrane conductance helps to maintain a constant cellular volume despite an increase in transepithelial transport. PMID:8309781

  4. Deep genetic structure and ecological divergence in a widespread human commensal toad.

    Science.gov (United States)

    Wogan, Guinevere O U; Stuart, Bryan L; Iskandar, Djoko T; McGuire, Jimmy A

    2016-01-01

    The Asian common toad (Duttaphrynus melanostictus) is a human commensal species that occupies a wide variety of habitats across tropical Southeast Asia. We test the hypothesis that genetic variation in D. melanostictus is weakly associated with geography owing to natural and human-mediated dispersal facilitated by its commensal nature. Phylogenetic and population genetic analyses of mitochondrial and nuclear DNA sequence variation, and predictive species distribution modelling, unexpectedly recovered three distinct evolutionary lineages that differ genetically and ecologically, corresponding to the Asian mainland, coastal Myanmar and the Sundaic islands. The persistence of these three divergent lineages, despite ample opportunities for recent human-mediated and geological dispersal, suggests that D. melanostictus actually consists of multiple species, each having narrower geographical ranges and ecological niches, and higher conservation value, than is currently recognized. These findings also have implications for the invasion potential of this human commensal elsewhere, such as in its recently introduced ranges on the islands of Borneo, Sulawesi, Seram and Madagascar. PMID:26763213

  5. Evolution of rapid development in spadefoot toads is unrelated to arid environments.

    Science.gov (United States)

    Zeng, Cen; Gomez-Mestre, Ivan; Wiens, John J

    2014-01-01

    The extent to which species' life histories evolve to match climatic conditions is a critical question in evolutionary biology and ecology and as human activities rapidly modify global climate. GIS-based climatic data offer new opportunities to rigorously test this question. Superficially, the spadefoot toads of North America (Scaphiopodidae) seem to offer a classic example of adaptive life-history evolution: some species occur in extremely dry deserts and have evolved the shortest aquatic larval periods known among anurans. However, the relationships between the climatic conditions where spadefoots occur and the relevant life-history traits have not been explicitly tested. Here, we analyzed these relationships using GIS-based climatic data, published life-history data, and a time-calibrated phylogeny for pelobatoid frogs. Surprisingly, we find no significant relationships between life-history variables and precipitation or aridity levels where these species occur. Instead, rapid development in pelobatoids is strongly related to their small genome sizes and to phylogeny. PMID:24800832

  6. Protein synthesis inhibitors attenuate water flow in vasopressin-stimulated toad urinary bladder

    International Nuclear Information System (INIS)

    Vasopressin stimulates the introduction of aggregated particles, which may represent pathways for water flow, into the luminal membrane of toad urinary bladder. It is not known whether water transport pathways are degraded on removal from membrane or whether they are recycled. The authors examined the effect of the protein synthesis inhibitors cycloheximide and puromycin using repeated 30-min cycles of vasopressin followed by washout of vasopressin, all in the presence of an osmotic gradient, a protocol that maximizes aggregate turnover. High dose cycloheximide inhibited flow immediately. Low dose cycloheximide did not affect initial flow. In the absence of vasopressin, inhibition did not develop. Despite the inhibition of flow in vasopressin-treated tissues, the cAMP-dependent protein kinase ratio was elevated in cycloheximide-treated tissues, suggesting modulation at a distal site in the stimulatory cascade. [14C]urea permeability was not inhibited by cycloheximide. Puromycin also inhibited water flow by the fourth challenge with vasopressin. The data suggest that protein synthesis inhibitors attenuate flow at a site that is distal to cAMP-dependent protein kinase. However, the reversal of inhibition in MIX-treated tissues suggests that the water pathway can be fully manifested given suitable stimulation. They conclude that either large stores of the transport system are available or that the transport system is extensively recycled on retrieval from the membrane

  7. Electron-microscopic study of the apical region of the toad bladder epithelial cell.

    Science.gov (United States)

    Sasaki, J; Tilles, S; Condeelis, J; Carboni, J; Meiteles, L; Franki, N; Bolon, R; Robertson, C; Hays, R M

    1984-09-01

    Antidiuretic hormone (ADH) promotes fusion of cytoplasmic tubules with the luminal membrane and delivery of particles from the tubules to the membrane. The particles are believed to be the water-conducting elements in the membrane. We have employed several scanning (SEM) and transmission electron-microscopic (TEM) techniques to study the relationship of the cytoplasmic tubules to the luminal membrane and to the apical cytoskeleton of the toad bladder epithelial cell. This paper reports the results of freeze-crack SEM and tannic acid-fixed TEM studies, as well as studies with a resinless method of embedding. Freeze-cracked epithelial cells reveal that the tubules are anchored in a matrix of cytoskeleton and granules just below the luminal membrane, and many, if not all, retain their anchorage to the matrix after ADH-induced fusion. Tannic acid-fixed specimens show that the tubules in unstimulated cells lie horizontally. Fusion appears to involve an angulation of the tubules, and this may be the major mode of ADH-induced tubule movement. There are suggestions in the tannic acid sections of filamentous attachments of tubules to the surrounding cytoskeleton. In addition there are prominent microfilament bundles running down the microvilli and a dense concentration of filaments just below the luminal membrane. The presence of these filaments is confirmed in the resinless sections, and their possible role in ADH action is discussed. PMID:6433717

  8. Genomewide scan for adaptive differentiation along altitudinal gradient in the Andrew's toad Bufo andrewsi.

    Science.gov (United States)

    Guo, Baocheng; Lu, Di; Liao, Wen Bo; Merilä, Juha

    2016-08-01

    Recent studies of humans, dogs and rodents have started to discover the genetic underpinnings of high altitude adaptations, yet amphibians have received little attention in this respect. To identify possible signatures of adaptation to altitude, we performed a genome scan of 15 557 single nucleotide polymorphisms (SNPs) obtained with restriction site-associated DNA sequencing of pooled samples from 11 populations of Andrew's toad (Bufo andrewsi) from the edge of the Tibetan Plateau, spanning an altitudinal gradient from 1690 to 2768 m.a.s.l. We discovered significant geographic differentiation among all sites, with an average FST   = 0.023 across all SNPs. Apart from clear patterns of isolation by distance, we discovered numerous outlier SNPs showing strong associations with variation in altitude (1394 SNPs), average annual temperature (1859 SNPs) or both (1051 SNPs). Levels and patterns of genetic differentiation in these SNPs were consistent with the hypothesis that they have been subject to directional selection and reflect adaptation to altitudinal variation among the study sites. Genes with footprints of selection were significantly enriched in binding and metabolic processes. Several genes potentially related to high altitude adaptation were identified, although the identity and functional significance of most genomic targets of selection remain unknown. In general, the results provide genomic support for results of earlier common garden and low coverage genetic studies that have uncovered substantial adaptive differentiation along altitudinal and latitudinal gradients in amphibians. PMID:27289071

  9. Phylogeography and demography of Guianan harlequin toads (Atelopus): diversification within a refuge.

    Science.gov (United States)

    Noonan, Brice P; Gaucher, Philippe

    2005-09-01

    We investigated the genetic structure of populations of Guianan harlequin toads (genus Atelopus) and their evolutionary affinities to extra-Guianan congeners. Phylogenetic analysis of mitochondrial cytochrome b (cyt b) and NADH dehydrogenase subunit 2 (ND2) gene sequences produced well-supported clades largely corresponding to the four recognized taxa in the Guianas (Atelopus spumarius hoogmoedi, Atelopus spumarius barbotini, Atelopus franciscus, and Atelopus flavescens). Our findings suggest that the Guianan A. spumarius represent distinct evolutionary lineages that merit distinction from Amazonian conspecifics, and that the status of A. flavescens and A. franciscus is somewhat less clear. Approximately 69% of the observed genetic variation is accounted for by differences between these four recognized taxa. Coalescent-based estimates of gene flow between taxa suggest that these lineages are largely isolated from one another. Negligible rates of migration between populations and significant divergence within such close proximity suggests that although the region inhabited by these taxa is almost entirely undisturbed, significant habitat heterogeneity exists as to have produced a remarkable diversification of Atelopus within the eastern Guiana Shield. These results contradict the commonly held view of the Guiana Shield as a 'refuge' whose stability during late Tertiary and Quaternary climatic fluctuations served as a biotic reservoir. Instead, we provide evidence that climatic fluctuations during this time had a diversifying effect within the Guianan region. PMID:16101771

  10. Variety of antimicrobial peptides in the Bombina maxima toad and evidence of their rapid diversification.

    Science.gov (United States)

    Lee, Wen-Hui; Li, Yan; Lai, Ren; Li, Sha; Zhang, Yun; Wang, Wen

    2005-04-01

    Antimicrobial peptides secreted by the skin of many amphibians play an important role in innate immunity. From two skin cDNA libraries of two individuals of the Chinese red belly toad (Bombina maxima), we identified 56 different antimicrobial peptide cDNA sequences, each of which encodes a precursor peptide that can give rise to two kinds of antimicrobial peptides, maximin and maximin H. Among these cDNA, we found that the mean number of nucleotide substitution per non-synonymous site in both the maximin and maximin H domains significantly exceed the mean number of nucleotide substitution per synonymous site, whereas the same pattern was not observed in other structural regions, such as the signal and propiece peptide regions, suggesting that these antimicrobial peptide genes have been experiencing rapid diversification driven by Darwinian selection. We cloned and sequenced seven genes amplified from skin or liver genomic DNA. These genes have three exons and share the same gene structure, in which both maximin and maximin H are encoded by the third exon. This suggests that alternative splicing and somatic recombination are less likely to play a role in creating the diversity of maximins and maximin Hs. The gene trees based on different domain regions revealed that domain shuffling or gene conversion among these genes might have happened frequently. PMID:15770703

  11. Maximins S, a novel group of antimicrobial peptides from toad Bombina maxima.

    Science.gov (United States)

    Wang, Ting; Zhang, Jie; Shen, Ji-Hong; Jin, Yang; Lee, Wen-Hui; Zhang, Yun

    2005-02-18

    Amphibian skin secretions are rich in antimicrobial peptides acting as important components of innate defense system against invading microorganisms. A novel type of peptide, designated as maximin S, was deduced by random sequencing of 793 clones from a constructed Bombina maxima skin cDNA library. The putative primary structures of maximin S peptides can be grouped into five species, in which maximin S1 has 14 amino acid residues and the rest of maximin S peptides (S2-S5) all have 18 amino acid residues. Unlike most of the amphibian antimicrobial peptides so far identified, the newly characterized four maximin S precursors are composed of maximin S1 and different combinations of tandem repeated maximin S2-S5 linked by internal peptides. Except maximin S1, the predicted secondary structures of maximin S2-S5 show a similar amphipathic alpha-helical structure. MALDI-TOF mass spectrometry analysis of partially isolated skin secretions of the toad indicates that most of the deduced maximin S peptides are expressed. Two deduced maximin S peptides (S1, S4) were synthesized and their antimicrobial activities were tested. Maximin S4 only had an antibiotic activity against mycoplasma and had no antibacterial or antifungal activity toward tested strains. Maximin S1 had no activity under the same conditions. PMID:15649437

  12. keratinized nuptial spines are used for male combat in the emei moustache toad (leptobrachium boringii)

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    we describe the natural history and reproductive behaviour of the emei moustache toad (leptobrachium boringii)with an emphasis on the development of keratinized nuptial spines in males and document combat behaviour for the first time in this species.between february and march of 2011,19 female and 43 male l.boringii from mount emei unesco world heritage site,sichuan,china were observed throughout the breeding season.this species exhibits male-biased sexual size dimorphism (ssd)with limited evidence of paternal care (nest guarding by males).prior to the breeding season males grow 10-16 keratinized spines on their upper lip,which fall off once the season has ended.throughout the breeding season males construct and defend aquatic nests where they produce advertisement calls to attract females.during this time we documented 14 cases involving a total of 22 males where males used their moustaches for aggressive interaction.combat typically occurred at the beginning of the season when males would compete for a limited number of available nest sites.neither male body size,nor body condition significantly affects the outcome of an aggressive interaction,suggesting that size may not be the only factor influencing an individual's chance of victory.our evidence for male competition and aggression,along with observed paternal care are potential mechanisms to explain the evolution of male-biased ssd observed in this species.

  13. Analysis of heart rate control to assess thermal sensitivity responses in Brazilian toads

    Directory of Open Access Journals (Sweden)

    J.E.S. Natali

    2015-01-01

    Full Text Available In anurans, changes in ambient temperature influence body temperature and, therefore, energy consumption. These changes ultimately affect energy supply and, consequently, heart rate (HR. Typically, anurans living in different thermal environments have different thermal sensitivities, and these cannot be distinguished by changes in HR. We hypothesized that Rhinella jimi (a toad from a xeric environment that lives in a wide range of temperatures would have a lower thermal sensitivity regarding cardiac control than R. icterica (originally from a tropical forest environment with a more restricted range of ambient temperatures. Thermal sensitivity was assessed by comparing animals housed at 15° and 25°C. Cardiac control was estimated by heart rate variability (HRV and heart rate complexity (HRC. Differences in HRV between the two temperatures were not significant (P=0.214 for R. icterica and P=0.328 for R. jimi, whereas HRC differences were. All specimens but one R. jimi had a lower HRC at 15°C (all P<0.01. These results indicate that R. jimi has a lower thermal sensitivity and that cardiac control is not completely dependent on the thermal environment because HRC was not consistently different between temperatures in all R. jimi specimens. This result indicates a lack of evolutive trade-offs among temperatures given that heart rate control at 25°C is potentially not a constraint to heart rate control at 15°C.

  14. Analysis of heart rate control to assess thermal sensitivity responses in Brazilian toads.

    Science.gov (United States)

    Natali, J E S; Santos, B T; Rodrigues, V H; Chauí-Berlinck, J G

    2015-01-01

    In anurans, changes in ambient temperature influence body temperature and, therefore, energy consumption. These changes ultimately affect energy supply and, consequently, heart rate (HR). Typically, anurans living in different thermal environments have different thermal sensitivities, and these cannot be distinguished by changes in HR. We hypothesized that Rhinella jimi (a toad from a xeric environment that lives in a wide range of temperatures) would have a lower thermal sensitivity regarding cardiac control than R. icterica (originally from a tropical forest environment with a more restricted range of ambient temperatures). Thermal sensitivity was assessed by comparing animals housed at 15° and 25°C. Cardiac control was estimated by heart rate variability (HRV) and heart rate complexity (HRC). Differences in HRV between the two temperatures were not significant (P=0.214 for R. icterica and P=0.328 for R. jimi), whereas HRC differences were. All specimens but one R. jimi had a lower HRC at 15°C (all Ptemperatures in all R. jimi specimens. This result indicates a lack of evolutive trade-offs among temperatures given that heart rate control at 25°C is potentially not a constraint to heart rate control at 15°C. PMID:25493382

  15. Ultrastructural and Molecular Changes in the Developing Small Intestine of the Toad Bufo regularis

    Directory of Open Access Journals (Sweden)

    S. A. Sakr

    2014-01-01

    Full Text Available The ontogenetic development of the small intestine of the toad Bufo regularis was investigated using twofold approaches, namely, ultrastructural and molecular. The former has been done using transmission electron microscope and utilizing the developmental stages 42, 50, 55, 60, 63, and 66. The most prominent ultrastructural changes were recorded at stage 60 and were more evident at stage 63. These included the appearance of apoptotic bodies/nuclei within the larval epithelium, the presence of macrophages, swollen mitochondria, distorted rough endoplasmic reticulum, chromatin condensation, and irregular nuclear envelop, and the presence of large vacuoles and lysosomes. The molecular investigation involved examining DNA content and fragmentation. The results showed that the DNA content decreased significantly during the metamorphic stages 60 and 63 compared with both larval (50 and 55 and postmetamorphic (66 stages. The metamorphic stages (60 and 63 displayed extensive DNA laddering compared with stages 50, 55, and 66. The percentage of DNA damage was 0.00%, 12.91%, 57.26%, 45.48%, and 4.43% for the developmental stages 50, 55, 60, 63, and 66, respectively. In conclusion, the recorded remodeling of the small intestine represents a model for clarifying the mechanism whereby cell death and proliferation are controlled.

  16. Sexual dimorphism in baseline urinary corticosterone metabolites and their association with body-condition indices in a peri-urban population of the common Asian toad (Duttaphrynus melanostictus).

    Science.gov (United States)

    Narayan, Edward J; Gramapurohit, Narahari P

    2016-01-01

    Field endocrinology research through the quantification of glucocorticoids or stress hormones in free-living wildlife is crucial for assessing their physiological responses towards pervasive environmental changes. Urinary corticosterone metabolite (UCM) enzyme-immunoassay (EIA) has been validated for numerous amphibian species as a non-invasive measure of physiological stress. Body-condition indices (BCIs) have also been widely used in amphibians as an indirect measure of animal health. Field endocrinology research on amphibian species in Asia is limited. In this study, we validated a UCM EIA in a peri-urban sub-population of the common Asian toad (Duttaphrynus melanostictus) in Pune, Maharashtra, India. We determined the baseline levels of UCMs in male (n=39) and female (n=19) toads. Secondly, we used a standard capture handling protocol to quantify changes in UCMs during short-term captivity. We also determined BCIs in the male and female toads using Fulton's index (K) and residual condition index (RCI). The results showed that mean baseline levels of UCMs were significantly higher in male toads than in females. There was no significant change in mean levels of UCMs of males and females between capture and captivity (0-12h). This highlights plausible habituation of the species to the peri-urban environment. Associations between UCMs with BCIs (K and R) were positive in male toads but negative in females. In conclusion, our UCMs EIA can be applied with BCIs to assess health of the Asian toads. We also suggest that direct fitness parameters such as sperm and oocyte quality, reproductive ecology and immunocompetence measurements should be applied in combination with these conservation physiology tools to quantify the fitness consequences of pervasive environmental changes on native amphibians. PMID:26478192

  17. The influence of ambient salinity and temperature on lipid metabolism in toad (Bufo bufo) skin. Is phosphatidylethanolamine an endogenous regulator of ion channels?

    DEFF Research Database (Denmark)

    Hansen, H.J.M.; Olsen, Allan Gylling; Willumsen, Niels J.

    1994-01-01

    transepithelial electrical potential in vitro. While all the incorporations in vitro showed (32P) and (14C) frog and toad skin phospholipid patterns dominated by phosphatidylcholine-independent of adaptational temperature and salinity--corresponding phospholipid patterns dominated by phosphatidylethanolamine (PE......Incorporation of (32P) phosphate and (14C) acetate into frog (Rana temporaria) skin phospholipids in vitro was positively correlated to skin MR cell density. Transport across toad (Bufo bufo) skin and incorporation into skin phospholipids of the radioactive tracers were independent of...

  18. Patterns of Genetic Variability in Island Populations of the Cane Toad (Rhinella marina) from the Mouth of the Amazon

    Science.gov (United States)

    Bessa-Silva, Adam Rick; Vallinoto, Marcelo; Sodré, Davidson; da Cunha, Divino Bruno; Hadad, Dante; Asp, Nils Edvin; Sampaio, Iracilda; Schneider, Horacio; Sequeira, Fernando

    2016-01-01

    The Amazonian coast has several unique geological characteristics resulting from the interaction between drainage pattern of the Amazon River and the Atlantic Ocean. It is one of the most extensive and sedimentologically dynamic regions of the world, with a large number of continental islands mostly formed less than 10,000 years ago. The natural distribution of the cane toad (Rhinella marina), one of the world’s most successful invasive species, in this complex Amazonian system provides an intriguing model for the investigation of the effects of isolation or the combined effects of isolation and habitat dynamic changes on patterns of genetic variability and population differentiation. We used nine fast-evolving microsatellite loci to contrast patterns of genetic variability in six coastal (three mainlands and three islands) populations of the cane toad near the mouth of the Amazon River. Results from Bayesian multilocus clustering approach and Discriminant Analyses of Principal Component were congruent in showing that each island population was genetically differentiated from the mainland populations. All FST values obtained from all pairwise comparisons were significant, ranging from 0.048 to 0.186. Estimates of both recent and historical gene flow were not significantly different from zero across all population pairs, except the two mainland populations inhabiting continuous habitats. Patterns of population differentiation, with a high level of population substructure and absence/restricted gene flow, suggested that island populations of R. marina are likely isolated since the Holocene sea-level rise. However, considering the similar levels of genetic variability found in both island and mainland populations, it is reliable to assume that they were also isolated for longer periods. Given the genetic uniqueness of each cane toad population, together with the high natural vulnerability of the coastal regions and intense human pressures, we suggest that these

  19. Breeding pond selection and movement patterns by eastern spadefoot toads (Scaphiopus holbrookii) in relation to weather and edaphic conditions.

    Energy Technology Data Exchange (ETDEWEB)

    Greenberg, Cathryn H. [USDA Forest Service, New Ellenton, SC (United States); Tanner, George W. [USDA Forest Service, New Ellenton, SC (United States)

    2004-08-31

    Cathryn H. Greenberg and George W. Tanner. 2004. Breeding pond selection and movement patterns by eastern spadefoot toads (Scaphiopus holbrookii) in relation to weather and edaphic conditions. J. Herp. 38(4):569-577. Abstract: Eastern Spadefoot Toads (Scaphiopus holbrookii) require fish-free, isolated, ephemeral ponds for breeding but otherwise inhabit the surrounding uplands, commonly xeric longleaf pine (Pinus palustris) wiregrass (Aristida beyrichiana). Hence both pond and upland conditions can potentially affect their breeding biology, and population persistence. Hardwood invasion due to fire suppression in sandhills could alter upland and pond suitability by higher hardwood density and increased transpiration. In this paper we explore breeding and neonatal emigration movements in relation to weather, hydrological conditions of ponds, and surrounding upland matrices. We use 9 years of data from continuous monitoring with drift fences and pitfall traps at 8 ephemeral ponds in 2 upland matrices: regularly-burned, savanna-like sandhills (n = 4), and hardwood-invaded sandhills (n = 4). Neither adult nor neonate captures differed between ponds within the 2 upland matrices, suggesting that they are tolerant of upland heterogeneity created by fire frequency. Explosive breeding occurred during 9 periods and in all seasons; adults were captured rarely otherwise. At a landscape-level rainfall, maximum change in barometric pressure, and an interaction between those 2 variables were significant predictors of explosive breeding. At a pond-level, rainfall, change in pond depth during the month prior to breeding, and days since a pond was last dry were significant predictors of adult captures. Transformation date, rather than weather, was associated with neonatal emigrations, which usually were complete within a week. Movement by first-captured adults and neonates was directional, but adult emigrations were apparently not always toward their origin. Our results suggest that

  20. Relation between chloride exchange diffusion and a conductive chloride pathway across the isolated skin of the toad (Bufo bufo)

    DEFF Research Database (Denmark)

    Kristensen, P; Larsen, Erik Hviid

    1978-01-01

    Substitution of chloride in the outside bathing medium of the toad skin with bromide, iodide, nitrate and sulphate leads to a reduction in the apparent exchange diffusion of chloride across this tissue, and also to a reduction of the chloride current recorded during hyperpolarization. A series of...... systems could be explained as secondary effects due to a primary interaction with the sodium transport mechanisms. A correlation was found between the clamping current recorded during hyperpolarization and the efflux of chloride under short circuit conditions with chloride Ringer's on both sides. On the...

  1. The dynamics of venous return and response to hypervolemia in the toad, Bufo marinus (L.

    Directory of Open Access Journals (Sweden)

    Toews Daniel P

    2001-10-01

    Full Text Available Abstract Background Venous return from the posterior region of amphibians travels by either two renal portal veins to the kidney or a central abdominal vein that drains into the hepatic portal system. The relative proportions of blood flow in these vessels has never been measured nor has a modification of flow been determined when venous return increases by changes in blood volume during hypervolemia or during increased volume input from the posterior lymph hearts. Results Venous return from the posterior region of Bufo marinus was measured under resting conditions and in response to a systemic hypervolemia. Doppler flow probes were positioned on the renal portal and ventral abdominal veins, and flow was recorded as injections of artificial plasma equaling 100% of the animal's plasma volume were administered through the sciatic artery. Resting flow was found to be 5.54 ± 2.03 ml min-1 kg-1 in the paired renal portal veins, and 7.31 ± 0.89 ml min-1 kg-1 in the ventral abdominal vein. While renal portal flow was found to increase by a factor of 2.4 times during the first 10 min of hypervolemia, ventral abdominal flow only increased by a factor of 1.3. Conclusions Our results quantify the contribution to circulation from posterior venous return in the toad Bufo marinus. A preferential movement of excess fluid through the renal portal pathway was also demonstrated, supporting the possibility of water elimination via the renal portal circulation, especially during periods of high water influx into the animals.

  2. Malformations and mortality in the Asian Common Toad induced by exposure to pleurolophocercous cercariae (Trematoda: Cryptogonimidae).

    Science.gov (United States)

    Jayawardena, Uthpala A; Tkach, Vasyl V; Navaratne, Ayanthi N; Amerasinghe, Priyanie H; Rajakaruna, Rupika S

    2013-06-01

    Malformations and increased mortality due to infection by the digenetic trematode, Riberioa ondatrae have been reported for many species of amphibians. Severe malformations have also been reported in the Common Hourglass Tree Frog, Polypedates cruciger induced by pleurolophocercous cercariae in Sri Lanka in addition to the changes in the behaviour, development and survival of the host. We exposed pre-limb bud stage tadpoles (Gosner stages 25-26) of the Asian Common Toad, Duttaphrynus melanostictus to the same pleurolophocercous type cercariae under laboratory conditions. Molecular and morphological identification showed that these cercariae belonged Acanthostomum burminis infecting freshwater snakes as definitive hosts. These cercariae induced malformations (27.8%) and reduced survival to metamorphosis (53.8%). The magnitude of the effects increased with the dose of cercariae. Types of malformations were mainly axial, such as scoliosis and kyphosis. Severe limb malformations such as extra or missing limbs as reported for amphibians exposed to R. ondatrae were not observed in the D. melanostictus. Same authors reported a higher percentage of malformations previously when P. cruciger was exposed to the cercariae A. burminis compared to D. melanostictus. However, tadpoles of D. melanostictus, which are smaller compared to those of P. cruciger, experienced higher mortality than P. cruciger tadpoles. Trematode induced malformations and mortality in amphibians are highly variable and depend on multiple factors such as host species differences such as resistance to infection and tolerance, life-history characteristics such as size at metamorphosis and length of the metamorphosis period, and other factors such as size of the amphibian at the time of trematode exposure. PMID:23353759

  3. Spatial and temporal ecology of eastern spadefoot toads on a Florida landscape.

    Energy Technology Data Exchange (ETDEWEB)

    Greenberg, Cathyrn, H.; Tanner, George, W.

    2005-03-01

    Effective amphibian conservation must consider population and landscape processes, but information at multiple scales is rare. We explore spatial and temporal patterns of breeding and recruitment by Eastern Spadefoot Toads (Scaphiopus holbrookii), using 9 years of data from continuous monitoring with drift fences and pitfall traps at 8 ephemeral ponds in longleaf pine-wiregrass sandhills. Breeding events (>25 adults at a pond within a month) occurred 23 times on nine occasions at seven of the eight study ponds, but substantial recruitment(>100 metamorphs) followed only five events. Recruitment ranged from 0-4,648 among ponds. Only four ponds functioned as population ''sources'', but only during some years. The other ponds, and even ''source'' ponds during some years, functioned either as ''sinks'', where breeding occurred with no resulting recruitment, or were not used at all for breeding. Most recruitment occurred during four years. Recruitment was correlated with adult breeding effort, but only during some years. Recaptures were rare, and inter-pond exchange of adults was minimal and short-distance (< 130 m; 1 was 416 m). Most (83.5%) individuals captured were metamorphs, and 15.9% were > 51 mm (est. > 4 years). We conservatively estimated a 7-year lifespan. Adult ''population'' trends clearly reflected breeding effort rather than numbers per se; capture rates fluctuated dramatically among years, but showed no overall trends during the 9-year study. Our paper provides empiracle information that can be used to generate realistic metapopulation models for S. holbrookii as a tool in conservation planning.

  4. Microsatellite analysis of the natterjack toad ( Bufo calamita ) in Denmark: populations are islands in a fragmented landscape

    DEFF Research Database (Denmark)

    Allentoft, Morten E.; Siegismund, Hans Redlef; Briggs, Lars; Andersen, Liselotte Wesley

    2009-01-01

    The European natterjack toad (Bufo calamita) has declined rapidly in recent years, primarily due to loss of habitat, and in Denmark it is estimated that 50% of the isolated populations are lost each decade. To efficiently manage and conserve this species and its genetic diversity, knowledge of the...

  5. Possible differences in pathogenicity between cane toad-, frog- and platypus-derived isolates of Mucor amphibiorum, and a platypus-derived isolate of Mucor circinelloides.

    Science.gov (United States)

    Stewart, N J; Munday, B L

    2005-03-01

    Platypuses (Ornithorhynchus anatinus) in the north of the island state of Tasmania, Australia, suffer from a serious disease called ulcerative mycosis, which is responsible for high morbidity and, presumably, mortality rates in areas where it occurs. The disease is caused by the dimorphic fungus Mucor amphibiorum, which is also found in Queensland, New South Wales and Victoria. However, it does not cause disease in platypuses in those states. It has been previously reported that a closely related fungus, Mucor circinelloides, may also be capable of causing this disease. This paper describes pathogenicity trials involving cane toads (Bufo marinus) as the experimental model. The toads were infected with either Tasmanian, platypus-derived M. amphibiorum, West Australian, frog-derived M. amphibiorum, Queensland cane-toad-derived M. amphibiorum or Tasmanian platypus-derived M. circinelloides. The Tasmanian isolates of M. amphibiorum were more likely to cause a serious, long-term infection than were Queensland or West Australian isolates, and (+) mating types caused a more serious infection than the (-) mating type. The isolate of M. circinelloides was incapable of infecting the toads, lending further weight to the theory that it represents an environmental contaminant. The results suggest that an endemic strain of M. amphibiorum has mutated and become pathogenic to platypuses. Alternatively, a pathogenic strain of M. amphibiorum may have been introduced into Tasmania, where it is infecting a naïve population. PMID:15832556

  6. Spitzer Observations of Var Her 04: Possible Detection of Dust Formation in a Super-Outbursting TOAD

    CERN Document Server

    Ciardi, D R; Hoard, D W; Howell, S B; Van Belle, G T; Ciardi, David R.; Wachter, Stefanie; Howell, Steve B.; Belle, Gerard T. van

    2006-01-01

    We present four MIPS (24 \\micron) and two IRAC (3.6, 4.5, 5.8, and 8.0 \\micron) Spitzer observations of the newly discovered Tremendous Outburst Amplitude Dwarf nova (TOAD) Var Her 04 during decline from super-outburst. The four MIPS observations span 271 days and the two IRAC observations span 211 days. Along the line-of-sight to Var Her 04, there is a foreground M-star within 1\\arcsec of the variable; as a result, all of the Spitzer photometry presented in this paper is a blend of the foreground M-star and Var Her 04. We estimate the quiescent level of the TOAD to be $\\Delta V=4-5$ magnitudes below that of the M-star. Based upon the spectral energy distribution and the 2MASS colors, we find the M-star to be an M3.5V dwarf at a distance of 80-130 pc. Based upon its outburst amplitude and quiescent apparent magnitude, we estimate the distance to Var Her 04 to be 200-400 pc, suggesting that the line-of-sight foreground star is physically unrelated to the cataclysmic variable. All of the Spitzer photometry is c...

  7. AVALIATION OF VENTILATORY PATTERN IN THE TOAD RHINELLA SCHNEIDERI (ANURA: BUFONIDAE

    Directory of Open Access Journals (Sweden)

    FERNANDES, Marcelo dos Santos

    2010-11-01

    Full Text Available Amphibians ventilated their lungs by buccal pumping mechanism, which was first described in 1969 as a model for studying anurans respiration. Since amphibians do not have alveoli in their lungs, wecalculated to the toad Rhinella schneideri the equivalent lung ventilation from the equation VEFF = (VLCO2·RT/PLCO2. We analyzed buccal and pulmonary pressures, respiratory volumes, lung and buccalventilation, and ventilation frequency. [VE (12,1 ± 0,6ml BTPS.min-1.kg-1 ; VEB (164,3 ± 2,2ml BTPS.min-1.kg- 1 ; fR (5,8 ± 0,4min-1; buccal frequencies (68,5 ± 1,6min-1; Tidal volume(VT = 2.4 ml BTPS·kg-1]. The low oxygen extraction (17,3 ± 2,8% was used to explain the high frequency of pulmonary and buccal ventilation.Os anfíbios ventilam seus pulmões por meio de bombeamento bucal, mecanismo que foi primeiramente descrito 1969 como um modelo para a respiração de anuros. Como os anfíbios não possuem alvéolos em seus pulmões, foi calculado para o sapo Rhinella schneideri a ventilação equivalente do pulmão por meio da equação VEFF = (VLCO2·RT/PLCO2. Analisamos as pressões bucais e pulmonares, os volumes respiratórios, ventilação pulmonar e bucal, e frequências de ventilação. [VE (12,1 ± 0,6 ml BTPS.min-1.kg-1; VEB (164,3 ± 2,2 ml BTPS.min-1.kg-1; fR (5,8 ± 0,4 min -1; Freqüência bucal (68,5 ± 1,6 min-1; volume corrente(VT = 2,4 BTPS ml • kg-1]. A baixa extração de oxigênio (17,3% ± 2,8 foi utilizada para explicar a alta freqüência da ventilação pulmonar e bucal.

  8. Cyclic AMP-and beta-agonist-activated chloride conductance of a toad skin epithelium.

    Science.gov (United States)

    Willumsen, N J; Vestergaard, L; Larsen, E H

    1992-04-01

    1. The control by intracellular cyclic AMP and beta-adrenergic stimulation of chloride conductance was studied in toad skin epithelium mounted in a chamber on the stage of an upright microscope. Impalement of identified principal cells from the serosal side with single-barrelled conventional or double-barrelled Cl(-)-sensitive microelectrodes was performed at x500 magnification. For blocking the active sodium current 50 microM-amiloride was present in the mucosal bath. 2. When clamped at transepithelial potential difference V = 0 mV, the preparations generated clamping currents of 0.9 +/- 1 microA/cm2 (mean +/- S.E.M.; number of observations n = 55). The intracellular potential of principal cells (Vb) was -96 +/- 2 mV with a fractional resistance of the basolateral membrane (fRb) of 0.016 +/- 0.003 (n = 54), and an intracellular Cl- activity of 40 +/- 2 mM (n = 24). 3. At V = 0 mV, serosal application of a cyclic AMP analogue, dibutyryl cyclic AMP (500 microM) or a beta-adrenergic agonist, isoprenaline (5 microM) resulted in a sixfold increase in transepithelial Cl- conductance identified by standard 36Cl- tracer technique. 4. The clamping current at V = 0 mV was unaffected by cyclic AMP (short-circuit current Isc = 0.1 +/- 0.3 microA/cm2, n = 16) indicating that subepidermal Cl(-)-secreting glands are not functioning in our preparations obtained by collagenase treatment. 5. Cyclic AMP- or isoprenaline-induced chloride conductance (Gcl) activation (V = 0 mV) was not reflected in membrane potential and intracellular Cl- activity in principal cells. Intracellular chloride activity was constant at approximately 40 mM at membrane potentials between -90 and -100 mV. Therefore, it can be concluded that the principal cells are not contributing to activated Cl- currents. 6. At V = -100 mV where the voltage-dependent chloride conductance of mitochondria-rich (MR) cells was already fully activated, GCl was unaffected by cyclic AMP or isoprenaline. The major effect of these

  9. Delimiting genetic units in Neotropical toads under incomplete lineage sorting and hybridization

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    Thomé Maria Tereza C

    2012-12-01

    Full Text Available Abstract Background Delimiting genetic units is useful to enhance taxonomic discovery and is often the first step toward understanding evolutionary mechanisms generating diversification. The six species within the Rhinella crucifer group of toads were defined under morphological criteria alone. Previous data suggest limited correspondence of these species to mitochondrial lineages, and morphological intergradation at transitions between forms suggests hybridization. Here we extensively sampled populations throughout the geographic distribution of the group and analyzed mitochondrial and nuclear sequence data to delimit genetic units using tree–based and allele frequency–based approaches. Results These approaches yielded complementary results, with allele frequency-based methods performing unexpectedly well given the limited number of loci examined. Both mitochondrial and nuclear markers supported a genetic structure of five units within the group, with three of the inferred units distributed within its main range, while two other units occur in separate isolates. The inferred units are mostly discordant with currently described forms: unequivocal association exists for only two of the six species in the group. Genetic evidence for hybridization exists for two pairs of units, with clear cyto–nuclear allele mixing observed in one case. Conclusions Our results confirmed that current taxonomy does not represent evolutionary units in the Rhinella crucifer group. Correspondence between genetically distinguishable units and the currently recognized species is only possible for Rhinella henseli and R. inopina. The recognition of other species relies on the reassessment of the geographic range of R. crucifer, the examination of the type series of R. ornata for hybrids, and on the use of additional markers to verify the genetic distinctiveness of R. abei. We state that R. pombali should not remain a valid species since its description appears to be

  10. A new species of Paracapillaria (Nematoda: Capillariidae) from the intestine of the toad Duttaphrynus melanostictus (Anura) from the Malayan Peninsula.

    Science.gov (United States)

    Moravec, Frantisek; Modrý, David; Jirků, Miloslav

    2007-08-01

    A new species of parasitic nematode, Paracapillaria malayensis n. sp. (Capillariidae), is described from the small intestine of the toad Duttaphrynus melanostictus imported from the Malayan Peninsula to the Czech Republic. The new species differs from the only other congeneric species, Paracapillaria spratti, mainly in the shape and structure of the spicular proximal end (with a lobular rim), smaller eggs (45-51 x 21-24 microm), longer spicule (336 microm), and the number (37-38) of stichocytes in gravid females; whereas P. spratti parasitizes frogs of the Microhylidae in Papua New Guinea, P. malayensis is a parasite of Bufonidae in the Malayan Peninsula. Other Paracapillaria spp. are parasites of fishes, birds, or mammals and they mostly differ from P. malayensis in the structure of eggs and some other morphological features. PMID:17918374

  11. Immunohistochemical localization of cathepsin D and a possible role of melanocytes during tail resorption in tadpoles of a tropical toad.

    Science.gov (United States)

    Mahapatra, Cuckoo; Mahapatra, Pravati Kumari

    2012-07-01

    Programmed cell death during anuran tail resorption is primarily brought about by apoptosis. Cathepsin D, a lysosomal aspartyl protease, is involved in the death of tail tissues. Thus, anuran tail resorption presents an ideal model to study cathepsin-mediated cell death during vertebrate development. Present study describes the trend of specific activity of cathepsin D in the tail of different developmental stages and immunohistochemical localization of cathepsin D in the tail tissues of the common Asian toad, Duttaphrynus melanostictus. Cathepsin D was involved in programmed cell death in epidermis, muscle, spinal cord, and blood cells in the resorbing tail. Interestingly, it was also involved in the pre-resorbing tail before visible tail resorption which indicates initiation of cell death even before actually the tail resorbs. Melanocytes were found to be one of the causative agents in degrading tail tissues and were associated with the degradation of muscle, epidermis and spinal cord of the resorbing tail. PMID:22505219

  12. Cadmium-induced toxicity on larvae of the common Asian toad Duttaphrynus melanostictus (Schneider 1799): evidence from empirical trials.

    Science.gov (United States)

    Ranatunge, R A A R; Wijesinghe, M R; Ratnasooriya, W D; Dharmarathne, H A S G; Wijesekera, R D

    2012-07-01

    This paper investigates the toxicity of cadmium (Cd) on young stages of the common Asian toad Duttaphrynus melanostictus (Schneider 1799). Signs of acute toxicity were evident in tadpoles repeatedly exposed to five concentrations ranging from 0.002 to 2 mg L(-1)of Cd which included environmentally relevant levels. Mortality at concentrations of 0.02 mg L(-1) and above was enhanced from 2 % at 0.02 mg L(-1) to 100 % at 1 mg L(-1), in a dose-dependent manner. Significant growth impairment was evident at 0.20 mg L(-1) with the larvae being markedly smaller. Delayed metamorphosis and retarded swimming were also observed. Therefore levels of Cd recorded in some freshwater bodies in Sri Lanka (e.g. 0.2 mg L(-1)) may be detrimental to the young stages of D. melanostictus. PMID:22526988

  13. Checklist and Simple Identification Key for Frogs and Toads from District IV of The MADA Scheme, Kedah, Malaysia.

    Science.gov (United States)

    Jaafar, Ibrahim; Chai, Teoh Chia; Sah, Shahrul Anuar Mohd; Akil, Mohd Abdul Muin Md

    2009-12-01

    A survey was conducted to catalogue the diversity of anurans in District IV of the Muda Agriculture Development Authority Scheme (MADA) in Kedah Darul Aman, Malaysia, from July 1996 to January 1997. Eight species of anurans from three families were present in the study area. Of these, the Common Grass Frog (Fejevarya limnocharis) was the most abundant, followed by Mangrove Frog (Fejevarya cancrivora), Long-legged Frog (Hylarana macrodactyla), and Common Toad (Duttaphrynus melanostictus). Puddle Frog (Occidozyga lima), Taiwanese Giant Frog (Hoplobatrachus rugulosus), and Banded Bullfrog (Kaluola pulchra) were rare during the sampling period, and only one Paddy Frog (Hylarana erythraea) was captured. A simple identification key for the anurans of this area is included for use by scientists and laymen alike. PMID:24575178

  14. Effects of a glyphosate-based herbicide on the development of Common toads (Bufo bufo L.; Amphibia) at different temperatures

    Science.gov (United States)

    Baier, Fabian; Gruber, Edith; Spangl, Bernhard; Zaller, Johann G.

    2016-04-01

    Herbicides based on the active ingredient glyphosate are frequently applied in agriculture, horticulture and private gardens all over the world. Recently, leaching of glyphosate or its metabolite (AMPA) into water bodies inhabited by amphibians has been reported. However, very little is known about non-target effects of these herbicides on amphibians and even less is known to what extent different temperatures might alter these effects. Using climate chambers, we investigated the effects of the glyphosate-based herbicide Roundup PowerFlex® (480 g L-1 glyphosate, formulated as 588 g L-1 potassium salt) on the larval development of Common toads (Bufo bufo L.; Amphibia: Anura) under different temperature regimes (15°C vs. 20°C). We established five herbicide concentrations: 0, 1.5, 3, 4 mg acid equivalent L-1 and a 4 mg a.e. L-1 pulse treatment (totally three applications of 1.5, 1.5 and another 1 mg a.e. L-1) at each temperature in a full-factorial design. Each treatment combination was replicated five times, the experiment ran for 24 days. Results showed a highly significant effect of temperature on body length and body width but no effect of herbicide concentration on these growth parameters. Moreover, highly significant interactions between herbicide and temperature on body length and body width were observed suggesting that herbicides had different effects on different temperatures. In conclusion, although Roundup PowerFlex® at the tested concentrations appeared to have no acute toxicity to larvae of Common toads, the observed effects on tadpole morphology will potentially affect competitive interactions in spawning ponds of amphibia. Our findings of herbicide x temperature interactions might become more prevalent when human-induced climate change will lead to more extreme temperatures.

