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Sample records for amazonian leaflitter frog

  1. Effects of forest fragmentation and habitat degradation on West African leaf-litter frogs

    NARCIS (Netherlands)

    Hillers, A.; Veith, M.; Rödel, M.-O.

    2008-01-01

    Habitat degradation alters the dynamics and composition of anuran assemblages in tropical forests. The effects of forest fragmentation on the composition of anuran assemblages are so far poorly known. We studied the joint influence of forest fragmentation and degradation on leaf-litter frogs. We

  2. Leaf-litter amount as a factor in the structure of a ponerine ants community (Hymenoptera, Formicidae, Ponerinae in an eastern Amazonian rainforest, Brazil

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    Alexandro Herbert dos Santos Bastos

    2011-12-01

    Full Text Available Leaf-litter amount as a factor in the structure of a ponerine ants community (Hymenoptera, Formicidae, Ponerinae in an eastern Amazonian rainforest, Brazil. Leaf-litter may be an important factor in structuring ponerine ant communities (Hymenoptera, Formicidae, Ponerinae in tropical rainforests. We specifically examined how leaf-litter affects the structure of a ponerine ant community in primary Amazonian rainforest sites at the Ferreira Penna Scientific Station, Pará, Brazil. A total of 53 species belonging to eight genera of three ponerine tribes were collected with mini-Winkler extractors. The amount of leaf-litter positively affected the abundance and richness of the ponerine ant community, and also influenced species composition. Nearby samples often had low species similarity, especially when adjacent samples differed in the amount of leaf-litter. Leaf-litter availability in Amazonian primary forests is a key factor for distribution of ground-dwelling ponerine species, even at small scales.

  3. Food niche overlap between two sympatric leaf-litter frog species from Central Amazonia

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    Leandro Talione Sabagh

    2012-02-01

    Full Text Available We studied the feeding habits and similarities in the diet of two sympatric and syntopic Amazonian frog species, Anomaloglossus stepheni (Aromobatidae and Leptodactylus andreae (Leptodactylidae in a forested area in Central Amazonia. The breadth of the trophic niche of these species was 5.89 and 3.75, respectively, and approximately 85% of their diets were similar. Ants were main food item in the diets of both frog species. The coexistence between these frog species may be facilitated by the significant differences in the size of their mouths. This difference allows them to consume preys items of different sizes.

  4. Evidence for an intrinsic factor promoting landscape divergence in Madagascan leaf-litter frogs

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    Katharina C. Wollenberg Valero

    2015-05-01

    Full Text Available The endemic Malagasy frog radiations are an ideal model system to study patterns and processes of speciation in amphibians. Large-scale diversity patterns of these frogs, together with other endemic animal radiations, led to the postulation of new and the application of known hypotheses of species diversification causing diversity patterns in this biodiversity hotspot. Both extrinsic and intrinsic factors have been studied in a comparative framework, with extrinsic factors usually being related to the physical environment (landscape, climate, river catchments, mountain chains, and intrinsic factors being clade-specific traits or constraints (reproduction, ecology, morphology, physiology. Despite some general patterns emerging from such large-scale comparative analyses, it became clear that the mechanism of diversification in Madagascar may vary among clades, and may be a multifactorial process. In this contribution, I test for intrinsic factors promoting population-level divergence within a clade of terrestrial, diurnal leaf-litter frogs (genus Gephyromantis that has previously been shown to diversify according to extrinsic factors. Landscape genetic analyses of the microendemic species G. enki and its widely distributed, larger sister species G. boulengeri over a rugged landscape in the Ranomafana area shows that genetic variance of the smaller species cannot be explained by landscape resistance alone. Both topographic and riverine barriers are found to be important in generating this divergence. This case study yields additional evidence for the probable importance of body size in lineage diversification.

  5. Sexual selection drives speciation in an Amazonian frog

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    Boul, K.E.; Funk, W.C.; Darst, C.R.; Cannatella, D.C.; Ryan, M.J.

    2007-01-01

    One proposed mechanism of speciation is divergent sexual selection, whereby divergence in female preferences and male signals results in behavioural isolation. Despite the appeal of this hypothesis, evidence for it remains inconclusive. Here, we present several lines of evidence that sexual selection is driving behavioural isolation and speciation among populations of an Amazonian frog (Physalaemus petersi). First, sexual selection has promoted divergence in male mating calls and female preferences for calls between neighbouring populations, resulting in strong behavioural isolation. Second, phylogenetic analysis indicates that populations have become fixed for alternative call types several times throughout the species' range, and coalescent analysis rejects genetic drift as a cause for this pattern, suggesting that this divergence is due to selection. Finally, gene flow estimated with microsatellite loci is an average of 30 times lower between populations with different call types than between populations separated by a similar geographical distance with the same call type, demonstrating genetic divergence and incipient speciation. Taken together, these data provide strong evidence that sexual selection is driving behavioural isolation and speciation, supporting sexual selection as a cause for speciation in the wild. ?? 2006 The Royal Society.

  6. Factors affecting the abundance of leaf-litter arthropods in unburned and thrice-burned seasonally-dry Amazonian forests.

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    Juliana M Silveira

    Full Text Available Fire is frequently used as a land management tool for cattle ranching and annual crops in the Amazon. However, these maintenance fires often escape into surrounding forests, with potentially severe impacts for forest biodiversity. We examined the effect of experimental fires on leaf-litter arthropod abundance in a seasonally-dry forest in the Brazilian Amazon. The study plots (50 ha each included a thrice-burned forest and an unburned control forest. Pitfall-trap samples were collected at 160 randomly selected points in both plots, with sampling stratified across four intra-annual replicates across the dry and wet seasons, corresponding to 6, 8, 10 and 12 months after the most recent fire. Arthropods were identified to the level of order (separating Formicidae. In order to better understand the processes that determine arthropod abundance in thrice-burned forests, we measured canopy openness, understory density and litter depth. All arthropod taxa were significantly affected by fire and season. In addition, the interactions between burn treatment and season were highly significant for all taxa but Isoptera. The burned plot was characterized by a more open canopy, lower understory density and shallower litter depth. Hierarchical partitioning revealed that canopy openness was the most important factor explaining arthropod order abundances in the thrice-burned plot, whereas all three environmental variables were significant in the unburned control plot. These results reveal the marked impact of recurrent wildfires and seasonality on litter arthropods in this transitional forest, and demonstrate the overwhelming importance of canopy-openness in driving post-fire arthropod abundance.

  7. Offering offspring as food to cannibals: oviposition strategies of Amazonian poison frogs (Dendrobates ventrimaculatus)

    OpenAIRE

    Poelman, E.H.; Dicke, M.

    2007-01-01

    Species utilizing distinct resources for offspring production often show plasticity in reproductive strategies as a function of resource quality. For species using ephemeral pools, strategies are mainly shaped by a time constraint related to pool stability, resource availability and the colonizing community. We studied reproductive strategies in Amazonian poison frogs (Dendrobates ventrimaculatus) that are characterized by oviposition in distinct, small and resource-limited water bodies in le...

  8. Large-scale phylogenetic analyses provide insights into unrecognized diversity and historical biogeography of Asian leaf-litter frogs, genus Leptolalax (Anura: Megophryidae).

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    Chen, Jin-Min; Poyarkov, Nikolay A; Suwannapoom, Chatmongkon; Lathrop, Amy; Wu, Yun-He; Zhou, Wei-Wei; Yuan, Zhi-Yong; Jin, Jie-Qiong; Chen, Hong-Man; Liu, He-Qun; Nguyen, Truong Quang; Nguyen, Sang Ngoc; Duong, Tang Van; Eto, Koshiro; Nishikawa, Kanto; Matsui, Masafumi; Orlov, Nikolai L; Stuart, Bryan L; Brown, Rafe M; Rowley, Jodi J L; Murphy, Robert W; Wang, Ying-Yong; Che, Jing

    2018-07-01

    Southeast Asia and southern China (SEA-SC) harbor a highly diverse and endemic flora and fauna that is under increasing threat. An understanding of the biogeographical history and drivers of this diversity is lacking, especially in some of the most diverse and threatened groups. The Asian leaf-litter frog genus Leptolalax Dubois 1980 is a forest-dependent genus distributed throughout SEA-SC, making it an ideal study group to examine specific biogeographic hypotheses. In addition, the diversity of this genus remains poorly understood, and the phylogenetic relationships among species of Leptolalax and closely related Leptobrachella Smith 1928 remain unclear. Herein, we evaluate species-level diversity based on 48 of the 53 described species from throughout the distribution of Leptolalax. Molecular analyses reveal many undescribed species, mostly in southern China and Indochina. Our well-resolved phylogeny based on multiple nuclear DNA markers shows that Leptolalax is not monophyletic with respect to Leptobrachella and, thus, we assign the former to being a junior synonym of the latter. Similarly, analyses reject monophyly of the two subgenera of Leptolalax. The diversification pattern of the group is complex, involving a high degree of sympatry and prevalence of microendemic species. Northern Sundaland (Borneo) and eastern Indochina (Vietnam) appear to have played pivotal roles as geographical centers of diversification, and paleoclimatic changes and tectonic movements seem to have driven the major divergence of clades. Analyses fail to reject an "upstream" colonization hypothesis, and, thus, the genus appears to have originated in Sundaland and then colonized mainland Asia. Our results reveal that both vicariance and dispersal are responsible for current distribution patterns in the genus. Copyright © 2018 Elsevier Inc. All rights reserved.

  9. Abundance and survival rates of three leaf-litter frog species in fragments and continuous forest of the Mata Atlântica, Brazil

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    Henning Steinicke

    2018-04-01

    Full Text Available Habitat destruction and fragmentation alter the quality of habitats and put populations under the risk of extinction. Changes in population parameters can provide early warning signs of negative impacts. In tropical forests, where habitat loss and fragmentation are vast, such indicators are of high relevance for directing conservation efforts before effects are irreversible. Most of our knowledge from tropical ecosystems originates from community level surveys, whereas our understanding of the influence of habitat conversion on vital rates of species is limited. This study focused on the influence of anthropogenic habitat fragmentation on the survival probability and abundance of three leaf-litter frog species (Rhinella ornata, Ischnocnema guentheri and I. parva in forest patches of the Atlantic rainforest of South-east Brazil compared to a continuous forest. The species differ in their matrix tolerance: high for R. ornata and low for I. guentheri and I. parva and, thus, we examined whether their survival and abundance correspond to this classification. Ischnocnema guentheri showed highest abundances in all study sites and low mortality in the forest patches compared to the continuous forest; I. parva was encountered only in isolated fragments, with very low mortality in one isolated fragment; and the matrix tolerant species had generally low abundance and showed no clear pattern in terms of mortality in the different sites. Our counter-intuitive results show that even matrix sensitive amphibian species may show high abundance and low mortality in small forest patches. Therefore, these patches can be of high value for amphibian conservation regardless of their degree of matrix aversion. Landscape level conservation planning should not abandon small habitat patches, especially in highly fragmented tropical environments.

  10. Molecular systematics and phylogeography of Amazonian poison frogs of the genus Dendrobates.

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    Symula, R; Schulte, R; Summers, K

    2003-03-01

    The study of Amazonian biodiversity requires detailed knowledge of the phylogenetic relationships of closely related taxa distributed across Amazonia. The Amazonian poison frogs of the genus Dendrobates have undergone many taxonomic revisions, but the phylogenetic relationships within this group remain poorly understood. Most previous classifications were based on morphology and skin toxin analyses, with limited use of DNA sequence data. Using mtDNA sequence data from four gene regions (cytochrome b, cytochrome oxidase I, 16S rRNA, and 12S rRNA), we present a molecular phylogenetic analysis of the evolutionary relationships within a representative group of Amazonian Dendrobates. We use the resulting phylogenetic hypothesis to investigate different biogeographic hypotheses concerning genetic divergence and species diversity in Amazonia. The results of the analysis support the presence of ancient paleogeographic barriers to gene flow between eastern and western Amazonia, and indicate substantial genetic divergence between species found in the northern and southern regions of western Amazonia. Copyright 2002 Elsevier Science (USA)

  11. Co-occurrence patterns of common and rare leaf-litter frogs, epiphytic ferns and dung beetles across a gradient of human disturbance.

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    Johan A Oldekop

    Full Text Available Indicator taxa are commonly used to identify priority areas for conservation or to measure biological responses to environmental change. Despite their widespread use, there is no general consensus about the ability of indicator taxa to predict wider trends in biodiversity. Many studies have focused on large-scale patterns of species co-occurrence to identify areas of high biodiversity, threat or endemism, but there is much less information about patterns of species co-occurrence at local scales. In this study, we assess fine-scale co-occurrence patterns of three indicator taxa (epiphytic ferns, leaf litter frogs and dung beetles across a remotely sensed gradient of human disturbance in the Ecuadorian Amazon. We measure the relative contribution of rare and common species to patterns of total richness in each taxon and determine the ability of common and rare species to act as surrogate measures of human disturbance and each other. We find that the species richness of indicator taxa changed across the human disturbance gradient but that the response differed among taxa, and between rare and common species. Although we find several patterns of co-occurrence, these patterns differed between common and rare species. Despite showing complex patterns of species co-occurrence, our results suggest that species or taxa can act as reliable indicators of each other but that this relationship must be established and not assumed.

  12. Space use of Amazonian poison frogs: Testing the reproductive resource defense hypothesis

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    Poelman, E.H.; Dicke, M.

    2008-01-01

    In most Anuran species, space use includes a lek mating system with defense of a calling site for only a short time period during an individual's lifespan. In contrast, territoriality over a longer time period by one or both of the sexes has been reported in all studied dendrobatid frogs. In most

  13. Schellackia (Apicomplexa: Eimeriidae of the brazilian tree-frog, Phrynohyas venulosa (Amphibia: Anura from Amazonian Brazil

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    I. Paperna

    1995-10-01

    Full Text Available Endogenous stages of a Schellackia species are described in histological sections of the intestine of the tree-frog, Phrynohyas venulosa, from North Brazil. Most oocysts sporulate within the epithelial cells of the gut, but a few were detected in the lamina propria.

  14. The effects of cannibalism on Amazonian poison frog egg and tadpole deposition and survivorship in Heliconia axil pools.

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    Summers, Kyle

    1999-06-01

    This study investigated the influence of cannibalism on egg and larval mortality, and on the deposition strategies of adults, in a tropical anuran breeding in very small leaf axil pools. Patterns of egg and tadpole deposition and mortality in the Amazonian poison frog, Dendrobates ventrimaculatus, were monitored in rainforest near Pompeya in Sucumbios Province, Ecuador. Oviposition and tadpole deposition typically ocurred in leaf axils of Heliconia plants. Pools typically received more than one oviposition. Egg survivorship was low, and significantly lower when eggs were deposited in pools with large tadpoles, indicating that cannibalism is an important source of mortality. Tadpole survivorship was also associated with the presence of other tadpoles: most pools ended with only one surviving tadpole, regardless of the number of tadpoles deposited in the pool. Egg deposition was signifcantly less likely for pools that had a tadpole in them, suggesting that adults can detect the presence of tadpoles and avoid ovipositing in pools that contain them. This hypothesis was tested with a series of pool choice experiments, which revealed that D. ventrimaculatus avoid placing either eggs or tadpoles into a pool which contains a large tadpole. Several hypotheses which could explain multiple deposition in this species are discussed.

  15. A new species of Amazonian snouted treefrog (Hylidae: Scinax) with description of a novel species-habitat association for an aquatic breeding frog

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    de Fraga, Rafael; Moravec, Jiří; Kaefer, Igor L.; Lima, Albertina P.

    2018-01-01

    The genus Scinax is one of the most specious genera of treefrogs of the family Hylidae. Despite the high number of potential new species of Scinax revealed in recent studies, the rate of species descriptions for Amazonia has been low in the last decade. A potential cause of this low rate may be the existence of morphologically cryptic species. Describing new species may not only impact the taxonomy and systematics of a group of organisms but also benefit other fields of biology. Ecological studies conducted in megadiverse regions, such as Amazonia, often meet challenging questions concerning insufficient knowledge of organismal alpha taxonomy. Due to that, detecting species-habitat associations is dependent on our ability to properly identify species. In this study, we first provide a description of a new species (including its tadpoles) of the genus Scinax distributed along heterogeneous landscapes in southern Amazonia; and secondly assess the influence of environmental heterogeneity on the new species’ abundance and distribution. Scinax ruberoculatus sp. nov. differs from all nominal congeners by its small size (SVL 22.6–25.9 mm in males and 25.4–27.5 mm in females), by having a dark brown spot on the head and scapular region shaped mainly like the moth Copiopteryx semiramis (or a human molar in lateral view, or a triangle), bicolored reddish and grey iris, snout truncate in dorsal view, bilobate vocal sac in males, by its advertisement call consisting of a single pulsed note with duration of 0.134–0.331 s, 10–23 pulses per note, and dominant frequency 1,809–1,895 Hz. Both occurrence and abundance of the new species are significantly influenced by silt content in the soil. This finding brings the first evidence that edaphic factors influence species-habitat association in Amazonian aquatic breeding frogs. PMID:29441233

  16. Dietary source for skin alkaloids of poison frogs (Dendrobatidae)?

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    Daly, J W; Martin Garraffo, H; Spande, T F; Jaramillo, C; Stanley Rand, A

    1994-04-01

    A wide range of alkaloids, many of which are unknown elsewhere in nature, occur in skin of frogs. Major classes of such alkaloids in dendrobatid frogs are the batrachotoxins, pumiliotoxins, histrionicotoxins, gephyrotoxins, and decahydroquinolines. Such alkaloids are absent in skin of frogs (Dendrobates auratus) raised in Panama on wingless fruit flies in indoor terraria. Raised on leaf-litter arthropods that were collected in a mainland site, such terraria-raised frogs contain tricyclic alkaloids including the beetle alkaloid precoccinelline, 1,4-disubstituted quinolizidines, pyrrolizidine oximes, the millipede alkaloid nitropolyzonamine, a decahydroquinoline, a gephyrotoxin, and histrionicotoxins. The profiles of these alkaloids in the captive-raised frogs are closer to the mainland population ofDendrobates auratus at the leaf-litter site than to the parent population ofDendrobates auratus from a nearby island site. Extracts of a seven-month sampling of leaf-litter insects contained precoccinelline, pyrrolizidine oxime236 (major), and nitropolyzonamine (238). The results indicate a dietary origin for at least some "dendrobatid alkaloids," in particular the pyrrolizidine oximes, the tricyclic coccinellines, and perhaps the histrionicotoxins and gephyrotoxins.

  17. Psychrophrynella glauca sp. n., a new species of terrestrial-breeding frogs (Amphibia, Anura, Strabomantidae from the montane forests of the Amazonian Andes of Puno, Peru

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    Alessandro Catenazzi

    2018-02-01

    Full Text Available We describe a new species of small strabomantid frog (genus Psychrophrynella from a humid montane forest in the Peruvian Department of Puno. Specimens were collected at 2,225 m a.s.l. in the leaf litter of primary montane forest near Thiuni, along the Macusani–San Gabán road, in the province of Carabaya. The new species is assigned to Psychrophrynella on the basis of morphological similarity, including presence of a tubercle on the inner edge of the tarsus, and call composed of multiple notes. We also include genetic distances for 16S rRNA partial sequences between the new species and other strabomantid frogs. The species with lowest genetic distances are Psychrophrynella chirihampatu and Psychrophrynella usurpator. Psychrophrynella glauca sp. n. is readily distinguished from the three other species of Psychrophrynella (Psychrophrynella bagrecito, P. chirihampatu, and P. usurpator by its small size, and by having belly and ventral surfaces of legs reddish-brown or red, and chest and throat brown to dark brown with a profusion of bluish-gray flecks. The new species is only known from its type locality. With the discovery of P. glauca, the geographic distribution of Psychrophrynella is extended to the Department of Puno, where it was no longer represented after the description of the genus Microkayla. Furthermore, the Cordillera de Carabaya is the only mountain range known to be home to four of the seven genera of Holoadeninae (Bryophryne, Microkayla, Noblella, and Psychrophrynella, suggesting an intriguing evolutionary history for this group in southern Peru.

  18. Rate of Decomposition of Leaflitter in an Age Series Gmelina ...

    African Journals Online (AJOL)

    The study was carried out to investigate the rate of decomposition of Gmelina arborea Robx leaflitter in an age series in Gmelina plantation in shasa forest reserve in a Nigerian low land Forest. Rate of decomposition of Gmelina leaf litter was determined using litter bag technique and mass balance analysis to quantify the ...

  19. Leaf-litter breakdown in urban streams of Central Amazonia: direct and indirect effects of physical, chemical, and biological factors

    OpenAIRE

    Renato Tavares Martins; Adriano Sanches Melo; José Francisco Gonçalves-Jr; Neusa Hamada

    2015-01-01

    Urbanization alters water physical and chemical variables and may affect leaf-litter breakdown in streams. Higher temperature and nutrient inputs in urban streams can stimulate microbial biomass, which can increase leaf-litter breakdown rates over rates in nonurban streams. On the other hand, urbanization can reduce leaf-litter breakdown rates by eliminating shredders. We evaluated physical, chemical, and biological factors that may directly and indirectly affect leaf-litter breakdown of Cous...

  20. Breeding Guild Determines Frog Distributions in Response to Edge Effects and Habitat Conversion in the Brazil's Atlantic Forest.

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    Rodrigo B Ferreira

    Full Text Available Understanding the response of species with differing life-history traits to habitat edges and habitat conversion helps predict their likelihood of persistence across changing landscape. In Brazil's Atlantic Forest, we evaluated frog richness and abundance by breeding guild at four distances from the edge of a reserve: i 200 m inside the forest, ii 50 m inside the forest, iii at the forest edge, and iv 50 m inside three different converted habitats (coffee plantation, non-native Eucalyptus plantation, and abandoned pastures, hereafter matrix types. By sampling a dry and a wet season, we recorded 622 individual frogs representing 29 species, of which three were undescribed. Breeding guild (i.e. bromeliad, leaf-litter, and water-body breeders was the most important variable explaining frog distributions in relation to edge effects and matrix types. Leaf-litter and bromeliad breeders decreased in richness and abundance from the forest interior toward the matrix habitats. Water-body breeders increased in richness toward the matrix and remained relatively stable in abundance across distances. Number of large trees (i.e. DBH > 15 cm and bromeliads best explained frog richness and abundance across distances. Twenty species found in the interior of the forest were not found in any matrix habitat. Richness and abundance across breeding guilds were higher in the rainy season but frog distributions were similar across the four distances in the two seasons. Across matrix types, leaf-litter species primarily used Eucalyptus plantations, whereas water-body species primarily used coffee plantations. Bromeliad breeders were not found inside any matrix habitat. Our study highlights the importance of primary forest for bromeliad and leaf-litter breeders. We propose that water-body breeders use edge and matrix habitats to reach breeding habitats along the valleys. Including life-history characteristics, such as breeding guild, can improve predictions of frog

  1. Breeding Guild Determines Frog Distributions in Response to Edge Effects and Habitat Conversion in the Brazil's Atlantic Forest.

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    Ferreira, Rodrigo B; Beard, Karen H; Crump, Martha L

    2016-01-01

    Understanding the response of species with differing life-history traits to habitat edges and habitat conversion helps predict their likelihood of persistence across changing landscape. In Brazil's Atlantic Forest, we evaluated frog richness and abundance by breeding guild at four distances from the edge of a reserve: i) 200 m inside the forest, ii) 50 m inside the forest, iii) at the forest edge, and iv) 50 m inside three different converted habitats (coffee plantation, non-native Eucalyptus plantation, and abandoned pastures, hereafter matrix types). By sampling a dry and a wet season, we recorded 622 individual frogs representing 29 species, of which three were undescribed. Breeding guild (i.e. bromeliad, leaf-litter, and water-body breeders) was the most important variable explaining frog distributions in relation to edge effects and matrix types. Leaf-litter and bromeliad breeders decreased in richness and abundance from the forest interior toward the matrix habitats. Water-body breeders increased in richness toward the matrix and remained relatively stable in abundance across distances. Number of large trees (i.e. DBH > 15 cm) and bromeliads best explained frog richness and abundance across distances. Twenty species found in the interior of the forest were not found in any matrix habitat. Richness and abundance across breeding guilds were higher in the rainy season but frog distributions were similar across the four distances in the two seasons. Across matrix types, leaf-litter species primarily used Eucalyptus plantations, whereas water-body species primarily used coffee plantations. Bromeliad breeders were not found inside any matrix habitat. Our study highlights the importance of primary forest for bromeliad and leaf-litter breeders. We propose that water-body breeders use edge and matrix habitats to reach breeding habitats along the valleys. Including life-history characteristics, such as breeding guild, can improve predictions of frog distributions in

  2. The leaf-litter earthworm fauna (Annelida: Oligochaeta) of forests in ...

    African Journals Online (AJOL)

    A qualitative survey of the leaf-litter earthworm fauna of 11 selected indigenous forests in Limpopo Province, South Africa, was conducted to identify the species present, to describe the communities and to assess the relationship between indigenous and exotic species. A total of 8185 individuals from 17 species (five ...

  3. FROGS report

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    FROGS Reports present information on current research relevant to felsic magmatism, including commentaries on problems of current interest. Please contact Calvin Miller, Geology, 6028B, Vanderbilt University, Nashville, TN 37235; tel. 615-322-2986 about your own research, conferences, and ideas for stimulating commentaries.

  4. The impact of coffee and pasture agriculture on predatory and omnivorous leaf-litter ants.

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    Dias, Nivia da Silva; Zanetti, Ronald; Santos, Mônica Silva; Peñaflor, Maria Fernanda Gomes Villalba; Broglio, Sônia Maria Forti; Delabie, Jacques Hubert Charles

    2013-01-01

    Ants are known to function as reliable biological indicators for habitat impact assessment. They play a wide range of ecological roles depending on their feeding and nesting habits. By clustering ants in guilds, it is possible both to assess how agriculture and forest fragmentation can disturb ant communities and to predict the ecological impacts due to losses of a specific guild. This study aimed at determining the impact of non-shaded coffee and pasture agriculture on predatory and omnivorous guilds of leaf-litter ants of Atlantic Forest fragments in Minas Gerais, Brazil. Both coffee and pasture agriculture influenced leaf-litter ant community, although coffee was more disruptive than pasture. Coffee agriculture not only disturbed the diversity of predatory ants, but also negatively affected the number of predatory and omnivorous ants when compared to forest fragments. In contrast, pasture agriculture only disrupted the abundance of predatory ants. Fragment edges skirting crops were negatively affected in terms of leaf-litter ant abundance, but not diversity. Cluster analysis showed that forest fragments were similar irrespective of the cultivation, but the borders were similar to the crop. The study assessed agriculture impact by surveying ant guilds, and revealed that the predatory guild is more susceptible than omnivorous ants.

  5. Ecosystem-Wide Morphological Structure of Leaf-Litter Ant Communities along a Tropical Latitudinal Gradient

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    Silva, Rogério R.; Brandão, Carlos Roberto F.

    2014-01-01

    General principles that shape community structure can be described based on a functional trait approach grounded on predictive models; increased attention has been paid to factors accounting for the functional diversity of species assemblages and its association with species richness along environmental gradients. We analyze here the interaction between leaf-litter ant species richness, the local communities' morphological structure and fundamental niche within the context of a northeast-southeast latitudinal gradient in one of the world's most species-rich ecosystems, the Atlantic Forest, representing 2,700 km of tropical rainforest along almost 20o of latitude in eastern Brazil. Our results are consistent with an ecosystem-wide pattern in communities' structure, with relatively high species turnover but functionally analogous leaf-litter ant communities' organization. Our results suggest directional shifts in the morphological space along the environmental gradient from overdispersed to aggregated (from North to South), suggesting that primary productivity and environmental heterogeneity (altitude, temperature and precipitation in the case) determine the distribution of traits and regulate the assembly rules, shaping local leaf-litter ant communities. Contrary to the expected and most common pattern along latitudinal gradients, the Atlantic Forest leaf litter ant communities show an inverse pattern in richness, that is, richer communities in higher than in lower latitudes. The morphological specialization of communities showed more morphologically distinct communities at low latitudes and species redundancy at high latitudes. We claim that an inverse latitudinal gradient in primary productivity and environmental heterogeneity across the Atlantic forest may affect morphological diversity and species richness, enhancing species coexistence mechanisms, and producing thus the observed patterns. We suggest that a functional framework based on flexible enough traits

  6. Ecosystem-wide morphological structure of leaf-litter ant communities along a tropical latitudinal gradient.

    Science.gov (United States)

    Silva, Rogério R; Brandão, Carlos Roberto F

    2014-01-01

    General principles that shape community structure can be described based on a functional trait approach grounded on predictive models; increased attention has been paid to factors accounting for the functional diversity of species assemblages and its association with species richness along environmental gradients. We analyze here the interaction between leaf-litter ant species richness, the local communities' morphological structure and fundamental niche within the context of a northeast-southeast latitudinal gradient in one of the world's most species-rich ecosystems, the Atlantic Forest, representing 2,700 km of tropical rainforest along almost 20° of latitude in eastern Brazil. Our results are consistent with an ecosystem-wide pattern in communities' structure, with relatively high species turnover but functionally analogous leaf-litter ant communities' organization. Our results suggest directional shifts in the morphological space along the environmental gradient from overdispersed to aggregated (from North to South), suggesting that primary productivity and environmental heterogeneity (altitude, temperature and precipitation in the case) determine the distribution of traits and regulate the assembly rules, shaping local leaf-litter ant communities. Contrary to the expected and most common pattern along latitudinal gradients, the Atlantic Forest leaf litter ant communities show an inverse pattern in richness, that is, richer communities in higher than in lower latitudes. The morphological specialization of communities showed more morphologically distinct communities at low latitudes and species redundancy at high latitudes. We claim that an inverse latitudinal gradient in primary productivity and environmental heterogeneity across the Atlantic forest may affect morphological diversity and species richness, enhancing species coexistence mechanisms, and producing thus the observed patterns. We suggest that a functional framework based on flexible enough traits

  7. Ecosystem-wide morphological structure of leaf-litter ant communities along a tropical latitudinal gradient.

    Directory of Open Access Journals (Sweden)

    Rogério R Silva

    Full Text Available General principles that shape community structure can be described based on a functional trait approach grounded on predictive models; increased attention has been paid to factors accounting for the functional diversity of species assemblages and its association with species richness along environmental gradients. We analyze here the interaction between leaf-litter ant species richness, the local communities' morphological structure and fundamental niche within the context of a northeast-southeast latitudinal gradient in one of the world's most species-rich ecosystems, the Atlantic Forest, representing 2,700 km of tropical rainforest along almost 20° of latitude in eastern Brazil. Our results are consistent with an ecosystem-wide pattern in communities' structure, with relatively high species turnover but functionally analogous leaf-litter ant communities' organization. Our results suggest directional shifts in the morphological space along the environmental gradient from overdispersed to aggregated (from North to South, suggesting that primary productivity and environmental heterogeneity (altitude, temperature and precipitation in the case determine the distribution of traits and regulate the assembly rules, shaping local leaf-litter ant communities. Contrary to the expected and most common pattern along latitudinal gradients, the Atlantic Forest leaf litter ant communities show an inverse pattern in richness, that is, richer communities in higher than in lower latitudes. The morphological specialization of communities showed more morphologically distinct communities at low latitudes and species redundancy at high latitudes. We claim that an inverse latitudinal gradient in primary productivity and environmental heterogeneity across the Atlantic forest may affect morphological diversity and species richness, enhancing species coexistence mechanisms, and producing thus the observed patterns. We suggest that a functional framework based on

  8. Frog eat frog: exploring variables influencing anurophagy

    Directory of Open Access Journals (Sweden)

    G. John Measey

    2015-08-01

    Full Text Available Background. Frogs are generalist predators of a wide range of typically small prey items. But descriptions of dietary items regularly include other anurans, such that frogs are considered to be among the most important of anuran predators. However, the only existing hypothesis for the inclusion of anurans in the diet of post-metamorphic frogs postulates that it happens more often in bigger frogs. Moreover, this hypothesis has yet to be tested.Methods. We reviewed the literature on frog diet in order to test the size hypothesis and determine whether there are other putative explanations for anurans in the diet of post-metamorphic frogs. In addition to size, we recorded the habitat, the number of other sympatric anuran species, and whether or not the population was invasive. We controlled for taxonomic bias by including the superfamily in our analysis.Results. Around one fifth of the 355 records included anurans as dietary items of populations studied, suggesting that frogs eating anurans is not unusual. Our data showed a clear taxonomic bias with ranids and pipids having a higher proportion of anuran prey than other superfamilies. Accounting for this taxonomic bias, we found that size in addition to being invasive, local anuran diversity, and habitat produced a model that best fitted our data. Large invasive frogs that live in forests with high anuran diversity are most likely to have a higher proportion of anurans in their diet.Conclusions. We confirm the validity of the size hypothesis for anurophagy, but show that there are additional significant variables. The circumstances under which frogs eat frogs are likely to be complex, but our data may help to alert conservationists to the possible dangers of invading frogs entering areas with threatened anuran species.

  9. Neotropical woodlice (isopoda colonizing leaf-litter of pioneer plants in a coal residue disposal environment

    Directory of Open Access Journals (Sweden)

    Luciana Regina Podgaiski

    2011-06-01

    Full Text Available The irregular disposal of coal combustion residues has adverse impacts on terrestrial ecosystems. Pioneer plants and soil invertebrates play an important role in the recovery of these areas. The goal of this study was to investigate the colonization patterns of terrestrial isopods (Oniscidea in leaf litter of three spontaneous pioneer plants (grass - Poaceae, shrub - Euphorbiaceae, tree - Anarcadiaceae at sites used for fly ash or boiler slag disposal. The experiment consisted of eight blocks (four per disposal site of 12 litter bags each (four per plant species that were randomly removed after 6, 35, 70 or 140 days of field exposure. Three isopod species were found in the litter bags: Atlantoscia floridana (van Name, 1940 (Philosciidae; n = 116, Benthana taeniata Araujo & Buckup, 1994 (Philosciidae; n = 817 and Balloniscus sellowii (Brandt, 1833 (Balloniscidae; n = 48. The isopods colonized the three leaf-litter species equally during the exposure period. However, the pattern of leaf-litter colonization by these species suggests a conflict of objectives between high quality food and shelter availability. The occurrence of A. floridana and the abundance and fecundity of B. taeniata were influenced by the residue type, indicating that the isopods have different degrees of tolerance to the characteristics of the studied sites. Considering that terrestrial isopods are abundant detritivores and stimulate the humus-forming processes, it is suggested that they could have an indirect influence on the soil restoration of this area.

  10. Tactical reproductive parasitism via larval cannibalism in Peruvian poison frogs.

    Science.gov (United States)

    Brown, Jason L; Morales, Victor; Summers, Kyle

    2009-04-23

    We report an unusual example of reproductive parasitism in amphibians. Dendrobates variabilis, an Amazonian poison frog, oviposits at the surface of the water in small pools in plants and deposits tadpoles within the pools. Tadpoles are highly cannibalistic and consume young tadpoles if they are accessible. Deposition of embryos and tadpoles in the same pool is common. Genetic analyses indicate that tadpoles are frequently unrelated to embryos in the same pool. A pool choice experiment in the field demonstrated that males carrying tadpoles prefer to place them in pools with embryos, facilitating reproductive parasitism via cannibalism.

  11. Dynamics of cesium-134 and biomass in treated and untreated turkey oak leaf-litter bags

    International Nuclear Information System (INIS)

    Croom, J.M.; Ragsdale, H.L.

    1978-01-01

    Litter bags were prepared from leaves harvested in late fall from turkey oak trees (Quercus laevis) tagged with 134 Cs. Untreated bags and bags treated by soaking in 1000 ppM HgCl 2 were placed in the field on Dec. 7, 1974. Five bags of each treatment were retrieved at 7-, 14-, and 30-day intervals as the experiment progressed. Treated bags remained free of visible fungal hyphae growth for 12 weeks. Untreated bags had lost more weight but less 134 Cs than treated bags after 14 and 56 days, respectively. After 9 months, untreated bags had lost 33% weight and 90% 134 Cs. Although 134 Cs is rapidly leached from litter (ecological half-life approximately equal to 12 weeks), some is retained by fungal hyphae on leaf-litter surfaces. This mechanism of mineral retention in the litter layer could represent adaptation at the ecosystem level for nutrient conservation

  12. Bioactive alkaloids of frog skin: combinatorial bioprospecting reveals that pumiliotoxins have an arthropod source.

    Science.gov (United States)

    Daly, John W; Kaneko, Tetsuo; Wilham, Jason; Garraffo, H Martin; Spande, Thomas F; Espinosa, Alex; Donnelly, Maureen A

    2002-10-29

    Nearly 500 alkaloids have been detected in skin extracts from frogs of the family Dendrobatidae. All seem to have been sequestered unchanged into skin glands from alkaloid-containing arthropods. Ants, beetles, and millipedes seem to be the source of decahydroquinolines, certain izidines, coccinellines, and spiropyrrolizidine oximes. But the dietary source for a major group of frog-skin alkaloids, namely the pumiliotoxins (PTXs), alloPTXs, and homoPTXs, remained a mystery. In hopes of revealing an arthropod source for the PTX group, small arthropods were collected from eight different sites on a Panamanian island, where the dendrobatid frog (Dendrobates pumilio) was known to contain high levels of two PTXs. The mixed arthropod collections from several sites, each representing up to 20 arthropod taxa, contained PTX 307A and/or alloPTX 323B. In addition, the mixed arthropod collections from several sites contained a 5,8-disubstituted indolizidine (205A or 235B), representing another class of alkaloids previously unknown from an arthropod. An ant alkaloid, decahydroquinoline 195A, was detected in the mixed arthropod collections from several sites. Thus, "combinatorial bioprospecting" demonstrates that further collection and analysis of individual taxa of leaf-litter arthropods should reveal the taxa from which PTXs, alloPTXs, and 5,8-disubstituted indolizidines are derived.

  13. Yet More Frogs

    Science.gov (United States)

    Shutler, Paul M. E.

    2011-01-01

    Extending a recent paper by Derek Holton, we show how to represent the algorithm for the Frog Problem diagrammatically. This diagrammatic representation suggests a simpler proof of the symmetrical case (equal numbers of frogs of each colour) by allowing the even and odd cases to be treated together. It also provides a proof in the asymmetrical…

  14. Courtship in Frogs

    Indian Academy of Sciences (India)

    Vertebrate vocalization came into existence for the first time in frogs. Acoustic signals produced by the frogs have well-defined physical characteristics and a clear biological meaning. The signals are meant to attract and assess the sex, species identity and genetic quality of potential mates. Acoustic communication plays a ...

  15. Wildfires in bamboo-dominated Amazonian forest: impacts on above-ground biomass and biodiversity.

    Directory of Open Access Journals (Sweden)

    Jos Barlow

    Full Text Available Fire has become an increasingly important disturbance event in south-western Amazonia. We conducted the first assessment of the ecological impacts of these wildfires in 2008, sampling forest structure and biodiversity along twelve 500 m transects in the Chico Mendes Extractive Reserve, Acre, Brazil. Six transects were placed in unburned forests and six were in forests that burned during a series of forest fires that occurred from August to October 2005. Normalized Burn Ratio (NBR calculations, based on Landsat reflectance data, indicate that all transects were similar prior to the fires. We sampled understorey and canopy vegetation, birds using both mist nets and point counts, coprophagous dung beetles and the leaf-litter ant fauna. Fire had limited influence upon either faunal or floral species richness or community structure responses, and stems <10 cm DBH were the only group to show highly significant (p = 0.001 community turnover in burned forests. Mean aboveground live biomass was statistically indistinguishable in the unburned and burned plots, although there was a significant increase in the total abundance of dead stems in burned plots. Comparisons with previous studies suggest that wildfires had much less effect upon forest structure and biodiversity in these south-western Amazonian forests than in central and eastern Amazonia, where most fire research has been undertaken to date. We discuss potential reasons for the apparent greater resilience of our study plots to wildfire, examining the role of fire intensity, bamboo dominance, background rates of disturbance, landscape and soil conditions.

  16. Wildfires in bamboo-dominated Amazonian forest: impacts on above-ground biomass and biodiversity.

    Science.gov (United States)

    Barlow, Jos; Silveira, Juliana M; Mestre, Luiz A M; Andrade, Rafael B; Camacho D'Andrea, Gabriela; Louzada, Julio; Vaz-de-Mello, Fernando Z; Numata, Izaya; Lacau, Sébastien; Cochrane, Mark A

    2012-01-01

    Fire has become an increasingly important disturbance event in south-western Amazonia. We conducted the first assessment of the ecological impacts of these wildfires in 2008, sampling forest structure and biodiversity along twelve 500 m transects in the Chico Mendes Extractive Reserve, Acre, Brazil. Six transects were placed in unburned forests and six were in forests that burned during a series of forest fires that occurred from August to October 2005. Normalized Burn Ratio (NBR) calculations, based on Landsat reflectance data, indicate that all transects were similar prior to the fires. We sampled understorey and canopy vegetation, birds using both mist nets and point counts, coprophagous dung beetles and the leaf-litter ant fauna. Fire had limited influence upon either faunal or floral species richness or community structure responses, and stems wildfires had much less effect upon forest structure and biodiversity in these south-western Amazonian forests than in central and eastern Amazonia, where most fire research has been undertaken to date. We discuss potential reasons for the apparent greater resilience of our study plots to wildfire, examining the role of fire intensity, bamboo dominance, background rates of disturbance, landscape and soil conditions.

  17. How People Domesticated Amazonian Forests

    Directory of Open Access Journals (Sweden)

    Carolina Levis

    2018-01-01

    Full Text Available For millennia, Amazonian peoples have managed forest resources, modifying the natural environment in subtle and persistent ways. Legacies of past human occupation are striking near archaeological sites, yet we still lack a clear picture of how human management practices resulted in the domestication of Amazonian forests. The general view is that domesticated forests are recognizable by the presence of forest patches dominated by one or a few useful species favored by long-term human activities. Here, we used three complementary approaches to understand the long-term domestication of Amazonian forests. First, we compiled information from the literature about how indigenous and traditional Amazonian peoples manage forest resources to promote useful plant species that are mainly used as food resources. Then, we developed an interdisciplinary conceptual model of how interactions between these management practices across space and time may form domesticated forests. Finally, we collected field data from 30 contemporary villages located on and near archaeological sites, along four major Amazonian rivers, to compare with the management practices synthesized in our conceptual model. We identified eight distinct categories of management practices that contribute to form forest patches of useful plants: (1 removal of non-useful plants, (2 protection of useful plants, (3 attraction of non-human animal dispersers, (4 transportation of useful plants, (5 selection of phenotypes, (6 fire management, (7 planting of useful plants, and (8 soil improvement. Our conceptual model, when ethnographically projected into the past, reveals how the interaction of these multiple management practices interferes with natural ecological processes, resulting in the domestication of Amazonian forest patches dominated by useful species. Our model suggests that management practices became more frequent as human population increased during the Holocene. In the field, we found that

  18. Courtship in Frogs

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 12. Courtship in Frogs Role of Acoustic Communication in Amphibian Courtship Behaviour. Debjani Roy. General Article Volume 1 Issue 12 December 1996 pp 39-48 ...

  19. Differences in water depth determine leaf-litter decomposition in streams: implications on impact assessment reliability

    Directory of Open Access Journals (Sweden)

    Martínez A.

    2016-01-01

    Full Text Available Leaf-litter decomposition is a widespread functional indicator to assess the stream ecosystem status. However, the spatial location of leaf-bags could distort the impact assessment since intrinsic features of a given site have an important role in the spatial distribution of macroinvertebrates, which could affect decomposition rate. A source of variability that can be easily controlled is the water depth at which bags are incubated in stream bed. Therefore, we tested if water depth within a same mesohabitat (riffles can determine decomposition rates. Due to the seasonal variability of macroinvertebrate assemblages in temperate regions, the study was performed in autumn-winter and spring to test the consistency of the findings. In three streams from North of Spain 15 mesh bags with alder leaves were placed in riffles covering a gradient of depths. Depth had a positive effect on decomposition rates and biomass of associated total invertebrates and shredders in autumn-winter, fauna variables helping to explain the differences in rates. In spring, depth affected negatively rates, the observed variability being weakly explained by invertebrates, which did not show differences along depth. Despite the opposite trend between seasons, water depth influences the decomposition rates, which may reduce or increase differences among systems if the water depth distribution is greatly biased. Our study highlights the importance of covering a similar range of water depths in the different systems being compared.

  20. [Relative abundance and microhabitat use by the frog Geobatrachus walkeri (Anura: Strabomantidae) in two habitats of Sierra Nevada de Santa Marta, Colombia].

    Science.gov (United States)

    Martínez Baños, Vera; Pacheco Florez, Vanesa; Ramírez-Pinilla, Martha P

    2011-06-01

    Geobatrachus walkeri belongs to a monotypic frog genus endemic to the San Lorenzo area, Sierra Nevada de Santa Marta, Colombia. This species has been categorized as endangered because of its small distribution area and the decline in the extent and quality of its habitat. It inhabits two forest types with different composition and structure, the native secondary forest and a pine plantation (dominated by Pinus patula). To compare the relative abundance and microhabitat use of this species in these habitat types, 30 quadrants/environment were distributed randomly. The individual number, microhabitat use and other aspects of its natural history were registered using visual encounter surveys in both sites, including non-sampled areas in the quadrants. The relative abundance of frogs was significantly different between habitats and among seasons. The highest abundance of G. walkeri relative to the total area was found in the pine plantation, being 2.3 times higher than in the natural forest. More frogs were significantly found during the rainy season; nevertheless, active individuals were also found during the dry season. Significant differences were found in the microhabitat use with respect to the forest type and season. The most frequently microhabitat used in the two forest types was the pine leaf-litter; besides, in the native forest, the microhabitat occupied more frequently presented medium and large size stones. Geobatrachus walkeri is a successful species in pine plantations, associated permanently to its leaf-litter environment where it seems to develop its entire life cycle. The clear modifications in the soils and water, derived from the introduction of the pine plantation in this area, seem not to have negatively affected the conservation and successful maintenance of this species.

  1. Leaf-litter leachate concentration promotes heterotrophy in freshwater biofilms: Understanding consequences of water scarcity.

    Science.gov (United States)

    Martínez, Aingeru; Kominoski, John Stephen; Larrañaga, Aitor

    2017-12-01

    Climate change is increasing overall temporal variability in precipitation resulting in a seasonal water availability, both increasing periods of flooding and water scarcity. During low water availability periods, the concentration of leachates from riparian vegetation increases, subsequently increasing dissolved organic matter (DOM). Moreover, shifts in riparian vegetation by land use changes impact the quantity and quality of DOM. Our objective was to test effects of increasing DOM concentrations from Eucalyptus grandis (one of the most cultivated tree species in the world) leachates on the metabolism (respiration, R; gross primary productivity, GPP) and extracellular enzyme activities (EEAs) of freshwater biofilms. To test effects of DOM concentrations on freshwater biofilm functions, we incubated commercial cellulose sponges in a freshwater pond to allow biofilm colonization, and then exposed biofilms to five different concentrations of leaf-litter leachates of E. grandis for five days. To test if responses to DOM concentrations varied with colonization stage of biofilms, we measured treatment effects on biofilms colonizing standard substrates after one, two, three and four weeks of colonization. Increases in leachates concentrations enhanced biofilm heterotrophy, increasing R rates and decreasing GPP. Leachate concentrations did not affect biofilm EEAs, and changes in biofilm metabolism were not explained by treatment-induced changes in biofilm biomass or stoichiometry. We detected the lowest production:respiration ratios, i.e. more heterotrophic assemblages, with the most concentrated leachate solution and the most advanced biofilm colonization stages. Shifts in quantity of dissolved organic matter in freshwaters may further influence ecosystem metabolism and carbon processing. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Leaf-litter inputs from an invasive nitrogen-fixing tree influence organic-matter dynamics and nitrogen inputs in a Hawaiian river

    Science.gov (United States)

    Richard A. MacKenzie; Tracy N. Wiegner; Frances Kinslow; Nicole Cormier; Ayron M. Strauch

    2013-01-01

    Abstract. We examined how invasion of tropical riparian forests by an exotic N-fixing tree (Falcataria moluccana) affects organic-matter dynamics in a Hawaiian river by comparing early stages of leaf-litter breakdown between the exotic F. moluccana and native Metrosideros polymorpha trees. We examined early...

  3. Tree species richness of upper Amazonian forests

    OpenAIRE

    Gentry, Alwyn H.

    1988-01-01

    Upper Amazonian data for tree species richness in 1-hectare plots are reported. All plants ≥10 cm diameter were censused and identified in six plots in Amazonian Peru and one on the Venezuela-Brazil border. The two plots from the everwet forests near Iquitos, Peru, are the most species-rich in the world, with ≈300 species ≥10 cm diameter in single hectares; all of the Peruvian plots are among the most species-rich ever reported. Contrary to accepted opinion, upper Amazonian forest, and perhap...

  4. Community Structure of Leaf-Litter Ants in a Neotropical Dry Forest: A Biogeographic Approach to Explain Betadiversity

    Directory of Open Access Journals (Sweden)

    Rogério Silvestre

    2012-01-01

    Full Text Available This paper describes habitat and geographic correlates of ant diversity in Serra da Bodoquena, a poorly surveyed region of central-western Brazil. We discuss leaf-litter ant diversity on a regional scale, with emphasis on the contribution of each of the processes that form the evolutionary basis of contemporary beta diversity. The diversity of leaf-litter ants was assessed from a series of 262 Winkler samples conducted in two microbasins within a deciduous forest domain. A total of 170 litter-dwelling ant species in 45 genera and 11 subfamilies was identified. The data showed that the study areas exhibited different arrangements of ant fauna, with a high turnover in species composition between sites, indicating high beta diversity. Our analysis suggests that the biogeographic history of this tropical dry forest in the centre of South America could explain ant assemblage structure more than competitive dominance. The co-occurrence analysis showed that species co-occur less often than expected by chance in only two of the localities, suggesting that, for most of the species, co-occurrences are random. The assessment of the structure of the diversity of litter-dwelling ants is the first step in understanding the beta diversity patterns in this region of great biogeographic importance.

  5. It's a Frog's Life

    Science.gov (United States)

    Coffey, Audrey L.; Sterling, Donna R.

    2003-01-01

    When a preschool teacher unexpectedly found tadpoles in the school's outdoor baby pool, she recognized an unusual opportunity for her students to study pond life up close. By following the tadpoles' development, students learned about frogs, life cycles, habitats. (Contains 1 resource.)