  15. Changes of body fluid and hematology in toad and their rehabilitation following intermittent exposure to simulated high altitude

    Science.gov (United States)

    Biswas, H. M.; Boral, M. C.

    1986-06-01

    Three groups of adult male toads were exposed intermittently in a decompression chamber for a daily period of 4 and 8 hours at a time for 6 consecutive days to an “altitude” of 12,000; 18,000 and 24,000 feet (3658; 5486; 7315 m) respectively. Most of the exposed animals were sacrificed immediately after the last exposure, but only a few animals experiencing 8 hours of exposure were sacrificed after a further 16 hours of exposure at normal atmospheric pressure. Eight hours of daily exposure for 6 days causes a decrease of body fluids and an increase of hematological parameters in all the altitude exposed animals compared with to the changes noted in the animals having 4 hours of daily exposure for 6 days at the same altitude levels. The animals that were exposed to pressures equivalent to altitudes of 12,000 and 18,000 feet daily for 8 hours were found to return nearly to their normal body fluids and hematological balance after 16 hours of exposure to normal atmospheric pressure, whereas the animals exposed for a similar period at an equivalent 24,000 feet failed to get back their normal balance of body fluids and hematology after 16 hours of exposure at normal atmospheric pressure. The present experiment shows that the body weight loss and changes of body fluid and hematological parameters in the toad after exposure to simulated high altitude are due not only to dehydration, but suggest that hypoxia may also have a role.

  16. Polyphyly of Asian Tree Toads, Genus Pedostibes Günther, 1876 (Anura: Bufonidae), and the Description of a New Genus from Southeast Asia

    OpenAIRE

    Kin Onn Chan; L Lee Grismer; Anil Zachariah; Brown, Rafe M.; Robin Kurian Abraham

    2016-01-01

    The Asian Tree Toad genus Pedostibes, as currently understood, exhibits a conspicuously disjunct distribution, posing several immediate questions relating to the biogeography and taxonomy of this poorly known group. The type species, P. tuberculosus and P. kempi, are known only from India, whereas P. hosii, P. rugosus, and P. everetti are restricted to Southeast Asia. Several studies have shown that these allopatric groups are polyphyletic, with the Indian Pedostibes embedded within a primari...

  17. Role of the endogenous kallikrein-kinin system in modulating vasopressin-stimulated water flow and urea permeability in the toad urinary bladder.

    OpenAIRE

    Carvounis, C P; Carvounis, G; Arbeit, L A

    1981-01-01

    This study investigates the endogenous kallikrein-kinin system's role as a modulator of vasopressin action in the toad urinary bladder. Kalli-krein inhibition by aprotinin, which results in decreased kinin production, significantly increased both vasopressin and 8-Br-cyclic (c) AMP-stimulated water flow. Kinin potentiation by the kininase II inhibitor captopril (SQ 14225) significantly decreased vasopressin and 8-Br-cAMP-stimulated water flow. In contrast to water flow, vasopressin-stimulated...

  18. Toad radiation reveals into-India dispersal as a source of endemism in the Western Ghats-Sri Lanka biodiversity hotspot

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    Bossuyt Franky

    2009-06-01

    Full Text Available Abstract Background High taxonomic level endemism in the Western Ghats-Sri Lanka biodiversity hotspot has been typically attributed to the subcontinent's geological history of long-term isolation. Subsequent out of – and into India dispersal of species after accretion to the Eurasian mainland is therefore often seen as a biogeographic factor that 'diluted' the composition of previously isolated Indian biota. However, few molecular studies have focussed on into-India dispersal as a possible source of endemism on the subcontinent. Using c. 6000 base pairs of mitochondrial and nuclear DNA, we investigated the evolutionary history and biogeography of true toads (Bufonidae, a group that colonized the Indian Subcontinent after the Indo-Asia collision. Results Contrary to previous studies, Old World toads were recovered as a nested clade within New World Bufonidae, indicating a single colonization event. Species currently classified as Ansonia and Pedostibes were both recovered as being non-monophyletic, providing evidence for the independent origin of torrential and arboreal ecomorphs on the Indian subcontinent and in South-East Asia. Our analyses also revealed a previously unrecognized adaptive radiation of toads containing a variety of larval and adult ecomorphs. Molecular dating estimates and biogeographic analyses indicate that the early diversification of this clade happened in the Western Ghats and Sri Lanka during the Late Oligocene to Early Miocene. Conclusion Paleoclimate reconstructions have shown that the Early Neogene of India was marked by major environmental changes, with the transition from a zonal- to the current monsoon-dominated climate. After arrival in the Western Ghats-Sri Lanka hotspot, toads diversified in situ, with only one lineage able to successfully disperse out of these mountains. Consequently, higher taxonomic level endemism on the Indian Subcontinent is not only the result of Cretaceous isolation, but also of invasion

  19. Polyphyly of Asian Tree Toads, Genus Pedostibes Günther, 1876 (Anura: Bufonidae), and the Description of a New Genus from Southeast Asia.

    Science.gov (United States)

    Chan, Kin Onn; Grismer, L Lee; Zachariah, Anil; Brown, Rafe M; Abraham, Robin Kurian

    2016-01-01

    The Asian Tree Toad genus Pedostibes, as currently understood, exhibits a conspicuously disjunct distribution, posing several immediate questions relating to the biogeography and taxonomy of this poorly known group. The type species, P. tuberculosus and P. kempi, are known only from India, whereas P. hosii, P. rugosus, and P. everetti are restricted to Southeast Asia. Several studies have shown that these allopatric groups are polyphyletic, with the Indian Pedostibes embedded within a primarily South Asian clade of toads, containing the genera Adenomus, Xanthophryne, and Duttaphrynus. Southeast Asian Pedostibes on the other hand, are nested within a Southeast Asian clade, which is the sister lineage to the Southeast Asian river toad genus Phrynoidis. We demonstrate that Indian and Southeast Asian Pedostibes are not only allopatric and polyphyletic, but also exhibit significant differences in morphology and reproductive mode, indicating that the Southeast Asian species' are not congeneric with the true Pedostibes of India. As a taxonomic solution, we describe a new genus, Rentapia gen. nov. to accommodate the Southeast Asian species. PMID:26788854

  20. Polyphyly of Asian Tree Toads, Genus Pedostibes Gunther, 1876 (Anura: Bufonidae, and the Description of a New Genus from Southeast Asia.

    Directory of Open Access Journals (Sweden)

    Kin Onn Chan

    Full Text Available The Asian Tree Toad genus Pedostibes, as currently understood, exhibits a conspicuously disjunct distribution, posing several immediate questions relating to the biogeography and taxonomy of this poorly known group. The type species, P. tuberculosus and P. kempi, are known only from India, whereas P. hosii, P. rugosus, and P. everetti are restricted to Southeast Asia. Several studies have shown that these allopatric groups are polyphyletic, with the Indian Pedostibes embedded within a primarily South Asian clade of toads, containing the genera Adenomus, Xanthophryne, and Duttaphrynus. Southeast Asian Pedostibes on the other hand, are nested within a Southeast Asian clade, which is the sister lineage to the Southeast Asian river toad genus Phrynoidis. We demonstrate that Indian and Southeast Asian Pedostibes are not only allopatric and polyphyletic, but also exhibit significant differences in morphology and reproductive mode, indicating that the Southeast Asian species' are not congeneric with the true Pedostibes of India. As a taxonomic solution, we describe a new genus, Rentapia gen. nov. to accommodate the Southeast Asian species.

  1. Intoxicación aguda en perro por toxinas de sapo (Bufo bufo - Acute intoxication in a dog by toxins of a toad (Bufo bufo

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    Fernández-Palacios, O´Connor, Rocío

    2009-04-01

    Full Text Available ResumenLas intoxicaciones por toxinas de sapo no son frecuentes en España y su incidencia es mayor en primavera y verano. En este trabajo describimos un caso de intoxicación aguda de una perra de 4 años de edad tras la aprehensión de un sapo (Bufo bufo en la zona de Huelva. Los signos de una intoxicación comenzaron a los 15 minutos de entrar en contacto con el sapo muriendo a las 3 horas sin responder al tratamiento suministrado (corticoides, atropina, fluidoterapia y acepromazina. Aunque el diagnóstico fue precoz, a pesar del tratamiento se produjo la muerte en 3 horas.SummaryIntoxications by toad toxins are not frequent in Spain, and its incidence is greater in spring and summer. In this work it is described a case of an acute intoxication of a dog of 4 years old by toad toxins (Bufo bufo in the area of Huelva. The animal began to show signs of intoxication 15 minutes after the contact with the toad, dying 3 hours later without any response to the provided treatment (corticoids, atropine, fluidotherapy and acepromazine. Although the diagnosis was precocious and the treatment was administrated, after 3 hours the animal died.

  2. Cytogenetic Analysis of the South American Fruit Fly Anastrepha fraterculus (Diptera:Tephritidae) Species Complex: Construction of Detailed Photographic Polytene Chromosome Maps of the Argentinian Af. sp.1 Member

    Science.gov (United States)

    Augustinos, Antonios A.; Drosopoulou, Elena; Lanzavecchia, Silvia B.; Cladera, Jorge L.; Caceres, Carlos; Bourtzis, Kostas; Mavragani-Tsipidou, Penelope; Zacharopoulou, Antigone

    2016-01-01

    Genetic and cytogenetic studies constitute a significant basis for understanding the biology of insect pests and the design and the construction of genetic tools for biological control strategies. Anastrepha fraterculus is an important pest of the Tephritidae family. It is distributed from southern Texas through eastern Mexico, Central America and South America causing significant crop damage and economic losses. Currently it is considered as a species complex; until now seven members have been described based on multidisciplinary approaches. Here we report the cytogenetic analysis of an Argentinian population characterized as Af. sp.1 member of the Anastrepha fraterculus species complex. The mitotic karyotype and the first detailed photographic maps of the salivary gland polytene chromosomes are presented. The mitotic metaphase complement consists of six (6) pairs of chromosomes, including one pair of heteromorphic sex chromosomes, with the male being the heterogametic sex. The analysis of the salivary gland polytene complement shows a total number of five long chromosomes that correspond to the five autosomes of the mitotic karyotype and a heterochromatic network corresponding to the sex chromosomes. Comparison of the polytene chromosome maps between this species and Anastrepha ludens shows significant similarity. The polytene maps presented here are suitable for cytogenetic studies that could shed light on the species limits within this species complex and support the development of genetic tools for sterile insect technique (SIT) applications. PMID:27362546

  3. Cytogenetic Analysis of the South American Fruit Fly Anastrepha fraterculus (Diptera:Tephritidae) Species Complex: Construction of Detailed Photographic Polytene Chromosome Maps of the Argentinian Af. sp.1 Member.

    Science.gov (United States)

    Gariou-Papalexiou, Angeliki; Giardini, María Cecilia; Augustinos, Antonios A; Drosopoulou, Elena; Lanzavecchia, Silvia B; Cladera, Jorge L; Caceres, Carlos; Bourtzis, Kostas; Mavragani-Tsipidou, Penelope; Zacharopoulou, Antigone

    2016-01-01

    Genetic and cytogenetic studies constitute a significant basis for understanding the biology of insect pests and the design and the construction of genetic tools for biological control strategies. Anastrepha fraterculus is an important pest of the Tephritidae family. It is distributed from southern Texas through eastern Mexico, Central America and South America causing significant crop damage and economic losses. Currently it is considered as a species complex; until now seven members have been described based on multidisciplinary approaches. Here we report the cytogenetic analysis of an Argentinian population characterized as Af. sp.1 member of the Anastrepha fraterculus species complex. The mitotic karyotype and the first detailed photographic maps of the salivary gland polytene chromosomes are presented. The mitotic metaphase complement consists of six (6) pairs of chromosomes, including one pair of heteromorphic sex chromosomes, with the male being the heterogametic sex. The analysis of the salivary gland polytene complement shows a total number of five long chromosomes that correspond to the five autosomes of the mitotic karyotype and a heterochromatic network corresponding to the sex chromosomes. Comparison of the polytene chromosome maps between this species and Anastrepha ludens shows significant similarity. The polytene maps presented here are suitable for cytogenetic studies that could shed light on the species limits within this species complex and support the development of genetic tools for sterile insect technique (SIT) applications. PMID:27362546

  4. Cytogenetic Analysis of the South American Fruit Fly Anastrepha fraterculus (Diptera:Tephritidae Species Complex: Construction of Detailed Photographic Polytene Chromosome Maps of the Argentinian Af. sp.1 Member.

    Directory of Open Access Journals (Sweden)

    Angeliki Gariou-Papalexiou

    Full Text Available Genetic and cytogenetic studies constitute a significant basis for understanding the biology of insect pests and the design and the construction of genetic tools for biological control strategies. Anastrepha fraterculus is an important pest of the Tephritidae family. It is distributed from southern Texas through eastern Mexico, Central America and South America causing significant crop damage and economic losses. Currently it is considered as a species complex; until now seven members have been described based on multidisciplinary approaches. Here we report the cytogenetic analysis of an Argentinian population characterized as Af. sp.1 member of the Anastrepha fraterculus species complex. The mitotic karyotype and the first detailed photographic maps of the salivary gland polytene chromosomes are presented. The mitotic metaphase complement consists of six (6 pairs of chromosomes, including one pair of heteromorphic sex chromosomes, with the male being the heterogametic sex. The analysis of the salivary gland polytene complement shows a total number of five long chromosomes that correspond to the five autosomes of the mitotic karyotype and a heterochromatic network corresponding to the sex chromosomes. Comparison of the polytene chromosome maps between this species and Anastrepha ludens shows significant similarity. The polytene maps presented here are suitable for cytogenetic studies that could shed light on the species limits within this species complex and support the development of genetic tools for sterile insect technique (SIT applications.

  5. Responses of toad tadpoles to ammonium nitrate fertilizer and predatory stress: differences between populations on a local scale.

    Science.gov (United States)

    Ortiz-Santaliestra, Manuel E; Fernández-Benéitez, María José; Lizana, Miguel; Marco, Adolfo

    2011-06-01

    Agriculture-related pollution is among the major causes of global amphibian population declines. The multiple stressors to which amphibians are exposed in the field, such as predation pressure, can make agrochemicals far more deadly than when they act in isolation. Even within a small area, diffuse agricultural pollution does not affect all aquatic environments equally, which could account for local differences in amphibian sensitivity to agrochemicals. We examined the combined effects of ammonium nitrate fertilizer (0 to 45.2 mg N-NH 4(+)/L) and predator stress on larval Western spadefoot toad (Pelobates cultripes), using adult caged male marbled newts (Triturus marmoratus) as predators. We compared the interaction between both stressors in tadpoles from two ponds separated by 3 km. No significant mortality was observed (survival > 80% in all cases). Local differences were detected when analyzing larval growth, with a significant interaction between factors for one of the two populations tested (Fornillos de Fermoselle). Although tadpoles exposed to 45.2 mg N-NH 4(+)/L were 7% smaller than controls, the presence of predators from a foreign community resulted in animals 15% larger than those raised without predators after 15 d of experiment. Interestingly, predators from the same community as the tadpoles did not affect larval growth. The length of the tadpoles from a nearby location (Mámoles) was unaffected after exposure to ammonium nitrate and predatory stress. PMID:21384420

  6. Variation in Chemical Defense Among Natural Populations of Common Toad, Bufo bufo, Tadpoles: the Role of Environmental Factors.

    Science.gov (United States)

    Bókony, Veronika; Móricz, Ágnes M; Tóth, Zsófia; Gál, Zoltán; Kurali, Anikó; Mikó, Zsanett; Pásztor, Katalin; Szederkényi, Márk; Tóth, Zoltán; Ujszegi, János; Üveges, Bálint; Krüzselyi, Dániel; Capon, Robert J; Hoi, Herbert; Hettyey, Attila

    2016-04-01

    Defensive toxins are widespread in nature, yet we know little about how various environmental factors shape the evolution of chemical defense, especially in vertebrates. In this study we investigated the natural variation in the amount and composition of bufadienolide toxins, and the relative importance of ecological factors in predicting that variation, in larvae of the common toad, Bufo bufo, an amphibian that produces toxins de novo. We found that tadpoles' toxin content varied markedly among populations, and the number of compounds per tadpole also differed between two geographical regions. The most consistent predictor of toxicity was the strength of competition, indicating that tadpoles produced more compounds and larger amounts of toxins when coexisting with more competitors. Additionally, tadpoles tended to contain larger concentrations of bufadienolides in ponds that were less prone to desiccation, suggesting that the costs of toxin production can only be afforded by tadpoles that do not need to drastically speed up their development. Interestingly, this trade-off was not alleviated by higher food abundance, as periphyton biomass had negligible effect on chemical defense. Even more surprisingly, we found no evidence that higher predation risk enhances chemical defenses, suggesting that low predictability of predation risk and high mortality cost of low toxicity might select for constitutive expression of chemical defense irrespective of the actual level of predation risk. Our findings highlight that the variation in chemical defense may be influenced by environmental heterogeneity in both the need for, and constraints on, toxicity as predicted by optimal defense theory. PMID:27059330

  7. Feeding pattern and use of reproductive habitat of the Striped toad Rhinella crucifer (Anura: Bufonidae from Southeastern Brazil

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    Rodrigo B. Ferreira

    2009-12-01

    Full Text Available Diet composition, foraging mode, and using of reproductive habitat of Rhinella crucifer was studied in an artificial pond in Espírito Santo, Brazil. The favored substrate was leaf litter, followed by Cyperaceae/Poaceae. Calling sites, preferred for 23.3 % (n = 7 of the observed toads, were within the water, with only the head not submerged. We analyzed a total of 61 specimens, mainly males (98.5% male and 1.5% female. Seven categories of prey were found in the stomach contents: Coleoptera, Hymenoptera (Formicidae, Isoptera, Lepidoptera, Orthoptera, Gastropoda (Mollusca, Opilionida (Arachnida. Our studies indicate that the diet of Rhinella crucifer consists mainly of terrestrial colonial arthropods. Formicidae was the predominant food item in frequency of occurrence, number of prey and weight. Isoptera and Coleoptera were also relevant in terms of weight. Neither large ontogenetic dietary nor seasonal shifts were observed in the population studied. Our results suggest that no intraspecific food resource partitioning occurs in adult or juveniles. Rhinella crucifer adults avoid competition inhabiting different home range habitats and seem to be ant-specialist with a wide foraging mode.

  8. Studies on some biochemical aspects in the toad after 48 hours of exposure to simulated high altitude

    Science.gov (United States)

    Biswas, H. M.; Boral, M. C.

    1983-06-01

    Blood glucose, tissue carbohydrate, total plasma and tissue protein and plasma electrolyte concentrations were estimated in male toads, exposed to simulated high altitude of 12,000, 18,000 and 24,000 feet respectively for 48 hours of continuous exposure in a decompression chamber. Blood glucose and muscle carbohydrate were decreased significantly in animals exposed to 18,000 and 24,000 feet altitude, without having any change in the liver carbohydrate. Muscle carbohydrate was also decreased in 12,000 feet altitude exposed animals. Plasma protein content was increased significantly in 18,000 and 24,000 feet altitude exposed animals, whereas no such change was noted in tissue protein content. A slight increase of plasma sodium concentration was found in animals exposed to 24,000 feet, and a decrease of potassium concentration was also noted in 18,000 and 24,000 feet exposed animals. Magnesium concentration of the plasma was increased in 18,000 and 24,000 feet exposed animals. This animal had also shown an eosinopenia, lymphopenia and neutrophilia when exposed at 24,000 feet high altitude.

  9. Development of 22 Polymorphic Microsatellite Loci for the Critically Endangered Morato’s Digger Toad, Proceratophrys moratoi

    Directory of Open Access Journals (Sweden)

    Shirlei Maria Recco Pimentel

    2012-09-01

    Full Text Available The Morato’s digger toad (Proceratophrys moratoi inhabits Brazilian moist savannas and is critically endangered due to its very limited geographic distribution, reduced number of isolated populations, and evidence of population decline and local extinctions. With the objective of providing tools for the genetic study of the species, 22 polymorphic microsatellite loci were isolated and screened using DNA extracted from samples of oral mucosa cells obtained from 113 individuals representing five remnant P. moratoi populations in the Brazilian state of São Paulo. These markers presented 2–18 alleles per locus, polymorphism information content (PIC of 0.02–0.87, observed heterozygosity of 0.02–0.96 and expected heterozygosity of 0.02–0.87. Three of the loci deviated significantly from Hardy–Weinberg equilibrium in one of the populations, possibly due to the presence of null alleles. Significant linkage disequilibrium was also detected between three pairs of loci. The molecular markers developed in this study were able to discriminate each of the individuals sampled (identity analysis. This means that they will be extremely useful for future genetic studies applied to the conservation of P. moratoi, providing a baseline for estimating the levels of genetic diversity, pedigrees, inbreeding, and population structure, which will be essential for the development of effective genetic management programs.

  10. A comparison of human chorionic gonadotropin and luteinizing hormone releasing hormone on the induction of spermiation and amplexus in the American toad (Anaxyrus americanus

    Directory of Open Access Journals (Sweden)

    Kouba Andrew J

    2012-08-01

    Full Text Available Abstract Background Captive breeding programs for endangered amphibian species often utilize exogenous hormones for species that are difficult to breed. The purpose of our study was to compare the efficacy of two different hormones at various concentrations on sperm production, quantity and quality over time in order to optimize assisted breeding. Methods Male American toads (Anaxyrus americanus were divided into three separate treatment groups, with animals in each group rotated through different concentrations of luteinizing hormone releasing hormone analog (LHRH; 0.1, 1.0, 4.0 and 32 micrograms/toad, human chorionic gonadotropin (hCG; 50, 100, 200, and 300 IU, or the control over 24 hours. We evaluated the number of males that respond by producing spermic urine, the sperm concentration, percent motility, and quality of forward progression. We also evaluated the effects of hCG and LHRH on reproductive behavior as assessed by amplexus. Data were analyzed using the Generalized Estimating Equations incorporating repeated measures over time and including the main effects of treatment and time, and the treatment by time interaction. Results The hormone hCG was significantly more effective at stimulating spermiation in male Anaxyrus americanus than LHRH and showed a dose-dependent response in the number of animals producing sperm. At the most effective hCG dose (300 IU, 100% of the male toads produced sperm, compared to only 35% for the best LHRH dose tested (4.0 micrograms. In addition to having a greater number of responders (P  Conclusion There is a clear dichotomy between the two hormones’ physiological responses on gamete production and stimulation of amplexus. Understanding how these two hormones influence physiology and reproductive behaviors in amphibians will have direct bearing on establishing similar breeding protocols for endangered species.

  11. Effects of landscape composition and wetland fragmentation on frog and toad abundance and species richness in Iowa and Wisconsin, USA [abstract

    Science.gov (United States)

    Knutson, M.G.; Sauer, J.R.; Olsen, D.A.; Mossman, M.J.; Hemesath, L.M.; Lannoo, M.J.

    1998-01-01

    We examined the relationships between anuran diversity and landscape features in the Upper Midwestern United States. Anuran relative abundance and species richness were measured using data collected by Wisconsin and Iowa state calling surveys conducted from 1990-1995. Landscape features surrounding survey points were determined using National Wetland Inventory and Wisconsin Wetland Inventory maps. We tested several hypotheses suggested by the literature. We hypothesized that the relative abundance and species richness of anurans that breed in ephemeral wetlands is positively correlated with the surrounding area of temporary wetlands and emergent wetlands. We hypothesized that the relative abundance and species richness of anurans is positively correlated with patch diversity and wetland edges, in the absence of local fragmentation effects. We hypothesized that the relative abundance and species richness of anurans is positively associated with forests but negatively associated with agriculture and urban areas. Our results show that the interspersion of different wetland types and the concomitant increase in wetland edge habitats were generally positive for frogs and toads and anuran abundance and diversity were generally higher in association with forests, especially forested wetlands. The presence of agriculture did not always depress frog and toad populations or diversity; some species were associated with agricultural landscapes. The two states differed in how anurans were associated with landscape features like lakes and permanent wetlands. We found that frog and toad relative abundance and diversity were lower when urban areas were present. Managers can use models like ours, generated from landscape analyses, along with range maps and population trend analyses to get a comprehensive picture of the health of individual species and groups of species. Our models could be applied to the landscape as a whole, and used to predict species relative abundance and

  12. Exposure of toad embryos and larvae to pesticides. Use of nuclear technique to determine their effect on the reproduction, survival and potential risk to Bufo arenarum populations

    International Nuclear Information System (INIS)

    Application of pesticides is currently the most common method used to control agricultural pests. However, undesired effects on non-target organisms and pollution of the soil, air and water are frequent consequences. Amphibians are good bioindicators of the presence of contaminants in the environment, because they are semi-aquatic animals located at the top of the food chain. In many parts of the world, amphibian populations are declining, and many reasons have been suggested for these losses. Although a link between widespread decline and pesticide residues has yet to be established, it is suspected that contamination of their breeding sites with pesticide residues has had a deleterious effect on the reproduction and development of amphibians. Recent experiments with a widely distributed toad, Bufo arenarum Hensel, in South America, particularly in Argentina, indicate that a variety of insecticides affects the fertilization process through the activation of an enzyme that degrades the source of second messengers and is involved in transducing the sperm signal to the oocyte. This harmful effect is not restricted to the fertilization process, since embryonic and larval development are also affected, producing severe morphological and behavioural abnormalities in embryos. Embryonic and larval development influence the timing of metamorphosis, the susceptibility to predation, survival in the terrestrial environment, and even the success of future reproduction, these being the most sensitive period of a toad's life. Evaluation of the pesticides in our region showed their presence in many of the potential breeding sites, confirming that they may influence the survival of toad populations. (author). 18 refs, 1 fig., 1 tab

  13. Joint estimation of habitat dynamics and species interactions: disturbance reduces co-occurrence of non-native predators with an endangered toad

    Science.gov (United States)

    Miller, David A.W.; Brehme, Cheryl S.; Hines, James E.; Nichols, James D.; Fisher, Robert N.

    2012-01-01

    1. Ecologists have long been interested in the processes that determine patterns of species occurrence and co-occurrence. Potential short-comings of many existing empirical approaches that address these questions include a reliance on patterns of occurrence at a single time point, failure to account properly for imperfect detection and treating the environment as a static variable. 2. We fit detection and non-detection data collected from repeat visits using a dynamic site occupancy model that simultaneously accounts for the temporal dynamics of a focal prey species, its predators and its habitat. Our objective was to determine how disturbance and species interactions affect the co-occurrence probabilities of an endangered toad and recently introduced non-native predators in stream breeding habitats. For this, we determined statistical support for alternative processes that could affect co-occurrence frequency in the system. 3. We collected occurrence data at stream segments in two watersheds where streams were largely ephemeral and one watershed dominated by perennial streams. Co-occurrence probabilities of toads with non-native predators were related to disturbance frequency, with low co-occurrence in the ephemeral watershed and high co-occurrence in the perennial watershed. This occurred because once predators were established at a site, they were rarely lost from the site except in cases when the site dried out. Once dry sites became suitable again, toads colonized them much more rapidly than predators, creating a period of predator-free space. 4. We attribute the dynamics to a storage effect, where toads persisting outside the stream environment during periods of drought rapidly colonized sites when they become suitable again. Our results support that even in highly connected stream networks, temporal disturbance can structure frequencies with which breeding amphibians encounter non-native predators. 5. Dynamic multi-state occupancy models are a powerful tool

  14. Post-Messinian evolutionary relationships across the Sicilian channel: Mitochondrial and nuclear markers link a new green toad from Sicily to African relatives

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    Lo Brutto Sabrina

    2008-02-01

    Full Text Available Abstract Background Little attention has been paid to the consequences of the last landbridge between Africa and Sicily on Mediterranean biogeography. Previous paleontological and scarce molecular data suggest possible faunal exchange later than the well-documented landbridge in the Messinian (5.3 My; however, a possible African origin of recent terrestrial Sicilian fauna has not been thoroughly tested with molecular methods. To gain insight into the phylogeography of the region, we examine two mitochondrial and two nuclear markers (one is a newly adapted intron marker in green toads (Bufo viridis subgroup across that sea barrier, the Strait of Sicily. Results Extensive sampling throughout the western Mediterranean and North Africa revealed a deep sister relationship between Sicilian (Bufo siculus n.sp. and African green toads (B. boulengeri on the mitochondrial and nuclear level. Divergence times estimated under a Bayesian-coalescence framework (mtDNA control region and 16S rRNA range from the Middle Pliocene (3.6 My to Pleistocene (0.16 My with an average (1.83 to 2.0 My around the Pliocene/Pleistocene boundary, suggesting possible land connections younger than the Messinian (5.3 My. We describe green toads from Sicily and some surrounding islands as a new endemic species (Bufo siculus. Bufo balearicus occurs on some western Mediterranean islands (Corsica, Sardinia, Mallorca, and Menorca and the Apennine Peninsula, and is well differentiated on the mitochondrial and nuclear level from B. siculus as well as from B. viridis (Laurenti, whose haplotype group reaches northeastern Italy, north of the Po River. Detection of Calabrian B. balearicus haplotypes in northeastern Sicily suggests recent invasion. Our data agree with paleogeographic and fossil data, which suggest long Plio-Pleistocene isolation of Sicily and episodic Pleistocene faunal exchange across the Strait of Messina. It remains unknown whether both species (B. balearicus, B. siculus

  15. Roles of external and cellular Cl- ions on the activation of an apical electrodiffusional Cl- pathway in toad skin.

    Science.gov (United States)

    Procopio, J; Lacaz-Vieira, F

    1990-07-01

    This study is concerned with the short-circuit current, Isc, responses of the Cl(-)-transporting cells of toad skin submitted to sudden changes of the external Cl- concentration, [Cl]o. Sudden changes of [Cl]o, carried out under apical membrane depolarization, allowed comparison of the roles of [Cl]o and [Cl]cell on the activation of the apical Cl- pathways. Equilibration of short-circuited skins symmetrically in K-Ringer's solutions of different Cl- concentrations permitted adjustment of [Cl]cell to different levels. For a given Cl- concentration (in the range of 11.7 to 117 mM) on both sides of a depolarized apical membrane, this structure exhibits a high Cl- permeability, P(Cl)apical. On the other hand, for the same range of [Cl]cell but with [Cl]o = 0, P(Cl)apical is reduced to negligible values. These observations indicate that when the apical membrane is depolarized P(Cl)apical is modulated by [Cl]o; in the absence of external Cl- ions, intracellular Cl- is not sufficient to activate P(Cl)apical. Computer simulation shows that the fast Cl- currents induced across the apical membrane by sudden shifts of [Cl]o from a control equilibrium value strictly follow the laws of electrodiffusion. For each experimental group, the computer-generated Isc versus [( Cl]cell - [Cl]o) curve which best fits the experimental data can only be obtained by a unique pair of P(Cl)apical and Rb (resistance of the basolateral membrane), thus allowing the calculation of these parameters. The electrodiffusional behavior of the net Cl- flux across the apical membrane supports the channel nature of the apical Cl- pathways in the Cl(-)-transporting cells. Cl- ions contribute significantly to the overall conductance of the basolateral membrane even in the presence of a high K concentration in the internal solution. PMID:1698229

  16. Regulation of cyclic GMP metabolism in toad photoreceptors. Definition of the metabolic events subserving photoexcited and attenuated states

    International Nuclear Information System (INIS)

    Photoreceptor metabolism of cGMP and its regulation were characterized in isolated toad retinas by determining the intensity and time dependence of light-induced changes in the following metabolic parameters: cGMP hydrolytic flux determined by the rate of 18O incorporation from 18O-water into retinal guanine nucleotide alpha-phosphoryls; changes in the total concentrations of the guanine nucleotide metabolic intermediates; and changes in the concentration of metabolic GDP calculated from the fraction of the alpha-GDP that undergoes labeling with 18O. With narrow band 500 nm light that preferentially stimulates red rod photoreceptors, a range of intensities covering approximately 5 log units produced increases of over 10-fold in cGMP metabolic flux. However, the characteristics of the cGMP metabolic response over the first 2.5 log units of intensity are readily distinguishable from those at higher intensities which exhibit progressive attenuation by an intensity- and time-dependent process. Over the range of low intensities the metabolic response is characterized by 1) increases in cGMP hydrolytic flux of up to 8-fold as a logarithmic function of intensity of photic stimulation that are sustained for at least 200 s; 2) small increases or no change in the concentration of total cGMP; 3) large increases of up to 10-fold in the concentration of metabolically active GDP as a linear function of intensity with no significant change in the tissue concentrations of total GDP or GTP; and 4) amplification of the photosignal by the metabolism of approximately 10,000 molecules of cGMP per photoisomerization with the major site of amplification at the level of the interaction of bleached rhodopsin with G-protein

  17. Population structure, historical biogeography and demographic history of the alpine toad Scutiger ningshanensis in the Tsinling Mountains of Central China.

    Directory of Open Access Journals (Sweden)

    Hongzhe Meng

    Full Text Available Population genetic structure, historical biogeography and historical demography of the alpine toad Scutiger ningshanensis were studied using the combined data mtDNA cytochrome b (cyt b and the mtDNA cytochrome c oxidase subunit I (COI as the molecular markers. This species has high genetic variation. There was a significant genetic differentiation among most populations. Three lineages were detected. The phylogenetic relationship analyses and the SAMOVA (spatial analysis of molecular variance results showed significant phylogeographic structure. 82.15% genetic variation occurred among populations whereas differentiation within populations only contributed 17.85% to the total. Mantel test results showed a significant correlation between the pairwise calculated genetic distance and pairwise calculated geographical distance of the populations (regression coefficient  = 0.001286, correlation coefficient  = 0.77051, p (rrand≥robs  = 0.0185<0.05, indicating the existence of isolation-by-distance pattern of genetic divergence for cyt b + COI sequence, which suggests that the distribution of genetic variation is due to geographical separation rather than natural selection. The population expansion or contraction and genetic differentiation between populations or lineages could be explained by topography and the repetitive uplifts of the Tsinling Mountains and the climatic cycles during the late Pliocene and Pleistocene. S. ningshanensis experienced a rapid population expansion about 40,000 years before present. The current decline in population size was probably caused by anthropogenic disturbance. Current populations of S. ningshanensis are from different refugia though the location of these refugia could not be determined in our study. Topography, climatic changes and repetitive population expansion/contraction together led to the high level of genetic variation in S. ningshanensis. A total of three management units (MUs was determined

  18. Screening breeding sites of the common toad (Bufo bufo) in England and Wales for evidence of endocrine disrupting activity.

    Science.gov (United States)

    Pickford, Daniel B; Jones, Alexandra; Velez-Pelez, Alejandra; Orton, Frances; Iguchi, Taisen; Mitsui, Naoko; Tooi, Osamu

    2015-07-01

    Anuran amphibians are often present in agricultural landscapes and may therefore be exposed to chemicals in surface waters used for breeding. We used passive accumulation devices (SPMD and POCIS) to sample contaminants from nine breeding sites of the Common toad (Bufo bufo) across England and Wales, measuring endocrine activity of the extracts in a recombinant yeast androgen screen (YAS) and yeast estrogen screen (YES) and an in vitro vitellogenin induction screen in primary culture of Xenopus laevis hepatocytes. We also assessed hatching, growth, survival, and development in caged larvae in situ, and sampled metamorphs for gonadal histopathology. None of the SPMD extracts exhibited estrogen receptor or androgen receptor agonist activity, while POCIS extracts from two sites in west-central England exhibited concentration-dependent androgenic activity in the YAS. Three sites exhibited significant estrogenic activity in both the YES and the Xenopus hepatocyte. Hatching rates varied widely among sites, but there was no consistent correlation between hatching rate and intensity of agricultural activity, predicted concentrations of agrochemicals, or endocrine activity measured in YES/YAS assays. While a small number of intersex individuals were observed, their incidence could not be associated with predicted pesticide exposure or endocrine activitity measured in the in vitro screens. There were no significant differences in sex ratio, as determined by gonadal histomorphology among the study sites, and no significant correlation was observed between proportion of males and predicted exposure to agrochemicals. However, a negative correlation did become apparent in later sampling periods between proportion of males and estrogenic activity of the POCIS sample, as measured in the YES. Our results suggest that larval and adult amphibians may be exposed to endocrine disrupting chemicals in breeding ponds, albeit at low concentrations, and that chemical contaminants other than

  19. A network extension of species occupancy models in a patchy environment applied to the Yosemite toad (Anaxyrus canorus)

    Science.gov (United States)

    Berlow, Eric L.; Knapp, Roland A.; Ostoja, Steven M.; Williams, Richard J.; McKenny, Heather; Matchett, John R.; Guo, Qinghau; Fellers, Gary M.; Kleeman, Patrick; Brooks, Matthew L.; Joppa, Lucas

    2013-01-01

    A central challenge of conservation biology is using limited data to predict rare species occurrence and identify conservation areas that play a disproportionate role in regional persistence. Where species occupy discrete patches in a landscape, such predictions require data about environmental quality of individual patches and the connectivity among high quality patches. We present a novel extension to species occupancy modeling that blends traditionalpredictions of individual patch environmental quality with network analysis to estimate connectivity characteristics using limited survey data. We demonstrate this approach using environmental and geospatial attributes to predict observed occupancy patterns of the Yosemite toad (Anaxyrus (= Bufo) canorus) across >2,500 meadows in Yosemite National Park (USA). A. canorus, a Federal Proposed Species, breeds in shallow water associated with meadows. Our generalized linear model (GLM) accurately predicted ~84% of true presence-absence data on a subset of data withheld for testing. The predicted environmental quality of each meadow was iteratively ‘boosted’ by the quality of neighbors within dispersal distance. We used this park-wide meadow connectivity network to estimate the relative influence of an individual Meadow’s ‘environmental quality’ versus its ‘network quality’ to predict: a) clusters of high quality breeding meadows potentially linked by dispersal, b) breeding meadows with high environmental quality that are isolated from other such meadows, c) breeding meadows with lower environmental quality where long-term persistence may critically depend on the network neighborhood, and d) breeding meadows with the biggest impact on park-wide breeding patterns. Combined with targeted data on dispersal, genetics, disease, and other potential stressors, these results can guide designation of core conservation areas for A. canorus in Yosemite National Park.

  20. Mixed population genomics support for the central marginal hypothesis across the invasive range of the cane toad (Rhinella marina) in Australia.

    Science.gov (United States)

    Trumbo, Daryl R; Epstein, Brendan; Hohenlohe, Paul A; Alford, Ross A; Schwarzkopf, Lin; Storfer, Andrew

    2016-09-01

    Understanding factors that cause species' geographic range limits is a major focus in ecology and evolution. The central marginal hypothesis (CMH) predicts that species cannot adapt to conditions beyond current geographic range edges because genetic diversity decreases from core to edge due to smaller, more isolated edge populations. We employed a population genomics framework using 24 235-33 112 SNP loci to test major predictions of the CMH in the ongoing invasion of the cane toad (Rhinella marina) in Australia. Cane toad tissue samples were collected along broad-scale, core-to-edge transects across their invasive range. Geographic and ecological core areas were identified using GIS and habitat suitability indices from ecological niche modelling. Bayesian clustering analyses revealed three genetic clusters, in the northwest invasion-front region, northeast precipitation-limited region and southeast cold temperature-limited region. Core-to-edge patterns of genetic diversity and differentiation were consistent with the CMH in the southeast, but were not supported in the northeast and showed mixed support in the northwest. Results suggest cold temperatures are a likely contributor to southeastern range limits, consistent with CMH predictions. In the northeast and northwest, ecological processes consisting of a steep physiological barrier and ongoing invasion dynamics, respectively, are more likely explanations for population genomic patterns than the CMH. PMID:27393238

  1. Ion transport mechanisms in the mesonephric collecting duct system of the toad Bufo bufo: microelectrode recordings from isolated and perfused tubules

    DEFF Research Database (Denmark)

    Møbjerg, Nadja; Larsen, Erik Hviid; Novak, Ivana

    2004-01-01

    It is not clear how and whether terrestrial amphibians handle NaCl transport in the distal nephron. Therefore, we studied ion transport in isolated perfused collecting tubules and ducts from toad, Bufo bufo, by means of microelectrodes. No qualitative difference in basolateral cell membrane...... amiloride application showed a small apical Na+ conductance. Arginine vasotocin depolarized Vbl. The small apical Na+ conductance indicates that the collecting duct system contributes little to NaCl reabsorption when compared to aquatic amphibians. In contrast, Vbl rapidly depolarized upon lowering of [Na......+] in the bath, demonstrating the presence of a Na+-coupled anion transporter. [HCO3-] steps revealed that this transporter is not a Na+-HCO3- cotransporter. Together, our results indicate that a major task of the collecting duct system in B. bufo is not conductive NaCl transport but rather K+ secretion...

  2. Tissue weights and adaptation response of the toad after 96 hours of exposure to simulated high altitude — A body fluid and hematological study

    Science.gov (United States)

    Biswas, H. M.; Boral, M. C.

    1985-12-01

    Adult male toads were exposed to simulated high altitude of 24,000 feet for 96 hrs of continuous exposure in a decompression chamber. The animals were sacrificed immediately after the exposure period. Significant increase of the weight of the ventricle and spleen is observed in altitude exposed animals. Red blood cell, hemoglobin concentration, hematocrit ratio and red cell mass are significantly increased in high altitude exposed animals in comparison to control. MCV (mean corpuscular volume) and MCH (mean corpuscular hemoglobin) are decreased in altitude exposed group. Plasma volume, blood volume, extracellular fluid volume, intracellular fluid volume and total body water are decreased significantly after altitude exposure for 96 hrs. These physiological changes are thought to be due to dehydration of this animal at simulated high altitude and it is highly affected after 96 hrs of exposure as evidenced by the significant reduction of total body water and intracellular fluid volume.

  3. Peptide IC-20, encoded by skin kininogen-1 of the European yellow-bellied toad, Bombina variegata, antagonizes bradykinin-induced arterial smooth muscle relaxation

    Directory of Open Access Journals (Sweden)

    Mu Yang

    2011-01-01

    Full Text Available Objectives: The objectives were to determine if the skin secretion of the European yellow-bellied toad (Bombina variegata, in common with other related species, contains a bradykinin inhibitor peptide and to isolate and structurally characterize this peptide. Materials and Methods: Lyophilized skin secretion obtained from this toad was subjected to reverse phase HPLC fractionation with subsequent bioassay of fractions for antagonism of the bradykinin activity using an isolated rat tail artery smooth muscle preparation. Subsequently, the primary structure of the peptide was established by a combination of microsequencing, mass spectroscopy, and molecular cloning, following which a synthetic replicate was chemically synthesised for bioassay. Results: A single peptide of molecular mass 2300.92 Da was resolved in HPLC fractions of skin secretion and its primary structure determined as IYNAIWP-KH-NK-KPGLL-. Database interrogation with this sequence indicated that this peptide was encoded by skin kininogen-1 previously cloned from B. variegata. The blank cycles were occupied by cysteinyl (C residues and the peptide was located toward the C-terminus of the skin kininogen, and flanked N-terminally by a classical -KR- propeptide convertase processing site. The peptide was named IC-20 in accordance (I = N-terminal isoleucine, C = C-terminal cysteine, 20 = number of residues. Like the natural peptide, its synthetic replicate displayed an antagonism of bradykinin-induced arterial smooth muscle relaxation. Conclusion: IC-20 represents a novel bradykinin antagonizing peptide from amphibian skin secretions and is the third such peptide found to be co-encoded with bradykinins within skin kininogens.

  4. Mixed Sex Effects on the Second-to-Fourth Digit Ratio of Túngara Frogs (Engystomops pustulosus) and Cane Toads (Rhinella marina).

    Science.gov (United States)

    Beaty, Lynne E; Emmering, Quinn C; Bernal, Ximena E

    2016-04-01

    Sexual dimorphism in the ratio of digit lengths has been correlated to behavioral, physiological, and morphological traits in a variety of taxa. While sexual dimorphism in the second-to-fourth digit length ratio (2D:4D) is a well-established indicator of prenatal androgen exposure in mammals, investigations into the patterns of 2D:4D and the drivers of such variation in other taxa are lacking. We used linear mixed effects models to gain a mechanistic understanding of the factors that drive variation in the scaling relationship between the lengths of the second and fourth digits in two species of anurans: túngara frogs (Engystomops pustulosus) and cane toads (Rhinella marina). We found evidence for sexual dimorphism of the 2D:4D scaling relationship on the front feet of túngara frogs, with female frogs having a larger ratio than males resulting from a relatively longer second digit on females. To our knowledge, this mammal-like pattern of sex differences in digit ratio has not yet been reported for anurans. However, given the reduced number of digits on the front feet of anurans, and uncertainty about which digit was lost during evolutionary history, this apparent sexual dimorphism in the front feet of túngara frogs should be treated with caution. In contrast, we found no evidence of sexual dimorphism in 2D:4D on either the front or rear feet of cane toads. This study highlights ambiguities in 2D:4D across taxa and suggests that further research is needed to evaluate the effect of androgens on 2D:4D in animals other than placental mammals. Anat Rec, 299:421-427, 2016. © 2016 Wiley Periodicals, Inc. PMID:26815928

  5. The genetics of amphibian declines: Population substructure and molecular differentiation in the Yosemite Toad, Bufo canorus (Anura, Bufonidae) based on single-strand conformation polymorphism analysis (SSCP) and mitochondrial DNA sequence data

    Science.gov (United States)

    Bradley, Shaffer H.; Fellers, G.M.; Magee, A.; Randal, Voss S.

    2000-01-01

    We present a comprehensive survey of genetic variation across the range of the narrowly distributed endemic Yosemite toad Bufo canorus, a declining amphibian restricted to the Sierra Nevada of California. Based on 322 bp of mitochondrial cytochrome b sequence data, we found limited support for the monophyly of B. canorus and its closely related congener B. exsul to the exclusion of the widespread western toad B. boreas. However, B. exsul was always phylogenetically nested within B. canorus, suggesting that the latter may not be monophyletic. SSCP (single-strand conformation polymorphism) analysis of 372 individual B. canorus from 28 localities in Yosemite and Kings Canyon National Parks revealed no shared haplotypes among these two regions and lead us to interpret these two parks as distinct management units for B. canorus. Within Yosemite, we found significant genetic substructure both at the level of major drainages and among breeding ponds. Kings Canyon samples show a different pattern, with substantial variation among breeding sites, but no substructure among drainages. Across the range of B. canorus as well as among Yosemite ponds, we found an isolation-by-distance pattern suggestive of a stepping stone model of migration. However, in Kings Canyon we found no hint of such a pattern, suggesting that movement patterns of toads may be quite different in these nearby parklands. Our data imply that management for B. canorus should focus at the individual pond level, and effective management may necessitate reintroductions if local extirpations occur. A brief review of other pond-breeding anurans suggests that highly structured populations are often the case, and thus that our results for B. canorus may be general for other species of frogs and toads.

  6. Nacionalismo territorialista en textos escolares: representaciones de la Patagonia en la dictadura militar argentina (1966-1983 Territorialist nationalism in school textbooks: representations of Patagonia in Argentinian military dictatorship (1966-1983

    Directory of Open Access Journals (Sweden)

    Jesús Jaramillo

    2012-03-01

    . Recent investigations focusing on the reality at schools have emphasized the textbooks' importance in the construction of national identities, and also of identities of socio-cultural, socio-ethnical, and regional.This article starts from a historiographical inquiry about school textbooks with the intent of reconstructing the various discursive textual and iconographic accounts in which Patagonia was represented in the primary schools of the provinces of Río Negro and Neuquén during the Argentinian dictatorship periods of 1966-1973 and 1976-1983. In essence, a group of narratives about Patagonia and its inhabitants was brought forward based on three cores of meaning: that of the indigenous, uncultivated and desert territory; that of the promise of progress and tourism; and that of national sovereignty. We shall argue that nationwide school textbooks of eminently political, but also ethnical and racial, slants became means of formation and, above all, auxiliary devices in the shaping of an ideological, political and pedagogical line proper to the military catholic nationalism.

  7. Dealing with waste the Argentinian way

    International Nuclear Information System (INIS)

    It is expected that the fuel element storage pool at one of Argentina's two operational power plants will be full by around February 1993. Dry storage will be used to accommodate spent fuel elements temporarily and a site for a permanent repository has been considered as part of the country's Radioactive Waste Management Programme. Management of low and intermediate level wastes from research and radioisotope production reactors, research centres, hospitals and industry is also described in this article. (author)

  8. Moessbauer study of some Argentinian chlorites

    International Nuclear Information System (INIS)

    Three chlorite samples obtained from mining areas in Mendoza, Argentina, have been studied by wet chemical analysis, X-ray diffraction and 57Fe Moessbauer spectroscopy. The total Fe contents and the Fe2+/Fe3+ atomic ratio are used to characterize the samples and are discussed in connection to the likely genesis of the minerals. (orig.)

  9. Moessbauer study of some Argentinian chlorites

    Energy Technology Data Exchange (ETDEWEB)

    Gregori, D.A. (Dept. de Geologia, Univ. Nacional del Sur, Bahia Blanca (Argentina)); Mercader, R.C. (Dept. de Fisica, Univ. Nacional de La Plata, La Plata (Argentina))

    1994-02-01

    Three chlorite samples obtained from mining areas in Mendoza, Argentina, have been studied by wet chemical analysis, X-ray diffraction and [sup 57]Fe Moessbauer spectroscopy. The total Fe contents and the Fe[sup 2+]/Fe[sup 3+] atomic ratio are used to characterize the samples and are discussed in connection to the likely genesis of the minerals. (orig.)

  10. Effects of temperature on embryonic and larval development and growth in the natterjack toad (Bufo calamita in a semi-arid zone

    Directory of Open Access Journals (Sweden)

    Sanuy, D.

    2008-06-01

    Full Text Available Temperature affects the duration of embryonic and larval periods in amphibians. Plasticity in time to metamorphosis is especially important in amphibian populations of Mediterranean semi-arid zones where temperatures are high and precipitation is low, increasing the rate of pond desiccation. In order to test the influence of water temperature on the larval development and growth of the natterjack toad (Bufo calamita, we collected two spawns in a semi¿arid zone at Balaguer (Lleida, NE Iberian peninsula. Approximately 50 (+/-10 eggs (stage 14-16 were raised in the lab at different temperature conditions: 10, 15, 20, 22.5 and 25ºC with 12:12 photoperiod. The results show a lengthening of development time with decreasing temperatures and a better survival performance of B. calamita to high temperatures. However, mean size at metamorphosis was not different across treatments, thus, suggesting that this population of B. calamita requires a minimum size to complete the metamorphosis. This study is the first approach to examine the effects that climatic factors have on the growth and development of B. calamita in semi-arid zones.

  11. Low temperature induces oocytes p34cdc2 synthesis and accumulation—the acquisition of competence to resume meiosis in toad oocytes

    Institute of Scientific and Technical Information of China (English)

    LUJINING; ZHENGGU; 等

    1996-01-01

    Full grown oocytes derived from Bufo Bufo gargarizans rearing at high temperature environment (24℃), never underwent GVBD after progesterone treatment.No p34cdc2 Hl kinase activity was detected in the oocytes after progesterone stimulation or OA microinjection;Western blotting analysis showed that the level of p34cdc2 and p33 in the oocytes are significantly lower than those in the oocytes derived from the hibernating toads (below 10℃).35S-Met incorporation analysis showed that when the oocytes were incubated at 6℃,synthesis of about thirty defferent polypeptides was promoted or induced,including p34cdc2 and some other p13suc1-binding proteins.All these results indicated that a low temperature environment is essential for the oocytes of Bufo Bufo gargarizans to express and stord some cell cycle drivers and its regulators,and to gain the maturation competence.These results will also provide a nwe clue for explaining the molecular mechanisms why gametogenesis of some organisms depends on a relative low temperature and how to maintain the geographical distribution of some animals.

  12. Influence of geology and human activity on the genetic structure and demography of the Oriental fire-bellied toad (Bombina orientalis).

    Science.gov (United States)

    Fong, Jonathan J; Li, Pi-Peng; Yang, Bao-Tian; Zhou, Zheng-Yan; Leaché, Adam D; Min, Mi-Sook; Waldman, Bruce

    2016-04-01

    The Oriental fire-bellied toad (Bombina orientalis) is a commonly used study organism, but knowledge of its evolutionary history is incomplete. We analyze sequence data from four genetic markers (mtDNA genes encoding cytochrome c oxidase subunit I, cytochrome b, and 12S-16S rRNA; nuDNA gene encoding recombination activating gene 2) from 188 individuals across its range in Northeast Asia to elucidate phylogeographic patterns and to identify the historic events that shaped its evolutionary history. Although morphologically similar across its range, B. orientalis exhibits phylogeographic structure, which we infer was shaped by geologic, climatic, and anthropogenic events. Phylogenetic and divergence-dating analyses recover four genetically distinct groups of B. orientalis: Lineage 1-Shandong Province and Beijing (China); Lineage 2-Bukhan Mountain (Korea); Lineage 3-Russia, Northeast China, and northern South Korea; and Lineage 4-South Korea. Lineage 2 was previously unknown. Additionally, we discover an area of secondary contact on the Korean Peninsula, and infer a single dispersal event as the origin of the insular Jeju population. Skyline plots estimate different population histories for the four lineages: Lineages 1 and 2 experienced population decreases, Lineage 3 remained stable, while Lineage 4 experienced a sharp increase during the Holocene. The timing of the population expansion of Lineage 4 coincides with the advent of rice cultivation, which may have facilitated the increase in population size by providing additional breeding habitat. PMID:26748269

  13. Chemical skin defence in the Eastern fire-bellied toad Bombina orientalis: an ultrastructural approach to the mechanism of poison gland rehabilitation after discharge

    Directory of Open Access Journals (Sweden)

    Sara Quagliata

    2008-12-01

    Full Text Available Type I serous glands in the skin of the Eastern yellow-bellied toad Bombina orientalis released their product massively after 10-3 M nor-adrenalin (NA stimulation, mimicking orthosympathetic control on poison emission in chemical skin defence. Features of cutaneous glands involved in this bulk discharge were observed under light and electron microscopes. Furthermore, restoration of depleted glands was followed after 1, 2 and 3 weeks, and compared with serous biosynthesis during larval gland development. Bulk discharge was caused by contraction of myoepithelial cells (mecs encircling the secretory units. Mec compression dramatically affected the secretory unit, but parts of this syncytial cytoplasm were saved from degeneration and cooperated in gland renewal with stem cells from the gland neck. These adenoblasts underwent proliferation and secretory cytodifferentiation, until merging with the syncytium. Cytoplasm that had resumed secretory activity showed the features typical of larval gland development: the endoplasmic reticulum (rer cisterns were aligned in close parallel arrangement and Golgi stacks released minute type I granules. Secretory rehabilitation led to increasing amounts of granule content. In the meantime, rough cisterns decreased in number and assumed the less ordered pattern described in control specimens. Data collected in the present study revealed that chemical skin defence in anurans is a multi-factorial mechanism involving specific activities: mechanical from mecs, biosynthetic from secretory syncytium and proliferative from intercalated stem cells.

  14. Activated G-protein releases cGMP from high affinity binding sites on PDE from toad rod outer segments (ROS)

    International Nuclear Information System (INIS)

    cGMP binding proteins in toad ROS were identified by direct photoaffinity labeling (PAL) with 32P-cGMP and quantified by retention of complexes on nitrocellulose filters. By PAL, high affinity sites were present on the α and β subunits of the cGMP-specific phosphodiesterase (PDE) which have MW/sub app/ of 94 and 90 kDa. A doublet was deduced from its photolabeling properties to represent PDE/sub γ/ photocrosslinked with PDE/sub α/ or PDE/sub β/, respectively. cGMP prebound to these high affinity sites was released by light-activated G-protein or its α subunit complexed with GTPγS; this inhibition of cGMP binding to PDE did not result from decreased cGMP availability due to enhanced hydrolysis. A low affinity cGMP binding component identified by PAL is tightly associated with ROS membranes. Apparent ATP/light-dependent stimulation of cGMP binding was shown to result from light activated cGMP hydrolysis in conjunction with ATP-promoted conversion of GMP to GDP/GTP and increased GDP/GTP binding. These findings coincide with a model for light-related regulation of cGMP binding and metabolism predicted from intact and cellfree kinetic measurements: in the dark state the cGMP hydrolic rate is constrained by the availability of cGMP because of its binding to high affinity sites on PDE. Light activated G-protein releases cGMP from these sites and allows for its redistribution to lower affinity sites represented by PDE catalytic site(s) and possible cGMP-dependent membrane cation channels

  15. Effects of landscape composition and wetland fragmentation on frog and toad abundance and species richness in Iowa and Wisconsin, U.S.A

    Science.gov (United States)

    Knutson, Melinda G.; Sauer, John R.; Olsen, Douglas A.; Mossman, Michael J.; Hemesath, Lisa M.; Lannoo, Michael J.

    1999-01-01

    Management of amphibian populations to reverse recent declines will require defining high-quality habitat for individual species or groups of species, followed by efforts to retain or restore these habitats on the landscape. We examined landscape-level habitat relationships for frogs and toads by measuring associations between relative abundance and species richness based on survey data derived from anuran calls and features of land-cover maps for Iowa and Wisconsin. The most consistent result across all anuran guilds was a negative association with the presence of urban land. Upland and wetland forests and emergent wetlands tended to be positively associated with anurans. Landscape metrics that represent edges and patch diversity also had generally positive associations, indicating that anurans benefit from a complex of habitats that include wetlands. In Iowa the most significant associations with relative abundance were the length of the edge between wetland and forest ( positive) and the presence of urban land (negative). In Wisconsin the two most significant associations with relative abundance were forest area and agricultural area ( both positive). Anurans had positive associations with agriculture in Wisconsin but not in Iowa. Remnant forest patches in agricultural landscapes may be providing refuges for some anuran species. Differences in anuran associations with deep water and permanent wetlands between the two states suggest opportunities for management action. Large-scale maps can contribute to predictive models of amphibian habitat use, but water quality and vegetation information collected from individual wetlands will likely be needed to strengthen those predictions. Landscape habitat analyses provide a framework for future experimental and intensive research on specific factors affecting the health of anurans.

  16. Synergy between glyphosate- and cypermethrin-based pesticides during acute exposures in tadpoles of the common South American toad Rhinella arenarum.

    Science.gov (United States)

    Brodeur, Julie Céline; Poliserpi, María Belén; D'Andrea, María Florencia; Sánchez, Marisol

    2014-10-01

    The herbicide glyphosate and the insecticide cypermethrin are key pesticides of modern management in soy and corn cultures. Although these pesticides are likely to co-occur in ephemeral ponds or aquatic systems supporting amphibian wildlife, the toxicological interactions prevailing in mixtures of these two pesticides have been little studied. The current study evaluated the toxicity of equitoxic and non-equitoxic binary mixtures of glyphosate- and cypermethrin-based pesticides to tadpoles of the common South American toad, Rhinella arenarum. Two different combinations of commercial products were tested: glyphosate Glifosato Atanor®+cypermethrin Xiper® and glyphosate Glifoglex®+cypermethrin Glextrin®. When tested individually, the formulations presented the following 96 h-LC50s: Glifosato Atanor® 19.4 mg ae L(-1) and Glifoglex 72.8 mg ae L(-1), Xiper® 6.8 mg L(-1) and Glextrin® 30.2 mg L(-1). Equitoxic and non-equitoxic mixtures were significantly synergic in both combinations of commercial products tested. The magnitude of the synergy (factor by which toxicity differed from concentration addition) was constant at around twofold for all tested proportions of the glyphosate Glifoglex®+cypermethrin Glextrin® mixture; whereas the magnitude of the synergy varied between 4 and 9 times in the glyphosate Glifosato Atanor®+cypermethrin Xiper® mixture. These results call for more research to be promptly undertaken in order to understand the mechanisms behind the synergy observed and to identify and quantify the extent of its environmental impacts. PMID:25048890

  17. Multilocus phylogeography of the common midwife toad, Alytes obstetricans (Anura, Alytidae): Contrasting patterns of lineage diversification and genetic structure in the Iberian refugium.

    Science.gov (United States)

    Gonçalves, H; Maia-Carvalho, B; Sousa-Neves, T; García-París, M; Sequeira, F; Ferrand, N; Martínez-Solano, I

    2015-12-01

    Recent investigations on the evolutionary history of the common midwife toad (Alytes obstetricans) revealed high levels of geographically structured genetic diversity but also a situation where delineation of major historical lineages and resolution of their relationships are much more complex than previously thought. We studied sequence variation in one mitochondrial and four nuclear genes throughout the entire distribution range of all recognized A. obstetricans subspecies to infer the evolutionary processes that shaped current patterns of genetic diversity and population subdivision. We found six divergent, geographically structured mtDNA haplogroups diagnosing population lineages, and varying levels of admixture in nuclear markers. Given the timeframe inferred for the splits between major lineages, the climatic and environmental changes that occurred during the Pleistocene seem to have shaped the diversification history of A. obstetricans. Survival of populations in allopatric refugia through the Ice Ages supports the generality of the "refugia-within-refugia" scenario for the Iberian Peninsula. However, lineages corresponding to subspecies A. o. almogavarii, A. o. pertinax, A. o. obstetricans, and A. o. boscai responded differently to Pleistocene climatic oscillations after diverging from a common ancestor. Alytes o. obstetricans expanded northward from a northern Iberian refugium through the western Pyrenees, leaving a signal of contrasting patterns of genetic diversity, with a single mtDNA haplotype north of the Pyrenees from SW France to Germany. Both A. o. pertinax and A. o. boscai are widespread and genetically diverse in Iberia, the latter comprising two divergent lineages with a long independent history. Finally, A. o. almogavarii is mostly restricted to the north-eastern corner of Iberia north of the Ebro river, with additional populations in a small region in south-eastern France. This taxon exhibits unparalleled levels of genetic diversity and little

  18. Blood lead levels, δ-ALAD inhibition, and hemoglobin content in blood of giant toad (Rhinella marina) to assess lead exposure in three areas surrounding an industrial complex in Coatzacoalcos, Veracruz, Mexico.

    Science.gov (United States)

    Ilizaliturri-Hernández, César Arturo; González-Mille, Donaji Josefina; Mejía-Saavedra, Jesús; Espinosa-Reyes, Guillermo; Torres-Dosal, Arturo; Pérez-Maldonado, Iván

    2013-02-01

    The Coatzacoalcos Region in Veracruz, Mexico houses one of the most important industrial complexes in Mexico and Latin America. Lead is an ubiquitous environmental pollutant which represents a great risk to human health and ecosystems. Amphibian populations have been recognized as biomonitors of changes in environmental conditions. The purpose of this research is to measure exposure to lead and evaluate hematological and biochemical effects in specimens of giant toads (Rhinella marina) taken from three areas surrounding an industrial complex in the Coatzacoalcos River downstream. Lead levels in toads' blood are between 10.8 and 70.6 μg/dL and are significantly higher in industrial sites. We have found a significant decrease in the delta-aminolevulinic acid dehydratase (δ-ALAD) activity in blood from 35.3 to 78 % for the urban-industrial and industrial sites, respectively. In addition, we have identified a strong inverse relationship between the δ-ALAD activity and the blood lead levels (r = -0.84, p marina can be considered a good biomonitor of the δ-ALAD activity inhibition and hematological alterations at low lead concentrations. PMID:22580791

  19. A new species of the Rhinella margaritifera species group (Anura, Bufonidae) from the montane forest of the Selva Central, Peru

    OpenAIRE

    Jiri Moravec; Edgar Lehr; Juan Carlos Cusi; Jesus Cordova; Vaclav Gvozdik

    2014-01-01

    We describe a new species of the bufonid toad genus Rhinella from transition montane forest of the buffer zones of the Yanachaga-Chemillén National Park and the Pui Pui Protected Forest (eastern slopes of Andes, Selva Central, Peru). The new species belongs to the Rhinella margaritifera species group (confirmed by mtDNA data) and differs from all its members by the absence of tympanic membrane and tympanic annulus. It is characterized by medium size (SVL 57.5–65.5 mm, n = 5), mod...

  20. Microstructure of toad (Bufo raddei) andits antioxidant and immune function%花背蟾蜍皮肤结构及其抗氧化和免疫功能的研究

    Institute of Scientific and Technical Information of China (English)

    高凤娟; 李丕鹏; 陆宇燕

    2015-01-01

    In order to understand the skin structure and function of the toad (Bufo raddei),the conventional paraffin section technique and ELISA were adopted to observe the microstructural characteristics of its dorsal skin,ventral skin and skin glands;and determine the contents of SOD,CAT,MDA,TLR4 andβD-1 of the dorsal skin and ventral skin, respectively.The results show that the toad skin structures are similar to other amphibians.That is the ventral cuticle thicker than the dorsal,the dorsal epidermis and dermis thicker than the ventral,granular glands mainly in the dorsal skin,and mucous glands in the ventral skin.SOD and TLR4 examined in the ventral skin are higher than in the dorsal skin,CAT containing in the dorsal skin is higher than in the ventral skin,but MDA andβD-1 are similar in these two areas.In conclusion,the structures and related protein levels of the toad skin closely adapt to the living environment,and have the antioxidant capacities and natural immune functions.%为了深入了解花背蟾蜍(Bufo raddei Strauch)皮肤显微结构及其相关功能,利用石蜡切片及酶联免疫吸附反应技术,观察了花背蟾蜍背腹侧皮肤及其皮肤腺的显微结构特点,分别测定了背、腹侧皮肤中 SOD、CAT、MDA、TLR4和βD-1含量。结果:花背蟾蜍皮肤结构与其他两栖类皮肤结构基本相同,其角质层腹侧较背侧厚,表皮和真皮背侧较腹侧厚;颗粒腺主要存在于背侧,而黏液腺主要存在于腹侧。SOD和TLR4含量腹侧皮肤高于背侧皮肤;CAT含量背侧皮肤较腹侧高;MDA和βD-1含量在背腹皮肤中相近。结论:花背蟾蜍皮肤结构和相关蛋白水平能够较好的适应其生境,并具有一定的抗氧化能力和天然免疫功能。

  1. 花背蟾蜍皮肤结构及其抗氧化和免疫功能的研究%Microstructure of toad (Bufo raddei) andits antioxidant and immune function

    Institute of Scientific and Technical Information of China (English)

    高凤娟; 李丕鹏; 陆宇燕

    2015-01-01

    In order to understand the skin structure and function of the toad (Bufo raddei),the conventional paraffin section technique and ELISA were adopted to observe the microstructural characteristics of its dorsal skin,ventral skin and skin glands;and determine the contents of SOD,CAT,MDA,TLR4 andβD-1 of the dorsal skin and ventral skin, respectively.The results show that the toad skin structures are similar to other amphibians.That is the ventral cuticle thicker than the dorsal,the dorsal epidermis and dermis thicker than the ventral,granular glands mainly in the dorsal skin,and mucous glands in the ventral skin.SOD and TLR4 examined in the ventral skin are higher than in the dorsal skin,CAT containing in the dorsal skin is higher than in the ventral skin,but MDA andβD-1 are similar in these two areas.In conclusion,the structures and related protein levels of the toad skin closely adapt to the living environment,and have the antioxidant capacities and natural immune functions.%为了深入了解花背蟾蜍(Bufo raddei Strauch)皮肤显微结构及其相关功能,利用石蜡切片及酶联免疫吸附反应技术,观察了花背蟾蜍背腹侧皮肤及其皮肤腺的显微结构特点,分别测定了背、腹侧皮肤中 SOD、CAT、MDA、TLR4和βD-1含量。结果:花背蟾蜍皮肤结构与其他两栖类皮肤结构基本相同,其角质层腹侧较背侧厚,表皮和真皮背侧较腹侧厚;颗粒腺主要存在于背侧,而黏液腺主要存在于腹侧。SOD和TLR4含量腹侧皮肤高于背侧皮肤;CAT含量背侧皮肤较腹侧高;MDA和βD-1含量在背腹皮肤中相近。结论:花背蟾蜍皮肤结构和相关蛋白水平能够较好的适应其生境,并具有一定的抗氧化能力和天然免疫功能。

  2. LA DIMENSIÓN ARGUMENTATIVA DE LAS MEMORIAS DISCURSIVAS: EL CASO DE LOS DISCURSOS GOLPISTAS DE LA PRENSA ESCRITA ARGENTINA (1930-1976 THE ARGUMENTATIVE DIMENSION IN DISCURSIVE MEMOIRS: THE CASE OF THE COUP D’ETAT DISCOURSES IN THE ARGENTINIAN PRESS (1930-1976

    Directory of Open Access Journals (Sweden)

    María Alejandra Vitale

    2009-06-01

    Full Text Available El propósito de este artículo es caracterizar la dimensión argumentativa de las memorias discursivas, específicamente en el caso de los editoriales y comentarios emitidos por la prensa escrita argentina para apoyar los sucesivos golpes de Estado durante el periodo 1930-1976. Para estudiar esta dimensión argumentativa en el caso aquí analizado, se denomina memoria retórico-argumental al retorno (transformación u olvido, en una serie discursiva de estrategias persuasivas que tienen la función de generar la adhesión a dichos golpes militares. Se siguieron dos vías para tal fin, en el marco de la tendencia francesa de Análisis del Discurso y desde una perspectiva retórica de estudio de la argumentación: el análisis de los tópicos y de las técnicas argumentativas.This article seeks to characterize the argumentative dimension of the discursivememory (Courtine, 1981, 1994, specifically in the case of the editorials and comments issued by the Argentinian written press in order to support the successive Coups d´Etat, during the period of 1930-1976. To analize this argumentative dimension, we called argumentative-rhetoric memory the return (the transformation or oblivion in the discursive series of persuasive strategies which, in the case here analyzed, have the function of creating the political adhesion to such Coups d´Etat. Two ways were followed within the French tendency of discourse analysis (Charaudeau & Maingueneau, 2005; Maingueneau, 1996 and from the rhetoric perspective of study of argumentation (Perelman y Olbrechts-Tyteca, 1989; Amossy, 2000: the analysis of the topics and the argumentative techniques.

  3. Nomenclatural availability of the names applied to “varieties” of the green toad (Bufo viridis subgroup in the Italian territory, with emphasis on the variety lineata of Ninni (Anura: Bufonidae

    Directory of Open Access Journals (Sweden)

    Nicola Novarini

    2010-07-01

    Full Text Available Recent molecular investigations on Eurasian green toads led to the recognition of distinct lineages and to the establishment of new taxa within the former Bufo viridis; as a consequence, significant range-wide nomenclatural changes have been proposed, although some uncertainties remained on the available names applicable within the Italian territory. In order to contribute to clarify the matter, we evaluated, under the provisions of the International Code of Zoological Nomenclature, the nomenclatural availability of all the names that have been applied to infrasubspecific entities of the Bufo viridis subgroup within the Italian territory. We also provided a historical overview of the usage of all these names, as well as detailed information on the original material upon which the variety lineata of A.P. Ninni was established. Our analysis supports the view that only the names crucigera Eichwald, 1831 and balearica Boettger, 1880 are available, the former being however junior synonym of B. viridis Laurenti, 1768, whereas the names acutirostris and obtusirostris of Lessona, lineata of Ninni, concolor and maculata of Camerano, and nardoi of Paolucci, Fuhn and Bruno are all not available.

  4. New Karyological and Morphometric Data on Poorly Known Bufo surdus and Bufo luristanicus in Comparison with Data of Diploid Green Toads of the Bufo viridis Complex from South of Iran

    Institute of Scientific and Technical Information of China (English)

    Fatemeh FAKHARZAEH; Jamshid DARVISH; Haji Gholi KAMI; Fereshteh GHASEMZADEH; Eskandar RASTEGAR-POUYANI

    2014-01-01

    Previous studies on the Bufo viridis complex, which is distributed broadly across Iran, are incomplete and restricted to a few regions or a few samples. In this paper a new detailed study on the B. viridis complex in southern of Iran (from West to East) is presented. The analysis of 18 morphometric characters with univariate and multivariate methods reveals significant differences between three members of the B. viridis complex namely B. variabilis, B. luristanicus, and B. surdus distributed in southern part of Iran. Our result help to resolve an old taxonomic problem about B. surdus subgroup (taxa closely related to B. surdus) conifrming that B. luristanicus and B. surdus are distinct species. Moreover, for the ifrst time we report and describe karyotype details of B. luristanicus and B. surdus which conifrmed that they are diploid. Karyological studies demonstrate that all toads from three mentioned species have 2n=22 chromosomes. These chromosomes are arranged into two groups. First group has six large chromosomes and the second group is composed of five small chromosomes. These chromosomes are metacentric or submetacentric. The number of submetacentric chromosomes is different in three mentioned species of B. viridis complex. Neither sexual heteromorphism, nor secondary constriction was observed in any pairs of chromosomes.

  5. USO PREHISPÁNICO DE LAS PALMERAS SYAGRUS ROMANZOFFIANA Y BUTIA YATAY EN EL NORDESTE ARGENTINO: APORTES DESDE LA ETNOGRAFÍA Y LA BIOMETRÍA / Prehispanic use of Syagrus romanzoffiana and Butia yatay palms in the Argentinian Northeast: contributions from eth

    Directory of Open Access Journals (Sweden)

    Mariano Bonomo

    2014-12-01

    Full Text Available La distribución meridional de las palmeras de la familia Arecaceae (=Palmae en Sudamérica alcanza el sur de la cuenca del Plata. Este artículo se centra en dos especies de esta familia, Syagrus romanzoffiana y Butia yatay, cuyos micro y macrorrestos se han preservado en los sitios arqueológicos del Holoceno tardío en el Nordeste argentino. El registro arqueológico indica que fueron importantes para la alimentación y, seguramente, en la tecnología. Además, grupos etnográficos pertenecientes a distintos troncos lingüísticos (tupí, macro-jê, guaycurú muestran que estos vegetales tuvieron un rol central en el Plata. A pesar de ello, hasta el presente estudio no se había efectuado en el Nordeste un análisis sistemático y desde distintas líneas de trabajo que permitan incrementar la información taxonómica y económica que se puede obtener de los restos de ambas palmeras. A partir de la revisión de la literatura etnográfica, la determinación de la utilidad neta de los frutos y el estudio de los atributos cuali-cuantitativos de los endocarpos, se establecen los usos potenciales de este recurso y la productividad de sus frutos y se brindan herramientas para la identificación taxonómica. Todo ello permite profundizar los conocimientos sobre la utilización prehispánicas de las palmeras en la región. Palabras clave: cuenca del Plata; Arecaceae; productividad de los frutos; identificación taxonómica. Prehispanic use of Syagrus romanzoffiana and Butia yatay palms in the Argentinian Northeast: contributions from ethnography and biometrics Abstract The southern distribution of the Arecaceae palm family (=Palmae in southern South America reached the La Plata Basin. This paper focuses on two species of this family, Syagrus romanzoffiana and Butia yatay which micro and macro-remains have been preserved in Late Holocene archaeological sites in the Argentinean Northeast. The archaeological record indicates that they were important in

  6. The equine arteritis virus isolate from the 2010 Argentinian outbreak.

    Science.gov (United States)

    Metz, G E; Serena, M S; Panei, C J; Nosetto, E O; Echeverria, M G

    2014-12-01

    A semen sample from a stallion infected during the 2010 equine arteritis virus (EAV) outbreak was received for viral isolation prior to castration of the animal. The virus was identified using a polyclonal antibody immunofluorescence test. Reverse-transcription polymerase chain reaction (RT-PCR) was used to amplify a region of the GP5 gene with primers GL105F and GL673R. The PCR products were purified and sequences of both strands were determined in a MegaBACE™1000 with inner primers CR2 and EAV32. A phylogenetic dataset was built with the previously reported sequences of five strains isolated in Argentina, together with a group of selected sequences obtained from GenBank. The unrooted neighbour-joining tree was constructed using molecular evolutionary genetic analysis (MEGA) and bootstrap analyses were conducted using 1,000 replicate datasets. Evolutionary distances were computed using the maximum composite likelihood method. A NetNGlyc server analysis at the Technical University of Denmark (www.cbs.dtu.dk/services/NetNGlyc/) was used to predict N-glycosylation in GP5 sequences. The phylogenetic analysis revealed that the new strain GLD-LP-ARG), together with other strains previously isolated, belongs to the European group EU-1 but in a different branch. The new strain shows 99% nucleotide identity with strain Al1and 98.1% with the Belgian strain 08P178. Persistently infected stallions and their cryopreserved semen constitute a reservoir of EAV, which ensures its persistence in the horse population around the world. These findings reinforce the importance of careful monitoring of persistently infected stallions, as well as semen straws, by RT-PCR or test mating, in accordance with national regulations. PMID:25812217

  7. Radioinhibition process in Argentinian garlic and onion bulbs

    International Nuclear Information System (INIS)

    Technological aspects of garlic and onion bulbs subjected to the radioinhibition process and extended storage under warehouse conditions were studied. Garlic and onion of the Colorado and ''Valenciana sintetica 14'' varieties respectively, were irradiated in dormancy period with an average dose of 50.0 Gy to 60Co gamma rays and kept in storage up to ten months post-harvest. Throughout the control period (180-300 days post-harvest) obvious benefits were attained as to reducing the weight loss and increasing the percentage of marketable bulbs. In general, the irradiated bulbs were superior to the non-irradiated ones with regard to the external aspect, firmness and internal aspect, while the odor of the bulbs was not affected by the process. The radioinhibition process does not seem to affect adversely the levels of dry matter, carbohydrates and ascorbic acid as well as the acidity in onion bulbs. In two marketing trials a very favourable reception was perceived in the consumer public regarding the quality of the products. These studies have promoted the construction of a multipurpose irradiation facility in the Universidad Nacional del Sur for the development of the radiation processing technology. (author)

  8. Radioinhibition process in Argentinian garlic and onion bulbs

    Science.gov (United States)

    Curzio, O. A.; Croci, C. A.

    Technological aspects of garlic and onion bulbs subjected to the radioinhibition process and extended storage under warehouse conditions were studied. Garlic and onion of the "Colorado" and "Valenciana sintética 14" varieties respectively, were irradiated in dormancy period with an average dose of 50.0 Gy of 60Co gamma rays and kept in storage up to ten months post-harvest. Throughout the control period (180-300 days post-harvest) obvious benefits were attained as to reducing the weight loss and increasing the percentage of marketable bulbs. In general, the irradiated bulbs were superior to the non-irradiated ones with regard to the external aspect, firmness and internal aspect, while the odor of the bulbs was not affected by the process. The radioinhibition process does not seem to affect adversely the levels of dry matter, carbohydrates and ascorbic acid as well as the acidity in onion bulbs. In two marketing trials a very favourable reception was perceived in the consumer public regarding the quality of the products. These studies have promoted the construction of a multipurpose irradiation facility in the Universidad Nacional del Sur for the development of the radiation processing technology.

  9. RA-10: A New Argentinian Multipurpose Research Reactor

    International Nuclear Information System (INIS)

    A new multipurpose research reactor to replace RA-3 reactor has been decided to be built in Argentina to satisfy the increasing national and regional demands for radioisotopes. The project, supported by the National Administration, has started in 2010 and is planned to be operative in 2018. The expertise acquired in the country, in the design and licensing of nuclear reactors, encourage the National Atomic Energy Commission (CNEA) to face the challenge. INVAP S.E. is involved in the design and construction of the reactor facility and related installations, playing the role of main contractor. The RA-10 is a 30 MW thermal power reactor and is designed to achieve high performance neutrons production to fulfill the stakeholder's requirements in compliance with stringent safety regulations. The principal objectives of the facility are: to consolidate and increase the radioisotope production in order to cover future demands, to provide fuel and material testing irradiation facilities to support national technology development on this field, to offer new applications in the field of science and technology based on modern neutron techniques. The reactor is an open-pool facility with a compact core with MTR (Material Testing Reactor) low enriched uranium (LEU) fuel assemblies consisting of uranium silicide fuel plates, cladded in aluminum. Reactivity control is performed by hafnium plates. A heavy water reflector tank surrounds the core. It provides a high thermal neutron flux adequate to house irradiation facilities. A diverse and independent shutdown system is engineered through its drainage. The fundamental safety objective of the design is the radiological protection of the public, the personnel and the environment and consequently the design is based in three main principles: responsibility in safety management, defense-in-depth and safety features. Engineered Safety Features are provided which are capable of maintaining the reactor in a safe condition under all anticipated operational conditions and design basis event. (author)

  10. [Bioethics in the new Argentinian Civil and Commercial Code].

    Science.gov (United States)

    Bergel, Salvador Darío

    2015-01-01

    Argentine has a new Civil and Commercial Code that will enter into force in August. This Code contains a series of rules relating to bioethics that have served to illustrate a brief comment on its contents. PMID:26665351

  11. FLORA ARGENTINA: NOVEDADES EN PRIMULACEAE Argentinian flora: novelties in Primulaceae

    Directory of Open Access Journals (Sweden)

    Sara G. Tressens

    2010-08-01

    Full Text Available

    Anagallis filiformis Cham. & Schltdl., especie no mencionada previamente para la Argentina,
    es citada, descripta e ilustrada. Se señala por primera vez A. arvensis L., ampliamente
    extendida en la Argentina, para las provincias de Corrientes y Misiones. Se incluye una clave
    para la identificación de las cuatro especies de Anagallis presentes en el país
    Anagallis filiformis Cham. & Schltdl., species not previously mentioned for Argentina is
    recorded, described and illustrated. A. arvensis L., largely widespread in Argentina, is reported
    for the first time from Corrientes and Misiones provinces. A key for the identification of the four
    species of Anagallis present in the country is also included

  12. Arroyo Toad Range - CWHR [ds612

    Data.gov (United States)

    California Department of Resources — Vector datasets of CWHR range maps are one component of California Wildlife Habitat Relationships (CWHR), a comprehensive information system and predictive model...

  13. Toads Give You Warts--Not!

    Science.gov (United States)

    Tomasek, Terry; Matthews, Catherine E.

    2008-01-01

    The authors provide activities through which teachers can share experiences in the outdoors with young children and teach them about herpetology, the study of amphibians and reptiles. Outdoor activities include observation, classification, and mapping. The authors also include activities for the classroom, including connections between the science…

  14. How Preussag Became TUI : Kissing Too Many Toads Can Make You a Toad

    NARCIS (Netherlands)

    I. Dittmann (Ingolf); E.G. Maug (Ernst); C. Schneider (Christoph)

    2006-01-01

    textabstractIn the period 1997-2004, Preussag, a diversified German conglomerate of old economy businesses, changed itself into TUI, a company focused almost entirely on tourism and logistics. This paper analyzes how this strategy was executed and how it contributed to Preussag's underperformance of

  15. Widespread convergence in toxin resistance by predictable molecular evolution.

    Science.gov (United States)

    Ujvari, Beata; Casewell, Nicholas R; Sunagar, Kartik; Arbuckle, Kevin; Wüster, Wolfgang; Lo, Nathan; O'Meally, Denis; Beckmann, Christa; King, Glenn F; Deplazes, Evelyne; Madsen, Thomas

    2015-09-22

    The question about whether evolution is unpredictable and stochastic or intermittently constrained along predictable pathways is the subject of a fundamental debate in biology, in which understanding convergent evolution plays a central role. At the molecular level, documented examples of convergence are rare and limited to occurring within specific taxonomic groups. Here we provide evidence of constrained convergent molecular evolution across the metazoan tree of life. We show that resistance to toxic cardiac glycosides produced by plants and bufonid toads is mediated by similar molecular changes to the sodium-potassium-pump (Na(+)/K(+)-ATPase) in insects, amphibians, reptiles, and mammals. In toad-feeding reptiles, resistance is conferred by two point mutations that have evolved convergently on four occasions, whereas evidence of a molecular reversal back to the susceptible state in varanid lizards migrating to toad-free areas suggests that toxin resistance is maladaptive in the absence of selection. Importantly, resistance in all taxa is mediated by replacements of 2 of the 12 amino acids comprising the Na(+)/K(+)-ATPase H1-H2 extracellular domain that constitutes a core part of the cardiac glycoside binding site. We provide mechanistic insight into the basis of resistance by showing that these alterations perturb the interaction between the cardiac glycoside bufalin and the Na(+)/K(+)-ATPase. Thus, similar selection pressures have resulted in convergent evolution of the same molecular solution across the breadth of the animal kingdom, demonstrating how a scarcity of possible solutions to a selective challenge can lead to highly predictable evolutionary responses. PMID:26372961

  16. Carotenoid composition and vitamin A value of an Argentinian squash (Cucurbita moschata).

    Science.gov (United States)

    González, E; Montenegro, M A; Nazareno, M A; López de Mishima, B A

    2001-12-01

    The carotenoid composition of butternut squash (Cucurbita moschata) cultivated in the province of Santiago del Estero, Argentina, was determined. The main carotenoids isolated were identified as beta-carotene (beta,beta-carotene), alpha-carotene (beta,epsilon-carotene), and lutein (beta,epsilon-carotene-3,3'-diol) and the minor carotenoids, as phytofluene (7,8,11,12,7',8'-hexahydro-psi,psi-carotene), zeta-carotene (7,8,7',8'-tetrahydro-psi,psi-carotene), neurosporene (7,8-dihydro-psi,psi-carotene), violaxanthin (5,6,5',6'- diepoxy-5,6,5',6'-tetrahydro-beta,beta-carotene-3,3'-diol) and neoxanthin (5,6-epoxy-6,7-didehydro-5,6,5',6'-tetrahydro-beta,beta- carotene-3,5,3'-triol). In some samples, 5,6,5',6'-beta-carotene diepoxide, (5,6,5',6'-diepoxy-5,6,5',6'-tetrahydro-beta,beta-carotene) and flavoxanthin (5,8-epoxy-5,8-dihydro-beta,epsilon-carotene-3,3'-diol) were detected. The presence of cis-isomers of beta,beta-carotene was also detected by HPLC. The vitamin A value obtained was 432 micrograms RE/100 g fresh sample, which indicates that this vegetable is an important source of provitamin A. PMID:12012567

  17. Geographical Distribution of Wild Daucus Species in the Natural Grasslands of the Argentinian Pampas

    Science.gov (United States)

    For Argentina, three wild carrot species have been described: Daucus montanus Umb. & Bonpl. ex Schult., D. montevidensis Link ex Sprengel and D. pusillus Michx. There is a discrepancy among authors about the distinctive morphological traits of the last two species; thus, it is difficult to ascertain...