  6. Did true frogs 'dispersify'?

    Science.gov (United States)

    Chan, Kin Onn; Brown, Rafe M

    2017-08-01

    The interplay between range expansion and concomitant diversification is of fundamental interest to evolutionary biologists, particularly when linked to intercontinental dispersal and/or large scale extinctions. The evolutionary history of true frogs has been characterized by circumglobal range expansion. As a lineage that survived the Eocene-Oligocene extinction event (EOEE), the group provides an ideal system to test the prediction that range expansion triggers increased net diversification. We constructed the most densely sampled, time-calibrated phylogeny to date in order to: (i) characterize tempo and patterns of diversification; (ii) assess the impact of the EOEE; and (iii) test the hypothesis that range expansion was followed by increased net diversification. We show that late Eocene colonization of novel biogeographic regions was not affected by the EOEE and surprisingly, global expansion was not followed by increased net diversification. On the contrary, the diversification rate declined or did not shift following geographical expansion. Thus, the diversification history of true frogs contradicts the prevailing expectation that amphibian net diversification accelerated towards the present or increased following range expansion. Rather, our results demonstrate that despite their dynamic biogeographic history, true frogs diversified at a relatively constantly rate, even as they colonized the major land masses of Earth. © 2017 The Author(s).

  7. Immune function in Amazonian horticulturalists.

    Science.gov (United States)

    Blackwell, Aaron D; Trumble, Benjamin C; Maldonado Suarez, Ivan; Stieglitz, Jonathan; Beheim, Bret; Snodgrass, J Josh; Kaplan, Hillard; Gurven, Michael

    2016-07-01

    Amazonian populations are exposed to diverse parasites and pathogens, including protozoal, bacterial, fungal and helminthic infections. Yet much knowledge of the immune system is based on industrialised populations where these infections are relatively rare. This study examines distributions and age-related differences in 22 measures of immune function for Bolivian forager-horticulturalists and US and European populations. Subjects were 6338 Tsimane aged 0-90 years. Blood samples collected between 2004-2014 were analysed for 5-part blood differentials, C-reactive protein, erythrocyte sedimentation rate (ESR) and total immunoglobulins E, G, A and M. Flow cytometry was used to quantify naïve and non-naïve CD4 and CD8 T cells, natural killer cells, and B cells. Compared to reference populations, Tsimane have elevated levels of most immunological parameters, particularly immunoglobulins, eosinophils, ESR, B cells, and natural killer cells. However, monocytes and basophils are reduced and naïve CD4 cells depleted in older age groups. Tsimane ecology leads to lymphocyte repertoires and immunoglobulin profiles that differ from those observed in industrialised populations. These differences have consequences for disease susceptibility and co-vary with patterns of other life history traits, such as growth and reproduction.

  8. Litter mercury deposition in the Amazonian rainforest

    International Nuclear Information System (INIS)

    Fostier, Anne Hélène; Melendez-Perez, José Javier; Richter, Larissa

    2015-01-01

    The objective of this work was to assess the flux of atmospheric mercury transferred to the soil of the Amazonian rainforest by litterfall. Calculations were based on a large survey of published and unpublished data on litterfall and Hg concentrations in litterfall samples from the Amazonian region. Litterfall based on 65 sites located in the Amazon rainforest averaged 8.15 ± 2.25 Mg ha −1  y −1 . Average Hg concentrations were calculated from nine datasets for fresh tree leaves and ten datasets for litter, and a median concentration of 60.5 ng Hg g −1 was considered for Hg deposition in litterfall, which averaged 49 ± 14 μg m −2  yr −1 . This value was used to estimate that in the Amazonian rainforest, litterfall would be responsible for the annual removing of 268 ± 77 Mg of Hg, approximately 8% of the total atmospheric Hg deposition to land. The impact of the Amazon deforestation on the Hg biogeochemical cycle is also discussed. - Highlights: • Based on published data we estimated the litterfall in the Amazonian rainforest. • All the published data on Hg concentration in leaves and litter from the region and some unpublished data are presented. • We calculated the litter mercury deposition. • We estimated the contribution of dry, wet and litter Hg deposition in the Amazonian rainforest. • We also discussed the impact of Amazon deforestation on the Hg biogeochemical cycle. - The Amazonian rainforest is responsible for removing at least 268 Mg Hg y −1 , 8% of the total atmospheric mercury deposition to land.

  9. Lithobates sylvaticus (wood frog)

    Science.gov (United States)

    Fuller, Pam

    2016-01-01

    A single specimen found southwest of Hattiesburg in Timberton (31.270391oN, 89.327675oW; WGS 84). 23 July 2015. Gary, Kat, and Ron Lukens. Verifi ed by Kenneth Krysko, Florida Museum of Natural History (UF-Herpetology 176455). This species has never been recorded from the state of Mississippi before (Dodd 2013. Frogs of the United States and Canada – Volume 2. John Hopkins University Press, Baltimore, Maryland. 982 pp.). According to Dodd (2013), the closest population is located in east central Alabama, approximately 400 km to the northeast, as documented by Davis and Folkerts (1986. Brimleyana 12:29-50).

  10. Resilience of Amazonian landscapes to agricultural intensification

    NARCIS (Netherlands)

    Jakovac, C.C.

    2015-01-01

    ISBN: 978-94-6257-443-4 Author: Catarina C. Jakovac Title: Resilience of Amazonian landscapes to agricultural intensification Swidden cultivation is the traditional agricultural system in riverine Amazonia, which supports local livelihoods and

  11. A Comparison of V-Frog[C] to Physical Frog Dissection

    Science.gov (United States)

    Lalley, James P.; Piotrowski, Phillip S.; Battaglia, Barbara; Brophy, Keith; Chugh, Kevin

    2010-01-01

    The purpose of the present study was to examine and compare the effectiveness of virtual frog dissection using V-Frog[C] and physical frog dissection on learning, retention, and affect. Subjects were secondary students enrolled in year-long life science classes in a suburban high school (N=102). Virtual dissections were done with V-Frog[C], a…

  12. Pre-LBA Amazonian Region Micrometeorological Experiment (ARME) Data

    Data.gov (United States)

    National Aeronautics and Space Administration — The Amazonian Region Micrometeorological Experiment (ARME) data contain micrometeorological data (climate, interception of precipitation, mircometeorology and soil...

  13. 49 CFR 213.137 - Frogs.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Frogs. 213.137 Section 213.137 Transportation... TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.137 Frogs. (a) The flangeway depth measured from a plane across the wheel-bearing area of a frog on Class 1 track shall not be less than 13/8 inches, or...

  14. Amazonian foods and implications for human biology.

    Science.gov (United States)

    Dufour, Darna L; Piperata, Barbara A; Murrieta, Rui S S; Wilson, Warren M; Williams, Drake D

    2016-07-01

    Diets of subsistence-based Amazonian populations have been linked to local resources, but are changing with market penetration. To review the available data on traditional Amazonian foods and diets and evaluate their implications for human biology as a step toward understanding nutrition transitions in the region. This study used the Human Relations Area Files for information on the diets of Amerindian groups in the Amazon Basin from 1950 to the present, and used other published sources and the authors' own data. Data on food use was identified for only nine groups and dietary intake data for individuals in only three of the groups. A diet based on starchy staples (manioc and plantains) and fish, supplemented with a limited variety of other plant and animal foods, was found. Bitter manioc-based foods were associated with the consumption of cyanogens and fish with the consumption of mercury. Diets of adults appear to be adequate in energy and protein and low in fats. Children's diets were not well documented. Based on the limited available data, Amazonian diets are restricted in variety, but appear to be adequate in energy and protein for adults, but likely insufficiently nutrient-dense for children.

  15. Litter mercury deposition in the Amazonian rainforest.

    Science.gov (United States)

    Fostier, Anne Hélène; Melendez-Perez, José Javier; Richter, Larissa

    2015-11-01

    The objective of this work was to assess the flux of atmospheric mercury transferred to the soil of the Amazonian rainforest by litterfall. Calculations were based on a large survey of published and unpublished data on litterfall and Hg concentrations in litterfall samples from the Amazonian region. Litterfall based on 65 sites located in the Amazon rainforest averaged 8.15 ± 2.25 Mg ha(-1) y(-1). Average Hg concentrations were calculated from nine datasets for fresh tree leaves and ten datasets for litter, and a median concentration of 60.5 ng Hg g(-1) was considered for Hg deposition in litterfall, which averaged 49 ± 14 μg m(-2) yr(-1). This value was used to estimate that in the Amazonian rainforest, litterfall would be responsible for the annual removing of 268 ± 77 Mg of Hg, approximately 8% of the total atmospheric Hg deposition to land. The impact of the Amazon deforestation on the Hg biogeochemical cycle is also discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. River-Borne Sediment Exports, Sedimentation Rates, and Influence on Benthos and Leaflitter Breakdown in Southern Caribbean Mangroves (uraba, Colombia)

    Science.gov (United States)

    Blanco, J. F.; Taborda, A.; Arroyave, A.

    2011-12-01

    Deposition of river-borne sediments is a major issue in coastal ecosystems worldwide, but no study has been conducted in Neotropical mangroves. Mangroves in the Urabá Gulf (Southern Caribbean coast of Colombia) receive one of the highest sediment loads (crop district. Annual sedimentation rates were computed based in monthly samplings (2009-2010) in mangrove fringes across the Turbo River Delta using bottom-fixed 1L-cylinders (n=15). A significant spatial variation (0.04-0.9 ton m-2 yr-1) was observed among sampling stations within the delta, but the highest trapping occurred on river's main channel (2.54 ton m-2 yr-1). Temporal variation was smaller than spatial variation. Monitoring (twenty 1-m2 quadrats x 3 sites x 12 months) of a dominant mangrove-floor gastropod (Neritina virginea) observed a positive increase of density (4-125 ind. m-2: One-way ANOVA: p<0.001) along a sedimentation gradient (monthly means for low and high sedimentation sites: 3-69 kg m-2 yr-1). The role of N. virginea on leaflitter breakdown relative to sedimentation level was experimentally tested in a black mangrove (Avicennia germinans) stand by using 180 wire-mesh cages (15 x 15 x 25 cm) placed on the forest floor as experimental units, to prevent snail and crab access. After clearing existing snails and litter from the muddy bottom, each cage was placed and 1 senescent leaf of A. germinans and 7 snails were introduced (previously weighed) (snail abundance was similar to background densities). Three levels of area-weighed sedimentation rates (1, 3 and 18 g per cage) were daily added to test the impacts of the field-observed sedimentation gradient. The experiment was carried out during one month. Fresh leaf mass was different among treatments during the first week, increasing in proportion to the sedimentation rate probably due to leaf soaking. However, there was no difference in fresh leaf weight loss (average: 67%) among sediment levels after one month. Fresh weight loss (range: 81

  17. Voices of Contact: Politics of Language in Urban Amazonian Ecuador

    Science.gov (United States)

    Wroblewski, Michael

    2010-01-01

    This dissertation is a study of diverse linguistic resources and contentious identity politics among indigenous Amazonian Kichwas in the city of Tena, Ecuador. Tena is a rapidly developing Amazonian provincial capital city with a long history of interethnic and interlinguistic contact. In recent decades, the course of indigenous Kichwa identity…

  18. Offering offspring as food to cannibals: oviposition strategies of Amazonian poison frogs (Dendrobates ventrimaculatus)

    NARCIS (Netherlands)

    Poelman, E.H.; Dicke, M.

    2007-01-01

    Species utilizing distinct resources for offspring production often show plasticity in reproductive strategies as a function of resource quality. For species using ephemeral pools, strategies are mainly shaped by a time constraint related to pool stability, resource availability and the colonizing

  19. Salmonella Infection and Water Frogs

    Centers for Disease Control (CDC) Podcasts

    2010-01-12

    This podcast, featuring lead investigator Shauna Mettee, discusses the first known outbreak of Salmonella in people due to contact with water frogs.  Created: 1/12/2010 by National Center for Zoonotic, Vector-Borne, and Enteric Diseases (NCZVED).   Date Released: 1/12/2010.

  20. Guinea Worm in a Frog

    Centers for Disease Control (CDC) Podcasts

    2017-03-09

    Dr. Mark Eberhard, a retired parasitologist and CDC guest researcher, discusses Guinea worm infection in a wild-caught frog.  Created: 3/9/2017 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 3/9/2017.

  1. FROGS (Friends of Granites) report

    Science.gov (United States)

    Miller, Calvin

    This VGP News, which is devoted to petrology, is a good one for noting the existence of FROGS. FROGS is, as the name suggests, an informal organization of people whose research relates in one way or another to granitic rocks. Its purpose has been to promote communication among geoscientists with different perspectives and concerns about felsic plutonism. Initially, a major focus was experimental petrology and integration of field-oriented and lab-oriented viewpoints; now that there is the opportunity to communicate with the Eos readership, an obvious additional goal will be to bring together volcanic and plutonic views of felsic magmatism.FROGS first gathered in late 1982 under the guidance of E-an Zen and Pete Toulmin (both at U.S. Geological Survey (USGS), Reston, Va.), who saw a need for greater interaction among those interested in granites and for renewed, focused experimental investigations. They produced two newsletters (which were sent out by direct mail) and organized an informal meeting at the Geological Society of America meeting at Indianapolis, Ind., and then turned over the FROG reins to Sue Kieffer (USGS, Flagstaff, Ariz.) and John Clemens (Arizona State University, Tempe). They generated another newsletter, which was directly mailed to a readership that had grown beyond 200.

  2. Mechanics of the frog ear

    NARCIS (Netherlands)

    Van Dijk, Pim; Mason, Matthew J.; Schoffelen, Richard L. M.; Narins, Peter M.; Meenderink, Sebastiaan W. F.

    The frog inner ear contains three regions that are sensitive to airborne sound and which are functionally distinct. (1) The responses of nerve fibres innervating the low-frequency, rostral part of the amphibian papilla (AP) are complex. Electrical tuning of hair cells presumably contributes to the

  3. CARE AND FEEDING OF FROGS

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Margaret; Chiang, Eugene, E-mail: mpan@astro.berkeley.edu [Department of Astronomy, University of California, Berkeley, CA 94720 (United States)

    2012-01-15

    'Propellers' are features in Saturn's A ring associated with moonlets that open partial gaps. They exhibit non-Keplerian motion (Tiscareno et al.); the longitude residuals of the best-observed propeller, 'Bleriot', appear consistent with a sinusoid of period {approx}4 years. Pan and Chiang proposed that propeller moonlets librate in 'frog resonances' with co-orbiting ring material. By analogy with the restricted three-body problem, they treated the co-orbital material as stationary in the rotating frame and neglected non-co-orbital material. Here we use simple numerical experiments to extend the frog model, including feedback due to the gap's motion, and drag associated with the Lindblad disk torques that cause Type I migration. Because the moonlet creates the gap, we expect the gap centroid to track the moonlet, but only after a time delay t{sub delay}, the time for a ring particle to travel from conjunction with the moonlet to the end of the gap. We find that frog librations can persist only if t{sub delay} exceeds the frog libration period P{sub lib}, and if damping from Lindblad torques balances driving from co-orbital torques. If t{sub delay} << Pl{sub ib}, then the libration amplitude damps to zero. In the case of Bleriot, the frog resonance model can reproduce the observed libration period P{sub lib} {approx_equal} 4 yr. However, our simple feedback prescription suggests that Bleriot's t{sub delay} {approx} 0.01P{sub lib}, which is inconsistent with the observed libration amplitude of 260 km. We urge more accurate treatments of feedback to test the assumptions of our toy models.

  4. CARE AND FEEDING OF FROGS

    International Nuclear Information System (INIS)

    Pan, Margaret; Chiang, Eugene

    2012-01-01

    'Propellers' are features in Saturn's A ring associated with moonlets that open partial gaps. They exhibit non-Keplerian motion (Tiscareno et al.); the longitude residuals of the best-observed propeller, 'Blériot', appear consistent with a sinusoid of period ∼4 years. Pan and Chiang proposed that propeller moonlets librate in 'frog resonances' with co-orbiting ring material. By analogy with the restricted three-body problem, they treated the co-orbital material as stationary in the rotating frame and neglected non-co-orbital material. Here we use simple numerical experiments to extend the frog model, including feedback due to the gap's motion, and drag associated with the Lindblad disk torques that cause Type I migration. Because the moonlet creates the gap, we expect the gap centroid to track the moonlet, but only after a time delay t delay , the time for a ring particle to travel from conjunction with the moonlet to the end of the gap. We find that frog librations can persist only if t delay exceeds the frog libration period P lib , and if damping from Lindblad torques balances driving from co-orbital torques. If t delay ib , then the libration amplitude damps to zero. In the case of Blériot, the frog resonance model can reproduce the observed libration period P lib ≅ 4 yr. However, our simple feedback prescription suggests that Blériot's t delay ∼ 0.01P lib , which is inconsistent with the observed libration amplitude of 260 km. We urge more accurate treatments of feedback to test the assumptions of our toy models.

  5. From frog integument to human skin: dermatological perspectives from frog skin biology

    NARCIS (Netherlands)

    Haslam, I.S.; Roubos, E.; Mangoni, M.L.; Yoshizato, K.; Vaudry, H.; Kloepper, J.E.; Pattwell, D.M.; Maderson, P.F.A.; Paus, R.

    2014-01-01

    For over a century, frogs have been studied across various scientific fields, including physiology, embryology, neuroscience, (neuro)endocrinology, ecology, genetics, behavioural science, evolution, drug development, and conservation biology. In some cases, frog skin has proven very successful as a

  6. Biogeography of Amazonian fishes: deconstructing river basins as biogeographic units

    Directory of Open Access Journals (Sweden)

    Fernando C. P. Dagosta

    2017-09-01

    Full Text Available ABSTRACT Biogeography of Amazonian fishes (2,500 species in vastly disjunct lineages is complex and has so far been approached only partially. Here, we tackle the problem on the basis of the largest database yet on geographical distribution and phylogenetic relationships of Amazonian fishes, including all information available. Distributions of 4,095 species (both Amazonian and outgroups and 84 phylogenetic hypotheses (comprising 549 phylogenetically-informative nodes were compiled, qualified and plotted onto 46 areas (29 Amazonian and 17 non-Amazonian. The database was analyzed with PAE, CADE, BPA and BPA0, yielding largely congruent results and indicating that biogeographic signal is detectable on multiple dimensions of fish distribution, from single species ranges to cladistic congruence. Agreement is especially pronounced in deeper components, such as Trans-Andean, Cis-Andean, Western Amazon and Orinoco basins. Results show that all major Amazonian tributaries, as well as the Amazon basin itself, are non-monophyletic and constitute hybrid sets of heterogeneous biotic partitions. Amazonian drainages should not be assumed a priori as historically cohesive areas, contrary to widespread practice. Our hypothesis allows re-evaluation of broader issues in historical biogeography, such as the predictive power of biogeographic hypotheses, the vicariant/dispersal duality, the significance of widely distributed taxa, and the need for temporal dimension in biogeographic patterns.

  7. Origin and Domestication of Native Amazonian Crops

    Directory of Open Access Journals (Sweden)

    Doriane Picanço-Rodrigues

    2010-01-01

    Full Text Available Molecular analyses are providing new elements to decipher the origin, domestication and dispersal of native Amazonian crops in an expanding archaeological context. Solid molecular data are available for manioc (Manihot esculenta, cacao (Theobroma cacao, pineapple (Ananas comosus, peach palm (Bactris gasipaes and guaraná (Paullinia cupana, while hot peppers (Capsicum spp., inga (Inga edulis, Brazil nut (Bertholletia excelsa and cupuassu (Theobroma grandiflorum are being studied. Emergent patterns include the relationships among domestication, antiquity (terminal Pleistocene to early Holocene, origin in the periphery, ample pre-Columbian dispersal and clear phylogeographic population structure for manioc, pineapple, peach palm and, perhaps, Capsicum peppers. Cacao represents the special case of an Amazonian species possibly brought into domestication in Mesoamerica, but close scrutiny of molecular data suggests that it may also have some incipiently domesticated populations in Amazonia. Another pattern includes the relationships among species with incipiently domesticated populations or very recently domesticated populations, rapid pre- or post-conquest dispersal and lack of phylogeographic population structure, e.g., Brazil nut, cupuassu and guaraná. These patterns contrast the peripheral origin of most species with domesticated populations with the subsequent concentration of their genetic resources in the center of the basin, along the major white water rivers where high pre-conquest population densities developed. Additional molecular genetic analyses on these and other species will allow better examination of these processes and will enable us to relate them to other historical ecological patterns in Amazonia.

  8. Hyperdominance in Amazonian forest carbon cycling.

    Science.gov (United States)

    Fauset, Sophie; Johnson, Michelle O; Gloor, Manuel; Baker, Timothy R; Monteagudo M, Abel; Brienen, Roel J W; Feldpausch, Ted R; Lopez-Gonzalez, Gabriela; Malhi, Yadvinder; ter Steege, Hans; Pitman, Nigel C A; Baraloto, Christopher; Engel, Julien; Pétronelli, Pascal; Andrade, Ana; Camargo, José Luís C; Laurance, Susan G W; Laurance, William F; Chave, Jerôme; Allie, Elodie; Vargas, Percy Núñez; Terborgh, John W; Ruokolainen, Kalle; Silveira, Marcos; Aymard C, Gerardo A; Arroyo, Luzmila; Bonal, Damien; Ramirez-Angulo, Hirma; Araujo-Murakami, Alejandro; Neill, David; Hérault, Bruno; Dourdain, Aurélie; Torres-Lezama, Armando; Marimon, Beatriz S; Salomão, Rafael P; Comiskey, James A; Réjou-Méchain, Maxime; Toledo, Marisol; Licona, Juan Carlos; Alarcón, Alfredo; Prieto, Adriana; Rudas, Agustín; van der Meer, Peter J; Killeen, Timothy J; Marimon Junior, Ben-Hur; Poorter, Lourens; Boot, Rene G A; Stergios, Basil; Torre, Emilio Vilanova; Costa, Flávia R C; Levis, Carolina; Schietti, Juliana; Souza, Priscila; Groot, Nikée; Arets, Eric; Moscoso, Victor Chama; Castro, Wendeson; Coronado, Euridice N Honorio; Peña-Claros, Marielos; Stahl, Clement; Barroso, Jorcely; Talbot, Joey; Vieira, Ima Célia Guimarães; van der Heijden, Geertje; Thomas, Raquel; Vos, Vincent A; Almeida, Everton C; Davila, Esteban Álvarez; Aragão, Luiz E O C; Erwin, Terry L; Morandi, Paulo S; de Oliveira, Edmar Almeida; Valadão, Marco B X; Zagt, Roderick J; van der Hout, Peter; Loayza, Patricia Alvarez; Pipoly, John J; Wang, Ophelia; Alexiades, Miguel; Cerón, Carlos E; Huamantupa-Chuquimaco, Isau; Di Fiore, Anthony; Peacock, Julie; Camacho, Nadir C Pallqui; Umetsu, Ricardo K; de Camargo, Plínio Barbosa; Burnham, Robyn J; Herrera, Rafael; Quesada, Carlos A; Stropp, Juliana; Vieira, Simone A; Steininger, Marc; Rodríguez, Carlos Reynel; Restrepo, Zorayda; Muelbert, Adriane Esquivel; Lewis, Simon L; Pickavance, Georgia C; Phillips, Oliver L

    2015-04-28

    While Amazonian forests are extraordinarily diverse, the abundance of trees is skewed strongly towards relatively few 'hyperdominant' species. In addition to their diversity, Amazonian trees are a key component of the global carbon cycle, assimilating and storing more carbon than any other ecosystem on Earth. Here we ask, using a unique data set of 530 forest plots, if the functions of storing and producing woody carbon are concentrated in a small number of tree species, whether the most abundant species also dominate carbon cycling, and whether dominant species are characterized by specific functional traits. We find that dominance of forest function is even more concentrated in a few species than is dominance of tree abundance, with only ≈1% of Amazon tree species responsible for 50% of carbon storage and productivity. Although those species that contribute most to biomass and productivity are often abundant, species maximum size is also influential, while the identity and ranking of dominant species varies by function and by region.

  9. Naturally occurring fluorescence in frogs.

    Science.gov (United States)

    Taboada, Carlos; Brunetti, Andrés E; Pedron, Federico N; Carnevale Neto, Fausto; Estrin, Darío A; Bari, Sara E; Chemes, Lucía B; Peporine Lopes, Norberto; Lagorio, María G; Faivovich, Julián

    2017-04-04

    Fluorescence, the absorption of short-wavelength electromagnetic radiation reemitted at longer wavelengths, has been suggested to play several biological roles in metazoans. This phenomenon is uncommon in tetrapods, being restricted mostly to parrots and marine turtles. We report fluorescence in amphibians, in the tree frog Hypsiboas punctatus, showing that fluorescence in living frogs is produced by a combination of lymph and glandular emission, with pigmentary cell filtering in the skin. The chemical origin of fluorescence was traced to a class of fluorescent compounds derived from dihydroisoquinolinone, here named hyloins. We show that fluorescence contributes 18-29% of the total emerging light under twilight and nocturnal scenarios, largely enhancing brightness of the individuals and matching the sensitivity of night vision in amphibians. These results introduce an unprecedented source of pigmentation in amphibians and highlight the potential relevance of fluorescence in visual perception in terrestrial environments.

  10. A Bilingual Experiment in the Amazonian Jungle of Peru

    Science.gov (United States)

    Wise, Mary Ruth

    1971-01-01

    In the Amazonian jungle of Peru 240 Indian leaders representing 20 different South American Indian language groups are successfully teaching their own people to read and write, first in their mother tongue and then in Spanish. (Author/EB)

  11. Snoring puddle frog

    International Nuclear Information System (INIS)

    Lloyd, Mark Anthony

    2000-01-01

    Full text: The purpose of this paper is to hold a biological mirror in front of ourselves, the nuclear energy community, and to suggest that the reflection we will see there will help us both professionally and as members of a broader society. Let us start with sex. For sex to function as a means of reproduction, a male and a female of a particular species have to recognise each other and mate. The important terms here are 'particular species' and 'recognise'. Within most species, extraordinarily precise mate recognition systems have evolved. The precise frequency of the croak of a particular species of frog; the precise seasonal coloration of a particular species of salmon; the precise length of the tail of a particular species of bird; each is recognisable instantly to a prospective mate, though not to untrained human ears or eyes. 'The Recognition Concept of Species' (1985) is a monograph that has become something of a 'classic' in annals of evolutionary biology. Its author, HEH Paterson, suggests that a species can be defined as a group of organisms that share a common mate recognition system. Mating is an exchange of genes, and creatures that do not recognise each other do not exchange genes. A mate recognition system closes off the gene pool and may increasingly isolate its participants from even their nearest relatives. Biological evolution has numerous links and parallels with the evolution of human cultures. Some of our recognition systems seem to have a knack for drawing everyone in - American popular culture, for example, is now inescapable. Other recognition systems repel all but a few - take, or rather don't take, the Hell's Angels or the Ku Klux Klan. We, as members of the nuclear energy culture, are members of a closed and even repellent gene pool. We share a recognition system by which we perpetuate ourselves from generation to generation, from Hiroshima to Chernobyl. Outsiders do not understand our language: terms like 'credit for fission products

  12. Placentation in the Amazonian manatee (Trichechus inunguis)

    DEFF Research Database (Denmark)

    Carter, A M; Miglino, M A; Ambrosio, C E

    2008-01-01

    Evidence from several sources supports a close phylogenetic relationship between elephants and sirenians. To explore whether this was reflected in similar placentation, we examined eight delivered placentae from the Amazonian manatee using light microscopy and immunohistochemistry. In addition......, the fetal placental circulation was described by scanning electron microscopy of vessel casts. The manatee placenta was zonary and endotheliochorial, like that of the elephant. The interhaemal barrier comprised maternal endothelium, cytotrophoblasts and fetal endothelium. We found columnar trophoblast...... beneath the chorionic plate and lining lacunae in this region, but there was no trace in the term placenta of haemophagous activity. The gross anatomy of the cord and fetal membranes was consistent with previous descriptions and included a four-chambered allantoic sac, as also found in the elephant...

  13. The Ups and Downs of Frogs.

    Science.gov (United States)

    Greene, Janice Schnake; Tamme, Tina

    2001-01-01

    Presents a science activity in which students simulate increases and decreases in frog populations to get a better understanding of different environmental issues affecting animal populations. Includes simulations for both natural frog populations as well as populations affected by human activities. (YDS)

  14. Semi-automated identification of leopard frogs

    Science.gov (United States)

    Petrovska-Delacrétaz, Dijana; Edwards, Aaron; Chiasson, John; Chollet, Gérard; Pilliod, David S.

    2014-01-01

    Principal component analysis is used to implement a semi-automatic recognition system to identify recaptured northern leopard frogs (Lithobates pipiens). Results of both open set and closed set experiments are given. The presented algorithm is shown to provide accurate identification of 209 individual leopard frogs from a total set of 1386 images.

  15. The frog inner ear : picture perfect?

    NARCIS (Netherlands)

    Mason, Matthew J.; Segenhout, Johannes M.; Cobo-Cuan, Ariadna; Quiones, Patricia M.; van Dijk, Pim

    Many recent accounts of the frog peripheral auditory system have reproduced Wever's (1973) schematic cross-section of the ear of a leopard frog. We sought to investigate to what extent this diagram is an accurate and representative depiction of the anuran inner ear, using three-dimensional

  16. Value of Riparian Vegetation Remnants for Leaf-Litter Ants (Hymenoptera: Formicidae) in a Human-Dominated Landscape in Central Veracruz, Mexico.

    Science.gov (United States)

    García-Martínez, Miguel Á; Escobar-Sarria, Federico; López-Barrera, Fabiola; Castaño-Meneses, Gabriela; Valenzuela-González, Jorge E

    2015-12-01

    Riparian remnants are linear strips of vegetation immediately adjacent to rivers that may act as refuges for biodiversity, depending on their habitat quality. In this study, we evaluated the role of riparian remnants in contributing to the diversity of leaf-litter ants by determining the relationship between ant diversity and several riparian habitat characteristics within a human-dominated landscape in Veracruz, Mexico. Sampling was carried out in 2012 during both dry and rainy seasons at 12 transects 100 m in length, where 10 leaf-litter samples were collected along each transect and processed with Berlese-Tullgren funnels and Winkler sacks. A total of 8,684 individuals belonging to 53 species, 22 genera, and seven subfamilies were collected. The observed mean alpha diversity accounted for 34.4% of the total species recorded and beta diversity for 65.6%. Species richness and composition were significantly related to litter-layer depth and soil compaction, which could limit the distribution of ant species depending on their nesting, feeding, and foraging habits. Riparian remnants can contribute toward the conservation of ant assemblages and likely other invertebrate communities that are threatened by anthropogenic pressures. In human-dominated landscapes where remnants of riparian vegetation give refuge to a diverse array of myrmecofauna, the protection of the few remaining and well-preserved riparian sites is essential for the long-term maintenance of biodiversity. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. On the Uniqueness of FROG Methods

    Science.gov (United States)

    Bendory, Tamir; Sidorenko, Pavel; Eldar, Yonina C.

    2017-05-01

    The problem of recovering a signal from its power spectrum, called phase retrieval, arises in many scientific fields. One of many examples is ultra-short laser pulse characterization in which the electromagnetic field is oscillating with ~10^15 Hz and phase information cannot be measured directly due to limitations of the electronic sensors. Phase retrieval is ill-posed in most cases as there are many different signals with the same Fourier transform magnitude. To overcome this fundamental ill-posedness, several measurement techniques are used in practice. One of the most popular methods for complete characterization of ultra-short laser pulses is the Frequency-Resolved Optical Gating (FROG). In FROG, the acquired data is the power spectrum of the product of the unknown pulse with its delayed replica. Therefore the measured signal is a quartic function of the unknown pulse. A generalized version of FROG, where the delayed replica is replaced by a second unknown pulse, is called blind FROG. In this case, the measured signal is quadratic with respect to both pulses. In this letter we introduce and formulate FROG-type techniques. We then show that almost all band-limited signals are determined uniquely, up to trivial ambiguities, by blind FROG measurements (and thus also by FROG), if in addition we have access to the signals power spectrum.

  18. Eleutherodactylus frog introductions to Hawaii

    Science.gov (United States)

    Kraus, Fred; Campbell, Earl W.; Allison, Allen; Pratt, Thane K.

    1999-01-01

    As an oceanic archipelago isolated from continental source areas, Hawaii lacks native terrestrial reptiles and amphibians, Polynesians apparently introduced seven gecko and skink species after discovering the islands approximately 1500 years ago, and another 15 reptiles and five frogs have been introduced in the last century and a half (McKeown 1996). The Polynesian introductions are probably inadvertent because the species involved are known stowaway dispersers (Gibbons 1985; Dye and Steadman 1990), In contrast, most of the herpetological introductions since European contact with Hawaii have been intentional. Several frog species were released for biocontrol of insects (e.g., Dendrobates auratus, Bufo marinus, Rana rugosa, Bryan 1932; Oliver and Shaw 1953), and most of the remaining species are released or escaped pets (e.g., Phelsuma spp., Chamaeleo jacksonii, Iguana iguana, McKeown 1996), Government-approved releases have not occurred for many years, but the rate of establishment of new species has increased in the past few decades because of the importation and subsequent release of pets.

  19. Meeting the "Standards" with Vanishing Frogs.

    Science.gov (United States)

    Davidson, Cindy B.; Matthews, Catherine E.; Patrick, Patricia

    2001-01-01

    Explains methods for introducing high school students to the issue of the declining amphibian population. Plays the game Frogs' Futures following a seminar as an instructional strategy. Describes the game, procedures, and rules. (YDS)

  20. FROGS Report Friends of Granite Summer 1989

    Science.gov (United States)

    FROGS Reports present information on current research relevant to felsic magmatism, including commentaries on problems of current interest. Please contact Calvin Miller (6028B, Vanderbilt University, Nashville, TN 37235) concerning your own research, conferences, and ideas for stimulating commentaries.

  1. A new species of small tree frog, genus Dendropsophus (Anura: Hylidae) from the eastern Amazon lowlands of Ecuador.

    Science.gov (United States)

    Ortega-Andrade, H Mauricio; Ron, Santiago R

    2013-01-01

    We describe a new species of the hylid frog genus Dendropsophus from Amazonian Ecuador. The new species, Dendropsophus shiwiarum sp. nov., appears to be part of the D. microcephalus species group. Dendropsophus shiwiarum differs from its congeners by a combination of: (1) tympanic membrane non-differentiated and annulus evident only ventrally, (2) disc of Finger III and Toe IV with pointed tip, (3) dorsal surfaces of digital discs with a conical tubercle as result of projection of distal phalanx, and (4) small size (SVL < 19 mm). The new species is morphologically most similar to Dendropsophus riveroi. Examination of the type material of the latter suggests that some Ecuadorian populations reported as D. riveroi were misidentified and in fact belong to D. shiwiarum sp. nov.

  2. Development of the pseudothumb in frogs

    Science.gov (United States)

    Tokita, Masayoshi; Iwai, Noriko

    2010-01-01

    Frogs have highly conserved hand and foot morphology, possessing four fingers and five toes. As an exception, two Japanese ranid frog species, the Otton frog Babina subaspera and the dagger frog Babina holsti, possess a unique thumb-like structure (the pseudothumb) in the forelimb, giving an appearance of a total of five fingers on the hand. To obtain insights into the developmental mechanisms that generate this novel character, we investigated the hand morphogenesis of the Otton frog. The unique morphological pattern of the pseudothumb was already established in juveniles. Surprisingly, the bud-like structure, which is similar to the area of inductive activity (e.g. feather buds in birds and the carapacial ridge in turtles), was detected over the site where the future prepollex develops in larvae. By contrast, this bud-like structure was not found in larvae of other ranid species. We discuss possible scenarios that would favour the evolution of this very unusual trait in frogs. PMID:20147308

  3. An assessment of leaf-litter and epigaeic ants (Hymenoptera: Formicidae living in different landscapes of the Atlantic Forest Biome in the State of Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Roberta de Jesus Santos

    2017-11-01

    Full Text Available The Brazilian Atlantic Forest has a rich biodiversity increasingly threatened by human activities. Since the colonial period, the coast of the state of Bahia is among the most affected regions of Brazil by anthropic pressure. Bahia encloses Atlantic Forest remnants distributed in an area reaching 100-200 km along the east-west axis, by 1,000 km along the north-south axis, parallel to the coast of the Atlantic Ocean. We report hereafter the results of an intensive field survey of leaf litter and epigaeic ants realized in forest remnants of the Atlantic Forest landscapes within the original extension of the biome in 11 localities distributed along four degrees of latitude in the state of Bahia. In each site, 16 plots were collected using pitfall and eight using Winkler traps. We identified 391 ant species belonging to 71 genera and nine subfamilies. Among all species recorded, 21 were common to the whole 11 localities, while 98 species were recorded in a single locality. This study highlights the richness and diversity of epigaeic and leaf-litter ants living in the northern part of the Brazilian Atlantic Forest, and is one of the most representative soil ants’ inventories ever done in this biome for a single state of Brazil.

  4. Correspondence: Rapid tree carbon stock recovery in managed Amazonian forests

    NARCIS (Netherlands)

    Rutishauser, E.; Hérault, B.; Baraloto, C.; Blanc, L.; Descroix, L.; Sotta, E.; Ferreira, J.; Kanashiro, M.; Mazzei, L.; Pena Claros, M.

    2015-01-01

    While around 20% of the Amazonian forest has been cleared for pastures and agriculture, one fourth of the remaining forest is dedicated to wood production [1]. Most of these production forests have been or will be selectively harvested for commercial timber, but recent studies show that even soon

  5. The Amazonian Formative: Crop Domestication and Anthropogenic Soils

    Directory of Open Access Journals (Sweden)

    Manuel Arroyo-Kalin

    2010-03-01

    Full Text Available The emergence of sedentism and agriculture in Amazonia continues to sit uncomfortably within accounts of South American pre-Columbian history. This is partially because deep-seated models were formulated when only ceramic evidence was known, partly because newer data continue to defy simple explanations, and partially because many discussions continue to ignore evidence of pre-Columbian anthropogenic landscape transformations. This paper presents the results of recent geoarchaeological research on Amazonian anthropogenic soils. It advances the argument that properties of two different types of soils, terras pretas and terras mulatas, support their interpretation as correlates of, respectively, past settlement areas and fields where spatially-intensive, organic amendment-reliant cultivation took place. This assessment identifies anthropogenic soil formation as a hallmark of the Amazonian Formative and prompts questions about when similar forms of enrichment first appear in the Amazon basin. The paper reviews evidence for embryonic anthrosol formation to highlight its significance for understanding the domestication of a key Amazonian crop: manioc (Manihot esculenta ssp. esculenta. A model for manioc domestication that incorporates anthropogenic soils outlines some scenarios which link the distribution of its two broader varieties—sweet and bitter manioc—with the widespread appearance of Amazonian anthropogenic dark earths during the first millennium AD.

  6. Fungal community assembly in the Amazonian Dark Earth

    NARCIS (Netherlands)

    Reis Lucheta, Adriano; Souza Cannavan, F.S.; Roesch, L.; Tsai, S.M.; Kuramae, E.E.

    2016-01-01

    Here, we compare the fungal community composition and diversity in Amazonian Dark Earth (ADE) and the respective non-anthropogenic origin adjacent (ADJ) soils from four different sites in Brazilian Central Amazon using pyrosequencing of 18S ribosomal RNA (rRNA) gene. Fungal community composition in

  7. 49 CFR 213.139 - Spring rail frogs.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Spring rail frogs. 213.139 Section 213.139..., DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.139 Spring rail frogs. (a) The... wing rail shall be solidly tamped and fully and tightly bolted. (c) Each frog with a bolt hole defect...

  8. 49 CFR 213.141 - Self-guarded frogs.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Self-guarded frogs. 213.141 Section 213.141..., DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.141 Self-guarded frogs. (a) The raised guard on a self-guarded frog shall not be worn more than three-eighths of an inch. (b) If repairs...

  9. Prototype next generation frog foundation - preliminary evaluation : research results.

    Science.gov (United States)

    2016-06-01

    Conventional wisdom suggests that a solid or rigid one-piece frog is preferred because it is easy to maintain. However, testing and subsequent modeling demonstrated that a flexible frog (i.e., a two-piece frog split in the flangeway) produced signifi...

  10. THE PROPELLER AND THE FROG

    International Nuclear Information System (INIS)

    Pan, Margaret; Chiang, Eugene

    2010-01-01

    'Propellers' in planetary rings are disturbances in ring material excited by moonlets that open only partial gaps. We describe a new type of co-orbital resonance that can explain the observed non-Keplerian motions of propellers. The resonance is between the moonlet underlying the propeller and co-orbiting ring particles downstream of the moonlet where the gap closes. The moonlet librates within the gap about an equilibrium point established by co-orbiting material and stabilized by the Coriolis force. In the limit of small libration amplitude, the libration period scales linearly with the gap azimuthal width and inversely as the square root of the co-orbital mass. The new resonance recalls but is distinct from conventional horseshoe and tadpole orbits; we call it the 'frog' resonance, after the relevant term in equine hoof anatomy. For a ring surface density and gap geometry appropriate for the propeller Bleriot in Saturn's A ring, our theory predicts a libration period of ∼4 years, similar to the ∼3.7 year period over which Bleriot's orbital longitude is observed to vary. These librations should be subtracted from the longitude data before any inferences about moonlet migration are made.

  11. A new morphologically cryptic species of Phyllomedusa (Anura: Phyllomedusidae) from Amazonian forests of northern Peru revealed by DNA sequences.

    Science.gov (United States)

    Castroviejo-Fisher, Santiago; Köhler, Jörn; Riva, Ignacio DE LA; Padial, José M

    2017-05-22

    We describe and name Phyllomedusa chaparroi sp. nov., a medium-sized species (snout-vent length in adult males 67.9-77.5 mm) of monkey frog from Amazonian rainforests of northern Peru. Although morphologically most similar to P. boliviana and P. camba (indistinguishable from the latter in external qualitative and quantitative traits), phylogenetic analysis of combined mitochondrial and nuclear markers place the new species sister to a clade containing P. neildi, P. tarsius, and P. trinitatis. Phyllomedusa chaparroi can be readily differentiated from these species by having a dark reddish-brown iris with indistinct tiny orange spots versus an orange iris with marked dark reticulation found in P. neildi, P. tarsius, and P. trinitatis. Furthermore, genetic distances for a 532 bp sequence of the 16S gene between the new species and its sister species are 2.8-4.1 %, whereas distances are 4.5-5.5 % to the morphologically cryptic P. camba. We briefly discuss the importance of DNA sequences in revealing morphologically cryptic species and modify the content of the P. tarsius species group based on phylogenetic analyses and observations on iris coloration.

  12. Visual mate choice in poison frogs.

    Science.gov (United States)

    Summers, K; Symula, R; Clough, M; Cronin, T

    1999-11-07

    We investigated female mate choice on the basis of visual cues in two populations of Dendrobates pumilio, the strawberry poison frog, from the Bocas del Toro Archipelago in Panama, Central America. Mate choice experiments were carried out by presenting subject females of each of two morphs of this species (orange and green) from two different island populations (Nancy Key and Pope Island) with object frogs (one of each morph) under glass at one end of a terrarium. Recorded calls were played simultaneously from behind both object frogs. The experiments were carried out under two light regimes: (i) white light, and (ii) relatively monochromatic filtered blue light. Subject females from each population displayed a significant preference for their own morph under white light, but not under blue light. These results indicate that female D. pumilio use visual cues in mate choice, and suggest that colour may be the visual cue they use.

  13. FROG The Fast and Realistic OPENGL Displayer

    CERN Document Server

    Quertenmont, Loic

    2009-01-01

    FROG is a generic framework dedicated to visualisation of events in high energy experiment. It is suitable to any particular physics experiment or detector design. The code is light ($<3\\textrm{MB}$) and fast (browsing time ~20 events per second for a large High Energy Physics experiment) and can run on various operating systems, as its object-oriented structure (C++) relies on the cross-platform OPENGL and GLUT libraries. Moreover, FROG does not require installation of third party libraries for the visualisation. This document describes the features and principles of FROG version 1.106, its working scheme and numerous functionalities such as: 3D and 2D visualisations, graphical user interface, mouse interface, configuration files, production of pictures of various format, integration of personal objects, etc. Finally, several examples of its current applications are presented for illustration.

  14. FROGS (Friends of Granites) Report, summer 1988

    Science.gov (United States)

    DeYoreo, J. J.; Wickham, Stephen M.; Miller, Calvin

    This is the second Eos-published FROGS Report. Our purpose is to disseminate information and stimulate thinking concerning felsic magmatism in general and granitoids in particular. We intend to publish semiannually information about events and publications that are relevant to the study of felsic rocks, brief updates on research being done by granitoid researchers, and commentaries on important new and/or controversial themes. FROGS Reports is critically dependent upon response by those with an interest in research on felsic rocks. Please keep me (Calvin Miller, 6028B, Vanderbilt Univ., Nashville TN 37235) informed about upcoming or recent conferences, major publications, etc. Also, send me your suggestions for topics for (and/or volunteer to write) pertinent commentaries for FROGS Reports.

  15. Muscles of the pes of hylid frogs.

    Science.gov (United States)

    Burton, Thomas C

    2004-05-01

    Complete or partial dissection of the foot musculature of 404 hylid frogs representing 247 species and 33 genera, along with representatives of eight other families, revealed a number of apomorphic characters that distinguish the hyloid frogs (Hylidae plus Allophryne and Centrolenidae) from other bufonoid frogs. Additional characters were found to define some of the hylid subfamilies. Addition of characters from the foot musculature to Duellman's phylogenetic tree of the hyloids produced a tree in which Allophryne and Centrolenidae are nested within Hylidae. Support was found for the monophyly of the 30-chromosome group within Hyla, and for a large number of the groups that comprise "Boana," viz., the Hyla albomarginata, H. albopunctata, H. boans (except H. vasta), H. geographica, and H. pulchella groups, but foot muscle characters provide no information relating to relationships of the West Indies hylines. Copyright 2004 Wiley-Liss, Inc.

  16. FROGS (Friends of Granites) Report, Fall 1987

    Science.gov (United States)

    Miller, Calvin F.; Lawford, J.

    This is the first official FROGS report in Eos. Our purpose is to disseminate information about the status of felsic igneous petrology, providing information and opinions about research, ideas, and problems that relate especially to granitoids but also, clearly, to felsic volcanic rocks. A major goal has been to bridge the gap between field-based and experimental approaches. For several years, FROGS reports have existed as occasional informal newsletters, but we feel that our purposes will be better served by semiannual publication as a section of the VGP News. A briefer companion report will also be published in The Lattice, the newsletter of the Mineralogical Society of America.

  17. Birds and frogs in mathematics and physics

    International Nuclear Information System (INIS)

    Dyson, Freeman J

    2010-01-01

    Some scientists are birds, others are frogs. Birds fly high in the air and survey broad vistas of mathematics out to the far horizon. They delight in concepts that unify our thinking and bring together diverse problems from different parts of the landscape. Frogs live in the mud below and see only the flowers that grow nearby. They delight in the details of particular objects, and they solve problems one at a time. A brief history of mathematics and its applications in physics is presented in this article. (from the history of physics)

  18. Do all frogs swim alike? The effect of ecological specialization on swimming kinematics in frogs.

    Science.gov (United States)

    Robovska-Havelkova, Pavla; Aerts, Peter; Rocek, Zbynek; Prikryl, Tomas; Fabre, Anne-Claire; Herrel, Anthony

    2014-10-15

    Frog locomotion has attracted wide scientific interest because of the unusual and derived morphology of the frog pelvic girdle and hind limb. Previous authors have suggested that the design of the frog locomotor system evolved towards a specialized jumping morphology early in the radiation of the group. However, data on locomotion in frogs are biased towards a few groups and most of the ecological and functional diversity remains unexplored. Here, we examine the kinematics of swimming in eight species of frog with different ecologies. We use cineradiography to quantify movements of skeletal elements from the entire appendicular skeleton. Our results show that species with different ecologies do differ in the kinematics of swimming, with the speed of limb extension and especially the kinematics of the midfoot being different. Our results moreover suggest that this is not a phylogenetic effect because species from different clades with similar ecologies converge on the same swimming kinematics. We conclude that it is important to analyze frog locomotion in a broader ecological and evolutionary context if one is to understand the evolutionary origins of this behavior. © 2014. Published by The Company of Biologists Ltd.

  19. Millennial-scale dynamics of southern Amazonian rain forests.

    Science.gov (United States)

    Mayle, F E; Burbridge, R; Killeen, T J

    2000-12-22

    Amazonian rain forest-savanna boundaries are highly sensitive to climatic change and may also play an important role in rain forest speciation. However, their dynamics over millennial time scales are poorly understood. Here, we present late Quaternary pollen records from the southern margin of Amazonia, which show that the humid evergreen rain forests of eastern Bolivia have been expanding southward over the past 3000 years and that their present-day limit represents the southernmost extent of Amazonian rain forest over at least the past 50,000 years. This rain forest expansion is attributed to increased seasonal latitudinal migration of the Intertropical Convergence Zone, which can in turn be explained by Milankovitch astronomic forcing.

  20. Amazonian Dark Earths: pathways to sustainable development in tropical rainforests?

    Directory of Open Access Journals (Sweden)

    Morgan Schmidt

    2013-04-01

    Full Text Available Fertile dark anthrosols associated with pre-Columbian settlement across the Amazon Basin have sparked wide interest for their potential contribution to sustainable use and management of tropical soils and ecosystems. In the Upper Xingu region of the southern Amazon, research on archaeological settlements and among contemporary descendant populations provides critical new data on the formation and use of anthrosols. These findings provide a basis for describing the variability of soil modifications that result from diverse human activities and a general model for the formation of Amazonian anthrosols. They underscore the potential for indigenous systems of knowledge and resource management to inform efforts for conservation and sustainable development of Amazonian ecosystems.

  1. Fish complementarity is associated to forests in Amazonian streams

    Directory of Open Access Journals (Sweden)

    Carolina Rodrigues Bordignon

    Full Text Available The functional structure of communities is commonly measured by the variability in functional traits, which may demonstrate complementarity or redundancy patterns. In this study, we tested the influence of environmental variables on the functional structure of fish assemblages in Amazonian streams within a deforestation gradient. We calculated six ecomorphological traits related to habitat use from each fish species, and used them to calculate the net relatedness index (NRI and the nearest taxon index (NTI. The set of species that used the habitat differently (complementary or overdispersed assemblages occurred in sites with a greater proportion of forests. The set of species that used the habitat in a similar way (redundant or clustered assemblages occurred in sites with a greater proportion of grasses in the stream banks. Therefore, the deforestation of entire watersheds, which has occurred in many Amazonian regions, may be a central factor for the functional homogenization of fish fauna.

  2. New species of Monostylis Tulasne (Podostemaceae from the Amazonian region

    Directory of Open Access Journals (Sweden)

    Aldalea Sprada Tavares

    2015-06-01

    Full Text Available http://dx.doi.org/10.5007/2175-7925.2015v28n3p15 Until now, Monostylis Tulasne (Podostemaceae was considered monospecific, containing only M. capillacea Tulasne. However, recent field expeditions and an analysis of samples from the Amazonian region revealed three new species, Monostylis aripuanensis, M. goeldiana and M. paraensis. The present paper provides detailed morphological descriptions, illustrations, habitat data, comparative taxonomic comments and a dichotomous key to the species.

  3. Mosquitoes of eastern Amazonian Ecuador: biodiversity, bionomics and barcodes

    OpenAIRE

    Yvonne-Marie Linton; James E Pecor; Charles H Porter; Luke Brett Mitchell; Andres Garzon-Moreno; Desmond H Foley; David Brooks Pecor; Richard C Wilkerson

    2013-01-01

    Two snapshot surveys to establish the diversity and ecological preferences of mosquitoes (Diptera: Culicidae) in the terra firme primary rain forest surrounding the Tiputini Biodiversity Station in the UNESCO Yasuní Biosphere Reserve of eastern Amazonian Ecuador were carried out in November 1998 and May 1999. The mosquito fauna of this region is poorly known; the focus of this study was to obtain high quality link-reared specimens that could be used to unequivocally confirm species level...

  4. Vectorcardiogram of the 'Man-Frog'

    African Journals Online (AJOL)

    TYDSKRIF. Vectorcardiogram of the 'Man-Frog'. 1095. A. SKOWRON,. SUMMARY. New experimental evidence is adduced to show that the hypothesis of the single instantaneous equivalent or resul- tant cardiac vector-which forms the basic concept of vectorcardiography - no matter whether this is produced by a dipole or a ...

  5. Water Frogs, Aquariums, and Salmonella -- Oh My!

    Centers for Disease Control (CDC) Podcasts

    2009-12-09

    This CDC Kidtastics podcast discusses how people can get Salmonella from water frogs and aquariums.  Created: 12/9/2009 by National Center for Zoonotic, Vector-Borne, and Enteric Diseases (NCZVED).   Date Released: 12/9/2009.

  6. Of volcanoes, saints, trash, and frogs

    DEFF Research Database (Denmark)

    Andersen, Astrid Oberborbeck

    , at the same time as political elections and economic hardship. During one year of ethnographic fieldwork volcanoes, saints, trash and frogs were among the nonhuman entities referred to in conversations and engaged with when responding to the changes that trouble the world and everyday life of Arequipans...

  7. A new grass frog from Namibia

    African Journals Online (AJOL)

    A new species of grass frog of the genus Ptychadena is described from northern Namibia. Although superficially similar to Ptychadena schilJukorum and Ptychadsna mossambica. the new species differs In advenisemen1 call, and erlernal charaders. An examination of a series of published sonagrams indicates.

  8. Frogs report: Friends of Granite, Winter 1990

    Science.gov (United States)

    FROGS reports present information on current research relevant to felsic magmatism, including commentaries on problems of current interest. Please contact Calvin Miller (Geology, 6028B, Vanderbilt University, Nashville, TN 37235, tel. 615-322-2986) about your own research, conferences, and ideas for stimulating commentaries.

  9. Return of the Tarahumara frog to Arizona

    Science.gov (United States)

    James C. Rorabaugh; Stephen F. Hale; Michael J. Sredl; Craig Ivanyi

    2005-01-01

    The last wild Tarahumara frog (Rana tarahumarae) in Arizona was found dead in Big Casa Blanca Canyon, Santa Rita Mountains, in May 1983. However, the species is still well represented in the majority of its range in the northern Sierra Madre Occidental and adjacent Sky Islands of Sonora and Chihuahua. Plans to re-establish R. tarahumarae...

  10. Frog egg growth, experiment S003

    Science.gov (United States)

    Young, R. S.; Tremor, J. W.

    1971-01-01

    The objective of experiment was to determine the effect of weightlessness on the ability of a fertilized frog egg to divide normally and to differentiate and form a normal embryo. This experiment was first attempted on the Gemini 8 mission and was completed only partially because of the early termination of that mission.

  11. Frog experiment onboard space station Mir.

    Science.gov (United States)

    Izumi-Kurotani, A; Mogami, Y; Okuno, M; Yamashita, M

    1997-01-01

    Japanese tree frogs (Hyla japonica) showed unique postures and behavior during an 8-day flight to the Russian space station Mir. When floating in the air, the animals arched their back and extended their four limbs. This posture resembles that observed during jumping or parachuting of the animals on the ground. Frog sitting on a surface bent their neck backward sharply, did not fold their hind limbs completely, and pressed their abdomen against the substrate. They walked backwards in this posture. The typical posture resembles that adopted during the emetic behavior process on the ground, although the posture in space lasts much longer. The possible mechanism of induction of this unique posture in orbit is discussed. Frogs in this posture might be in an emetic state, possibly due to motion sickness. Response behavior to some stimuli was observed in orbit. Body color change in response to the background color appeared to be delayed or slowed down. Response behavior to other stimuli showed little change as long as the animal maintained contact with a substrate. Once it left the surface, the floating frog could not control its movements so as to provide coordinated motility for locomotion and orientation. Adaptation to microgravity was observed in the landing behavior after jumping. Readaptation of the frogs to the Earth environment took place within a few hours after return. Postflight histological and biochemical analysis of organs and tissues showed some changes after the 8-day spaceflight. Weakening and density loss in vertebrae was noted. The beta-adrenoreceptor activity of the gastrocnemius was natriuretic decreased. Skin collagen and liver protein synthesis were lowered. The distribution of the atrial factor-like peptides in the brain was changed.

  12. Hyperspectral analysis of columbia spotted frog habitat

    Science.gov (United States)

    Shive, J.P.; Pilliod, D.S.; Peterson, C.R.

    2010-01-01

    Wildlife managers increasingly are using remotely sensed imagery to improve habitat delineations and sampling strategies. Advances in remote sensing technology, such as hyperspectral imagery, provide more information than previously was available with multispectral sensors. We evaluated accuracy of high-resolution hyperspectral image classifications to identify wetlands and wetland habitat features important for Columbia spotted frogs (Rana luteiventris) and compared the results to multispectral image classification and United States Geological Survey topographic maps. The study area spanned 3 lake basins in the Salmon River Mountains, Idaho, USA. Hyperspectral data were collected with an airborne sensor on 30 June 2002 and on 8 July 2006. A 12-year comprehensive ground survey of the study area for Columbia spotted frog reproduction served as validation for image classifications. Hyperspectral image classification accuracy of wetlands was high, with a producer's accuracy of 96 (44 wetlands) correctly classified with the 2002 data and 89 (41 wetlands) correctly classified with the 2006 data. We applied habitat-based rules to delineate breeding habitat from other wetlands, and successfully predicted 74 (14 wetlands) of known breeding wetlands for the Columbia spotted frog. Emergent sedge microhabitat classification showed promise for directly predicting Columbia spotted frog egg mass locations within a wetland by correctly identifying 72 (23 of 32) of known locations. Our study indicates hyperspectral imagery can be an effective tool for mapping spotted frog breeding habitat in the selected mountain basins. We conclude that this technique has potential for improving site selection for inventory and monitoring programs conducted across similar wetland habitat and can be a useful tool for delineating wildlife habitats. ?? 2010 The Wildlife Society.

  13. Large intestine bacterial flora of nonhibernating and hibernating leopard frogs (Rana pipiens).

    OpenAIRE

    Gossling, J; Loesche, W J; Nace, G W

    1982-01-01

    The bacteria in the large intestines of 10 northern leopard frogs (Rana pipiens) were enumerated and partially characterized. Four nonhibernating frogs were collected in the summer, four hibernating frogs were collected in the winter, and two frogs just emerged from hibernation were collected in the spring. All frogs had about 10(10) bacteria per g (wet weight) of intestinal contents and about 10(9) bacteria per g (wet weight) of mucosal scraping, although the counts from the winter frogs wer...

  14. The Mission of the Amazonian Universities in Economic Development and Environmental Preservation.

    Science.gov (United States)

    Lourenco, Jose Seixas

    The Association of Amazonian Universities (UNAMAZ) was created in September 1987 and is involved in a collective effort to find ways to promote the Amazonian region's nonpredatory development, recognizing its limitations and taking into account its potential. With deforestation taking place at ever-increasing speed, it has become necessary to…

  15. Estimating the global conservation status of more than 15,000 Amazonian tree species

    DEFF Research Database (Denmark)

    ter Steege, Hans; Pitman, Nigel C. A.; Killeen, Timothy J.

    2015-01-01

    Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree ...

  16. Response to Comment on "persistent effects of pre-Columbian plant domestication on Amazonian forest composition"

    NARCIS (Netherlands)

    Braga Junqueira, Andre; Levis, Carolina; Bongers, Frans; Peña-Claros, Marielos; Clement, Charles Roland; Costa, Flávia R.C.; Steege, Hans Ter

    2017-01-01

    McMichael et al. state that we overlooked the effects of post-Columbian human activities in shaping current floristic patterns in Amazonian forests. We formally show that post- Columbian human influences on Amazonian forests are indeed important, but they have played a smaller role when compared

  17. An uptake system for dietary alkaloids in poison frogs (Dendrobatidae).

    Science.gov (United States)

    Daly, J W; Secunda, S I; Garraffo, H M; Spande, T F; Wisnieski, A; Cover, J F

    1994-06-01

    The skin of poison frogs (Dendrobatidae) contains a wide variety of alkaloids that presumably serve a defensive role. These alkaloids persist for years in captivity, but are not present in captive-raised frogs. Alkaloids fed to poison frogs (Dendrobates, Phyllobates, Epipedobates) are readily accumulated into skin, where they remain for months. The process can be selective; an ant indolizidine is accumulated, while an ant pyrrolidine is not. Frogs (Colostethus) of the same family, which do not normally contain alkaloids, do not accumulate alkaloids. Such an alkaloid uptake system provides a means of maintaining skin alkaloids and suggests that some if not all such 'dendrobatid alkaloids' may have a dietary origin.

  18. Contributions of C3and C4plants to higher trophic levels in an Amazonian savanna.

    Science.gov (United States)

    Magnusson, William E; Carmozina de Araújo, M; Cintra, Renato; Lima, Albertina P; Martinelli, Luiz A; Sanaiotti, Tânia M; Vasconcelos, Heraldo L; Victoria, Reynaldo L

    1999-04-01

    We studied the energy flow from C 3 and C 4 plants to higher trophic levels in a central Amazonian savanna by comparing the carbon stable-isotope ratios of potential food plants to the isotope ratios of species of different consumer groups. All C 4 plants encountered in our study area were grasses and all C 3 plants were bushes, shrubs or vines. Differences in δ 13 C ratios among bushes (x¯ = -30.8, SD = 1.2), vines (x¯ = -30.7, SD = 0.46) and trees (x¯ = -29.7, SD = 1.5) were small. However the mean δ 13 C ratio of dicotyledonous plants (x¯ = -30.4, SD = 1.3) was much more negative than that of the most common grasses (x¯ = -13.4, SD = 0.27). The insect primary consumers had δ 13 C ratios which ranged from a mean of -29.5 (SD = 0.47) for the grasshopper Tropidacris collaris to a mean of -14.7 (SD = 0.56) for a termite (Nasutitermes sp.), a range similar to that of the vegetation. However, the common insectivorous and omnivorous vertebrates had intermediate values for δ 13 C, indicating that carbon from different autotrophic sources mixes rapidly as it moves up the food chain. Despite this mixing, the frogs and lizards generally had higher values of δ 13 C (x¯ = -21.7, SD = 1.6; x¯ = -21.9, SD = 1.8, respectively) than the birds (x¯ = -24.8, SD = 1.8) and the only species of mammal resident in the savanna (x¯ = -25.4), indicating that they are generally more dependent on, or more able to utilise, food chains based on C 4 grasses.

  19. Reducing outage times: a FROG perspective

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    In 1992, the Framatome Owners Group (FROG) was set up. It provides a forum for the members, who are all users of Framatome nuclear steam supply systems, to share and benefit from each others experience. Joint activities have been focused on safety and economic performance. Through effective control of outage duration, the average capability factor for the 60 plus nuclear units operated by the members rose from 74% in 1992 to 81.5% in 1993, while the average unplanned capability loss factor reduced from 9% to 3.5%. The specific measures now being taken by three FROG members to improve these results still further are described. The members concerned are Electrabel of Belgium, Electrite de France and the Korea Electric Power Co. (UK)

  20. Cellular mechanisms of nociception in the frog

    Czech Academy of Sciences Publication Activity Database

    Kuffler, D. P.; Lyfenko, Alla; Vyklický st., Ladislav; Vlachová, Viktorie

    2002-01-01

    Roč. 88, č. 4 (2002), s. 1843-1850 ISSN 0022-3077 R&D Projects: GA ČR GA305/00/1639; GA MŠk LN00B122 Grant - others:NATO(XX) Grant 977062 Institutional research plan: CEZ:AV0Z5011922 Keywords : cellular mechanisms of nociception * frog Subject RIV: FH - Neurology Impact factor: 3.743, year: 2002

  1. Yolk pigments of the Mexican leaf frog.

    Science.gov (United States)

    Marinetti, G V; Bagnara, J T

    1983-02-25

    Eggs of the Mexican leaf frog contain blue and yellow pigments identified as biliverdin and lutein, respectively. Both pigments are bound to proteins that occur in crystalline form in the yolk platelet. The major blue pigment is biliverdin IX alpha. The eggs vary in color from brilliant blue to pale yellow-green depending on the amount of each pigment. These pigments may provide protective coloration to the eggs.

  2. Environmental change and the carbon balance of Amazonian forests.

    Science.gov (United States)

    Aragão, Luiz E O C; Poulter, Benjamin; Barlow, Jos B; Anderson, Liana O; Malhi, Yadvinder; Saatchi, Sassan; Phillips, Oliver L; Gloor, Emanuel

    2014-11-01

    Extreme climatic events and land-use change are known to influence strongly the current carbon cycle of Amazonia, and have the potential to cause significant global climate impacts. This review intends to evaluate the effects of both climate and anthropogenic perturbations on the carbon balance of the Brazilian Amazon and to understand how they interact with each other. By analysing the outputs of the Intergovernmental Panel for Climate Change (IPCC) Assessment Report 4 (AR4) model ensemble, we demonstrate that Amazonian temperatures and water stress are both likely to increase over the 21st Century. Curbing deforestation in the Brazilian Amazon by 62% in 2010 relative to the 1990s mean decreased the Brazilian Amazon's deforestation contribution to global land use carbon emissions from 17% in the 1990s and early 2000s to 9% by 2010. Carbon sources in Amazonia are likely to be dominated by climatic impacts allied with forest fires (48.3% relative contribution) during extreme droughts. The current net carbon sink (net biome productivity, NBP) of +0.16 (ranging from +0.11 to +0.21) Pg C year(-1) in the Brazilian Amazon, equivalent to 13.3% of global carbon emissions from land-use change for 2008, can be negated or reversed during drought years [NBP = -0.06 (-0.31 to +0.01) Pg C year(-1) ]. Therefore, reducing forest fires, in addition to reducing deforestation, would be an important measure for minimizing future emissions. Conversely, doubling the current area of secondary forests and avoiding additional removal of primary forests would help the Amazonian gross forest sink to offset approximately 42% of global land-use change emissions. We conclude that a few strategic environmental policy measures are likely to strengthen the Amazonian net carbon sink with global implications. Moreover, these actions could increase the resilience of the net carbon sink to future increases in drought frequency. © 2014 The Authors. Biological Reviews © 2014 Cambridge Philosophical

  3. Environmental change and the carbon balance of Amazonian forests

    International Nuclear Information System (INIS)

    Aragao, Luiz E.O.C.; Poulter, Benjamin

    2014-01-01

    Extreme climatic events and land-use change are known to influence strongly the current carbon cycle of Amazonia, and have the potential to cause significant global climate impacts. This review intends to evaluate the effects of both climate and anthropogenic perturbations on the carbon balance of the Brazilian Amazon and to understand how they interact with each other. By analysing the outputs of the Intergovernmental Panel for Climate Change (IPCC) Assessment Report 4 (AR4) model ensemble, we demonstrate that Amazonian temperatures and water stress are both likely to increase over the 21. Century. Curbing deforestation in the Brazilian Amazon by 62% in 2010 relative to the 1990's mean decreased the Brazilian Amazon's deforestation contribution to global land use carbon emissions from 17% in the 1990's and early 2000's to 9% by 2010. Carbon sources in Amazonia are likely to be dominated by climatic impacts allied with forest fires (48.3% relative contribution) during extreme droughts. The current net carbon sink (net biome productivity, NBP) of +0.16 (ranging from +0.11 to +0.21) PgCyear-1 in the Brazilian Amazon, equivalent to 13.3% of global carbon emissions from land-use change for 2008, can be negated or reversed during drought years [NBP=-0.06 (-0.31 to +0.01) PgCyear -1 ]. Therefore, reducing forest fires, in addition to reducing deforestation, would be an important measure for minimizing future emissions. Conversely, doubling the current area of secondary forests and avoiding additional removal of primary forests would help the Amazonian gross forest sink to offset approximately 42% of global land-use change emissions. We conclude that a few strategic environmental policy measures are likely to strengthen the Amazonian net carbon sink with global implications. Moreover, these actions could increase the resilience of the net carbon sink to future increases in drought frequency. (authors)

  4. Medicinal plants of the Achuar (Jivaro) of Amazonian Ecuador: ethnobotanical survey and comparison with other Amazonian pharmacopoeias.

    Science.gov (United States)

    Giovannini, Peter

    2015-04-22

    This paper presents the first ethnobotanical survey conducted among the Achuar (Jivaro), indigenous people living in Amazonian Ecuador and Peru. The aims of this study are: (a) to present and discuss Achuar medicinal plant knowledge in the context of the epidemiology of this population (b) to compare the use of Achuar medicinal plants with the uses reported among the Shuar Jivaro and other Amazonian peoples. The author conducted field research in 9 indigenous villages in the region of Morona Santiago and Pastaza in Ecuador. Semi-structured interviews on local illnesses and herbal remedies were carried out with 82 informants and plant specimens were collected and later identified in Quito. A literature research was conducted on the medicinal species reported by Achuar people during this study. The most reported medicinal plants are species used by the Achuar to treat diarrhoea, parasites infection, fractures, wounds, and snakebites. Informants reported the use of 134 medicinal species for a total of 733 recorded use-reports. Of these 134 species, 44 are reported at least 3 times for one or more specific disease condition for a total of 56 uses. These species are considered a core kit of medicinal plants of the Achuar of Ecuador. Most of these medicinal species are widely used in the Amazon rainforest and in many other parts of Latin America. The author documented a core kit of 44 medicinal plants used among the Achuar of Ecuador and found that this core set of medicinal plants reflects local epidemiological concerns and the pharmacopoeias of the Shuar and other Amazonian groups. These findings suggest that inter-group diffusion of medicinal plant knowledge had a prominent role in the acquisition of current Achuar knowledge of medicinal plants. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  5. Assessment of frog meat utilisation in Ibadan, Oyo state, Nigeria ...

    African Journals Online (AJOL)

    Frogs are among the most threatened species of wildlife in IUCN red list. Its utilisation in Ibadan, a major depot in western Nigeria was therefore conducted with the aim of assessing the forms and trend of use; and amongst others, reasons for frog meat consumption. Data for the study were collected through questionnaire, ...

  6. Modeling potential river management conflicts between frogs and salmonids

    Science.gov (United States)

    Steven F. Railsback; Bret C. Harvey; Sarah J. Kupferberg; Margaret M. Lang; Scott McBain; Hart H. Welsh

    2016-01-01

    Management of regulated rivers for yellow-legged frogs (Rana boylii) and salmonids exemplifies potential conflicts among species adapted to different parts of the natural flow and temperature regimes. Yellow-legged frogs oviposit in rivers in spring and depend on declining flows and warming temperatures for egg and tadpole survival and growth,...

  7. Using a Phototransduction System to Monitor the Isolated Frog Heart

    Science.gov (United States)

    Stephens, Philip J.

    2015-01-01

    A simple and inexpensive method of monitoring the movement of an isolated frog heart provides comparable results to those obtained with a force transducer. A commercially available photoresistor is integrated into a Wheatstone bridge circuit, and the output signal is interfaced directly with a recording device. An excised, beating frog heart is…

  8. Coleman Revisited: School Segregation, Peers, and Frog Ponds

    Science.gov (United States)

    Goldsmith, Pat Rubio

    2011-01-01

    Students from minority segregated schools tend to achieve and attain less than similar students from White segregated schools. This study examines whether peer effects can explain this relationship using normative models and frog-pond models. Normative models (where peers become alike) suggest that minority schoolmates are a liability. Frog-pond…

  9. Neuroendocrine regulation of frog adrenocortical cells by neurotensin

    NARCIS (Netherlands)

    Sicard, F.; D, D.E.G.; Gras, M.; Leprince, J.; Conlon, J.M.; Roubos, E.W.; Vaudry, H.; Delarue, C.

    2005-01-01

    We previously characterized the primary structure of neurotensin (NT) from an extract of the intestine of the frog Rana esculenta. In this study, we provide evidence for the involvement of NT in the neurocrine regulation of the secretory activity of frog adrenocortical cells. Immunohistochemical

  10. Foothill yellow-legged frog conservation assessment in California

    Science.gov (United States)

    Marc P. Hayes; Clara A. Wheeler; Amy J. Lind; Gregory A. Green; Diane C. Macfarlane

    2016-01-01

    The foothill yellow-legged frog (Rana boylii) is a stream-breeding amphibian that has experienced significant population declines over a large portion of its historical range. This frog is nearing extirpation in much of the Sierra Nevada region where existing populations are sparse. Water development and diversions are likely to be the primary...

  11. Foraging behaviour in tadpoles of the bronze frog Rana temporalis ...

    Indian Academy of Sciences (India)

    Unknown

    Amphibia; anura; bronze frog; foraging strategy; frog; ideal free distribution; Rana temporalis; tadpoles ... less competition. Then on, both patches will be occupied. The expected mean gain will thus be the same across the food patches. Evidence supporting the IFD ... tat A or B. However the next forager would benefit by.

  12. Amazonian Buriti oil: chemical characterization and antioxidant potential

    Energy Technology Data Exchange (ETDEWEB)

    Speranza, P.; Oliveira Falcao, A. de; Alves Macedo, J.; Silva, L.H.M. da; Rodrigues, A.M. da C.; Alves Macedo, G.

    2016-07-01

    Buriti oil is an example of an Amazonian palm oil of economic importance. The local population uses this oil for the prevention and treatment of different diseases; however, there are few studies in the literature that evaluate its properties. In this study, detailed chemical and antioxidant properties of Buriti oil were determined. The predominant fatty acid was oleic acid (65.6%) and the main triacylglycerol classes were tri-unsaturated (50.0%) and di-unsaturated-mono-saturated(39.3%) triacylglycerols. The positional distribution of the classes of fatty acids on the triacylglycerol backbone indicated a saturated and unsaturated fatty acid relationship similar in the three-triacylglycerol positions. All tocopherol isomers were present, with a total content of 2364.1 mg·kg−1. α-tocopherol constitutes 48% of the total tocopherol content, followed by γ- tocopherol (45%). Total phenolic (107.0 mg gallic acid equivalent·g−1 oil) and β-carotene (781.6 mg·kg−1) were particularly high in this oil. The highest antioxidant activity against the free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) was obtained at an oil concentration of 50 mg·mL−1 (73.15%). The antioxidant activity evaluated by the Oxygen Radical Absorbance Capacity (ORAC) was 95.3 μmol Trolox equivalent·g−1 oil. These results serve to present Buriti oil as an Amazonian resource for cosmetic, food and pharmaceuticals purposes. (Author)

  13. Sustainable development, social organization and environment in the Amazonian Area

    International Nuclear Information System (INIS)

    Vieco, Juan Jose

    2001-01-01

    The effects of the development on the environment and the culture in regions like the Amazonian are one of the most dramatic examples that can be in what refers to the physical disappearance of numerous cultures, as well as of their integration to the national society and their rising loss of cultural identity and the devastating consequences that have had the development politicians on the different Amazon ecosystems. The construction of a sustainable development for the region has to evaluate the different societies that have existed and they exist as for the use, handling and exploitation of the natural resources. This paper will be approached this problem in three Amazon societies: the cacique territory, the tribal societies and the societies in formation in the colonization regions. It will be done an analysis and a critic of the development concept and of the consequences that it has had their application so much in the indigenous towns as in the Amazon ecosystems, as well as their relationship with the current characterization of the Amazonian area

  14. Amazonian functional diversity from forest canopy chemical assembly.

    Science.gov (United States)

    Asner, Gregory P; Martin, Roberta E; Tupayachi, Raul; Anderson, Christopher B; Sinca, Felipe; Carranza-Jiménez, Loreli; Martinez, Paola

    2014-04-15

    Patterns of tropical forest functional diversity express processes of ecological assembly at multiple geographic scales and aid in predicting ecological responses to environmental change. Tree canopy chemistry underpins forest functional diversity, but the interactive role of phylogeny and environment in determining the chemical traits of tropical trees is poorly known. Collecting and analyzing foliage in 2,420 canopy tree species across 19 forests in the western Amazon, we discovered (i) systematic, community-scale shifts in average canopy chemical traits along gradients of elevation and soil fertility; (ii) strong phylogenetic partitioning of structural and defense chemicals within communities independent of variation in environmental conditions; and (iii) strong environmental control on foliar phosphorus and calcium, the two rock-derived elements limiting CO2 uptake in tropical forests. These findings indicate that the chemical diversity of western Amazonian forests occurs in a regionally nested mosaic driven by long-term chemical trait adjustment of communities to large-scale environmental filters, particularly soils and climate, and is supported by phylogenetic divergence of traits essential to foliar survival under varying environmental conditions. Geographically nested patterns of forest canopy chemical traits will play a role in determining the response and functional rearrangement of western Amazonian ecosystems to changing land use and climate.

  15. Pterygium: prevalence and severity in an Amazonian ophthalmic setting, Brazil

    Directory of Open Access Journals (Sweden)

    Sophie Joanna Coutts

    2012-12-01

    Full Text Available OBJECTIVE: This is a cross sectional ophthalmic clinic-based study to estimate the prevalence and severity of pterygium in a selected population in the Amazon Basin, Brazil. METHODS: The study included 225 subjects above 20 years age from three different places of residence of Manaus city (group 1, n=89, river based communities (group 2, n= 116 and indigenous rainforest inhabitants (group 3, n=20. Pterygia was graded 1-4 by torch examination and gender, age and occupation determined. RESULTS: were assessed to have pterygia (grades 2-4 117 people; 52% against 108 control subjects with bilateral disease in 43% of subjects. Prevalence of grades 2-4 increased from 36% in group 1 to 62.5 % in group 2 and 75% in group 3. Of these subjects the percentage with outdoor professions increased across the groups from 31.2% to 67.1 % and 70% respectively. Also subjects of group 2 who worked largely outdoors, showed increasing pterygia severity, from grades 2 at 57% (p=0.0002, grade 3 at 93.3% (p,0.0001 to grade 4 at 100% (p=0.0004 CONCLUSION: Amazonian communities have a high prevalence of pterygia, which correlates to greater outdoor occupation and sun exposure. This study agrees with previous worldwide reports and it is the first study to compare the prevalence of pterygium in rural and urban living in Amazonian in Brazil. This study highlights the public health significance and gross need for intervention studies.

  16. Amazonian indigenous settlement and local development in Pastaza, Ecuador

    Directory of Open Access Journals (Sweden)

    Ruth I. Arias-Gutiérrez

    2016-07-01

    Full Text Available In six Amazonian indigenous communities that call to their selves as membership of nación Kichwa, located in Pastaza province, in Ecuador, it is analyzed the process of inhabitation, population characteristics, how much the territory is enough for food requirements for the indigenous families, and their use of land, to determine important factors to improve strategies for local sustainable development. It is considered important because Ecuador has constitutional protection for plural ethnicity and it is looking for improving a new productivity matrix that let down extraction and contamination and raise another matrix based on knowledge and richness from natural renewable resources. Survey used statistics information, qualitative analysis around reality in process, participant research, documentary analysis, oral history and surveys to leadership and family`s chiefs. Results confirm that communities hold standing their identity and knowledge systems of the Amazonian environment, whose conservation they need. Those are factors to be included in local development strategies that let people become safe from effects of extractives activities that are dangerous for culture and environment, in the geographic and biological diversity of the high Ecuadorian Amazonia.

  17. Spatial trends in leaf size of Amazonian rainforest trees

    Directory of Open Access Journals (Sweden)

    A. C. M. Malhado

    2009-08-01

    Full Text Available Leaf size influences many aspects of tree function such as rates of transpiration and photosynthesis and, consequently, often varies in a predictable way in response to environmental gradients. The recent development of pan-Amazonian databases based on permanent botanical plots has now made it possible to assess trends in leaf size across environmental gradients in Amazonia. Previous plot-based studies have shown that the community structure of Amazonian trees breaks down into at least two major ecological gradients corresponding with variations in soil fertility (decreasing from southwest to northeast and length of the dry season (increasing from northwest to south and east. Here we describe the geographic distribution of leaf size categories based on 121 plots distributed across eight South American countries. We find that the Amazon forest is predominantly populated by tree species and individuals in the mesophyll size class (20.25–182.25 cm2. The geographic distribution of species and individuals with large leaves (>20.25 cm2 is complex but is generally characterized by a higher proportion of such trees in the northwest of the region. Spatially corrected regressions reveal weak correlations between the proportion of large-leaved species and metrics of water availability. We also find a significant negative relationship between leaf size and wood density.

  18. Tongue adhesion in the horned frog Ceratophrys sp.

    Science.gov (United States)

    Kleinteich, Thomas; Gorb, Stanislav N.

    2014-06-01

    Frogs are well-known to capture elusive prey with their protrusible and adhesive tongues. However, the adhesive performance of frog tongues and the mechanism of the contact formation with the prey item remain unknown. Here we measured for the first time adhesive forces and tongue contact areas in living individuals of a horned frog (Ceratophrys sp.) against glass. We found that Ceratophrys sp. generates adhesive forces well beyond its own body weight. Surprisingly, we found that the tongues adhered stronger in feeding trials in which the coverage of the tongue contact area with mucus was relatively low. Thus, besides the presence of mucus, other features of the frog tongue (surface profile, material properties) are important to generate sufficient adhesive forces. Overall, the experimental data shows that frog tongues can be best compared to pressure sensitive adhesives (PSAs) that are of common technical use as adhesive tapes or labels.

  19. Pathogenesis of Frog Virus 3 ( Ranavirus, Iridoviridae) Infection in Wood Frogs ( Rana sylvatica).

    Science.gov (United States)

    Forzán, M J; Jones, K M; Ariel, E; Whittington, R J; Wood, J; Markham, R J Frederick; Daoust, P-Y

    2017-05-01

    Wood frogs ( Rana sylvatica) are highly susceptible to infection with Frog virus 3 (FV3, Ranavirus, Iridoviridae), a cause of mass mortality in wild populations. To elucidate the pathogenesis of FV3 infection in wood frogs, 40 wild-caught adults were acclimated to captivity, inoculated orally with a fatal dose of 10 4.43 pfu/frog, and euthanized at 0.25, 0.5, 1, 2, 4, 9, and 14 days postinfection (dpi). Mild lesions occurred sporadically in the skin (petechiae) and bone marrow (necrosis) during the first 2 dpi. Severe lesions occurred 1 to 2 weeks postinfection and consisted of necrosis of medullary and extramedullary hematopoietic tissue, lymphoid tissue in spleen and throughout the body, and epithelium of skin, mucosae, and renal tubules. Viral DNA was first detected (polymerase chain reaction) in liver at 4 dpi; by dpi 9 and 14, all viscera tested (liver, kidney, and spleen), skin, and feces were positive. Immunohistochemistry (IHC) first detected viral antigen in small areas devoid of histologic lesions in the oral mucosa, lung, and colon at 4 dpi; by 9 and 14 dpi, IHC labeling of viral antigen associated with necrosis was found in multiple tissues. Based on IHC staining intensity and lesion severity, the skin, oral, and gastrointestinal epithelium and renal tubular epithelium were important sites of viral replication and shedding, suggesting that direct contact (skin) and fecal-oral contamination are effective routes of transmission and that skin tissue, oral, and cloacal swabs may be appropriate antemortem diagnostic samples in late stages of disease (>1 week postinfection) but poor samples to detect infection in clinically healthy frogs.

  20. The response of Rana muscosa, the mountain yellow-legged frog, to short distance translocations.

    Science.gov (United States)

    K. R. Matthews

    2003-01-01

    ABSTRACT.—To determine the response of Mountain Yellow-Legged Frogs to short distance translocations, I placed transmitters on 20 adult frogs and moved them short distances from 144–630 m and monitored their responses for up to 30 days. Of the 20 translocated frogs, seven frogs returned to their original capture site, four frogs moved in the direction of their capture...

  1. The Observation of Frog Species at State University of Malang as a Preliminary Effort on Frog Conservation

    Directory of Open Access Journals (Sweden)

    Dian Ratri Wulandari

    2013-04-01

    Full Text Available Frog is an amphibian which is widely spread around the world. Indonesia houses 450 species which represent 11% of frog species in the world. In Java Island alone, there live 42 species of frogs and toads. Frogs can be used as an environment indicator in that the presence of frog in a particular place indicates that the place stays natural and unpolluted. The 1st Campus of State University of Malang, which is located in the heart of Malang District, has been developing rapidly currently. Thus, it requires the construction of new various facilities to support its huge activities. Extensive construction can be destructive even damaging to the habitat of frog, which potentially threats the frog’s life, if it does not take the environmental impact into careful consideration. This study is aimed to identify the species of frog which survives at State University of Malang with, particularly the frog species found in 1995. Species identification was conducted by observing the morphological character. This study found that there were four species with three species remained survived in 1995; those were Duttaphrynus melanostictus, Polypedates leucomystax, and Kaloula baleta; and one new species called Rana chalconota. This study also revealed that there were four species which were extinct; those were Fejervarya cancrivora, Fejervarya limnocharis, Ingerophrynus biporcatus, and Occidoziga lima. This situation shows the decreasing amount of species from 7 to 4 within the last 17 years. This result indicates that there is a serious environmental degradation which causes the losing of frog habitats. Further research is needed to study the ecological condition changing in order to save the frog species.

  2. Effects of increasing temperature and, CO2 on quality of litter, shredders, and microorganisms in Amazonian aquatic systems

    OpenAIRE

    Martins, Renato Tavares; Rezende, Renan de Souza; Gonçalves Júnior, José Francisco; Lopes, Aline; Piedade, Maria Teresa Fernandez; Cavalcante, Heloide de Lima; Hamada, Neusa

    2017-01-01

    Climate change may affect the chemical composition of riparian leaf litter and, aquatic organisms and, consequently, leaf breakdown. We evaluated the effects of different scenarios combining increased temperature and carbon dioxide (CO2) on leaf detritus of Hevea spruceana (Benth) Müll. and decomposers (insect shredders and microorganisms). We hypothesized that simulated climate change (warming and elevated CO2) would: i) decrease leaf-litter quality, ii) decrease survival and leaf breakdown ...

  3. Composition and diversity of northwestern Amazonian rainforests in a geoecological context

    NARCIS (Netherlands)

    Duivenvoorden, J.F.; Duque, A.J.; Hoorn, C.; Wesselingh, F.P.

    2010-01-01

    The northwestern Amazonian landscape includes most of the representative landscape units that characterize Amazonia, and for this reason it constitutes an excellent place to investigate relationships between the abiotic environment (geology, geomorphology, soils) and biodiversity. In this review we

  4. Pre-LBA Anglo-Brazilian Amazonian Climate Observation Study (ABRACOS) Data

    Data.gov (United States)

    National Aeronautics and Space Administration — The data set presents the principal data from the Anglo-BRazilian Amazonian Climate Observation Study (ABRACOS) (Gash et al. 1996) and provides quality controlled...

  5. Pre-LBA Anglo-Brazilian Amazonian Climate Observation Study (ABRACOS) Data

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: The data set presents the principal data from the Anglo-BRazilian Amazonian Climate Observation Study (ABRACOS) (Gash et al. 1996) and provides quality...

  6. LBA-ECO LC-09 Natural, Infrastructure, and Boundary Features, Amazonian Sites, Brazil

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set includes 16 zipped archives of shapefiles of cities, rivers and streams, roads, and study area boundaries of several Amazonian study sites:...

  7. LBA-ECO LC-09 Natural, Infrastructure, and Boundary Features, Amazonian Sites, Brazil

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes 16 zipped archives of shapefiles of cities, rivers and streams, roads, and study area boundaries of several Amazonian study sites: Altamira,...

  8. Unihemispheric slow-wave sleep in the Amazonian dolphin, Inia geoffrensis.

    Science.gov (United States)

    Mukhametov, L M

    1987-08-18

    An electroencephalographic study of sleep in Amazonian dolphins, Inia geoffrensis, revealed that unihemispheric slow-wave sleep is the dominant sleep type in this species, as in the other two dolphin species that were studied earlier.

  9. Food Plants Eaten by Amazonian Manatees (Trichechus inunguis, Mammalia : Sirenia

    Directory of Open Access Journals (Sweden)

    Ioni G. Colares

    2002-03-01

    Full Text Available To determine the feeding habits of the Amazonian manatee Trichechus inunguis in some Central Amazonian rivers and lakes, we compared plant epidermis found in the stomach contents and/or faeces of animals with a reference collection of plants present in the studied areas. Twenty five samples from digestive tracts of animals found dead and 25 faeces samples found floating were analyzed. From these samples, 24 aquatic macrophytes were identified. The Gramineae family was identified in 96% of the samples, Paspalum repens and Echinochloa polystachya being the most abundant in the samples. The second most frequent family was the Pontederiaceae primarily Eichhornia crassipes. During the high water period, the animals showed a more selective diet (eight identified species. In the low water period, when food was more scarce, the animals showed a larger diversity of species in their diet (21 species of plants. Differences in the diet among the two studied areas reflected the physiographics characteristics of the region. Amazonian manatees fed mostly on emergent plants.Para determinar o hábito alimentar do peixe-boi da Amazonia em alguns rios e lagos da Amazonia Central, nós comparamos as epidermes de plantas encontradas nos conteúdos alimentares e/ou fezes de animais com uma coleção de referência de epidermes de plantas presentes nas áreas de estudo. Foram analisadas 25 amostras de trato digestivo de animais encontrados mortos e 25 amostras de fezes . A familia Gramineae foi encontrada em 96% das amostras, com maior ocorrência das espécies Paspalum repens e Echinochloa polystachya. A segunda familia mais freqüente foi Pontederiaceae sendo Eichhornia crassipes a espécie predominante. Durante o período de água cheia, os animais apresentaram uma dieta mais seletiva (oito espécies identificadas. Já na água baixa, com menor oferta de alimentos, os animais apresentam uma maior diversidade de espécies em sua dieta (21 espécies de plantas

  10. Geological control of floristic composition in Amazonian forests.

    Science.gov (United States)

    Higgins, Mark A; Ruokolainen, Kalle; Tuomisto, Hanna; Llerena, Nelly; Cardenas, Glenda; Phillips, Oliver L; Vásquez, Rodolfo; Räsänen, Matti

    2011-11-01

    AIM: Conservation and land-use planning require accurate maps of patterns in species composition and an understanding of the factors that control them. Substantial doubt exists, however, about the existence and determinants of large-area floristic divisions in Amazonia. Here we ask whether Amazonian forests are partitioned into broad-scale floristic units on the basis of geological formations and their edaphic properties. LOCATION: Western and central Amazonia. METHODS: We used Landsat imagery and Shuttle Radar Topography Mission (SRTM) digital elevation data to identify a possible floristic and geological discontinuity of over 300 km in northern Peru. We then used plant inventories and soil sampling to document changes in species composition and soil properties across this boundary. Data were obtained from 138 sites distributed along more than 450 km of road and river. On the basis of our findings, we used broad-scale Landsat and SRTM mosaics to identify similar patterns across western and central Amazonia. RESULTS: The discontinuity identified in Landsat and SRTM data corresponded to a 15-fold change in soil cation concentrations and an almost total change in plant species composition. This discontinuity appears to be caused by the widespread removal of cation-poor surface sediments by river incision to expose cation-rich sediments beneath. Examination of broad-scale Landsat and SRTM mosaics indicated that equivalent processes have generated a north-south discontinuity of over 1500 km in western Brazil. Due to similarities with our study area, we suggest that this discontinuity represents a chemical and ecological limit between western and central Amazonia. MAIN CONCLUSIONS: Our findings suggest that Amazonian forests are partitioned into large-area units on the basis of geological formations and their edaphic properties. The evolution of these units through geological time may provide a general mechanism for biotic diversification in Amazonia. These

  11. Experimental transmission of cutaneous chytridiomycosis in dendrobatid frogs.

    Science.gov (United States)

    Nichols, D K; Lamirande, E W; Pessier, A P; Longcore, J E

    2001-01-01

    In a series of three experiments during March-October, 1998, two species of captive-bred poison dart frogs (Dendrobates tinctorius and D. auratus) were exposed to Batrachochytrium dendrobatidis, a recently-described chytridiomycete fungus (chytrid) that was originally isolated from a blue poison dart frog (D. azureus). All frogs exposed to the chytrids developed a fatal skin disease, whereas none of the control frogs developed skin lesions. The most consistent clinical sign in chytrid-exposed frogs was excessive shedding of skin. Gross lesions were subtle, usually affected the legs and ventrum, and consisted of mild skin thickening and discoloration. Microscopic examination of shed skin pieces and/or skin imprints demonstrated the presence of chytrids and was used for ante mortem and post mortem confirmation of chytrid infection. Histologically, there was epidermal hyperkeratosis, hyperplasia, and hypertrophy associated with low to moderate numbers of chytrids in the keratinized layers. These experiments demonstrated that Batrachochytrium dendrobatidis can be a fatal pathogen in poison dart frogs. The experimentally-induced disease in these frogs resembled cases of cutaneous chytridiomycosis that have recently been described in several other species of captive and wild amphibians.

  12. The gastrocoel roof plate in embryos of different frogs.

    Science.gov (United States)

    Sáenz-Ponce, Natalia; Santillana-Ortiz, Juan-Diego; del Pino, Eugenia M

    2012-02-01

    The morphology of the gastrocoel roof plate and the presence of cilia in this structure were examined in embryos of four species of frogs. Embryos of Ceratophrys stolzmanni (Ceratophryidae) and Engystomops randi (Leiuperidae) develop rapidly, provide comparison for the analysis of gastrocoel roof plate development in the slow-developing embryos of Epipedobates machalilla (Dendrobatidae) and Gastrotheca riobambae (Hemiphractidae). Embryos of the analyzed frogs develop from eggs of different sizes, and display different reproductive and developmental strategies. In particular, dorsal convergence and extension and archenteron elongation begin during gastrulation in embryos of rapidly developing frogs, as in Xenopus laevis. In contrast, cells that involute during gastrulation are stored in the large circumblastoporal collar that develops around the closed blastopore in embryos of slow-developing frogs. Dorsal convergence and extension only start after blastopore closure in slow-developing frog embryos. However, in the neurulae, a gastrocoel roof plate develops, despite the accumulation of superficial mesodermal cells in the circumblastoporal collar. Embryos of all four species develop a ciliated gastrocoel roof plate at the beginning of neurulation. Accordingly, fluid-flow across the gastrocoel roof plate is likely the mechanism of left-right asymmetry patterning in these frogs, as in X. laevis and other vertebrates. A ciliated gastrocoel roof plate, with a likely origin as superficial mesoderm, is conserved in frogs belonging to four different families and with different modes of gastrulation. Copyright © 2011 International Society of Differentiation. Published by Elsevier B.V. All rights reserved.

  13. Landing on branches in the frog Trachycephalus resinifictrix (Anura: Hylidae).

    Science.gov (United States)

    Bijma, Nienke N; Gorb, Stanislav N; Kleinteich, Thomas

    2016-04-01

    Frogs (Lissamphibia: Anura) are famous for their saltatory or hopping locomotion, which is related to numerous anatomical specialisations that are characteristic for the group. However, while the biomechanics of take-off in frogs have been studied in detail, much less is known on how frogs land after a jump. Besides terrestrial and aquatic species, several lineages of frogs adopted an arboreal lifestyle and especially the biomechanics of landing on challenging, small, and unpredictable substrates, such as leaves or branches, are virtually unknown. Here we studied the landing kinematics of the arboreal frog Trachycephalus resinifictrix (Hylidae) on a wooden stick that was used to mimic a small tree branch. We observed two different landing behaviours: (1) landing on the abdomen and (2) attachment with the toes of either the forelimb or the hindlimb. In the latter case, the frogs performed a cartwheel around the stick, while they were only attached by their adhesive toe pads. We estimated the forces that act on the toes during this behaviour to be up to fourteen times the body weight of the animals. This behaviour demonstrates the remarkable adhesive capabilities of the toe pads and the body control of the frogs.

  14. Estimating the global conservation status of more than 15,000 Amazonian tree species

    OpenAIRE

    ter Steege, H.; et al., [Unknown; Duivenvoorden, J.F.

    2015-01-01

    Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened ...

  15. A marvelous new glassfrog (Centrolenidae, Hyalinobatrachium) from Amazonian Ecuador

    Science.gov (United States)

    Guayasamin, Juan M.; Cisneros-Heredia, Diego F.; Maynard, Ross J.; Lynch, Ryan L.; Culebras, Jaime; Hamilton, Paul S.

    2017-01-01

    Abstract Hyalinobatrachium is a behaviorally and morphologically conserved genus of Neotropical anurans, with several pending taxonomic problems. Using morphology, vocalizations, and DNA, a new species from the Amazonian lowlands of Ecuador is described and illustrated. The new species, Hyalinobatrachium yaku sp. n., is differentiated from all other congenerics by having small, middorsal, dark green spots on the head and dorsum, a transparent pericardium, and a tonal call that lasts 0.27–0.4 s, with a dominant frequency of 5219.3–5329.6 Hz. Also, a mitochondrial phylogeny for the genus is presented that contains the new species, which is inferred as sister to H. pellucidum. Conservation threats to H. yaku sp. n. include habitat destruction and/or pollution mainly because of oil and mining activities. PMID:28769670

  16. Influence of digestive morphology on resource partitioning in Amazonian ungulates.

    Science.gov (United States)

    Bodmer, Richard E

    1991-01-01

    Resource partitioning of diet and habitat use was studied in the entire Amazonian ungulate community of Northeastern Peru, which comprises the red brocket deer (Mazama americana), grey brocket deer (M. gouazoubira), collared peccary (Tayassu tajacu), white-lipped peccary (T. pecari), and lowland tapir (Tapirus terrestris). Each ungulate species partitioned at least one type of resource from every other species. Digestive morphology had a greater influence on resource partitioning of diet than body size. Neither digestive morphology nor body size were related to segregation of habitats. However, species with similar diets partitioned habitats, whereas species with different diets often used the same type of forest. Increases in habitat breadth of ungulates were positively correlated with increases in dietary breadth.

  17. The sustainability search in the Amazonian productive systems

    International Nuclear Information System (INIS)

    Wood, Allan A

    2001-01-01

    Historically the society and the state have a little attention to the Amazonian area and this it continues being one of the regions but marginal of the country. The countries that possess Amazon territory have spread to neglect those lands so far away and unknown. In spite of their margination, the region goes getting paid every time but importance in the nation and the world. The information that it keeps their diversity biotic and cultural it has international recognition; economically it has considerable reservations of minerals, wood and fishes, which are extracted to supply the national and international markets. Politically the region is mentioned by the social conflict and the colonization that it fronts, it also has the only frontiers with Brazil and Peru, in the future, will be built the marginal highway of the forest; connecting to Ecuador with Colombia and Venezuela, opening significant spaces for the trade and the international integration

  18. Active control of ultrasonic hearing in frogs

    Science.gov (United States)

    Gridi-Papp, Marcos; Feng, Albert S.; Shen, Jun-Xian; Yu, Zu-Lin; Rosowski, John J.; Narins, Peter M.

    2008-01-01

    Vertebrates can modulate the sound levels entering their inner ears in the face of intense external sound or during their own vocalizations. Middle ear muscle contractions restrain the motion of the middle ear ossicles, attenuating the transmission of low-frequency sound and thereby protecting the hair cells in the inner ear. Here we show that the Chinese concave-eared torrent frog, Odorrana tormota, can tune its ears dynamically by closing its normally open Eustachian tubes. Contrary to the belief that the middle ear in frogs permanently communicates with the mouth, O. tormota can close this connection by contraction of the submaxillary and petrohyoid muscles, drastically reducing the air volume behind the eardrums. Mathematical modeling and laser Doppler vibrometry revealed that the reduction of this air volume increases the middle ear impedance, resulting in an up to 20 dB gain in eardrum vibration at high frequencies (10–32 kHz) and 26 dB attenuation at low frequencies (3–10 kHz). Eustachian tube closure was observed in the field during calling and swallowing. Besides a potential role in protecting the inner ear from intense low-frequency sound and high buccal air pressure during calling, this previously unrecognized vertebrate mechanism may unmask the high-frequency calls of this species from the low-frequency stream noise which dominates the environment. This mechanism also protects the thin tympanic membranes from injury during swallowing of live arthropod prey. PMID:18658240

  19. Autometallographic tracing of mercury in frog liver

    International Nuclear Information System (INIS)

    Loumbourdis, N.S.; Danscher, G.

    2004-01-01

    The distribution of mercury in the liver of the frog Rana ridibunda with the autometallographic method was investigated. The mercury specific autometallographic (HgS/Se AMG ) technique is a sensitive histochemical approach for tracing mercury in tissues from mercury-exposed organisms. Mercury accumulates in vivo as mercury sulphur/mercury selenium nanocrystals that can be silver-enhanced. Thus, only a fraction of the Hg can be visualized. Six animals were exposed for one day and another group of six animals for 6 days in 1 ppm mercury (as HgCI 2 ) dissolved in fresh water. A third group of six animals, served as controls, were sacrificed the day of arrival at the laboratory. First, mercury appears in the blood plasma and erythrocytes. Next, mercury moves to hepatocytes and in the apical part of the cells, that facing bile canaliculi. In a next step, mercury appears in the endothelial and Kupffer cells. It seems likely that, the mercury of hepatocytes moves through bile canaliculi to the gut, most probably bound to glutathione and/or other similar ligands. Most probably, the endothelial and Kupffer cells comprise the first line of defense against metal toxicity. - Frogs can be good bioindicators of mercury

  20. Drought responses of flood-tolerant trees in Amazonian floodplains.

    Science.gov (United States)

    Parolin, Pia; Lucas, Christine; Piedade, Maria Teresa F; Wittmann, Florian

    2010-01-01

    Flood-tolerant tree species of the Amazonian floodplain forests are subjected to an annual dry period of variable severity imposed when low river-water levels coincide with minimal precipitation. Although the responses of these species to flooding have been examined extensively, their responses to drought, in terms of phenology, growth and physiology, have been neglected hitherto, although some information is found in publications that focus on flooding. The present review examines the dry phase of the annual flooding cycle. It consolidates existing knowledge regarding responses to drought among adult trees and seedlings of many Amazonian floodplain species. Flood-tolerant species display variable physiological responses to dry periods and drought that indicate desiccation avoidance, such as reduced photosynthetic activity and reduced root respiration. However, tolerance and avoidance strategies for drought vary markedly among species. Drought can substantially decrease growth, biomass and photosynthetic activity among seedlings in field and laboratory studies. When compared with the responses to flooding, drought can impose higher seedling mortality and slower growth rates, especially among evergreen species. Results indicate that tolerance and avoidance strategies for drought vary markedly between species. Both seedling recruitment and photosynthetic activity are affected by drought, For many species, the effects of drought can be as important as flooding for survival and growth, particularly at the seedling phase of establishment, ultimately influencing species composition. In the context of climate change and predicted decreases in precipitation in the Amazon Basin, the effects of drought on plant physiology and species distribution in tropical floodplain forest ecosystems should not be overlooked.