  18. Diseases and remedies in modern city: environmental perspectives of argentinian eugenism between the mundial wars

    Directory of Open Access Journals (Sweden)

    Vallejo, Gustavo

    2007-06-01

    Full Text Available During the inter - war period it consolidate in Argentina a tendency to pathologize the modern city, understood like an ill organism that produced and was consequence phisical and moral decadency
    of its habitants. The interruption of external inmigration contributed with new information for a strategy of regeneration that tried to establish from eugenesics directed to articulate the populationism with the territorial distribution, in the certainty that counteracted country the evils that generated the life modern. The work reviews the impact of this ideology in the different spheres and the way in which has integrated the cultural politic of the fascism and taked part of the corpus with which the biotipology looked to give scientific legitimacy.

    Durante el período de entreguerras se consolidó en Argentina una tendencia a patologizar la ciudad moderna, entendida como un organismo enfermo que producía y a su vez era consecuencia de la decadencia física y moral de sus habitantes. La interrupción de la inmigración externa aportó nuevos datos para una estrategia de regeneración que pugnó por establecer, desde la eugenesia, medidas dirigidas a articular el poblacionismo con la distribución territorial, en la certeza de que el campo contrarrestaría los males que generaba la vida moderna. El trabajo repasa el impacto de esta ideología en distintas esferas y el modo en que ella se recepcionó junto a la política cultural del fascismo y formó parte del corpus con el que la biotipología buscó darle legitimidad científica.

  19. Trade Liberalization, Exports, and Technology Upgrading: Evidence on the Impact of MERCOSUR on Argentinian Firms

    OpenAIRE

    Bustos, Paula

    2011-01-01

    This paper studies the impact of a regional free trade agreement, MERCOSUR, on technology upgrading by Argentinean firms. To guide empirical work, I introduce technology choice in Melitz?s (2003) model of trade with heterogeneous firms. The joint treatment of the technology adoption and exporting choices shows that the increase in revenues produced by trade integration can induce exporters to upgrade technology. An empirical test of the model reveals that firms in industries fa...

  20. Keeping on employment through workers’ self- management: The case of the Argentinian empresas recuperadas

    Directory of Open Access Journals (Sweden)

    Cvejić Slobodan

    2014-01-01

    Full Text Available The phenomenon of ERTs in Argentina (Empresas recuperadas por sus trabajadores gains popularity from the financial crisis years of 1999-2002. The resulting drastic fall in gross national product, high rates of inflation, increased levels of unemployment, poverty etc., reflected the severe weaknesses and limitations of the neoliberal institutions in Argentina. This phenomenon was also determined by specific historical patterns, such as the state interventionism, a long tradition of trade unionism and workers’ struggles as well as a long and extensive tradicion of cooperativism. According to the latest survey, there are more than 300 ERT in Argentina (311, employing over 13.000 workers. (Ruggeri et al 2014. The survey results show that 95% of the ERT are self-organized under the organizational and legal framework of workers’ cooperatives. The main objective of this paper is to provide a political economic and social overview of the rise and establishment of ERTs in Argentina over the past two decades. Moreover, the legal and institutional preconditions that significantly encourage, limit, and condition the scope of workers’ cooperatives, will be analyzed. In this analysis we will rely on the results of research on ERT that have been done in last 10 years, as well as on historical analysis of legal and institutional framework.

  1. Argentinians and Peruvians in Mexico City, 1970-2009. Setting of a Transnational Digital Citizenship?

    OpenAIRE

    Fernández Tapia, Joselito

    2014-01-01

    Objective: to systematize and explain the relationship between Information and Communication Technologies -ICT and citizenship, mainly from the Internet. Methodology: a qualitative method, based on in-depth interviews, participant observation and content analysis of websites is used. The study responds to a transnational and intercultural approach to integration and citizenship.Results: state transnationalism and growing transnational networks through ICT are evidenced. They connect direct ne...

  2. Argentinian multi-wavelength scanning Raman lidar to observe night sky atmospheric transmission

    CERN Document Server

    Pallotta, Juan; Otero, Lidia; Chouza, Fernando; Raul, Delia; Gonzalez, Francisco; Etchegoyen, Alberto; Quel, Eduardo

    2013-01-01

    This paper discusses the multi-wavelength scanning Raman lidar being built at Lidar Division, CEILAP (CITEDEF-CONICET) in the frame of the Argentinean Cherenkov Telescope Array (CTA) collaboration to measure the spectral characteristics of the atmospheric aerosol extinction profiles to provide better transmission calculations at the future CTA site. This lidar emits short laser pulses of 7-9 ns at 355, 532 and 1064 nm at 50 Hz with nominal energy of 125 mJ at 1064 nm. This wavelengths are also used to retrieve the atmospheric (air, aerosol and clouds) backscattered radiation in the UV, VIS and IR ranges. Raman capabilities were added in the UV and VIS wavelengths to retrieve the spectral characteristics of the aerosol extinction and the water vapor profile. Due to the expected low aerosol optical depth of the future site, the short observation period as well as the extension of the observation, an enhanced collection area is required. This system uses six 40 cm f/2.5 newtonian telescopes to avoid dealing with...

  3. Natural Resources and Local Development: The Argentinian Oilseed Complex and Biofuel Production

    Directory of Open Access Journals (Sweden)

    Eliana Scialabba

    2014-01-01

    Full Text Available Argentina is very rich in natural resources, particularly those linked to the oilseed production. Global demand and improved means of production, have resulted in a mature and developed production infrastructure geared toward export. This generates not just revenue, but also has other positive effects, such as the creation of jobs and sustainable development. In this context, biofuel production adds multidimensional value to the vegetable oil industry and generations many spin-off industries.

  4. Characterization of cellulolytic activities of environmental bacterial consortia from an Argentinian native forest.

    Science.gov (United States)

    Romano, Nelson; Gioffré, Andrea; Sede, Silvana M; Campos, Eleonora; Cataldi, Angel; Talia, Paola

    2013-08-01

    Cellulolytic activities of three bacterial consortia derived from a forest soil sample from Chaco region, Argentina, were characterized. The phylogenetic analysis of consortia revealed two main highly supported groups including Achromobacter and Pseudomonas genera. All three consortia presented cellulolytic activity. The carboxymethylcellulase (CMCase) and total cellulase activities were studied both quantitatively and qualitatively and optimal enzymatic conditions were characterized and compared among the three consortia. Thermal and pH stability were analyzed. Based on its cellulolytic activity, one consortium was selected for further characterization by zymography. We detected a specific protein of 55 kDa with CMCase activity. In this study, we have shown that these consortia encode for cellulolytic enzymes. These enzymes could be useful for lignocellulosic biomass degradation into simple components and for different industrial applications. PMID:23471693

  5. Performance of an Argentinian acid-activated bentonite in the bleaching of soybean oil

    Directory of Open Access Journals (Sweden)

    Foletto E.L.

    2003-01-01

    Full Text Available In this work, a bentonite clay from Mendoza, Argentina was activated with H2SO4 (4 and 8 N at 90ºC for 2 and 3.5 hours. Under these conditions several cations were removed from the octahedral sheet (Mg, Al, and Fe and the DTA-TGA curves of the solids obtained after treatment were modified. Treatment time and acid concentration increased the degree of destruction of the bentonite structure. Activated samples were tested in order to verify their capacity to bleach soybean oil and were compared to a standard commercial bleaching clay. Treated samples are more efficient in bleaching than the standard.

  6. Social protest and its representations in the Argentinian press: 1996-2002

    Directory of Open Access Journals (Sweden)

    Matías Artese

    2011-07-01

    Full Text Available This article presents the main findings of a research on the relation between physical confrontations and its interpretations in six episodes of protest between 1996 and 2002 in Argentina. In this period a profound economic and employment crisis affected most of the country's population. Consequently, it was a period in which a general increase of the cycle of social protests took place.Employing tools provided by Critical Discourse Analysis, we analyze the properties attributed to each of the six protests and repressive reaction of the State, through statements published by the press.The main objective is to review the field of dispute over the meaning of the actions and characteristics of the interpretations published at the precise moments that the institutional violence was applied, as the beginning of an explanation to the criminalization of protest.

  7. Argentinian Experience and Perspectives for Small and Medium Sized Reactors. Annex I

    International Nuclear Information System (INIS)

    The National Atomic Energy Commission (CNEA) was created on 31 May 1950. It was responsible for all nuclear activities in the country until 1994. In 1994, the regulatory body and the operational activities of nuclear power plants were separated. A utility named Nucleoelectrica Argentina (NASA) was created. The present missions of the CNEA are: - To assist the national Government in nuclear policy; - To provide research and development in nuclear areas, including nuclear power plants, research reactors and nuclear fuel cycles; - To provide spent fuel and radioactive waste management, decommissioning of nuclear and radioactive installations, and environmental remediation; - By itself or through related companies, to provide radioisotopes for medicine and industry, and provide services to nuclear power plants and conventional industries. Development of human resources is yet another important objective of CNEA activities

  8. Evaluation of the psychometric properties of the Gambling Motives Questionnaire in Argentinian young people and adults.

    Science.gov (United States)

    Pilatti, Angelina; Tuzinkievich, Francisco Benjamín

    2015-01-01

    The purpose of the present study was to evaluate, in a sample of young people and adults from the general community, the psychometric properties of two models developed for assessing gambling motives (Gambling Motives Questionnaire and Gambling Motives Questionnaire-Financial; GMQ and GMQ-F). Specifically, a confirmatory factor analysis was carried out to assess the fit of the two models to the data. Internal consistency of the scales was then analyzed. A multiple regression analysis was conducted to analyze the utility of gambling motives for predicting levels of gambling problem severity. The final sample was made up of 341 young people and adults, aged 18 to 60, who reported any gambling activity during the last six months. The maximum likelihood (ML) method with robust Satorra-Bentler correction was used to evaluate the fit of the models to the data. The results indicated that both the GMQ and the GMQ-F models show a reasonable fit to the data. All scales have adequate internal consistency values. Enhancement, coping and financial gambling motives were associated with greater severity of gambling problems. Overall, the results indicate that both models have adequate psychometric properties, though the GMQ-F appears to provide a more comprehensive alternative for assessing gambling motives in the general community. PMID:25879474

  9. Enrique Pichon-Rivière: origins of Argentinian social psychology

    Directory of Open Access Journals (Sweden)

    Gastón Becerra

    2015-06-01

    Full Text Available Enrique Pichon-Rivière (1907-1977 was one of the founders of social psychology in Argentina. Here we review his biography and institutional paths along with his theoretical and epistemological contributions. We argue that Enrique Pichon-Rivière evinced a critical attitude towards the disciplinary divisions, and the distance between academic knowledge and social praxis. Here we prioritize those aspects of his work that we consider most relevant to the social sciences, including their notions of social needs, learning matrix, conceptual, referential, and operational schema (E.C.R.O., for his Spanish acronyms and convergent epistemology

  10. Initial English Language Teacher Education: Processes and Tensions towards a Unifying Curriculum in an Argentinian Province

    Science.gov (United States)

    Banegas, Dario Luis

    2014-01-01

    In this reflective piece I discuss the process of developing a new unifying initial English language teacher education curriculum in the province of Chubut (Argentina). Trainers and trainees from different institutions were called to work on it with the aim of democratising curriculum development and enhancing involvement among agents. In the…

  11. ENCOMS: Argentinian survey in cost of illness and unmet needs in multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Celica Ysrraelit

    2014-05-01

    Full Text Available The objective of the study was to assess the cost of multiple sclerosis (MS patients in Argentina categorized by disease severity using a societal perspective. Method: Cross-sectional study including MS patients from 21 MS centers in 12 cities of Argentina. Patients were stratified by disease severity using the expanded disability status scale (EDSS (group 1 with EDSS score between 0 and 3; group 2 with EDSS >3 and 3 and <7, and USD 50,712 (95%CI 47,825-62,104 for patients with EDSS ≥7. Conclusions: This is the first Argentine study evaluating the costs of MS considering disease severity.

  12. Analysis of iron state in some Argentinian soils by dissolution methods and Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Bahia Blanca (Argentina) soils, in particular entisols, are studied by Moessbauer spectroscopy. X-ray diffraction and scanning electron microscopy are used to characterize the samples. Samples were treated with different chemical iron extraction methods, in order to determine relative Feo and Fed fractions. The Feo/Fed ratios are obtained and the relative effect of iron extraction treatment on spectra components are determined. In addition, the effect of extraction procedures, dithionite-citrate-bicarbonate and oxalate, in the residual soil fraction are analyzed. (orig.)

  13. Enrique Pichon-Rivière: origins of Argentinian social psychology

    OpenAIRE

    Gastón Becerra

    2015-01-01

    Enrique Pichon-Rivière (1907-1977) was one of the founders of social psychology in Argentina. Here we review his biography and institutional paths along with his theoretical and epistemological contributions. We argue that Enrique Pichon-Rivière evinced a critical attitude towards the disciplinary divisions, and the distance between academic knowledge and social praxis. Here we prioritize those aspects of his work that we consider most relevant to the social sciences, including their notions ...

  14. Results of the argentinian intercomparison on internal dosimetry 2014. Measurement of thyroid burden

    International Nuclear Information System (INIS)

    Internal dosimetry intercomparisons are essential for the verification of the capability to perform direct measurements of “1”3”1I thyroid burden and the expertise in the interpretation of these data for dose assessment. To that aim, in 2014 the National Intercomparison Exercise was organized and coordinated by the Internal Dosimetry Laboratory of the Autoridad Regulatoria Nuclear (ARN) of Argentina. The exercise counted with the participation of six internal dosimetry services: nuclear power plants (NA-SA CNA and NA-SA CNE), CNEA Atomic Centres: Bariloche (CAB) and Ezeiza (CAE), Roffo Institute (UBA – CNEA) and ARN. This report shows a complete analysis of the participant’s results in this exercise. (authors)

  15. Sex chromosome diversity in Armenian toad grasshoppers (Orthoptera, Acridoidea, Pamphagidae)

    Science.gov (United States)

    Bugrov, Alexander G.; Jetybayev, Ilyas E.; Karagyan, Gayane H.; Rubtsov, Nicolay B.

    2016-01-01

    Abstract Although previous cytogenetic analysis of Pamphagidae grasshoppers pointed to considerable karyotype uniformity among most of the species in the family, our study of species from Armenia has discovered other, previously unknown karyotypes, differing from the standard for Pamphagidae mainly in having unusual sets of sex chromosomes. Asiotmethis turritus (Fischer von Waldheim, 1833), Paranocaracris rubripes (Fischer von Waldheim, 1846), and Nocaracris cyanipes (Fischer von Waldheim, 1846) were found to have the karyotype 2n♂=16+neo-XY and 2n♀=16+neo-XX, the neo-X chromosome being the result of centromeric fusion of an ancient acrocentric X chromosome and a large acrocentric autosome. The karyotype of Paranothrotes opacus (Brunner von Wattenwyl, 1882) was found to be 2n♂=14+X1X2Y and 2n♀=14+X1X1X2X2., the result of an additional chromosome rearrangement involving translocation of the neo-Y and another large autosome. Furthermore, evolution of the sex chromosomes in these species has involved different variants of heterochromatinization and miniaturization of the neo-Y. The karyotype of Eremopeza festiva (Saussure, 1884), in turn, appeared to have the standard sex determination system described earlier for Pamphagidae grasshoppers, 2n♂=18+X0 and 2n♀=18+XX, but all the chromosomes of this species were found to have small second C-positive arms. Using fluorescent in situ hybridization (FISH) with 18S rDNA and telomeric (TTAGG)n DNA repeats to yield new data on the structural organization of chromosomes in the species studied, we found that for most of them, clusters of repeats homologous to 18S rDNA localize on two, three or four pairs of autosomes and on the X. In Eremopeza festiva, however, FISH with labelled 18S rDNA painted C-positive regions of all autosomes and the X chromosome; clusters of telomeric repeats localized primarily on the ends of the chromosome arms. Overall, we conclude that the different stages of neo-Y degradation revealed in the Pamphagidae species studied make the family a very promising and useful model for studying sex chromosome evolution. PMID:27186337

  16. Anticipatory motor patterns limit muscle stretch during landing in toads

    OpenAIRE

    Azizi, Emanuel; Abbott, Emily M.

    2013-01-01

    To safely land after a jump or hop, muscles must be actively stretched to dissipate mechanical energy. Muscles that dissipate energy can be damaged if stretched to long lengths. The likelihood of damage may be mitigated by the nervous system, if anticipatory activation of muscles prior to impact alters the muscle's operating length. Anticipatory motor recruitment is well established in landing studies and motor patterns have been shown to be modulated based on the perceived magnitude of the i...

  17. Sex chromosome diversity in Armenian toad grasshoppers (Orthoptera, Acridoidea, Pamphagidae).

    Science.gov (United States)

    Bugrov, Alexander G; Jetybayev, Ilyas E; Karagyan, Gayane H; Rubtsov, Nicolay B

    2016-01-01

    Although previous cytogenetic analysis of Pamphagidae grasshoppers pointed to considerable karyotype uniformity among most of the species in the family, our study of species from Armenia has discovered other, previously unknown karyotypes, differing from the standard for Pamphagidae mainly in having unusual sets of sex chromosomes. Asiotmethis turritus (Fischer von Waldheim, 1833), Paranocaracris rubripes (Fischer von Waldheim, 1846), and Nocaracris cyanipes (Fischer von Waldheim, 1846) were found to have the karyotype 2n♂=16+neo-XY and 2n♀=16+neo-XX, the neo-X chromosome being the result of centromeric fusion of an ancient acrocentric X chromosome and a large acrocentric autosome. The karyotype of Paranothrotes opacus (Brunner von Wattenwyl, 1882) was found to be 2n♂=14+X1X2Y and 2n♀=14+X1X1X2X2., the result of an additional chromosome rearrangement involving translocation of the neo-Y and another large autosome. Furthermore, evolution of the sex chromosomes in these species has involved different variants of heterochromatinization and miniaturization of the neo-Y. The karyotype of Eremopeza festiva (Saussure, 1884), in turn, appeared to have the standard sex determination system described earlier for Pamphagidae grasshoppers, 2n♂=18+X0 and 2n♀=18+XX, but all the chromosomes of this species were found to have small second C-positive arms. Using fluorescent in situ hybridization (FISH) with 18S rDNA and telomeric (TTAGG)n DNA repeats to yield new data on the structural organization of chromosomes in the species studied, we found that for most of them, clusters of repeats homologous to 18S rDNA localize on two, three or four pairs of autosomes and on the X. In Eremopeza festiva, however, FISH with labelled 18S rDNA painted C-positive regions of all autosomes and the X chromosome; clusters of telomeric repeats localized primarily on the ends of the chromosome arms. Overall, we conclude that the different stages of neo-Y degradation revealed in the Pamphagidae species studied make the family a very promising and useful model for studying sex chromosome evolution. PMID:27186337

  18. Disappearance of boreal toads in Colorado: A contaminant investigation

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Population sizes of many, but not all, amphibian species have experienced declines on all six continents on which they occur (Phillips 1990, Vial and Saylor 1993)....

  19. Evolutionary reduction of developmental plasticity in desert spadefoot toads

    OpenAIRE

    Kulkarni, S.R.; Gómez-Mestre, Iván; Moskalik, C.L.; Storz, B.L.; Buchholz, D.R.

    2011-01-01

    Organisms vary their rates of growth and development in response to environmental inputs. Such developmental plasticity may be adaptive and positively correlate with environmental heterogeneity. However, the evolution of developmental plasticity among closely related taxa is not well understood. To determine the evolutionary pattern of plasticity, we compared plasticity in time to and size at metamorphosis in response to water desiccation in tadpoles among spadefoot species that differ in bre...

  20. Sodium recirculation and isotonic transport in toad small intestine

    DEFF Research Database (Denmark)

    Nedergaard, Signe Nielsen; Larsen, Erik Hviid; Ussing, Hans H.

    1999-01-01

    Small intestine; leaky epithelia; solute-coupled water transport; Na*O+ recirculation; lateral intercellular space; flux ratio analysi......Small intestine; leaky epithelia; solute-coupled water transport; Na*O+ recirculation; lateral intercellular space; flux ratio analysi...

  1. A new species of the Rhinella margaritifera species group (Anura, Bufonidae) from the montane forest of the Selva Central, Peru.

    Science.gov (United States)

    Moravec, Jiří; Lehr, Edgar; Cusi, Juan Carlos; Córdova, Jesús H; Gvoždík, Václav

    2014-01-01

    We describe a new species of the bufonid toad genus Rhinella from transition montane forest of the buffer zones of the Yanachaga-Chemillén National Park and the Pui Pui Protected Forest (eastern slopes of Andes, Selva Central, Peru). The new species belongs to the Rhinella margaritifera species group (confirmed by mtDNA data) and differs from all its members by the absence of tympanic membrane and tympanic annulus. It is characterized by medium size (SVL 57.5-65.5 mm, n = 5), moderately developed cranial crests, absence of neural crest of vertebrae, absence of bone protrusion at angle of jaw, presence of lateral rows of enlarged tubercles, and absence of subgular vocal sac and vocal slits in males. In addition, based on the molecular phylogenetic analyses of selected Rhinella species we propose the monophylum containing R. chavin, R. festae, R. macrorhina, R. manu, R. nesiotes, R. rostrata, and R. yanachaga as a new species group under the name Rhinella festae species group. PMID:24493953

  2. A new species of the Rhinella margaritifera species group (Anura, Bufonidae from the montane forest of the Selva Central, Peru

    Directory of Open Access Journals (Sweden)

    Jiri Moravec

    2014-01-01

    Full Text Available We describe a new species of the bufonid toad genus Rhinella from transition montane forest of the buffer zones of the Yanachaga-Chemillén National Park and the Pui Pui Protected Forest (eastern slopes of Andes, Selva Central, Peru. The new species belongs to the Rhinella margaritifera species group (confirmed by mtDNA data and differs from all its members by the absence of tympanic membrane and tympanic annulus. It is characterized by medium size (SVL 57.5–65.5 mm, n = 5, moderately developed cranial crests, absence of neural crest of vertebrae, absence of bone protrusion at angle of jaw, presence of lateral rows of enlarged tubercles, and absence of subgular vocal sac and vocal slits in males. In addition, based on the molecular phylogenetic analyses of selected Rhinella species we propose the monophylum containing R. chavin, R. festae, R. macrorhina, R. manu, R. nesiotes, R. rostrata, and R. yanachaga as a new species group under the name Rhinella festae species group.

  3. Irony, Humour and Cynicism in Relation to Memory. A Contrastive Analysis between the Argentinian and the Mexican Literary Field

    NARCIS (Netherlands)

    Adriaensen, B.Y.A.

    2015-01-01

    Making fun of traumatic experiences is a delicate issue. However, Freud has worked on the cathartic function of the joke (1905), and Andréa Lauterwein, in her edited volume Rire, Mémoire, Shoah (2009) insisted on the presence and relevance of laughter in the memory of the Shoah. In the context of La

  4. Late Glacial-Holocene climatic transition record at the Argentinian Andean piedmont between 33-34° S

    Science.gov (United States)

    Mehl, A. E.; Zárate, M. A.

    2013-10-01

    The Arroyo La Estacada (~33°28' S, 69°02' W), eastern Andean piedmont of Argentina, cuts through an extensive piedmont aggradational unit composed of a dominant late Pleistocene-early Holocene (LP-EH) alluvial sequence including several paleosols. The arroyo sedimentary record exhibits a paleosol developed affecting the topmost part of likely Lateglacial aeolian deposits aggraded into a floodplain environment by the end of the late Pleistocene. The paleosol shows variable grade of development in the outcrops along the arroyo probably in relation to fluvial valley paleotopography. Organic matter humification, carbonate accumulation and redox processes were the dominant processes associated with paleosol formation. By the early Holocene, when the formation of the paleosol ended, alluvial aggradation renewed and a higher frequency of flooding events could have affected the arroyo's floodplain environment. A period of relative landscape stability in the Arroyo La Estacada basin is inferred from the paleosol developed by the LP-EH transition in response to a climatic amelioration in the Andes cordillera piedmont after the Late Glacial arid conditions. The renewal of early Holocene alluvial aggradation was probably influenced by the South American Monsoon and resulted in a change in the sedimentary dynamics of the arroyo. The analyzed Late Glacial-Holocene alluvial record of the Andean piedmont constitutes a suitable record of the LP-EH climatic transition at the extra Andean region of Argentina. It is in agreement with regional paleoclimatic evidence along the southern tip of the South American continent, where other sedimentary sequences record similar late Quaternary paleoenvironmental changes over both fluvial and interfluvial areas.

  5. Obesity, overweight and socioeconomic conditions. The Argentinian CASE Obesidad, sobrepeso y condiciones socioeconómicas. El caso argentino

    OpenAIRE

    Valentina Viego; Karina Temporelli

    2012-01-01

    Obesity has been classified by the World Health Organization as a worldwide epidemic. This issue is a growing field in economics due to pathologies associated with overweight, the significant impact on healthcare costs and consequent deterioration of welfare. This paper shows the analysis of the results from the National Survey of Risk Factors in order to identify the role of socioeconomic conditions of obesity and overweight based on panel data models. The results indicate that the income le...

  6. Cuban-Argentinian Collaborative Exchange for the Implementation of a Virtual Space that Contributes to Teacher Training in Histology.

    Directory of Open Access Journals (Sweden)

    Samar, María Elena

    2011-09-01

    Full Text Available The Computer science's Technologies and the Communications, jointly with the Internet, offers an indispensable pedagogic tool for the education in our times when facilitating the collaborative integration of experiences and tacit knowledge that, stored in distant educational institutions, can be integrated in the conformation of an organizational atmosphere of common learning. From the year 2008 exist a Cuban-Argentinean collaborative exchange that connects the places web of our universities, giving the possibility that students and professors of both countries, they can enrich their knowledge with diverse materials elaborated by the two classes. The objective of this work is to present a proposal of virtual space that like form of collaborative exchange can contribute to the beginner formation of the educational ones of both countries. The antecedent of this proposal, is the Methodological Memory of the discipline Histology that has a space in the portal of Histology of Infomed that is good as repository of information to diffuse the educational-methodological knowledge. The virtual space would have materials that were good for the formation of young educational ones taking advantage of the experience of the professors of both classes for thematics. Didactics materials would be used as the cellular models, tissue and organ, interpretation of images, etc. all with the professors' comments. An exchange space would be propitiated with the educational ones interested in the proposed topics. The use of this resource type, with great quantity of information, a road of knowledge of the work that is carried out in our Universities opens up and mainly the possibilities to transfer the experiences to the educational ones young according to the most didactic and modern forms of approaching the topics in the discipline Histology.

  7. Inadvertent Trypan Blue Staining of Posterior Capsule during Cataract Surgery Associated with “Argentinian Flag” Event

    OpenAIRE

    Prinzi, Robert A.; Alapati, Neeti M.; Gappy, Shawn S.; Dilly, Jason S.

    2016-01-01

    Trypan blue is common in visualizing the anterior capsule during cataract surgery. Inadvertent staining of the posterior capsule during phacoemulsification is a rare complication and there are few reports in the literature. The proposed mechanism of posterior capsule staining in previous reports includes a compromised zonular apparatus or iris retractors facilitating the posterior flow of trypan blue. We report the first case of trypan blue staining of the posterior capsule associated with th...

  8. The origin of the gullwing-shaped cirrus above an Argentinian thunderstorm as seen in CALIPSO images

    Science.gov (United States)

    Wang, Pao K.; Cheng, Kai-Yuan; Setvak, Martin; Wang, Chen-Kang

    2016-04-01

    Gullwing-shaped cirrus layers are observed on an image above a severe thunderstorm occurred in Argentina taken by the instrument CALIOP on board of the CALIPSO satellite. The cirrus layers extended into a level in the stratosphere even higher than the above-anvil cirrus plumes that had been studied previously. This paper utilized the cloud model simulation results of a similar storm to explain the formation of such gullwing cirrus. It is shown that these cirrus layers can form from the moisture transported upward by successive internal gravity wave breaking at levels higher than the above-anvil plumes. The vertical locus of the wave crests where wave breaking occurs is itself gullwing-shaped which is the main reason why the thin cirrus layers are also gullwing shaped. Model results indicate that wave breaking can transport materials irreversibly into higher stratospheric layers and the gullwing-shaped cirrus is an evidence of this transport process.

  9. Compatibility Relations Between the Edible Carrot Daucus Carota and D. Pusillus, a Related Wild Species from the Argentinian Pampas

    Science.gov (United States)

    To establish the feasibility of hybridization between the wild carrot species Daucus pusillus Michx. (2n = 2x = 22; 2n = 2x = 22 and 20), collected in the pampas grasslands of Argentina, and the edible carrot, Daucus carota L. (2n = 2x = 18), controlled pollinations were attempted on the plant. Due ...

  10. Obesity, overweight and socioeconomic conditions. The Argentinian CASE Obesidad, sobrepeso y condiciones socioeconómicas. El caso argentino

    Directory of Open Access Journals (Sweden)

    Valentina Viego

    2012-06-01

    Full Text Available Obesity has been classified by the World Health Organization as a worldwide epidemic. This issue is a growing field in economics due to pathologies associated with overweight, the significant impact on healthcare costs and consequent deterioration of welfare. This paper shows the analysis of the results from the National Survey of Risk Factors in order to identify the role of socioeconomic conditions of obesity and overweight based on panel data models. The results indicate that the income level and sedentary lifestyle have positively influenced obesity and overweight, whereas the education and medical coverage are not relevant when explaining the differences between provinces in overweight prevalence, but become significant in the obesity rates variationsLa obesidad ha sido clasificada por la OMS como epidemia mundial. Su estudio ocupa un lugar destacado en la Economía de la Salud debido a su impacto sobre los costos sanitarios y deterioro de la calidad de vida. El objetivo de este trabajo es analizar los resultados de la Encuesta Nacional de Factores de Riesgo estableciendo la incidencia de las condiciones socioeconómicas sobre indicadores de obesidad y sobrepeso en las provincias  argentinas. Se estimó un modelo con datos de panel donde el indicador testigo de la proporción de población con problemas de peso depende de variables socioeconómicas y de variables de conducta. Los resultados indican que el nivel de ingreso y el sedentarismo tienen una influencia positiva sobre la obesidad y el sobrepeso mientras que la educación y la cobertura médica no resultan relevantes en la explicación de las diferencias entre provincias en la proporción de población con sobrepeso, pero sí se vuelven significativas para explicar las variaciones en la tasa de obesidad

  11. The foundational myth of Argentinian homeopathy. The Journal Homeopatía, Buenos Aires (1933-1940)

    OpenAIRE

    González Korzeniewski, Manuel A.

    2010-01-01

    The present article analyzes the historical-identitary construction in the older and most important institution of Homeopathy in Argentina. Two analytical axes are constructed: on the one hand, the construction of a foundational myth that outlines a genealogical thread between the «divinities» of the medicine, and on the other hand, the mitification of Hahnemann, founding father of the discipline. Using both axes we explain how the discourses of the journal were creating a symbolic support fo...

  12. Cuban-Argentinian Collaborative Exchange for the Implementation of a Virtual Space that Contributes to Teacher Training in Histology.

    OpenAIRE

    Samar, María Elena; de la C. Rodríguez Pérez, Irene; de J. Pomares Bory, Eduardo; Ávila, Rodolfo Esteban; Iglesias Ramírez, Belén Z.; Valenti Pérez, Jaime R.

    2011-01-01

    The Computer science's Technologies and the Communications, jointly with the Internet, offers an indispensable pedagogic tool for the education in our times when facilitating the collaborative integration of experiences and tacit knowledge that, stored in distant educational institutions, can be integrated in the conformation of an organizational atmosphere of common learning. From the year 2008 exist a Cuban-Argentinean collaborative exchange that connects the places web of our universities,...

  13. Drug-induced hepatotoxicity and tuberculosis in a hospital from the Argentinian northeast: cross-sectional study

    Directory of Open Access Journals (Sweden)

    Alfredo Sebastián Golemba

    2015-05-01

    Full Text Available INTRODUCCIÓN La hepatotoxicidad es un efecto adverso grave debido al tratamiento antituberculoso. OBJETIVOS El objetivo de este trabajo fue estimar la prevalencia, las formas de presentación y evolución de pacientes con hepatotoxicidad por antifímicos. MÉTODOS Se realizó un estudio observacional y descriptivo. Se incluyeron historias clínicas de pacientes mayores de 16 años, desde el 1 de enero de 2011 hasta el 30 junio de 2014 en el Servicio de Clínica Médica del Hospital Ángela I. de Llano, de Corrientes, Argentina. RESULTADOS Durante el período estudiado se diagnosticaron 118 pacientes con tuberculosis. El 7,6% (nueve pacientes, seis hombres y tres mujeres desarrolló hepatotoxicidad, de carácter hepatocelular en seis y colestásico en tres. La media de edad fue 34,6 años ± 14,3. Todos recibieron triple asociación y etambutol diariamente. Se los internó, en promedio 16 días (rango 4 a 37. Cuatro se encontraban asintomáticos, tres presentaron anorexia, náuseas y vómitos, y dos ictericia. El intervalo entre el inicio del tratamiento y la manifestación clínica fue en promedio de 9,6 días (rango 2 a 23. El intervalo entre el inicio y la suspensión del tratamiento fue en promedio 15,2 días (rango 3 a 48. Ninguno requirió trasplante hepático ni se registró ningún óbito. CONCLUSIONES La hepatotoxicidad por antifímicos se ha asociado a factores como edad mayor de 35 años, sexo femenino, embarazo, desnutrición, alcoholismo, presencia de virus de la inmunodeficiencia humana, hepatopatía previa, tratamiento diario, diabetes, insuficiencia renal, tratamiento combinado. Debido a la escasez de registros regionales, esta casuística podría ser el inicio para la creación de registros, a nivel regional y/o nacional, de efectos adversos, el establecimiento de programas de farmacovigilancia que contribuyan a la búsqueda activa de esta complicación, y el desarrollo de guías para unificar conceptos y protocolos de tratamiento específicos.

  14. The stabbing of Amelia (or how was extinguished the married women discrimination from the argentinian telephone service

    Directory of Open Access Journals (Sweden)

    Dora Barrancos

    2008-04-01

    Full Text Available This paper highlights the tracks of Amelia C. Her life story as switchboard is relevant to understand the women' s discrimination in laboral market in the early twentieth century. This article will be focused on the marital satatus as pattern of female exclusion. The strategy used by Amelia against that pattern, although individual and even desperate, detonated a series of revisions of existing legislation that were supported by different groups in society. The corpus is based on records of the telephone company in which Amelia was employed for several years and the impact of their strategies in the local press.

  15. The foundational myth of Argentinian homeopathy. The Journal Homeopatía, Buenos Aires (1933-1940

    Directory of Open Access Journals (Sweden)

    González Korzeniewski, Manuel A.

    2010-06-01

    Full Text Available The present article analyzes the historical-identitary construction in the older and most important institution of Homeopathy in Argentina. Two analytical axes are constructed: on the one hand, the construction of a foundational myth that outlines a genealogical thread between the «divinities» of the medicine, and on the other hand, the mitification of Hahnemann, founding father of the discipline. Using both axes we explain how the discourses of the journal were creating a symbolic support for the weak conjuncture in which they tried to be consolidated legally as an institution.

    El presente artículo da cuenta de la construcción identitaria-histórica en la institución de Homeopatía que actualmente es la más importante de la Argentina (y la más antigua de las vigentes. Se construyen dos ejes analíticos: por un lado, la construcción de un mito fundacional que trace un hilo genealógico entre las «divinidades» de la medicina, y por otro, la mitificación de la figura de Hahnemann, padre fundador de la disciplina. A través de ambos ejes se explica cómo los discursos de la revista creaban un sostén simbólico para la débil coyuntura en la que se procuran consolidar legalmente como institución.

  16. Concentration dependence of halide fluxes and selectivity of the anion pathway in toad skin

    DEFF Research Database (Denmark)

    Harck, A F; Larsen, Erik Hviid

    1986-01-01

    mV (apical bath negative). The active sodium currents were eliminated by replacing external Na+ with K+. With [Cl-]o varying between 1.45 mM and 110 mM (gluconate substitution) and [I-]o = 3 mM, the total clamping current (y) and the sum of halide currents (x), estimated from flux measurements, were...

  17. The dynamics of venous return and response to hypervolemia in the toad, Bufo marinus (L.)

    OpenAIRE

    Killorn, Erin E; Toews, Daniel P

    2001-01-01

    Background Venous return from the posterior region of amphibians travels by either two renal portal veins to the kidney or a central abdominal vein that drains into the hepatic portal system. The relative proportions of blood flow in these vessels has never been measured nor has a modification of flow been determined when venous return increases by changes in blood volume during hypervolemia or during increased volume input from the posterior lymph hearts. Results Venous return from the poste...

  18. Antibacterial activity of the parotid glands secretions of sudanese indigenous african toad (Bufo spp.)

    International Nuclear Information System (INIS)

    The study revealed a well-built first line innate immunity system in Bufo Spp., the skin extracts illustrated a very active antibiotic attitude which inhibited the growth of human pathogenic bacteria species, Escherichia coli (ATCC 19615), staphylococcus aureus(ATCC29213) and streptococcus pyogenes (ATCC25922). Heat treatment of secretion supported the fact that the antibacterial components possess an enzymatic attitude. Gel filtration chromatography accompanied with sensitivity tests against S.aureus showed the existence of four groups responsible for antibacterial activity in the parotoid glands secretions.(Author)

  19. Chloride transport in toad skin (Bufo viridis). The effect of salt adaptation

    DEFF Research Database (Denmark)

    Katz, U; Larsen, Erik Hviid

    1984-01-01

    The steady-state Cl- current across the skin of Bufo viridis adapted to tap water was found to be rectified. In skins bathed with NaCl Ringer on both sides, a large outward current, carried by influx of Cl-, was observed at a clamping voltage (V) of less than -50 mV (outside of the skin negative......). for V = -50 mV the transepithelial Cl- conductance calculated from isotope flux measurements was 2.5 +/- 0.3 mS cm-2, N = 10. When the skin was clamped at + 50 mV the net flux of Cl- was reversed, but Cl- conductance was only 0.3 +/- 0.1 mScm-2. Flux ratio analysis indicated that the potential......-activated Cl- conductance carries Cl- ions by way of passive transport. With NaCl Ringer bathing the outer surface of the skin the spontaneous potential was about -30 mV. At this potential the Cl- conductance of the skin was about half of its maximum value. The time course of Cl- current activation following a...

  20. Amiloride inhibits mammalian renal kallikrein and a kallikrein-like enzyme from toad bladder and skin.

    OpenAIRE

    Margolius, H S; Chao, J.

    1980-01-01

    Renal kallikrein is localized in luminal plasma membranes of the mammalian distal nephron and gains access to urine from this site. Its activity is regulated, in part, by aldosterone. These facts led us to study the effects of amiloride, a drug known to inhibit sodium reabsorption and potassium secretion at this site, on kallikrein activity. Amiloride inhibited the esterolytic activity of purified rat or human urinary kallikrein or of rat renal cortical cells upon a synthetic substrate (ID50 ...

  1. Within- and among-population variation in chytridiomycosis-induced mortality in the toad Alytes obstetricans.

    Directory of Open Access Journals (Sweden)

    Ursina Tobler

    Full Text Available BACKGROUND: Chytridiomycosis is a fungal disease linked to local and global extinctions of amphibians. Susceptibility to chytridiomycosis varies greatly between amphibian species, but little is known about between- and within-population variability. However, this kind of variability is the basis for the evolution of tolerance and resistance evolution to disease. METHODOLOGY/PRINCIPAL FINDINGS: In a common garden experiment, we measured mortality after metamorphosis of Alytes obstetricans naturally infected with Batrachochytrium dendrobatidis. Mortality rates differed significantly among populations and ranged from 27 to 90%. Within populations, mortality strongly depended on mass at and time through metamorphosis. CONCLUSIONS/SIGNIFICANCE: Although we cannot rule out that the differences observed resulted from differences in skin microbiota, different pathogen strains or environmental effects experienced by the host or the pathogen prior to the start of the experiment, we argue that genetic differences between populations are a likely source of at least part of this variation. To our knowledge, this is the first study showing differences in survival between and within populations under constant laboratory conditions. Assuming that some of this intraspecific variation has a genetic basis, this may suggest that there is the potential for the evolution of resistance or tolerance, which might allow population persistence.

  2. Soil Organic Matter Content Effects on Dermal Pesticide Bioconcentration in American Toads (Bufo Americanus)

    Science.gov (United States)

    Agricultural landscapes serve as active amphibian breeding grounds despite their seemingly poor habitat value. Activity of adults and dispersal of metamorphs to and from agricultural ponds occurs in most species from spring through late summer or early fall, a time that coincides...

  3. 75 FR 37358 - Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for the Arroyo Toad

    Science.gov (United States)

    2010-06-29

    ... 7 percent discount rate. Overall, the real estate industry (real estate development, CEQA, and delay... present value terms using a 7 percent discount rate. Overall, the real estate industry (real estate... following categories: (1) Real estate development; (2) changes in water supply; (3) grazing activities;......

  4. Cane Toad or Computer Mouse? Real and Computer-Simulated Laboratory Exercises in Physiology Classes

    Science.gov (United States)

    West, Jan; Veenstra, Anneke

    2012-01-01

    Traditional practical classes in many countries are being rationalised to reduce costs. The challenge for university educators is to provide students with the opportunity to reinforce theoretical concepts by running something other than a traditional practical program. One alternative is to replace wet labs with comparable computer simulations.…

  5. Structural analysis of toad oviductal mucosa in relation to jelly components secretion throughout the reproductive cycle.