  1. Complete Genome Sequence of Frog virus 3, Isolated from a Strawberry Poison Frog (Oophaga pumilio) Imported from Nicaragua into the Netherlands

    NARCIS (Netherlands)

    Saucedo, Bernardo; Hughes, Joseph; van Beurden, Steven J; Suárez, Nicolás M; Haenen, Olga L M; Voorbergen-Laarman, Michal A; Gröne, Andrea; Kik, Marja J L

    2017-01-01

    Frog virus 3 was isolated from a strawberry poison frog (Oophaga pumilio) imported from Nicaragua via Germany to the Netherlands, and its complete genome sequence was determined. Frog virus 3 isolate Op/2015/Netherlands/UU3150324001 is 107,183 bp long and has a nucleotide similarity of 98.26% to the

  2. Complete genome sequence of frog virus 3, isolated from a strawberry poison frog (Oophaga pumilio) imported from nicaragua into the Netherlands

    NARCIS (Netherlands)

    Saucedo, Bernardo; Hughes, Joseph; Beurden, van Steven J.; Suárez, Nicolás M.; Haenen, Olga L.M.; Voorbergen-Laarman, Michal; Gröne, Andrea; Kika, Marja J.L.

    2017-01-01

    Frog virus 3 was isolated from a strawberry poison frog (Oophaga pumilio) imported from Nicaragua via Germany to the Netherlands, and its complete genome sequence was determined. Frog virus 3 isolate Op/2015/Netherlands/UU3150324001 is 107,183 bp long and has a nucleotide similarity of 98.26% to the

  3. Frogs host faecal bacteria typically associated with humans.

    Science.gov (United States)

    Gibb, Karen; Schobben, Xavier; Christian, Keith

    2017-07-01

    Tree frogs commonly access drinking water tanks; this may have human health implications. Although amphibians might not be expected to host mammalian faecal indicator bacteria (FIB), it is possible that they may have human FIB on their skin after exposure to human waste. We collected faeces and skin wash from green tree frogs (Litoria caerulea) from a natural environment, a suburban site, and a suburban site near a creek occasionally contaminated with sewage effluent. We used molecular techniques to test for FIB that are routinely used to indicate human faecal contamination. Enterococci colonies were isolated from both faecal and skin wash samples, and specific markers (Enterococcus faecium and Bacteroides thetaiotaomicron) were found in frog faeces, demonstrating that these markers are not human- or mammalian-specific. Bacteroides thetaiotaomicron was detected in frogs from both natural and urban sites, but E. faecium was only associated with the sewage impacted site.

  4. 10 years of activities for the Framatome Owners Group (FROG)

    International Nuclear Information System (INIS)

    Oullion, J.; Namy, Ph.

    2001-01-01

    FROG (Framatome owners group) was created in 1991 by 5 electricity producers Electrabel (Belgium), EDF (France), ESKOM (South-Africa), GNPJVC (Daya bay China) and KEPCO (South-Korea), since then 2 other members joined the group Vattenfall (Sweden) and LANPC ( Ling-Ao China). All the members agree to share their experience in operating nuclear reactors designed by Framatome, FROG members represent more than 80 nuclear units. FROG wants to promote the exchange of information between its members in order to improve performances in a broad sense (safety, techniques, costs and management). The FROG committee opened its 20. meeting last year in Lyon (France), among the different topics that were discussed we have: -) a review of the main events that occurred in nuclear power plants, -) actions to reduce the stress on reactor staff, -) the shortening of downtimes, -) the comparison of production costs, and -) the in-line 3-dimensional monitoring of the nuclear core. (A.C.)

  5. Modeling synchronized calling behavior of Japanese tree frogs.

    Science.gov (United States)

    Aihara, Ikkyu

    2009-07-01

    We experimentally observed synchronized calling behavior of male Japanese tree frogs Hyla japonica; namely, while isolated single frogs called nearly periodically, a pair of interacting frogs called synchronously almost in antiphase or inphase. In this study, we propose two types of phase-oscillator models on different degrees of approximations, which can quantitatively explain the phase and frequency properties in the experiment. Moreover, it should be noted that, although the second model is obtained by fitting to the experimental data of the two synchronized states, the model can also explain the transitory dynamics in the interactive calling behavior, namely, the shift from a transient inphase state to a stable antiphase state. We also discuss the biological relevance of the estimated parameter values to calling behavior of Japanese tree frogs and the possible biological meanings of the synchronized calling behavior.

  6. FROG: The Fast And Realistic OpenGL Event Displayer

    CERN Document Server

    Quertenmont, Loic

    2009-01-01

    FROG [1] [2] is a generic framework dedicated to visualisation of events in high energy experiment. It is suitable to any particular physics experiment or detector design. The code is light (< 3 MB) and fast (browsing time 20 events per second for a large High Energy Physics experiment) and can run on various operating systems, as its object-oriented structure (C++) relies on the cross-platform OPENGL [3] and GLUT [4] libraries. Moreover, FROG does not require installation of third party libraries for the visualisation. This documents describes the features and principles of FROG version 1.106, its working scheme and numerous functionalities such as: 3D and 2D visualisation, graphical user interface, mouse interface, configuration files, production of pictures of various format, integration of personal objects, etc. Finally the application of FROG for physic experiment/environement, such as Gastof, CMS, ILD, Delphes will be presented for illustration.

  7. Heavy point frog performance under passenger vehicles : final report.

    Science.gov (United States)

    2016-06-01

    Federal Railroad Administration contracted with the Transportation Technology Center, Inc., Pueblo, Colorado, to conduct an : investigation of passenger vehicle performance running through heavy point frog (HPF) up to speeds of 110 mph. A NUCARS : ...

  8. Frog tongue surface microstructures: functional and evolutionary patterns

    Science.gov (United States)

    Gorb, Stanislav N

    2016-01-01

    Summary Frogs (Lissamphibia: Anura) use adhesive tongues to capture fast moving, elusive prey. For this, the tongues are moved quickly and adhere instantaneously to various prey surfaces. Recently, the functional morphology of frog tongues was discussed in context of their adhesive performance. It was suggested that the interaction between the tongue surface and the mucus coating is important for generating strong pull-off forces. However, despite the general notions about its importance for a successful contact with the prey, little is known about the surface structure of frog tongues. Previous studies focused almost exclusively on species within the Ranidae and Bufonidae, neglecting the wide diversity of frogs. Here we examined the tongue surface in nine different frog species, comprising eight different taxa, i.e., the Alytidae, Bombinatoridae, Megophryidae, Hylidae, Ceratophryidae, Ranidae, Bufonidae, and Dendrobatidae. In all species examined herein, we found fungiform and filiform papillae on the tongue surface. Further, we observed a high degree of variation among tongues in different frogs. These differences can be seen in the size and shape of the papillae, in the fine-structures on the papillae, as well as in the three-dimensional organization of subsurface tissues. Notably, the fine-structures on the filiform papillae in frogs comprise hair-like protrusions (Megophryidae and Ranidae), microridges (Bufonidae and Dendrobatidae), or can be irregularly shaped or absent as observed in the remaining taxa examined herein. Some of this variation might be related to different degrees of adhesive performance and may point to differences in the spectra of prey items between frog taxa. PMID:27547606

  9. Evidence of auditory insensitivity to vocalization frequencies in two frogs

    DEFF Research Database (Denmark)

    Goutte, Sandra; Mason, Matthew J; Christensen-Dalsgaard, Jakob

    2017-01-01

    The emergence and maintenance of animal communication systems requires the co-evolution of signal and receiver. Frogs and toads rely heavily on acoustic communication for coordinating reproduction and typically have ears tuned to the dominant frequency of their vocalizations, allowing discriminat...... by their high toxicity might help to explain why calling has not yet disappeared, and that visual communication may have replaced auditory in these colourful, diurnal frogs....

  10. Prespermatogenesis and early spermatogenesis in frogs.

    Science.gov (United States)

    Haczkiewicz, Katarzyna; Rozenblut-Kościsty, Beata; Ogielska, Maria

    2017-06-01

    Spermatogenesis in frogs was for the first time divided into two phases: prespermatogenesis, when gonocytes proliferate in developing tadpole testes, and active spermatogenesis when spermatogonial stem cells (i.e. descendants of gonocytes), either self-renew or enter into meiotic cycles within cysts formed by Sertoli cells. We argue that amphibian larval gonocytes are homologues to mammalian gonocytes, whereas spermatogonial stem cells (SSCs) in adult frogs are homologous to mammalian single spermatogonia (A s ). Gonocytes constitute sex cords, i.e. the precursors of seminiferous tubules; they are bigger than SSCs and differ in morphology and ultrastructure. The nuclear envelope in gonocytes formed deep finger-like invaginations absent in SSCs. All stages of male germ cells contained lipid droplets, which were surrounded by glycogen in SSCs, but not in gonocytes. Mitochondria in gonocytes had enlarged edges of cristae, and in SSCs also lamellar mitochondria appeared. Minimal duration of prespermatogenesis was 46days after gonadal sex differentiation, but usually it lasted longer. SSCs give rise to secondary spermatogonia (equal to mammalian A, In, and B). Their lowest number inside a cyst was eight and this indicated the minimal number of cell cycles (three) of secondary spermatogonia necessary to enter meiosis. We sorted them according to the number of cell cycles (from 8 to 256 cells). This number is similar to that recorded for mammals as the result of a single A s proliferation. The number of secondary spermatogonia correlates with the volume of a cyst. The general conclusion is that spermatogenesis in amphibians and mammals follows basically the same scheme. Copyright © 2017 Elsevier GmbH. All rights reserved.

  11. The Frog in Ancient Egypt, with Unpublished Frog Statues, Amulets, and other Related Objects in the Agricultural and Mallawy Museums in Egypt

    Directory of Open Access Journals (Sweden)

    dr.Marzouk Al-sayed Aman

    2011-01-01

    Full Text Available Frogs belong to the class of 'amphibians'. They are cold-blooded animals, and they hibernate during winter. The life cycle of frogs begins with mating, laying eggs, developing into tadpoles in eggs, and then appearing as young frogs without tails. The frog was known in ancient Egypt as abnx, abxn, and qrr. The frog had a great role in ancient Egyptian mythology. It was connected with the mythology of creation. A number of gods and goddesses were connected with the frog such as Heqet, Ptah, Heh HHw ,Kek kkw , Nun nnw, and Amun Imn. Frog amulets were worn by the living to provide fertility, and were buried with the dead to protect and rejuvenate them. Frogs were often mummified with the dead as magical amulets to ensure rebirth. An image of a frog was depicted on apotropaic wands, as its role was the protector of the house hold and guardian of pregnant women .With the official prevalence of Christianity in Egypt in the fourth century AD., the frog was still used as a Coptic symbol of resurrection and rebirth. In this paper, the author will try to publish some of the unpublished frog statues, amulets, and other related objects in the agricultural and Mallawy museums in Egypt.

  12. Mitochondrial DNA mapping of social-biological interactions in Brazilian Amazonian African-descendant populations

    Directory of Open Access Journals (Sweden)

    Bruno Maia Carvalho

    2008-01-01

    Full Text Available The formation of the Brazilian Amazonian population has historically involved three main ethnic groups, Amerindian, African and European. This has resulted in genetic investigations having been carried out using classical polymorphisms and molecular markers. To better understand the genetic variability and the micro-evolutionary processes acting in human groups in the Brazilian Amazon region we used mitochondrial DNA to investigate 159 maternally unrelated individuals from five Amazonian African-descendant communities. The mitochondrial lineage distribution indicated a contribution of 50.2% from Africans (L0, L1, L2, and L3, 46.6% from Amerindians (haplogroups A, B, C and D and a small European contribution of 1.3%. These results indicated high genetic diversity in the Amerindian and African lineage groups, suggesting that the Brazilian Amazonian African-descendant populations reflect a possible population amalgamation of Amerindian women from different Amazonian indigenous tribes and African women from different geographic regions of Africa who had been brought to Brazil as slaves. The present study partially mapped the historical biological and social interactions that had occurred during the formation and expansion of Amazonian African-descendant communities.

  13. A Miocene hyperdiverse crocodylian community reveals peculiar trophic dynamics in proto-Amazonian mega-wetlands

    Science.gov (United States)

    Salas-Gismondi, Rodolfo; Flynn, John J.; Baby, Patrice; Tejada-Lara, Julia V.; Wesselingh, Frank P.; Antoine, Pierre-Olivier

    2015-01-01

    Amazonia contains one of the world's richest biotas, but origins of this diversity remain obscure. Onset of the Amazon River drainage at approximately 10.5 Ma represented a major shift in Neotropical ecosystems, and proto-Amazonian biotas just prior to this pivotal episode are integral to understanding origins of Amazonian biodiversity, yet vertebrate fossil evidence is extraordinarily rare. Two new species-rich bonebeds from late Middle Miocene proto-Amazonian deposits of northeastern Peru document the same hyperdiverse assemblage of seven co-occurring crocodylian species. Besides the large-bodied Purussaurus and Mourasuchus, all other crocodylians are new taxa, including a stem caiman—Gnatusuchus pebasensis—bearing a massive shovel-shaped mandible, procumbent anterior and globular posterior teeth, and a mammal-like diastema. This unusual species is an extreme exemplar of a radiation of small caimans with crushing dentitions recording peculiar feeding strategies correlated with a peak in proto-Amazonian molluscan diversity and abundance. These faunas evolved within dysoxic marshes and swamps of the long-lived Pebas Mega-Wetland System and declined with inception of the transcontinental Amazon drainage, favouring diversification of longirostrine crocodylians and more modern generalist-feeding caimans. The rise and demise of distinctive, highly productive aquatic ecosystems substantially influenced evolution of Amazonian biodiversity hotspots of crocodylians and other organisms throughout the Neogene. PMID:25716785

  14. Higher Education and Urban Migration for Community Resilience: Indigenous Amazonian Youth Promoting Place-Based Livelihoods and Identities in Peru

    Science.gov (United States)

    Steele, Diana

    2018-01-01

    This paper offers an ethnographic analysis of indigenous Peruvian Amazonian youth pursuing higher education through urban migration to contribute to the resilience of their communities, place-based livelihoods, and indigenous Amazonian identities. Youth and their communities promoted education and migration as powerful tools in the context of…

  15. Prostaglandin E2 release from dermis regulates sodium permeability of frog skin epithelium

    DEFF Research Database (Denmark)

    Rytved, Klaus A.; Brodin, Birger; Nielsen, Robert

    1995-01-01

    Arachidonic acid, cAMP, epithelium, frog skin, intracellular calcium, prostaglandin E*U2, sodium transport, tight epithelium.......Arachidonic acid, cAMP, epithelium, frog skin, intracellular calcium, prostaglandin E*U2, sodium transport, tight epithelium....

  16. Resurrecting an Extinct Species: Archival DNA, Taxonomy, and Conservation of the Vegas Valley Leopard Frog

    Science.gov (United States)

    Suggestions that the extinct Vegas Valley leopard frog (Rana fisheri = Lithobates fisheri) may have been synonymous with one of several declining species has complicated recovery planning for imperiled leopard frogs in southwestern North America. To address this concern, we recon...

  17. Female preferences for aposematic signal components in a polymorphic poison frog

    NARCIS (Netherlands)

    Maan, Martine E.; Cummings, Molly E.

    Aposematic signals may be subject to conflicting selective pressures from predators and conspecifics. We studied female preferences for different components of aposematic coloration in the polymorphic poison frog Oophaga pumilio across several phenotypically distinct populations. This frog shows

  18. Panamanian frog species host unique skin bacterial communities

    Directory of Open Access Journals (Sweden)

    Lisa K. Belden

    2015-10-01

    Full Text Available Vertebrates, including amphibians, host diverse symbiotic microbes that contribute to host disease resistance. Globally, and especially in montane tropical systems, many amphibian species are threatened by a chytrid fungus, Batrachochytrium dendrobatidis (Bd, that causes a lethal skin disease. Bd therefore may be a strong selective agent on the diversity and function of the microbial communities inhabiting amphibian skin. In Panamá, amphibian population declines and the spread of Bd have been tracked. In 2012, we completed a field survey in Panamá to examine frog skin microbiota in the context of Bd infection. We focused on three frog species and collected two skin swabs per frog from a total of 136 frogs across four sites that varied from west to east in the time since Bd arrival. One swab was used to assess bacterial community structure using 16S rRNA amplicon sequencing and to determine Bd infection status, and one was used to assess metabolite diversity, as the bacterial production of anti-fungal metabolites is an important disease resistance function. The skin microbiota of the three Panamanian frog species differed in OTU (operational taxonomic unit, ~bacterial species community composition and metabolite profiles, although the pattern was less strong for the metabolites. Comparisons between frog skin bacterial communities from Panamá and the US suggest broad similarities at the phylum level, but key differences at lower taxonomic levels. In our field survey in Panamá, across all four sites, only 35 individuals (~26% were Bd infected. There was no clustering of OTUs or metabolite profiles based on Bd infection status and no clear pattern of west-east changes in OTUs or metabolite profiles across the four sites. Overall, our field survey data suggest that different bacterial communities might be producing broadly similar sets of metabolites across frog hosts and sites. Community structure and function may not be as tightly coupled in

  19. Phylogeny and biogeography of South Chinese brown frogs (Ranidae, Anura).

    Science.gov (United States)

    Zhou, Yu; Wang, Sirui; Zhu, Hedan; Li, Pipeng; Yang, Baotian; Ma, Jianzhang

    2017-01-01

    Few studies have explored the role of Cenozoic tectonic evolution in shaping the patterns and processes of extant animal distributions in and around East Asia. In this study, we selected South Chinese brown frogs as a model to examine the phylogenetic and biogeographical consequences of Miocene tectonic events within South China and its margins. We used mitochondrial and nuclear molecular data to reconstruct phylogenetic interrelationships among Chinese brown frogs using Bayesian and maximum likelihood analyses. The phylogeny results show that there are four main clades of Chinese brown frogs. Excepting the three commonly known Chinese brown frog species groups, R. maoershanensis forms an independent clade nearest to the R. japonica group. Phylogeny and P-distance analyses confirmed R. maoershanensis as a valid species. Among South Chinese brown frogs, there are four subclades associated with four geographical areas: (I) R. maoershanensis; (II) R. japonica; (III) R. chaochiaoensis; and (IV) other species of the R. longicrus species group. Divergence times, estimated using mitochondrial sequences, place the vicariance events among the four subclades in the middle to late Miocene epoch. Our results suggest that (1) South Chinese brown frogs originated due to a vicariance event separating them from the R. chensinensis species group at the time of the Geological movement (~18 million years ago, Ma) in southern Tibet and the Himalayan region; (2) the separation and speciation of R. maoershanensis from the R. japonica group occurred due to the dry climate at approximately 16 Ma; (3) South Chinese brown frogs migrated from South China to Japan at the time (~10.8 Ma) that the global sea-level fell and the East China Sea Shelf Basin was swamp facies, when a land gallery may have formed across the sea to connect the two areas; and (4) R. chaochiaoensis separated from other species of the R. longicrus species group during the uplift of the Tibetan Plateau at approximately 9

  20. Cystic urolithiasis in captive waxy monkey frogs (Phyllomedusa sauvagii).

    Science.gov (United States)

    Archibald, Kate E; Minter, Larry J; Dombrowski, Daniel S; O'Brien, Jodi L; Lewbart, Gregory A

    2015-03-01

    The waxy monkey frog (Phyllomedusa sauvagii) is an arboreal amphibian native to arid regions of South America, and it has developed behavioral and physiologic adaptations to permit survival in dry environments. These adaptations include a uricotelic nitrogen metabolism and unique cutaneous lipid excretions to prevent evaporative water loss. Uroliths are a rare finding in amphibians. Six adult, presumed wild-caught waxy monkey frogs housed in a museum animal collection were diagnosed with cystic urolithiasis over a 7-yr period, and a single animal was diagnosed with four recurrent cases. Six cases were identified incidentally at routine physical or postmortem examination and four cases were identified during veterinary evaluation for coelomic distension, lethargy, anorexia, and increased soaking behavior. Calculi were surgically removed from three frogs via cystotomy, and a single frog underwent three cystotomies and two cloacotomies for recurrent urolithiasis. Two frogs died within the 24-hr postoperative period. Two representative calculi from a single frog were submitted for component analysis and found to consist of 100% ammonium urate. In the present report, cystic calculi are proposed to be the result of a high-protein diet based on a single invertebrate source, coupled with uricotelism, dehydration, increased cutaneous water loss, body temperature fluctuations facilitating supersaturation of urine, and subsequent accumulation and precipitation of urogenous wastes within the urinary bladder. Surgical cystotomy represents a short-term treatment strategy for this condition. Preventative measures, such as supplying a diversified and balanced diet in addition to environmental manipulation aimed at promoting adequate hydration, are anticipated to be more-rewarding management tools for cystic urolithiasis in the waxy monkey frog.

  1. Carbon Dioxide and Methane Evasion from Amazonian Rivers and Lakes

    Science.gov (United States)

    Melack, J. M.; Barbosa, P.; Schofield, V.; Amaral, J.; Forsberg, B.; Farjalla, V.

    2013-12-01

    Floodplains, with their mosaic of aquatic habitats, constitute the majority of the wetlands of South America. We report 1) estimates of CH4 and CO2 flux from Amazonian floodplain lakes and rivers during low, rising and high water periods, and 2) identify environmental factors regulating these fluxes. We sampled 10 floodplain lakes, 4 tributaries of Solimões River, 6 stations on the Solimões main stem and 1 station on the Madeira, Negro and Amazonas rivers. Diffusive fluxes were measured with static floating chambers. CH4 fluxes were highly variable, with the majority of the values lower than 5 mmol m-2 d-1. For the lakes, no significant differences among the periods were found. CH4 concentration in the water and water temperature were the two main environmental factors regulating the diffusive flux. Our results highlight the importance of considering both the spatial and temporal scales when estimating CH4 fluxes for a region. CO2 fluxes from water to atmosphere ranged between 327 and -21 mmol m-2 d-1, averaging 58 mmol m-2 d-1. We found higher evasion rates in lakes than in rivers. For both systems the lowest rates were found in low water. pH and dissolved oxygen, phosphorous and organic carbon were the main factors correlated to CO2 evasion from the water bodies.

  2. The impact of Amazonian deforestation on Amazon basin rainfall

    Science.gov (United States)

    Spracklen, D. V.; Garcia-Carreras, L.

    2015-11-01

    We completed a meta-analysis of regional and global climate model simulations (n = 96) of the impact of Amazonian deforestation on Amazon basin rainfall. Across all simulations, mean (±1σ) change in annual mean Amazon basin rainfall was -12 ± 11%. Variability in simulated rainfall was not explained by differences in model resolution or surface parameters. Across all simulations we find a negative linear relationship between rainfall and deforestation extent, although individual studies often simulate a nonlinear response. Using the linear relationship, we estimate that deforestation in 2010 has reduced annual mean rainfall across the Amazon basin by 1.8 ± 0.3%, less than the interannual variability in observed rainfall. This may explain why a reduction in Amazon rainfall has not consistently been observed. We estimate that business-as-usual deforestation (based on deforestation rates prior to 2004) would lead to an 8.1 ± 1.4% reduction in annual mean Amazon basin rainfall by 2050, greater than natural variability.

  3. Rapid tree carbon stock recovery in managed Amazonian forests.

    Science.gov (United States)

    Rutishauser, Ervan; Hérault, Bruno; Baraloto, Christopher; Blanc, Lilian; Descroix, Laurent; Sotta, Eleneide Doff; Ferreira, Joice; Kanashiro, Milton; Mazzei, Lucas; d'Oliveira, Marcus V N; de Oliveira, Luis C; Peña-Claros, Marielos; Putz, Francis E; Ruschel, Ademir R; Rodney, Ken; Roopsind, Anand; Shenkin, Alexander; da Silva, Katia E; de Souza, Cintia R; Toledo, Marisol; Vidal, Edson; West, Thales A P; Wortel, Verginia; Sist, Plinio

    2015-09-21

    While around 20% of the Amazonian forest has been cleared for pastures and agriculture, one fourth of the remaining forest is dedicated to wood production. Most of these production forests have been or will be selectively harvested for commercial timber, but recent studies show that even soon after logging, harvested stands retain much of their tree-biomass carbon and biodiversity. Comparing species richness of various animal taxa among logged and unlogged forests across the tropics, Burivalova et al. found that despite some variability among taxa, biodiversity loss was generally explained by logging intensity (the number of trees extracted). Here, we use a network of 79 permanent sample plots (376 ha total) located at 10 sites across the Amazon Basin to assess the main drivers of time-to-recovery of post-logging tree carbon (Table S1). Recovery time is of direct relevance to policies governing management practices (i.e., allowable volumes cut and cutting cycle lengths), and indirectly to forest-based climate change mitigation interventions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Pesticide use and biodiversity conservation in the Amazonian agricultural frontier.

    Science.gov (United States)

    Schiesari, Luis; Waichman, Andrea; Brock, Theo; Adams, Cristina; Grillitsch, Britta

    2013-06-05

    Agricultural frontiers are dynamic environments characterized by the conversion of native habitats to agriculture. Because they are currently concentrated in diverse tropical habitats, agricultural frontiers are areas where the largest number of species is exposed to hazardous land management practices, including pesticide use. Focusing on the Amazonian frontier, we show that producers have varying access to resources, knowledge, control and reward mechanisms to improve land management practices. With poor education and no technical support, pesticide use by smallholders sharply deviated from agronomical recommendations, tending to overutilization of hazardous compounds. By contrast, with higher levels of technical expertise and resources, and aiming at more restrictive markets, large-scale producers adhered more closely to technical recommendations and even voluntarily replaced more hazardous compounds. However, the ecological footprint increased significantly over time because of increased dosage or because formulations that are less toxic to humans may be more toxic to other biodiversity. Frontier regions appear to be unique in terms of the conflicts between production and conservation, and the necessary pesticide risk management and risk reduction can only be achieved through responsibility-sharing by diverse stakeholders, including governmental and intergovernmental organizations, NGOs, financial institutions, pesticide and agricultural industries, producers, academia and consumers.

  5. Mosquitoes of eastern Amazonian Ecuador: biodiversity, bionomics and barcodes

    Directory of Open Access Journals (Sweden)

    Yvonne-Marie Linton

    2013-01-01

    Full Text Available Two snapshot surveys to establish the diversity and ecological preferences of mosquitoes (Diptera: Culicidae in the terra firme primary rain forest surrounding the Tiputini Biodiversity Station in the UNESCO Yasuní Biosphere Reserve of eastern Amazonian Ecuador were carried out in November 1998 and May 1999. The mosquito fauna of this region is poorly known; the focus of this study was to obtain high quality link-reared specimens that could be used to unequivocally confirm species level diversity through integrated systematic study of all life stages and DNA sequences. A total of 2,284 specimens were preserved; 1,671 specimens were link-reared with associated immature exuviae, all but 108 of which are slide mounted. This study identified 68 unique taxa belonging to 17 genera and 27 subgenera. Of these, 12 are new to science and 37 comprise new country records. DNA barcodes [658-bp of the mtDNA cytochrome c oxidase ( COI I gene] are presented for 58 individuals representing 20 species and nine genera. DNA barcoding proved useful in uncovering and confirming new species and we advocate an integrated systematics approach to biodiversity studies in future. Associated bionomics of all species collected are discussed. An updated systematic checklist of the mosquitoes of Ecuador (n = 179 is presented for the first time in 60 years.

  6. Mosquitoes of eastern Amazonian Ecuador: biodiversity, bionomics and barcodes.

    Science.gov (United States)

    Linton, Yvonne-Marie; Pecor, James E; Porter, Charles H; Mitchell, Luke Brett; Garzón-Moreno, Andrés; Foley, Desmond H; Pecor, David Brooks; Wilkerson, Richard C

    2013-01-01

    Two snapshot surveys to establish the diversity and ecological preferences of mosquitoes (Diptera: Culicidae) in the terra firme primary rain forest surrounding the Tiputini Biodiversity Station in the UNESCO Yasuní Biosphere Reserve of eastern Amazonian Ecuador were carried out in November 1998 and May 1999. The mosquito fauna of this region is poorly known; the focus of this study was to obtain high quality link-reared specimens that could be used to unequivocally confirm species level diversity through integrated systematic study of all life stages and DNA sequences. A total of 2,284 specimens were preserved; 1,671 specimens were link-reared with associated immature exuviae, all but 108 of which are slide mounted. This study identified 68 unique taxa belonging to 17 genera and 27 subgenera. Of these, 12 are new to science and 37 comprise new country records. DNA barcodes [658-bp of the mtDNA cytochrome c oxidase (COI) I gene] are presented for 58 individuals representing 20 species and nine genera. DNA barcoding proved useful in uncovering and confirming new species and we advocate an integrated systematics approach to biodiversity studies in future. Associated bionomics of all species collected are discussed. An updated systematic checklist of the mosquitoes of Ecuador (n=179) is presented for the first time in 60 years.

  7. Poor prospects for avian biodiversity in Amazonian oil palm.

    Science.gov (United States)

    Lees, Alexander C; Moura, Nárgila G; de Almeida, Arlete Silva; Vieira, Ima C G

    2015-01-01

    Expansion of oil palm plantations across the humid tropics has precipitated massive loss of tropical forest habitats and their associated speciose biotas. Oil palm plantation monocultures have been identified as an emerging threat to Amazonian biodiversity, but there are no quantitative studies exploring the impact of these plantations on the biome's biota. Understanding these impacts is extremely important given the rapid projected expansion of oil palm cultivation in the basin. Here we investigate the biodiversity value of oil palm plantations in comparison with other dominant regional land-uses in Eastern Amazonia. We carried out bird surveys in oil palm plantations of varying ages, primary and secondary forests, and cattle pastures. We found that oil palm plantations retained impoverished avian communities with a similar species composition to pastures and agrarian land-uses and did not offer habitat for most forest-associated species, including restricted range species and species of conservation concern. On the other hand, the forests that the oil palm companies are legally obliged to protect hosted a relatively species-rich community including several globally-threatened bird species. We consider oil palm to be no less detrimental to regional biodiversity than other agricultural land-uses and that political pressure exerted by large landowners to allow oil palm to count as a substitute for native forest vegetation in private landholdings with forest restoration deficits would have dire consequences for regional biodiversity.

  8. Poor prospects for avian biodiversity in Amazonian oil palm.

    Directory of Open Access Journals (Sweden)

    Alexander C Lees

    Full Text Available Expansion of oil palm plantations across the humid tropics has precipitated massive loss of tropical forest habitats and their associated speciose biotas. Oil palm plantation monocultures have been identified as an emerging threat to Amazonian biodiversity, but there are no quantitative studies exploring the impact of these plantations on the biome's biota. Understanding these impacts is extremely important given the rapid projected expansion of oil palm cultivation in the basin. Here we investigate the biodiversity value of oil palm plantations in comparison with other dominant regional land-uses in Eastern Amazonia. We carried out bird surveys in oil palm plantations of varying ages, primary and secondary forests, and cattle pastures. We found that oil palm plantations retained impoverished avian communities with a similar species composition to pastures and agrarian land-uses and did not offer habitat for most forest-associated species, including restricted range species and species of conservation concern. On the other hand, the forests that the oil palm companies are legally obliged to protect hosted a relatively species-rich community including several globally-threatened bird species. We consider oil palm to be no less detrimental to regional biodiversity than other agricultural land-uses and that political pressure exerted by large landowners to allow oil palm to count as a substitute for native forest vegetation in private landholdings with forest restoration deficits would have dire consequences for regional biodiversity.

  9. An endogenous bile acid and dietary sucrose from skin secretions of alkaloid-sequestering poison frogs.

    Science.gov (United States)

    Clark, Valerie C; Harinantenaina, Liva; Zeller, Martin; Ronto, William; Rocca, James; Dossey, Aaron T; Rakotondravony, Daniel; Kingston, David G I; Shaw, Chris

    2012-03-23

    The skins of Madagascar poison frogs (Mantella) and certain Neotropical poison frogs (Epipedobates, Dendrobates) secrete the new bile acid tauromantellic acid (1), which was found in both wild-caught and captive-born frogs. This is the first molecule of endogenous origin detected in skin secretions from these taxa. Sucrose was also detected in secretions from wild-caught Mantella but not in captive-born frogs, suggesting a dietary origin.

  10. [FRancilian Oncogeriatric Group (FROG)'s focus on management of elderly patients with bladder cancer].

    Science.gov (United States)

    Ghebriou, Djamel; Avenin, Danièle; Caillet, Philippe; Mongiat-Artus, Pierre; Durdux, Catherine; Massard, Christophe; Culine, Stéphane

    2014-09-01

    Bladder cancer is diagnosed more often in the elderly. The most effective treatment strategies are mostly very aggressive and are not applicable to all patients in a very heterogeneous population. However, effective options exist to treat the most vulnerable subjects. A multidisciplinary approach including a geriatric assessment is essential for optimal adaptation of treatment. The FRancilian Oncogeriatric Group (FROG) conducted a comprehensive literature search in order to review the applicable therapeutic options according to oncological and geriatric settings. International recommendations are essential to harmonize the management of elderly patients with bladder cancer.

  11. Acute and chronic effects of acidic pH on four subtropical frog species

    African Journals Online (AJOL)

    We conducted acute (LC50) and chronic acid tolerance bioassays on embryos and tadpoles of four frog species found in the park, i.e., Chiromantis xerampelina (Southern Foam Nest Frog), Pyxicephalus edulis (African Bullfrog), Amietophrynus maculatus (Flat-backed Toad) and Hildebrandtia ornata (Ornate Frog), using ...

  12. Radioimmunoassay of plasma corticotropin in the edible Frog Rana esculenta L

    International Nuclear Information System (INIS)

    Vaudry, Hubert; Leboulenger, Francois; Dupont, Willy; Vaillant, Rene

    1975-01-01

    In the green Frog (Rana esculenta) the plasma contains a polypeptide immunologically related to human and porcine corticotropins. A radioimmunoassay capable of detecting 4.10 -12 g hog ACTH has been used for a direct plasma ACTH assay in the Frog. Using this method the ACTH rate was determined both in untreated frogs and in animals under various experimental conditions [fr

  13. Effects of the Chytrid fungus on the Tarahumara frog (Rana tarahumarae) in Arizona and Sonora, Mexico

    Science.gov (United States)

    Stephen F. Hale; Philip C. Rosen; James L. Jarchow; Gregory A. Bradley

    2005-01-01

    We conducted histological analyses on museum specimens collected 1975-1999 from 10 sites in Arizona and Sonora to test for the pathogenic chytrid fungus (Batrachochytrium dendrobatidis) in ranid frogs, focusing on the Tarahumara frog (Rana tarahumarae). During 1981-2000, frogs displaying disease signs were found in the field, and...

  14. 49 CFR 236.327 - Switch, movable-point frog or split-point derail.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Switch, movable-point frog or split-point derail..., AND APPLIANCES Interlocking Rules and Instructions § 236.327 Switch, movable-point frog or split-point derail. Switch, movable-point frog, or split-point derail equipped with lock rod shall be maintained so...

  15. Ocurrence of Cryptosporidium spp. in Amazonian manatees (Trichechus inunguis, Natterer, 1883

    Directory of Open Access Journals (Sweden)

    Maria Aparecida da Glória Faustino

    2007-09-01

    Full Text Available The apicomplexa protozoa Cryptosporidium infects several mammals, including terrestrial and aquatic species. In the epidemiology of this infection, the ingestion of water and/or food contamined with oocysts comprises the main mechanism of transmission to susceptible animals. Among the Sirenians, the occurrence of this coccidium has been reported in dugongs (Dugong dugon and Antillean manatee (Trichechus manatus manatus. The present study was conducted with the aim of verifying the occurrence of Cryptosporidium spp. in Amazonian manatee. For this purpose, fecal samples were collected from ten free-ranging Amazonian manatees, two specimens in captivity, and 103 supernatants fecal samples. The samples were processed by the sedimentation method in formol-ether and Kinyoun stain technique for the presence of Cryptosporidium spp.. The positive samples were then submitted to Direct Immunoflorescence Test. The results showed 4.34% (05/115 of positive samples. This is the first report of Cryptosporidium spp. in the Amazonian manatee.

  16. Use of amazonian anthropogenic soils: Comparison between Caboclos communities and Tikunas indigenous group

    International Nuclear Information System (INIS)

    Torres Sanabria, Camilo; Cuartas Ricaurte, Jorge Armando

    2013-01-01

    In general terms, Amazonian soils are infertile and have several constraints for agricultural production. However, use by ancient human societies since pre-columbian times has driven landscape transformation of massive areas and development of anthropogenic soils called Terra Preta do Indio (TP) or Amazonian Dark Earths (ADE). ADE characterization, in terms of fertility and composition, has allowed the development of intensive agricultural activities over time. The current use of ADE for the Brazilian amazon peasants (Caboclos) is different from the indigenous communities in Colombia. The indigenous people in Colombia (Tikunas) no use this type of soils on behalf of cultural restrictions that avoid the use of ancient places. We are comparing the institutional conditions, migrations, social characterization and cultural factors that determine the use/no-use of these soils by the Amazonian societies.

  17. Tourism and the Conservation of Critically Endangered Frogs

    Science.gov (United States)

    Morrison, Clare; Simpkins, Clay; Castley, J. Guy; Buckley, Ralf C.

    2012-01-01

    Protected areas are critical for the conservation of many threatened species. Despite this, many protected areas are acutely underfunded, which reduces their effectiveness significantly. Tourism is one mechanism to promote and fund conservation in protected areas, but there are few studies analyzing its tangible conservation outcomes for threatened species. This study uses the 415 IUCN critically endangered frog species to evaluate the contribution of protected area tourism revenue to conservation. Contributions were calculated for each species as the proportion of geographic range inside protected areas multiplied by the proportion of protected area revenues derived from tourism. Geographic ranges were determined from IUCN Extent of Occurrence maps. Almost 60% (239) of critically endangered frog species occur in protected areas. Higher proportions of total range are protected in Nearctic, Australasian and Afrotopical regions. Tourism contributions to protected area budgets ranged from 5–100%. These financial contributions are highest for developing countries in the Afrotropical, Indomalayan and Neotropical regions. Data for both geographic range and budget are available for 201 critically endangered frog species with proportional contributions from tourism to species protection ranging from 0.8–99%. Tourism's financial contributions to critically endangered frog species protection are highest in the Afrotropical region. This study uses a coarse measure but at the global scale it demonstrates that tourism has significant potential to contribute to global frog conservation efforts. PMID:22984440

  18. Marsh frogs, Pelophylax ridibundus, determine migratory direction by magnetic field.

    Science.gov (United States)

    Shakhparonov, Vladimir V; Ogurtsov, Sergei V

    2017-01-01

    Orientation by magnetic cues appears to be adaptive during animal migrations. Whereas the magnetic orientation in birds, mammals, and urodele amphibians is being investigated intensively, the data about anurans are still scarce. This study tests whether marsh frogs could determine migratory direction between the breeding pond and the wintering site by magnetic cues in the laboratory. Adult frogs (N = 32) were individually tested in the T-maze 127 cm long inside the three-axis Helmholtz coil system (diameter 3 m). The arms of the maze were positioned parallel to the natural migratory route of this population when measured in accordance with magnetic field. The frogs were tested under two-motivational conditions mediated by temperature/light regime: the breeding migratory state and the wintering state. The frogs' choice in a T-maze was evident only when analyzed in accordance with the direction of the magnetic field: they moved along the migratory route to the breeding pond and followed the reversion of the horizontal component of the magnetic field. This preference has been detected in both sexes only in the breeding migratory state. This suggests that adult ranid frogs can obtain directional information from the Earth's magnetic field as was shown earlier in urodeles and anuran larvae.

  19. Sophisticated Communication in the Brazilian Torrent Frog Hylodes japi

    Science.gov (United States)

    de Sá, Fábio P.; Zina, Juliana; Haddad, Célio F. B.

    2016-01-01

    Intraspecific communication in frogs plays an important role in the recognition of conspecifics in general and of potential rivals or mates in particular and therefore with relevant consequences for pre-zygotic reproductive isolation. We investigate intraspecific communication in Hylodes japi, an endemic Brazilian torrent frog with territorial males and an elaborate courtship behavior. We describe its repertoire of acoustic signals as well as one of the most complex repertoires of visual displays known in anurans, including five new visual displays. Previously unknown in frogs, we also describe a bimodal inter-sexual communication system where the female stimulates the male to emit a courtship call. As another novelty for frogs, we show that in addition to choosing which limb to signal with, males choose which of their two vocal sacs will be used for visual signaling. We explain how and why this is accomplished. Control of inflation also provides additional evidence that vocal sac movement and color must be important for visual communication, even while producing sound. Through the current knowledge on visual signaling in Neotropical torrent frogs (i.e. hylodids), we discuss and highlight the behavioral diversity in the family Hylodidae. Our findings indicate that communication in species of Hylodes is undoubtedly more sophisticated than we expected and that visual communication in anurans is more widespread than previously thought. This is especially true in tropical regions, most likely due to the higher number of species and phylogenetic groups and/or to ecological factors, such as higher microhabitat diversity. PMID:26760304

  20. Frog sound identification using extended k-nearest neighbor classifier

    Science.gov (United States)

    Mukahar, Nordiana; Affendi Rosdi, Bakhtiar; Athiar Ramli, Dzati; Jaafar, Haryati

    2017-09-01

    Frog sound identification based on the vocalization becomes important for biological research and environmental monitoring. As a result, different types of feature extractions and classifiers have been employed to evaluate the accuracy of frog sound identification. This paper presents a frog sound identification with Extended k-Nearest Neighbor (EKNN) classifier. The EKNN classifier integrates the nearest neighbors and mutual sharing of neighborhood concepts, with the aims of improving the classification performance. It makes a prediction based on who are the nearest neighbors of the testing sample and who consider the testing sample as their nearest neighbors. In order to evaluate the classification performance in frog sound identification, the EKNN classifier is compared with competing classifier, k -Nearest Neighbor (KNN), Fuzzy k -Nearest Neighbor (FKNN) k - General Nearest Neighbor (KGNN)and Mutual k -Nearest Neighbor (MKNN) on the recorded sounds of 15 frog species obtained in Malaysia forest. The recorded sounds have been segmented using Short Time Energy and Short Time Average Zero Crossing Rate (STE+STAZCR), sinusoidal modeling (SM), manual and the combination of Energy (E) and Zero Crossing Rate (ZCR) (E+ZCR) while the features are extracted by Mel Frequency Cepstrum Coefficient (MFCC). The experimental results have shown that the EKNCN classifier exhibits the best performance in terms of accuracy compared to the competing classifiers, KNN, FKNN, GKNN and MKNN for all cases.

  1. Prevalence of Batrachochytrium dendrobatidis in three species of wild frogs on Prince Edward Island, Canada.

    Science.gov (United States)

    Forzán, M J; Vanderstichel, R; Hogan, N S; Teather, K; Wood, J

    2010-09-02

    Chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), has resulted in the decline or extinction of approximately 200 frog species worldwide. It has been reported throughout much of North America, but its presence on Prince Edward Island (PEI), on the eastern coast of Canada, was unknown. To determine the presence and prevalence of Bd on PEI, skin swabs were collected from 115 frogs from 18 separate sites across the province during the summer of 2009. The swabs were tested through single round end-point PCR for the presence of Bd DNA. Thirty-one frogs were positive, including 25/93 (27%) green frogs Lithobates (Rana) clamitans, 5/20 (25%) northern leopard frogs L. (R.) pipiens, and 1/2 (50%) wood frogs L. sylvaticus (formerly R. sylvatica); 12 of the 18 (67%) sites had at least 1 positive frog. The overall prevalence of Bd infection was estimated at 26.9% (7.2-46.7%, 95% CI). Prevalence amongst green frogs and leopard frogs was similar, but green frogs had a stronger PCR signal when compared to leopard frogs, regardless of age (p frogs, juveniles were more frequently positive than adults (p = 0.001). Green frogs may be the most reliable species to sample when looking for Bd in eastern North America. The 1 wood frog positive for Bd was found dead from chytridiomycosis; none of the other frogs that were positive for Bd by PCR showed any obvious signs of illness. Further monitoring will be required to determine what effect Bd infection has on amphibian population health on PEI.

  2. Feeding kinematics of phyllomedusine tree frogs.

    Science.gov (United States)

    Gray, L A; Nishikawa, K C

    1995-02-01

    Previous studies have demonstrated that the phyllomedusine hylids possess highly protrusible tongues, a derived characteristic within the family Hylidae. In the present study, the kinematics of the feeding behavior of a phyllomedusine species, Pachymedusa dacnicolor, was analyzed using high-speed video (180 frames s-1). Its behavior was compared with that of Hyla cinerea, a species with a weakly protrusible tongue. P. dacnicolor exhibits a faster rate of tongue protraction, a longer gape cycle and more variable feeding kinematics than H. cinerea. In addition, the tongue is used in a unique 'fly-swatter' fashion, to pin the prey to the substratum as the frog completes the lunge. The rapid tongue protraction, extended gape cycle and fly-swatter action may have evolved in response to a diet of large, rapidly moving insects. In addition, several duration variables of the feeding cycle were greater for misses than for captures and drops, which suggests that sensory feedback rather than biomechanics controls gape cycle duration.

  3. Prevalence and intensity of Alaria alata (Goeze, 1792) in water frogs and brown frogs in natural conditions.

    Science.gov (United States)

    Patrelle, Cécile; Portier, Julien; Jouet, Damien; Delorme, Daniel; Ferté, Hubert

    2015-12-01

    In the last 15 years, the mesocercariae of Alaria alata have frequently been reported in the wild boar during routine Trichinella inspections made compulsory for the trade of venison meat in Europe. If these studies have focused primarily on mesocercariae isolated from meat, few works have been done so far to understand the circulation of the parasite in natural conditions especially in the intermediate hosts. This study focuses on the second intermediate hosts of this parasite assessing the suitability of two amphibian groups-brown frogs and water frogs sensu lato-for mesocercarial infection on an area where A. alata has already been identified in water snails and wild boars. During this study, both groups showed to be suitable for mesocercarial infection, with high prevalence and parasite burdens. Prevalence was higher in the brown frog group (56.9 versus 11.54 % for water frogs) which would indicate that it is a preferential group for infection on the study area, though reasons for this remain to be investigated. No significant difference among prevalences was observed between tadpoles and frogs. This study, the first focusing on A. alata in these amphibians in Europe, provides further information on circulation of this parasite in natura.

  4. Paleoclimatic Comparisons Between Three Late Quaternary Amazonian Lacustrine Records

    Science.gov (United States)

    Cordeiro, R. C.; Martins, G. S.; Fontes, D.; Turcq, B.; Sifeddine, A.; Seoane, J. S.; Conceição, M. G.; Barbosa, M.; Rodrigues, R. A.; Moreira, L.

    2012-12-01

    In recent years many records made in the cores of ice has shown significant changes in temperature associated with changes in atmospheric composition. The most notable changes occur between the glacials and interglacials cycles. Climatic changes in tropical areas during the global climatic changes is highly debatable. Even today, there are many controversies about the extent of the occurrence of dry weather in the Amazon during glacial periods. In the region of São Gabriel da Cachoeira, polynic diagram of Lagoa da Pata showed that vegetation remained with elements of forest trees, with replacement of elements of cold weather during the last glacial. In Carajás were observed substitution forest to savannah, during the last glacial. We present here a comparison of organic and inorganic geochemical sediment record of tree distinct Amazonian sectors: Morro dos Seis Lagos (AM) is located at 0°17‧9.68″ N and 66°40‧36.18″ W (Lagoa da Pata, LPT V core position) located in the forested upper Rio Negro basin in humid climate area (~3000 mm/yr), Carajás Region at 5°50‧ to 6°35‧ S and 49°30‧ to 52°00‧ situated 800 m high in lateritic crust in south eastern Amazonia (1800mm/yr) and São Benedito Region (PA) at 9°7'0.87"S and 56°16'0.00"W (Lago do Saci, Sac01/05 core position) in south Amazonia with a mean precipitation as Carajás around 1800 mm/yr. A comparison of these records reveals important changes in the environmental history of the Amazonian hydrological regime during the late Quaternary. The results of geochemical analyses reveal three hydrological and climatic regimes from 50,000 cal yr BP until the present. The first phase, between 50,000 until ~25,000 cal yr BP, was characterized by relatively high lake level as suggested by high organic carbon values in Lagoa da Pata and Carajás principally in the beginning of the period. In Saci Lake in the beginning of the record (35,500 cal yr BP) high values of TOC were observed relatively to last

  5. Amazonian Buriti oil: chemical characterization and antioxidant potential

    Directory of Open Access Journals (Sweden)

    Speranza, P.

    2016-06-01

    Full Text Available Buriti oil is an example of an Amazonian palm oil of economic importance. The local population uses this oil for the prevention and treatment of different diseases; however, there are few studies in the literature that evaluate its properties. In this study, detailed chemical and antioxidant properties of Buriti oil were determined. The predominant fatty acid was oleic acid (65.6% and the main triacylglycerol classes were tri-unsaturated (50.0% and di-unsaturated-mono-saturated (39.3% triacylglycerols. The positional distribution of the classes of fatty acids on the triacylglycerol backbone indicated a saturated and unsaturated fatty acid relationship similar in the three-triacylglycerol positions. All tocopherol isomers were present, with a total content of 2364.1 mg·kg−1. α-tocopherol constitutes 48% of the total tocopherol content, followed by γ- tocopherol (45%. Total phenolic (107.0 mg gallic acid equivalent·g−1 oil and β-carotene (781.6 mg·kg−1 were particularly high in this oil. The highest antioxidant activity against the free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH was obtained at an oil concentration of 50 mg·mL−1 (73.15%. The antioxidant activity evaluated by the Oxygen Radical Absorbance Capacity (ORAC was 95.3 μmol Trolox equivalent·g−1 oil. These results serve to present Buriti oil as an Amazonian resource for cosmetic, food and pharmaceuticals purposes.El aceite de Buriti es un ejemplo de aceite de palma amazónica de gran importancia económica. La población local utiliza este aceite para la prevención y el tratamiento de diferentes enfermedades; sin embargo, hay pocos estudios científicos que evalúen sus propiedades. En este estudio, se determinaron las propiedades antioxidantes del aceite de Buriti. El ácido graso predominante fue el oleico (65,6 % y las principales clases de triglicéridos fueron tri-insaturadas (50,0 % y Di-insaturados-mono-saturada (39,3 %. La distribución posicional de las

  6. Radiation processing for the control of Salmonella in frog legs

    International Nuclear Information System (INIS)

    Nerkar, D.P.; Kumta, U.S.; Sreenivasan, A.

    1976-01-01

    Large consignments of frogs legs are exported annually from India. Failure to satisfy some of the strict microbiological standards, especially in relating to Salmonellae contamination, has resulted in the rejection of large quantities of the product in recent years. This has emphasised the need for better and more effective methods than those currently in use for the elimination of Salmonellae. With a view to developing an irradiation process for the control of this public health problem, commercial samples of frog legs have been screened to assess the incidence of Salmonella. The various serotypes have been identified and their radiation sensitivities determined. Based on these data, a radiation treatment of frozen frog legs for the elimination of Salmonella has been developed. (author)

  7. Frog: The Fast & Realistic OpenGL Event Displayer

    CERN Document Server

    Quertenmont, Loic

    2009-01-01

    FROG [1] is a generic framework dedicated to visualisation of events in high energy experiment. It is suitable for any particular physics experiment or detector design. The code is light ($<3~\\textrm{MB}$) and fast (browsing time $\\sim20$ events per second for a large High Energy Physics experiment) and can run on various operating systems, as its object-oriented structure (C++) relies on the cross-platform OpenGL[2] and GLUT [3] libraries. Moreover, \\textsc{Frog} does not require installation of third party libraries for the visualisation. This documents describes the features and principles of FROG version 1.106, its working scheme and numerous functionalities such as: 3D and 2D visualisation, graphical user interface, mouse interface, configuration files, production of pictures of various format, integration of personal objects, etc. Finally, several examples of its current applications are presented for illustration.

  8. Voxel-based frog phantom for internal dose evaluation

    International Nuclear Information System (INIS)

    Kinase, Sakae

    2008-01-01

    A voxel-based frog phantom has been developed for radiation protection of the environment. The voxel-based frog phantom was applied to evaluating self-absorbed fractions (self-AFs), which are defined as the fraction of energy emitted by a radiation source that is absorbed within the source organ. The self-AFs were evaluated for both photons and electrons in the spleen, kidneys, and liver using Monte Carlo simulations. Furthermore, self-S values (μGy/MBq·s) for 18 F and 90 Y in the organs were calculated using the results of the self-AFs. Consequently, the voxel-based frog phantom was found to be useful for the organ dose evaluations, which have not been proposed by the International Commission on Radiological Protection (ICRP). It was also confirmed that the self-AFs and self-S values are largely dependent on the mass of the source organ. (author)

  9. Slow growth rates of Amazonian trees: Consequences for carbon cycling

    Science.gov (United States)

    Vieira, Simone; Trumbore, Susan; Camargo, Plinio B.; Selhorst, Diogo; Chambers, Jeffrey Q.; Higuchi, Niro; Martinelli, Luiz Antonio

    2005-01-01

    Quantifying age structure and tree growth rate of Amazonian forests is essential for understanding their role in the carbon cycle. Here, we use radiocarbon dating and direct measurement of diameter increment to document unexpectedly slow growth rates for trees from three locations spanning the Brazilian Amazon basin. Central Amazon trees, averaging only ≈1mm/year diameter increment, grow half as fast as those from areas with more seasonal rainfall to the east and west. Slow growth rates mean that trees can attain great ages; across our sites we estimate 17-50% of trees with diameter >10 cm have ages exceeding 300 years. Whereas a few emergent trees that make up a large portion of the biomass grow faster, small trees that are more abundant grow slowly and attain ages of hundreds of years. The mean age of carbon in living trees (60-110 years) is within the range of or slightly longer than the mean residence time calculated from C inventory divided by annual C allocation to wood growth (40-100 years). Faster C turnover is observed in stands with overall higher rates of diameter increment and a larger fraction of the biomass in large, fast-growing trees. As a consequence, forests can recover biomass relatively quickly after disturbance, whereas recovering species composition may take many centuries. Carbon cycle models that apply a single turnover time for carbon in forest biomass do not account for variations in life strategy and therefore may overestimate the carbon sequestration potential of Amazon forests. PMID:16339903

  10. Environmental characteristics drive variation in Amazonian understorey bird assemblages.

    Directory of Open Access Journals (Sweden)

    Juliana Menger

    Full Text Available Tropical bird assemblages display patterns of high alpha and beta diversity and, as tropical birds exhibit strong habitat specificity, their spatial distributions are generally assumed to be driven primarily by environmental heterogeneity and interspecific interactions. However, spatial distributions of some Amazonian forest birds are also often restricted by large rivers and other large-scale topographic features, suggesting that dispersal limitation may also play a role in driving species' turnover. In this study, we evaluated the effects of environmental characteristics, topographic and spatial variables on variation in local assemblage structure and diversity of birds in an old-growth forest in central Amazonia. Birds were mist-netted in 72 plots distributed systematically across a 10,000 ha reserve in each of three years. Alpha diversity remained stable through time, but species composition changed. Spatial variation in bird-assemblage structure was significantly related to environmental and topographic variables but not strongly related to spatial variables. At a broad scale, we found bird assemblages to be significantly distinct between two watersheds that are divided by a central ridgeline. We did not detect an effect of the ridgeline per se in driving these patterns, indicating that most birds are able to fly across it, and that differences in assemblage structure between watersheds may be due to unmeasured environmental variables or unique combinations of measured variables. Our study indicates that complex geography and landscape features can act together with environmental variables to drive changes in the diversity and composition of tropical bird assemblages at local scales, but highlights that we still know very little about what makes different parts of tropical forest suitable for different species.

  11. Life history and environment of Cecropia latiloba in Amazonian floodplains.

    Science.gov (United States)

    Parolin, Pia

    2002-06-01

    Cecropia latiloba can be considered to be one of the most efficient colonizers of open areas in the nutrient-rich whitewater floodplains of the Amazon river. Its main strategy to be successful is the high tolerance towards waterlogging and submergence, and the fast vertical growth and reiteration capacity. This, and the tolerance of high irradiation and sediment deposition allow C. latiloba to form large monospecific stands on open sites, and thus the first closed canopy which represents the initial phase of a successional sequence which leads to highly diverse forests. This tree is extremely well adapted to the adverse growth conditions in Amazonian floodplains with prolonged periods of flooding and seedling submergence. The species occurs on the lowest levels in the flooding gradient. Although it belongs to the most often cited species under aspects of taxonomy, species distribution and general descriptions of the ecosystem, little has been published about its ecology. In the present paper the ecological, physiological and phenological characteristics of C. latiloba are described. It is an evergreen species which constantly produces new leaves. With flooding, leaf production is reduced but new leaves are flushed also with prolongued flooding. The peak of flowering and fruiting are in the flooded period. When mature, the fruits are dispersed mainly by water and fish. Seed germination occurs, without dormancy, within 5-13 days after water retreat. In the 7 months before the first flooded period seedlings reach 1 m of height, and height growth increases until 15-20 m are achieved. Photosynthetic assimilation is high, with values of up to 21 mumol CO2 m-2s-1. C. latiloba is a very flood tolerant species, and waterlogged seedlings continuously produce new leaves and adventitious roots.

  12. Thresholds of species loss in Amazonian deforestation frontier landscapes.

    Science.gov (United States)

    Ochoa-Quintero, Jose Manuel; Gardner, Toby A; Rosa, Isabel; Ferraz, Silvio Frosini de Barros; Sutherland, William J

    2015-04-01

    In the Brazilian Amazon, private land accounts for the majority of remaining native vegetation. Understanding how land-use change affects the composition and distribution of biodiversity in farmlands is critical for improving conservation strategies in the face of rapid agricultural expansion. Working across an area exceeding 3 million ha in the southwestern state of Rondônia, we assessed how the extent and configuration of remnant forest in replicate 10,000-ha landscapes has affected the occurrence of a suite of Amazonian mammals and birds. In each of 31 landscapes, we used field sampling and semistructured interviews with landowners to determine the presence of 28 large and medium sized mammals and birds, as well as a further 7 understory birds. We then combined results of field surveys and interviews with a probabilistic model of deforestation. We found strong evidence for a threshold response of sampled biodiversity to landscape level forest cover; landscapes with deforested landscapes many species are susceptible to extirpation following relatively small additional reductions in forest area. In the model of deforestation by 2030 the number of 10,000-ha landscapes under a conservative threshold of 43% forest cover almost doubled, such that only 22% of landscapes would likely to be able to sustain at least 75% of the 35 focal species we sampled. Brazilian law requires rural property owners in the Amazon to retain 80% forest cover, although this is rarely achieved. Prioritizing efforts to ensure that entire landscapes, rather than individual farms, retain at least 50% forest cover may help safeguard native biodiversity in private forest reserves in the Amazon. © 2015 Society for Conservation Biology.

  13. Lizard and frog prestin: evolutionary insight into functional changes.

    Directory of Open Access Journals (Sweden)

    Jie Tang

    Full Text Available The plasma membrane of mammalian cochlear outer hair cells contains prestin, a unique motor protein. Prestin is the fifth member of the solute carrier protein 26A family. Orthologs of prestin are also found in the ear of non-mammalian vertebrates such as zebrafish and chicken. However, these orthologs are electrogenic anion exchangers/transporters with no motor function. Amphibian and reptilian lineages represent phylogenic branches in the evolution of tetrapods and subsequent amniotes. Comparison of the peptide sequences and functional properties of these prestin orthologs offer new insights into prestin evolution. With the recent availability of the lizard and frog genome sequences, we examined amino acid sequence and function of lizard and frog prestins to determine how they are functionally and structurally different from prestins of mammals and other non-mammals. Somatic motility, voltage-dependent nonlinear capacitance (NLC, the two hallmarks of prestin function, and transport capability were measured in transfected human embryonic kidney cells using voltage-clamp and radioisotope techniques. We demonstrated that while the transport capability of lizard and frog prestin was compatible to that of chicken prestin, the NLC of lizard prestin was more robust than that of chicken's and was close to that of platypus. However, unlike platypus prestin which has acquired motor capability, lizard or frog prestin did not demonstrate motor capability. Lizard and frog prestins do not possess the same 11-amino-acid motif that is likely the structural adaptation for motor function in mammals. Thus, lizard and frog prestins appear to be functionally more advanced than that of chicken prestin, although motor capability is not yet acquired.

  14. The Maluti Mystery revisited: Taxonomy of African River Frogs (Pyxicephalidae, Amietia) on the Drakensberg Mountains in southern Africa.

    Science.gov (United States)

    Channing, Alan

    2015-02-27

    The taxonomy of two similar frogs from the top of the Drakensberg escarpment, the Maluti River Frog and the Phofung River Frog is not settled. I examine the relevant types and type descriptions, and discover a number of errors in the literature. Some of the recent taxonomic changes were found to be unsupported. The Maluti River Frog is assigned to Amietia vertebralis (Hewitt, 1927), and the Phofung River Frog to Amietia hymenopus (Boulenger, 1920).

  15. Ant and Mite Diversity Drives Toxin Variation in the Little Devil Poison Frog.

    Science.gov (United States)

    McGugan, Jenna R; Byrd, Gary D; Roland, Alexandre B; Caty, Stephanie N; Kabir, Nisha; Tapia, Elicio E; Trauger, Sunia A; Coloma, Luis A; O'Connell, Lauren A

    2016-06-01

    Poison frogs sequester chemical defenses from arthropod prey, although the details of how arthropod diversity contributes to variation in poison frog toxins remains unclear. We characterized skin alkaloid profiles in the Little Devil poison frog, Oophaga sylvatica (Dendrobatidae), across three populations in northwestern Ecuador. Using gas chromatography/mass spectrometry, we identified histrionicotoxins, 3,5- and 5,8-disubstituted indolizidines, decahydroquinolines, and lehmizidines as the primary alkaloid toxins in these O. sylvatica populations. Frog skin alkaloid composition varied along a geographical gradient following population distribution in a principal component analysis. We also characterized diversity in arthropods isolated from frog stomach contents and confirmed that O. sylvatica specialize on ants and mites. To test the hypothesis that poison frog toxin variability reflects species and chemical diversity in arthropod prey, we (1) used sequencing of cytochrome oxidase 1 to identify individual prey specimens, and (2) used liquid chromatography/mass spectrometry to chemically profile consumed ants and mites. We identified 45 ants and 9 mites in frog stomachs, including several undescribed species. We also showed that chemical profiles of consumed ants and mites cluster by frog population, suggesting different frog populations have access to chemically distinct prey. Finally, by comparing chemical profiles of frog skin and isolated prey items, we traced the arthropod source of four poison frog alkaloids, including 3,5- and 5,8-disubstituted indolizidines and a lehmizidine alkaloid. Together, the data show that toxin variability in O. sylvatica reflects chemical diversity in arthropod prey.

  16. Divergence among barking frogs (Eleutherodactylus augusti) in the southwestern United States

    Science.gov (United States)

    Goldberg, Caren S.; Sullivan, Brian K.; Malone, John H.; Schwalbe, Cecil R.

    2004-01-01

    Barking frogs (Eleutherodactylus augusti) are distributed from southern Mexico along the Sierra Madre Occidental into Arizona and the Sierra Madre Oriental into Texas and New Mexico. Barking frogs in Arizona and most of Texas live in rocky areas in oak woodland, while those in New Mexico and far western Texas live in rodent burrows in desertscrub. Barking frogs in each of the three states have distinct coloration and differ in sexually dimorphic characters, female vocalization, and skin toxicity. We analyzed advertisement call variation and conducted a phylogenetic analysis using mitochondrial DNA sequences (ND2 and tRNA regions) for barking frogs from these three states. Advertisement calls of frogs from Arizona were significantly longer in duration, higher in frequency, and had longer duration pulses than those of frogs from either New Mexico or Texas; frogs from these latter two sites were indistinguishable in these call variables. Phylogenetic analysis showed deep divisions among barking frogs from the three states. Differences in call structure, coloration, and mitochondrial DNA sequences strongly suggest that barking frogs in Arizona are reproductively isolated from those in New Mexico and Texas. Our results indicate that either northern populations are connected via gene flow through southern Mexico (i.e., they are subspecies as currently recognized), or represent independent lineages as originally described (i.e., western barking frogs, E. cactorum in AZ, and the eastern barking frogs, E. latrans in NM, TX).

  17. Genetic and developmental studies of albino chorus frogs

    Science.gov (United States)

    Corn, Paul Stephen

    1986-01-01

    Albino (amelanic) adult chorus frogs (Pseudacris triseriata) occurred with frequencies of 7 percent in 1981 and 12 percent in 1982 in breeding aggregations at a pond in the foothills of the Colorado Front Range. Laboratory matings and examination of albino egg masses suggest that the absence of melanin is due to a recessive allele. The albino phenotype displayed no deficiencies in survival of embryos, rates of embryo or larval development, or rates of growth of juvenile frogs. The absence of abnormalities in development or growth suggests that the a allele in P. triseriata has an action different from albino alleles studied previously in anurans.

  18. Host Defense Peptides from Asian Frogs as Potential Clinical Therapies

    Science.gov (United States)

    Kumar, Vineeth T.V.; Holthausen, David; Jacob, Joshy; George, Sanil

    2015-01-01

    Host defense peptides (HDPs) are currently major focal points of medical research as infectious microbes are gaining resistance to existing drugs. They are effective against multi-drug resistant pathogens due to their unique primary target, biological membranes, and their peculiar mode of action. Even though HDPs from 60 Asian frog species belonging to 15 genera have been characterized, research into these peptides is at a very early stage. The purpose of this review is to showcase the status of peptide research in Asia. Here we provide a summary of HDPs from Asian frogs. PMID:27025618

  19. Effect of ionizing radiation on cell death in frog spleen

    International Nuclear Information System (INIS)

    Afonin, V.Yu.; Vojtovich, A.M.

    1998-01-01

    It was studied the number of dead cells in frog spleen by means of coloration with trypan blue which allowed to estimate last stage of apoptosis dead of cells.The investigated frogs (Rana arvalis) were caught in september 1997 at radionuclide contamination territory (the Gomel Region, the Khojniki District). Control animals were caught in village Ratamka of the Minsk District. The percent of dead cells was less in control group in 1,5 times. Under additional irradiation (2 Gy) the number of dead cells in spleen also differs significantly in the investigated and control groups

  20. Behavior of Japanese tree frogs under microgravity on MIR and in parabolic flight

    Science.gov (United States)

    Izumi-Kurotani, A.; Yamashita, M.; Kawasaki, Y.; Kurotani, T.; Mogami, Y.; Okuno, M.; Oketa, A.; Shiraishi, A.; Ueda, K.; Wassersug, R. J.; Naitoh, T.

    1994-08-01

    Japanese tree frogs (Hyla japonica) were flown to the space station MIR and spent eight days in orbit during December, 1990/1/. Under microgravity, their postures and behaviors were observed and recorded. On the MIR, floating frogs stretched four legs out, bent their bodies backward and expanded their abdomens. Frogs on a surface often bent their neck backward and walked backwards. This behavior was observed on parabolic flights and resembles the retching behavior of sick frogs on land- a possible indicator of motion sickness. Observations on MIR were carried out twice to investigate the frog's adaptation to space. The frequency of failure in landing after a jump decreased in the second observation period. After the frogs returned to earth, readaptation processes were observed. The frogs behaved normally as early as 2.5 hours after landing.

  1. Evolutionary patterns of range size, abundance and species richness in Amazonian angiosperm trees

    Directory of Open Access Journals (Sweden)

    Kyle Dexter

    2016-09-01

    Full Text Available Amazonian tree species vary enormously in their total abundance and range size, while Amazonian tree genera vary greatly in species richness. The drivers of this variation are not well understood. Here, we construct a phylogenetic hypothesis that represents half of Amazonian tree genera in order to contribute to explaining the variation. We find several clear, broad-scale patterns. Firstly, there is significant phylogenetic signal for all three characteristics; closely related genera tend to have similar numbers of species and similar mean range size and abundance. Additionally, the species richness of genera shows a significant, negative relationship with the mean range size and abundance of their constituent species. Our results suggest that phylogenetically correlated intrinsic factors, namely traits of the genera themselves, shape among lineage variation in range size, abundance and species richness. We postulate that tree stature may be one particularly relevant trait. However, other traits may also be relevant, and our study reinforces the need for ambitious compilations of trait data for Amazonian trees. In the meantime, our study shows how large-scale phylogenies can help to elucidate, and contribute to explaining, macroecological and macroevolutionary patterns in hyperdiverse, yet poorly understood regions like the Amazon Basin.

  2. The role of Amazonian anthropogenic soils in shifting cultivation: learning from farmers’ rationales

    NARCIS (Netherlands)

    Braga Junqueira, A.; Almekinders, C.J.M.; Stomph, T.J.; Clement, C.R.; Struik, P.C.

    2016-01-01

    We evaluated farmers’ rationales to understand their decision making in relation to the use of fertile anthropogenic soils, i.e., Amazonian dark earths (ADE), and for dealing with changes in shifting cultivation in Central Amazonia. We analyzed qualitative information from 196 interviews with

  3. Morphology, morphometry and ultrastructure of the Amazonian manatee (Sirenia: Trichechidae spermatozoa

    Directory of Open Access Journals (Sweden)

    Rodrigo S. Amaral

    2010-01-01

    Full Text Available This study describes the morphological, morphometric and ultrastructural characteristics of the Amazonian manatee Trichechus inunguis (Natterer, 1883 spermatozoon. The spermatozoa were obtained from a urine sample of an adult T. inunguis kept in captivity. The spermatozoa were analyzed by light and transmission electron microscopy. The head of Amazonian manatee spermatozoa had a flat oval shape and a well distinguishable midpiece. The mean dimensions of the spermatozoa were: head length, 7.49 ± 0.24 µm; head width, 3.53 ± 0.19 µm; head thickness, 1.61 ± 0.13 µm; midpiece length, 11.36 ± 0.34 µm; flagellum length, 40.91 ± 1.94 µm; total tail length, 52.16 ± 1.06 µm; total spermatozoon length, 60.08 ± 1.40 µm. The Amazonian manatee spermatozoa were similar in shape to other sirenian spermatozoa; however, presenting a different size. This study describes, for the first time, the morphometric and ultrastructural characteristics of the Amazonian manatee spermatozoa, and also demonstrates the possible use of spermatozoa retrieved from urine samples for biological studies.

  4. Legacies of Amazonian dark earths on forest composition, structure and dynamics

    NARCIS (Netherlands)

    Quintero Vallejo, E.M.

    2015-01-01

    Summary

    Amazonian forest is seen as the archetype of pristine forests, untouched by humans, but this romantic view is far from reality. In recent years, there is increasing evidence of long and extensive landscape modification by humans. Processes of permanent inhabitation,

  5. Notes on Amazonian Bittacidae (Mecoptera with the descriptions of two new species

    Directory of Open Access Journals (Sweden)

    Norman D. Penny

    1982-09-01

    Full Text Available New species of Issikiella and Nannobittacus are described and notes are presented on other Amazonian species of Mecoptera.Nova espécie de Issikiella e Nannobittacus são descritas e notas são apresentadas para outras espécies de Mecopteros da Amazônia.

  6. Effects of reduced-impact logging and forest physiognomy on bat populations of lowland Amazonian forest.

    Science.gov (United States)

    Steven J. Presley; Michael R. Willig; Wunderle Jr. Joseph M.; Luis Nélio. Saldanha

    2008-01-01

    1.As human population size increases, demand for natural resources will increase. Logging pressure related to increasing demands continues to threaten remote areas of Amazonian forest. A harvest protocol is required to provide renewable timber resources that meet consumer needs while minimizing negative effects on biodiversity and ecosystem services. Reduced-impact...

  7. Legacies of Amazonian dark earths on forest composition, structure and dynamics

    NARCIS (Netherlands)

    Quintero Vallejo, E.M.

    2015-01-01

    Summary

    Amazonian forest is seen as the archetype of pristine forests, untouched by humans, but this romantic view is far from reality. In recent years, there is increasing evidence of long and extensive landscape modification by humans. Processes of permanent inhabitation,

  8. The development of the Amazonian mega-wetland (Miocene; Brazil, Colombia, Peru, Bolivia)

    NARCIS (Netherlands)

    Hoorn, C.; Wesselingh, F.P.; Hovikoski, J.; Guerrero, J.; Hoorn, C.; Wesselingh, F.P.

    2010-01-01

    The scenery of Western Amazonia once consisted of fluvial systems that originated on the Amazonian Craton and were directed towards the sub-Andean zone and the Caribbean. In the course of the Early Miocene these fluvial systems were largely replaced by lakes, swamps, tidal channels and marginal

  9. Amazonian Dark Earth and its Black Carbon Particles Harbor Different Fungal Abundance and Diversity

    NARCIS (Netherlands)

    Reis Lucheta, Adriano; Souza Cannavan, F.S.; Tsai, S.M.; Kuramae, E.E.

    2017-01-01

    Amazonian Dark Earth (ADE) is a highly fertile soil of anthropogenic origin characterized by higher amount of charred black carbon (BC). ADE is considered a fertility model, however knowledge about the fungal community structure and diversity inhabiting ADE and BC is scarce. Fungal community

  10. Amazonian Dark Earth and plant species from the Amazon region contribute to shape rhizosphere bacterial communities

    NARCIS (Netherlands)

    Barbosa Lima, A.; Souza Cannavan, F.S.; Navarrete, A.A.; Kuramae, E.E.; Teixeira, W.G.; Tsai, S.M.

    2015-01-01

    Amazonian Dark Earths (ADE) or Terra Preta de Índio formed in the past by pre-Columbian populations are highly sustained fertile soils supported by microbial communities that differ from those extant in adjacent soils. These soils are found in the Amazon region and are considered as a model soil

  11. High levels of diversity uncovered in a widespread nominal taxon: continental phylogeography of the neotropical tree frog Dendropsophus minutus.

    Science.gov (United States)

    Gehara, Marcelo; Crawford, Andrew J; Orrico, Victor G D; Rodríguez, Ariel; Lötters, Stefan; Fouquet, Antoine; Barrientos, Lucas S; Brusquetti, Francisco; De la Riva, Ignacio; Ernst, Raffael; Urrutia, Giuseppe Gagliardi; Glaw, Frank; Guayasamin, Juan M; Hölting, Monique; Jansen, Martin; Kok, Philippe J R; Kwet, Axel; Lingnau, Rodrigo; Lyra, Mariana; Moravec, Jiří; Pombal, José P; Rojas-Runjaic, Fernando J M; Schulze, Arne; Señaris, J Celsa; Solé, Mirco; Rodrigues, Miguel Trefaut; Twomey, Evan; Haddad, Celio F B; Vences, Miguel; Köhler, Jörn

    2014-01-01

    Species distributed across vast continental areas and across major biomes provide unique model systems for studies of biotic diversification, yet also constitute daunting financial, logistic and political challenges for data collection across such regions. The tree frog Dendropsophus minutus (Anura: Hylidae) is a nominal species, continentally distributed in South America, that may represent a complex of multiple species, each with a more limited distribution. To understand the spatial pattern of molecular diversity throughout the range of this species complex, we obtained DNA sequence data from two mitochondrial genes, cytochrome oxidase I (COI) and the 16S rhibosomal gene (16S) for 407 samples of D. minutus and closely related species distributed across eleven countries, effectively comprising the entire range of the group. We performed phylogenetic and spatially explicit phylogeographic analyses to assess the genetic structure of lineages and infer ancestral areas. We found 43 statistically supported, deep mitochondrial lineages, several of which may represent currently unrecognized distinct species. One major clade, containing 25 divergent lineages, includes samples from the type locality of D. minutus. We defined that clade as the D. minutus complex. The remaining lineages together with the D. minutus complex constitute the D. minutus species group. Historical analyses support an Amazonian origin for the D. minutus species group with a subsequent dispersal to eastern Brazil where the D. minutus complex originated. According to our dataset, a total of eight mtDNA lineages have ranges >100,000 km2. One of them occupies an area of almost one million km2 encompassing multiple biomes. Our results, at a spatial scale and resolution unprecedented for a Neotropical vertebrate, confirm that widespread amphibian species occur in lowland South America, yet at the same time a large proportion of cryptic diversity still remains to be discovered.

  12. High levels of diversity uncovered in a widespread nominal taxon: continental phylogeography of the neotropical tree frog Dendropsophus minutus.

    Directory of Open Access Journals (Sweden)

    Marcelo Gehara

    Full Text Available Species distributed across vast continental areas and across major biomes provide unique model systems for studies of biotic diversification, yet also constitute daunting financial, logistic and political challenges for data collection across such regions. The tree frog Dendropsophus minutus (Anura: Hylidae is a nominal species, continentally distributed in South America, that may represent a complex of multiple species, each with a more limited distribution. To understand the spatial pattern of molecular diversity throughout the range of this species complex, we obtained DNA sequence data from two mitochondrial genes, cytochrome oxidase I (COI and the 16S rhibosomal gene (16S for 407 samples of D. minutus and closely related species distributed across eleven countries, effectively comprising the entire range of the group. We performed phylogenetic and spatially explicit phylogeographic analyses to assess the genetic structure of lineages and infer ancestral areas. We found 43 statistically supported, deep mitochondrial lineages, several of which may represent currently unrecognized distinct species. One major clade, containing 25 divergent lineages, includes samples from the type locality of D. minutus. We defined that clade as the D. minutus complex. The remaining lineages together with the D. minutus complex constitute the D. minutus species group. Historical analyses support an Amazonian origin for the D. minutus species group with a subsequent dispersal to eastern Brazil where the D. minutus complex originated. According to our dataset, a total of eight mtDNA lineages have ranges >100,000 km2. One of them occupies an area of almost one million km2 encompassing multiple biomes. Our results, at a spatial scale and resolution unprecedented for a Neotropical vertebrate, confirm that widespread amphibian species occur in lowland South America, yet at the same time a large proportion of cryptic diversity still remains to be discovered.

  13. High Levels of Diversity Uncovered in a Widespread Nominal Taxon: Continental Phylogeography of the Neotropical Tree Frog Dendropsophus minutus

    Science.gov (United States)

    Gehara, Marcelo; Crawford, Andrew J.; Orrico, Victor G. D.; Rodríguez, Ariel; Lötters, Stefan; Fouquet, Antoine; Barrientos, Lucas S.; Brusquetti, Francisco; De la Riva, Ignacio; Ernst, Raffael; Urrutia, Giuseppe Gagliardi; Glaw, Frank; Guayasamin, Juan M.; Hölting, Monique; Jansen, Martin; Kok, Philippe J. R.; Kwet, Axel; Lingnau, Rodrigo; Lyra, Mariana; Moravec, Jiří; Pombal, José P.; Rojas-Runjaic, Fernando J. M.; Schulze, Arne; Señaris, J. Celsa; Solé, Mirco; Rodrigues, Miguel Trefaut; Twomey, Evan; Haddad, Celio F. B.; Vences, Miguel; Köhler, Jörn

    2014-01-01

    Species distributed across vast continental areas and across major biomes provide unique model systems for studies of biotic diversification, yet also constitute daunting financial, logistic and political challenges for data collection across such regions. The tree frog Dendropsophus minutus (Anura: Hylidae) is a nominal species, continentally distributed in South America, that may represent a complex of multiple species, each with a more limited distribution. To understand the spatial pattern of molecular diversity throughout the range of this species complex, we obtained DNA sequence data from two mitochondrial genes, cytochrome oxidase I (COI) and the 16S rhibosomal gene (16S) for 407 samples of D. minutus and closely related species distributed across eleven countries, effectively comprising the entire range of the group. We performed phylogenetic and spatially explicit phylogeographic analyses to assess the genetic structure of lineages and infer ancestral areas. We found 43 statistically supported, deep mitochondrial lineages, several of which may represent currently unrecognized distinct species. One major clade, containing 25 divergent lineages, includes samples from the type locality of D. minutus. We defined that clade as the D. minutus complex. The remaining lineages together with the D. minutus complex constitute the D. minutus species group. Historical analyses support an Amazonian origin for the D. minutus species group with a subsequent dispersal to eastern Brazil where the D. minutus complex originated. According to our dataset, a total of eight mtDNA lineages have ranges >100,000 km2. One of them occupies an area of almost one million km2 encompassing multiple biomes. Our results, at a spatial scale and resolution unprecedented for a Neotropical vertebrate, confirm that widespread amphibian species occur in lowland South America, yet at the same time a large proportion of cryptic diversity still remains to be discovered. PMID:25208078

  14. Understanding moisture recycling for atmospheric river management in Amazonian communities

    Science.gov (United States)

    Weng, Wei; Luedeke, Matthias; Zemp, Delphine-Clara; Lakes, Tobia; Pradhan, Prajal; Kropp, Juergen

    2017-04-01

    The invisible atmospheric transports of moisture have recently attracted more research efforts into understanding their structures, processes involved and their function as an ecosystem service. Current attention has been focused on larger scale analysis such as studying global or continental level moisture recycling. Here we applied a water balance model to backtrack the flying river that sustains two local communities in the Colombian and Peruvian Amazon where vulnerable communities rely highly on the rainfall for agricultural practices. By utilising global precipitation (TRMM Multisatillite Precipitation Analysis; TMPA) and evapotranspiration products (Moderate Resolution Imaging Spectroradiometer MODIS, MOD16ET) as input data in the present modelling experiments to compensate the sparse ground observation data in these regions, the moisture recycling process targeting the two amazonian communities which has not yet been explored quantitatively has been shown. The TMPA was selected because of its proved comparativeness with observation data in its precipitation estimations over Amazon regions while the MOD16ET data was chosen for being validated by previous studies in the Amazon basin and for reported good performance. In average, 45.5 % of the precipitation occurring to Caquetá region in Colombia is of terrestrial origin from the South American continent while 48.2% of the total rainfall received by Peruvian Yurimaguas is also from the South American land sources. The spatial distribution of the precipitationsheds (defined previously as the upwind contribution of evapotranspiration to a specific location's precipitation) shows transboundary and transnational shares in the moisture contributors of the precipitation for both regions. An interesting reversed upstream-downstream roles can be observed when the upstream regions in traditional watershed thinking become downstream areas considering precipitationsheds and flying rivers. Strong seasonal variations are

  15. Helminths of the two mountain frogs, banded frog, Rana camerani Boulenger, 1886 and Uludağ frog Rana macrocnemis Boulenger, 1885 (Anura: Ranidae), collected from the Antalya province.

    Science.gov (United States)

    Düşen, Serdar

    2007-01-01

    In this study, two mountain frogs (Rana camerani and Rana macrocnemis) were collected in the Antalya Province in south-western Turkey during 2001 and 2002 and were examined for helminths. Out of 15 Rana camerani, 10 (66.7%) were infected with 1 or more helminths and out of 20 Rana macrocnemis, 17 (85%) were infected with 1 or more helminths. The helminth fauna of Rana camerani included 4 species of which were 3 trematode species (Haplometra cylindracea, Pleurogenoides medians, Opisthioglyphe rastellus), and 1 nematode species (Cosmocerca ornata). The helminth fauna of Rana macrocnemis included 3 species with 1 trematode species (H. cylindracea), 1 nematode species (C. ornata), and 1 acanthocephalan species (Acanthocephalus ranae). H. cylindracea and C. ornata were observed in both of the mountain frogs.

  16. Measurement and Evaluation of Wear Frogs Switches ŽSR

    Directory of Open Access Journals (Sweden)

    Urda Ján

    2014-05-01

    Full Text Available This paper deals with the measurement and evaluation of wear frogs switches ZSR. One of the main problems is the oversize wear. The possibilities analysis of this problem is offered through a set of switches and monitoring of selected parameters. One of these parameters is also monitoring the vertical wear

  17. Choosing the safest route: frog orientation in an agricultural landscape

    NARCIS (Netherlands)

    Mazerolle, M.J.; Vos, C.C.

    2006-01-01

    Orientation is a key component to successful movements between habitats. We hypothesized that barren agricultural landscapes hinder the ability of frogs to orient and move between habitats. Specifically, we predicted that when presented with a choice between a short route through a hostile

  18. Noxious toads and frogs of South Africa | Pantanowitz | South ...

    African Journals Online (AJOL)

    Toad (Bufo and Schismademra pecies), the amphibian with which man and his pets most frequently have contact, secrete potent toxins with cardiac glycoside activity. Topical and systemic intoxication, while seen in humans, remains predominantly a veterinary problem. Intoxication by the red-banded rubber frog, which ...

  19. Research on moving object detection based on frog's eyes

    Science.gov (United States)

    Fu, Hongwei; Li, Dongguang; Zhang, Xinyuan

    2008-12-01

    On the basis of object's information processing mechanism with frog's eyes, this paper discussed a bionic detection technology which suitable for object's information processing based on frog's vision. First, the bionics detection theory by imitating frog vision is established, it is an parallel processing mechanism which including pick-up and pretreatment of object's information, parallel separating of digital image, parallel processing, and information synthesis. The computer vision detection system is described to detect moving objects which has special color, special shape, the experiment indicates that it can scheme out the detecting result in the certain interfered background can be detected. A moving objects detection electro-model by imitating biologic vision based on frog's eyes is established, the video simulative signal is digital firstly in this system, then the digital signal is parallel separated by FPGA. IN the parallel processing, the video information can be caught, processed and displayed in the same time, the information fusion is taken by DSP HPI ports, in order to transmit the data which processed by DSP. This system can watch the bigger visual field and get higher image resolution than ordinary monitor systems. In summary, simulative experiments for edge detection of moving object with canny algorithm based on this system indicate that this system can detect the edge of moving objects in real time, the feasibility of bionic model was fully demonstrated in the engineering system, and it laid a solid foundation for the future study of detection technology by imitating biologic vision.

  20. Pouch brooding marsupial frogs transfer nutrients to developing embryos.

    Science.gov (United States)

    Warne, Robin W; Catenazzi, Alessandro

    2016-10-01

    Marsupial frogs have a unique reproductive mode in which females carry eggs enclosed in a sealed dorsal brood pouch. While most anurans are considered to be oviparous with lecithotrophic eggs, the extensively vascularized membrane of the brood pouch in marsupial frogs suggests potential opportunities for nutrient transfer. We tested for matrotrophy in the live-bearing Gastrotheca excubitor (Hemiphractidae), through feeding insects labelled with a 13 C-fatty acid and a 15 N-amino acid to brooding marsupial frogs. We observed significant increases of δ 13 C and δ 15 N in both maternal pouch tissues and embryos, suggesting nutrient transfer. Embryo dry mass also increased with developmental stage, providing further direct evidence for matrotrophy. These results suggest that in addition to gas exchange, the vascularized brood pouch membrane of G. excubitor also enables maternal nutrient transfer. This finding revealed a suspected but untested trait in the evolution of parental care in marsupial frogs, in contrast to previous work on Gastrotheca species that release tadpoles, and suggests greater complexity in reproductive and provisioning modes than previously thought. © 2016 The Author(s).

  1. A new grass frog from Namibia | Channing | African Zoology

    African Journals Online (AJOL)

    A new species of grass frog of lhe genus Ptychadena is described from northern Namibia. Although superficially similar to Ptychadena schillukorum and Ptychadena mossambica, the new species differs In advertisement call, and external characters. An examination of a series of published sonagrams indicates that ...

  2. Biophysics of underwater hearing in the clawed frog, Xenopus laevis

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, J; Elepfandt, A

    1995-01-01

    Anesthetized clawed frogs (Xenopus laevis) were stimulated with underwater sound and the tympanic disk vibrations were studied using laser vibrometry. The tympanic disk velocities ranged from 0.01 to 0.5 mm/s (at a sound pressure of 2 Pa) in the frequency range of 0.4-4 kHz and were 20-40 dB higher...

  3. Antifungal activity of epithelial secretions from selected frog species ...

    African Journals Online (AJOL)

    This study aimed to investigate the antifungal activity of skin secretions from selected frogs (Amietia fuscigula, Strongylopus grayi and Xenopus laevis) and one toad (Amietophrynus pantherinus) of the south Western Cape Province of South Africa. Initially, different extraction techniques for the collection of skin secretions ...

  4. Vectorcardiogram of the 'Man-Frog' | Skowron | South African ...

    African Journals Online (AJOL)

    Chest electrodes from a man and from a frog are connected simultaneously to an oscilloscope - the one to the vertical and the other to the horizontal plates - and the resulting display observed. It consists of a loop, the interpretation of which is discussed, and the conclusion is reached that the presently held vector theory ...

  5. Macro and Trace Element Accumulation in Edible Crabs and Frogs ...

    African Journals Online (AJOL)

    The tissue accumulation of five macroelements (Na, Mg, K, Ca, Fe) and twelve trace elements (Vd, Mn, Co, Ni, Cu, Zn, As, Se, Mo, Ag, Cd, Pb) were assessed in the organs of the edible frogs; Xenopus laevis and Rana esculentus, and whole body of the crab, Callinestes caught from Alaro Stream Floodplain (Ibadan, ...

  6. Ranavirus in wild edible frogs Pelophylax kl. esculentus in Denmark

    DEFF Research Database (Denmark)

    Ariel, Ellen; Kielgast, Jos; Svart, Hans Erik

    2009-01-01

    interviewed by phone and 10 cases were examined on suspicion of diseaseinduced mortality. All samples were negative for Bd. Ranavirus was isolated from 2 samples of recently dead frogs collected during a mass mortality event in an artificial pond near Slagelse, Denmark. The identity of the virus was confirmed...

  7. One-tone suppression in the frog auditory nerve

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, J; Jørgensen, M B

    1996-01-01

    frequencies ranged from 700 to 1200 Hz. Spontaneous activities for the fibers showing one-tone suppression ranged from 3 to 75 spikes/s. Spontaneous activities above 40 spikes/s and the phenomenon of one-tone suppression itself has not been reported previously for frogs. The population of fibers showing one...

  8. Alkaloids from Australian frogs (Myobatrachidae): pseudophrynamines and pumiliotoxins.

    Science.gov (United States)

    Daly, J W; Garraffo, H M; Pannell, L K; Spande, T F; Severini, C; Erspamer, V

    1990-01-01

    Australian frogs of the genus Pseudophryne contain two distinct classes of alkaloids. The pseudophrynamine class (3a-prenyl pyrrolo[2,3-b]indoles) are unique to this genus of frogs of the family Myobatrachidae, while the pumiliotoxin-A class (8-hydroxy-8-methyl-6-alkylidene-1-azabicyclo[4.3.0]nonanes) also occur in dendrobatid frogs of the genera Dendrobates, Epipedobates, and Minyobates, in ranid frogs of the genus Mantella, and in bufonid toads of the genus Melanophryniscus. All seven species of Pseudophryne examined contain both classes of alkaloids. The pseudophrynamines were the predominant class in both species (Pseudophryne guentheri and Pseudophryne occidentalis) from Western Australia, while all of the eastern species (Pseudophryne australis, Pseudophryne bibronii, Pseudophryne coriacea, Pseudophryne corroboree, and Pseudophryne semimarmorata) contained significant amounts of both pseudophrynamines and pumiliotoxins. Pumiliotoxins, in particular pumiliotoxin B, were predominant in two eastern species (P. australis and a southern population of P. corroboree), while pseudophrynamines were dominant in P. bibronii, four of six populations of P. coriacea, one population of P. semimarmorata, and a northern population of P. corroboree. Structures are proposed for several new alkaloids of the pseudophrynamine class.

  9. WEAKLY SYNCHRYRONIZED SUBPOPULATION DYNAMICS IN WISCONSIN FROGS AND TOADS

    Science.gov (United States)

    Spatial synchrony in population dynamics is a topic of increasing interest in basic and applied ecology. We used data from 18 years of frog and toad calling surveys conducted throughout Wisconsin to determine the level of intraspecific synchrony among survey sites, and the relat...

  10. How Can We Tell if Frogs Jump Further?

    Science.gov (United States)

    Drummond, Gordon B.; Tom, Brian D. M.

    2011-01-01

    How effective is training frogs to jump? This is perhaps the most frequent question in biology that is subjected to statistical analysis: does a treatment make a difference? One can examine whether there is indeed a training effect, by first assuming the opposite. That is, the authors assume that training has no effect on the mean distance jumped.…

  11. Foraging behaviour in tadpoles of the bronze frog Rana temporalis ...

    Indian Academy of Sciences (India)

    Unknown

    [Veeranagoudar D K, Shanbhag B A and Saidapur S K 2004 Foraging behaviour in tadpoles of the bronze frog Rana temporalis: Experimental evidence for the ideal free distribution; J. Biosci. 29 201–207]. 1. Introduction. The ecological success of organisms largely depends on their ability to adjust their foraging tactics to ...

  12. Genomic Sequencing of Ranaviruses Isolated from Edible Frogs (Pelophylax esculentus)

    DEFF Research Database (Denmark)

    Ariel, Ellen; Subramaniam, Kuttichantran; Imnoi, Kamonchai

    2017-01-01

    Ranaviruses were isolated from wild edible frogs (Pelophylax esculentus) during epizootics in Denmark and Italy. Phylogenomic analyses revealed that these isolates are closely related and belong to a clade of ranaviruses that includes the Andrias davidianus ranavirus (ADRV), common midwife toad...

  13. Pesticides and Population Declines of California Alpine Frogs

    Science.gov (United States)

    Airborne pesticides from the Central Valley of California have been implicated as a cause for population declines of several amphibian species, with the strongest evidence for the mountain yellow-legged frog complex (Rana muscosa and R. sierrae) in the Sierra Nevada. We measured ...

  14. Antimicrobial peptides from the skins of North American frogs.

    Science.gov (United States)

    Conlon, J Michael; Kolodziejek, Jolanta; Nowotny, Norbert

    2009-08-01

    North America is home to anuran species belonging to the families Bufonidae, Eleutherodactylidae, Hylidae, Leiopelmatidae, Ranidae, and Scaphiopodidae but antimicrobial peptides have been identified only in skin secretions and/or skin extracts of frogs belonging to the Leiopelmatidae ("tailed frogs") and Ranidae ("true frogs"). Eight structurally-related cationic alpha-helical peptides with broad-spectrum antibacterial activity, termed ascaphins, have been isolated from specimens of Ascaphus truei (Leiopelmatidae) occupying a coastal range. Characterization of orthologous antimicrobial peptides from Ascaphus specimens occupying an inland range supports the proposal that this population should be regarded as a separate species A. montanus. Ascaphin-8 shows potential for development into a therapeutically valuable anti-infective agent. Peptides belonging to the brevinin-1, esculentin-1, esculentin-2, palustrin-1, palustrin-2, ranacyclin, ranatuerin-1, ranatuerin-2, and temporin families have been isolated from North American ranids. It is proposed that "ranalexins" represent brevinin-1 peptides that have undergone a four amino acid residue internal deletion. Current taxonomic recommendations divide North American frogs from the family Ranidae into two genera: Lithobates and Rana. Cladistic analysis based upon the amino acid sequences of the brevinin-1 peptides provides strong support for this assignment.

  15. Evidence of auditory insensitivity to vocalization frequencies in two frogs

    DEFF Research Database (Denmark)

    Goutte, Sandra; Mason, Matthew J; Christensen-Dalsgaard, Jakob

    2017-01-01

    The emergence and maintenance of animal communication systems requires the co-evolution of signal and receiver. Frogs and toads rely heavily on acoustic communication for coordinating reproduction and typically have ears tuned to the dominant frequency of their vocalizations, allowing discriminat...

  16. Frogs from the Leeward group, Venezuela and eastern Colombia

    NARCIS (Netherlands)

    Brongersma, L.D.

    1948-01-01

    The present notes deal with a small collection of frogs that was made by Dr. P. WAGENAAR HUMMELINCK during his visits to the islands of the Leeward Group, Venezuela and Eastern Colombia. I have included in this study the specimens of Pleurodema brachyops (Cope) already present in the Rijksmuseum van

  17. Strategies of water conservation in southern African frogs

    African Journals Online (AJOL)

    The most aquatic genus in feeding and locomotion is Xenopus (Van Dijk 1971b), yet even these frogs are known to migrate overland in response to drying of the water (Hewitt & Power 1913;. Loveridge 1953). This phenomenon has been observed in the case of Xenopus laevis in Rhodesia in recent years. On 10 April 1970 ...

  18. Polymorphic microsatellite loci in Chinese piebald odorous frog ...

    Indian Academy of Sciences (India)

    ... for Endangered Wildlife, Ministry of Education, Hangzhou 310058,. People's Republic of China. [Wang Y. and Ding P. 2011 Polymorphic microsatellite loci in Chinese piebald odorous frog (Odorrana schmackeri). J. Genet. 90, e44–e46. Online only: http://www.ias.ac.in/jgenet/OnlineResources/90/e44.pdf]. Introduction.

  19. Colour patterning in the skin of the reed-frog

    African Journals Online (AJOL)

    1985-12-08

    Dec 8, 1985 ... A collec1ion 01 37 Natal reed·frogs, HyperoJius marmoratus, from a single locality was studied for their dorsal colour pattems. Data were assembled on the spectrophotometry, the structure and distribution of ttie chromato· phores by means of light and electron microscopy, and the features of colour ...

  20. Drying kinetics of pre-osmosed fresh water frog ( Dicroglossus ...

    African Journals Online (AJOL)

    The drying kinetics of frog (Dicroglossus occipitalis) was conducted using convective oven dryer. The results were fitted into three thin-layer models; Lewis, Henderson and Page models. The constants and coefficients of the various models used were evaluated using non-linear regression methods, and the results show that ...

  1. Habitat use and spatial structure of a barking frog (Eleutherodactylus augusti) population in southeastern Arizona

    Science.gov (United States)

    Goldberg, C.S.; Schwalbe, C.R.

    2004-01-01

    Barking Frogs (Eleutherodactylus augusti) are the northernmost ranging member of the large tropical family Leptodactylidae. We investigated the ecology of this saxicolous species at the northern edge of its range in a canyon in southern Arizona. We captured 54 frogs on discontinuous rock outcrops; eight of nine females and 39 of 45 males were on limestone outcrops. The remaining frogs were closer to limestone outcrops by more than 200 m than would be expected if they were distributed randomly with respect to limestone formations. Seven of 10 frogs radio-tracked had core home ranges (50% fixed kernel) from 94 to 100% on limestone; the other three frogs did not have any part of their home range on limestone outcrops. During five years of mark-recapture efforts, no frogs were found on a different outcrop from the one where they were originally captured; no radio-tracked frogs moved between outcrops during the breeding season. We estimated that four to 20 Barking Frogs occupied each outcrop; these groups probably are connected primarily by juvenile dispersal. As an organism living at the edge of its range, Barking Frogs in Arizona may rely heavily on extensive underground areas such as those found in limestone to protect them from a physiologically challenging environment. To manage for the persistence of Barking Frogs in southern Arizona, we must identify and protect habitat patches and movement pathways among them.

  2. Cryoprotectant Production in Freeze-Tolerant Wood Frogs Is Augmented by Multiple Freeze-Thaw Cycles.

    Science.gov (United States)

    Larson, Don J; Barnes, Brian M

    2016-01-01

    Ice nucleation across the skin of wood frogs (Lithobates sylvaticus) rapidly induces endogenous production of glucose, a cryoprotectant necessary for freeze tolerance. In laboratory studies of freeze tolerance, wood frogs are cooled slowly, often at -0.05°C h(-1), to facilitate high cryoprotectant production and survival. Under natural conditions in Alaska, however, wood frogs accumulate maximal tissue glucose concentrations while cooling at much faster rates, -0.35° to -1.6°C h(-1), and in addition undergo multiple successive freeze-thaw cycles before remaining frozen for the winter. We examined whether simulating these ecologically relevant cooling rates and repeated freeze-thaw events in captive wood frogs results in the high glucose concentrations found in naturally frozen wood frogs. We found that over successive freezing and thawing events, glucose concentrations increased stepwise in all measured tissues. Short thawing periods did not result in a statistically significant decline of glucose concentrations. Wood frogs that experienced three freeze-thaw events had fresh weight glucose concentrations that approached values found in tissues of wood frogs frozen in natural conditions. Laboratory wood frogs survive frozen for 2 mo, while wood frogs frozen under natural conditions survive frozen for up to 7 mo at temperatures below -18°C. We hypothesize that repeated freeze-thaw cycles with rapid cooling and warming rates allow for greater survival in Alaskan wood frogs through enhanced cryoprotectant production.

  3. Sequestered Alkaloid Defenses in the Dendrobatid Poison Frog Oophaga pumilio Provide Variable Protection from Microbial Pathogens.

    Science.gov (United States)

    Hovey, Kyle J; Seiter, Emily M; Johnson, Erin E; Saporito, Ralph A

    2018-02-10

    Most amphibians produce their own defensive chemicals; however, poison frogs sequester their alkaloid-based defenses from dietary arthropods. Alkaloids function as a defense against predators, and certain types appear to inhibit microbial growth. Alkaloid defenses vary considerably among populations of poison frogs, reflecting geographic differences in availability of dietary arthropods. Consequently, environmentally driven differences in frog defenses may have significant implications regarding their protection against pathogens. While natural alkaloid mixtures in dendrobatid poison frogs have recently been shown to inhibit growth of non-pathogenic microbes, no studies have examined the effectiveness of alkaloids against microbes that infect these frogs. Herein, we examined how alkaloid defenses in the dendrobatid poison frog, Oophaga pumilio, affect growth of the known anuran pathogens Aeromonas hydrophila and Klebsiella pneumoniae. Frogs were collected from five locations throughout Costa Rica that are known to vary in their alkaloid profiles. Alkaloids were isolated from individual skins, and extracts were assayed against both pathogens. Microbe subcultures were inoculated with extracted alkaloids to create dose-response curves. Subsequent spectrophotometry and cell counting assays were used to assess growth inhibition. GC-MS was used to characterize and quantify alkaloids in frog extracts, and our results suggest that variation in alkaloid defenses lead to differences in inhibition of these pathogens. The present study provides the first evidence that alkaloid variation in a dendrobatid poison frog is associated with differences in inhibition of anuran pathogens, and offers further support that alkaloid defenses in poison frogs confer protection against both pathogens and predators.