    Science.gov (United States)

    Crespo, Claudia Alejandra; Ramos, Inés; Medina, Marcela Fátima; Cisint, Susana Beatriz; Iruzubieta Villagra, Ana Lucrecia; Fernández, Silvia Nélida

    2014-05-01

    In amphibians, the components of the jelly coats that surround the oocytes at the time of fertilization and coordinate gamete interaction are secreted by the oviduct. We analysed the histological variations in the mucosa of the oviductal pars convoluta (PC) of Rhinella arenarum during the reproductive cycle and its relationship with secretion. During the preovulatory period, the mucosa reaches a high degree of morphological and functional development, with a large number of epithelial (ESC) and glandular secretory cells (GSC) loaded with contents that are secreted into the oviductal lumen. During the ovulatory period, the secretory cells (SC) of both layers present maximum secretory activity through apocrinia and merocrinia. While the ESC located at the tips of the folds release their content directly in contact with the oocytes, the GSC secrete material from the bottom of the epithelial folds that, by interaction with the secretion of the ESC in the lateral faces, form a product with a certain degree of organization. Secretion is a continuous process with formation of coats of increasing complexity from the intermediate proximal zone (IPZ) to the pars convoluta (pc) itself, and the passage of the oocyte is a requisite for the organization of the jelly coats around the gamete. During the early postovulatory period, although there is a marked decrease in the number and volume of the SC, the ESC still release material into the oviductal lumen. In the late postovulatory period the morphological characteristics of the PC begin to recovery although there is no evidence of secretion. PMID:23174084

  6. Homeostasis and secretion of calcium in the oviductal mucosa of toad Rhinella arenarum.

    Science.gov (United States)

    Crespo, Claudia A; Medina, Marcela F; Ramos, Inés; Fernández, Silvia N

    2014-10-01

    The presence of a calcium pump, calbindin D-28KD, and calmodulin in the secretory cells (SC) of the oviductal pars convoluta (PC) of Rhinella arenarum was established for the first time in amphibians using immunohistochemical techniques. Marked variations were observed in the localization and degree of expression of these proteins according to the duct segment and the period of the sexual cycle analyzed. During the preovulatory and ovulatory periods the calcium pump colocalized with calbindin D-28KD can be seen mainly in the apical border of the SC, which are located in the first zones of PC and synthesize and secrete the components of the inner jelly coat layers. These envelopes, which surround the oocytes, contain the molecules indispensable for fertilization, probably inducing the sperm acrosome reaction (AR). Our results suggest that calmodulin, colocalized with the calcium pump at the SC cytoplasmic level, would be involved in the active transport of the cation inside the secretory granules, maintaining adequate levels of intracellular Ca(2+) . During the postreproductive period, a calcium pump colocalized with calbindin D-28KD appears for the first time in the cycle in the basal zones of the SC. This system may be related to the replenishing of intracellular Ca(2+) stores. In contrast, in R. arenarum the Ca(2+) present in the jelly coats that surround the oocytes participates in the AR during fertilization, suggesting that this secretion system of the cation provided by the oviductal mucosa is functionally more active during the reproductive period of this species. PMID:24888474

  7. Use of oxytetracycline in batch-marking post-metamorphic boreal toads

    Science.gov (United States)

    Muths, E.; Corn, P.S.; Stanley, T.R.

    2000-01-01

    Comparison of organochlorine residues in wildlife must often be made to regulatory standards or to values of known biological significance; this is difficult when dissimilar tissues are analyzed and results are expressed on different bases. To relate levels in the different tissues used for regulatory and monitoring purposes and for biological assessments, we exposed American black ducks to mixtures of three organochlorines. Differences in residue burdens among tissues were not statistically significant when levels were expressed on a lipid weight basis. Levels of heptachlor and Aroclor 1254 in one tissue can be accurately predicted from those in another; such predictions for endrin are less reliable. Lipid weight based residue concentrations in wings may be used to predict whether levels in fat exceed residue standards set for human health or approach those associated with effects on populations of species sampled.

  8. Properties of a conductive cellular chloride pathway in the skin of the toad (Bufo bufo)

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Kristensen, P

    1978-01-01

    -compartment model indicate that the strong steady-state chloride current rectification cannot be obtained if only the intracellular chloride concentration and the membrane potentials are allowed to vary ("Goldman-rectification"). It is suggested, therefore, that the premeability of the chloride pathway varies...... steady-state conductance and the steady-state chloride current reveal that the chloride pathway has maximum conductance for V approximately -80 mV (outside of the skin being negative) and approaches a non-conducting safe for V greater than 0 mV. This strong outward going rectification is a steady......-state phenomenon: In skins hyperpolarized for a few minutes, the "instantaneous" I-V curves show that the chloride pathway in the conducting state allows a large inward chloride current (outward chloride flux) to pass in the voltage range 40 mV greater than V greater than 0 mV. Calculations based on a three...

  9. A new species of arboreal toad (Anura : Bufonidae : Chaunus) from Madidi National Park, Bolivia

    Science.gov (United States)

    Padial, J.M.; Reichle, S.; McDiarmid, R.; De la Riva, I.

    2006-01-01

    A new arboreal species of the Chaunus veraguensis group is described for the humid montane forest of Madidi National Park, in northern Bolivia. The new species differs from other species in the group by the combination small size, long and slender extremities, webbed hands, conspicuous tympanic membrane, well developed parotoid glands, absence of large glands on dorsum and extremities, nuptial excrescences of males composed of pungent spines on dorsal surface of thumb, greenish-brown coloration on dorsum with red warts in life, and green iris. It is only known from two nearby localities in the Serran Eslabon, Department La Paz. An operational key for species in the C. veraguensis group is provided.

  10. Integrating Multiple Distribution Models to Guide Conservation Efforts of an Endangered Toad

    OpenAIRE

    Treglia, Michael L.; Fisher, Robert N.; Fitzgerald, Lee A.

    2015-01-01

    Species distribution models are used for numerous purposes such as predicting changes in species' ranges and identifying biodiversity hotspots. Although implications of distribution models for conservation are often implicit, few studies use these tools explicitly to inform conservation efforts. Herein, we illustrate how multiple distribution models developed using distinct sets of environmental variables can be integrated to aid in identification sites for use in conservation. We focus on th...

  11. Antimicrobial peptides from skin secretions of Chinese red belly toad Bombina maxima.

    Science.gov (United States)

    Lai, Ren; Zheng, Yong Tang; Shen, Ji Hong; Liu, Guan Jie; Liu, Hen; Lee, Wen Hui; Tang, Shao Zhong; Zhang, Yun

    2002-03-01

    Two groups of antimicrobial peptides have been isolated from skin secretions of Bombina maxima. Peptides in the first group, named maximins 1, 2, 3, 4 and 5, are structurally related to bombinin-like peptides (BLPs). Unlike BLPs, sequence variations in maximins occurred all through the molecules. In addition to the potent antimicrobial activity, cytotoxicity against tumor cells and spermicidal action of maximins, maximin 3 possessed a significant anti-HIV activity. Maximins 1 and 3 were toxic to mice with LD(50) values of 8.2 and 4.3 mg/kg, respectively. Peptides in the second group, termed maximins H1, H2, H3 and H4, are homologous with bombinin H peptides. cDNA sequences revealed that one maximin peptide plus one maximin H peptide derived from a common larger protein. PMID:11835991

  12. There are abundant antimicrobial peptides in brains of two kinds of Bombina toads.

    Science.gov (United States)

    Liu, Rui; Liu, Huan; Ma, Yufang; Wu, Jing; Yang, Hailong; Ye, Huahu; Lai, Ren

    2011-04-01

    It is well-known that there is a large amount of antimicrobial peptides in amphibian skins but few antimicrobial peptides are found in amphibian brains. Twenty-two and four antimicrobial peptides were purified and characterized from the brain homogenate of Bombina maxima and B. microdeladigitora, respectively. One hundred fifty-eight cDNA clones encoding 79 antimicrobial peptides were isolated from brain cDNA libraries of B. maxima and B. microdeladigitora. These antimicrobial peptides belong to two peptide groups (maximin and maximin-H). Twenty of them are identical to previously reported antimicrobial peptides (maximin 1-8, 10, 11, maximin H1, 3-5, 7, 9, 10, 12, 15, 16) from B. maxima skin secretions. Fifty-nine of them are novel antimicrobial peptides. Some of these antimicrobial peptides showed strong antimicrobial activities against tested microorganism strains including Gram-positive and -negative bacteria and fungi. The current diversity in peptide coding cDNA sequences is, to our knowledge, the most extreme yet described for any animal brains. The extreme diversity may give rise to interest to prospect the actual functions of antimicrobial peptides in amphibian brains. PMID:21338048

  13. Adverse effect of agroecosystem pond water on biological endpoints of common toad (Rhinella arenarum) tadpoles.

    Science.gov (United States)

    Babini, María Selene; Bionda, Clarisa de Lourdes; Salas, Nancy Edith; Martino, Adolfo Ludovico

    2016-08-01

    Chemical prroducts used in farming and wastes from livestock can contaminate pond water in agroecosystems due to runoff. Amphibians using these ponds for breeding are probably exposed to pollutants, and serious consequences might be observed afterward at the population level. Assessment biological endpoints of anuran to water quality give a realistic estimate of the probability of occurrence of adverse effects and provide an early warning signal. In this study, the ecotoxicity of agroecosystem ponds from the south of Córdoba province, Argentina, was investigated. Ponds in four sites with different degrees of human disturbance were selected: three agroecosystems (A1, A2, A3) and a site without crops or livestock (SM). The effect of pond water quality on the biological endpoint of Rhinella arenarum tadpoles was examined using microcosms with pond water from sites. Biological endpoints assessed were as follows: mortality, growth, development, morphological abnormalities (in body shape, gut, and labial tooth row formula), behavior, and blood cell parameters (micronucleus and nuclear abnormalities). Results indicated that water from agroecosystems has adverse effect on early life stage of R. arenarum. High mortality and fewer metamorphs were recorded in the A1 and A3 treatments. Tadpoles and metamorphs from A1 and A2 treatments had lower body condition. Tadpoles from A1 and A3 showed the highest prevalence of morphological abnormalities. The lowest amount of tadpoles feeding and the highest percentage of tadpoles swimming on the surface were observed in treatments with agroecosystem pond water. The higher frequencies of micronuclei and nuclear abnormalities were recorded in tadpoles from A1, A2, and A3 treatments. We check the sensitivity of the biological endpoints of R. arenarum tadpoles like early warning indicators of water quality. We found that the poor water quality of agroecosystem ponds has impact on the health of the tadpoles, and this could affect the persistence of populations. We recommend implementation of management actions before the harmful effects of agroecosystem pond water on early life stage of anuran become evident in higher ecological levels. PMID:27395360

  14. Influence of dissolved oxygen conditions on toxicity of ammonium nitrate to larval natterjack toads.

    Science.gov (United States)

    Ortiz-Santaliestra, Manuel E; Marco, Adolfo

    2015-07-01

    Temporary ponds, where many amphibians from temperate regions breed, show an annual cycle with a maximum water volume in spring followed by a progressive desiccation throughout late spring and summer. This desiccation leads to a decrease in dissolved oxygen and an increase in nitrogen levels, which can additionally increase because of anthropogenic sources such as chemical fertilizers. We analyzed the toxicity posed by environmentally relevant levels of a common nitrogenous fertilizer, ammonium nitrate, at different conditions of oxygen availability to Bufo calamita tadpoles, which typically develop in ephemeral ponds. Ammonium nitrate (90.3 mg N-NO3NH4/l) and hypoxic conditions (initial dissolved oxygen 4.53 ± 0.40 mg/l) caused significant lethal effects after 7 and 12 days of exposure, respectively. At the end of experiment (16 days), mortality rates were 32.5 % in individuals exposed to the fertilizer and 15 % in those growing under hypoxic conditions. When both stressors were combined, they showed an additive effect on tadpole survival. Malformations, such as oedemas and spinal curvatures, and locomotory abnormalities, were detected after 12 days of experiment in >90 % of individuals exposed to 45.2 mg N-NO3NH4/l under hypoxic conditions, whereas none of these stressors by separate related to abnormality rates >35 %. Delayed development was also observed in tadpoles exposed to ammonium nitrate with hypoxia affecting developmental rate only after 12 days of exposure. The results are discussed in terms of potential mechanisms linking negative effects of both factors as well as in terms of potential alterations of the ecological plasticity that often allows amphibians to survive in unpredictable environments. PMID:25586169

  15. Transformations of Aortic Arches During Metamorphosis of the Spade-Foot Toad, Pelobates fuscus

    Czech Academy of Sciences Publication Activity Database

    Majorová, H.; Roček, Zbyněk

    2004-01-01

    Roč. 260, č. 3 (2004), s. 309. ISSN 0362-2525. [International Congress of Vertebrate Morphology /7./. 27.07.2004-01.08.2004, Boca Raton] Keywords : Anura * Circulatory System * Metamorphosis Subject RIV: EA - Cell Biology

  16. Short-term evaluation of the impact of a fortified food aid program on the micronutrient nutritional status of Argentinian pregnant women.

    Science.gov (United States)

    Malpeli, Agustina; Ferrari, María Guillermina; Varea, Ana; Falivene, Mariana; Etchegoyen, Graciela; Vojkovic, María; Carmuega, Estéban; Disalvo, Liliana; Apezteguía, María; Pereyras, Silvia; Tournier, Andrea; Vogliolo, Daniel; Gonzalez, Horacio F

    2013-11-01

    We studied the impact of a food supplementation program (Plan Más Vida (PMV)) on the micronutrient nutritional condition of pregnant women from low-income families 1 year after its implementation. The food program provided supplementary diet (wheat and maize--fortified flour, rice or sugar, and fortified soup). We performed a prospective, nonexperimental, cross-sectional study in the province of Buenos Aires, Argentina, evaluating pregnant women at baseline (n = 164) and 1 year after PMV implementation (n = 108). Biochemical tests (hemogram, ferritin, vitamin A, zinc, and folic acid), anthropometric assessments (weight and height), and dietary surveys (24 h recall) were performed at the two study points. One year after PMV implementation, no significant changes in anthropometric values were observed. Folic acid deficiency and the risk of vitamin A deficiency (retinol, 20-30 μg/dl) decreased significantly (35.8 to 6.1 % and 64 to 41 %, respectively; p nutritional strategies had a high impact on the prevalence of folic acid deficiency. We also observed a decrease in the risk of vitamin A deficiency, and no impact on iron and zinc nutritional status. Adherence to the specific fortified food (soup) was not good and intra-family dilution and distribution of food was high. PMID:23999776

  17. “All men were born in Jerusalem”. Mith and gospel in the stories about the origen of humans among the toba (Qom of the Argentinian Chaco

    Directory of Open Access Journals (Sweden)

    Florencia Carmen Tola

    2011-12-01

    Full Text Available Parallelisms between stories of biblical inspiration and myths that describe the origins of the human beings, their corporal transformations and the differences between diverse types of beings can be found in contemporary narrations of the Toba people (Qom of the Argentinean Gran Chaco. Events described in the Bible are usually spun with elements of the mythical past of Toba people, therefore generating a biblical reading of the indigenous past and new readings on the human origins, of the differences between beings and of the importance of the body in the constitution of human specificity. This paper examines some of these narrations where myths and Biblical stories are interlaced giving rise to new notions of body and person.

  18. Writings, politics and human rights of the children of the Argentinian desaparecidos: new identities in Los topos and Las chanchas by Félix Bruzzone

    Directory of Open Access Journals (Sweden)

    Camilla Cattarulla

    2015-11-01

    Full Text Available After tracing the main points shaping the debate on human rights, history, memory, testimony and politics which took place in Argentina starting from the end of the last military dictatorship (1976-1983, this article will deal with the writings of the children of the desaparecidos, focussing in particular on Félix Bruzzone’s novels Los topos (2008 and Las chanchas (2014. I will propose a reading of these texts which highlights the tension between a fate seemingly decided by the actual collective memory and the capacity to modify it, thus taking distance from the canonical literature of testimony and pointing towards new kinds of identities.

  19. The Kapelusz publisher proposal for the Argentinian primary school: a quantitative and qualitative analysis of 4th year manuals in the Social Sciences area, 1976-2001

    OpenAIRE

    Romina De Luca

    2015-01-01

    The article is a contribution to the field of studies on textbooks. It analyzes the changes and continuities recorded in the “comprehensive manuals” by the Kapelusz publisher for the elementary education in Argentina between 1976 and 2001. A sample of manuals for the fourth grade published by that publisher is analyzed. The contents of social sciences, specifically History, are reviewed here. The article analyzes the changes in the manuals and their evolution is compared at the in...

  20. Results of the Argentinian intercomparison on internal dosimetry – 2014. Interpretation of monitoring data for effective dose assessment due to internal exposure

    International Nuclear Information System (INIS)

    Internal dosimetry intercomparisons are essential for the verification of the models applied and the results consistency. To that aim, in 2014 the National Intercomparison Exercise was organized and coordinated by the Internal Dosimetry Laboratory of the Nuclear Regulatory Authority (ARN) of Argentina. Four simulated cases covering intakes of “1”3”1I, “1”3”7Cs and tritium were proposed. The exercise counted with the participation of four internal dosimetry services from the nuclear power plants (NA-SA CNA and NA-SA CNE) and the CNEA Atomic Centres: Bariloche (CAB) and Ezeiza (CAE). This report shows a complete analysis of the participant’s results in this exercise. (authors)

  1. Psychometric properties of the attitudes toward gay men scale in Argentinian context: The influence of sex, authoritarianism, and social dominance orientation

    Directory of Open Access Journals (Sweden)

    Edgardo Etchezahar

    2016-01-01

    Full Text Available Even though prejudice toward male homosexuality is one of the main reasons for discrimination in Argentina, there is no valid measure to assess it. The aim of this study was to analyze the psychometric properties of the Attitudes Toward Gay Men Scale (ATG and to examine the influence of sex, right wing authoritarianism, and social dominance orientation on anti-gay attitudes. Data were collected with a convenience sample of 436 undergraduate students from University of Buenos Aires. Analysis of the data showed adequate psychometric properties for the ATG Scale and the moderating effect of sex, right wing uthoritarianism and social dominance orientation on anti-gay attitudes. Implications of these findings were discussed.

  2. Turgid female toads give males the slip: a new mechanism of female mate choice in the Anura

    OpenAIRE

    Bruning, Bas; Phillips, Benjamin L.; Shine, Richard

    2010-01-01

    In many anuran species, males vocalize to attract females but will grasp any female that comes within reach and retain their hold unless displaced by a rival male. Thus, female anurans may face strong selection to repel unwanted suitors, but no mechanism is known for doing so. We suggest that a defensive trait (the ability to inflate the body to ward off attack) has been co-opted for this role: by inflating their bodies, females are more difficult for males to grasp and hence, it is easier fo...

  3. Behavioral and neural responses of toads to salt solutions correlate with basolateral membrane potential of epidermal cells of the skin

    DEFF Research Database (Denmark)

    Hillyard, Stanley D; Baula, Victor; Tuttle, Wendy;

    2007-01-01

    (t) remained low, V(b) transiently hyperpolarized to values near the equilibrium potential for K(+) and corresponded with the reduced neural response. These results support the hypothesis that chemosensory function of the skin is analogous to that of mammalian taste cells but utilizes paracellular ion...

  4. Effects of a fungicide formulation on embryo-larval development, metamorphosis, and gonadogenesis of the South American toad Rhinella arenarum.

    Science.gov (United States)

    Svartz, Gabriela; Meijide, Fernando; Pérez Coll, Cristina

    2016-07-01

    Sublethal toxicity of the formulated fungicide Maxim(®) XL on embryonic, larval and juvenile development of Rhinella arenarum was evaluated by means of standardized bioassays. Maxim(®) XL, one of the most used fungicides in Argentina, is based on a mixture of two active ingredients: Fludioxonil and Metalaxyl-M. Maxim(®) XL exposure induced severe sublethal effects on the embryos, expressed as general underdevelopment, axial flexures, microcephaly, cellular dissociation, abnormal pigmentation, underdeveloped gills, marked edema and wavy tail. As the embryo development advanced, alterations in behavior as spasmodic contractions, general weakness and inanition were observed. Maxim(®) XL did not affect neither the time required to complete metamorphosis nor sex proportions, but gonadal development and differentiation were impaired. Gross gonadal analysis revealed a significant proportion of exposed individuals with underdevelopment of one or both gonads. Histological analysis confirmed that 18% and 10% of the individuals exposed to 0.25 and 2mg/L Maxim(®) XL, respectively, exhibited undifferentiated gonads characterized by a reduced number (or absence) of germ cells. Taking into account the risk evaluation performed by means of Hazard Quotients, this fungicide could be a threat to R. arenarum populations under chronic exposure. This study represents the first evidence of toxic effects exerted by Maxim(®) XL on amphibians. Finally, our findings highlight the properties of this fungicide that might jeopardize non-target living species exposed to it in agricultural environments. PMID:27214195

  5. Tracking Amendments to Legislation and Other Political Texts with a Novel Minimum-Edit-Distance Algorithm: DocuToads

    DEFF Research Database (Denmark)

    Hermansson, Henrik Alf Jonas; Cross, James

    2015-01-01

    Political scientists often nd themselves tracking amendments to political texts. As different actors weigh in, texts change as they are drafted and redrafted, reflecting political preferences and power. This study provides a novel solution to the problem of detecting amendments to political text......) and substantive amount of amendments made between version of texts. To illustrate the usefulness and eciency of the approach we replicate two existing studies from the field of legislative studies. Our results demonstrate that minimum edit distance methods can produce superior measures of text amendments to hand...

  6. The dynamics of venous return and response to hypervolemia in the toad, Bufo marinus (L.)

    OpenAIRE

    Toews Daniel P; Killorn Erin E

    2001-01-01

    Abstract Background Venous return from the posterior region of amphibians travels by either two renal portal veins to the kidney or a central abdominal vein that drains into the hepatic portal system. The relative proportions of blood flow in these vessels has never been measured nor has a modification of flow been determined when venous return increases by changes in blood volume during hypervolemia or during increased volume input from the posterior lymph hearts. Results Venous return from ...

  7. Distribution of Boreal Toad Populations in Relation to Estimated UV-B Dose in Glacier National Park, Montana, USA

    Science.gov (United States)

    This work provides information on amphibian distributions as well as the range of UV-B exposure in mountain habitats, and will be of use to scientists interested in tracking changes in amphibian distributions and abundance, and spatial and temporal patterns of UV-B exposure

  8. The straight and narrow path: the evolution of straight-line dispersal at a cane toad invasion front

    OpenAIRE

    Brown, Gregory P.; Phillips, Benjamin L.; Shine, Richard

    2014-01-01

    At the edge of a biological invasion, evolutionary processes (spatial sorting, natural selection) often drive increases in dispersal. Although numerous traits influence an individual's displacement (e.g. speed, stamina), one of the most important is path straightness. A straight (i.e. highly correlated) path strongly enhances overall dispersal rate relative to time and energetic cost. Thus, we predict that, if path straightness has a genetic basis, organisms in the invasion vanguard will exhi...

  9. Quantitative study of Trichodina heterodentata (Ciliophora: Mobilia infrapopulations infesting tadpoles of a Brazilian endemic toad Rhinella pombali (Anura: Bufonidae

    Directory of Open Access Journals (Sweden)

    Noemi M. Fernandes

    2011-12-01

    Full Text Available In this work we investigated the quantitative aspects of the relationship between Rhinella pombali (Baldissera, Caramaschi & Haddad, 2004 tadpoles and their trichodinid ectoparasites. Specimens were collected from a small stream located at an agricultural area between rainforest fragments in southeastern Brazil. A total of 80 tadpoles were investigated. Trichodina heterodentata Duncan, 1977 was the only trichodinid ciliate species recovered. All tadpoles were naturally infested by T. heterodentata with a mean intensity of 695.14 ± 33.33 trichodinid ciliates per tadpole. A positive correlation was observed between the intensity of the infestation and tadpole weight. Intensity of infestation did not significantly influence mean trichodinid diameter in the populations studied. This is the first study investigating density-dependent effects in interspecific interactions between trichodinids and anurans.

  10. Biomarker Analysis of American Toad (Anaxyrus Americanus) and Grey Tree Frog (Hyla Versicolor) Tadpoles Following Exposure to Atrazine

    Science.gov (United States)

    To better understand the mode of action of atrazine in amphibians, we utilized mass spectrometry-based metabolomics to investigate the biochemical changes in two species of larval amphibians exposed to atrazine. Our objectives were to 1) Use changes in endogenous metabolites to f...

  11. 76 FR 70479 - Draft Environmental Assessment and Safe Harbor Agreement for the Houston Toad Within Nine Texas...

    Science.gov (United States)

    2011-11-14

    ... types that occur on the portion of the property to be enrolled, including ] accurate descriptions of vegetation, water features, and soil types; (4) current land use practices and existing development; and (5.... Box 1306, Albuquerque, New Mexico 87103 (505) 248-6651). SUPPLEMENTARY INFORMATION: Under a...

  12. Comparative pathology and ecological implications of two myxosporean parasites in native Australian frogs and the invasive cane toad.

    Directory of Open Access Journals (Sweden)

    Ashlie Hartigan

    Full Text Available Myxosporean parasites Cystodiscus axonis and C. australis are pathogens of native and exotic Australian frog species. The pathology and ecological outcomes of infection with these parasites were investigated in this study. Gliosis was correlated to Cystodiscus axonis plasmodia in the brains of (9/60 tadpoles and (3/9 adult endangered Green and golden bell frogs using ordinal regression. Severe host reactions to C. axonis (haemorrhage, necrosis, and vasulitis were observed in the brains of threatened Southern bell frogs (8/8, critically endangered Booroolong frogs (15/44 and Yellow spotted bell frogs (3/3. Severe brain lesions were associated with behavioural changes, neurological dysfunction, and spontaneous death. Both C. axonis and C. australis develop in the bile ducts of tadpoles, the plasmodia were significantly associated with biliary hyperplasia, inflammation and the loss of hepatocytes in (34/72 Green and golden bell frog tadpoles using ordinal regression. These lesions were so severe that in some cases 70% of the total liver was diseased. Normal liver function in tadpoles is necessary for metamorphosis, metabolism, and immune function. We postulate that this extensive liver damage would have significant host health impacts. Severe hepatic myxosporidiosis was more prevalent in tadpoles examined in autumn and winter (overwintered, suggestive of delayed metamorphosis in infected tadpoles, which would have serious flow-on effects in small populations. We compared the sensitivity of histopathology and species-specific PCR in the detection of C. australis and C. axonis. PCR was determined to be the most sensitive method (detection limit 1 myxospore equivalent of ribosomal DNA. Histology, however, had the advantage of assessing the impact of the parasite on the host. It was concluded that these parasites have the potential for significant ecological impacts, because of their high prevalence of infection and their ability to cause disease in some frogs.

  13. Tribulations of a prostate cancer trial - lessons learned from TOAD, a cancer council Victoria and Transtasman Radiation Oncology Group Trial

    International Nuclear Information System (INIS)

    Full text: From 2004-2009 a total of 226 out of a target of 750 prostate cancer patients have been randomised into the Timing of Androgen Deprivation trial between immediate and delayed androgen deprivation. A screening log was kept by participating centres for the first 928 patients, which documented the reasons for non-entry into the trial; 42.7% of screened patients were ineligible and a further 33.0% were not entered for other reasons. Fewer than 10% of patients cited not wanting to be part of a clinical trial as a reason for non-entry. Strategies to improve recruitment included broadening the eligibility criteria, encouraging international collaboration, the use and support of research nurses in the private health care environment, and the use of phone follow-up. Recruitment will be completed at the number originally intended to inform the interim analysis designed to test the validity of the statistical assumptions, and a combined survival analysis with the Canadian study is planned.

  14. Mechanisms of adreno- and cholinoreceptors in isolated pulmonary and systemic vasculature of the cane toad (Rhinella marina)

    DEFF Research Database (Denmark)

    Pedersen, Pil Birkefeldt Møller; Wang, Tobias; Brøndum, Emil Toft

    While the overall autonomic regulation of the heart and vasculature of anurans has been studied in some detail, little is known about the role of the adreno- and cholinoreceptors in smooth muscle when looking at resistance in the pulmonary and systemic vessels. Vascular smooth muscle is the primary...... site of regulation of resistance and therefore holds the capacity to control blood flow and pressure. This vascular control allows amphibians to regulate their shunt, i.e. partially bypassing either the pulmonary or systemic circuit. Shunting in amphibians has been studied due to their multiple...... respiratory modalities and their ontogeny including fundamental morphological changes during metamorphosis. Here we use wire myography to evaluate how the vascular tone of isolated blood vessels from the pulmocutaneous, pulmonary, cutaneous and systemic segments respond to sympathetic and parasympathetic...

  15. Morphology, molecular genetics, and bioacoustics support two new sympatric Xenophrys toads (Amphibia: Anura: Megophryidae) in southeast China.

    Science.gov (United States)

    Wang, Yingyong; Zhao, Jian; Yang, Jianhuan; Zhou, Zhixin; Chen, Guoling; Liu, Yang

    2014-01-01

    Given their recent worldwide declines and extinctions, characterization of species-level diversity is of critical importance for large-scale biodiversity assessments and conservation of amphibians. This task is made difficult by the existence of cryptic species complexes, species groups comprising closely related and morphologically analogous species. The combination of morphology, genetic, and bioacoustic analyses permits robust and accurate species identification. Using these methods, we discovered two undescribed Xenophrys species, namely Xenophrys lini sp. nov. and Xenophrys cheni sp. nov. from the middle range of Luoxiao Mountains, southeast China. These two new species can be reliably distinguished from other known congeners by morphological and morphometric differences, distinctness in male advertisement calls, and substantial genetic distances (>3.6%) based on the mitochondrial 16s and 12s rRNA genes. The two new species, together with X. jinggangensis, are sympatric in the middle range of Luoxiao Mountains but may be isolated altitudinally and ecologically. Our study provides a first step to help resolve previously unrecognized cryptic biodiversity and provides insights into the understanding of Xenophrys diversification in the mountain complexes of southeast China. PMID:24714161

  16. Widespread occurrence in frogs and toads of skin compounds interacting with the ouabain site of Na+, K+-ATPase.

    Science.gov (United States)

    Flier, J; Edwards, M W; Daly, J W; Myers, C W

    1980-05-01

    Amphibians of the family Bufonidae contain high levels of skin compounds that both inhibit Na+- and K+-dependent adenosinetriphosphatase and antagonize the binding of ouabain to the enzyme. In species of Bufo and Atelopus, these compounds are relatively nonpolar bufodienolides, whereas Dendrophryniscus and Melanophryniscus contain more polar compounds of unknown structure. Skin extracts from 30 of 48 species of frogs representing an additional eight families contained relatively low levels of compounds that inhibit binding of ouabain to Na+,K+-adenosinetriphosphatase. The widespread occurrence of low levels of inhibitory compounds is consonant with the role for these compounds as physiological regulators of Na+,K+-adenosinetriphosphatase in amphibian skin; high levels in the Bufonidae probably also serve as a defense against some predators. PMID:6245447

  17. Nuclear and mitochondrial phylogeography of the European fire-bellied toads Bombina bombina and Bombina variegata supports their independent histories

    Czech Academy of Sciences Publication Activity Database

    Fijarczyk, A.; Nadachowska, K.; Hofman, S.; Litvinchuk, S.N.; Babik, W.; Stuglik, M.; Gollmann, G.; Choleva, Lukáš; Cogalniceanu, D.; Vukov, T.; Dzukic, G.; Szymura, J. M.

    2011-01-01

    Roč. 20, č. 16 (2011), s. 3381-3398. ISSN 0962-1083 Institutional research plan: CEZ:AV0Z50450515 Keywords : Bombina * isolation with migration * nuclear and mitochondrial markers Subject RIV: EH - Ecology, Behaviour Impact factor: 5.522, year: 2011

  18. Wyoming toad, Bufo hemiophrys baxteri, habitat use and hibernaculum research project with the use of telemetry : Annual report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual report is on a two year study, started in 1998, to evaluate the daily and seasonal habitat use to determine the location of the hibemaculum of the...

  19. Responses on toad tadpoles to ammonium nitrate fertilizer and predatory stress: differences between populations on a local scale

    OpenAIRE

    Ortíz-Santaliestra, Manuel E.; Fernández-Benéitez, María José; Lizana, Miguel; Marco, Adolfo

    2011-01-01

    — Agriculture-related pollution is among the major causes of global amphibian population declines. The multiple stressors to which amphibians are exposed in the field, such as predation pressure, can make agrochemicals far more deadly than when they act in isolation. Even within a small area, diffuse agricultural pollution does not affect all aquatic environments equally, which could account for local differences in amphibian sensitivity to agrochemicals. We examined the combined effects of am...

  20. A Mathematical Model of Solute Coupled Water Transport in Toad Intestine Incorporating Recirculation of the Actively Transported Solute

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Sørensen, Jakob Balslev; Sørensen, Jens Nørkær

    2000-01-01

    A mathematical model of an absorbing leaky epithelium is developed for analysis of solute coupled water transport. The non-charged driving solute diffuses into cells and is pumped from cells into the lateral intercellular space (lis). All membranes contain water channels with the solute passing...... those of tight junction and interspace basement membrane by convection-diffusion. With solute permeability of paracellular pathway large relative to paracellular water flow, the paracellular flux ratio of the solute (influx/outflux) is small (2-4) in agreement with experiments. The virtual solute...... concentration of fluid emerging from lis is then significantly larger than the concentration in lis. Thus, in absence of external driving forces the model generates isotonic transport provided a component of the solute flux emerging downstream lis is taken up by cells through the serosal membrane and pumped...

  1. A new species of Paracapillaria (Nematoda: Capillariidae) from the intestine of the toad Duttaphrynus melanostictus (Anura) from the Malayan Peninsula

    Czech Academy of Sciences Publication Activity Database

    Moravec, František; Modrý, David; Jirků, Miloslav

    2007-01-01

    Roč. 93, č. 4 (2007), s. 907-909. ISSN 0022-3395 R&D Projects: GA ČR(CZ) GA524/06/0170; GA MŠk LC522 Institutional research plan: CEZ:AV0Z60220518 Keywords : Paracapillaria * Duttaphrynus * Malayan Peninsula Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 1.129, year: 2007

  2. The role of common toads in the winter diet of recolonising Eurasian otters (Lutra lutra

    Directory of Open Access Journals (Sweden)

    Pablo García-Díaz

    2011-02-01

    Full Text Available Importanza del rospo comune nella dieta invernale di una popolazione di lontra (Lutra lutra in espansione.
    Tramite analisi dei resti fecali, abbiamo evidenziato il ruolo fondamentale degli anfibi nella dieta invernale della lontra Lutra lutra in stagni artificiali della Spagna nord-occidentale. I numerosi “laghi di cava” presenti nell’area umida di Ribeiras do Louro e Gandaras de Budiño sono stati monitorati nel 2007-2009. Il rospo comune (Bufo bufo era la principale preda della lontra, costituendo l’88% della biomassa consumata, mentre il gambero americano Procambarus clarkii e i pesci erano prede secondarie. I nostri risultati contrastano con la ben nota preferenza della lontra per le rane rispetto al rospo. Il mantenimento della popolazione di lontra nel bacino del fiume Louro dipende strettamente dalla corretta gestione degli stagni artificiali.

  3. Políticas públicas de inclusión en la educación superior los casos de Argentina y Brasil Public policies for inclusion in higher education the Argentinian and Brazilian cases

    Directory of Open Access Journals (Sweden)

    Adriana Chiroleu

    2009-08-01

    Full Text Available Las políticas inclusivas en la educación superior se orientan a lograr que las instituciones contengan una diversidad racial, cultural y sexual semejante a la que existe en el seno de la sociedad, en procura de remediar discriminaciones históricas que han conducido a la situación de desigualdad por la que atraviesan esos grupos. En este sentido, la implementación en algunos países de Políticas de Acción Afirmativa en el ámbito de la educación superior procura una mayor integración social en sociedades caracterizadas por fragmentaciones de diferente naturaleza. En este trabajo nos proponemos abordar desde una perspectiva comparativa los alcances de las políticas públicas de inclusión en la universidad que se desarrollan en Argentina y Brasil, enmarcándolas en los rasgos diferenciales de sus estructuras sociales y sus sistemas de Educación superior.Inclusive policies in higher education are planned to achieve racial, cultural and sexual diversity in institutions, similarly to social diversity itself. Such policies are intended to repair historical discrimination that has contributed to the unequal situation those groups have been facing. For such, the establishment of Affirmative Action Policies in the higher education field in some countries is intended to achieve greater social integration in societies that are usually characterized by fragmentation of different kinds. The purpose of this paper is to address, from a comparative perspective, the advances of public policies for university inclusion in Argentina and Brazil, considering the differences between their social structures and higher education systems.

  4. Políticas públicas de inclusión en la educación superior los casos de Argentina y Brasil Public policies for inclusion in higher education the Argentinian and Brazilian cases

    OpenAIRE

    Adriana Chiroleu

    2009-01-01

    Las políticas inclusivas en la educación superior se orientan a lograr que las instituciones contengan una diversidad racial, cultural y sexual semejante a la que existe en el seno de la sociedad, en procura de remediar discriminaciones históricas que han conducido a la situación de desigualdad por la que atraviesan esos grupos. En este sentido, la implementación en algunos países de Políticas de Acción Afirmativa en el ámbito de la educación superior procura una mayor integración social en s...

  5. ELIAS EN LA 12. UNA APROXIMACIÓN ELIASIANA A LA VIOLENCIA EN EL FÚTBOL EN LA ARGENTINA / Elias in "La 12". An elisian approach to violence in argentinian football.

    Directory of Open Access Journals (Sweden)

    Rodrigo Daskal

    2015-12-01

    Full Text Available En el presente artículo proponemos una reflexión sobre el fenómeno de la violencia en el fútbol, a partir de herramientas conceptuales de la sociología de Norbert Elias. Esta reflexión implica un doble recorrido. Primero indagaremos sobre la relación entre violencia y deporte, en el marco de la concepción de lo que Elias llamó “proceso de la civilización”, para luego analizar los trabajos posteriores que el sociólogo alemán realizó junto a Eric Dunning sobre la particular temática de la violencia en el fútbol. Habiendo desglosado mínimamente estas dos posibilidades, usaremos la experiencia etnográfica para describir las particularidades del fenómeno en el caso argentino, para terminar estableciendo un diálogo entre los datos etnográficos y la mirada eliasiana. AbstractWe propose in these articles to reflect on the phenomenon of violence in Argentine soccer using some conceptual work tools of Norbert Elias. This reflection involves a dual path. First, we will investigate the relationship between violence and sport in the context of conception of what Norbert Elias called the "process of civilization", and then, analyze the subsequent work performed alongside German sociologist Eric Dunning on the particular issue of violence in soccer. Having minimally broken these two possibilities, we will use ethnographic experience to describe the peculiarities of the phenomenon in Argentina, finally establishing a dialogue between the ethnographic data and eliasiana point of view.

  6. Fotografías de indígenas en manuales escolares argentinos: representaciones visuales y connotaciones textuales Photographs of indigenous people in argentinian school textbooks: visual representations and textual connotations

    Directory of Open Access Journals (Sweden)

    María José Saletta

    2012-07-01

    Full Text Available El objetivo de este trabajo es analizar las fotografías de pueblos originarios argentinos utilizadas en manuales escolares de 2o y 3o ciclo publicados por dos editoriales: Santillana y Aique. Se presentan los resultados de un análisis cuantitativo y cualitativo de 93 fotografías correspondientes a 38 manuales publicados entre los anos 2000 y 2005. Se reconoce qué tipo de imágenes son utilizadas, la presencia o no de cultura material autóctona, la utilización de epígrafes y la adscripción étnica de los retratados. Se concluye que existe una representación diferencial a favor de aquellas imágenes que muestran pueblos originarios con su cultura material, pero, al mismo tiempo, una utilización de un lenguaje que emplea términos como "aborigen", que implica un sesgo homogeneizador. Las fotografías son empleadas sólo en su función denotativa, mientras que se deja de lado la connotación visual en privilegio de la textual. La información presente en epígrafes y textos que acompanan a las imágenes no cumple con los requisitos necesarios de precisión y rigurosidad.The aim of this paper is to analyze photographs of native people in Argentinean primary and secondary school textbooks published by two companies, Santillana and Aique. Results from quantitative and qualitative analyses of 93 images taken from 38 school text books published between 2000 and 2005 are presented. Type of image used, presence of autochthonous material culture, use of epigraphs, and the ethnic adscription of the subjects portrayed are analyzed. It is concluded that there is differential representation in favor of those images showing native people with their material culture, although the use of language that contains derogative terms such as "aborigen" (i.e., native people at the same time clearly indicates an homogenizing bias. Images are used mostly denotatively, while textual connotation is privileged over visual connotation. Information on the epigraphs and texts accompanying an image do not fulfill the requirements of thoroughness and accuracy, thus reducing the images to illustrations rather than useful documents.