  4. Body wiping behaviors associated with cutaneous lipids in hylid tree frogs of Florida.

    Science.gov (United States)

    Barbeau, Tamatha R; Lillywhite, Harvey B

    2005-06-01

    Body wiping behavior, integumentary secretions and rates of evaporative water loss (EWL) were examined in six species of Florida tree frogs (Anura: Hylidae). Additionally, morphology of the integument and dermal glands were compared among these and one other Florida tree frog (Hyla andersonii), an arid-adapted tree frog (Phyllomedusa hypochondrialis), and a highly aquatic frog (Rana utricularia). An extra-epidermal layer of lipid and mucus, presumably secreted from dermal granular glands, was detected on the skin of all Florida hylid frogs examined. Distinct body wiping behaviors were observed in the hylid frogs, but these were less complex than those described previously in phyllomedusine frogs, which occupy arid habitats, secrete lipids onto their skin, and are regarded as relatively 'waterproof'. Florida hylids occupy seasonally arid habitats and appear to have reduced rates of EWL. The suite of traits we observed in these frogs have been previously documented in a rhacophorid tree frog from seasonally arid regions of India and likely represent an evolutionary convergent response to periodic dehydration stress. The presence of lipids that are spread by simple wiping behaviors to form an extra-epidermal water barrier may represent an early stage of the more advanced adaptations described in more waterproof arboreal frogs.

  5. COMPARATIVE TOXICITY OF DIURON ON SURVIVAL AND GROWTH OF PACIFIC TREEFROG, BULLFROG, RED-LEGGED FROG, AND AFRICAN CLAWED FROG EMBRYOS AND TADPOLES

    Science.gov (United States)

    The effects of the herbicide diuron on survival and growth of Pacific treefrog (Pseudacris regilla),bullfrog(Rana catesbeiana), red-legged frog(Rana aurora),and African clawed frog(Xenopus laevis)embryos and tadpoles were determined in static-renewal tests. P.regilla and X.laevis...

  6. Spatial and temporal epidemiology of malaria in extra-Amazonian regions of Brazil.

    Science.gov (United States)

    Lorenz, Camila; Virginio, Flávia; Aguiar, Breno S; Suesdek, Lincoln; Chiaravalloti-Neto, Francisco

    2015-10-15

    Mosquitoes, Plasmodium parasites, and humans live in sympatry in some extra-Amazonian regions of Brazil. Recent migrations of people from Amazonia and other countries to extra-Amazonian regions have led to many malaria outbreaks. Lack of relevant expertise among health professionals in non-endemic areas can lead to a neglect of the disease, which can be dangerous given its high fatality rate. Therefore, understanding the spatial and temporal epidemiology of malaria is essential for developing strategies for disease control and elimination. This study aimed to characterize imported (IMP) and autochthonous/introduced (AU/IN) cases in the extra-Amazonian regions and identify risk areas and groups. Epidemiological data collected between 2007 and 2014 were obtained from the Notifiable Diseases Information System of the Ministry of Health (SINAN) and from the Department of the Unified Health System (DATASUS). High malaria risk areas were determined using the Local Indicator of Spatial Association. IMP and AU/IN malaria incidence rates were corrected by Local Empirical Bayesian rates. A total of 6092 malaria cases (IMP: 5416, 88.9 %; AU/IN: 676, 11.1 %) was recorded in the extra-Amazonian regions in 2007-2014. The highest numbers of IMP and AU/IN cases were registered in 2007 (n = 862) and 2010 (n = 149), respectively. IMP cases were more frequent than AU/IN cases in all states except for Espírito Santo. Piauí, Espírito Santo, and Paraná states had high incidences of AU/IN malaria. The majority of infections were by Plasmodium falciparum in northeast and southeast regions, while Plasmodium vivax was the predominant species in the south and mid-west showed cases of dual infection. AU/IN malaria cases were concentrated in the coastal region of Brazil, which contains the Atlantic Forest and hosts the Anopheles transmitters. Several malaria clusters were also associated with the Brazilian Pantanal biome and regions bordering the Amazonian biome. Malaria is widespread

  7. Assessment of radiocesium contamination in frogs 18 months after the Fukushima Daiichi nuclear disaster

    Science.gov (United States)

    Matsushima, Noe; Ihara, Sadao; Takase, Minoru; Horiguchi, Toshihiro

    2015-04-01

    We investigated the accumulation of radionuclides in frogs inhabiting radioactively contaminated areas around Fukushima Daiichi Nuclear Power Plant (FDNPP) to search for possible adverse effects due to radionuclides. We collected 5 frog species and soil samples in areas within and outside a 20-km radius from FDNPP in August and September 2012 and determined their radiocesium concentrations (134Cs and 137Cs). There was a positive correlation between radiocesium concentrations in the soil samples and frogs, and the highest concentration in frogs was 47,278.53 Bq/kg-wet. Although we conducted a histological examination of frog ovaries and testes by light microscopy to detect possible effects of radionuclides on the morphology of germ cells, there were no clear abnormalities in the gonadal tissues of frogs collected from sites with different contamination levels.

  8. Adaptive response in frogs chronically exposed to low doses of ionizing radiation in the environment

    International Nuclear Information System (INIS)

    Audette-Stuart, M.; Kim, S.B.; McMullin, D.; Festarini, A.; Yankovich, T.L.; Carr, J.; Mulpuru, S.

    2011-01-01

    Using the micronucleus assay, decreased levels of DNA damage were found after high dose ionizing radiation exposure of liver cells taken from frogs inhabiting a natural environment with above-background levels of ionizing radiation, compared to cells taken from frogs inhabiting background areas. The data obtained from a small number of animals suggest that stress present in the above-background environment could induce an adaptive response to ionizing radiation. This study did not reveal harmful effects of exposure to low levels of radioactivity. On the contrary, stress present in the above-background area may serve to enhance cellular defense mechanisms. - Highlights: → Frogs were collected from background and higher tritium level habitats. → The micronucleus assay was conducted on liver cells obtained from the frogs. → No detrimental effects were noted in frogs exposed to elevated tritium. → Adaptive responses were observed in frogs exposed to elevated tritium.

  9. Adaptive response in frogs chronically exposed to low doses of ionizing radiation in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Audette-Stuart, M., E-mail: stuartm@aecl.ca [Environmental Technologies Branch, Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, Ontario, K0J 1P0 (Canada); Kim, S.B.; McMullin, D.; Festarini, A.; Yankovich, T.L.; Carr, J.; Mulpuru, S. [Environmental Technologies Branch, Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, Ontario, K0J 1P0 (Canada)

    2011-06-15

    Using the micronucleus assay, decreased levels of DNA damage were found after high dose ionizing radiation exposure of liver cells taken from frogs inhabiting a natural environment with above-background levels of ionizing radiation, compared to cells taken from frogs inhabiting background areas. The data obtained from a small number of animals suggest that stress present in the above-background environment could induce an adaptive response to ionizing radiation. This study did not reveal harmful effects of exposure to low levels of radioactivity. On the contrary, stress present in the above-background area may serve to enhance cellular defense mechanisms. - Highlights: > Frogs were collected from background and higher tritium level habitats. > The micronucleus assay was conducted on liver cells obtained from the frogs. > No detrimental effects were noted in frogs exposed to elevated tritium. > Adaptive responses were observed in frogs exposed to elevated tritium.

  10. Assessment of radiocesium contamination in frogs 18 months after the Fukushima Daiichi nuclear disaster.

    Science.gov (United States)

    Matsushima, Noe; Ihara, Sadao; Takase, Minoru; Horiguchi, Toshihiro

    2015-04-10

    We investigated the accumulation of radionuclides in frogs inhabiting radioactively contaminated areas around Fukushima Daiichi Nuclear Power Plant (FDNPP) to search for possible adverse effects due to radionuclides. We collected 5 frog species and soil samples in areas within and outside a 20-km radius from FDNPP in August and September 2012 and determined their radiocesium concentrations ((134)Cs and (137)Cs). There was a positive correlation between radiocesium concentrations in the soil samples and frogs, and the highest concentration in frogs was 47,278.53 Bq/kg-wet. Although we conducted a histological examination of frog ovaries and testes by light microscopy to detect possible effects of radionuclides on the morphology of germ cells, there were no clear abnormalities in the gonadal tissues of frogs collected from sites with different contamination levels.

  11. Forest structure and carbon dynamics in Amazonian tropical rain forests.

    Science.gov (United States)

    Vieira, Simone; de Camargo, Plinio Barbosa; Selhorst, Diogo; da Silva, Roseana; Hutyra, Lucy; Chambers, Jeffrey Q; Brown, I Foster; Higuchi, Niro; dos Santos, Joaquim; Wofsy, Steven C; Trumbore, Susan E; Martinelli, Luiz Antonio

    2004-08-01

    Living trees constitute one of the major stocks of carbon in tropical forests. A better understanding of variations in the dynamics and structure of tropical forests is necessary for predicting the potential for these ecosystems to lose or store carbon, and for understanding how they recover from disturbance. Amazonian tropical forests occur over a vast area that encompasses differences in topography, climate, and geologic substrate. We observed large differences in forest structure, biomass, and tree growth rates in permanent plots situated in the eastern (near Santarém, Pará), central (near Manaus, Amazonas) and southwestern (near Rio Branco, Acre) Amazon, which differed in dry season length, as well as other factors. Forests at the two sites experiencing longer dry seasons, near Rio Branco and Santarém, had lower stem frequencies (460 and 466 ha(-1) respectively), less biodiversity (Shannon-Wiener diversity index), and smaller aboveground C stocks (140.6 and 122.1 Mg C ha(-1)) than the Manaus site (626 trees ha(-1), 180.1 Mg C ha(-1)), which had less seasonal variation in rainfall. The forests experiencing longer dry seasons also stored a greater proportion of the total biomass in trees with >50 cm diameter (41-45 vs 30% in Manaus). Rates of annual addition of C to living trees calculated from monthly dendrometer band measurements were 1.9 (Manaus), 2.8 (Santarém), and 2.6 (Rio Branco) Mg C ha(-1) year(-1). At all sites, trees in the 10-30 cm diameter class accounted for the highest proportion of annual growth (38, 55 and 56% in Manaus, Rio Branco and Santarém, respectively). Growth showed marked seasonality, with largest stem diameter increment in the wet season and smallest in the dry season, though this may be confounded by seasonal variation in wood water content. Year-to-year variations in C allocated to stem growth ranged from nearly zero in Rio Branco, to 0.8 Mg C ha(-1) year(-1) in Manaus (40% of annual mean) and 0.9 Mg C ha(-1) year(-1) (33% of

  12. A new species of Osteocephalus (Anura: Hylidae) from Amazonian Bolivia: first evidence of tree frog breeding in fruit capsules of the Brazil nut tree

    Czech Academy of Sciences Publication Activity Database

    Moravec, J.; Aparicio, J.; Guerrero-Reinhard, M.; Calderón, G.; Jungfer, K. H.; Gvoždík, Václav

    2009-01-01

    Roč. 2215, - (2009), s. 37-54 ISSN 1175-5326 R&D Projects: GA MŠk LC06073 Institutional research plan: CEZ:AV0Z50450515 Keywords : Amphibia * Anura * Molecular phylogeny Subject RIV: EG - Zoology Impact factor: 0.891, year: 2009

  13. Itraconazole treatment reduces Batrachochytrium dendrobatidis prevalence and increases overwinter field survival in juvenile Cascades frogs.

    Science.gov (United States)

    Hardy, Bennett M; Pope, Karen L; Piovia-Scott, Jonah; Brown, Richard N; Foley, Janet E

    2015-01-15

    The global spread of the fungal pathogen Batrachochytrium dendrobatidis (Bd) has led to widespread extirpation of amphibian populations. During an intervention aimed at stabilizing at-risk populations, we treated wild-caught Cascades frogs Rana cascadae with the antifungal drug itraconazole. In fall 2012, we collected 60 recently metamorphosed R. cascadae from 1 of the 11 remnant populations in the Cascades Mountains (CA, USA). Of these, 30 randomly selected frogs were treated with itraconazole and the other 30 frogs served as experimental controls; all were released at the capture site. Bd prevalence was low at the time of treatment and did not differ between treated frogs and controls immediately following treatment. Following release, Bd prevalence gradually increased in controls but not in treated frogs, with noticeable (but still non-significant) differences 3 wk after treatment (27% [4/15] vs. 0% [0/13]) and strong differences 5 wk after treatment (67% [8/12] vs. 13% [1/8]). We did not detect any differences in Bd prevalence and load between experimental controls and untreated wild frogs during this time period. In spring 2013, we recaptured 7 treated frogs but none of the experimental control frogs, suggesting that over-winter survival was higher for treated frogs. The itraconazole treatment did appear to reduce growth rates: treated frogs weighed 22% less than control frogs 3 wk after treatment (0.7 vs. 0.9 g) and were 9% shorter than control frogs 5 wk after treatment (18.4 vs. 20.2 mm). However, for critically small populations, increased survival of the most at-risk life stage could prevent or delay extinction. Our results show that itraconazole treatment can be effective against Bd infection in wild amphibians, and therefore the beneficial effects on survivorship may outweigh the detrimental effects on growth.

  14. Frog: Asynchronous Graph Processing on GPU with Hybrid Coloring Model

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Xuanhua; Luo, Xuan; Liang, Junling; Zhao, Peng; Di, Sheng; He, Bingsheng; Jin, Hai

    2018-01-01

    GPUs have been increasingly used to accelerate graph processing for complicated computational problems regarding graph theory. Many parallel graph algorithms adopt the asynchronous computing model to accelerate the iterative convergence. Unfortunately, the consistent asynchronous computing requires locking or atomic operations, leading to significant penalties/overheads when implemented on GPUs. As such, coloring algorithm is adopted to separate the vertices with potential updating conflicts, guaranteeing the consistency/correctness of the parallel processing. Common coloring algorithms, however, may suffer from low parallelism because of a large number of colors generally required for processing a large-scale graph with billions of vertices. We propose a light-weight asynchronous processing framework called Frog with a preprocessing/hybrid coloring model. The fundamental idea is based on Pareto principle (or 80-20 rule) about coloring algorithms as we observed through masses of realworld graph coloring cases. We find that a majority of vertices (about 80%) are colored with only a few colors, such that they can be read and updated in a very high degree of parallelism without violating the sequential consistency. Accordingly, our solution separates the processing of the vertices based on the distribution of colors. In this work, we mainly answer three questions: (1) how to partition the vertices in a sparse graph with maximized parallelism, (2) how to process large-scale graphs that cannot fit into GPU memory, and (3) how to reduce the overhead of data transfers on PCIe while processing each partition. We conduct experiments on real-world data (Amazon, DBLP, YouTube, RoadNet-CA, WikiTalk and Twitter) to evaluate our approach and make comparisons with well-known non-preprocessed (such as Totem, Medusa, MapGraph and Gunrock) and preprocessed (Cusha) approaches, by testing four classical algorithms (BFS, PageRank, SSSP and CC). On all the tested applications and

  15. A siphonotid millipede (Rhinotus) as the source of spiropyrrolizidine oximes of dendrobatid frogs.

    Science.gov (United States)

    Saporito, R A; Donnelly, M A; Hoffman, R L; Garraffo, H M; Daly, J W

    2003-12-01

    Poison frogs of the neotropical family Dendrobatidae contain a wide variety of lipophilic alkaloids, which are accumulated from alkaloid-containing arthropods. A small millipede, Rhinotus purpureus (Siphonotidae), occurs microsympatrically with the dendrobatid frog Dendrobates pumilio on Isla Bastimentos, Bocas del Toro Province, Panamá. Methanol extracts of this millipede contain the spiropyrrolizidine O-methyloxime 236, an alkaloid previously known only from skin extracts of poison frogs, including populations of D. pumilio. Thus, R. purpureus represents a likely dietary source of such alkaloids in dendrobatid frogs.

  16. Eugenol Anesthesia in African Clawed Frogs (Xenopus laevis) of Different Body Weights

    OpenAIRE

    Goulet, Félix; Hélie, Pierre; Vachon, Pascal

    2010-01-01

    The objective of this prospective study was to determine the duration of anesthesia in Xenopus laevis frogs of different body weights relative to exposure time in a eugenol (350 µL/L) bath. Two groups of 5 female frogs each weighing 7.5 ± 2.1 g (small frogs) or 29.2 ± 7.4 g (medium frogs) were used. The acetic acid test (AAT), withdrawal reflex, righting reflex, heart rate, and blood oxygen saturation were used to evaluate CNS depression after eugenol bath administration. No responses to the ...

  17. Abundance of Green Tree Frogs and Insects in Artificial Canopy Gaps in a Bottomland Hardwood Forest.

    Energy Technology Data Exchange (ETDEWEB)

    Horn, Scott; Hanula, James, L.; Ulyshen, Michael D.; Kilgo, John, C.

    2005-04-01

    ABSTRACT - We found more green tree frogs ( Hyla cinerea) n canopv gaps than in closed canopy forest. Of the 331 green tree frogs observed, 88% were in canopv gaps. Likewise, higher numbers and biomasses of insects were captured in the open gap habitat Flies were the most commonlv collected insect group accounting for 54% of the total capture. These data suggest that one reason green tree frogs were more abundant in canopy gaps was the increased availability of prey and that small canopy gaps provide early successional habitats that are beneficial to green tree frog populations.

  18. Hypoxic environments as refuge against predatory fish in the Amazonian floodplains

    Directory of Open Access Journals (Sweden)

    MB. Anjos

    Full Text Available Several groups of Amazonian fishes exhibit behavioral, morphological and physiological characteristics that allow occupying hypoxic environments, despite the energetic costs of living in such harsh conditions. One of the supposed advantages of occupying hypoxic habitats would be a lower predation pressure resulting from a lower number of piscivorous fishes in those environments. We tested this hypothesis in an area of the Amazon River floodplain through gill net fishing in normoxic and hypoxic habitats. From the 103 species caught, 38 were classified as piscivores. We found no difference in the number of piscivorous species captured in hypoxic and normoxic habitats (chi2 = 0.23; p = 0.63; df = 1 but piscivorous individuals were more numerous in normoxic than in hypoxic sampling stations (chi2 = 104.4; p < 0.001; df = 1. This indicates that environments submitted to low oxygen conditions may in fact function as refuges against piscivorous fishes in the Amazonian floodplains.

  19. Phenolic constituents and antioxidant activity of geopropolis from two species of amazonian stingless bees

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Ellen Cristina Costa da; Muniz, Magno Perea; Nunomura, Rita de Cassia Saraiva, E-mail: ellensilva@yahoo.com.br [Departamento de Quimica, Instituto de Ciencias Exatas, Universidade Federal do Amazonas, Manaus, AM (Brazil); Nunomura, Sergio Massayoshi [Departamento de Produtos Naturais, Instituto Nacional de Pesquisas da Amazonia, Manaus, AM (Brazil); Zilse, Gislene Almeida Carvalho [Departamento de Biodiversidade, Instituto Nacional de Pesquisas da Amazonia, Manaus, AM (Brazil)

    2013-09-01

    We investigated the phenolic constituents and antioxidant activity of geopropolis from two species of stingless Amazonian bees, Melipona interrupta and Melipona seminigra. The chemical investigation of geopropolis from Melipona interrupta led to the isolation of 5,7,4'-trihydroxyflavonone, 3,5,6,7,4'-pentahydroxyflavonol, naringenine-4'-O-{beta}-D-glucopyranoside and myricetin-3-O-{beta}-D-glucopyranoside. Their structures were assigned based on spectroscopic analyses, including two-dimensional NMR techniques. Antioxidant activity of methanol and ethanol extracts of M. interrupta and M. seminigra were measured using the 1,2-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging assay. This is also the first work reporting the chemical investigation of stingless bee species from the Amazonian region. (author)

  20. Biodiversity, threats and conservation challenges in the Cerrado of Amapá, an Amazonian savanna

    Directory of Open Access Journals (Sweden)

    Karen Mustin

    2017-10-01

    Full Text Available An Amazonian savanna in northern Brazil known as the Cerrado of Amapá is under imminent threat from poor land-use planning, the expansion of large-scale agriculture and other anthropogenic pressures. These savannas house a rich and unique flora and fauna, including endemic plants and animals. However, the area remains under-sampled for most taxa, and better sampling may uncover new species. We estimate that only ~9.16% of these habitats have any kind of protection, and legislative changes threaten to further weaken or remove this protection. Here we present the status of knowledge concerning the biodiversity of the Cerrado of Amapá, its conservation status, and the main threats to the conservation of this Amazonian savanna. To secure the future of these unique and imperilled habitats, we suggest urgent expansion of protected areas, as well as measures that would promote less-damaging land uses to support the local population.

  1. Missing in Amazonian jungle: a case report of skeletal evidence for dismemberment.

    Science.gov (United States)

    Delabarde, Tania; Ludes, Bertrand

    2010-07-01

    This case study presents the results of the recovery and analysis of three sets of disarticulated and incomplete human remains found in Ecuador, within the Amazonian jungle. Recovered body parts sustained extensive sharp force trauma situated on different aspect of the skeleton. The anthropological examination (bone reassembly, biological profile) was followed by a detailed analysis of cut marks, including a basic experimental study on pig bones to demonstrate that dismemberment may have occurred within a certain amount of time after death. Despite the location (deep into the Amazonian jungle) and the perpetrator's actions (dismemberment and dispersion of body parts in a river), forensic work both on the field and in laboratory allowed identification of the victims and the reconstruction of the sequence of events.

  2. Circadian rhythms constrain leaf and canopy gas exchange in an Amazonian forest

    OpenAIRE

    Doughty, Christopher E.; Goulden, Michael L.; Miller, Scott D.; da Rocha, Humberto R.

    2006-01-01

    We used a controlled-environment leaf gas-exchange system and the micrometeorological technique eddy covariance to determine whether circadian rhythms constrain the rates of leaf and canopy gas exchange in an Amazonian forest over a day. When exposed to continuous and constant light for 20 to 48 hours leaves of eleven of seventeen species reduced their photosynthetic rates and closed their stomata during the normally dark period and resumed active gas exchange during the normally light period...

  3. Chromosome number and karyotype of the endangered Amazonian woody Centrolobium paraense Tul. species

    OpenAIRE

    Nair Dahmer; Maria Teresa Schifino Wittmann; Paulo Emilio Kaminski

    2009-01-01

    Centrolobium paraense Tul., popularly known in Brazil as “pau-rainha”, is a species with a high timberpotential, presently endangered due to deforestation of the Amazonian region and indiscriminate wood extraction. Chromosomenumber and karyotype morphology of this species are presented for the first time. All the individuals of the three populationsanalyzed are diploid, with 2n=2x=20 chromosomes. The chromosomes ranging from ca. 1.7 to 4 μm in size. The karyotypeis composed of three metacentr...

  4. An integrative taxonomy approach unveils unknown and threatened moth species in Amazonian rainforest fragments

    Czech Academy of Sciences Publication Activity Database

    Lamarre, Greg P. A.; Decaëns, T.; Rougerie, R.; Barbut, J.; Dewaard, J. R.; Hebert, P. D. N.; Herbin, D.; Laguerre, M.; Thiaucourt, P.; Martins, M. B.

    2016-01-01

    Roč. 9, č. 5 (2016), s. 475-479 ISSN 1752-458X EU Projects: European Commission(XE) 669609 - Diversity6continents Institutional support: RVO:60077344 Keywords : Amazonian forest * Belém center of endemism * centinelan extinction Subject RIV: EG - Zoology Impact factor: 1.840, year: 2016 http://onlinelibrary.wiley.com/doi/10.1111/icad.12187/full

  5. Old World frog and bird vocalizations contain prominent ultrasonic harmonics

    Science.gov (United States)

    Narins, Peter M.; Feng, Albert S.; Lin, Wenyu; Schnitzler, Hans-Ulrich; Denzinger, Annette; Suthers, Roderick A.; Xu, Chunhe

    2004-02-01

    Several groups of mammals such as bats, dolphins and whales are known to produce ultrasonic signals which are used for navigation and hunting by means of echolocation, as well as for communication. In contrast, frogs and birds produce sounds during night- and day-time hours that are audible to humans; their sounds are so pervasive that together with those of insects, they are considered the primary sounds of nature. Here we show that an Old World frog (Amolops tormotus) and an oscine songbird (Abroscopus albogularis) living near noisy streams reliably produce acoustic signals that contain prominent ultrasonic harmonics. Our findings provide the first evidence that anurans and passerines are capable of generating tonal ultrasonic call components and should stimulate the quest for additional ultrasonic species.

  6. Contractile reaction of isolated frog aorta after X-irradiation

    International Nuclear Information System (INIS)

    Michailov, M.C.; Prechter, I.; Greimel, H.; Welscher, U.E.

    1983-01-01

    The action of X-rays (50 kV, filtered by 0.3 mm Al) on helical strip of frog aorta (rana esculenta) has been investigated. The isolated preparations have a stable basal tone and are radio-sensitive to X-rays which induce reversible, dose-dependent, contractile responses. After repeated irradiational tachyphylaxis appears. The threshold doses are about 250 R at 3 to 6 kR/min, antiadrenergic (phentolamine, propranolol), anticholinergic (atropin), antihistaminic (Neo-Bridal) and serotoninergic (Deseril) drugs have no visible influence on the X-ray induced reaction, i.e. these action mechanisms of the irradiation-induced contraction do not seem probable. Theophylline and cAMP inhibit the X-ray contraction probably non-specifically. Indometacin also inhibits the X-ray contraction: this suggests participation of prostaglandin-mechanism on the contraction of frog aorta after irradiation. (orig.) [de

  7. Effect of cattle exclosures on Columbia Spotted Frog abundance

    Science.gov (United States)

    Adams, Michael J.; Pearl, Christopher; Chambert, Thierry; Mccreary, Brome; Galvan, Stephanie; Rowe, Jennifer

    2018-01-01

    Livestock grazing is an important land use in the western USA and can have positive or negative effects on amphibians. Columbia Spotted Frog (Rana luteiventris) often use ponds that provide water for cattle. We conducted a long-term manipulative study on US Forest Service land in northeastern Oregon to determine the effects of full and partial exclosures that limited cattle access to ponds used by frogs. We found weak evidence of a short-term increase in abundance that did not differ between full and partial exclosures and that diminished with continuing exclusion of cattle. The benefit of exclosures was small relative to the overall decline in breeding numbers that we documented. This suggests that some protection can provide a short-term boost to populations.

  8. The rediscovered Hula painted frog is a living fossil.

    Science.gov (United States)

    Biton, Rebecca; Geffen, Eli; Vences, Miguel; Cohen, Orly; Bailon, Salvador; Rabinovich, Rivka; Malka, Yoram; Oron, Talya; Boistel, Renaud; Brumfeld, Vlad; Gafny, Sarig

    2013-01-01

    Amphibian declines are seen as an indicator of the onset of a sixth mass extinction of life on earth. Because of a combination of factors such as habitat destruction, emerging pathogens and pollutants, over 156 amphibian species have not been seen for several decades, and 34 of these were listed as extinct by 2004. Here we report the rediscovery of the Hula painted frog, the first amphibian to have been declared extinct. We provide evidence that not only has this species survived undetected in its type locality for almost 60 years but also that it is a surviving member of an otherwise extinct genus of alytid frogs, Latonia, known only as fossils from Oligocene to Pleistocene in Europe. The survival of this living fossil is a striking example of resilience to severe habitat degradation during the past century by an amphibian.

  9. The Genome of the Western Clawed Frog Xenopus tropicalis

    Energy Technology Data Exchange (ETDEWEB)

    Hellsten, Uffe; Harland, Richard M.; Gilchrist, Michael J.; Hendrix, David; Jurka, Jerzy; Kapitonov, Vladimir; Ovcharenko, Ivan; Putnam, Nicholas H.; Shu, Shengqiang; Taher, Leila; Blitz, Ira L.; Blumberg, Bruce; Dichmann, Darwin S.; Dubchak, Inna; Amaya, Enrique; Detter, John C.; Fletcher, Russell; Gerhard, Daniela S.; Goodstein, David; Graves, Tina; Grigoriev, Igor V.; Grimwood, Jane; Kawashima, Takeshi; Lindquist, Erika; Lucas, Susan M.; Mead, Paul E.; Mitros, Therese; Ogino, Hajime; Ohta, Yuko; Poliakov, Alexander V.; Pollet, Nicolas; Robert, Jacques; Salamov, Asaf; Sater, Amy K.; Schmutz, Jeremy; Terry, Astrid; Vize, Peter D.; Warren, Wesley C.; Wells, Dan; Wills, Andrea; Wilson, Richard K.; Zimmerman, Lyle B.; Zorn, Aaron M.; Grainger, Robert; Grammer, Timothy; Khokha, Mustafa K.; Richardson, Paul M.; Rokhsar, Daniel S.

    2009-10-01

    The western clawed frog Xenopus tropicalis is an important model for vertebrate development that combines experimental advantages of the African clawed frog Xenopus laevis with more tractable genetics. Here we present a draft genome sequence assembly of X. tropicalis. This genome encodes over 20,000 protein-coding genes, including orthologs of at least 1,700 human disease genes. Over a million expressed sequence tags validated the annotation. More than one-third of the genome consists of transposable elements, with unusually prevalent DNA transposons. Like other tetrapods, the genome contains gene deserts enriched for conserved non-coding elements. The genome exhibits remarkable shared synteny with human and chicken over major parts of large chromosomes, broken by lineage-specific chromosome fusions and fissions, mainly in the mammalian lineage.

  10. The genome of the Western clawed frog Xenopus tropicalis.

    Science.gov (United States)

    Hellsten, Uffe; Harland, Richard M; Gilchrist, Michael J; Hendrix, David; Jurka, Jerzy; Kapitonov, Vladimir; Ovcharenko, Ivan; Putnam, Nicholas H; Shu, Shengqiang; Taher, Leila; Blitz, Ira L; Blumberg, Bruce; Dichmann, Darwin S; Dubchak, Inna; Amaya, Enrique; Detter, John C; Fletcher, Russell; Gerhard, Daniela S; Goodstein, David; Graves, Tina; Grigoriev, Igor V; Grimwood, Jane; Kawashima, Takeshi; Lindquist, Erika; Lucas, Susan M; Mead, Paul E; Mitros, Therese; Ogino, Hajime; Ohta, Yuko; Poliakov, Alexander V; Pollet, Nicolas; Robert, Jacques; Salamov, Asaf; Sater, Amy K; Schmutz, Jeremy; Terry, Astrid; Vize, Peter D; Warren, Wesley C; Wells, Dan; Wills, Andrea; Wilson, Richard K; Zimmerman, Lyle B; Zorn, Aaron M; Grainger, Robert; Grammer, Timothy; Khokha, Mustafa K; Richardson, Paul M; Rokhsar, Daniel S

    2010-04-30

    The western clawed frog Xenopus tropicalis is an important model for vertebrate development that combines experimental advantages of the African clawed frog Xenopus laevis with more tractable genetics. Here we present a draft genome sequence assembly of X. tropicalis. This genome encodes more than 20,000 protein-coding genes, including orthologs of at least 1700 human disease genes. Over 1 million expressed sequence tags validated the annotation. More than one-third of the genome consists of transposable elements, with unusually prevalent DNA transposons. Like that of other tetrapods, the genome of X. tropicalis contains gene deserts enriched for conserved noncoding elements. The genome exhibits substantial shared synteny with human and chicken over major parts of large chromosomes, broken by lineage-specific chromosome fusions and fissions, mainly in the mammalian lineage.

  11. Phylogenetic insights into the diversity of homocytous cyanobacteria from Amazonian rivers.

    Science.gov (United States)

    Genuário, Diego Bonaldo; Vaz, Marcelo Gomes Marçal Vieira; Melo, Itamar Soares de

    2017-11-01

    The Amazon Rainforest holds great tropical biodiversity, mainly because of its favourable climatic conditions. The high temperatures, luminosity and humidity coupled with the nutritional simplicity of cyanobacteria allow undiscovered diversity to flourish within this group of microorganisms. Some efforts to reveal this diversity have been attempted; however, most were focused on the microscopic observation of environmental samples without any genetic information. Very few studies focusing on morphological, ecological and molecular criteria have been conducted, and none have been devoted to homocytous cyanobacteria forms in Amazonia region. Therefore, the genetic relationships amongst strains retrieved from this ecosystem with regard to other environments from Brazil and the world have not been tested and, consequently, the Amazonian strains would naturally be assumed as novel to science. To examine these relationships, cultured homocytous cyanobacteria isolated from two Amazonian rivers (Amazonas and Solimões) were evaluated using a phylogenetic perspective, considering the 16S rRNA gene sequence. A total of eleven homocytous cyanobacterial strains were isolated. Morphologically, they were identified as Pseudanabaena, Leptolyngbya, Planktothrix and Phormidium, but genetically they were included in the typical clusters of Planktothrix, Pseudanabaena, Cephalothrix, Pantanalinema and Alkalinema. These three latter genera have been detected in other Brazilian ecosystems only (Pantanal, Atlantic Rainforest and Pampa), while those remaining have been extensively found in many parts of the world. The data provided here indicate that Amazonian rivers support a homocytous cyanobacterial diversity previously reported from other geographical and ecological environments. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Hydrological pulse regulating the bacterial heterotrophic metabolism between Amazonian mainstems and floodplain lakes

    Science.gov (United States)

    Vidal, Luciana O.; Abril, Gwenäel; Artigas, Luiz F.; Melo, Michaela L.; Bernardes, Marcelo C.; Lobão, Lúcia M.; Reis, Mariana C.; Moreira-Turcq, Patrícia; Benedetti, Marc; Tornisielo, Valdemar L.; Roland, Fabio

    2015-01-01

    We evaluated in situ rates of bacterial carbon processing in Amazonian floodplain lakes and mainstems, during both high water (HW) and low water (LW) phases (p < 0.05). Our results showed that bacterial production (BP) was lower and more variable than bacterial respiration, determined as total respiration. Bacterial carbon demand was mostly accounted by BR and presented the same pattern that BR in both water phases. Bacterial growth efficiency (BGE) showed a wide range (0.2–23%) and low mean value of 3 and 6%, (in HW and LW, respectively) suggesting that dissolved organic carbon was mostly allocated to catabolic metabolism. However, BGE was regulated by BP in LW phase. Consequently, changes in BGE showed the same pattern that BP. In addition, the hydrological pulse effects on mainstems and floodplains lakes connectivity were found for BP and BGE in LW. Multiple correlation analyses revealed that indexes of organic matter (OM) quality (chlorophyll-a, N stable isotopes and C/N ratios) were the strongest seasonal drivers of bacterial carbon metabolism. Our work indicated that: (i) the bacterial metabolism was mostly driven by respiration in Amazonian aquatic ecosystems resulting in low BGE in either high or LW phase; (ii) the hydrological pulse regulated the bacterial heterotrophic metabolism between Amazonian mainstems and floodplain lakes mostly driven by OM quality. PMID:26483776

  13. Geology and insolation-driven climatic history of Amazonian north polar materials on Mars.

    Science.gov (United States)

    Tanaka, Kenneth L

    2005-10-13

    Mariner 9 and Viking spacecraft images revealed that the polar regions of Mars, like those of Earth, record the planet's climate history. However, fundamental uncertainties regarding the materials, features, ages and processes constituting the geologic record remained. Recently acquired Mars Orbiter Laser Altimeter data and Mars Orbiter Camera high-resolution images from the Mars Global Surveyor spacecraft and moderately high-resolution Thermal Emission Imaging System visible images from the Mars Odyssey spacecraft permit more comprehensive geologic and climatic analyses. Here I map and show the history of geologic materials and features in the north polar region that span the Amazonian period (approximately 3.0 Gyr ago to present). Erosion and redeposition of putative circumpolar mud volcano deposits (formed by eruption of liquefied, fine-grained material) led to the formation of an Early Amazonian polar plateau consisting of dark layered materials. Crater ejecta superposed on pedestals indicate that a thin mantle was present during most of the Amazonian, suggesting generally higher obliquity and insolation conditions at the poles than at present. Brighter polar layered deposits rest unconformably on the dark layers and formed mainly during lower obliquity over the past 4-5 Myr (ref. 20). Finally, the uppermost layers post-date the latest downtrend in obliquity <20,000 years ago.

  14. Geology and insolation-driven climatic history of Amazonian north polar materials on Mars

    Science.gov (United States)

    Tanaka, K.L.

    2005-01-01

    Mariner 9 and Viking spacecraft images revealed that the polar regions of Mars, like those of Earth, record the planet's climate history. However, fundamental uncertainties regarding the materials, features, ages and processes constituting the geologic record remained. Recently acquired Mars Orbiter Laser Altimeter data and Mars Orbiter Camera high-resolution images from the Mars Global Surveyor spacecraft and moderately high-resolution Thermal Emission Imaging System visible images from the Mars Odyssey spacecraft permit more comprehensive geologic and climatic analyses. Here I map and show the history of geologic materials and features in the north polar region that span the Amazonian period (???3.0 Gyr ago to present). Erosion and redeposition of putative circumpolar mud volcano deposits (formed by eruption of liquefied, fine-grained material) led to the formation of an Early Amazonian polar plateau consisting of dark layered materials. Crater ejecta superposed on pedestals indicate that a thin mantle was present during most of the Amazonian, suggesting generally higher obliquity and insolation conditions at the poles than at present. Brighter polar layered deposits rest unconformably on the dark layers and formed mainly during lower obliquity over the past 4-5 Myr (ref. 20). Finally, the uppermost layers post-date the latest downtrend in obliquity <20,000 years ago. ?? 2005 Nature Publishing Group.

  15. Estimating the global conservation status of more than 15,000 Amazonian tree species

    Science.gov (United States)

    ter Steege, Hans; Pitman, Nigel C. A.; Killeen, Timothy J.; Laurance, William F.; Peres, Carlos A.; Guevara, Juan Ernesto; Salomão, Rafael P.; Castilho, Carolina V.; Amaral, Iêda Leão; de Almeida Matos, Francisca Dionízia; de Souza Coelho, Luiz; Magnusson, William E.; Phillips, Oliver L.; de Andrade Lima Filho, Diogenes; de Jesus Veiga Carim, Marcelo; Irume, Mariana Victória; Martins, Maria Pires; Molino, Jean-François; Sabatier, Daniel; Wittmann, Florian; López, Dairon Cárdenas; da Silva Guimarães, José Renan; Mendoza, Abel Monteagudo; Vargas, Percy Núñez; Manzatto, Angelo Gilberto; Reis, Neidiane Farias Costa; Terborgh, John; Casula, Katia Regina; Montero, Juan Carlos; Feldpausch, Ted R.; Honorio Coronado, Euridice N.; Montoya, Alvaro Javier Duque; Zartman, Charles Eugene; Mostacedo, Bonifacio; Vasquez, Rodolfo; Assis, Rafael L.; Medeiros, Marcelo Brilhante; Simon, Marcelo Fragomeni; Andrade, Ana; Camargo, José Luís; Laurance, Susan G. W.; Nascimento, Henrique Eduardo Mendonça; Marimon, Beatriz S.; Marimon, Ben-Hur; Costa, Flávia; Targhetta, Natalia; Vieira, Ima Célia Guimarães; Brienen, Roel; Castellanos, Hernán; Duivenvoorden, Joost F.; Mogollón, Hugo F.; Piedade, Maria Teresa Fernandez; Aymard C., Gerardo A.; Comiskey, James A.; Damasco, Gabriel; Dávila, Nállarett; García-Villacorta, Roosevelt; Diaz, Pablo Roberto Stevenson; Vincentini, Alberto; Emilio, Thaise; Levis, Carolina; Schietti, Juliana; Souza, Priscila; Alonso, Alfonso; Dallmeier, Francisco; Ferreira, Leandro Valle; Neill, David; Araujo-Murakami, Alejandro; Arroyo, Luzmila; Carvalho, Fernanda Antunes; Souza, Fernanda Coelho; do Amaral, Dário Dantas; Gribel, Rogerio; Luize, Bruno Garcia; Pansonato, Marcelo Petrati; Venticinque, Eduardo; Fine, Paul; Toledo, Marisol; Baraloto, Chris; Cerón, Carlos; Engel, Julien; Henkel, Terry W.; Jimenez, Eliana M.; Maas, Paul; Mora, Maria Cristina Peñuela; Petronelli, Pascal; Revilla, Juan David Cardenas; Silveira, Marcos; Stropp, Juliana; Thomas-Caesar, Raquel; Baker, Tim R.; Daly, Doug; Paredes, Marcos Ríos; da Silva, Naara Ferreira; Fuentes, Alfredo; Jørgensen, Peter Møller; Schöngart, Jochen; Silman, Miles R.; Arboleda, Nicolás Castaño; Cintra, Bruno Barçante Ladvocat; Valverde, Fernando Cornejo; Di Fiore, Anthony; Phillips, Juan Fernando; van Andel, Tinde R.; von Hildebrand, Patricio; Barbosa, Edelcilio Marques; de Matos Bonates, Luiz Carlos; de Castro, Deborah; de Sousa Farias, Emanuelle; Gonzales, Therany; Guillaumet, Jean-Louis; Hoffman, Bruce; Malhi, Yadvinder; de Andrade Miranda, Ires Paula; Prieto, Adriana; Rudas, Agustín; Ruschell, Ademir R.; Silva, Natalino; Vela, César I. A.; Vos, Vincent A.; Zent, Eglée L.; Zent, Stanford; Cano, Angela; Nascimento, Marcelo Trindade; Oliveira, Alexandre A.; Ramirez-Angulo, Hirma; Ramos, José Ferreira; Sierra, Rodrigo; Tirado, Milton; Medina, Maria Natalia Umaña; van der Heijden, Geertje; Torre, Emilio Vilanova; Vriesendorp, Corine; Wang, Ophelia; Young, Kenneth R.; Baider, Claudia; Balslev, Henrik; de Castro, Natalia; Farfan-Rios, William; Ferreira, Cid; Mendoza, Casimiro; Mesones, Italo; Torres-Lezama, Armando; Giraldo, Ligia Estela Urrego; Villarroel, Daniel; Zagt, Roderick; Alexiades, Miguel N.; Garcia-Cabrera, Karina; Hernandez, Lionel; Huamantupa-Chuquimaco, Isau; Milliken, William; Cuenca, Walter Palacios; Pansini, Susamar; Pauletto, Daniela; Arevalo, Freddy Ramirez; Sampaio, Adeilza Felipe; Valderrama Sandoval, Elvis H.; Gamarra, Luis Valenzuela

    2015-01-01

    Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict that most of the world’s >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century. PMID:26702442

  16. Extremely long-distance seed dispersal by an overfished Amazonian frugivore.

    Science.gov (United States)

    Anderson, Jill T; Nuttle, Tim; Saldaña Rojas, Joe S; Pendergast, Thomas H; Flecker, Alexander S

    2011-11-22

    Throughout Amazonia, overfishing has decimated populations of fruit-eating fishes, especially the large-bodied characid, Colossoma macropomum. During lengthy annual floods, frugivorous fishes enter vast Amazonian floodplains, consume massive quantities of fallen fruits and egest viable seeds. Many tree and liana species are clearly specialized for icthyochory, and seed dispersal by fish may be crucial for the maintenance of Amazonian wetland forests. Unlike frugivorous mammals and birds, little is known about seed dispersal effectiveness of fishes. Extensive mobility of frugivorous fish could result in extremely effective, multi-directional, long-distance seed dispersal. Over three annual flood seasons, we tracked fine-scale movement patterns and habitat use of wild Colossoma, and seed retention in the digestive tracts of captive individuals. Our mechanistic model predicts that Colossoma disperses seeds extremely long distances to favourable habitats. Modelled mean dispersal distances of 337-552 m and maximum of 5495 m are among the longest ever reported. At least 5 per cent of seeds are predicted to disperse 1700-2110 m, farther than dispersal by almost all other frugivores reported in the literature. Additionally, seed dispersal distances increased with fish size, but overfishing has biased Colossoma populations to smaller individuals. Thus, overexploitation probably disrupts an ancient coevolutionary relationship between Colossoma and Amazonian plants.

  17. Electrophysiological evidence for an ATP-gated ion channel in the principal cells of the frog skin epithelium

    DEFF Research Database (Denmark)

    Brodin, Birger; Nielsen, Robert

    2000-01-01

    P2X receptor, Na+ absorption, Short circuit current, Cell potential, Microelectrodes, Frog skin, Cytosolic Ca2+......P2X receptor, Na+ absorption, Short circuit current, Cell potential, Microelectrodes, Frog skin, Cytosolic Ca2+...

  18. Correlation between chloride flux via the mitochondria-rich cells and transepithelial water movement in isolated frog skin (Rana esculenta)

    DEFF Research Database (Denmark)

    Nielsen, Robert

    1995-01-01

    Antidiuretic hormone; chloride transport; electroosmosis; Frog skin; Intercalated cells; Local osmosis; Mitochondria-rich cells.......Antidiuretic hormone; chloride transport; electroosmosis; Frog skin; Intercalated cells; Local osmosis; Mitochondria-rich cells....

  19. Scheloribatid mites as the source of pumiliotoxins in dendrobatid frogs.

    Science.gov (United States)

    Takada, Wataru; Sakata, Tomoyo; Shimano, Satoshi; Enami, Yoshinari; Mori, Naoki; Nishida, Ritsuo; Kuwahara, Yasumasa

    2005-10-01

    The strawberry poison frog Dendrobates pumilio (Anura: Dendrobatidae) and related poison frogs contain a variety of dendrobatid alkaloids that are considered to be sequestered through the consumption of alkaloid-containing arthropods microsympatrically distributed in the habitat. In addition to ants, beetles, and millipedes, we found that adults of two species of oribatid mites belonging to the cohort Brachypylina, trophically a lower level of animal than ants and beetles, contain dendrobatid alkaloids. Gas chromatography/mass spectrometry (GC/MS) of hexane extracts of adult Scheloribates azumaensis (Oribatida: Acari) revealed the presence of not only pumiliotoxin 251D (8-hydroxy-8-methyl-6-(2'-methylhexylidene)-1-azabicyclo[4.3.0]nonane), but also precoccinelline 193C and another coccinelline-type alkaloid. From the corresponding extracts of an unidentified Scheloribates sp., pumiliotoxin 237A (8-hydroxy-8-methyl-6-(2'-methylpentylidene)-1-azabicyclo[4.3.0]nonane) was detected as a minor component, and identified by synthesis. The presence of related alkaloids, namely deoxypumiliotoxin 193H, a 6,8-diethyl-5-propenylindolizidine, and tentatively, a 1-ethyl-4-pentenynylquinolizidine, were indicated by the GC/MS fragmentation patterns, along with at least another six unidentified alkaloid components. Thus, one possible origin of pumiliotoxins, coccinellid alkaloids, and certain izidines found in poison frogs may be mites of the genus Scheloribates and perhaps related genera in the suborder Oribatida.

  20. The role of predator selection on polymorphic aposematic poison frogs.

    Science.gov (United States)

    Noonan, Brice P; Comeault, Aaron A

    2009-02-23

    Demonstrations of interactions between diverse selective forces on bright coloration in defended species are rare. Recent work has suggested that not only do the bright colours of Neotropical poison frogs serve to deter predators, but they also play a role in sexual selection, with females preferring males similar to themselves. These studies report an interaction between the selective forces of mate choice and predation. However, evidence demonstrating phenotypic discrimination by potential predators on these polymorphic species is lacking. The possibility remains that visual (avian) predators possess an inherent avoidance of brightly coloured diurnal anurans and purifying selection against novel phenotypes within populations is due solely to non-random mating. Here, we examine the influence of predation on phenotypic variation in a polymorphic species of poison frog, Dendrobates tinctorius. Using clay models, we demonstrate a purifying role for predator selection, as brightly coloured novel forms are more likely to suffer an attack than both local aposematic and cryptic forms. Additionally, local aposematic forms are attacked, though infrequently, indicating ongoing testing/learning and a lack of innate avoidance. These results demonstrate predator-driven phenotypic purification within populations and suggest colour patterns of poison frogs may truly represent a 'magic trait'.

  1. Radioimmunoassay for plasma corticotropin in frogs (Rana esculenta L.)

    International Nuclear Information System (INIS)

    Vaudry, H.; Vague, P.; Dupont, W.; Leboulenger, F.; Vaillant, R.

    1975-01-01

    A radioimmunoassay technique has been developed for measuring frog plasma corticotropin (ACTH) without prior extraction. Using synthetic porcine ACTH as a reference standard, 131 I-labeled synthetic human ACTH (sp act greater than 500 mCi/mg) as tracer and rabbit anti-porcine ACTH serum, the lower measurable value was estimated at about 4 pg ACTH. Only human and porcine ACTH, ACTH, and frog pituitary ACTH reacted with the rabbit anti-porcine ACTH serum. No cross-reactivity has been found with synthetic ACTH, αMSH, and bovine βMSH. Appearance of damaged 131 I-h ACTH components after storage in plasma solutions was followed for 7 days. The conditions making it possible to reduce ACTH damage have been ascertained. The average plasma corticotropin level (+- CI) was found to be 38.8 +- 7.8 pg/ml without any significant difference between males and females. These results suggest that frog ACTH secretion has much in common with mammalian secretions

  2. Effects of the herbicide imazapyr on juvenile Oregon spotted frogs

    Science.gov (United States)

    Yahnke, Amy E.; Grue, Christian E.; Hayes, Marc P.; Troiano, Alexandra T.

    2013-01-01

    Conflict between native amphibians and aquatic weed management in the Pacific Northwest is rarely recognized because most native stillwater-breeding amphibian species move upland during summer, when herbicide application to control weeds in aquatic habitats typically occurs. However, aquatic weed management may pose a risk for aquatic species present in wetlands through the summer, such as the Oregon spotted frog (OSF, Rana pretiosa), a state endangered species in Washington. Acute toxicity of herbicides used to control aquatic weeds tends to be low, but the direct effects of herbicide tank mixes on OSFs have remained unexamined. We exposed juvenile OSFs to tank mixes of the herbicide imazapyr, a surfactant, and a marker dye in a 96-h static-renewal test. The tank mix was chosen because of its low toxicity to fish and its effectiveness in aquatic weed control. Concentrations were those associated with low-volume (3.5 L/ha) and high-volume (7.0 L/ha) applications of imazapyr and a clean-water control. Following exposure, frogs were reared for two months in clean water to identify potential latent effects on growth. Endpoints evaluated included feeding behavior, growth, and body and liver condition indices. We recorded no mortalities and found no significant differences for any end point between the herbicide-exposed and clean-water control frogs. The results suggest that imazapyr use in wetland restoration poses a low risk of direct toxic effects on juvenile OSFs.