  7. El basamento cristalino de los Andes norpatagónicos en Argentina: geocronología e interpretación tectónica The Crystalline Basement in the Argentinian North-Patagonian Andes: geochronology and tectonic interpretation

    Directory of Open Access Journals (Sweden)

    Ricardo Varela

    2005-07-01

    Full Text Available Se presentan los resultados obtenidos en el estudio isotópico de rocas del basamento ígneo-metamórfico de los Andes expuesto en Argentina, aproximadamente a los 40°S, en las provincias de Neuquén y Río Negro. Fueron utilizadas metodologías isotópicas, para obtener información sobre la edad de emplazamiento de cuerpos ígneos deformados dúctilmente (U-Pb en circones, tiempo de enfriamiento luego de los procesos ígneos y metamórficos que modelaron a este basamento (K-Ar en micas; U-Pb en titanita y la historia cortical involucrada (Sm-Nd en roca total. No se obtuvieron edades proterozoicas, como lo sugerían anteriores determinaciones Rb-Sr y K-Ar. Los datos definen en la región dos eventos ígneo metamórficos. El más antiguo, conservado en tonalitas y granitos deformados de los alrededores de San Martín de los Andes, tiene edades U-Pb en circones de 420 a 380 Ma (Devónico y edades K-Ar en micas de 375 a 310 Ma. El más joven está bien representado en los afloramientos al sur del Río Limay, desde Paso Flores a Río Chico-Cushamen y tiene edades U-Pb en circones de rocas metaígneas en torno a 280 Ma (Pérmico inferior y edades de enfriamiento en micas próximas a 260-250 Ma. Ambos conjuntos se generaron en ambiente de arco magmático y denotan la acción de dos episodios principales separados por ca. 100 Ma, posibles de relacionar con los Movimientos Chánicos y Gondwánicos, respectivamente. Las edades modelo Sm-Nd T DM, con valores entre 1907 y 1165 Ma, eNd para el momento de cristalización de las rocas de preferencia entre -3,0 y -8,4 y e Nd(0 preferentemente entre -6,9 a -11,9 sugieren reciclado de corteza proterozoica con escasa adición de corteza juvenil durante el PaleozoicoIsotopic data are presented for rocks of the Andean crystalline basement at 40°S, in Neuquén and Río Negro provinces. The methods used were U-Pb in zircon (crystallization ages of plutonic rocks, K-Ar in micas and U-Pb in titanite (metamorphism and cooling ages and Sm-Nd in whole rock (crustal evolution. No Proterozoic ages were obtained as suggested by previous Rb-Sr and K-Ar data, and two different igneous-metamorphic events were identified. The older one is Devonian and exposed in San Martín de los Andes region, according to 420-380 Ma zircon ages and 375-310 Ma ages in micas of deformed tonalitic and granitic rocks. The younger one, in rocks cropping out to the south of Limay River region, is revealed by Early Permian zircon ages (about 280 Ma and Late Permian cooling ages (260-250 Ma of metaigneous rocks. The rocks of both sets were assigned to a magmatic arc environment and correlated respectively with the Chanic orogeny (Devonian; Upper Famatinian Cycle and Gondwanic Cycle (Upper Paleozoic-Triassic. The Sm-Nd T DM model ages, ca.1907-1165 Ma, eNd for the crystallization age of the rocks ca. -3,0 and -8,4 and eNd(0 ca. -6,9-11,9 suggest reworking of continental proterozoic crust with minor addition of juvenile magmas from the mantle during the Paleozoic

  8. Estimación bayesiana de componentes de (covarianza en Brangus argentino para caracteres de res mediante el algoritmo FCG Bayesian estimation of (co variance components in Argentinian Brangus for carcass traits using the FCG algorithm

    Directory of Open Access Journals (Sweden)

    R. J. C. Cantet

    2010-06-01

    Full Text Available Se emplearon los datos de 2273 toritos y vaquillonas Brangus para estimar las heredabilidades (h² y las correlaciones aditivas y ambientales de caracteres de calidad de carne medidos por ultrasonido. Los registros provenían del programa de evaluación genética de la Asociación Argentina de Brangus. Los caracteres medidos fueron el área del ojo del bife (AOB, el marmoreado (MB, la grasa dorsal (GD y la grasa de cadera (GC. La edad media de los animales al momento de la medición fue 641 días en machos y 685 días en hembras. Los parámetros genéticos y ambientales fueron estimados mediante un algoritmo bayesiano conjugado. Los valores estimados de h² fueron 0,22, 0,16, 0,12 y 0,21, para AOB, GD, CC y MB, respectivamente. En términos generales, las estimaciones de las correlaciones genéticas y ambientales se encontraron cercanas a la cifra media de la literatura. Si bien los valores estimados de h² fueron inferiores al promedio de la investigación realizada en vacunos para carne, la variabilidad encontrada es suficiente como para que la respuesta a la selección por estos caracteres - empleando predicciones de los valores de cría calculadas con los parámetros estimados - sea moderadamente efectiva.Data on 2273 Brangus young bulls and heifers were used to estimate heritabilities (h² and genetics and environmental correlations for ultrasound carcass measures. Records were from the genetic evaluation program of Asociación Argentina de Brangus. Traits measured were rib-eye area (AOB, marbling (MB, back-fat thickness (GD, and hip-fat thickness (GC. Average ages of measure were 641 days in males and 685 in females. The genetic and environmental dispersion parameters were estimated by a conjugate Bayesian algorithm (FCG. Estimates of h² were 0,22, 0,16, 0,12, and 0,21, for AOB, GD, CC, and MB, respectively. In general, estimates of genetic and environmental correlations were close to the average published values. Even tough estimates of h² were below the average of published estimates for beef cattle, the additive genetic variation found in the current study would lead to a moderate response to selection - using predictions of breeding value that are calculated with the estimate parameters.

  9. Estimación bayesiana de componentes de (co)varianza en Brangus argentino para caracteres de res mediante el algoritmo FCG Bayesian estimation of (co) variance components in Argentinian Brangus for carcass traits using the FCG algorithm

    OpenAIRE

    Cantet, R. J. C.; A. N. Birchmeier

    2010-01-01

    Se emplearon los datos de 2273 toritos y vaquillonas Brangus para estimar las heredabilidades (h²) y las correlaciones aditivas y ambientales de caracteres de calidad de carne medidos por ultrasonido. Los registros provenían del programa de evaluación genética de la Asociación Argentina de Brangus. Los caracteres medidos fueron el área del ojo del bife (AOB), el marmoreado (MB), la grasa dorsal (GD) y la grasa de cadera (GC). La edad media de los animales al momento de la medición fue 641 día...

  10. Who Owns the Falkland Islands? Background to the Conflict.

    Science.gov (United States)

    Gerlack, Allen

    1982-01-01

    Presents an historical perspective on the current hostilities over the sovereignty of the Falkland Islands. The validity of British and Argentinian claims to the islands is evaluated. The social and political problems which motivated the Argentinian government to reclaim the islands by force are considered. (AM)

  11. Role of Mitochondria-rich Cells for Passive Chloride Transport, discussion of Ussing's Contribution to Our Understanding of Shunt Pathways in Epithelia

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Kristensen, Poul; Nedergaard, Signe Nielsen;

    2001-01-01

    Toad skin, Mitochondria-rich cells, Chloride channels, Epithelial shunt pathways, Leaky epithelia, Recirculation theory of isotonic transport......Toad skin, Mitochondria-rich cells, Chloride channels, Epithelial shunt pathways, Leaky epithelia, Recirculation theory of isotonic transport...

  12. Risk from radionuclides: a frog's perspective : Accumulation of 137Cs in a riparian wetland, radiation doses, and effects on frogs and toads after low-dose rate exposure

    OpenAIRE

    Stark, Karolina

    2006-01-01

    Threats from man-made radionuclides include waste issues, increasing number of power plants, underground bomb testing, nuclear weapons, and “dirty bombs”. Until recently the ionizing radiation protection system focused on protecting humans with an implied protection of biota. However, goals of sustainable development and precautionary principles for human activity are leading to an inclusion of plant and animal populations in the protection system. From this perspective, the present thesis ex...

  13. Scaling new heights: first record of Boulenger’s Lazy Toad Scutiger boulengeri (Amphibia: Anura: Megophryidae from high altitude lake in Sikkim Himalaya, India

    Directory of Open Access Journals (Sweden)

    Barkha Subba

    2015-08-01

    Full Text Available Frogs in the genus Scutiger of the family Megophryidae are the highest altitude frogs in the world, and are endemic to eastern Himalaya. Here, we report the occurrence of Scutiger boulengeri (Bedriaga, 1898 in one of the highest altitude lakes in the world, Lake Gurudongmar. This is the first report of Scutiger boulengeri from India and the first record of any amphibian species to be found at an altitude as high as 5270m, thus setting a world record for the highest altitude frog. Scutiger sikimmensis (Blyth, 1855 is another species of the genus Scutiger found in this region. This species is often confused with Scutiger boulengeri due to similar morphology and habitat overlap. We provide a detailed account of both S. boulengeri and S. sikimmensis based on morphology and molecular identification techniques. 

  14. Membrane potentials and intracellular Cl- activity of toad skin epithelium in relation to activation and deactivation of the transepithelial Cl- conductance

    DEFF Research Database (Denmark)

    Willumsen, N J; Larsen, Erik Hviid

    1986-01-01

    independent of whether the external bath was NaCl-Ringer's, NaCl-Ringer's with amiloride, KCl-Ringer's or choline Cl-Ringer's. To partition the routes of the conductive Cl- ion flow, we measured in the isolated epithelium with double-barrelled microelectrodes apical membrane potential. Va, and intracellular...... Cl- activity, acCl, of the principal cells identified by differential interference contrast microscopy. Under short-circuit conditions, Isc = 27.0 +/- 2.0 microA/cm2, with NaCl-Ringer's bathing both surfaces, Va was -67.9 +/- 3.8 mV (mean +/- SE, n = 24, six preparations) and acCl was 18.0 +/- 0.9 m...... V was stepped back to 40 mV, Va instantaneously shifted to -67.8 +/- 3.9 mV while acCl and fRa remained constant during deactivation of GCl. Similar results were obtained in epithelia impaled from the serosal side. In 12 skins from animals adapted to either tap water or distilled water the density...

  15. Geographic variation in Incilius occidentalis (Anura: Bufonidae), an endemic toad from Mexico, with a redescription of the species and delimitation of the type locality

    OpenAIRE

    Georgina Santos-Barrera

    2014-01-01

    A taxonomic revision of the populations referable to the wide ranging species Incilius occidentalis was conducted based on 10 morphometric variables and other external morphological traits. Thirty three populations were geographically defined from more than 220 locality records of the species. A brief summary of the nomenclatural history of this species is presented and the external morphological variation is analyzed. Incilius occidentalis is here redescribed on the basis of comparisons with...

  16. Historical biogeography resolves the origins of endemic Arabian toad lineages (Anura: Bufonidae): Evidence for ancient vicariance and dispersal events with the Horn of Africa and South Asia

    OpenAIRE

    Portik, Daniel M; Papenfuss, Theodore J.

    2015-01-01

    Background The Arabian Peninsula is home to a unique fauna that has assembled and evolved throughout the course of major geophysical events, including the separation of the Arabian Plate from Africa and subsequent collision with Eurasia. Opportunities for faunal exchanges with particular continents occurred in temporally distinct periods, and the presence of African, Western Eurasian, and South Asian derived taxa on the Arabian Peninsula signifies the complexity of these historical biogeograp...

  17. Exploring the Genetic Basis of Adaptation to High Elevations in Reptiles: A Comparative Transcriptome Analysis of Two Toad-Headed Agamas (Genus Phrynocephalus)

    Science.gov (United States)

    Yang, Weizhao; Qi, Yin; Fu, Jinzhong

    2014-01-01

    High elevation adaptation offers an excellent study system to understand the genetic basis of adaptive evolution. We acquired transcriptome sequences of two closely related lizards, Phrynocephalus przewalskii from low elevations and P. vlangalii from high elevations. Within a phylogenetic framework, we compared their genomic data along with green anole, chicken and Chinese softshell turtle, and identified candidate genes and functional categories that are potentially linked to adaptation to high elevation environments. More than 100 million sequence reads were generated for each species via Illumina sequencing. A de novo assembly produced 70,919 and 62,118 transcripts for P. przewalskii and P. vlangalii, respectively. Based on a well-established reptile phylogeny, we detected 143 positively selected genes (PSGs) along the P. vlangalii lineage from the 7,012 putative orthologs using a branch-site model. Furthermore, ten GO categories and one KEGG pathway that are over-represented by PSGs were recognized. In addition, 58 GO categories were revealed to have elevated evolutionary rates along the P. vlangalii lineage relative to P. przewalskii. These functional analyses further filter out PSGs that are most likely involved in the adaptation process to high elevations. Among them, ADAM17, MD, and HSP90B1 likely contributed to response to hypoxia, and POLK likely contributed to DNA repair. Many other candidate genes involved in gene expression and metabolism were also identified. Genome-wide scan for candidate genes may serve as the first step to explore the genetic basis of high elevation adaptation. Detailed comparative study and functional verification are needed to solidify any conclusions. High elevation adaptation requires coordinated changes in multiple genes that involve various physiological and biochemical pathways; we hope that our genetic studies will provide useful directions for future physiological or molecular studies in reptiles as well as other poikilothermic species. PMID:25386640

  18. A new genus of Toads (Amphibia: Anura: Bufonidae) from the Pacific Slopes of the Andes in Northern Ecuador and Southern Colombia, with the description of two new species

    NARCIS (Netherlands)

    Hoogmoed, M.S.

    1985-01-01

    The genus Andinophryne, characterized by the presence of an omosternum, an externally visible tympanum, elongate parotoids and extensively webbed hands and feet is described from the Pacific versant of the Andes in northwestern Ecuador and southwestern Colombia. Two new species, Andinophryne colomai

  19. Effect of Uncaria rhynchophyla Mig.jackas on the heart of toad%钩藤对蟾蜍心脏的作用机制研究

    Institute of Scientific and Technical Information of China (English)

    唐省三

    2002-01-01

    目的:探讨钩藤对蟾蜍心脏的作用.方法:用钩藤灌流蟾蜍心脏,观察灌流前后心肌收缩力、心输出量和心率的变化.结果心肌收缩幅度减小、心输出量减少和心率变慢.结论:钩藤对蟾蜍心脏有抑制作用,从而降低血压.

  20. Range extension of Ferguson Toad Duttaphrynus scaber (Schneider (Amphibia: Anura: Bufonidae up to the northern most limit of Western Ghats, with its advertisement call analysis

    Directory of Open Access Journals (Sweden)

    A. Padhye

    2013-07-01

    Full Text Available Duttaphrynus scaber (Schneider is known to occur in the southern Western Ghats, Eastern Ghats and northeastern India. However, there is no report of its occurrence from the northern Western Ghats from the states of Maharashtra and Gujarat. Here we report the occurrence of this species from the northernmost limit of the Western Ghats, a substantial range extension (approx. 550km from the nearest known locality. We confirm our identification on the basis of morphology by comparing our specimens with a previously collected Duttaphrynus scaber specimen from Thrissur in Kerala State as well as on the molecular basis. Analysis based on the advertisement call of Duttaphrynus scaber, albeit preliminary, is provided for the first time for this species.

  1. On-line comprehensive two-dimensional normal-phase liquid chromatography×reversed-phase liquid chromatography for preparative isolation of toad venom.

    Science.gov (United States)

    Li, Jia-Fu; Fang, Hua; Yan, Xia; Chang, Fang-Rong; Wu, Zhen; Wu, Yun-Long; Qiu, Ying-Kun

    2016-07-22

    An on-line comprehensive preparative two-dimensional normal-phase liquid chromatography×reversed-phase liquid chromatography (2D NPLC×RPLC) system was constructed with a newly developed vacuum evaporation assisted adsorption (VEAA) interface, allowing fast removal of NPLC solvent in the vacuum condition and successfully solving the solvent incompatibility problem between NPLC and RPLC. The system achieved on-line solvent exchange within the two dimensions and its performance was illustrated by gram-scale isolation of crude extract from the venom of Bufo bufo gargarizans. Within separation time of ∼20h, 19 compounds were obtained with high purity in a single run. With the VEAA interface, the 2D system exhibited apparent advantages in separation efficiency and automation compared with conventional methods, indicating its promising application in the routine separation process for complicated natural products. PMID:27328884

  2. A Suspected Parasite Spill-Back of Two Novel Myxidium spp. (Myxosporea) Causing Disease in Australian Endemic Frogs Found in the Invasive Cane Toad

    Czech Academy of Sciences Publication Activity Database

    Hartigan, A.; Fiala, Ivan; Dyková, Iva; Jirků, Miloslav; Okimoto, B.; Rose, K.; Phalen, D. N.; Šlapeta, J.

    2011-01-01

    Roč. 6, č. 4 (2011), e18871. E-ISSN 1932-6203 R&D Projects: GA AV ČR KJB600960701 Grant ostatní: GA ČR(CZ) GP204/09/P519 Institutional research plan: CEZ:AV0Z60220518 Keywords : EW-SOUTH-WALES * BUFO-MARINUS * BIOLOGICAL INVASIONS * INFECTIOUS-DISEASES * NORTH-AMERICA * TREE FROG * MYXOZOA * SEQUENCES * PHYLOGENY * ECOLOGY Subject RIV: EG - Zoology Impact factor: 4.092, year: 2011

  3. Lino Baranao, President of the National Agency for the Promotion of Science and Technology in Argentina, toured the ATLAS experiment's underground cavern during his visit to CERN on 9 May

    CERN Multimedia

    Patrice Loïez

    2005-01-01

    Picture 01 : Here he is seen with ATLAS spokesperson, Peter Jenni (left), and the ATLAS Muon System project leader, Giora Mikenberg, listening to Karina Loureiro (right), an Argentinian student at the University of Wisconsin

  4. The Need for Training in the Metal Recycling Industry

    International Nuclear Information System (INIS)

    This paper describes the experiences of an Argentinian steelmaking company in installing and operating equipment for detecting radioactive material in scrap metal. The lessons learned and the improvements made on the basis of the experience gained are documented. (author)

  5. Spent fuel management in Argentina

    International Nuclear Information System (INIS)

    The general program on Argentinian Spent Fuel Management has been presented in the previous meeting. This presentation includes an updating of the programs and a short description of the mixed oxide rods pilot plant. (author). 1 fig., 5 photographs

  6. Spent fuel management in Argentina

    International Nuclear Information System (INIS)

    The general program on Argentinian Spent Fuel Management has been informed in previous meetings and IAEA publications. This presentation includes an updating of the programs and a short description of the dry storage of Embalse NPP spent fuel. (author)

  7. ABACC ten years applying safeguards

    International Nuclear Information System (INIS)

    The Argentinian-Brazilian Agency for Accounting and Control of nuclear special materials has been in operations for ten years. The rational behind the creation and the work performed by the Agency during the last decade is described. (author)

  8. Gastronomie Argentiny

    OpenAIRE

    Cypriánová, Michaela

    2015-01-01

    The aim of this thesis is to characterize Argentinian gastronomy with emphasis on regional differences and also to ascertain a situation of representation of Argentinian gastronomy in Prague. The thesis is divided into six chapters where the first two chapters deal with the theoretical background, namely the importance of tourism and gastronomy and their mutual relationship and also a description of the locality of Argentina from the point of view of geographical, demographical, historical an...

  9. The structure of zetekitoxin AB, a saxitoxin analog from the Panamanian golden frog Atelopus zeteki: A potent sodium-channel blocker

    OpenAIRE

    Yotsu-Yamashita, Mari; Yong H Kim; Dudley, Samuel C.; Choudhary, Gaurav; Pfahnl, Arnold; Oshima, Yasukatsu; Daly, John W.

    2004-01-01

    Bufonid anurans of the genus Atelopus contain both steroidal bufadienolides and various guanidinium alkaloids of the tetrodotoxin class. The former inhibit sodium-potassium ATPases, whereas the latter block voltage-dependent sodium channels. The structure of one guanidinium alkaloid, zetekitoxin AB, has remained a mystery for over 30 years. The structure of this alkaloid now has been investigated with a sample of ≈0.3 mg, purified from extracts obtained decades ago from the Panamanian golden ...

  10. Infancia, dibujos animados y televisión pública. La difusión de valores y contravalores en la producción española y argentina Childhood, cartoons and public television. The diffusion of the values and disvalues in the Spanish and Argentinian production

    Directory of Open Access Journals (Sweden)

    Gabriela Fabbro

    2016-01-01

    Full Text Available La exposición a los medios 'cultiva' la forma de comprender el mundo asentando creencias, representaciones mentales y actitudes que llegan a modificar la concepción de la realidad. Ante esta situación, la audiencia infantil es la que más interesa ya que consume productos audiovisuales en un momento de formación en la que preocupa qué ven en televisión y cómo lo interpretan. Por ello, y por ser un público vulnerable que aprende y aprehende lo que les viene impuesto, el objetivo de este trabajo es comprobar el compromiso de la televisión pública en España y Argentina por producir contenidos adecuados para los niños y niñas. Mediante una metodología cualitativa, y usando como herramienta de abordaje el análisis de contenido, se ha podido demostrar que ambos países difunden programas infantiles basados en valores. Aunque este trabajo tiene las limitaciones propias de un diseño experimental basado en un número de observaciones limitadas, los resultados son relevantes para demostrar que desde la perspectiva del discurso televisivo como informador y formador, la televisión pública de ambos países contribuye al enriquecimiento cognitivo de los niños y niñas que los consume, potenciando así la educación en valores. The media exposure ‘cultivate’ the way to understand the world by setting beliefs, mental representations and attitudes that change the conception of reality. In this situation, childish audience is the most interesting one because it consumes audiovisual products in a formative stage in which it worries what they watch on TV and how they interpret it. By then, being a vulnerable audience that learn and apprehend what is imposed to them, the aim of this study is to confirm the agreement of the public television in Spain and Argentina to produce suited contents for children. By a qualitative methodology, and by using the analysis of content as a tool, it has been shown that both countries broadcast children programmes based on values. Although this study has its own limitations of experimental design based on a limited number of observations, the results are important for demonstrating that from the perspective of the television speech as reporter and former, public television of both countries contribute to children’s cognitive knowledge that consume it, strengthening to education on values.

  11. Les « clubs de troc » argentins : un microcosme monétaire Credito dépendant du macrocosme Peso The Argentinian Barter clubs: a monetary microcosm Credito dependent of the monetary macrocosm Peso Los clubes de trueque argentinos: un microcosmos monetario. Crédito dependiente del macrocosmos Peso

    Directory of Open Access Journals (Sweden)

    Pepita Ould-Ahmed

    2010-06-01

    Full Text Available Cet article s’intéresse à un cas concret de système monétaire local, celui des « clubs de troc » développés en Argentine à partir de 1995. Contrairement à ce que leur nom laisse penser, les « clubs de troc » désignent des espaces marchands communautaires, à l’intérieur desquels les transactions économiques sont réglées en credito, monnaie-papier interne et non convertible avec la monnaie officielle. La question que pose ce type d’expérience monétaire parallèle est de savoir pourquoi et sous quelles conditions cette monnaie privée non convertible avec la monnaie officielle parvient à être acceptée. Est-ce que ce micro-système monétaire peut fonctionner de manière indépendante et cloisonnée, ou bien a-t-il besoin de nouer des rapports avec le macro-système monétaire officiel ? Telles sont les questions auxquelles cet article se propose de répondre.This paper examines a concrete case of local currency systems, the Argentine “barter clubs” developed from 1995. “Barter club” denotes a place of market exchange, within which economic transactions are paid for using an internal paper currency, the “credito”, issued by the founders of these clubs and not convertible with the official currency. Its starting point is to wonder why and under what conditions this private currency, non-convertible with the official currency, is accepted. Could this micro-monetary system operate in an insular and independent manner, or was it necessary to establish some kind of relation with the official macro-monetary system? These are the questions that this article sets out to answer.Este artículo se interesa sobre un caso concreto del sistema monetario local, el de los “clubes de trueque”, desarrollados en Argentina a partir de 1995. Contrariamente a lo que su nombre deja pensar, los “clubes de trueque” designan los espacios comerciales comunitarios, al interior de los cuales las transacciones económicas son reguladas mediane créditos, moneda papel interna y no convertible con la moneda official, que llegan a ser aceptados. En ese micro sistema monetario ¿puede funcionar de manera independiente y encapsulada, o tienen necesidad de establecer relaciones con el macro sistema monetario official? Tales son las cuestiones a las cuales este artículo se propone responder.

  12. El rol de la dirigencia política argentina en la promoción de un nuevo patrón de relaciones internacionales en la década de los noventa | The role of the political argentinian ruling class in the promotion of a new international relations pattern

    Directory of Open Access Journals (Sweden)

    María Cecilia MÍGUEZ

    2010-10-01

    Full Text Available En este artículo se analiza el rol de la dirigencia política argentina en la adopción de las reformas neoliberales en los inicios de la década de los noventa. En especial,  estudia una etapa de transición (1987-1991 hacia un consenso entre los dos partidos mayoritarios del sistema político respecto de la adopción de las reformas neoliberales, que profundizaron una inserción internacional dependiente. Se analizarán las posiciones de la Unión Cívica Radical y del Partido Justicialista respecto de tres dimensiones de la política exterior y de la política económica doméstica en dicho período, y las condiciones de gestación de dicho consenso.This article analyzes the role of Argentina’s political leadership in the adoption of neoliberal reforms in the early nineties. In particular, studies the formation of a consensus between the two major parties of the political system on foreign policy, in its various dimensions, which made possible the deepening of international integration dependent. It will analyze the structural and economic conditions of that consensus gestation and their specific content.

  13. Comportamiento de reubicación del alimento de Eucranium, escarabajo estercolero endémico de la Argentina y comparación con Scarabaeus (Pachysoma del sudoeste de África (Coleoptera: Scarabaeidae: Scarabaeinae Food relocation and nesting behavior of the Argentinian dung beetle genus Eucranium and comparison with the southwest African Scarabaeus (Pachysoma (Coleoptera: Scarabaeidae: Scarabaeinae

    Directory of Open Access Journals (Sweden)

    Federico C. Ocampo

    2005-07-01

    Full Text Available Se describe el comportamiento de reubicación del alimento del género sudamericano Eucranium Brullé basado en observaciones en su ambiente natural. La preferencia de alimento, el modo de transportarlo, preferencia de hábitat, y período de actividad en la superficie son discutidos para dos especies: E. arachnoides Brullé y E. planicolle Burmeister. La biología y comportamiento de relocación del alimento de Eucranium es comparado con la biología y comportamiento del subgénero del sudoeste de África Scarabaeus (Pachysoma MacLeay, el cual es similar morfológicamente. La convergencia adaptativa a los ambientes áridos de Eucranium y S. (Pachysoma son discutidas.The food relocation and nesting behavior of the South American genus Eucranium Brullé is described based on observations carried out under natural conditions. Food preference, food transportation, period of surface activity, and habitat preference are described for two species, E. arachnoides Brullé and E. planicolle Burmeister. The biology and food relocation behavior of Eucranium is compared with that of the morphologically similar South African subgenus Scarabaeus (Pachysoma MacLeay. The convergent adaptations to psamophilous habitats of Eucranium and S. (Pachysoma are discussed.

  14. GARGANTA SECA Y ARENA EN LAS BOTAS: PROSPECTANDO ANTECEDENTES ARQUEOLÓGICOS DE LAS TIERRAS ÁRIDAS DEL NORESTE MENDOCINO (CENTRO OESTE ARGENTINO (Dry throat and sand in the boots: Prospecting archaeological backgrounds of the Mendoza Northeastern drylands, Argentinian Center South

    Directory of Open Access Journals (Sweden)

    Horacio Chiavazza

    2009-03-01

    Full Text Available Aquí se presenta un detallado estado de las investigaciones arqueológicas desarrolladas en el noreste de la provincia argentina de Mendoza. Esta zona es objeto de estudios desde principios del siglo XX. Sin embargo los pulsos de la investigación han registrado etapas de abandono total y de intervenciones selectivas. Los investigadores han partido de los trabajos precedentes para explicar por extensión las modalidades de asentamiento en la totalidad del territorio norte y, sobre todo, del occidente montañoso, que era donde concentraban sus campañas. Esto acabó generando un cuadro de antecedentes desequilibrado y superficial en el conocimiento de dicha área, con implicaciones en el cuadro interpretativo general de la prehistoria local. En este caso, indagamos las posibles causas que dieron lugar a tal proceso, sus vínculos con los enfoques teóricos y metodologías dominantes a lo largo del siglo XX y su relación con la selección de zonas para llevar a cabo estudios de campo en el norte de la provincia. Reflexionamos críticamente sobre los alcances, límites y posibilidades que ofrece la región para profundizar los análisis arqueológicos del poblamiento prehispánico en relación con las condiciones del ambiente y los procesos históricos documentados, proponiendo discutir los enfoques que basan sus explicaciones en hechos dados por sentados y que merecerían antes una discusión en base a la evidencia disponible. ENGLISH: Here is a detailed state of archaeological research developed in the northeastern Argentine province of Mendoza. This area is the subject of studies since the early twentieth century. However, the pulses of the investigation have been stages of total abandonment and selective interventions. This ended up creating an unbalanced picture of history and superficial knowledge of that area, with implications for the general picture of prehistory interpreted locally. In this case, we investigate the possible causes leading to this process, their ties with the dominant theoretical approaches and methodologies throughout the twentieth century and their relationship with the selection of areas to conduct field studies in northern province. We reflect critically on the scope, limits and possibilities of the region for further archaeological analysis of prehistoric settlement to discuss approaches that base their explanations on facts taken for granted and which deserve before a discussion based on the evidence available.

  15. La Dimensión Global y Sexual de la Ciudadanía en América Latina y los Derechos Humanos- El Caso Argentino (The Global and Sexual Aspects of Citizenship and Human Rights in Latin America: The Argentinian Case

    Directory of Open Access Journals (Sweden)

    Maria Luisa Bartolomei

    2015-06-01

    Full Text Available The paper discusses the issue of sexual violence against women during the past military dictatorships in Latin America, especially in Argentina, and some consequences in the current practice of their sexual and reproductive rights. It analyzes the extent the exercise of sexuality has a connection with the exercise of power, which organizes, manages, and prioritizes behavior depending on a political, social and cultural project, in a context of time and space. This means that the public and private, power and sexuality depend on the idea of the nation, class, race and religion, and consequently implies the political control of reproduction and the family model, including expressions of gender sexual violence. The paper discusses feminist theoretical concepts, such as the concept of gender and nation from an intersectional perspective (Yuval Davis, the idea of post colonialism and decolonization of feminism (Mohanty, and the relationship between gender and globalization (Fraser. Este artículo debate el tema de la violencia sexual contra las mujeres durante las últimas dictaduras militares en América Latina, especialmente el caso argentino y sus efectos en el ejercicio actual de los derechos sexuales. En él se analiza cómo el ejercicio de la sexualidad tiene una relación con el poder, el cual organiza, gestiona, y jerarquiza conductas según un proyecto político, social y cultural, en un contexto determinado. Lo público y lo privado, el poder y la sexualidad en relación a los conceptos de patria, clase, raza y religión, y con ello el control político de la reproducción y del modelo de familia, y de la violencia sexual. En el análisis se discuten concepciones teóricas feministas, como el concepto de género y nación desde la perspectiva interseccional de Yuval Davis, la idea de postcolonialidad y descolonización del feminismo de Mohanty, y la relación entre género y globalización de Fraser. DOWNLOAD THIS PAPER FROM SSRN: http://ssrn.com/abstract=2611061

  16. ESTIMACIÓN DE LA INGESTA POTENCIAL DE ÁCIDO ETILENDIAMINOTETRAACÉTICO EN NIÑOS Y ADOLESCENTES ARGENTINOS, INFLUENCIA DE LA FORTIFICACIÓN DE CEREALES PARA DESAYUNO CON SAL FÉRRICA DE ESTE ÁCIDO POTENTIAL ETHYLENEDIAMINETETRAACETIC ACID INTAKE IN ARGENTINIAN CHILDREN AND ADOLESCENTS, INFLUENCE OF BREAKFAST CEREAL FORTIFICATION WITH THE FERRIC SALT OF THIS ACID

    OpenAIRE

    Carolina Cagnasso E; Laura López B; Viviana Rodríguez G; Mirta Valencia E

    2007-01-01

    Diversas organizaciones promueven el uso de la sal férrica del ácido etilendiaminotetraacético (FeNaEDTA) como fortificante en países con alta prevalencia de anemia ferropénica. Debido a que el ácido etilendiaminotetraacético (EDTA) se utiliza en alimentos como aditivo y posee una Ingesta Diaria Admisible de 2,5 mg/kg se estimó su consumo en niños y adolescentes frente a la posibilidad de la utilización de FeNaEDTA como fortificante. Además se evaluó la influencia que tendría el aporte de EDT...

  17. Chloroform fumigation-extraction labile C pool (microbial biomass C "plus" shows high correlation to microbial biomass C in Argentinian and Brazilian soils Alta correlación entre el "pool" de carbono lábil por fumigación con cloroformo-extracción (carbono de biomasa microbiana plus y carbono de biomasa microbiana en suelos de Argentina y Brasil

    Directory of Open Access Journals (Sweden)

    Helvécio De-Polli

    2007-07-01

    Full Text Available Chloroform fumigation-incubation and chloroform fumigation-extraction approaches have significantly contributed to assess soil microbial biomass. Some controversy is found in the literature about the suggestion to calculate microbial biomass carbon (MBC without the subtraction of the un-fumigated control, in opposition to the originally proposed method that requires such subtraction. Some authors consider the non-subtraction proceeding as a more robust method. Nevertheless, values obtained without subtraction of a control include other labile organic fractions of soil carbon besides microbial biomass. Therefore, due to the usefulness of this measurement we consider more appropriate to call it as chloroform-fumigation labile C pool or microbial biomass carbon "plus" (MBC PLUS. We used a vast series of data from soils of Argentina and Brazil under different management situations to verify whether MBC correlates to MBC PLUS. There was a significant statistical correlation between values of MBC obtained by fumigation-extraction method and the corresponding MBC PLUS. The MBC PLUS performed as well as MBC as an indicator to differentiate soil managements and their impact on soil quality.Los métodos de fumigación-incubación y fumigación extracción han contribuido significativamente a las determinaciones de biomasa microbiana del suelo. En la literatura se encuentran algunas controversias acerca de la sugerencia de calcular el carbono de biomasa microbiana (CBM sin la sustracción del control no fumigado, en oposición a las metodologías tradicionales que requieren de dicha sustracción. Algunos autores mencionan que el hecho de no realizar la sustracción hace al procedimiento más robusto. Sin embargo, los valores obtenidos sin la sustracción del control incluyen otras fracciones lábiles del carbono, además de la biomasa microbiana. Debido a lo útil que resulta esta medida consideramos adecuado llamarla "pool" de carbono lábil por fumigación con cloroformo o carbono de biomasa microbiana "plus" (CBM PLUS. Usamos una amplia serie de datos de suelos de Argentina y Brasil bajo diferentes situaciones de manejo para verificar si el CBM correlaciona con el CBM PLUS. Hubo una correlación estadísticamente significativa entre los valores de CBM obtenidos por el método de fumigación-extracción y los correspondientes a CBM PLUS. Este se vislumbra, al igual que el CBM, como un indicador para diferenciar situaciones de manejo de suelos y el impacto sobre su calidad.

  18. Range extension of Ferguson Toad Duttaphrynus scaber (Schneider) (Amphibia: Anura: Bufonidae) up to the northern most limit of Western Ghats, with its advertisement call analysis

    OpenAIRE

    A. Padhye; Pandit, R.; Patil, R; S Gaikwad; N. Dahanukar; Y. Shouche

    2013-01-01

    Duttaphrynus scaber (Schneider) is known to occur in the southern Western Ghats, Eastern Ghats and northeastern India. However, there is no report of its occurrence from the northern Western Ghats from the states of Maharashtra and Gujarat. Here we report the occurrence of this species from the northernmost limit of the Western Ghats, a substantial range extension (approx. 550km) from the nearest known locality. We confirm our identification on the basis of morphology by comparing our spec...

  19. Tissue kinetics, ion transport, and recruitment of mitochondria-rich cells in the skin of the toad (Bufo bufo) in response to exposure to distilled water

    DEFF Research Database (Denmark)

    Budtz, Poul Egede; Christoffersen, Betina C.; Johansen, Jesper S.; Spies, Ingrid B.M.; Willumsen, Niels J.

    1995-01-01

    Mitochondria-rich cells (MRC) of the amphibian epidermis are responsible for active chloride uptake at low external salinity, and new MRCs are recruited in response to exposure to distilled (deionized) water. The time-course of this recruitment, the tissue kinetics and ion transport have been...... decreased ICl and H+ flux per MRC, and by the increased proportion of MRCs unstained by Ag or MB. Full Cl- (but not H+) transport capacity, was restored at day-7. We conclude that increased DMRC following exposure to low external Cl-, rather than being due to an increased Kb, is the combined effect of a...

  20. The genetics of amphibian decline: population substructure and molecular differentiation in the Yosemite toad, Bufo canorus (Anura, Bufonidae) based on single-strand conformation polymorphism analysis (SSCP) and mitochondrial DNA sequence data

    Science.gov (United States)

    Shaffer, H.B.; Fellers, G.M.; Magee, A.; Voss, S.R.

    2000-01-01

    (1) DDT, dieldrin, and heptachlor were each applied to separate replicate plots in a hay field at 0.6, 2.2, or 9.0 kg/ha. For 11 yr thereafter, soil and earthworms were analysed for residues. (2) The average ratios of residues in earthworms (dry weight) to residues in soil (dry weight) were: total DDT, 5; dieldrin, 8; and heptachlor epoxide, 10. The average time for the initial residues in soil to be reduced by 50% were: total DDT, 3.2 yr; dieldrin, 5.1 yr; and heptachlor epoxide, 3.2 yr. The corresponding times for residues in earthworms were: total DDT, 3.2 yr; dieldrin, 2.6 yr; and heptachlor epoxide, 3.0 yr. (3) DDE was most persistent, and in plots treated at 9.0 kg/ha its concentration remained constant at about 0.4 ppm in soil and about 7 ppm in earthworms. (4) When applied at 9.0 kg/ha, DDT accumulated in earthworms to concentrations (32 ppm) which laboratory studies have shown to be hazardous to some sensitive bird species. When heptachlor was applied at 2.2 or 9.0 kg/ha, heptachlor epoxide in earthworms reached concentrations (8 ppm) potentially hazardous to woodcock. Dieldrin remained at potentially hazardous concentrations (8 ppm) for 3 yr in plots treated with 2.2 kg/ha and for 11 yr in plots treated with 9.0 kg/ha.

  1. Phylogenetic analysis of bluetongue virus serotype 4 field isolates from Argentina.

    Science.gov (United States)

    Legisa, D; Gonzalez, F; De Stefano, G; Pereda, A; Dus Santos, M J

    2013-03-01

    Bluetongue is an insect-transmitted viral disease of ruminant species, which represents a major barrier to the international trade of animals and their products. Bluetongue virus (BTV) has a genome composed of ten linear segments of dsRNA, which code for at least ten different viral proteins. In South America, serological evidence for the presence of BTV has been found in Peru, Argentina, Brazil, Ecuador and Chile. Brazil and Argentina are the only South American countries where BTV has been isolated. In Brazil, only one BTV isolate, serotype 12, has been reported, whereas in Argentina five BTV serotype 4 isolates have been obtained from cattle without clinical signs. Three of these five isolates were isolated during 1999-2001, whereas two of them were obtained as part of the present work. This study describes sequence comparisons and phylogenetic analyses of segment (Seg)-2, Seg-3, Seg-6, Seg-7 and Seg-10 of the first Argentinian field isolates of BTV. The analysis of Seg-2 and Seg-6 resulted in a single cluster of Argentinian sequences into the serotype 4 clade. In addition, the Argentinian sequences grouped within the nucleotype A clade, along with reference strains. The analysis of Seg-3, Seg-7 and Seg-10 showed that the Argentinian isolates grouped into the western topotype, indicating that the circulating virus had an African/European origin. Phylogenetic analysis revealed that the Argentinian sequences present a South American genetic identity, suggesting an independent lineage evolution. PMID:23152367

  2. The Role of Domain-Specific Practice, Handedness, and Starting Age in Chess

    Science.gov (United States)

    Gobet, Fernand; Campitelli, Guillermo

    2007-01-01

    The respective roles of the environment and innate talent have been a recurrent question for research into expertise. The authors investigated markers of talent, environment, and critical period for the acquisition of expert performance in chess. Argentinian chess players (N = 104), ranging from weak amateurs to grandmasters, completed a…

  3. Draft Genome Sequences of Burkholderia contaminans, a Burkholderia cepacia Complex Species That Is Increasingly Recovered from Cystic Fibrosis Patients

    OpenAIRE

    Bloodworth, Ruhi A M; Selin, Carrie; López De Volder, Maria Agustina; Drevinek, Pavel; Galanternik, Laura; Degrossi, José; Cardona, Silvia T.

    2015-01-01

    Burkholderia contaminans belongs to the Burkholderia cepacia complex (BCC), a group of bacteria that are ubiquitous in the environment and capable of infecting the immunocompromised and people with cystic fibrosis. We report here draft genome sequences for the B. contaminans type strain LMG 23361 and an Argentinian cystic fibrosis sputum isolate.

  4. Subduction controls on Miocene back-arc lavas from Sierra de Huantraico and La Matancilla, Argentina and new 40Ar/39Ar dating from the Mendoza Region, Argentina

    DEFF Research Database (Denmark)

    Dyhr, Charlotte Thorup; Holm, Paul Martin; Llambias, Eduardo J.; Scherstén, Anders

    2013-01-01

    Back-arc volcanism in the western Argentinian provinces of Mendoza and Neuquén has been widespread from the Miocene to historic times. We present a detailed investigation of profiles through two of the major Miocene volcanic areas of the region, the neighboring Huantraico and LaMatancilla plateau...

  5. University Statistics. Third Issue

    Directory of Open Access Journals (Sweden)

    Gabriela S. Giba

    2014-06-01

    Full Text Available Based on the CONEAU document "Accredited postgraduate courses in the Argentinian Republic-2013” the state of university graduate programs accredited under the provisions of Law No. 24,512 on Higher Education (SLE is analyzed, as compared in numb  ers to previous calls.

  6. In-service inspection of steam generator pipes

    International Nuclear Information System (INIS)

    Tasks achieved during in-service inspection by Eddy currents in steam generator pipes of Atucha Reactor are described. Argentinian technicians made an ''on-the-job training'' under the supervision of KWU's personnel. This inspection was realized between November and December 1987

  7. Estrategias reproductivas de moluscos bivalvos y equinoideos

    OpenAIRE

    Calvo, J.; Morriconi, E.; Orler, P.

    1998-01-01

    The theoretical aspects of reproductive strategies and life histories are analyzed. The gonadal structures and the main features of gametogenesis of bivalves and echinoids are described. Research on the reproductive characteristics and gametogenic cycles of the bivalve molluscs in the Argentinian littoral and the echinoid Loxechinus albus is reviewed. Special references to Mytilus edulis, Aulacomya ater, Brachidontes purpuratus, Aequipecten tehuelchus, Zygochlamys patagonica, Ostrea puelchana...

  8. Specifika podnikatelského prostředí Argentinské republiky

    OpenAIRE

    Nováková, Karolína

    2010-01-01

    Presented work analyzes the business environment of the Republic of Argentina. It focuses on the economic, political and legislative, cultural and social, and institutional environment. It evaluates the mutual commercial relations between the Czech and Argentinian Republic and suggests possible business opportunities for their commercial exchange.

  9. An Introduction to American Literature.

    Science.gov (United States)

    Borges, Jorge Luis

    Offered in this book is an Argentinian's view of the literary achievement of the United States. The beginning chapters discuss Mather, Edwards, and Freneau; Franklin, Cooper, and the historians; Hawthorne and Poe; and Whitman and Herman Melville. Other chapters are given to a discussion of three poets of the nineteenth century (Lanier, Whittier,…

  10. Rahvusvahelisel muuseumipäeval 18. V avati Tartu Kunstimuuseumis Raekoja plats 18... / Reeli Kõiv

    Index Scriptorium Estoniae

    Kõiv, Reeli

    2005-01-01

    Näituse kuraator ülevaatenäitusest "Tartu kunsti lood", mis esitab Tartu kunsti arenguloo rohkem kui pooleteise sajandi lõikes. Näitusega kaasnevad muuseumitunnid ja töötoad igas vanuses lastele ja noortele

  11. SURROGATE SPECIES IN ASSESSING CONTAMINANT RISK FOR ENDANGERED FISHES

    Science.gov (United States)

    Rainbow trout, fathead minnows, and sheepshead minnows were tested as surrogate species to assess contaminant risk for 17 endangered fishes and one toad species. Acute toxicity tests were conducted with carbaryl, copper, 4-nonylphenol, pentachlorophenol, and permethrin in accord...

  12. SURROGATE SPECIES IN ASSESSING CONTAMINANT RISK FOR ENDANGERED FISHES, INCLUDING INTERSPECIES TOXICITY CORRELATIONS

    Science.gov (United States)

    Rainbow trout, fathead minnows, and sheepshead minnows were tested as surrogate species to assess contaminant risk for 17 endangered fishes and one toad species. Acute toxicity tests were conducted with carbaryl, copper, 4-nonylphenol, pentachlorophenol, and permethrin in accorda...

  13. Instruction Manual and Frog Survey Protocols for Region 1 National Wildlife Refuges, East-side Zone

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This manual is intended to assist biologists wishing to conduct surveys for frogs and toads. The document includes detailed information on how to conduct surveys,...

  14. Detection of the emerging amphibian pathogens Batrachochytrium dendrobatidis and ranavirus in Russia

    Science.gov (United States)

    Reshetnikov, Andrey N.; Chestnut, Tara E.; Brunner, Jesse L.; Charles, Kaylene M.; Nebergall, Emily E.; Olson, Deanna H.

    2014-01-01

    In a population of the European common toad Bufo bufo from a rural pond in the region of Lake Glubokoe Regional Reserve in Moscow province, Russia, unexplained mass mortality events involving larvae and metamorphs have been observed over a monitoring period of >20 yr. We tested toads from this and a nearby site for the emerging amphibian pathogens Batrachochytrium dendrobatidis (Bd) and ranavirus (Rv). Both pathogens were detected, and at the rural pond site, with the above-noted losses and decline in toad breeding success, 40% of B. bufo metamorphs were Bd positive, 46% were Rv positive and 20% were co-infected with both pathogens. Toad metamorphs from a neighbouring water body were also Bd and Rv positive (25 and 55%, respectively). This is the first confirmation of these pathogens in Russia. Questions remain as to the origins of these pathogens in Russia and their roles in documented mass mortality events.

  15. 77 FR 2993 - Final Environmental Impact Statement and Record of Decision on Oncor Electric Delivery Company's...

    Science.gov (United States)

    2012-01-20

    ... the HCP and to evaluate alternatives, along with the draft HCP (76 FR 41808). We included public... ladies'-tresses (Spiranthes parksii) American burying beetle (Nicrophorus americanus) Houston toad...

  16. Surgical Webcast for Treatment of Acid Reflux

    Medline Plus

    Full Text Available ... number one, so that they don’t have bloating. And there are certainly things that increase that ... the stomach and will kind of make them bloat like a toad, and they’ll be quite ...

  17. Amphibian abnormalities on National Wildlife Refuges

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This fact sheet outlines a study done to 1 find the percentage of abnormal frogs and toads on the nations National Wildlife Refuges and 2 determine how the...

  18. CRED Optical Validation Data collected on Maui, Main Hawaiian Islands, USA, in 2015 to support Benthic Habitat Mapping

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Optical validation data were collected using a Tethered Optical Assessment Device (TOAD), an underwater sled equipped with an underwater digital video camera,...

  19. Valge fungi uus tulemine / Kersti Pikk

    Index Scriptorium Estoniae

    Pikk, Kersti

    2007-01-01

    Peeter Tambu projekteeritud valge "eestiaegne" funk eramu, kus avatud planeeringu asemel on paraja suurusega eraldi toad, esikohal ruumide otstarbekus ja ratsionaalsus. Arhitekt on kujundanud interjööri ja mööbli

  20. Effects of an insecticide on amphibians in large-scale experimental ponds

    Science.gov (United States)

    Boone, M.D.; Semlitsch, R.D.; Fairchild, J.F.; Rothermel, B.B.

    2004-01-01

    We examined the effects of the insecticide carbaryl on larval amphibian communities in large-scale experimental ponds. Tadpoles of two anurans, Woodhouse's toad (Bufo woodhousii) and southern leopard Frog (Rana sphenocephala), were reared in ponds (800 m3 volume) to determine the effects of tadpole density and carbaryl exposure on mass at metamorphosis and on time and survival to metamorphosis. Exposure to carbaryl significantly affected toads at metamorphosis, but not leopard frogs. Carbaryl exposure nearly doubled toad survival compared to controls; this effect may be attributable to an indirect effect of earbaryl increasing algal food resources. The competitive environment (i.e., density) and carbaryl exposure significantly affected the trade-off between mass and time to metamorphosis for toads. Our study is the first to demonstrate that in pond communities where predation and competition may be strong, short-lived insecticides can significantly alter the community dynamics of amphibians.

  1. Filmifestival õpetas ise filme looma / Aarne Mäe

    Index Scriptorium Estoniae

    Mäe, Aarne, 1967-

    1999-01-01

    30. sept. - 3. okt. Rakvere Exclusiveì ööklubis toimunud Põhjamaade ja Baltikumi noorte videofilmide filmifestivali "Visions of Light" raames tegutsesid ka töötoad : Eesti nukufilmi töötuba ja "Video netis"

  2. Surviving Chytridiomycosis: Differential Anti-Batrachochytrium dendrobatidis Activity in Bacterial Isolates from Three Lowland Species of Atelopus

    OpenAIRE

    Flechas, Sandra V.; Sarmiento, Carolina; Martha E Cárdenas; Edgar M Medina; Restrepo, Silvia; Amézquita, Adolfo

    2012-01-01

    In the Neotropics, almost every species of the stream-dwelling harlequin toads (genus Atelopus) have experienced catastrophic declines. The persistence of lowland species of Atelopus could be explained by the lower growth rate of Batrachochytrium dendrobatidis (Bd) at temperatures above 25°C. We tested the complementary hypothesis that the toads' skin bacterial microbiota acts as a protective barrier against the pathogen, perhaps delaying or impeding the symptomatic phase of chytridiomycosis....

  3. The herpetofauna of Timor-Leste: a first report

    OpenAIRE

    Hinrich Kaiser; Venancio Lopes Carvalho; Jester Ceballos; Paul Freed; Scott Heacox; Barbara Lester; Richards, Stephen J.; Trainor, Colin R.; Caitlin Sanchez; Mark O’Shea

    2011-01-01

    Abstract Fieldwork conducted throughout Timor-Leste in September 2004 and July 2009 resulted in a collection or recording of 263 herpetological specimens (100 amphibians, 163 reptiles), comprising at least seven species of frogs and toads, 20 species of lizards, seven species of snakes, two species of turtles, and one species of crocodile. Among the amphibians, the most frequently encountered species were toads ( Duttaphrynus melanostictus ), rice paddy frogs (genus Fejervarya ), and rhacopho...

  4. Trophic ecology and microhabitat utilization by the Bufo gargarizans, Rana guentheri, and Rana limnocharis in southwestern China

    OpenAIRE

    Tonglei Yu; Yanshu Guo

    2012-01-01

    We studied the trophic ecology and microhabitat use of the Asiatic toad, Bufo gargarizans Cantor, 1842; Guentheri frog, Rana guentheri (Boulenger, 1882); and the Ricefield frog, Rana limnocharis (Boie, 1834). These three species are common around Nanchong City, in southwestern China, where they live in the same habitat before hibernation. The main objective of this study was to analyze the diets and patterns of coexistence relative to the microhabitat of each species. In the Asiatic toad, bas...

  5. Dynamic characterization of silicon nanowires using a terahertz optical asymmetric demultiplexer-based pump-probe scheme

    DEFF Research Database (Denmark)

    Ji, Hua; Cleary, C. S.; Dailey, J. M.;

    2012-01-01

    Dynamic phase and amplitude all-optical responses of silicon nanowires are characterized using a terahertz optical asymmetric demultiplexer (TOAD) based pump-probe scheme. Ultra-fast recovery is observed for moderate pump powers.......Dynamic phase and amplitude all-optical responses of silicon nanowires are characterized using a terahertz optical asymmetric demultiplexer (TOAD) based pump-probe scheme. Ultra-fast recovery is observed for moderate pump powers....

  6. Use of stress-hormone levels and habitat selection to assess functional connectivity of a landscape for an amphibian.

    Science.gov (United States)

    Janin, Agnès; Léna, Jean-Paul; Deblois, Sandrine; Joly, Pierre

    2012-10-01

    The influence of landscape matrix on functional connectivity has been clearly established. Now methods to assess the effects of different land uses on species' movements are needed because current methods are often biased. The use of physiological parameters as indicators of the level of resistance to animal movement associated with different land uses (i.e., matrix resistance) could provide estimates of energetic costs and risks to animals migrating through the matrix. To assess whether corticosterone levels indicate matrix resistance, we conducted experiments on substrate choice and measured levels of corticosterone before and after exposure of toads (Bufo bufo) to 3 common substrates (ploughed soil, meadow, and forest litter). We expected matrix resistance and hormone levels to increase from forest litter (habitat of the toad) to meadows to ploughed soil. Adult toads had higher corticosterone levels on ploughed soil than on forest litter or meadow substrates. Hormone levels did not differ between forest litter and meadow. Toads avoided moving onto ploughed soil. Corticosterone levels in juvenile toads were not related to substrate type; however, hormone levels decreased as humidity increased. Juveniles, unlike adults, did not avoid moving over ploughed soil. The difference in responses between adult and juvenile toads may have been due to differences in experimental design (for juveniles, entire body used to measure corticosterone concentration; for adults, saliva alone); differences in the scale of sensory perception of the substrate (juveniles are much smaller than adults); or differences in cognitive processes between adult and juvenile toads. Adults probably had experience with different substrate types, whereas juveniles first emerging from the water probably did not. As a consequence, arable lands could act as ecological traps for juvenile toads. PMID:22891816

  7. Can protected mountain areas serve as refuges for declining amphibians? Potential threats of climate change and amphibian chytridiomycosis in an alpine amphibian population. eco.mont (Journal on Protected Mountain Areas Research)|eco.mont Vol. 1 No. 2|

    OpenAIRE

    Sztatecsny, Marc; Hödl, Walter

    2009-01-01

    In June 2004 and June 2005, we checked 40 and 134 ponds respectively for alive and dead alpine newts, common toads, common frogs, and their clutches on the "Kirchfeld" plateau in the Northern Limestone Alps of Austria. We found several hundred dead common frogs and alpine newts in the two consecutive years and also observed an unusually high number of heterospecific matings between common toads and common frogs in 2004. In order to test whether the observed mortalities were caused by disease,...

  8. Relationship between the genetic structure of the Andean toad Rhinella spinulosa (Anura: Bufonidae and the northern Chile landscape (21°- 24° S Relación entre la estructura genética del sapo andino Rhinella spinulosa (Anura: Bufonidae y el paisaje del norte de Chile (21°- 24° S

    Directory of Open Access Journals (Sweden)

    CAROLINA E GALLARDO

    2011-09-01

    Full Text Available We analyzed the relationship of landscape and environmental features on the genetic differentiation of Rhinella spinulosa (Wiegmann, 1834 in the Altiplano of Antofagasta (Chile. We performed three types of analyses at different spatial scales: (1 Considering all populations; (2 Grouping populations by watershed and by sub-watershed; and (3 Using the results of a spatial analysis of molecular variation (SAMOVA. Landscape features were incorporated using Geographic Information Systems, with three hypothetical dispersal models: (1 Euclidean distance (null model; (2 Least cost based on wetland locations; and (3 Least cost based on least slopes. We also included differences in temperature, precipitation and altitude among localities. The Akaike information criterion was used to select the best model and the relative importance of each variable in the model was estimated with partial regressions. We found a high genetic differentiation among populations (Fst = 0.693 and isolation by distance (r = 0.767. AMOVA showed that the watersheds explained 8.67 % of the genetic variance and sub-watersheds 35.99 %. At the largest spatial scale, considering all populations, the model that best explained genetic differentiation included Euclidean distance, altitude and annual precipitation. At a smaller scale, in two of three sub-watersheds (Río San Pedro and Salar de Atacama the genetic differentiation was best explained by landscape variables (principally temperature and altitude. At the smallest scale, considering those populations that have diverged recently detected by SAMOVA, the genetic differentiation was best explained by the wetland-based route and annual precipitation. This approach revealed the importance of landscape features in the colonization of R. spinulosa in this zone.Se evaluó la relación entre las características del paisaje y ambientales y la diferenciación genética de Rhinella spinulosa en el altiplano de la Región de Antofagasta (Chile. Para esto se realizaron tres tipos de análisis a diferentes escalas espaciales: (1 considerando todas las poblaciones; (2 agrupando las poblaciones por cuencas y por subcuencas; y (3 utilizando los resultados del análisis espacial de variación molecular (SAMOVA. Las características del paisaje se incorporaron diseñando tres modelos hipotéticos de dispersión con los Sistemas de Información Geográfico: (1 distancia euclidiana (modelo nulo; (2 de menor costo basado en la localización de los humedales; y (3 de menor costo basado en las pendientes menores. Además, se incluyeron las diferencias en temperatura, precipitación y altitud entre localidades. Para seleccionar el modelo que mejor explicara la diferenciación genética se utilizó el Criterio de Información de Akaike y se estimó la importancia relativa de cada variable del modelo seleccionado utilizando regresiones parciales. Se encontró una alta diferenciación genética entre las poblaciones (Fst = 0.693 y un patrón claro de aislamiento por distancia (r = 0.767. El análisis AMOVA mostró que las cuencas explicaron un 8.67 % de la varianza genética y las subcuencas un 35.99 %. A mayor escala espacial, considerando todas las poblaciones, el mejor modelo que explicó la diferenciación genética incluyó las variables distancia euclidiana, altitud y precipitación anual. A menor escala, en dos de las tres subcuencas (Río San Pedro y Salar de Atacama la diferenciación genética fue mejor explicada por variables del paisaje (temperatura y altitud, principalmente. A menor escala, considerando las poblaciones que han divergido recientemente detectadas por SAMOVA, la diferenciación genética fue mejor explicada por la ruta basada en humedales y la precipitación anual. Esta aproximación muestra la importancia de las características del paisaje en la colonización de R. spinulosa en esta zona.

  9. Relationship between the genetic structure of the Andean toad Rhinella spinulosa (Anura: Bufonidae) and the northern Chile landscape (21°- 24° S) Relación entre la estructura genética del sapo andino Rhinella spinulosa (Anura: Bufonidae) y el paisaje del norte de Chile (21°- 24° S)

    OpenAIRE

    CAROLINA E GALLARDO; HÉCTOR J HERNÁNDEZ; Diniz-Filho, José A. F.; R. EDUARDO PALMA; MARCO A MÉNDEZ

    2011-01-01

    We analyzed the relationship of landscape and environmental features on the genetic differentiation of Rhinella spinulosa (Wiegmann, 1834) in the Altiplano of Antofagasta (Chile). We performed three types of analyses at different spatial scales: (1) Considering all populations; (2) Grouping populations by watershed and by sub-watershed; and (3) Using the results of a spatial analysis of molecular variation (SAMOVA). Landscape features were incorporated using Geographic Information Systems, wi...

  10. The Test Observation of Electrical Physiology about the Exhausted Recovery of a Toad's Calf Intestines Muscle Specimen by Acupuncture%关于针刺对蟾蜍腓肠肌标本疲劳恢复的电生理实验观察

    Institute of Scientific and Technical Information of China (English)

    黄琰

    2002-01-01

    以蟾蜍为实验对象,对蟾蜍腓肠肌标本进行电刺激收缩达到一定的疲劳程度后,分别采取休息和针刺方法恢复,观察整个过程中的肌肉收缩曲线并分析.实验结果显示:针刺可以大幅度地提高肌肉在疲劳后恢复中的最大用力.

  11. Representaciones Sociales de la Historia Universal: Posicionamientos Diferenciales en Función de la Ideología Política, Religiosidad y Nacionalismo en una Muestra Argentina/RepresentationsSocial Representations of Universal History: Differential Positioning at the Service of Political Ideology, Religiosity and Nationalism in the Argentinian Context/Representações Sociais da História Universal: Posicionamentos Diferenciados em função da Ideologia Política, da Religiosidade e do Nacionalismo numa Amostra Argentina

    OpenAIRE

    Fernanda Mariel Sosa; Gisela Isabel Delfino; Magdalena Bobowik; Elena Mercedes Zubieta

    2016-01-01

    Con el objetivo de analizar las representaciones sociales de la historia a través de los sentimientos que despiertan 24 personajes de la historia universal, se administró una versión modificada del cuestionario construido por Liu et al. (2005) a una muestra intencional (n=369) de Argentina (55.7% mujeres, medad=36.20, deedad=11.16). El análisis de conglomerados no jerárquico arrojó 4 grupos en función de la religiosidad, el nacionalismo y el posicionamiento ideológico de los participantes. Po...

  12. Representaciones Sociales de la Historia Universal: Posicionamientos Diferenciales en Función de la Ideología Política, Religiosidad y Nacionalismo en una Muestra Argentina/RepresentationsSocial Representations of Universal History: Differential Positioning at the Service of Political Ideology, Religiosity and Nationalism in the Argentinian Context/Representações Sociais da História Universal: Posicionamentos Diferenciados em função da Ideologia Política, da Religiosidade e do Nacionalismo numa Amostra Argentina

    Directory of Open Access Journals (Sweden)

    Fernanda Mariel Sosa

    2016-03-01

    Full Text Available Con el objetivo de analizar las representaciones sociales de la historia a través de los sentimientos que despiertan 24 personajes de la historia universal, se administró una versión modificada del cuestionario construido por Liu et al. (2005 a una muestra intencional (n=369 de Argentina (55.7% mujeres, medad=36.20, deedad=11.16. El análisis de conglomerados no jerárquico arrojó 4 grupos en función de la religiosidad, el nacionalismo y el posicionamiento ideológico de los participantes. Por su parte, del análisis de clúster jerárquico, en función de los sentimientos hacia los personajes, se desprendieron 2 conglomerados denominados héroes y villanos. Los personajes religiosos y políticos son los que mayor disenso suscitan.

  13. Microbiome Variation Across Amphibian Skin Regions: Implications for Chytridiomycosis Mitigation Efforts.

    Science.gov (United States)

    Bataille, Arnaud; Lee-Cruz, Larisa; Tripathi, Binu; Kim, Hyoki; Waldman, Bruce

    2016-01-01

    Cutaneous bacteria may play an important role in the resistance of amphibians to the pathogenic fungus Batrachochytrium dendrobatidis (Bd). Microbial communities resident on hosts' skin show topographical diversity mapping to skin features, as demonstrated by studies of the human microbiome. We examined skin microbiomes of wild and captive fire-bellied toads (Bombina orientalis) for differences across their body surface. We found that bacterial communities differed between ventral and dorsal skin. Wild toads showed slightly higher bacterial richness and diversity in the dorsal compared to the ventral region. On the other hand, captive toads hosted a higher richness and diversity of bacteria on their ventral than their dorsal skin. Microbial community composition and relative abundance of major bacterial taxonomic groups also differed between ventral and dorsal skin in all populations. Furthermore, microbiome diversity patterns varied as a function of their Bd infection status in wild toads. Bacterial richness and diversity was greater, and microbial community structure more complex, in wild than captive toads. The results suggest that bacterial community structure is influenced by microhabitats associated with skin regions. These local communities may be differentially modified when interacting with environmental bacteria and Bd. A better understanding of microbiome variation across skin regions will be needed to assess how the skin microbiota affects the abilities of amphibian hosts to resist Bd infection, especially in captive breeding programs. PMID:26271741

  14. Absence of tetrodotoxins in a captive-raised riparian frog, Atelopus varius.

    Science.gov (United States)

    Daly, J W; Padgett, W L; Saunders, R L; Cover, J F

    1997-05-01

    Bufonid frogs of the genus Atelopus contain two classes of skin toxins, namely the steroidal bufadienolides and the water-soluble tetrodotoxins. Frogs of the Panamanian species Atelopus varius have now been raised in captivity and levels in skin extracts of bufadienolides and of tetrodotoxin-like compounds assessed, using inhibition of [3H]ouabain binding and inhibition of [3H]saxitoxin binding, respectively. Levels of ouabain equivalents, corresponding to bufadienolides, were comparable to those found in wild-caught frogs from the same population in Panama, while tetrodotoxin-like activity was undetectable. The results strongly implicate environmental factors, perhaps symbiotic microorganisms, in the genesis of tetrodotoxins in the skin of frogs of the genus Atelopus, while indicating that the frog itself produces the skin bufadienolides. PMID:9203295

  15. Revisiting Germani: the interpretation of modernity and the theory of action

    OpenAIRE

    José Maurício Domingues; María Maneiro; Deborah Neale

    2005-01-01

    The work of the Italo-Argentinian sociologist Gino Germani has traditionally been classified as functionalist. However, recent studies have tended to change this perspective, emphasizing other important influences in his work. Against the backdrop of his broader theory, the objective of this article is to analyze, on the one hand, his perception, in the Latin American transition to modernity, of freedom as the essential issue in politics and daily life, and on the other, how this translates i...

  16. Migration and exile: memories of recent Argentine history through film

    Directory of Open Access Journals (Sweden)

    Osvaldo Esteban, Fernando

    2008-11-01

    Full Text Available This article uses a selection of films to explore the causes that prompted the international migration of Argentinians, for political and economic reasons, using an insider's point of view. I examine the theme of identity, that is, the relationship of individuals with their place of origin, their environment and their country. Also, the aim of this paper is to discuss the validity of film as valuable material in the analysis of the subtleties of social meanings.

  17. The Right to Safe Drinking Water as a Human Right

    OpenAIRE

    Picolotti, Romina

    2013-01-01

    This text has been published in the Housing and ESC Rights Law Quarterly, Vol. 2, n° 1 (Geneva: Centre on Housing Rights & Evictions, 2005) Introduction During a research programme studying the dimensions of poverty, human rights and environment, an Argentinian NGO, CEDHA, identified the lack of access to safe drinking water in outlying poor neighbourhoods as a critical problem in the city of Córdoba, Argentina. This two-year research programme focused on specific geographical areas around Có...

  18. El silencio de las imágenes. Las ilustraciones a Una excursión a los indios ranqueles

    OpenAIRE

    Amanda Salvioni

    2015-01-01

    A Travel to the Ranquel Indians, by L.V. Mansilla, has been defined as the only text of Nineteenth Century Argentinian literature where the voices of natives clearly emerged. Nevertheless, in the history of its reception these voices were silenced by white society and the book was reduced to its anecdotal dimension. Paradoxically, the more the natives became mute, the more they were visible, converted into images, icons and mere representations. At the same time, more and more illustrations w...

  19. Obesity Epidemic in Brazil and Argentina: A Public Health Concern

    OpenAIRE

    Arbex, Alberto K; Rocha, Denise R.T.W.; Aizenberg, Marisa; Ciruzzi, Maria S.

    2014-01-01

    ABSTRACT The obesity epidemic is rapidly advancing in South America, leading to inevitable health consequences. Argentinian and Brazilian health policies try to become adapted to the new economic and social framework that follows from this epidemic. It is in incipient and ineffective control so far since the prevalence of obesity was not restrained. The Argentine national legislation is more advanced, through the so-called “Ley de Obesidad.” In Brazil, there are numerous local initiatives but...

  20. Demandas de turismo Argentina y Brasileña en Uruguay

    OpenAIRE

    Silvia Altmark; Gabriela Mordecki; Florencia Santiñaque; W. Adrián Risso

    2012-01-01

    Argentinian and Brazilian demands for tourism in Uruguay are analyzed separately. These countries represent 66.25% of the receptive tourism in Uruguay, however they presente different characteristics. Two long-run relationships among tourism expenditures, income and real touristic exchange rate are found by applying the cointegrating methodology. The income-demand elasticity is positive and larger than one in both cases, confirming the hypothesis that tourism is a luxury good. Moreover, this ...

  1. El liberalismo conservador y la ideología del Proceso de Reorganización Nacional

    Directory of Open Access Journals (Sweden)

    Sergio Morresi

    2010-06-01

    Full Text Available This article aims to show that the political ideas of the selfnamed "National Reorganization Process -Proceso de Reorganización Nacional [PRN]" -were structured within the ideological frame offered by conservative-liberalism. Through the study of some of the ideologicalpromoters of the PRN, it is argued that conservative-liberalism served as merger of the different types of argentinian rights and laid the foundations for the neoliberal ideas that were impelled afer the dictatorship period

  2. Erythromycin-Resistant Streptococcus pyogenes in Argentina Resistencia a la eritromicina en Streptococcus pyogenes en la Argentina

    OpenAIRE

    Lopardo, Horacio A.; Claudia Hernandez; Patricia Vidal; Miryam Vazquez; Liliana Rosaenz; Gabriela Rubinstein; Jorgelina Smayevsky; Marta Tokumoto; Adriana Fernandez Lausi; Omar Daher; Sara Kaufman; Silvia V. Soriano; Susana Brasili; Marina Bottiglieri; Maria Cristina Carranza

    2004-01-01

    Erythromycin (ERY) resistance in Streptococcus pyogenes has recently emerged as a problem of growing concern all through the world. We are presenting the comparison of results of the continuous surveillance of erythromycin resistance in S. pyogenes performed since 1989 in the Hospital de Pediatría J.P.Garrahan of Buenos Aires City, with independently observed rates in other five centers of Buenos Aires and seven centers of six other Argentinian cities, obtained between 1999 and 2001. A signif...

  3. Las armas de la conquista. Presencia de armas de fuego en sitios coloniales de Argentina

    OpenAIRE

    Ana Igareta; Vanina Castillón

    2013-01-01

    Objects used as weapons by the man had interested archaeologists worldwide since the early times of the discipline. Cultural sequences had been defined using the evolution arms as one of the relevant material indicators of social development. Argentinian archaeology has an extensive tradition of prehistoric weapons studies, but little attention has been accorded to the repertoire of arms -particulary firearmsused during colonial confrontations between Spanish soldiers and nativ...

  4. An Iron Law of Currency Crises: The Divergence of the Nominal and the Real Exchange Rate and Increasing Current Account Deficits

    OpenAIRE

    Siebert, Horst

    2002-01-01

    The currency crises of the 1990s all exhibit a divergence of the nominal and the real exchange rate together with an increase in the negative current account. The nominal rate does not reflect inflation differences fully and the ensuing real appreciation leads to a negative current account. This pattern holds for the Czech, the Mexican, Brazilian, Argentinian as well as the South Korean currency crises. It seems to be an iron law of currency crises.

  5. Estudio de los procesos biotecnológicos de acetificación para la producción de vinagre de naranja y vinagre de arándanos.

    OpenAIRE

    DAVIES, CRISTINA VERÓNICA

    2016-01-01

    [EN] The province of Entre Ríos, in Argentina, has been characterized by citrus production for decades and more recently, by blueberry production. A high percentage (15-25 %) of Argentinian orange production has been derived to industry due to the difficulty to commercialize in more profitable trades, in the last five years. In addition, the increasing volume of blueberries not suitable to export, with limited presence in the domestic market and few industrialization possibilities, has caused...

  6. Rappresentazioni e (in)traducibilità del delirio: Informe sobre ciegos di Alberto Breccia

    OpenAIRE

    Susanna Nanni

    2015-01-01

    The essay proposes an analysis of the relationship between text and images in Informe sobre ciegos (1991) by Alberto Breccia. In his obstinate renunciation to unnecessary words, or surplus signs, and by employing graphic devices that convey a "telluric and formless" world, Breccia interprets and illustrates – without making it comprehensible – the self-destructive delirious state of Fernando Vidal, one of the most controversial and fascinating characters in Argentinian literature. In particul...

  7. Antarctic network of lamp-calibrated multichannel radiometers for continuous ozone and uv radiation data

    OpenAIRE

    Redondas, A.; Torres, C.; O. Meinander; K. Lakkala; R. García; E. Cuevas; Ochoa, H.; Deferrari, G.; Díaz, S.

    2008-01-01

    Three NILU-UV multichannel radiometers have been installed in 1999 at the Argentinian sites of Ushuaia (54S), Marambio (64S) and Belgrano-II (77S) in order to continuously monitor UV radiation, photosynthetically active radiation and total ozone. The measurements were established by INM, Spain in collaboration with FMI, Finland, DNA-IAA, Argentina and CADIC, Argentina to observe and characterize the spatial and temporal evolution of ozone and ultraviolet radiation in the Antarctic region. Spe...

  8. Wladimiro Acosta y la vivienda colectiva (1928 - 1935) : su aporte a la innovación arqueológica y tipológica en América Latina

    OpenAIRE

    Ranzini, Marcelo

    2015-01-01

    VVladimiro Acosta (WA) was a Russian architect with centro-european modem studies. His moving to Latin America in 1928 he meant one of the most significant contributions to Argentinian architecture. Since his arrival until 1935 he would develop ten social housing prototypes, which although they were never built they still represent one of the main and most complete studies on housing unit. The hypothesis which leads this thesis shows these prototypes as one of the most significant contributio...

  9. The genus Bostryx in central western Argentina: anatomical and distributional description of four of its southernmost species (Gastropoda, Bulimulidae)

    OpenAIRE

    María José Miranda

    2015-01-01

    ABSTRACT The genus Bostryx Troschel, 1847 is endemic to South America, extending from Ecuador to Chile and Argentina. The southernmost Argentinian species of the genus that inhabit San Luis, San Juan and Mendoza provinces, specially the pre-Andes, Andes and Sierras Pampeanas mountain ranges, were examined. This is the first time the anatomy of Bostryx pastorei (Holmberg, 1912), Bostryx reedi (Parodiz, 1947) and Bostryx strobeli (Parodiz, 1956) has been described.Bostryx cordillerae (Strobel, ...

  10. Salones y marchantes de arte en la Argentina (1890-1925

    Directory of Open Access Journals (Sweden)

    Gutiérrez Viñuelas, Rodrigo

    1999-06-01

    Full Text Available The present work points his attention in the exhibition's rooms in Argentina at the end of the 19th century and the beginnings of the 20th, its characteristics and main activities, and the art merchants labor during the same period. It is a contribution about some aspects of the argentinian art market, that pretends to bring new facts and contributes to think about an open debate on a research topic to be deepen.No disponible

  11. ZinjaI: an integrated development environment for a first programming course with C++

    OpenAIRE

    Novara, Pablo; Loyarte, Horacio

    2009-01-01

    Most of the students in Argentinian universities tends to experience huge adaptation problem over their first year. It is the main cause for very high indexes of abandonment. In the case of computing/informatics systems careers, in the first programming course, the students must learn a series of concepts related to computing algorithms abstraction, programming language syntax and the real implementation of programs using C++. It is a known fact that this is a cryptic language for the beginne...

  12. Azar y psicoanálisis: Una interpretación del sueño en nadie nada nunca de Juan José Saer

    OpenAIRE

    Degrande, François

    2014-01-01

    . Our reading attempts to shed light on the literary project of the Argentinian writer as he plots the improbable relation of chance and psychoanalysis in his fifth novel, Nadie nada nunca. In this vein, the problematic coexistence of causality and chance can only be explained by the dictatorial terror that permeates this novel. To prove this, the article analyzes the oneiric world of El Gato (II), in which the freudian principle of condensation turns a bawdy house into a casino. This crucial...

  13. Future healthcare professionals’ knowledge about the Argentinean abortion law

    OpenAIRE

    Provenzano-Castro, Belén; Oizerovich, Silvia; Stray-Pedersen, Babill

    2016-01-01

    Objectives We assessed healthcare students’ knowledge and opinions on Argentinian abortion law and identified differences between first- and final-year healthcare students. Methods In this cross-sectional study, self-administered anonymous questionnaires were administered to 760 first- and 695 final-year students from different fields of study (medicine, midwifery, nursing, radiology, nutrition, speech therapy, and physiotherapy) of the School of Medicine at the University of Buenos Aires, in...

  14. First complete sequence of a giant linear plasmid from a micrococcus strain isolated from an extremely high-altitude lake.

    Science.gov (United States)

    Dib, Julián Rafael; Schuldes, Jörg; Thürmer, Andrea; Farias, María E; Daniel, Rolf; Meinhardt, Friedhelm

    2013-01-01

    Micrococcus sp. strain V7, an actinobacterial strain adapted to the extreme conditions of the Laguna Vilama, an extremely high-altitude (4,600 m above sea level) lake in the Argentinian Puna, was found to carry the giant linear plasmid pLMV7. We determined its sequence (92,815 bp) as a prerequisite to the investigation of its role in survival in such a harsh environment. PMID:24285659

  15. First Complete Sequence of a Giant Linear Plasmid from a Micrococcus Strain Isolated from an Extremely High-Altitude Lake

    OpenAIRE

    Schuldes, Jörg; Daniel, Rolf

    2013-01-01

    Micrococcus sp. strain V7, an actinobacterial strain adapted to the extreme conditions of the Laguna Vilama, an extremely high-altitude (4,600 m above sea level) lake in the Argentinian Puna, was found to carry the giant linear plasmid pLMV7. We determined its sequence (92,815 bp) as a prerequisite to the investigation of its role in survival in such a harsh environment.

  16. Vliv politicko-ekonomické situace v Argentině na spor o Malvíny/Falklandské ostrovy

    OpenAIRE

    Houšková, Lenka

    2014-01-01

    This bachelor thesis is dedicated to the Falkland Islands dispute between Argentina and the United Kingdom. It investigates Argentina's stand on the issue and its solution, while focusing on domestic political and economic conditions, and their influence on the dispute. Argentina's steps to reaching a solution and developments in Argentinian political system and economy are summarised. Consequently, it is discussed how and to which degree domestic conditions in Argentina have influenced the i...

  17. A través de la yerba mate: etnicidad y racionalidad económica entre los trabajadores rurales paraguayos en la industria de la construcción de Buenos Aires

    Directory of Open Access Journals (Sweden)

    Álvaro del Águila

    2014-04-01

    Full Text Available This article analyzes the process by which rural workers migrate from Paraguay to work in the Argentinian construction industry. There is some evidence that the migration process changes not only the lives of migrants but, in a profound way, their economic rationality. Employing an ethnographic perspective we contrast the work experiences of Paraguayan migrants at origin and at their point of arrival. The article casts light on the profound overlap between ethnicity, work and economic rationality.

  18. Sociologia, peronismo e esquerda na Argentina Sociology, peronism and left in Argentina

    OpenAIRE

    Carlos R. Etulain

    2007-01-01

    O trabalho discute, o papel do peronismo e os problemas político-ideológicos que ele coloca para a esquerda Argentina. Busca, também, apresentar os principais elementos para uma análise da esquerda frente ao fenômeno do peronismo. Palavras-chave: Peronismo. Esquerda. Trabalhadores. Movimentos sociais. Classes sociais. Capitalismo. Política. This paper presents the role of Peronism and the ideological political problems to be confronted by the Argentinian leftists...

  19. Los caracteres morfológicos del controvertido Neobatrachia arborícola Allophryne ruthveni Gaige, 1926

    Directory of Open Access Journals (Sweden)

    Fabrezi, Marissa

    2000-07-01

    Full Text Available Allophtyne ruthveni es un anuro neotropical arborícola asignado a una familia monotípica. Aunque sus afinidades con otros taxa permanecen sin precisar, durante mucho tiempo se lo relacionó con los anuros arborícolas neotropicales, aún cuando la ausencia de dientes, característica de los Bufonidae, fue el primer argumento para establecer alguna relación con estos. En el presente trabajo, presentamos un re-análisis de caracteres esqueléticos y miológicos de A. ruthveni a partir del cual encontramos ausencia de elementos intercalares, típicos de formas arborícolas; algunos rasgos compartidos con los bufónidos; y numerosos caracteres presentes en distintos neobatracios que deberían ser discutidos sobre la base de un análisis filogenético. Finalmente, consideramos dos características distintivas de las extremidades de A. ruthveni. Allophryne ruthveni is a neotropical arboreous frog assigned to a monotypical family. Although A. ruthveni's relationships remain poorly known, most of authors searched relationships with neotropical treefrogs in spite of the absence of teeth was an early evidence to relate it with bufonids. Herein, we presented a new analysis of osteological and some myological traits of A. ruthveni. Intercallary elements, related to the arboreal life style similar lo that present in neotropical treefrogs such as hylids, is very different in A. ruthveni; some cranial features of A. ruthveni represent traits shared with bufonids, and many morphological characters also are present among neobatracians. However, they can not be interpreted without a phylogenetic analysis. Finally, we considered two specific limb features of A. ruthveni.

  20. Italianos en la Argentina. Los últimos doscientos años / Italians in Argentina : the last two hundred years

    Directory of Open Access Journals (Sweden)

    Di Tella, Torcuato

    2011-06-01

    Full Text Available The 200 year anniversary of the foundation of Argentina and the 150th anniversary of Italian unification marks the occasion for an historical analysis of the presence of Italians in Argentina. The article examines the topic from the 1930s until post WW2, comparing immigration in Argentina with other nations including Australia and the US. The position of immigrants in Argentinian social structure is analysed, individualising 3 elements: that foreigners made up 30% of the population; that there was a high concentration of immigrants living in urban areas, and that in big cities foreigners made up 2/3 of the middle and working classes. Secondly, the influence of Italian immigrants on Argentinian politics is examined, in particular the influence on the Partido Socialista and the Partido Radical, and the role of Italians in protest movements and Argentinian civil wars. Finally, the essay seeks to respond to two central questions: why weren't foreigners given the right to citizenship and to vote? What were the effects on the political system?

  1. [Influenza in heterothermic animals].

    Science.gov (United States)

    Mancini, Dalva Assunção Portari; Mendonça, Rita Maria Zucatelli; Cianciarullo, Aurora Marques; Kobashi, Leonardo Setsuo; Trindade, Hermínio Gomes; Fernandes, Wilson; Pinto, José Ricardo

    2004-01-01

    The objective was to study Orthomyxovirus in heterothermic animals. Blood samples from snakes (genus Bothrops and Crotalus) and from toads and frogs (genus Bufo and Rana) were collected to evaluate the red cell receptors and antibodies specific to influenza virus by the hemagglutination and hemagglutination inhibition tests, respectively. Both snakes and toads kept in captivity presented receptors in their red cells and antibodies specific to either influenza virus type A (human and equine origin) or influenza type B. The same was observed with recently captured snakes. Concerning the influenza hemagglutination inhibition antibodies protective levels were observed in the reptiles' serum, against influenza type A and type B. Unlike the toads, 83.3% of the frogs presented mean levels of Ab 40HIU for some influenza strains. It was concluded that heterothermic animals could offer host conditions to the influenza virus and also susceptibility to the infection. PMID:15330057

  2. All-optical adder/subtractor based on tera-hertz optical asymmetric demultiplexer

    Institute of Scientific and Technical Information of China (English)

    Dilip Kumar Gayen; Rajat Kumar Pal; Jitendra Nath Roy

    2009-01-01

    An all-optical adder/subtractor (A/S) unit with the help of terahertz optical asymmetric demultiplexer (TOAD) is proposed.Tile all-optical A/S unit with a set of all-optical full-adders and optical exclusive-ORs (XORs),can be used to perform a fast central processor unit using optical hardware components.We try to exploit the advantages of TOAD-based optical switch to design an integrated all-optical circuit which can perform binary addition and subtraction.With computer simulation results confirming the described methods,conclusions are given.

  3. Výskyt a biotopové preference obojživelníků na bývalém tankovém cvičišti u Českých Budějovic

    OpenAIRE

    NĚMEC, Stanislav

    2011-01-01

    Submitted bachelor thesis deals with biotope preferences of amphibians. Experimental part of my work was carried out at former military tank ground near České Budějovice from March until June 2010. Biotope preferences were examined at these species: European Fire-bellied Toad, European tree frog, Agile Frog and Common toad. Since the end of military activity in 1990, there has been growing ecological succession which influences each of the species. The aim of my work was to find out what fact...

  4. Microelectronic neural bridge for signal regeneration and function rebuilding over two separate nerves

    International Nuclear Information System (INIS)

    According to the feature of neural signals, a micro-electronic neural bridge (MENB) has been designed. It consists of two electrode arrays for neural signal detection and functional electrical stimulation (FES), and a microelectronic circuit for signal amplifying, processing, and FES driving. The core of the system is realized in 0.5-μm CMOS technology and used in animal experiments. A special experimental strategy has been designed to demonstrate the feasibility of the system. With the help of the MENB, the withdrawal reflex function of the left/right leg of one spinal toad has been rebuilt in the corresponding leg of another spinal toad. According to the coherence analysis between the source and regenerated neural signals, the controlled spinal toad's sciatic nerve signal is delayed by 0.72 ms in relation to the sciatic nerve signal of the source spinal toad and the cross-correlation function reaches a value of 0.73. This shows that the regenerated signal is correlated with the source sciatic signal significantly and the neural activities involved in reflex function have been regenerated. The experiment demonstrates that the MENB is useful in rebuilding the neural function between nerves of different bodies. (semiconductor integrated circuits)

  5. 76 FR 78805 - Airworthiness Directives; Rolls-Royce plc (RR) RB211-Trent 800 Series Turbofan Engines

    Science.gov (United States)

    2011-12-20

    ... Register on August 22, 2011 (76 FR 52288). That NPRM proposed to correct an unsafe condition for the.... American also asserted that the estimate in the NPRM (76 FR 52288, August 22, 2011) of labor hours to...-AD685, which are referenced in the NPRM (76 FR 52288), do not include inspection criteria for the...

  6. Microelectronic neural bridge for signal regeneration and function rebuilding over two separate nerves

    Science.gov (United States)

    Xiaoyan, Shen; Zhigong, Wang; Xiaoying, Lü; Shushan, Xie; Zonghao, Huang

    2011-06-01

    According to the feature of neural signals, a micro-electronic neural bridge (MENB) has been designed. It consists of two electrode arrays for neural signal detection and functional electrical stimulation (FES), and a microelectronic circuit for signal amplifying, processing, and FES driving. The core of the system is realized in 0.5-μm CMOS technology and used in animal experiments. A special experimental strategy has been designed to demonstrate the feasibility of the system. With the help of the MENB, the withdrawal reflex function of the left/right leg of one spinal toad has been rebuilt in the corresponding leg of another spinal toad. According to the coherence analysis between the source and regenerated neural signals, the controlled spinal toad's sciatic nerve signal is delayed by 0.72 ms in relation to the sciatic nerve signal of the source spinal toad and the cross-correlation function reaches a value of 0.73. This shows that the regenerated signal is correlated with the source sciatic signal significantly and the neural activities involved in reflex function have been regenerated. The experiment demonstrates that the MENB is useful in rebuilding the neural function between nerves of different bodies.

  7. Microelectronic neural bridge for signal regeneration and function rebuilding over two separate nerves*

    Institute of Scientific and Technical Information of China (English)

    Shen Xiaoyan; Wang Zhigong; Lü Xiaoying; Xie Shushan; Huang Zonghao

    2011-01-01

    According to the feature of neural signals, a micro-electronic neural bridge (MENB) has been designed.It consists of two electrode arrays for neural signal detection and functional electrical stimulation (FES), and a microelectronic circuit for signal amplifying, processing, and FES driving. The core of the system is realized in 0.5-μm CMOS technology and used in animal experiments. A special experimental strategy has been designed to demonstrate the feasibility of the system. With the help of the MENB, the withdrawal reflex function of the left/right leg of one spinal toad has been rebuilt in the corresponding leg of another spinal toad. According to the coherence analysis between the source and regenerated neural signals, the controlled spinal toad's sciatic nerve signal is delayed by 0.72 ms in relation to the sciatic nerve signal of the source spinal toad and the cross-correlation function reaches a value of 0.73. This shows that the regenerated signal is correlated with the source sciatic signal significantly and the neural activities involved in reflex function have been regenerated. The experiment demonstrates that the MENB is useful in rebuilding the neural function between nerves of different bodies.