  3. Internal pigment cells respond to external UV radiation in frogs.

    Science.gov (United States)

    Franco-Belussi, Lilian; Nilsson Sköld, Helen; de Oliveira, Classius

    2016-05-01

    Fish and amphibians have pigment cells that generate colorful skins important for signaling, camouflage, thermoregulation and protection against ultraviolet radiation (UVR). However, many animals also have pigment cells inside their bodies, on their internal organs and membranes. In contrast to external pigmentation, internal pigmentation is remarkably little studied and its function is not well known. Here, we tested genotoxic effects of UVR and its effects on internal pigmentation in a neotropical frog, Physalaemus nattereri We found increases in body darkness and internal melanin pigmentation in testes and heart surfaces and in the mesenterium and lumbar region after just a few hours of UVR exposure. The melanin dispersion in melanomacrophages in the liver and melanocytes in testes increased after UV exposure. In addition, the amount of melanin inside melanomacrophages cells also increased. Although mast cells were quickly activated by UVR, only longer UVR exposure resulted in genotoxic effects inside frogs, by increasing the frequency of micronuclei in red blood cells. This is the first study to describe systemic responses of external UVR on internal melanin pigmentation, melanomacrophages and melanocytes in frogs and thus provides a functional explanation to the presence of internal pigmentation. © 2016. Published by The Company of Biologists Ltd.

  4. Antimicrobial peptide defenses of the Tarahumara frog, Rana tarahumarae.

    Science.gov (United States)

    Rollins-Smith, Louise A; Reinert, Laura K; Miera, Verma; Conlon, J Michael

    2002-09-20

    Populations of the Tarahumara frog Rana tarahumarae have decreased markedly in recent years in the northern part of their range. Infection by the chytrid fungus Batrachochytrium dendrobatidis has been implicated in these declines. To determine whether antimicrobial peptides in the skin provide protection against this pathogen, norepinephrine-stimulated skin secretions were tested for their ability to inhibit growth of B. dendrobatidis in vitro. After concentration, crude mixtures of skin peptides inhibited the growth of the chytrid in a concentration-dependent manner. Proteomic analysis led to the identification and characterization of three peptides belonging to the brevinin-1 family of antimicrobial peptides and three belonging to the ranatuerin-2 family. The two most abundant peptides, ranatuerin-2TRa (GIMDSIKGAAKEIAGHLLDNLKCKITGC) and brevinin-1TRa (FLPVIAGIAANVLPKLFCKLTKRC), were active against B. dendrobatidis (MIC of 50 microM for ranatuerin-2TRa and 12.5 microM for brevinin-1TRa against zoospores). These data clearly show that antimicrobial peptides in the skin secretions of the Tarahumara frog are active against B. dendrobatidis and should provide some protection against infection. Therefore, the observed susceptibility of these frogs to this pathogen in the wild may be due to the effects of additional environmental factors that impair this innate defense mechanism, leading to the observed population declines.

  5. Polyandry, Predation, and the Evolution of Frog Reproductive Modes.

    Science.gov (United States)

    Zamudio, Kelly R; Bell, Rayna C; Nali, Renato C; Haddad, Célio F B; Prado, Cynthia P A

    2016-09-01

    Frog reproductive modes are complex phenotypes that include egg/clutch characteristics, oviposition site, larval development, and sometimes, parental care. Two evident patterns in the evolution of these traits are the higher diversity of reproductive modes in the tropics and the apparent progression from aquatic to terrestrial reproduction, often attributed to higher fitness resulting from decreased predation on terrestrial eggs and tadpoles. Here, we propose that sexual selection-and not only natural selection due to predation-favors terrestrial breeding by reducing the loss of fitness due to polyandry. To examine this novel selective mechanism, we reconstructed the evolution of reproductive diversity in two frog families (Hylidae and Leptodactylidae) and tested for concerted evolution of egg and tadpole development sites with specific mating behaviors. We found that oviposition and tadpole development sites are evolving independently, do not show the same diversity and/or directionality in terms of terrestriality, and thus may be diversifying due to different selective mechanisms. In both families, terrestrial egg deposition is correlated with amplexus that is hidden from competing males, and in hylids, testes mass was significantly larger and more variable in males with exposed amplexus that are vulnerable to polyandry. Our results indicate that intrasexual selection has been an underappreciated mechanism promoting diversification of frog reproductive modes.

  6. Life history and environment of Cecropia latiloba in Amazonian floodplains

    Directory of Open Access Journals (Sweden)

    Pia Parolin

    2002-06-01

    Full Text Available Cecropia latiloba can be considered to be one of the most efficient colonizers of open areas in the nutrient-rich whitewater floodplains of the Amazon river. Its main strategy to be successful is the high tolerance towards waterlogging and submergence, and the fast vertical growth and reiteration capacity. This, and the tolerance of high irradiation and sediment deposition allow C. latiloba to form large monospecific stands on open sites, and thus the first closed canopy which represents the initial phase of a successional sequence which leads to highly diverse forests. This tree is extremely well adapted to the adverse growth conditions in Amazonian floodplains with prolongued periods of flooding and seedling submergence. The species occurs on the lowest levels in the flooding gradient. Although it belongs to the most often cited species under aspects of taxonomy, species distribution and general descriptions of the ecosystem, little has been published about its ecology. In the present paper the ecological, physiological and phenological characteristics of C. latiloba are described. It is an evergreen species which constantly produces new leaves. With flooding, leaf production is reduced but new leaves are flushed also with prolongued flooding. The peak of flowering and fruiting are in the flooded period. When mature, the fruits are dispersed mainly by water and fish. Seed germination occurs, without dormancy, within 5-13 days after water retreat. In the 7 months before the first flooded period seedlings reach 1 m of height, and height growth increases until a height of 15-20 m is achieved. Photosynthetic assimilation is high, with values of up to 21 mmol CO2m-2s-1 . C. latiloba is a very flood tolerant species, and waterlogged seedlings continuously produce new leaves and adventitiuos rootsCecropia latiloba puede ser considerada una de las especies colonizadoras más eficientes de áreas abiertas en las llanuras inundadas de agua dulce, rica

  7. IgE antibodies of fish allergic patients cross-react with frog parvalbumin.

    Science.gov (United States)

    Hilger, C; Thill, L; Grigioni, F; Lehners, C; Falagiani, P; Ferrara, A; Romano, C; Stevens, W; Hentges, F

    2004-06-01

    The major allergens in fish are parvalbumins. Important immunoglobulin (Ig)E cross-recognition of parvalbumins from different fish species has been shown. Recently frog parvalbumin alpha has been found to be responsible for a case of IgE-mediated anaphylaxis triggered by the ingestion of frog meat. The aim of this study was to investigate whether IgE antibodies of fish allergic persons cross-react with frog parvalbumin and to appreciate its clinical relevance. The sera of 15 fish allergic patients and one fish and frog allergic patient were tested by IgE-immunoblotting against frog muscle extract. Sera were tested against recombinant parvalbumin alpha and beta from Rana esculenta. Skin prick tests were performed in selected patients with recombinant frog parvalbumin. Ca(2+) depletion experiments and inhibition studies with purified cod and frog recombinant parvalbumin were done to characterize the cross-reactive pattern. Fourteen of the sera tested had IgE antibodies recognizing low molecular weight components in frog muscle extract. Calcium depletion experiments or inhibition of patient sera with purified cod parvalbumin led to a significant or complete decrease in IgE binding. When tested against recombinant parvalbumins, three of 13 sera reacted with alpha parvalbumin and 11 of 12 reacted with beta parvalbumin from R. esculenta. Skin prick tests performed with recombinant frog parvalbumin were positive in fish allergic patients. Inhibition studies showed that a fish and frog allergic patient was primarily sensitized to fish parvalbumin. Cod parvalbumin, a major cross-reactive allergen among different fish species, shares IgE binding epitopes with frog parvalbumin. This in vitro cross-reactivity seems to be also clinically relevant. Parvalbumins probably represent a new family of cross-reactive allergens.

  8. Which frog's legs do froggies eat? The use of DNA barcoding for identification of deep frozen frog legs (Dicroglossidae, Amphibia) commercialized in France

    OpenAIRE

    Ohler, Annemarie; Nicolas, Violaine

    2017-01-01

    International audience; Several millions frogs captured in the wild in Indonesia are sold for food yearly in French supermarkets, as deep frozen frog legs. They are commercialized as Rana macrodon, but up to 15 look-alike species might also be concerned by this trade. From December 2012 to May 2013, we bought 209 specimens of deep frozen frog legs, and identified them through a barcoding approach based on the 16S gene. Our results show that 206 out of the 209 specimens belong to Fejervarya ca...

  9. An addition to the diversity of dendrobatid frogs in Venezuela: description of three new collared frogs (Anura: Dendrobatidae: Mannophryne

    Directory of Open Access Journals (Sweden)

    César Luis Barrio-Amorós

    2010-07-01

    Full Text Available Three new species of collared frogs of the genus Mannophryne are described from Venezuela. Two are newly discovered taxa from the Venezuelan Andes, whereas the third species, previously confused with M. trinitatis, is from the Caracas area in the Cordillera de la Costa. The call of the three new species and that of Mannophryne collaris are described. Taxonomic, zoogeographic, and conservation issues are discussed.

  10. 76 FR 45602 - Proposed Safe Harbor Agreement for California Red-Legged Frog, at Swallow Creek Ranch, San Luis...

    Science.gov (United States)

    2011-07-29

    ... Fish and Wildlife Service Proposed Safe Harbor Agreement for California Red-Legged Frog, at Swallow... the Federally threatened California red-legged frog (Rana draytonii), under the Endangered Species Act... California red-legged frog on the property subject to the Agreement (Enrolled Property), which is owned and...

  11. Protamine-like sperm nuclear basic proteins in the primitive frog Ascaphus truei and histone reversions among more advanced frogs.

    Science.gov (United States)

    Kasinsky, H E; Gutovich, L; Kulak, D; Mackay, M; Green, D M; Hunt, J; Ausio, J

    1999-12-01

    Sperm nuclear basic proteins (SNBPs) that condense chromatin are very diverse. In animals, evolution of SNBPs has proceeded from lysine-rich histone H type in sponges to more arginine-rich protamine-like PL and protamine P types. Yet sporadic PL/P to H reversions are known to occur in both protostomes and deuterostomes. To determine why this is the case, we have examined SNBPs in eleven anuran species. We find that sperm of the primitive, internally fertilizing archeobatrachian frog A. truei (family Ascaphidae) has PL/P type (42 mol % arginine), with an electrophoretic profile similar to SNBPs in another archeobatrachian, externally fertilizing Leiopelma hochstetteri (family Leiopelmatidae). Cytochemistry of sperm nuclei in the advanced, externally fertilizing neobatrachian frogs Crinia signifera and C. deserticola (family Myobatrachidae) indicates that they have reverted to H type SNBPs. This is also known to be the case in externally fertilizing Rana (family Ranidae) and Silurana, a subgenus of Xenopus (family Pipidae). Such a trend, from PL/P type SNBPs in two archeobatrachians to sporadic reversions to H type in more advanced frogs, parallels the ultrastructural simplification from complex A. truei introsperm to neobatrachian aquasperm that Jamieson et al. (1993. Herpetologica 49:52-65) attribute as a secondary reversion to external fertilization.

  12. Frog ANP increases the amiloride-sensitive Na(+) channel activity in urinary bladder cells of Japanese tree frog, Hyla japonica.

    Science.gov (United States)

    Yamada, Toshiki; Matsuda, Kouhei; Uchiyama, Minoru

    2007-01-01

    We examined the mechanism of amiloride-sensitive Na(+) channels (ENaC) activated by fANP in epithelial cells of frog urinary bladder by using a cell-attached patch-clamp technique. ENaC activities in the epithelial cells were significantly increased following administration of both 10(-9)M fANP and 10(-5)M 8-Br-cGMP. Both fANP and 8-Br-cGMP, however, failed to activate the ENaC in the presence of 10(-6)M amiloride. In addition, 8-Br-cGMP failed to activate the ENaC in the presence of a PKA inhibitor, KT-5720. In the next experiment, we measured both cGMP and cAMP production levels after treatment of fANP on the frog urinary bladder cells. Frog ANP significantly increased cGMP production, but not the cAMP production. Taken together, these results suggest that fANP activates ENaC through increases in cGMP production and activation of PKA.

  13. Energetic planning in isolated Amazonian communities using geographical information system; Planejamento energetico em regioes isoladas da Amazonia utilizando sistemas de informacoes geograficas

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Arthur [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Programa de Pos-Graduacao de Engenharia Eletrica; Rocha, Brigida R.P.; Monteiro, Jose H.A.; Gaspar, Gabriella C.M. [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Dept. de Engenharia Eletrica e de Computacao; Aarao Junior, Raimundo N.N. [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Dept. de Engenharia Mecanica

    2004-07-01

    This paper proposes a system of electric planning in isolated Amazonian communities. For those communities, we propose the use of decentralized systems of electric energy with biomass as fuel. We also propose a computer system of electric planning with geographical information systems for its facilities of integrating geographical information, so useful in an Amazonian context. (author)

  14. Complex and transitive synchronization in a frustrated system of calling frogs

    Science.gov (United States)

    Aihara, Ikkyu; Takeda, Ryu; Mizumoto, Takeshi; Otsuka, Takuma; Takahashi, Toru; Okuno, Hiroshi G.; Aihara, Kazuyuki

    2011-03-01

    This letter reports synchronization phenomena and mathematical modeling on a frustrated system of living beings, or Japanese tree frogs (Hyla japonica). While an isolated male Japanese tree frog calls nearly periodically, he can hear sounds including calls of other males. Therefore, the spontaneous calling behavior of interacting males can be understood as a system of coupled oscillators. We construct a simple but biologically reasonable model based on the experimental results of two frogs, extend the model to a system of three frogs, and theoretically predict the occurrence of rich synchronization phenomena, such as triphase synchronization and 1:2 antiphase synchronization. In addition, we experimentally verify the theoretical prediction by ethological experiments on the calling behavior of three frogs and time series analysis on recorded sound data. Note that the calling behavior of three male Japanese tree frogs is frustrated because almost perfect antiphase synchronization is robustly observed in a system of two male frogs. Thus, nonlinear dynamics of the three-frogs system should be far from trivial.

  15. Determination of age, longevity and age at reproduction of the frog ...

    Indian Academy of Sciences (India)

    Unknown

    separately in plastic bags and placed in 5 different aquaria. Each frog was anaesthetized (using anaesthetic ether), the body mass and SVL were recorded; the 4th toe of each of the hind limbs was clipped, fixed in 10% formalin and numbered serially. Six large sized frogs were used for skeletochronology of the long bones ...

  16. Flesh fly myiasis (Diptera, Sarcophagidae in Peruvian poison frogs genus Epipedobates (Anura, Dendrobatidae

    Directory of Open Access Journals (Sweden)

    Mattias Hagman

    2005-10-01

    Full Text Available In this note we review records of myiasis in poison frogs collected in various locations in Peru during 1982-2005 and present evidence that larger and medium-sized poison frogs (Epipedobates are infected with sarcophagid fly larvae.

  17. Bacterial flora on Cascades frogs in the Klamath Mountains of California

    Science.gov (United States)

    Karen Pope

    2013-01-01

    Amphibians are experiencing global declines due in part to the infectious disease chytridiomycosis. Some symbiotic bacteria residents on frog skin have been shown to inhibit the growth of Batrachochytrium dendrobatitis (Bd) but few studies have attempted to fully describe the resident bacterial flora of frog skin. We cultured and sequenced 130...

  18. Alkaloids in the mite Scheloribates laevigatus: further alkaloids common to oribatid mites and poison frogs.

    Science.gov (United States)

    Saporito, Ralph A; Norton, Roy A; Andriamaharavo, Nirina R; Garraffo, Hugo Martin; Spande, Thomas F

    2011-02-01

    Poison frogs are chemically defended from predators by diverse alkaloids, almost all of which are sequestered unchanged from alkaloid-containing arthropods in the frog diet. Oribatid mites recently have been proposed as a major dietary source of poison frog alkaloids. Here, we report on alkaloids common to an oribatid mite and poison frogs. Gas chromatographic-mass spectrometric analysis of methanol extracts of adult Scheloribates laevigatus (Oribatida: Scheloribatidae) revealed nine alkaloids. Five of these have been detected previously in the skin glands of poison frogs: two isomers of the pumiliotoxin 291G, two isomers of the 5,6,8-trisubstituted indolizidine 209C, and the 5,6,8-trisubstituted indolizidine 195G. The other four alkaloids, a pumiliotoxin, a tricyclic (coccinelline-like), and two isomers of an izidine, were not previously known, but are similar in structure to alkaloids found in poison frogs. Alkaloids were not detected in immature S. laevigatus, suggesting that they are adult-specific and possibly the result of mite biosynthesis. Although most of the alkaloids detected in S. laevigatus are common to poison frogs, the geographic distributions of these organisms are not sympatric. The findings of this study indicate that oribatid mites, and in particular, members of the genus Scheloribates, represent a relatively unexplored arthropod repository for alkaloids and a significant dietary source of alkaloids in poison frogs.

  19. Phylogeography of Declining Relict and Lowland Leopard Frogs in the Desert Southwest of North America

    Science.gov (United States)

    We investigated the phylogeography of the closely related relict leopard frog (Rana onca) and lowland leopard frog (R. yavapaiensis) – two declining anurans from the warm-desert regions of southwestern North America. We used sequence data from two mitochondrial DNA genes to asses...

  20. Breeding chorus indices are weakly related to estimated abundance of boreal chorus frogs

    Science.gov (United States)

    Paul Stephen Corn; Erin Muths; Amanda M. Kissel; Rick D. Scherer

    2011-01-01

    Call surveys used to monitor breeding choruses of anuran amphibians generate index values that are frequently used to represent the number of male frogs present, but few studies have quantified this relationship. We compared abundance of male Boreal Chorus Frogs (Pseudacris maculata), estimated using capture-recapture methods in two populations in Colorado, to call...

  1. Prevalence of endo-parasites of common tree frog Rana saharica ...

    African Journals Online (AJOL)

    The current study was conducted to detect the prevalence of parasitic infection among (62) common tree frogs (Rana Saharica), of different ages, with weights ranged between 1 and 25g. Results: The results revealed that 61 (98%) out of 62 examined common frogs were infected with endo-parasites. The prevalence of ...

  2. How the environment shapes animal signals: a test of the acoustic adaptation hypothesis in frogs.

    Science.gov (United States)

    Goutte, S; Dubois, A; Howard, S D; Márquez, R; Rowley, J J L; Dehling, J M; Grandcolas, P; Xiong, R C; Legendre, F

    2018-01-01

    Long-distance acoustic signals are widely used in animal communication systems and, in many cases, are essential for reproduction. The acoustic adaptation hypothesis (AAH) implies that acoustic signals should be selected for further transmission and better content integrity under the acoustic constraints of the habitat in which they are produced. In this study, we test predictions derived from the AAH in frogs. Specifically, we focus on the difference between torrent frogs and frogs calling in less noisy habitats. Torrents produce sounds that can mask frog vocalizations and constitute a major acoustic constraint on call evolution. We combine data collected in the field, material from scientific collections and the literature for a total of 79 primarily Asian species, of the families Ranidae, Rhacophoridae, Dicroglossidae and Microhylidae. Using phylogenetic comparative methods and including morphological and environmental potential confounding factors, we investigate putatively adaptive call features in torrent frogs. We use broad habitat categories as well as fine-scale habitat measurements and test their correlation with six call characteristics. We find mixed support for the AAH. Spectral features of torrent frog calls are different from those of frogs calling in other habitats and are related to ambient noise levels, as predicted by the AAH. However, temporal call features do not seem to be shaped by the frogs' calling habitats. Our results underline both the complexity of call evolution and the need to consider multiple factors when investigating this issue. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  3. Propulsive force calculations in swimming frogs I. A momentum-impulse approach

    NARCIS (Netherlands)

    Nauwelaerts, S; Stamhuis, EJ; Aerts, P

    Frogs are animals that are capable of locomotion in two physically different media, aquatic and terrestrial. A comparison of the kinematics of swimming frogs in a previous study revealed a difference in propulsive impulse between jumping and swimming. To explore this difference further, we

  4. Propulsive force calculations in swimming frogs II. Application of a vortex ring model to DPIV data

    NARCIS (Netherlands)

    Stamhuis, E.J.; Nauwelaerts, S.

    Frogs propel themselves by kicking water backwards using a synchronised extension of their hind limbs and webbed feet. To understand this propulsion process, we quantified the water movements and displacements resulting from swimming in the green frog Rana esculenta, applying digital particle image

  5. The toxicity of Poison Dart Frog alkaloids against the Fire Ant (Solenopsis invicta)

    Science.gov (United States)

    Hundreds of alkaloids, representing over 20 structural classes, have been identified from the skin of neotropical poison frogs (Dendrobatidae). These alkaloids are derived from arthropod prey of the frogs, and are generally are believed to deter vertebrate predators. We developed a method to put ind...

  6. Population estimates for the Toiyabe population of the Columbia spotted frog (Rana luteiventris), 2004–10

    Science.gov (United States)

    Adams, Michael J.; Mellison, Chad; Galvan, Stephanie K.

    2013-01-01

    The Toiyabe population of Columbia spotted frogs (Rana luteiventris, hereafter "Toiyabe frogs") is a geographically isolated population located in central Nevada (fig. 1). The Toiyabe population is part of the Great Basin Distinct Population Segment of Columbia spotted frogs, and is a candidate for listing under the Endangered Species Act (U.S. Fish and Wildlife Service, 2011). The cluster of breeding sites in central Nevada represents the southernmost extremity of the Columbia spotted frogs' known range (Funk and others, 2008). Toiyabe frogs are known to occur in seven drainages in Nye County, Nevada: Reese River, Cow Canyon Creek, Ledbetter Canyon Creek, Cloverdale Creek, Stewart Creek, Illinois Creek, and Indian Valley Creek. Most of the Toiyabe frog population resides in the Reese River, Indian Valley Creek, and Cloverdale Creek drainages (fig. 1; Nevada Department of Wildlife, 2003). Approximately 90 percent of the Toiyabe frogs' habitat is on public land. Most of the public land habitat (95 percent) is managed by the U.S. Forest Service (USFS), while the Bureau of Land Management (BLM) manages the remainder. Additional Toiyabe frog habitat is under Yomba Shoshone Tribal management and in private ownership (Nevada Department of Wildlife, 2003). The BLM, USFS, Nevada Department of Wildlife (NDOW), Nevada Natural Heritage Program (NNHP), Nye County, and U.S Fish and Wildlife Service (USFWS) have monitored the Toiyabe population since 2004 using mark and recapture surveys (Nevada Department of Wildlife, 2004). The USFWS contracted with the U.S. Geological Survey (USGS) to produce population estimates using these data.

  7. Helminth Community of Tree frogs at the Okomu National Park, Edo ...

    African Journals Online (AJOL)

    The tree frogs of the Okomu National Park were investigated for their helminth parasitic infections. The 24 species of tree frogs encountered belonged to the families Arthroleptidae, Hyperoliidae, Ranidae and Rhacophoridae. The helminth parasites encountered in the study included: Cestoda: Baerietta sp. (7.4%); ...

  8. Effects of increasing temperature and, CO2 on quality of litter, shredders, and microorganisms in Amazonian aquatic systems.

    Directory of Open Access Journals (Sweden)

    Renato Tavares Martins

    Full Text Available Climate change may affect the chemical composition of riparian leaf litter and, aquatic organisms and, consequently, leaf breakdown. We evaluated the effects of different scenarios combining increased temperature and carbon dioxide (CO2 on leaf detritus of Hevea spruceana (Benth Müll. and decomposers (insect shredders and microorganisms. We hypothesized that simulated climate change (warming and elevated CO2 would: i decrease leaf-litter quality, ii decrease survival and leaf breakdown by shredders, and iii increase microbial leaf breakdown and fungal biomass. We performed the experiment in four microcosm chambers that simulated air temperature and CO2 changes in relation to a real-time control tracking current conditions in Manaus, Amazonas, Brazil. The experiment lasted seven days. During the experiment mean air temperature and CO2 concentration ranged from 26.96 ± 0.98ºC and 537.86 ± 18.36 ppmv in the control to 31.75 ± 0.50ºC and 1636.96 ± 17.99 ppmv in the extreme chamber, respectively. However, phosphorus concentration in the leaf litter decreased with warming and elevated CO2. Leaf quality (percentage of carbon, nitrogen, phosphorus, cellulose and lignin was not influenced by soil flooding. Fungal biomass and microbial leaf breakdown were positively influenced by temperature and CO2 increase and reached their highest values in the intermediate condition. Both total and shredder leaf breakdown, and shredder survival rate were similar among all climatic conditions. Thus, low leaf-litter quality due to climate change and higher leaf breakdown under intermediate conditions may indicate an increase of riparian metabolism due to temperature and CO2 increase, highlighting the risk (e.g., decreased productivity of global warming for tropical streams.

  9. Effects of increasing temperature and, CO2 on quality of litter, shredders, and microorganisms in Amazonian aquatic systems.

    Science.gov (United States)

    Martins, Renato Tavares; Rezende, Renan de Souza; Gonçalves Júnior, José Francisco; Lopes, Aline; Piedade, Maria Teresa Fernandez; Cavalcante, Heloide de Lima; Hamada, Neusa

    2017-01-01

    Climate change may affect the chemical composition of riparian leaf litter and, aquatic organisms and, consequently, leaf breakdown. We evaluated the effects of different scenarios combining increased temperature and carbon dioxide (CO2) on leaf detritus of Hevea spruceana (Benth) Müll. and decomposers (insect shredders and microorganisms). We hypothesized that simulated climate change (warming and elevated CO2) would: i) decrease leaf-litter quality, ii) decrease survival and leaf breakdown by shredders, and iii) increase microbial leaf breakdown and fungal biomass. We performed the experiment in four microcosm chambers that simulated air temperature and CO2 changes in relation to a real-time control tracking current conditions in Manaus, Amazonas, Brazil. The experiment lasted seven days. During the experiment mean air temperature and CO2 concentration ranged from 26.96 ± 0.98ºC and 537.86 ± 18.36 ppmv in the control to 31.75 ± 0.50ºC and 1636.96 ± 17.99 ppmv in the extreme chamber, respectively. However, phosphorus concentration in the leaf litter decreased with warming and elevated CO2. Leaf quality (percentage of carbon, nitrogen, phosphorus, cellulose and lignin) was not influenced by soil flooding. Fungal biomass and microbial leaf breakdown were positively influenced by temperature and CO2 increase and reached their highest values in the intermediate condition. Both total and shredder leaf breakdown, and shredder survival rate were similar among all climatic conditions. Thus, low leaf-litter quality due to climate change and higher leaf breakdown under intermediate conditions may indicate an increase of riparian metabolism due to temperature and CO2 increase, highlighting the risk (e.g., decreased productivity) of global warming for tropical streams.

  10. Radioautographic and histologic investigation of skin in young and old frogs

    International Nuclear Information System (INIS)

    Koo, Kook Bon; You, Dong Soo

    1983-01-01

    Age differences in the skin structure have been studied in young (one year-old) and aged (five and a half year- old) frogs, Xenopus laevis. The epidermis in young frogs is made up of an average of 6.3 and 4.7 layers of epithelial cells at abdominal and dorsal surfaces, respectively. In aged frogs, the number of respective cell layers at abdominal and dorsal surfaces increases to 8.8 and 5.6. The thickness of the dermis (spongiosum) in aged frogs is decrease d 25% on the abdominal side (from 267 μm to 207 μm) but is increased by 11% on the dorsal side (from 275 μm to 305 μm). The nucleolar index and 3H-uridine incorporation, as judged by radioautography, by epithelial cells are drastically reduced in aged frogs.

  11. Isolation of Brucella inopinata-Like Bacteria from White's and Denny's Tree Frogs.

    Science.gov (United States)

    Kimura, Masanobu; Une, Yumi; Suzuki, Michio; Park, Eun-Sil; Imaoka, Koichi; Morikawa, Shigeru

    2017-05-01

    Brucella inopinata strain BO1 and B. sp. strain BO2 isolated from human patients, respectively, are genetically different from classical Brucella species. We isolated bacteria of the genus Brucella from two species of wild-caught tropical frogs kept in the facilities in Japan: White's tree frog, which inhabits Oceania, and Denny's tree frog, which inhabits Southeast Asia. Phylogenetic analyses based on 16S rRNA and recA gene sequences and multilocus sequence analysis showed that two isolates of Brucella spp. showed significant similarity to BO1, BO2, and the isolates from other wild-caught frogs. These results suggest that a variety of frog species are susceptible to a novel clade of Brucella bacteria, including B. inopinata.

  12. Frankixalus, a New Rhacophorid Genus of Tree Hole Breeding Frogs with Oophagous Tadpoles.

    Directory of Open Access Journals (Sweden)

    S D Biju

    Full Text Available Despite renewed interest in the biogeography and evolutionary history of Old World tree frogs (Rhacophoridae, this family still includes enigmatic frogs with ambiguous phylogenetic placement. During fieldwork in four northeastern states of India, we discovered several populations of tree hole breeding frogs with oophagous tadpoles. We used molecular data, consisting of two nuclear and three mitochondrial gene fragments for all known rhacophorid genera, to investigate the phylogenetic position of these new frogs. Our analyses identify a previously overlooked, yet distinct evolutionary lineage of frogs that warrants recognition as a new genus and is here described as Frankixalus gen. nov. This genus, which contains the enigmatic 'Polypedates' jerdonii described by Günther in 1876, forms the sister group of a clade containing Kurixalus, Pseudophilautus, Raorchestes, Mercurana and Beddomixalus. The distinctiveness of this evolutionary lineage is also corroborated by the external morphology of adults and tadpoles, adult osteology, breeding ecology, and life history features.

  13. Abundance of green tree frogs and insects in artificial canopy gaps in a bottomland hardwood forest.

    Energy Technology Data Exchange (ETDEWEB)

    Horn, Scott; Hanula, James L.; Ulyshen, Michael D.; Kilgo, John C.

    2005-01-01

    Horn, Scott, James L. Hanula, Michael D. Ulyshen, and John C. Kilgo. 2005. Abundance of green tree frogs and insects in artificial canopy gaps in a bottomland hardwood forest. Am. Midl. Nat. 153:321-326. Abstract: We found more green tree frogs (Hyla cinerea) in canopy gaps than in closed canopy forest. Of the 331 green tree frogs observed, 88% were in canopy gaps. Likewise, higher numbers and biomasses of insects were captured in the open gap habitat. Flies were the most commonly collected insect group accounting for 54% of the total capture. These data suggest that one reason green tree frogs were more abundant in canopy gaps was the increased availability of prey and that small canopy gaps provide early successional habitats that are beneficial to green tree frog populations.

  14. Functional evolution of jumping in frogs: Interspecific differences in take-off and landing.

    Science.gov (United States)

    Reilly, Stephen M; Montuelle, Stephane J; Schmidt, André; Krause, Cornelia; Naylor, Emily; Essner, Richard L

    2016-03-01

    Ancestral frogs underwent anatomical shifts including elongation of the hindlimbs and pelvis and reduction of the tail and vertebral column that heralded the transition to jumping as a primary mode of locomotion. Jumping has been hypothesized to have evolved in a step-wise fashion with basal frogs taking-off with synchronous hindlimb extension and crash-landing on their bodies, and then their limbs move forward. Subsequently, frogs began to recycle the forelimbs forward earlier in the jump to control landing. Frogs with forelimb landing radiated into many forms, locomotor modes, habitats, and niches with controlled landing thought to improve escape behavior. While the biology of take-off behavior has seen considerable study, interspecific comparisons of take-off and landing behavior are limited. In order to understand the evolution of jumping and controlled landing in frogs, data are needed on the movements of the limbs and body across an array of taxa. Here, we present the first description and comparison of kinematics of the hindlimbs, forelimbs and body during take-off and landing in relation to ground reaction forces in four frog species spanning the frog phylogeny. The goal of this study is to understand what interspecific differences reveal about the evolution of take-off and controlled landing in frogs. We provide the first comparative description of the entire process of jumping in frogs. Statistical comparisons identify both homologous behaviors and significant differences among species that are used to map patterns of trait evolution and generate hypotheses regarding the functional evolution of take-off and landing in frogs. © 2015 Wiley Periodicals, Inc.

  15. Dynamics of testis-ova in a wild population of Japanese pond frogs, Rana nigromaculata.

    Science.gov (United States)

    Kobayashi, Tohru; Kumakura, Masahiko; Yoshie, Sumio; Sugishima, Tomomi; Horie, Yoshifumi

    2015-02-01

    Although many studies have reported the occurrence of testis-ova in wild frog populations, the origin and trigger of testis-ova differentiation/development remain unclear. A high frequency of testis-ova has been previously reported for wild populations of the Japanese pond frog, Rana nigromaculata (cf. Iwasawa and Asai, '59). In the present study, we aimed to clarify the dynamics of testis-ova in this frog species, including the origin and artificial induction of testis-ova. Testis-ova were observed in both mature frogs and puberty-stage frogs (i.e., 0- and 1-year-old frogs). However, the early stages of testis-ova (~pachytene stage) were mostly observed in puberty-stage male frogs at the onset of spermatogenesis. The early stages of testis-ova were observed in the cysts of early secondary spermatogonia and the single cysts of the primary spermatogonium. This finding indicates that testis-ova differentiation occurs during spermatogonial proliferation and that it is correlated with the initiation of spermatogenesis. We also examined whether estrogen exposure induced testis-ova differentiation and how it is correlated with the progression of spermatogenesis. When 1-year-old frogs were exposed to estradiol-17β during spring (i.e., when spermatogenesis was initiated), testis-ova differentiation was induced in a dose-dependent manner. However, this phenomenon did not occur in 1-year-old frogs during summer, (i.e., when the transition from spermatogonia to spermatocytes mainly occurs). These results present the first evidence that testis-ova of the Japanese pond frog are derived from primary and early secondary spermatogonia, and that estrogen exposure induces testis-ova differentiation accompanied by the initiation of spermatogenesis. © 2015 Wiley Periodicals, Inc.

  16. Which frog's legs do froggies eat? The use of DNA barcoding for identification of deep frozen frog legs (Dicroglossidae, Amphibia commercialized in France

    Directory of Open Access Journals (Sweden)

    Annemarie Ohler

    2017-02-01

    Full Text Available Several millions frogs captured in the wild in Indonesia are sold for food yearly in French supermarkets, as deep frozen frog legs. They are commercialized as Rana macrodon, but up to 15 look-alike species might also be concerned by this trade. From December 2012 to May 2013, we bought 209 specimens of deep frozen frog legs, and identified them through a barcoding approach based on the 16S gene. Our results show that 206 out of the 209 specimens belong to Fejervarya cancrivora, two to Limnonectes macrodon and one to F. moodiei. Thus only 0.96 % of the frogs were correctly identified. Unless misclassification was intentional, it seems that Indonesian frog leg exporters are not able to discriminate between the species. The quasi absence of L. macrodon in our samples might be an indication of its rarity, confirming that its natural populations are declining rapidly, in agreement with its “vulnerable” status according to the IUCN Red List. Our results show that the genetic and morphological diversity of the frogs in trade is much higher than the genetic and morphological diversity measured so far by scientific studies. These results underline the need for large scale studies to assess the status of wild populations.

  17. Biogeography and evolution of Amazonian triatomines (Heteroptera: Reduviidae: implications for Chagas disease surveillance in humid forest ecoregions

    Directory of Open Access Journals (Sweden)

    Fernando Abad-Franch

    2007-10-01

    Full Text Available An ecological-evolutionary classification of Amazonian triatomines is proposed based on a revision of their main contemporary biogeographical patterns. Truly Amazonian triatomines include the Rhodniini, the Cavernicolini, and perhaps Eratyrus and some Bolboderini. The tribe Rhodniini comprises two major lineages (pictipes and robustus. The former gave rise to trans-Andean (pallescens and Amazonian (pictipes species groups, while the latter diversified within Amazonia (robustus group and radiated to neighbouring ecoregions (Orinoco, Cerrado-Caatinga-Chaco, and Atlantic Forest. Three widely distributed Panstrongylus species probably occupied Amazonia secondarily, while a few Triatoma species include Amazonian populations that occur only in the fringes of the region. T. maculata probably represents a vicariant subset isolated from its parental lineage in the Caatinga-Cerrado system when moist forests closed a dry trans-Amazonian corridor. These diverse Amazonian triatomines display different degrees of synanthropism, defining a behavioural gradient from household invasion by adult triatomines to the stable colonisation of artificial structures. Anthropogenic ecological disturbance (driven by deforestation is probably crucial in the onset of the process, but the fact that only a small fraction of species effectively colonises artificial environments suggests a role for evolution at the end of the gradient. Domestic infestation foci are restricted to drier subregions within Amazonia; thus, populations adapted to extremely humid rainforest microclimates may have limited chances of successfully colonising the slightly drier artificial microenvironments. These observations suggest several research avenues, from the use of climate data to map risk areas to the assessment of the synanthropic potential of individual vector species.

  18. Isolation and identification of intestinal bacteria from Japanese tree frog (Hlya japonica) with the special reference to anaerobic bacteria.

    Science.gov (United States)

    Benno, Y; Izumi-Kurotani, A; Yamashita, M

    1992-08-01

    The bacteria in the large intestines of eight Japanese tree frogs (Hlya japonica) were enumerated by using an anaerobic culture system. The microorganisms at approximately 3.1 x 10(9) bacteria per g (wet weight) of intestinal contents were present in the intestine of all the frogs tested. No difference of the total bacteria in the frog intestine was observed between two different incubation-temperatures (room temperature and 37 degrees C). Eleven genera and 16 species were isolated from the frog intestine. In most frogs, Bacteroides (B.) caccae and B. vulgatus were detected as the predominant organisms. Escherichia coli was also present in greater numbers in the intestine. Other bacteria isolated at high dilutions were strict anaerobes, including Fusobacterium and Clostridium. Enterococcus faecalis was frequently isolated from the frog intestine. However, four genera of Bifidobacterium, Eubacterium, Peptostreptococcus, and Lactobacillus were not isolated from the frog intestine.

  19. The Tsimane' Amazonian Panel Study (TAPS): Nine years (2002-2010) of annual data available to the public.

    Science.gov (United States)

    Leonard, William R; Reyes-García, Victoria; Tanner, Susan; Rosinger, Asher; Schultz, Alan; Vadez, Vincent; Zhang, Rebecca; Godoy, Ricardo

    2015-12-01

    This brief communication contains a description of the 2002-2010 annual panel collected by the Tsimane' Amazonian Panel Study team. The study took place among the Tsimane', a native Amazonian society of forager-horticulturalists. The team tracked a wide range of socio-economic and anthropometric variables from all residents (633 adults ≥16 years; 820 children) in 13 villages along the Maniqui River, Department of Beni. The panel is ideally suited to examine how market exposure and modernization affect the well-being of a highly autarkic population and to examine human growth in a non-Western rural setting. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Amazonian-aged fluvial system and associated ice-related features in Terra Cimmeria, Mars

    Science.gov (United States)

    Adeli, Solmaz; Hauber, Ernst; Kleinhans, Maarten; Le Deit, Laetitia; Platz, Thomas; Fawdon, Peter; Jaumann, Ralf

    2016-10-01

    The Martian climate throughout the Amazonian is widely believed to have been cold and hyper-arid, very similar to the current conditions. However, ubiquitous evidence of aqueous and glacial activity has been recently reported, including channels that can be tens to hundreds of kilometres long, alluvial and fluvial deposits, ice-rich mantles, and glacial and periglacial landforms. Here we study a ∼340 km-long fluvial system located in the Terra Cimmeria region, in the southern mid-latitudes of Mars. The fluvial system is composed of an upstream catchment system with narrow glaciofluvial valleys and remnants of ice-rich deposits. We observe depositional features including fan-shaped deposits, and erosional features such as scour marks and streamlined islands. At the downstream section of this fluvial system is an outflow channel named Kārūn Valles, which displays a unique braided alluvial fan and terminates on the floor of the Ariadnes Colles basin. Our observations point to surface runoff of ice/snow melt as the water source for this fluvial activity. According to our crater size-frequency distribution analysis the entire fluvial system formed during early to middle Amazonian, between ∼ 1.8-0.2+0.2 Ga to 510-40+40 Ma. Hydraulic modelling indicates that the Kārūn Valles and consequently the alluvial fan formation took place in geologically short-term event(s). We conclude that liquid water was present in Terra Cimmeria during the early to middle Amazonian, and that Mars during that time may have undergone several episodic glacial-related events.

  1. Physical growth of the shuar: Height, Weight, and BMI references for an indigenous amazonian population.

    Science.gov (United States)

    Urlacher, Samuel S; Blackwell, Aaron D; Liebert, Melissa A; Madimenos, Felicia C; Cepon-Robins, Tara J; Gildner, Theresa E; Snodgrass, J Josh; Sugiyama, Lawrence S

    2016-01-01

    Information concerning physical growth among small-scale populations remains limited, yet such data are critical to local health efforts and to foster basic understandings of human life history and variation in childhood development. Using a large dataset and robust modeling methods, this study aims to describe growth from birth to adulthood among the indigenous Shuar of Amazonian Ecuador. Mixed-longitudinal measures of height, weight, and body mass index (BMI) were collected from Shuar participants (n = 2,463; age: 0-29 years). Centile growth curves and tables were created for each anthropometric variable of interest using Generalized Additive Models for Location, Scale, and Shape (GAMLSS). Pseudo-velocity and Lambda-Mu-Sigma curves were generated to further investigate Shuar patterns of growth and to facilitate comparison with United States Center for Disease Control and Prevention and multinational World Health Organization growth references. The Shuar are small throughout life and exhibit complex patterns of growth that differ substantially from those of international references. Similar to other Amazonians, Shuar growth in weight compares more favorably to references than growth in height, resulting in BMI curves that approximate international medians. Several additional characteristics of Shuar development are noteworthy, including large observed variation in body size early in life, significant infant growth faltering, extended male growth into adulthood, and a markedly early female pubertal growth spurt in height. Phenotypic plasticity and genetic selection in response to local environmental factors may explain many of these patterns. Providing a detailed reference of growth for the Shuar and other Amazonian populations, this study possesses direct clinical application and affords valuable insight into childhood health and the ecology of human growth. © 2015 Wiley Periodicals, Inc.

  2. Fish are central in the diet of Amazonian riparians: should we worry about their mercury concentrations?

    International Nuclear Information System (INIS)

    Dorea, Jose G.

    2003-01-01

    The Amazon rain forest extends over an area of 7.8x10 6 km 2 in nine countries. It harbors a diverse human population distributed in dense cities and isolated communities with extreme levels of infrastructure. Amazonian forest people, either autochthons or frontier riparians (ribeirinhos) living in isolated areas, share the same environment for survival and nutritional status. The peculiarities of the hydrological cycle determine disease patterns, agricultural conditions, and food availability. Feeding strategies depend heavily on cassava products and fish. These two foods carry toxic substances such as linamarin (naturally present in cassava) and monomethyl mercury (MMHg) (bioconcentrated in fish flesh) that cause neurotoxic diseases in other parts of the world but not in Amazonia, where neurotoxic cases of food origin are rare and not related to these staples. While cassava detoxification processes may partly explain its safe consumption, the Hg concentrations in Amazonian fish are within traditionally safe limits for this population and contribute to an important metabolic interaction with cassava. The gold rush of the 1970s and 1980s brought large-scale environmental disruption and physical destruction of ecosystems at impact points, along with a heavy discharge of metallic Hg. The discharged Hg has not yet impacted on MMHg concentrations in fish or in hair of fish consumers. Hair Hg concentration, used as a biomarker of fish consumption, indicates that the Amazonian riparians are acquiring an excellent source of protein carrying important nutrients, the lack of which could aggravate their existing health problems. Therefore, in a scenario of insufficient health services and an unhealthy environment, food habits based on fish consumption are part of a successful survival strategy and recommendations for changes are not yet justifiable

  3. Costs and benefits of simulating the hydro-climatological effects of Amazonian deforestation at different resolutions

    Science.gov (United States)

    Khanna, J.; Medvigy, D.

    2013-12-01

    The hydro-climatological effects of Amazonian deforestation have been found to be scale dependent. On one hand GCM studies of deforestation at resolutions >1° and scales 1000 km simulate reduced precipitation over deforested areas, while some observations and RCM studies show an increase in convective activity and precipitation over cleared patches of scales less than 10 km. It is suggested that mesoscale circulations, called ';land breezes', that develop at these small scales of deforestation are responsible for the significant increase in cloud cover and rain. This phenomenon is not captured at the coarse resolution in GCMs. This scale mismatch between GCMs and observed physical processes has to be addressed in modeling studies in order to make realistic inferences for contemporary and future deforestation. One solution is to simulate land breezes in the Amazon at high resolutions exploiting the power of modern high performance computing. But the spatial scales and model resolutions at which mesoscale circulations start to appear and disappear are not well understood. Therefore it is desirable to systematically study the trade off between the computational cost of increased resolution and the resultant information gain. The present study, the first of its kind, formally delves into this problem. The variable resolution Ocean-Land-Atmosphere-Model (OLAM) is used to simulate the hydro-climatic effects of Amazonian deforestation. A cost-benefit analysis is done using different atmospheric initializations to drive the model over a suite of spatial resolutions. High-resolution simulations, informed by the cost-benefit analysis, are performed to estimate the climatically important spatial scales of Amazonian deforestation. Preliminary results from this analysis will be presented.

  4. Elements of metacommunity structure in Amazonian Zygoptera among streams under different spatial scales and environmental conditions.

    Science.gov (United States)

    Brasil, Leandro Schlemmer; Vieira, Thiago Bernardi; de Oliveira-Junior, José Max Barbosa; Dias-Silva, Karina; Juen, Leandro

    2017-05-01

    An important aspect of conservation is to understand the founding elements and characteristics of metacommunities in natural environments, and the consequences of anthropogenic disturbance on these patterns. In natural Amazonian environments, the interfluves of the major rivers play an important role in the formation of areas of endemism through the historical isolation of species and the speciation process. We evaluated elements of metacommunity structure for Zygoptera (Insecta: Odonata) sampled in 93 Amazonian streams distributed in two distinct biogeographic regions (areas of endemism). Of sampled streams, 43 were considered to have experienced negligible anthropogenic impacts, and 50 were considered impacted by anthropogenic activities. Our hypothesis was that preserved ("negligible impact") streams would present a Clementsian pattern, forming clusters of distinct species, reflecting the biogeographic pattern of the two regions, and that anthropogenic streams would present random patterns of metacommunity, due to the loss of more sensitive species and dominance of more tolerant species, which have higher dispersal ability and environmental tolerance. In negligible impact streams, the Clementsian pattern reflected a strong biogeographic pattern, which we discuss considering the areas of endemism of Amazonian rivers. As for communities in human-impacted streams, a biotic homogenization was evident, in which rare species were suppressed and the most common species had become hyper-dominant. Understanding the mechanisms that trigger changes in metacommunities is an important issue for conservation, because they can help create mitigation measures for the impacts of anthropogenic activities on biological communities, and so should be expanded to studies using other taxonomic groups in both tropical and temperate systems, and, wherever possible, at multiple spatial scales.

  5. Taxonomy Icon Data: Japanese tree frog [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available Japanese tree frog Hyla japonica Chordata/Vertebrata/Amphibia Hyla_japonica_L.png Hyla_jap...onica_NL.png Hyla_japonica_S.png Hyla_japonica_NS.png http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Hyla+jap...onica&t=L http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Hyla+japonica&t=NL http://biosciencedbc....jp/taxonomy_icon/icon.cgi?i=Hyla+japonica&t=S http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Hyla+jap

  6. Alkaloid 223A: the first trisubstituted indolizidine from dendrobatid frogs.

    Science.gov (United States)

    Garraffo, H M; Jain, P; Spande, T F; Daly, J W

    1997-01-01

    The structure of alkaloid 223A (1), the first member of a new class of amphibian alkaloids, purified by HPLC from a skin extract of a Panamanian population of the frog Dendrobates pumilio Schmidt (Dendrobatidae) has been established as (5R,6S,8R,9S)- or (5S,6R,8S,9R)-6,8-diethyl-5-propylindolizidine, based on GC-MS, GC-FTIR, and 1H-NMR spectral studies. Three higher homologs of 223A, namely alkaloids 237L (2), 251M (3), and 267J (4), have been detected in other extracts, and tentative structures are proposed.

  7. Natural infection of Lutzomyia tortura with Leishmania (Viannia) naiffi in an Amazonian area of Ecuador.

    Science.gov (United States)

    Kato, Hirotomo; Gomez, Eduardo A; Yamamoto, Yu-ichi; Calvopiña, Manuel; Guevara, Angel G; Marco, Jorge D; Barroso, Paola A; Iwata, Hiroyuki; Hashiguchi, Yoshihisa

    2008-09-01

    Natural infection of sand flies with Leishmania parasites was surveyed in an Amazonian area in Ecuador where leishmaniasis is endemic. Seventy-one female sand flies were dissected and one was positive for Leishmania protozoa. The species of this sand fly was identified as Lutzomyia (Lu.) tortura on the basis of morphologic characteristics. Analysis of the cytochrome b gene sequence identified the parasite as L. (Viannia) naiffi. We report the distribution of L. (V.) naiffi in Ecuador and detection of a naturally infected sand fly in the Ecuadorian Amazon and natural infection of Lu. tortura with Leishmania parasites in the New World.

  8. Sulfur and lead isotope characteristics of the Pontes e Lacerda gold deposits, SW Amazonian Craton Brazil

    International Nuclear Information System (INIS)

    Geraldes, M.C.; Tassinari, C.C.G.; Babinski; M; Iyer, S

    2001-01-01

    This work deals with the characterization of the S and Pb isotope signatures in sulfides from the Pontes e Lacerda mesothermal gold deposits located in the SW sector of Amazonian craton. Stable and radiogenic isotopes have played an important role in the study of ore deposited and hydrothermal processes and they are most useful when can be used together. The purpose of this study is to constrain the sources and the mechanisms of gold deposition in Pontes e Lacerda region which may be a helpful contribution to an exploratory model in the area (au)

  9. Cytogenetic description of the Amazonian brown brocket Mazama nemorivaga (Artiodactyla, Cervidae)

    OpenAIRE

    Fiorillo,Bruno Ferreto; Sarria-Perea,Javier Adolfo; Abril,VanessaVeltrini; Duarte,José Maurício Barbanti

    2013-01-01

    The Amazonian brown brocket Mazama nemorivaga (Cuvier, 1817) is a small to medium-sized deer from the Amazon rainforest and ecotones. The first karyotype described was 2n=67 to 69 + 2-7 B and FN= 69-72, in which all chromosomes were acrocentric and the X chromosome was the only submetacentric chromosome. However, important aspects of the species chromosome evolution were not resolved because of the lack of information on chromosome banding. The G-banding pattern of M. nemorivaga karyotype sho...