  8. Microelectronic neural bridge for signal regeneration and function rebuilding over two separate nerves

    Energy Technology Data Exchange (ETDEWEB)

    Shen Xiaoyan; Wang Zhigong; Xie Shushan; Huang Zonghao [Institute of RF- and OE-ICs, Southeast University, Nanjing 210096 (China); Lue Xiaoying, E-mail: zgwang@seu.edu.cn [Key Laboratory of Bioelectronics, Southeast University, Nanjing 210096 (China)

    2011-06-15

    According to the feature of neural signals, a micro-electronic neural bridge (MENB) has been designed. It consists of two electrode arrays for neural signal detection and functional electrical stimulation (FES), and a microelectronic circuit for signal amplifying, processing, and FES driving. The core of the system is realized in 0.5-{mu}m CMOS technology and used in animal experiments. A special experimental strategy has been designed to demonstrate the feasibility of the system. With the help of the MENB, the withdrawal reflex function of the left/right leg of one spinal toad has been rebuilt in the corresponding leg of another spinal toad. According to the coherence analysis between the source and regenerated neural signals, the controlled spinal toad's sciatic nerve signal is delayed by 0.72 ms in relation to the sciatic nerve signal of the source spinal toad and the cross-correlation function reaches a value of 0.73. This shows that the regenerated signal is correlated with the source sciatic signal significantly and the neural activities involved in reflex function have been regenerated. The experiment demonstrates that the MENB is useful in rebuilding the neural function between nerves of different bodies. (semiconductor integrated circuits)

  9. Proceedings of the Annual Meeting of the Association for Education in Journalism and Mass Communication (83rd, Phoenix, Arizona, August 9-12, 2000). Cultural and Critical Studies Division.

    Science.gov (United States)

    Association for Education in Journalism and Mass Communication.

    The Cultural and Critical Studies Division section of the proceedings contains the following 11 papers: "'Grimm' News Indeed--'Madstones,' Clever Toads, and Killer Tarantulas: Fairy-Tale Briefs in Wild West Newspapers" (Paulette Kilmer); "The First Amendment and the Doctrine of Corporate Personhood: Collapsing the Press-Corporation Distinction"…

  10. Kassinurme mägedes toimusid Elendili päeva pidustused ehk Tolkieni sõprade suvelaager / Ilmar Pajumägi

    Index Scriptorium Estoniae

    Pajumägi, Ilmar

    2005-01-01

    J. R. R. Tolkieni triloogia "Sõrmuste isand" sai tänavu 50 aastaseks. Sellega seoses korraldasid muinasjutusõbrad 18.-21. aug. Jõgeva lähedal Kassinurme mägedes LARPi (Live Action Role Play). Toimusid ka mitmed teemaga seotud töötoad, õpitoad ja loengud

  11. "mina usun sõna..." : [luuletused] / Maarja Kangro, Mart Kangur, Lauri Kitsnik jt

    Index Scriptorium Estoniae

    2007-01-01

    Sisu: "mina usun sõna..." ; Tüdruk heitis mulle silma (Silmapartii) ; "Helista siis mulle. Hoolimata sellest, mis kell ma täna magama..." ; Tärkab ; Toad ; "Tee sees on augud. Maa sees on augud..." ; "Puuk on perses. Ai-ai, valus on..." ; Päärätik ; Pliidikütt ; "Ukrainlannast põetaja..." ; Stereonurr ; "Luuletused..."

  12. Historical biogeography of Western Palaearctic pelobatid and pelodytid frogs: a molecular phylogenetic perspective

    NARCIS (Netherlands)

    Veith, M.; Fromhage, L.; Kosuch, J.; Vences, M.

    2006-01-01

    Spadefoot toads (Pelobates) and Parsley frogs (Pelodytes) are an enigmatic group of Western Palaearctic anurans. In the genus Pelobates, a fossorial lifestyle has enforced a conserved bauplan that masks their intraspecific evolutionary history. We used partial sequences of the mitochondrial 16S and

  13. MRI zoo

    DEFF Research Database (Denmark)

    Laustsen, Christoffer

    The basic idea was to use MRI to produce a sequence of 3D gray scale image slices of various animals, subsequentlyimaged with a clinical CT system. For this purpose, these animals were used: toad, lungfish, python snake and a horseshoe crab. Each animal was sacrificed according to standard proced...

  14. Our Zoo to You

    Science.gov (United States)

    Wickless, Mimi; Brooks, David W.; Abuloum, Amjad; Mancuso, Brian; Heng-Moss, Tiffany M.; Mayo, Lois

    2003-01-01

    An innovative zoo outreach program, Our Zoo to You, places zoo animals in local classrooms for extended observation periods. With guidance and support from zoo staff, students are able to safely experience a variety of animals, including geckos, snakes, legless lizards, horned toads, ringneck doves, ferrets, hedgehogs, African brown millipedes,…

  15. Myths.

    Science.gov (United States)

    Wheat, Maxwell Corydon, Jr.

    1982-01-01

    Deals with various myths about animals and plants. Discusses bats (not blind), toads (do not cause warts), dragonflies (will not sew up your mouth), horseshoe crabs (will not sting with their tails), owls (not so smart), and goldenrod (does not cause hayfever). (MH)

  16. Further report of the occurrence of tetrodotoxin in Atelopus species (family: Bufonidae).

    Science.gov (United States)

    Mebs, D; Yotsu-Yamashita, M; Yasumoto, T; Lötters, S; Schlüter, A

    1995-02-01

    In alcoholic extracts from museum samples of the toads Atelopus subornatus and A. peruensis tetrodotoxin and its analogues, 4-epitetrodotoxin and 4,9-anhydrotetrodotoxin were detected by fluorometric HPLC analysis, extending the list of amphibians containing this toxin. However, the toxin was not detected in samples of Melanophryniscus stelzneri, Dendrophryniscus minutus and Oreophrynella sp. PMID:7597728

  17. Predation of Molossus molossus (Pallas, 1766 (Chiroptera: Molossidae by Rhinella jimi (Stevaux, 2002 (Anura: Bufonidae in the Caatinga, Pernambuco, Brazil

    Directory of Open Access Journals (Sweden)

    Luiz Augustinho Menezes da Silva

    2010-06-01

    Full Text Available This communication is to report, through a fortuitous event, the predation of the bat Molossus molossus by the toad Rhinella jimi, on 29 May 2003 in the Caatinga, municipality of Orocó, state of Pernambuco, northeast Brazil.

  18. New Host and Distribution Records of the Leech Placobdella sophieaeOceguera-Figueroa et al., 2010 (Hirudinida: Glossiphoniidae)

    Science.gov (United States)

    Moser, William E.; Bowerman, Jay; Hovingh, Peter; Pearl, Christopher A.; Oceguera-Figueroa, Alajandro

    2014-01-01

    Placobdella sophieae Oceguera-Figueroa et al., 2010 (Hirudinida: Glossiphoniidae) is reported from Oregon, California, and British Columbia for the first time. New hosts reported for P. sophieae include Taricha granulosa (rough-skinned newt), Rana pretiosa (Oregon spotted frog), and Anaxyrus boreas (western toad). Placobdella sophieae exhibits relatively low host specificity and all amphibians occurring in the Pacific Northwest are potential hosts.

  19. What Do Amphibians Have to Offer?: Students Monitor and Map Amphibians in Local Pond Habitats

    Science.gov (United States)

    Eareckson, Lee Anne

    2002-01-01

    Students value participation in meaningful research. They feel empowered when they effect positive change in their communities. They also have a strong affinity for frogs and toads, although they vehemently deny this at the start of the school year. In addition, most students recognize the value of using computer technology to solve world…

  20. Täpne arhitektuur : ACADIA aastakonverents Cooper Unioni arhitektuurikoolis / Veronika Valk

    Index Scriptorium Estoniae

    Valk, Veronika, 1976-

    2010-01-01

    Septembris 2010 toimunud ACADIA aastakonverentsist New Yorgis. Konverents, töötoad ja näitus pakkusid parameetrilise projekteerimise spetsialistidele üle maailma lava, kus arhitektuuri uusi suundi arutada ja oma praktika üle mõtteid vahetada

  1. Leaping Lizards And Learning. In the Curriculum: Science

    Science.gov (United States)

    Petersen, Diane; Nelson, Cathi

    2004-01-01

    In the broad fields that stretch toward the horizon in the Columbia Basin region of Washington state, the land is just right for at least two purposes: growing dryland wheat and providing habitat for shorthorned lizards, also known as horny toads. Our elementary school, enrolling 150 children from this rural farming community, has become a hub for…

  2. Why are some mitochondria more powerful than others: insights from comparisons of muscle mitochondria from three terrestrial vertebrates.

    Science.gov (United States)

    Guderley, Helga; Turner, Nigel; Else, Paul L; Hulbert, A J

    2005-10-01

    We studied the molecular composition of muscle mitochondria to evaluate whether the contents of cytochromes or adenine nucleotide translocase (ANT) or phospholipid acyl compositions reflect differences in mitochondrial oxidative capacities. We isolated mitochondria from three vertebrates of similar size and preferred temperature, the rat (Rattus norvegicus), the cane toad (Bufo marinus) and the bearded dragon lizard (Pogona vitticeps). Mitochondrial oxidative capacities were higher in rats and cane toads than in bearded dragon, whether rates were expressed relative to protein, cytochromes or ANT. Inter-specific differences were least pronounced when rates were expressed relative to cytochrome A, a component of cytochrome C oxidase (CCO), or ANT. In mitochondria from rat and cane toad, cytochrome A was more abundant than C followed by B and then C(1), while in bearded dragon mitochondria, the cytochromes were present in roughly equal levels. Analysis of correlations between mitochondrial oxidative capacities and macromolecular components revealed that cytochrome A explained at least half of the intra- and inter-specific variability in substrate oxidation rates. ANT levels were an excellent correlate of state 3 rates while phospholipid contents were correlated with state 4 rates. As the % poly-unsaturation and the % 20:4n-6 in mitochondrial phospholipids were equivalent in toads and rats, and exceeded the levels in lizards, they may contribute to the inter-specific differences in oxidative capacities. We suggest that the numbers of CCO and ANT together with the poly-unsaturation of phospholipids explain the higher oxidative capacities in muscle mitochondria from rats and cane toads. PMID:16085440

  3. La identidad lingüística argentina a través de Borges y Puig

    Directory of Open Access Journals (Sweden)

    Thon, Sonia

    2010-02-01

    Full Text Available The identity of the Argentinian linguistic expression has been studied in depth by many literary critics and linguists who demonstrated the close relationship that exists between language, ideology, and socio-historic context; especially, when incorporating the concept of oral and colloquial language to the narrative discourse. We are basing this paper on the studies of authors such as: Beatriz Sarlo, Walter Bruno Berg, Wolf Oesterreicher, Maria Zulema Kulikowsi, and others in order to situate two Argentinian writers, Jorge Luis Borges and Manuel Puig, within their historic period in order to reveal how their personal and social anxieties impacted the perception of their work as representative of the Argentinian language.

    La identidad de la expresión lingüistica argentina ha sido estudiada a fondo por numerosos críticos literarios y lingüistas que demostraron la estrecha relación que existe entre lengua, ideología y contexto socio-histórico, especialmente al incorporarse al discurso narrativo el concepto de oralidad y “coloquialidad”. En este ensayo nos basaremos en estudios de autores tales como Beatriz Sarlo, Walter Bruno Berg, Wolf Oesterreicher, María Zulema Kulikowski, entre otros, para situar a dos escritores argentinos, Jorge Luis Borges y Manuel Puig, dentro de su época y revelar cómo sus ansiedades personales y sociales impactaron la percepción de su obra como representativa de lo que se considera el lenguaje argentino.

  4. El poder de la prensa, la prensa del poder : reflexión entorno al periodismo afroargentino

    Directory of Open Access Journals (Sweden)

    Jean Arsène Yao

    2004-09-01

    Full Text Available Le grand développement de la presse qui se produisit en Argentine à partir de 1850 se caractérisa en particulier par l'émergence d'une presse afro-argentine très active, dont l'objectif était de défendre les intérêts de la communauté noire. Cet article essaie de déterminer si les Argentins d'origine africaine prirent conscience du pouvoir de la presse écrite, comme moyen de divulgation de leurs idées. Par ailleurs, il met en évidence les accointances des journaux afroargentins avec la classe politique de l'époque, démontrant ainsi à quel point ils furent instrumentalisés par le pouvoir en place.El despegue periodístico que se produjo en Argentina durante la década de 1850 vio la aparición de una activa prensa afroargentina defensora de los intereses de la comunidad negra. Este artículo pretende analizar en qué medida los argentinos de origen africano fueron conscientes del poder de la prensa escrita como medio de divulgación de sus ideas. Subraya por otra parte el acercamiento de los periódicos afroargentinos a la clase política convirtiéndose en instrumentos del poder político.In the 1850's appeared an Afro-Argentinian activist press, which defended the black community interests. In this paper the author tries to evaluate if the Argentinians of African origin realized the full power of the written press as a way of spreading their ideas.Therefore, he explains the conversion of the Afro-Argentinians newspapers as political instruments.

  5. Revisiting Germani: the interpretation of modernity and the theory of action

    Directory of Open Access Journals (Sweden)

    José Maurício Domingues

    2005-01-01

    Full Text Available The work of the Italo-Argentinian sociologist Gino Germani has traditionally been classified as functionalist. However, recent studies have tended to change this perspective, emphasizing other important influences in his work. Against the backdrop of his broader theory, the objective of this article is to analyze, on the one hand, his perception, in the Latin American transition to modernity, of freedom as the essential issue in politics and daily life, and on the other, how this translates into a theory of action that remains overlooked, although only recently equivalents have been found in sociology, with his theory being more advanced in certain aspects than contemporary proposals in this direction.

  6. Sangre de amor correspondido: reflexões sobre um caso de autotradução

    Directory of Open Access Journals (Sweden)

    Andreia dos Santos Menezes

    2008-05-01

    Full Text Available Abstract: In this paper we will discuss about a case of autotranslation by the Argentinian writer Manuel Puig who elaboreteded himself the translation to Spanish of his novel Sangue de amor correspondido which was written in Portuguese. We will talk about the concepts of “retextualização”, model reader and model author, as well as ideal reader and ideal author. We will relate such concepts to the autotranslation for then relate them to the mentioned case of Puig, analyzing some examples of this in his novel.

  7. The Genetic Diversity of Influenza A Viruses in Wild Birds in Peru

    Science.gov (United States)

    Nelson, Martha I.; Pollett, Simon; Ghersi, Bruno; Silva, Maria; Simons, Mark P.; Icochea, Eliana; Gonzalez, Armando E.; Segovia, Karen; Kasper, Matthew R.; Montgomery, Joel M.; Bausch, Daniel G.

    2016-01-01

    Our understanding of the global ecology of avian influenza A viruses (AIVs) is impeded by historically low levels of viral surveillance in Latin America. Through sampling and whole-genome sequencing of 31 AIVs from wild birds in Peru, we identified 10 HA subtypes (H1-H4, H6-H7, H10-H13) and 8 NA subtypes (N1-N3, N5-N9). The majority of Peruvian AIVs were closely related to AIVs found in North America. However, unusual reassortants, including a H13 virus containing a PA segment related to extremely divergent Argentinian viruses, suggest that substantial AIV diversity circulates undetected throughout South America. PMID:26784331

  8. El silencio de las imágenes. Las ilustraciones a Una excursión a los indios ranqueles

    Directory of Open Access Journals (Sweden)

    Amanda Salvioni

    2015-07-01

    Full Text Available A Travel to the Ranquel Indians, by L.V. Mansilla, has been defined as the only text of Nineteenth Century Argentinian literature where the voices of natives clearly emerged. Nevertheless, in the history of its reception these voices were silenced by white society and the book was reduced to its anecdotal dimension. Paradoxically, the more the natives became mute, the more they were visible, converted into images, icons and mere representations. At the same time, more and more illustrations were included in the editions of the book. This essay aims to demonstrate how the illustrations were decisive in the repositioning and resemantization of the text.

  9. Networking for capturing and preserving existing knowledge

    International Nuclear Information System (INIS)

    In order to capture nuclear knowledge in key areas that might be lost due to organizational evolution and the ageing of human resources, CNEA has promoted three projects with specific strategic objectives: LICREX (Research Reactors Knowledge Book), knowledge preservation of the Atucha type reactor and CLAMN (Nuclear Medicine Knowledge Latin American Net). Using knowledge management techniques and taking advantage of Information and Communications Technologies (ICT) corporative resources, these projects are intended to protect, preserve and capture a part of the intellectual property generated by the Argentinian nuclear sector. (author)

  10. Origen y evolucion de la manufactura en el interior. El caso de Bahía Blanca

    OpenAIRE

    Viego Valentina

    2005-01-01

    Bahía Blanca has been posed as the main Southern city of the country (both in population and economic terms) by various works in the field of economic geography. In particular, it has been emphasized its leading manufacturing sector (historically oriented to exports) and its role as center of supply for most Patagonian towns. This economic function has been spreaded by the slogan “Bahía Blanca, port and door of Argentinian South”, targeted to unify heterogeneous visions about the city role in...

  11. Description of research reactors in countries participating in the TC Regional Project RLA/4/014: Argentina

    International Nuclear Information System (INIS)

    Argentina has six operating research reactors that can be divided into two groups. The first group comprises the reactors that operate according to a regular schedule, which includes research reactors RA-1, RA-3 and RA-6. The second group comprises the critical assemblies RA-0, RA-4 and RA-8. Another reactor, RA-2, was shut down in 1983, and currently it is in the process of decommissioning. With the exception of RA-4, all Argentine research reactors use fuel elements fabricated in the country. The fuel elements of RA-4 were donated by Germany. What follows is a brief description of all seven Argentinian research reactors

  12. Las armas de la conquista. Presencia de armas de fuego en sitios coloniales de Argentina

    Directory of Open Access Journals (Sweden)

    Ana Igareta

    2013-12-01

    Full Text Available Objects used as weapons by the man had interested archaeologists worldwide since the early times of the discipline. Cultural sequences had been defined using the evolution arms as one of the relevant material indicators of social development. Argentinian archaeology has an extensive tradition of prehistoric weapons studies, but little attention has been accorded to the repertoire of arms -particulary firearmsused during colonial confrontations between Spanish soldiers and native population. The current paper briefly summarizes the main findings of colonial firearms remains in Argentina as well as reviews potential difficulties during archaeological identification of those remains.

  13. 15 June 2009 - President of the Argentine Nation C. Fernández visiting ATLAS experimental area.

    CERN Multimedia

    Maximilien Brice

    2009-01-01

    Tirage 1:President of the Argentine Nation, C. Fernández and Minister of Science, Technology and Innovative Production,L. Barañao Tirage 2-8:Arrival greetings Tirage 9-12:Introduction to CERN's activities by Director-General, R. Heuer Tirage 13-15:Signature of the guest book Tirage 16-25:M. Benedetti,R. Heuer and L.Barañao sit for the signature of the Agreement Tirage 26-33: Meeting with Argentinian scientists at CERN

  14. Historias intramuros

    OpenAIRE

    Torres, Victoria

    2013-01-01

    The articles deals with a series of Argentinian novels published after 2001 that all revolve around the same theme of the gated community. In my reading, I will relate the different texts to actual criminal cases and discuss them in the context of curreng trends in criminal fiction. El artículo analiza novelas argentinas posteriores al 2001 cuyo escenario son los barrios cerrados y las relaciona con los casos policiales reales y con las actuales formas de narrar del género policial.

  15. Problems of implementing a large contract abroad: the Cordoba nuclear power station

    Energy Technology Data Exchange (ETDEWEB)

    Caruso, P.

    1984-11-01

    The building of Argentina's second nuclear power station proved to be a true test of project-management skills: the contract was to be a joint effort between an Italian and a Canadian company, to be implemented in a country thousands of miles away; the Argentinian government changed four times during the course of the project; and the local currency was always unstable and unpredictable. The various difficulties that arose, and how they were solved, are described, and the role of the project management is evaluated.

  16. Problems of implementing a large contract abroad: the Cordoba nuclear power station

    International Nuclear Information System (INIS)

    The building of Argentina's second nuclear power station proved to be a true test of project-management skills: the contract was to be a joint effort between an Italian and a Canadian company, to be implemented in a country thousands of miles away; the Argentinian government changed four times during the course of the project; and the local currency was always unstable and unpredictable. The various difficulties that arose, and how they were solved, are described, and the role of the project management is evaluated. (author)

  17. Kikuchi–Fujimoto disease and systemic lupus erythematosus

    Science.gov (United States)

    Baenas, Diego F; Diehl, Fernando A; Haye Salinas, María J; Riva, Verónica; Diller, Ana; Lemos, Pablo A

    2016-01-01

    Kikuchi–Fujimoto disease, or histiocytic necrotizing lymphadenitis, is an infrequent idiopathic disorder. It has been associated with autoimmune disorders, of which systemic lupus erythematosus is the most outstanding. The basis of its diagnosis relies on the histological examination of lymph nodes, which typically reveals necrosis surrounded by histiocytes with crescentic nucleus, immunoblasts and plasma cells, and absence of neutrophils. We report the case of a 27-year-old Argentinian female patient without any relevant past medical history to demonstrate the correlation between Kikuchi–Fujimoto disease and systemic lupus erythematosus. PMID:27418858

  18. Territorial (DisOrdering in Salta. A look into the context prior to the Territory Planning of Native Forests in the Province of Salta

    Directory of Open Access Journals (Sweden)

    Mariana Schmidt

    2014-04-01

    Full Text Available In this article, we look into the characteristics of production in the Province of Salta during the years prior to the approval of National Law No. 26,331 of "Minimum Budget for Environmental Protection of Native Forests" and to the implementation of policies of Territory Planning of Native Forests. We begin briefly describing the transformations occurred in the Argentinian countryside since the early 1970, and go on characterizing such process and its specific features in the east of Salta, where the agricultural border in the last decades has rapidly gained ground over territories in the past considered marginal for agricultural and livestock business production

  19. Paisaje sociopolítico y beligerancia en el valle de Hualfín (Catamarca, Argentina.

    Directory of Open Access Journals (Sweden)

    Federico Wynveldt.

    2009-01-01

    Full Text Available In this article we propose an operative definition of landscape that includes not only its material aspects but also its capability to signify and direct social relationships. This concept is applied, focusing on the spatial dimension, to the study of three archaeological sites in the Argentinian Northwest, belonging to the Regional Development Period (1000-1480/Inka (1480-1535. Analyzing information related to the landscape, we interpret sociopolitical aspects concerning the inhabitants of the Hualfin Valley in a period characterized by confict and warfare.

  20. Consideraciones biogeográficas y ecológicas de equinodermos arquibentónicos de Chile Central (com excepción de crinoidea

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    Héctor Andrade Vasquez

    1980-12-01

    Full Text Available 30 echinoderm species (the crinoias excepted have been recorded from the archibenthos off Central Chile. Samples were taken at 5 stations (from Los Vilos to Quíntero. 250-450 m depth range, every 15 days for one year. The concept of Region or Province, usually related to the intertital fauna from high latitudes are showed to be impractical using them with archibenthal echinoderms. The presence oj some species that had been registered as characteristic from the Antarctic Region and/or present in the Argentinian and Magellanic Province is related with the Antarctic Intermediate Water Mass, which is at the capture depth in the sampled area.

  1. QUBIC Experiment

    CERN Document Server

    Stolpovskiy, Mikhail

    2016-01-01

    QUBIC is a ground-based experiment, currently under construction, that uses the novel bolometric interferometry technology. It is dedicated to measure the primordial B-modes of CMB. As a bolometric interferometer, QUBIC has high sensitivity and good systematics control. Dust contamination is controlled by operating with two bands -- 150 and 220 GHz. There are two possible sites for QUBIC: either Concordia station in Antarctic or in the Argentinian Puna desert. It is planned to see the first light in 2018-2019.

  2. CAPITAL INTELECTUAL Y COMPETENCIAS DISTINTIVAS EN PYMES MADERERAS DE ARGENTINA

    Directory of Open Access Journals (Sweden)

    Carlos M. F-Jardon

    2014-10-01

    Full Text Available In the knowledge economy, intellectual capital is increasingly becoming important as a source of core competences. A core competence is obtained by combining internal and external factors of the company by means of the strategy to generate better performance than its competitors. The Argentinian wood SMEs often have specific characteristics and, in particular, a limited intellectual capital. Consequently, it is expected that the process of establishing core competences is different. This paper analyzes the characteristics of that process. The results show how they organize their resources and capabilities to provide their competitiveness. This competitiveness leads to better organizational performance, but does not directly affect economic performance.

  3. Rappresentazioni e (intraducibilità del delirio: Informe sobre ciegos di Alberto Breccia

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    Susanna Nanni

    2015-07-01

    Full Text Available The essay proposes an analysis of the relationship between text and images in Informe sobre ciegos (1991 by Alberto Breccia. In his obstinate renunciation to unnecessary words, or surplus signs, and by employing graphic devices that convey a "telluric and formless" world, Breccia interprets and illustrates – without making it comprehensible – the self-destructive delirious state of Fernando Vidal, one of the most controversial and fascinating characters in Argentinian literature. In particular, the essay focuses on the conspiracy – at the level of both form and content – and on the graphic (untranslatability of his delirium.

  4. Feminist Yönetmen Bemberg’de Anne-Kız İlişkisi

    OpenAIRE

    Derya Nacaroglu

    2010-01-01

    In this study an Argentinian Feminist director Maria Lusia Bemberg‟s film I Don’t Want to Talk About it (1993) is analyzed. The specific focus is on how women are evaluated within the framework of a mother-daughter relationship. It is argued that Bemberg presents a feminist treatment of how a woman responds to the pressure present in a patriarchal family system. As a result, the mother‟s struggle to show her disabled daughter to society like a “normal” person illustrates the pressure and prob...

  5. Feminist Yönetmen Bemberg’de Anne-Kız İlişkisi

    Directory of Open Access Journals (Sweden)

    Derya Nacaroglu

    2010-09-01

    Full Text Available In this study an Argentinian Feminist director Maria Lusia Bemberg‟s film I Don’t Want to Talk About it (1993 is analyzed. The specific focus is on how women are evaluated within the framework of a mother-daughter relationship. It is argued that Bemberg presents a feminist treatment of how a woman responds to the pressure present in a patriarchal family system. As a result, the mother‟s struggle to show her disabled daughter to society like a “normal” person illustrates the pressure and problem created by a daughter‟s independence.

  6. The promotional value of motorsport culture. A sociological invstigation of the FIA World Rally Championship

    OpenAIRE

    2014-01-01

    From the snow and ice of Scandinavia to the glamour of Monte Carlo, from the heat of Kenya to the thin air in the Argentinian mountainsides, the FIA World Rally Championship (WRC) has served up passionate motorsport drama since its inauguration in its current form in 1973. During that time the sport has transformed from a little-known series to a pop-cultural roadshow worth millions of euros, with 13 rallies scattered around the world and more than 600 million TV-viewers annually. This develo...

  7. Sociologia, peronismo e esquerda na Argentina Sociology, peronism and left in Argentina

    Directory of Open Access Journals (Sweden)

    Carlos R. Etulain

    2007-05-01

    Full Text Available O trabalho discute, o papel do peronismo e os problemas político-ideológicos que ele coloca para a esquerda Argentina. Busca, também, apresentar os principais elementos para uma análise da esquerda frente ao fenômeno do peronismo. Palavras-chave: Peronismo. Esquerda. Trabalhadores. Movimentos sociais. Classes sociais. Capitalismo. Política. This paper presents the role of Peronism and the ideological political problems to be confronted by the Argentinian leftists. It also presents the most important elements for the leftists to analyse the fenomenum of Peronism. Keywords: Peronism. Left. Workers. Social movements. Social classes. Capitalism. Politics.

  8. Breeding biology of Grey eagle-buzzard (Geranoaetus melanoleucos) population in Patagonia

    OpenAIRE

    Hiraldo, F.; Donázar, José A.; Ceballos, Olga; Travaini, Alejandro; Bustamante, Javier; Funes, Martín

    1995-01-01

    We studied the breeding performance of a Grey Eagle-Buzzard (Geranoaetus melanoleucus) population in a region of northern Argentinian Patagonia where two different habitats occur; the mountains near the Andean cordiBera and the plains where shrub-steppes predominate. Mean eagle density was I pair/I 9 km2 (N = 44), with higher densities occuring in the plains (1 pair/13.2 km2. N — 17) than in the mountains (1 pair/22.7 km2. N = 27). We located four communal roosts, with ...

  9. Datos para una historia de la psicologia experimental Argentina (hasta 1930

    Directory of Open Access Journals (Sweden)

    Mauricio R. Papini

    1976-01-01

    Full Text Available A presentation is made of the early origins of experimental prychology .ín Argentina from 1880 to 1930. During thís 50 year perlod the first chaira of experimental psychology were created in the country. Horacio G. Píñero founded the 6rst experimental psYchology laboratory in 11198,- al the Colegio Nacional of Buenos Aires. During tbis period ltriiger. Dumas. Janet and Kohler visited Argentina. After 1980 Argentinian psychology turned to Irratíonalism, and away from experímentatíon.

  10. Optimisation of an oviposition protocol employing human chorionic and pregnant mare serum gonadotropins in the Barred Frog Mixophyes fasciolatus (Myobatrachidae

    Directory of Open Access Journals (Sweden)

    Clulow John

    2012-08-01

    Full Text Available Abstract Background Protocols for the hormonal induction of ovulation and oviposition are essential tools for managing threatened amphibians with assisted reproduction, but responses vary greatly between species and even broad taxon groups. Consequently, it is necessary to assess effectiveness of such protocols in representative species when new taxa become targets for induction. The threatened genus Mixophyes (family Myobatrachidae has amongst the highest proportion of endangered species of all the Australian amphibians. This study developed and optimised the induction of oviposition in a non-threatened member of this taxon, the great barred frog (Mixophyes fasciolatus. Methods Gravid female M. fasciolatus were induced to oviposit on one or more occasions by administration of human chorionic gonadotropin (hCG with or without priming with pregnant mare serum gonadotropin (PMSG. Treatments involved variations in hormone doses and combinations (administered via injection into the dorsal lymph sacs, and timing of administration. Pituitary homogenates from an unrelated bufonid species (Rhinella marina were also examined with hCG. Results When injected alone, hCG (900 to 1400 IU induced oviposition. However, priming with two time dependent doses of PMSG (50 IU, 25 IU increased responses, with lower doses of hCG (200 IU. Priming increased response rates in females from around 30% (hCG alone to more than 50% (p = 0.035, and up to 67%. Increasing the interval between the first PMSG dose and first hCG dose from 3 to 6 days also produced significant improvement (p Conclusions This study found that M. fasciolatus is amongst the few amphibian species (including Xenopus (Silurana and some bufonids that respond well to the induction of ovulation utilising mammalian gonadotropins (hCG. The optimal protocol for M. fasciolatus involved two priming doses of PMSG (50 IU and 25 IU administered at 6 and 4 days respectively, prior to two doses of hCG (100 IU, 24

  11. Pulmonary compliance and lung volume varies with ecomorphology in anuran amphibians: implications for ventilatory-assisted lymph flux.

    Science.gov (United States)

    Hedrick, Michael S; Hillman, Stanley S; Drewes, Robert C; Withers, Philip C

    2011-10-01

    Vertical movement of lymph from ventral regions to the dorsally located lymph hearts in anurans is accomplished by specialized skeletal muscles working in concert with lung ventilation. We hypothesize that more terrestrial species with greater lymph mobilization capacities and higher lymph flux rates will have larger lung volumes and higher pulmonary compliance than more semi-aquatic or aquatic species. We measured in situ mean and maximal compliance (Δvolume/Δpressure), distensibility (%Δvolume/Δpressure) and lung volume over a range of physiological pressures (1.0 to 4.0 cmH(2)O) for nine species of anurans representing three families (Bufonide, Ranidae and Pipidae) that span a range of body masses and habitats from terrestrial to aquatic. We further examined the relationship between these pulmonary variables and lymph flux for a semi-terrestrial bufonid (Rhinella marina), a semi-aquatic ranid (Lithobates catesbeianus) and an aquatic pipid (Xenopus laevis). Allometric scaling of pulmonary compliance and lung volume with body mass showed significant differences at the family level, with scaling exponents ranging from ∼0.75 in Bufonidae to ∼1.3 in Pipidae. Consistent with our hypothesis, the terrestrial Bufonidae species had significantly greater pulmonary compliance and greater lung volumes compared with semi-aquatic Ranidae and aquatic Pipidae species. Pulmonary distensibility ranged from ∼20 to 35% cmH(2)O(-1) for the three families but did not correlate with ecomorphology. For the three species for which lymph flux data are available, R. marina had a significantly higher (P<0.001) maximal compliance (84.9±2.7 ml cmH(2)O(-1) kg(-1)) and lung volume (242.1±5.5 ml kg(-1)) compared with L. catesbeianus (54.5±0.12 ml cmH(2)O(-1) kg(-1) and 139.3±0.5 ml kg(-1)) and X. laevis (30.8±0.7 ml cmH(2)O(-1) kg(-1) and 61.3±2.5 ml kg(-1)). Lymph flux rates were also highest for R. marina, lowest for X. laevis and intermediate in L. catesbeianus. Thus, there is

  12. La construcción de la subjetividad. El impacto de las políticas sociales

    Directory of Open Access Journals (Sweden)

    Nora Mabel Briuoli

    2009-12-01

    Full Text Available El objetivo de este trabajo es abordar el modo complejo en que la realidad social impacta en la construcción de la subjetividad. Los ejes de análisis son los siguientes: La Construcción De La Subjetividad. Las funciones simbólicas que permiten dicho proceso psíquico. Los Nuevos Sujetos y Territorios de la precariedad y la desafiliación. Los Lazos Sociales. Nuevos roles. Declive de las instituciones y de los dispositivos de la Ley. Viejas Problemáticas planteadas Como Nuevas en el contexto actual: Desocupación, robo, adicciones, problemáticas escolares, los hijos de desaparecidos. Lo complejo de la realidad a la que nos enfrentamos en la vida cotidiana. Necesidad de revisar nuestras miradas e intervenciones.___________________ABSTRACT:The research has the purpose of analyzing the influence of the Army institutions during the return to the argentinian democratic system in 1983. It tries to study the way in which the Army influenced in the speeches of the electoral campaign, the political decisions put in practice by the Alfonsin Administration in military order, the Argentinian Forces imbalances, the disposition (or not of subordinating to the civil power and their role during the mutinies between 1987 and 1989, ideas that will allow an adequate analysis of the abilities and fragilities of the government strategies in the military sphere.

  13. Fuerzas Armadas y transición democrática. Argentina, 1983-1989

    Directory of Open Access Journals (Sweden)

    Andrés Alberto Masi Rius

    2009-12-01

    Full Text Available El presente trabajo procura analizar el grado de influencia que las instituciones militares tuvieron en la apertura democrática argentina en 1983. Se analizará la modalidad en que las Fuerzas Armadas influyeron en los discursos en la campaña electoral, las medidas implementadas por la Administración Alfonsín en materia militar, los desequilibrios internos del Ejército Argentino, la disposición (o no de las Fuerzas de subordinarse al poder civil y el rol que las mismas desempeñaron en los levantamientos de 1987 y 1989, líneas que permitirán una adecuado análisis de los aciertos y fragilidades de las estrategias de gobierno en la esfera castrense.______________________ABSTRACT:The research has the purpose of analyzing the influence of the Army institutions during the return to the argentinian democratic system in 1983. It tries to study the way in which the Army influenced in the speeches of the electoral campaign, the political decisions put in practice by the Alfonsin Administration in military order, the Argentinian Forces imbalances, the disposition (or not of subordinating to the civil power and their role during the mutinies between 1987 and 1989, ideas that will allow an adequate analysis of the abilities and fragilities of the government strategies in the military sphere.

  14. The structure of zetekitoxin AB, a saxitoxin analog from the Panamanian golden frog Atelopus zeteki: a potent sodium-channel blocker.

    Science.gov (United States)

    Yotsu-Yamashita, Mari; Kim, Yong H; Dudley, Samuel C; Choudhary, Gaurav; Pfahnl, Arnold; Oshima, Yasukatsu; Daly, John W

    2004-03-30

    Bufonid anurans of the genus Atelopus contain both steroidal bufadienolides and various guanidinium alkaloids of the tetrodotoxin class. The former inhibit sodium-potassium ATPases, whereas the latter block voltage-dependent sodium channels. The structure of one guanidinium alkaloid, zetekitoxin AB, has remained a mystery for over 30 years. The structure of this alkaloid now has been investigated with a sample of approximately 0.3 mg, purified from extracts obtained decades ago from the Panamanian golden frog Atelopus zeteki. Detailed NMR and mass spectral analyses have provided the structure and relative stereochemistry of zetekitoxin AB and have revealed that it is an analog of saxitoxin. The proposed structure is characterized by richness of heteroatoms (C16H25N8O12S) and contains a unique 1,2-oxazolidine ring-fused lactam, a sulfate ester, and an N-hydroxycarbamate moiety. Zetekitoxin AB proved to be an extremely potent blocker of voltage-dependent sodium channels expressed in Xenopus oocytes. The IC50 values were 280 pM for human heart channels, 6.1 pM for rat brain IIa channels, and 65 pM for rat skeletal muscle channels, thus being roughly 580-, 160-, and 63-fold more potent at these channels than saxitoxin. PMID:15070720

  15. Choosy Cannibals Preferentially Consume Siblings with Relatively Low Fitness Prospects.

    Science.gov (United States)

    Dugas, Matthew B; McCormack, Larkin; Gadau, Alice; Martin, Ryan A

    2016-07-01

    When an individual can selfishly cannibalize a relative or altruistically set it free, the benefits of altruism will be positively associated with the relative's fitness prospects (the benefits it receives from altruism). We tested the prediction that altruism should be preferentially directed toward high-quality relatives using larvae of the New Mexican spadefoot toad (Spea multiplicata), a species in which tadpoles plastically express omnivore and carnivore ecomorphs. In a no-choice design, we presented carnivores with sibling or nonsibling omnivores varying in developmental stage, which is positively associated with survival in this toad's ephemeral larval environment. There was a significant interaction between relatedness and developmental stage on the probability of cannibalism: carnivores were overall more likely to cannibalize less developed omnivores, but this effect was exaggerated when the potential victim was a sibling. This evidence that altruists favor relatives with high fitness prospects highlights the numerous factors shaping altruism's payoffs. PMID:27322127

  16. Cryptosporidia: epicellular parasites embraced by the host cell membrane.

    Science.gov (United States)

    Valigurová, Andrea; Jirků, Miloslav; Koudela, Bretislav; Gelnar, Milan; Modrý, David; Slapeta, Jan

    2008-07-01

    The ultrastructure of two gastric cryptosporidia, Cryptosporidium muris from experimentally infected rodents (Mastomys natalensis) and Cryptosporidium sp. 'toad' from naturally infected toads (Duttaphrynus melanostictus), was studied using electron microscopy. Observations presented herein allowed us to map ultrastructural aspects of the cryptosporidian invasion process and the origin of a parasitophorous sac. Invading parasites attach to the host cell, followed by gradual envelopment, with the host's cell membrane folds, eventually forming the parasitophorous sac. Cryptosporidian developmental stages remain epicellular during the entire life cycle. The parasite development is illustrated in detail using high resolution field emission scanning electron microscopy. This provides a new insight into the ultrastructural detail of host-parasite interactions and species-specific differences manifested in frequency of detachment of the parasitophorous sac, radial folds of the parasitophorous sac and stem-formation of the parasitised host cell. PMID:18158154

  17. Studies of Annual and Seasonal Variations in Four Species of Reptiles and Amphibians at Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Keller, D.C.; Nelson, E.I.; Mullen, M.A.; Foxx, T.S.; Haarmann, T.K.

    1998-07-01

    Baseline studies of reptiles and amphibians of the Pajarito wetlands at Los Alamos National Laboratory have been conducted by the Ecology group since 1990. With the data gathered from 1990-1997 (excluding 1992), we examined the annual and seasonal population changes of four species of reptiles and amphibians over the past seven years. The four species studied are the Woodhouse toad (Bufo woodhousii), the western chorus frog (Pseudacris triseriata), the many-lined skink (Eunzeces nudtivirgatus), and the plateau striped whiptail lizard (Cnemidophorus velox). Statistical analyses indicate a significant change on a seasonal basis for the western chorus frog and the many-lined skink. Results indicate a significant difference in the annual population of the Woodhouse toad.

  18. Studies of annual and seasonal variations in four species of reptiles and amphibians at Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, E.I.; Haarmann, T.; Keller, D.C.; Foxx, T.

    1998-11-01

    Baseline studies of reptiles and amphibians of the Pajarito wetlands at Los Alamos National Laboratory have been conducted by the Ecology group since 1990. With the gathered data from 1990--1997 (excluding 1992), they plan to determine if patterns can be found in the annual and seasonal population changes of four species of reptiles and amphibians over the past seven years. The four species studied are the Woodhouse toad, the western chorus frog, the many-linked skink, and the plateau striped whiptail lizard. Statistical analysis results show that significant changes occurred on a seasonal basis for the western chorus frog and the many-lined skink. Results indicate a significant difference in the annual population of the Woodhouse toad.

  19. Anticancer potential of animal venoms and toxins.

    Science.gov (United States)

    Gomes, Antony; Bhattacharjee, Pushpak; Mishra, Roshnara; Biswas, Ajoy K; Dasgupta, Subir Chandra; Giri, Biplab

    2010-02-01

    Anticancer drug development from natural resources are ventured throughout the world. Animal venoms and toxins a potential bio resource and a therapeutic tool were known to man for centuries through folk and traditional knowledge. The biodiversity of venoms and toxins made it a unique source of leads and structural templates from which new therapeutic agents may be developed. Venoms of several animal species (snake, scorpion, toad, frog etc) and their active components (protein and non protein toxins, peptides, enzymes, etc) have shown therapeutic potential against cancer. In the present review, the anticancer potential of venoms and toxins from snakes, scorpions, toads and frogs has been discussed. Some of these molecules are in the clinical trials and may find their way towards anticancer drug development in the near future. The implications of combination therapy of natural products in cancer have been discussed. PMID:20455317

  20. The Educational Pipelinie for Women in Biology: No Longer Leaking?

    OpenAIRE

    Luckenbill-Edds, Louise

    2002-01-01

    Describing the past 30 years of progress toward gender equity in science, one observer wrote: "Although optimistic about future prospects, I must also point out some daunting toads and serpents lurking in the gardens of science. These challenge the rising generation of young scientists to be no less intrepid [that past activists who catalyzed change]" (Herschbach 1999, p. 66). The failure of the sciences to attract and retain women has meant a loss of diversity, as well as a loss of talent ...