  10. Characterisation of acid-soluble and pepsin-solubilised collagen from frog (Rana nigromaculata) skin.

    Science.gov (United States)

    Zhang, Junjie; Duan, Rui

    2017-08-01

    As the first vertebrates connecting water and land, frogs must have evolved certain specialisations. To find the difference among the collagens from amphibian, fish and mammal animals, acid-soluble collagen (ASC) and pepsin-solubilised collagen (PSC) from frog skin were isolated and characterised. The yield of PSC (19.59%, dry weight) was higher than that of ASC (1.83%, dry weight). The hydroxyproline-to-protein ratio of frog skin was 8.37%, which was higher than that of carp skin ASC (7.83%) but significantly lower than that of calf skin collagen (10.16%), which was in accordance with the living environment of frog. The denaturation temperature of frog skin collagens was approximately 31.5°C. The SDS-PAGE electrophoresis revealed that ASC and PSC were type I collagens. Fourier transform infrared spectroscopy proved that the ASC and PSC retained their helical structures. The results indicated the properties of frog skin collagen were close to those of skin collagen from freshwater fish. The frog skin collagens can potentially be used in biomaterial and other fields. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Environmental and Host Effects on Skin Bacterial Community Composition in Panamanian Frogs.

    Science.gov (United States)

    Varela, Brandon J; Lesbarrères, David; Ibáñez, Roberto; Green, David M

    2018-01-01

    Research on the amphibian skin microbiota has focused on identifying bacterial taxa that deter a pathogenic chytrid fungus, and on describing patterns of microbiota variation. However, it remains unclear how environmental variation affects amphibian skin bacterial communities, and whether the overall functional diversity of the amphibian skin microbiota is associated to such variation. We sampled skin microbial communities from one dendrobatoid frog species across an environmental gradient along the Panama Canal, and from three dendrobatoid frog species before and after the onset of the wet season in one site. We found frog skin microbial alpha diversity to be highest in frogs from sites with low soil pH, but no clear effect of the onset of the wet season. However, we found frog skin microbial community structure to be affected by soil pH and the onset of the wet season, which also resulted in a decrease in between-sample variation. Across the sampled frog species, bacterial functional groups changed with the onset of the wet season, with certain bacterial functional groups entirely disappearing and others differing in their relative abundances. In particular, we found the proportion of Bd-inhibitory bacteria to correlate with mean soil pH, and to increase in two of the frog species with the onset of the wet season. Taken together, our results suggest that structure and predicted function of amphibian bacterial skin communities may be influenced by environmental variables such as pH and precipitation, site effects, and host effects.

  12. Poison frog colors are honest signals of toxicity, particularly for bird predators.

    Science.gov (United States)

    Maan, Martine E; Cummings, Molly E

    2012-01-01

    Antipredator defenses and warning signals typically evolve in concert. However, the extensive variation across taxa in both these components of predator deterrence and the relationship between them are poorly understood. Here we test whether there is a predictive relationship between visual conspicuousness and toxicity levels across 10 populations of the color-polymorphic strawberry poison frog, Dendrobates pumilio. Using a mouse-based toxicity assay, we find extreme variation in toxicity between frog populations. This variation is significantly positively correlated with frog coloration brightness, a viewer-independent measure of visual conspicuousness (i.e., total reflectance flux). We also examine conspicuousness from the view of three potential predator taxa, as well as conspecific frogs, using taxon-specific visual detection models and three natural background substrates. We find very strong positive relationships between frog toxicity and conspicuousness for bird-specific perceptual models. Weaker but still positive correlations are found for crab and D. pumilio conspecific visual perception, while frog coloration as viewed by snakes is not related to toxicity. These results suggest that poison frog colors can be honest signals of prey unpalatability to predators and that birds in particular may exert selection on aposematic signal design. © 2011 by The University of Chicago.

  13. Chasing maximal performance: a cautionary tale from the celebrated jumping frogs of Calaveras County.

    Science.gov (United States)

    Astley, H C; Abbott, E M; Azizi, E; Marsh, R L; Roberts, T J

    2013-11-01

    Maximal performance is an essential metric for understanding many aspects of an organism's biology, but it can be difficult to determine because a measured maximum may reflect only a peak level of effort, not a physiological limit. We used a unique opportunity provided by a frog jumping contest to evaluate the validity of existing laboratory estimates of maximum jumping performance in bullfrogs (Rana catesbeiana). We recorded video of 3124 bullfrog jumps over the course of the 4-day contest at the Calaveras County Jumping Frog Jubilee, and determined jump distance from these images and a calibration of the jump arena. Frogs were divided into two groups: 'rental' frogs collected by fair organizers and jumped by the general public, and frogs collected and jumped by experienced, 'professional' teams. A total of 58% of recorded jumps surpassed the maximum jump distance in the literature (1.295 m), and the longest jump was 2.2 m. Compared with rental frogs, professionally jumped frogs jumped farther, and the distribution of jump distances for this group was skewed towards long jumps. Calculated muscular work, historical records and the skewed distribution of jump distances all suggest that the longest jumps represent the true performance limit for this species. Using resampling, we estimated the probability of observing a given jump distance for various sample sizes, showing that large sample sizes are required to detect rare maximal jumps. These results show the importance of sample size, animal motivation and physiological conditions for accurate maximal performance estimates.

  14. Environmental and Host Effects on Skin Bacterial Community Composition in Panamanian Frogs

    Directory of Open Access Journals (Sweden)

    Brandon J. Varela

    2018-02-01

    Full Text Available Research on the amphibian skin microbiota has focused on identifying bacterial taxa that deter a pathogenic chytrid fungus, and on describing patterns of microbiota variation. However, it remains unclear how environmental variation affects amphibian skin bacterial communities, and whether the overall functional diversity of the amphibian skin microbiota is associated to such variation. We sampled skin microbial communities from one dendrobatoid frog species across an environmental gradient along the Panama Canal, and from three dendrobatoid frog species before and after the onset of the wet season in one site. We found frog skin microbial alpha diversity to be highest in frogs from sites with low soil pH, but no clear effect of the onset of the wet season. However, we found frog skin microbial community structure to be affected by soil pH and the onset of the wet season, which also resulted in a decrease in between-sample variation. Across the sampled frog species, bacterial functional groups changed with the onset of the wet season, with certain bacterial functional groups entirely disappearing and others differing in their relative abundances. In particular, we found the proportion of Bd-inhibitory bacteria to correlate with mean soil pH, and to increase in two of the frog species with the onset of the wet season. Taken together, our results suggest that structure and predicted function of amphibian bacterial skin communities may be influenced by environmental variables such as pH and precipitation, site effects, and host effects.

  15. Mycobacterium marinum infection in Japanese forest green tree frogs (Rhacophorus arboreus).

    Science.gov (United States)

    Haridy, M; Tachikawa, Y; Yoshida, S; Tsuyuguchi, K; Tomita, M; Maeda, S; Wada, T; Ibi, K; Sakai, H; Yanai, T

    2014-01-01

    Four Japanese forest green tree frogs (Rhacophorus arboreus) were presented with emaciation, abdominal distention and ulcerative and nodular cutaneous lesions affecting the brisket, limbs, digits and ventral abdomen. Another three frogs had been found dead in the same tank 1 year previously. Necropsy examination of these seven frogs revealed splenomegaly and hepatomegaly, with multiple tan-yellow nodular foci present in the liver, spleen, heart, lungs, ovaries and kidneys. Microscopically, five frogs had necrosis and surrounding granulomatous inflammation in the liver, spleen, kidneys, lungs, intestine and ovaries, with numerous acid-fast bacilli in the areas of necrosis. Two frogs had granulomatous lesions in the lungs, liver, spleen, heart, coelomic membrane, stomach and intestinal wall. These lesions had no or minimal necrosis and few acid-fast bacilli. Mycobacterium spp. was cultured from three frogs and identified as Mycobacterium marinum by colony growth rate and photochromogenicity and DNA sequencing. This is the first report of M. marinum infection in Japanese forest green tree frogs. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Evolutionary radiation of earless frogs in the Andes: molecular phylogenetics and habitat shifts in high-elevation terrestrial breeding frogs

    Directory of Open Access Journals (Sweden)

    Rudolf von May

    2018-02-01

    Full Text Available The loss of hearing structures and loss of advertisement calls in many terrestrial breeding frogs (Strabomantidae living at high elevations in South America are common and intriguing phenomena. The Andean frog genus Phrynopus Peters, 1873 has undergone an evolutionary radiation in which most species lack the tympanic membrane and tympanic annulus, yet the phylogenetic relationships among species in this group remain largely unknown. Here, we present an expanded molecular phylogeny of Phrynopus that includes 24 nominal species. Our phylogeny includes Phrynopus peruanus, the type species of the genus, and 10 other species for which genetic data were previously unavailable. We found strong support for monophyly of Phrynopus, and that two nominal species—Phrynopus curator and Phrynopus nicoleae—are junior synonyms of Phrynopus tribulosus. Using X-ray computed tomography (CT imaging, we demonstrate that the absence of external hearing structures is associated with complete loss of the auditory skeletal elements (columella in at least one member of the genus. We mapped the tympanum condition on to a species tree to infer whether the loss of hearing structures took place once or multiple times. We also assessed whether tympanum condition, body size, and body shape are associated with the elevational distribution and habitat use. We identified a single evolutionary transition that involved the loss of both the tympanic membrane and tympanic annulus, which in turn is correlated with the absence of advertisement calls. We also identified several species pairs where one species inhabits the Andean grassland and the other montane forest. When accounting for phylogenetic relatedness among species, we detected a significant pattern of increasing body size with increasing elevation. Additionally, species at higher elevations tend to develop shorter limbs, shorter head, and shorter snout than species living at lower elevations. Our findings strongly suggest

  17. Evolutionary and natural history of the turtle frog, Myobatrachus gouldii, a bizarre myobatrachid frog in the southwestern Australian biodiversity hotspot.

    Directory of Open Access Journals (Sweden)

    Samantha Vertucci

    Full Text Available Southwest Australia (SWA is a global biodiversity hotspot and a centre of diversity and endemism for the Australo-Papuan myobatrachid frogs. Myobatrachus gouldii (the turtle frog has a highly derived morphology associated with its forward burrowing behaviour, largely subterranean habit, and unusual mode of reproduction. Its sister genera Metacrinia and Arenophryne have restricted distributions in Western Australia with significant phylogeographic structure, leading to the recent description of a new species in the latter. In contrast, Myobatrachus is distributed widely throughout SWA over multiple climatic zones, but little is known of its population structure, geographic variation in morphology, or reproduction. We generated molecular and morphological data to test for genetic and morphological variation, and to assess whether substrate specialisation in this species may have led to phylogeographic structuring similar to that of other plant and animal taxa in SWA. We assembled sequence data for one mitochondrial and four nuclear DNA loci (3628 base pairs for 42 turtle frogs sampled throughout their range. Likelihood phylogenetic analyses revealed shallow phylogeographic structure in the mtDNA locus (up to 3.3% genetic distance and little variation in three of the four nDNA loci. The mtDNA haplotype network suggests five geographically allopatric groups, with no shared haplotypes between regions. These geographic patterns are congruent with several other SWA species, with genetic groups restricted to major hydrological divisions, the Swan Coastal Plain, and the Darling Scarp. The geographically structured genetic groups showed no evidence of significant morphological differentiation (242 individuals, and there was little sexual size dimorphism, but subtle differences in reproductive traits suggest more opportunistic breeding in lower rainfall zones. Call data were compared to sister genera Metacrinia and Arenophryne and found to be highly

  18. A new species of Andean frog of the genus Bryophryne from southern Peru Anura: Craugastoridae) and its phylogenetic position, with notes on the diversity of the genus.

    Science.gov (United States)

    Chaparro, Juan C; Padial, José M; Gutiérrez, Roberto C; De La Riva, Ignacio

    2015-07-30

    We describe a new species of terrestrial frog of the genus Bryophryne (Anura: Craugastoridae) from the wet puna and elfin forests of the Amazonian versant of the Andes. The new species seems to be restricted to high altitude environments at elevations between 3506-3651 m in the area now protected by Megantoni National Sanctuary and Manu National Park (Distrito de Echarate, Provincia La Convención, Departamento Cusco, Peru). The new species is characterized by lacking vomerine processes of vomers, by having tympanic annulus and tympanic membrane not evident through the skin, smooth dorsal skin with scattered warts, conspicuous dorsolateral, middorsal, and occipital folds, warty flanks, areolate skin on ventral surfaces of the body, and by lacking finger and toe fringes and basal web on feet. In life, specimens have bright and highly variable dorsal coloration that ranges from olive-green to red with variable combinations of red or orange marks (red or orange in the green form and olive-green in the red form). Molecular phylogenetic analyses of mitochondrial and nuclear DNA place the new species within the genus Bryophryne and as sister group of B. cophites. Bryophryne bustamantei, also sequenced for this study, is found as the sister group of the clade formed by B. cophites and the new species. Bryophryne is found as sister group of Psychrophrynella in maximum likelihood analyses and as the sister group of a large clade of holoadenines in parsimony analyses. The genus Bryophryne now contains nine species, all of them distributed along the Cordillera Oriental of the Peruvian Andes, southeast of the Apurimac River valley.

  19. From Amazonia to the Atlantic forest: molecular phylogeny of Phyzelaphryninae frogs reveals unexpected diversity and a striking biogeographic pattern emphasizing conservation challenges.

    Science.gov (United States)

    Fouquet, Antoine; Loebmann, Daniel; Castroviejo-Fisher, Santiago; Padial, José M; Orrico, Victor G D; Lyra, Mariana L; Roberto, Igor Joventino; Kok, Philippe J R; Haddad, Célio F B; Rodrigues, Miguel T

    2012-11-01

    Documenting the Neotropical amphibian diversity has become a major challenge facing the threat of global climate change and the pace of environmental alteration. Recent molecular phylogenetic studies have revealed that the actual number of species in South American tropical forests is largely underestimated, but also that many lineages are millions of years old. The genera Phyzelaphryne (1 sp.) and Adelophryne (6 spp.), which compose the subfamily Phyzelaphryninae, include poorly documented, secretive, and minute frogs with an unusual distribution pattern that encompasses the biotic disjunction between Amazonia and the Atlantic forest. We generated >5.8 kb sequence data from six markers for all seven nominal species of the subfamily as well as for newly discovered populations in order to (1) test the monophyly of Phyzelaphryninae, Adelophryne and Phyzelaphryne, (2) estimate species diversity within the subfamily, and (3) investigate their historical biogeography and diversification. Phylogenetic reconstruction confirmed the monophyly of each group and revealed deep subdivisions within Adelophryne and Phyzelaphryne, with three major clades in Adelophryne located in northern Amazonia, northern Atlantic forest and southern Atlantic forest. Our results suggest that the actual number of species in Phyzelaphryninae is, at least, twice the currently recognized species diversity, with almost every geographically isolated population representing an anciently divergent candidate species. Such results highlight the challenges for conservation, especially in the northern Atlantic forest where it is still degraded at a fast pace. Molecular dating revealed that Phyzelaphryninae originated in Amazonia and dispersed during early Miocene to the Atlantic forest. The two Atlantic forest clades of Adelophryne started to diversify some 7 Ma minimum, while the northern Amazonian Adelophryne diversified much earlier, some 13 Ma minimum. This striking biogeographic pattern coincides with

  20. Effects of host species and life stage on the helminth communities of sympatric northern leopard frogs (Lithobates pipiens) and wood frogs (Lithobates sylvaticus) in the Sheyenne National Grasslands, North Dakota.

    Science.gov (United States)

    Gustafson, Kyle D; Newman, Robert A; Tkach, Vasyl V

    2013-08-01

    We studied helminth communities in sympatric populations of leopard frogs (Lithobates pipiens) and wood frogs (Lithobates sylvaticus) and assessed the effects of host species and life stage on helminth community composition and helminth species richness. We examined 328 amphibians including 218 northern leopard frogs and 110 wood frogs collected between April and August of 2009 and 2010 in the Sheyenne National Grasslands of southeastern North Dakota. Echinostomatid metacercariae were the most common helminths found, with the highest prevalence in metamorphic wood frogs. Host species significantly influenced helminth community composition, and host life stage significantly influenced the component community composition of leopard frogs. In these sympatric populations, leopard frogs were common hosts for adult trematodes whereas wood frogs exhibited a higher prevalence of nematodes with direct life cycles. Metamorphic frogs were commonly infected with echinostomatid metacercariae and other larval trematodes whereas juvenile and adult frogs were most-frequently infected with directly transmitted nematodes and trophically transmitted trematodes. Accordingly, helminth species richness increased with the developmental life stage of the host.

  1. New genus of diminutive microhylid frogs from Papua New Guinea

    Directory of Open Access Journals (Sweden)

    Fred Kraus

    2010-06-01

    Full Text Available A new genus of diminutive (10.1-11.3 mm microhylid frogs is described from New Guinea that is unique in its combination ofonly seven presacral vertebrae, a reduced phalangeal formula that leaves the first fingers and first toes as vestigial nubs, and reduction of the prepollex and prehallux to single elements. Relationships to other genera are unknown, but overall similarity suggests some relationship to Cophixalus, although that genus also differs in some muscle characters and likely remains paraphyletic. The new genus contains two species, which are among the smallest known frogs in the world. Their miniaturization may be related to their inhabiting leaf litter, exploitation of which may for small size. The new genus is currently known only from one mountaintop in the southeasternmost portion of New Guinea and another on a nearby island. This region is part of the East Papuan Composite Terrane and, should this lineage prove endemic to that region, it may suggest that it originated prior to that geological unit’s docking with mainland New Guinea at 23–29 MY.

  2. LOCALIZATION OF PERMEABILITY BARRIERS IN THE FROG SKIN EPITHELIUM

    Science.gov (United States)

    Martinez-Palomo, A.; Erlij, D.; Bracho, H.

    1971-01-01

    Ruthenium red and colloidal lanthanum were used to determine the site of the structural barriers to diffusion within the intercellular spaces of frog skin epithelium. Electron micrographs show that occluding zonules located at the outer border of the stratum corneum and at the outer layer of the stratum granulosum are true tight junctions since they are impermeable to these tracers. Measurement of 140La uptake by the living skin shows that lanthanum moves across the external surface of the skin readily, into and out of a compartment that has a limited capacity and is bounded on its internal side by a barrier impermeable to lanthanum. Examination of these skins with the electron microscope suggests that the compartment is localized between the external membrane of the cells at the outer layer of the s. granulosum and at the outermost surface of the skin. These observations and other findings described in the literature indicate that the site of the external high resistance barrier of the frog skin is localized at the outer border of the s. granulosum. PMID:4329611

  3. The genetic structure of a relict population of wood frogs

    Science.gov (United States)

    Scherer, Rick; Muths, Erin; Noon, Barry; Oyler-McCance, Sara

    2012-01-01

    Habitat fragmentation and the associated reduction in connectivity between habitat patches are commonly cited causes of genetic differentiation and reduced genetic variation in animal populations. We used eight microsatellite markers to investigate genetic structure and levels of genetic diversity in a relict population of wood frogs (Lithobates sylvatica) in Rocky Mountain National Park, Colorado, where recent disturbances have altered hydrologic processes and fragmented amphibian habitat. We also estimated migration rates among subpopulations, tested for a pattern of isolation-by-distance, and looked for evidence of a recent population bottleneck. The results from the clustering algorithm in Program STRUCTURE indicated the population is partitioned into two genetic clusters (subpopulations), and this result was further supported by factorial component analysis. In addition, an estimate of FST (FST = 0.0675, P value \\0.0001) supported the genetic differentiation of the two clusters. Estimates of migration rates among the two subpopulations were low, as were estimates of genetic variability. Conservation of the population of wood frogs may be improved by increasing the spatial distribution of the population and improving gene flow between the subpopulations. Construction or restoration of wetlands in the landscape between the clusters has the potential to address each of these objectives.

  4. [Meiotic chromosomes of the tree frog Smilisca baudinii (Anura: Hylidae)].

    Science.gov (United States)

    Hernández-Guzmán, Javier; Arias-Rodriguez, Lenin; Indy, Jeane Rimber

    2011-03-01

    The Mexican tree frog Smilisca baudinii, is a very common frog in Central America. In spite their importance to keep the ecological equilibrium of the rainforest, its biology and genetics are poorly known. In order to contribute with its biological knowledge, we described the typical meiotic karyotype based in standard cytogenetic protocols to specimens collected in Tabasco, Mexico. The study was centered in the analysis of 131 chromosome spreads at meiotic stage from two adults of the species (one female and one male). The metaphase analysis allowed the establishment of the modal haploid number of 1n = 12 bivalent chromosomes. The chromosomic formulae from the haploid bivalent karyotype was integrated by 12 biarmed chromosomes characterized by twelve pairs of metacentric-submetacentric (msm) chromosomes. The meiotic counting gives the idea that diploid chromosome number is integrated by a complement of 2n = 24 biarmed chromosomes. The presence of sex chromosomes from female and male meiotic spreads was not observed. Current results suggest that S. baudinii chromosome structure is well shared among Hylidae family and "B" chromosomes are particular structures that have very important evolutionary consequences in species diversification.

  5. Superficial and deep blood vessel distribution in the frog telencephalon. Reference to morphological brain asymmetries.

    Science.gov (United States)

    Kemali, M; Sada, E; Fiorino, L

    1990-01-01

    Nine frogs of the species "Rana esculenta" were heart perfused with Microfile Silicone Rubber. The frogs were examined both after dissection (cut with a razor blade) to study the superficial blood vessel pattern, and histologically (the Nissl staining method) to study the distribution of the deep blood capillaries. While the superficial blood vary in pattern, the deep capillaries are distributed symmetrically. This finding does not support a correlation between blood vessel pattern and morphological brain asymmetry, at least in the frog, and thus other explanations must be sought to explain brain asymmetry.

  6. Climatic trends in the Amazonian area of Ecuador: Classical and multifractal analyses

    Science.gov (United States)

    Millán, H.; Kalauzi, A.; Llerena, G.; Sucoshañay, J.; Piedra, D.

    The climate evolution and change in the Amazonian area is very important at least at a continental scale involving Latin America where more than 550 million people live. The objective of the present study was to investigate, from an environmental perspective, the climatic trends in the Amazonian area of continental Ecuador. We performed both classical and multifractal analyses of these trends on four climatic variables (maximum and minimum temperature, evaporation and evaporation/precipitation ratio). Data were collected from Puyo meteorological station, Pastaza Province, Ecuador. Data sets covered 31 years (from January 1974 to September 2005). Each time series consisted of 380 months. Piecewise regression analyses with breaking point showed two regimes with a cutoff ranging from t = 80 months (maximum and minimum temperature) to t = 133 months for the evaporation pattern (determination coefficient ≥ 0.979) while the multifractal analyses showed an increasing complexity within each climatic variable. All the considered climatic variables showed an increase since 1974 to approximately 1985. After that some type of smoother increase was observed.

  7. Seed dispersal by macaws shapes the landscape of an Amazonian ecosystem.

    Science.gov (United States)

    Baños-Villalba, Adrián; Blanco, Guillermo; Díaz-Luque, José A; Dénes, Francisco V; Hiraldo, Fernando; Tella, José L

    2017-08-07

    Seed dispersal is one of the most studied plant-animal mutualisms. It has been proposed that the dispersal of many large-seeded plants from Neotropical forests was primarily conducted by extinct megafauna, and currently by livestock. Parrots can transport large fruits using their beaks, but have been overlooked as seed dispersers. We demonstrate that three macaws (Ara ararauna, A. glaucogularis and A. severus) are the main dispersers of the large-seeded motacú palm Attalea princeps, which is the biomass-dominant tree in the Bolivian Amazonian savannas. Macaws dispersed fruits at high rates (75-100% of fruits) to distant (up to 1200 m) perching trees, where they consumed the pulp and discarded entire seeds, contributing to forest regeneration and connectivity between distant forests islands. The spatial distribution of immature palms was positively associated to the proximity to macaws' perching trees and negatively to the proximity to cattle paths. The disperser role of livestock, presumably a substitute for extinct megafauna, had little effect due to soil compaction, trampling and herbivory. Our results underscore the importance of macaws as legitimate, primary dispersers of large-seeded plants at long distances and, specifically, their key role in shaping the landscape structure and functioning of this Amazonian biome.

  8. Enzymes of energy metabolism in hatchlings of amazonian freshwater turtles (Testudines, Podocnemididae

    Directory of Open Access Journals (Sweden)

    WP. Duncan

    Full Text Available The metabolic profiles of selected tissues were analyzed in hatchlings of the Amazonian freshwater turtles Podocnemis expansa, P. unifilis and P. sextuberculata. Metabolic design in these species was judged based on the key enzymes of energy metabolism, with special emphasis on carbohydrate, lipid, amino acid and ketone body metabolism. All species showed a high glycolytic potential in all sampled tissues. Based on low levels of hexokinase, glycogen may be an important fuel for these species. The high lactate dehydrogenase activity in the liver may play a significant role in carbohydrate catabolism, possibly during diving. Oxidative metabolism in P. sextuberculata appears to be designed for the use of lipids, amino acids and ketone bodies. The maximal activities of 3-hydroxyacyl-CoA dehydrogenase, malate dehydrogenase, glutamine dehydrogenase, alanine aminotransferase and succinyl-CoA keto transferase display high aerobic potential, especially in muscle and liver tissues of this species. Although amino acids and ketone bodies may be important fuels for oxidative metabolism, carbohydrates and lipids are the major fuels used by P. expansa and P. unifilis. Our results are consistent with the food habits and lifestyle of Amazonian freshwater turtles. The metabolic design, based on enzyme activities, suggests that hatchlings of P. unifilis and P. expansa are predominately herbivorous, whereas P. sextuberculata rely on a mixed diet of animal matter and vegetation.

  9. Organic matter in the Neoproterozoic cap carbonate from the Amazonian Craton, Brazil

    Science.gov (United States)

    Sousa Júnior, Gustavo R.; Nogueira, Afonso C. R.; Santos Neto, Eugênio V.; Moura, Candido A. V.; Araújo, Bruno Q.; Reis, Francisco de A. M.

    2016-12-01

    Bitumen found in Neoproterozoic carbonates from the southern Amazonian Craton, Brazil, represents a great challenge for its geochemical characterization (origin, thermal maturity and the degree of preservation) within a context of petroleum system. This organic material occurs in the basal Araras Group, considered as a Neoproterozoic cap carbonate, composed of dolostones (Mirassol d'Oeste Formation) overlaid by limestones and shales (Guia Formation). Geochemical analyses in samples of carbonate with bitumen from two open pits (Terconi and Tangará quarries) have shown low to very low total organic carbon content. Analyses of representative samples of Guia and Mirassol d'Oeste formations allowed us to obtain Gas chromatography (GC) traces and diagnostic biomarkers. n-C14 to n-C37 alkane distribution patterns in all samples suggests a major contribution of marine algae. Mid-chain monomethyl alkanes (C14sbnd C25) identified in both sets of samples were also reported in all mid to late Proterozoic oils and source rocks. However, there are significant differences among terpane distribution between the Mirassol d'Oeste and Tangará da Serra regions. The integration of organic geochemistry data and geological information suggests an indigenous origin for studied bitumen, primarily accumulated as hydrocarbon fluids migrated to carbonate rocks with higher porosity and permeability, and afterwards, altered to bitumen or migrabitumen. Although further investigations are required, this work provides a significant contribution to the knowledge about the remnant of this hypothetical Neoproterozoic petroleum system developed in the Southern Amazonian Craton.

  10. Seasonal variation of serum biochemical values of Amazonian snakes (Boa constrictor constrictor kept in captivity

    Directory of Open Access Journals (Sweden)

    Dennis José da Silva Lima

    2012-11-01

    Full Text Available In northern Brazil, the seasons are not well defined compared to the South and Southeast regions, due to a hot and humid equatorial climate with a rainy season, known as the Amazonian winter, and a period with less rain, known as the Amazonian summer. The goal of this study was to evaluate the biochemical variation of serum from the Amazon Boa constrictor by correlating the values with the seasons of the region. A biochemical analysis of the serum was performed (AST, ALT, LDH, ALP, calcium, uric acid, phosphorus, total protein, albumin and globulin using 31 individuals of Boa constrictor constrictor, which were kept in captivity. It was observed that eight of the ten parameters were higher in the winter compared to the summer (total protein, albumin, globulin, ALT, AST, ALP, LDH and calcium. The ALT, AST and calcium values had statistically significant differences for the summer and winter, while the other parameters appear to be influenced by seasonality. This was the first study of snakes kept in captivity that analyzed the serum chemistry profile of Boa constrictor constrictor from the state of Pará, Brazil.

  11. Hydrological pulse regulating the bacterial heterotrophic metabolism between Amazonian mainstems and floodplain lakes

    Directory of Open Access Journals (Sweden)

    Luciana Oliveira Vidal

    2015-09-01

    Full Text Available We evaluated in situ rates of bacterial carbon processing in Amazonian floodplain lakes and mainstems, during both high and low water phases (p < 0.05. Our results showed that Bacterial Production (BP was lower and more variable than Bacterial Respiration (BR, determined as total respiration. Bacterial Carbon Demand (BCD was mostly accounted by BR and presented the same pattern that BR in both water phases. Bacterial growth efficiency showed a wide range (0.2–23% and low mean value of 3 and 6 %, (in high and low water respectively suggesting that dissolved organic carbon (DOC was mostly allocated to catabolic metabolism. However, BGE was regulated by BP in low water phase. Consequently, changes in BGE showed the same pattern that BP. In addition, the hydrological pulse effects on mainstems and floodplains lakes connectivity were found for BP and BGE in low water. Multiple correlation analyses revealed that indexes of organic matter quality (chlorophyll-a, N stable isotopes and C/N ratios were the strongest seasonal drivers of bacterial carbon metabolism. Our work indicated that: (1 the bacterial metabolism was mostly driven by respiration in Amazonian aquatic ecosystems resulting in low BGE in either high and low water phase; (2 the hydrological pulse regulated

  12. Do soil fertilization and forest canopy foliage affect the growth and photosynthesis of Amazonian saplings?

    Directory of Open Access Journals (Sweden)

    Nilvanda dos Santos Magalhães

    2014-02-01

    Full Text Available Most Amazonian soils are highly weathered and poor in nutrients. Therefore, photosynthesis and plant growth should positively respond to the addition of mineral nutrients. Surprisingly, no study has been carried out in situ in the central Amazon to address this issue for juvenile trees. The objective of this study was to determine how photosynthetic rates and growth of tree saplings respond to the addition of mineral nutrients, to the variation in leaf area index of the forest canopy, and to changes in soil water content associated with rainfall seasonality. We assessed the effect of adding a slow-release fertilizer. We determined plant growth from 2010 to 2012 and gas exchange in the wet and dry season of 2012. Rainfall seasonality led to variations in soil water content, but it did not affect sapling growth or leaf gas exchange parameters. Although soil amendment increased phosphorus content by 60 %, neither plant growth nor the photosynthetic parameters were influenced by the addition of mineral nutrients. However, photosynthetic rates and growth of saplings decreased as the forest canopy became denser. Even when Amazonian soils are poor in nutrients, photosynthesis and sapling growth are more responsive to slight variations in light availability in the forest understory than to the availability of nutrients. Therefore, the response of saplings to future increases in atmospheric [CO2] will not be limited by the availability of mineral nutrients in the soil.

  13. Chemical Composition and Antioxidant, Antinociceptive, and Anti-inflammatory Activities of Four Amazonian Byrsonima Species.

    Science.gov (United States)

    Guilhon-Simplicio, Fernanda; Machado, Tallita Marques; do Nascimento, Leandro Flores; Souza, Rayanne da Silva; Koolen, Hector Henrique Ferreira; da Silva, Felipe Moura Araújo; Acho, Leonard Domingo Rosales; Dos Santos, Adair Roberto Soares; Cos, Paul; Pereira, Maria de Meneses; Lima, Emerson Silva

    2017-11-01

    Species of the Byrsonima genus are widely used in Brazil, especially for the treatment of gastrointestinal disorders. However, species from the Amazonian region are still poorly studied. Thus, we studied the antioxidant, antinociceptive, and anti-inflammatory activities of for Amazonian species, Byrsonima crispa, Byrsonima duckeana, Byrsonima garcibarrigae, and Byrsonima incarnata. Phenolic composition was determined by chemical and chromatographic methods. The aqueous extracts were evaluated in DPPH • , ABTS +• , and superoxide (O 2 •- ) tests, LPS-activated macrophage assay, and formalin test. All species contained a high phenolic and flavonoid content. We identified 15 phenolic compounds, including phenolic acids, hydroxycinnamic acids, flavonoids, and catechins. The extracts showed high antioxidant activity and were more active than quercetin at inhibiting nitric oxide release in the LPS-activated macrophage assay. B. duckeana and B. garcibarrigae showed higher in vivo antinociceptive and anti-inflammatory activities. B. garcibarrigae presented significant effect on the early phase of the formalin test, pointing to an antinociceptive mechanism distinct from traditional anti-inflammatory medicines. In conclusion, the pharmacological potential of these species is closely related to their flavonoid-rich chemical composition, which seems to act through antioxidant mechanisms. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  14. Application of lipases to regiospecific interesterification of exotic oils from an Amazonian area.

    Science.gov (United States)

    Speranza, Paula; Ribeiro, Ana Paula Badan; Macedo, Gabriela Alves

    2016-01-20

    Enzymatic interesterification may favor the development of lipid fractions from Amazonian oils with greater application potential. In this study, the Amazonian buriti oil and murumuru fat were subjected to enzymatic interesterification using two lipases in three different enzyme systems: one with a commercial lipase from Thermomyces lanuginosa, a second with the lipase produced by Rhizopus sp., and a third with a mixture of both lipases. The three enzyme systems were able to catalyze the reaction, but the enzymes showed different specificities. The commercial lipase was specific for unsaturated fatty acids, whereas the Rhizopus sp. lipase was specific for both unsaturated fatty acids and the positions sn -1 and sn -3 of the fatty acid on the triacylglycerol. The mixture of both lipases showed no synergistic effect: the results were intermediate between the two enzymes applied alone. Interesterification reduced the levels of trisaturated and triunsaturated triacylglycerols and increased the levels of diunsaturated-monosaturated and monounsaturated-disaturated triacylglycerols. The thermal melting behavior indicated the formation of a single endothermic region with more homogeneous triacylglycerols. The content of the bioactive β-carotene was preserved after the interesterification reaction with all three-enzyme systems. The interesterified lipids obtained, because of the characteristics of the oils, may be applied to the formulation of cosmetics and pharmaceuticals. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Differential expression of a retrotransposable element, Rex6, in Colossoma macropomum fish from different Amazonian environments

    Science.gov (United States)

    Barbosa, Cassiane Martins; Mareco, Edson Assunção; Silva, Maeli Dal Pai; Martins, Cesar; Alves-Costa, Fernanda Antunes

    2014-01-01

    Transposable elements (TEs) are DNA sequences that have the ability to move and replicate within the genomes. TEs can be classified according to their intermediates of transposition, RNA (retrotransposons) or DNA. In some aquatic organisms, it has been observed that environmental factors such as pH, temperature and pollution may stimulate differential transcription and mobilization of retrotransposons. In light of this information, the present study sought to evaluate the expression of Rex6 TE transcripts in Colossoma macropomum, which is a very commercially exploited fish in Brazil. In order to establish a comparative analysis using real-time PCR, the samples were collected from Amazonian rivers with different physical and chemical characteristics (distinguished by clear water and black water). Quantitative RT-PCR analyses revealed a differential pattern of expression between tissues collected from different types of water (clear and black waters). When it came to the hepatic and muscle tissues sampled, the levels of Rex6 transcripts were significantly different between the two Amazonian water types. These results suggest that environmental conditions operate differently in the regulation of Rex6 transcription in C. macropomum, results which have implications in the reshaping of the genome against environmental variations. PMID:25089227

  16. The extraordinary biology and development of marsupial frogs (Hemiphractidae) in comparison with fish, mammals, birds, amphibians and other animals.

    Science.gov (United States)

    Del Pino, Eugenia M

    2018-01-03

    The study of oogenesis and early development of frogs belonging to the family Hemiphractidae provide important comparison to the aquatic development of other frogs, such as Xenopus laevis, because reproduction on land characterizes the Hemiphractidae. In this review, the multinucleated oogenesis of the marsupial frog Flectonotus pygmaeus (Hemiphractidae) is analyzed and interpreted. In addition, the adaptations associated with the incubation of embryos in the pouch of the female marsupial frog Gastrotheca riobambae (Hemiphractidae) and the embryonic development of this frog are summarized. Moreover, G. riobambae gastrulation is compared with the gastrulation modes of Engystomops randi and Engystomops coloradorum (Leptodactylidae); Ceratophrys stolzmanni (Ceratophryidae); Hyalinobatrachium fleischmanni and Espadarana callistomma (Centrolenidae); Ameerega bilinguis, Dendrobates auratus, Epipedobates anthonyi, Epipedobates machalilla, Epipedobates tricolor, and Hyloxalus vertebralis (Dendrobatidae); Eleutherodactylus coqui (Terrarana: Eleutherodactylidae), and X. laevis (Pipidae). The comparison indicated two modes of frog gastrulation. In X. laevis and in frogs with aquatic reproduction, convergent extension begins during gastrulation. In contrast, convergent extension occurs in the post-gastrula of frogs with terrestrial reproduction. These two modes of gastrulation resemble the transitions toward meroblastic cleavage found in ray-finned fishes (Actinopterygii). In spite of this difference, the genes that guide early development seem to be highly conserved in frogs. I conclude that the shift of convergent extension to the post-gastrula accompanied the diversification of frog egg size and terrestrial reproductive modes. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. Annual cycles of urinary reproductive steroid concentrations in wild and captive endangered Fijian ground frogs (Platymantis vitiana).

    Science.gov (United States)

    Narayan, Edward J; Molinia, Frank C; Christi, Ketan S; Morley, Craig G; Cockrem, John F

    2010-03-01

    Annual cycles of reproductive steroid metabolites were measured in urine collected from free-living and captive tropical endangered Fijian ground frogs (Platymantis vitiana) a terrestrial breeding. Free-living frogs were sampled on Viwa Island, Fiji and captive frogs were maintained in an outdoor enclosure in Suva, Fiji. Urinary estrone, progesterone and testosterone metabolite concentrations increased in male and female frogs after hCG challenges, with clear peaks in steroid concentrations 2 or 3 days after the challenges. There were annual cycles of testosterone metabolites in wild and captive males, and of estrone and progesterone metabolites in wild and captive females. Peaks of steroid concentrations in the wet season corresponded with periods of mating and egg laying in females in December and January. Steroid concentrations declined in January and February when maximum egg sizes in females were also declining. Body weights of wild male and vitellogenic female frogs showed annual cycles. Body weights of non-vitellogenic female frogs varied significantly between months, although there was no clear pattern of annual changes. Body weights of the 3 captive male frogs and 4 captive female frogs were similar to those of the wild frogs. Estrone metabolites were 80% successful in identifying non-vitellogenic females from males. The results suggest that the Fijian ground frog is a seasonal breeder with an annual gonadal cycle, and this species is likely to be photoperiodic. Urinary steroid measurements can provide useful information on reproductive cycles in endangered amphibians. Copyright 2009 Elsevier Inc. All rights reserved.

  18. Heterogeneous effects of market integration on sub-adult body size and nutritional status among the Shuar of Amazonian Ecuador.

    Science.gov (United States)

    Urlacher, Samuel S; Liebert, Melissa A; Josh Snodgrass, J; Blackwell, Aaron D; Cepon-Robins, Tara J; Gildner, Theresa E; Madimenos, Felicia C; Amir, Dorsa; Bribiescas, Richard G; Sugiyama, Lawrence S

    2016-07-01

    Market integration (MI)-increasing production for and consumption from a market-based economy-is drastically altering traditional ways of life and environmental conditions among indigenous Amazonian peoples. The effects of MI on the biology and health of Amazonian children and adolescents, however, remain unclear. This study examines the impact of MI on sub-adult body size and nutritional status at the population, regional and household levels among the Shuar of Amazonian Ecuador. Anthropometric data were collected between 2005-2014 from 2164 Shuar (aged 2-19 years) living in two geographic regions differing in general degree of MI. High-resolution household economic, lifestyle and dietary data were collected from a sub-sample of 631 participants. Analyses were performed to investigate relationships between body size and year of data collection, region and specific aspects of household MI. Results from temporal and regional analyses suggest that MI has a significant and overall positive impact on Shuar body size and nutritional status. However, household-level results exhibit nuanced and heterogeneous specific effects of MI underlying these overarching relationships. This study provides novel insight into the complex socio-ecological pathways linking MI, physical growth and health among the Shuar and other indigenous Amazonian populations.

  19. Heterogeneous effects of market integration on subadult body size and nutritional status among the Shuar of Amazonian Ecuador

    Science.gov (United States)

    Urlacher, Samuel S.; Liebert, Melissa A.; Snodgrass, J. Josh; Blackwell, Aaron D.; Cepon-Robins, Tara J.; Gildner, Theresa E.; Madimenos, Felicia C.; Amir, Dorsa; Bribiescas, Richard G.; Sugiyama, Lawrence S.

    2016-01-01

    Background Market integration (MI) – increasing production for and consumption from a market-based economy – is drastically altering traditional ways of life and environmental conditions among indigenous Amazonian peoples. The effects of MI on the biology and health of Amazonian children and adolescents, however, remain unclear. Aim This study examines the impact of MI on subadult body size and nutritional status at the population, regional, and household levels among the Shuar of Amazonian Ecuador. Subjects and Methods Anthropometric data were collected between 2005 and 2014 from 2,164 Shuar (age 2-19 years) living in two geographic regions differing in general degree of MI. High-resolution household economic, lifestyle, and dietary data were collected from a subsample of 631 participants. Analyses were performed to investigate relationships between body size and year of data collection, region, and specific aspects of household MI. Results Results from temporal and regional analyses suggest that MI has a significant and overall positive impact on Shuar body size and nutritional status. However, household-level results exhibit nuanced and heterogeneous specific effects of MI underlying these overarching relationships. Conclusion This study provides novel insight into the complex socio-ecological pathways linking MI, physical growth, and health among the Shuar and other indigenous Amazonian populations. PMID:27230632

  20. The role of fertile anthropogenic soils in the conservation of native and exotic agrobiodiversity in Amazonian homegardens

    NARCIS (Netherlands)

    Souza, de Nathalia B.; Junqueira, André Braga; Struik, Paul C.; Stomph, Tjeerdjan; Clement, Charles R.

    2017-01-01

    Amazonian dark earths (ADE) are anthropogenic soils mostly created between 500 and 2500 years ago by pre-Columbian populations. ADE are currently used by local people for different agricultural and agroforestry systems. Because of their high fertility they may play an important role in the

  1. BEYOND THE GARDENS: NOTES ON NOMENCLATURE, DISTRIBUTION AND CONSERVATION OF Philodendron melinonii BRONGN. EX REGEL, AN EMBLEMATIC AMAZONIAN AROID

    Directory of Open Access Journals (Sweden)

    Luana S. B. Calazans

    2017-03-01

    Full Text Available Philodendron melinonii is an Amazonian species common in botanical gardens and urban landscaping, however its taxonomy, natural distribution and conservation are barely addressed in the literature. This work presents the nomenclatural history of the species with lectotype designation, a typographical correction and comments on its biogeographic distribution and conservation. Keywords: typification; biogeographic provinces; collection effort; Araceae; Amazonia.

  2. Measurements of soil respiration and simple models dependent on moisture and temperature for an Amazonian southwest tropical forest

    NARCIS (Netherlands)

    Zanchi, F.B.; Rocha, Da H.R.; Freitas, De H.C.; Kruijt, B.; Waterloo, M.J.; Manzi, A.O.

    2009-01-01

    Soil respiration plays a significant role in the carbon cycle of Amazonian tropical forests, although in situ measurements have only been poorly reported and the dependence of soil moisture and soil temperature also weakly understood. This work investigates the temporal variability of soil

  3. Biomass consumption and CO2, CO and main hydrocarbon gas emissions in an Amazonian forest clearing fire

    Science.gov (United States)

    T. G. Soares Neto; J. A. Carvalho; C. A. G. Veras; E. C. Alvarado; R. Gielow; E. N. Lincoln; T. J. Christian; R. J. Yokelson; J. C. Santos

    2009-01-01

    Biomass consumption and CO2, CO and hydrocarbon gas emissions in an Amazonian forest clearing fire are presented and discussed. The experiment was conducted in the arc of deforestation, near the city of Alta Floresta, state of Mato Grosso, Brazil. The average carbon content of dry biomass was 48% and the estimated average moisture content of fresh biomass was 42% on...

  4. Description of the tadpoles of two endemic frogs: the Phu Luang cascade frog Odorrana aureola (Anura: Ranidae) and the Isan big-headed frog Limnonectes isanensis (Anura: Dicroglossidae) from northeastern Thailand.

    Science.gov (United States)

    Ampai, Natee; Rujirawan, Attapol; Arkajag, Jirachai; Mcleod, David S; Aowphol, Anchalee

    2015-07-07

    We describe the external morphology of the tadpoles of two frogs endemic to Thailand: the Phu Luang cascade frog    (Odorrana aureola) and the Isan big-headed frog (Limnonectes isanensis) from the type localities in the Phu Luang Wildlife Sanctuary, Loei Province, northeastern Thailand. Morphological and genetic characters (16S rRNA) were used to identify specimen and match tadpoles to the adults. Detailed descriptions of external morphology and coloration in life are provided for both species. We provide a brief discussion of the ecology of these tadpoles and a comparison to previously published data from tadpoles of closely related taxa. Additionally, we provide evidence for the utility of larval morphology in resolving the taxonomic puzzles presented by cryptic species complexes.

  5. Effects of predatory fish on survival and behavior of larval gopher frogs (Rana capito) and Southern Leopard Frogs (Rana sphenocephala)

    Science.gov (United States)

    Gregoire, D.R.; Gunzburger, M.S.

    2008-01-01

    Southern Leopard Frogs, Rana sphenocephala, are habitat generalists occurring in virtually all freshwater habitats within their geographic range, whereas Gopher Frogs, Rana capito, typically breed in ponds that do not normally contain fish. To evaluate the potential for predation by fish to influence the distribution of these species, we conducted a randomized factorial experiment. We examined the survival rate and behavior of tadpoles when exposed to Warmouth Sunfish, Lepomis gulosus, Banded Sunfish, Enneacanthus obesus, and Eastern Mosquitofish, Gambusia holbrooki. We also conducted a choice experiment to examine the survival rate of the two species of tadpoles when a predator is given a choice of both species simultaneously. Lepomis gulosus consumed the most tadpoles and ate significantly more tadpoles of R. capito than R. sphenocephala. Gambusia holbrooki injured the most tadpoles, especially R. capito. Enneacanthus obesus did not have an effect on behavior or survival of either anuran species. Tadpoles of both anurans increased hiding when in the presence of L. gulosus and G. holbrooki, but a greater proportion of R. capito hid than did R. sphenocephala. Our results suggest that R. capito are more vulnerable to predation by fish than are R. sphenocephala. The introduction of fish may play a role in population declines of certain anurans breeding in normally fish-free wetlands, and even small fish, such as mosquitofish, may have significant negative effects on the tadpoles of R. capito. Copyright 2008 Society for the Study or Amphibians and Reptiles.

  6. Phylogenetic relationships of Amazonian anole lizards (Dactyloa): taxonomic implications, new insights about phenotypic evolution and the timing of diversification.

    Science.gov (United States)

    Prates, Ivan; Rodrigues, Miguel Trefaut; Melo-Sampaio, Paulo Roberto; Carnaval, Ana Carolina

    2015-01-01

    The ecology and evolution of Caribbean anoles are well described, yet little is known about mainland anole species. Lack of phylogenetic information limits our knowledge about species boundaries, morphological evolution, and the biogeography of anoles in South America. To help fill this gap, we provide an updated molecular phylogeny of the Dactyloa (Dactyloidae), with emphasis on the punctata species group. By sampling understudied Amazonian taxa, we (i) assess the phylogenetic placement of the 'odd anole', D. dissimilis; (ii) infer the relationships of the proboscis-bearing D. phyllorhina, testing the hypothesis of independent nasal appendage evolution within the anole radiation; and (iii) examine genetic and dewlap color variation in D. punctata and D. philopunctata. Combining multiple nuclear loci with a review of the fossil record, we also (iv) estimate divergence times within the pleurodont iguanian clade of lizards, including Amazonian representatives of Dactyloa and Norops (Dactyloidae) and of Polychrus (Polychrotidae). We recover the five Dactyloa clades previously referred to as the aequatorialis, heteroderma, latifrons, punctata and roquet species groups, as well as a sixth clade composed of D. dissimilis and the non-Amazonian D. neblinina and D. calimae. We find D. phyllorhina to be nested within the punctata group, suggesting independent evolution of the anole proboscis. We consistently recover D. philopunctata nested within D. punctata, and report limited genetic divergence between distinct dewlap phenotypes. The most recent common ancestor of Dactyloa, Anolis and Norops dates back to the Eocene. Most Amazonian taxa within both Dactyloa and Norops diverged in the Miocene, but some diversification events were as old as the late Eocene and late Oligocene. Amazonian Polychrus diverged in the Pliocene. Our findings have broad implications for anole biogeography, disputing recent suggestions that modern dactyloid genera were present in the Caribbean region

  7. Further Development and Validation of the Frog Embryo Teratogenesis Assay - Xenopus (FETAX). Phase III

    National Research Council Canada - National Science Library

    Bantle, John

    1996-01-01

    This interlaboratory study of the Frog Embryo Teratogenesis Assay (FETAX) was undertaken in order to assess the repeatability and reliability of data collected under the guide published by the American Society for Testing and Materials...

  8. EVIDENCE FOR PHYLOGENETICALLY DISTINCT LEOPARD FROGS (RANA ONCA) FROM THE BORDER REGION OF NEVADA, UTAH, ARIZONA

    Science.gov (United States)

    Remnant populations of leopard frogs exist within the Virgin River drainage and adjacent portions of the Colorado River (Black Canyon) in northwestern Arizona and southern Nevada. These populations either represent the reportedly extinct taxa Rana onca or northern, disjunct R...

  9. Effects of oxymorphazone in frogs: long lasting antinociception in vivo, and apparently irreversible binding in vitro

    International Nuclear Information System (INIS)

    Benyhe, S.; Hoffman, G.; Varga, E.; Hosztafi, S.; Toth, G.; Borsodi, A.; Wollemann, M.

    1989-01-01

    Oxymorphazone was found to be a relatively weak antinociceptive drug in intact frog (Rana esculenta) when acetic acid was used as pain stimulus. Frogs remained analgesic for at least 48 hrs following oxymorphazone administration. The ligand increased the latency of wiping reflex in spinal frogs too. There effects were blocked by naloxone. In equilibrium binding studies ( 3 H)oxymorphazone had high affinity to the opioid receptors of frog brain and spinal cord as well. Kinetic experiments show that only 25% of the bound ( 3 H)oxymorphazone is readily dissociable. Preincubation of the membranes with labeled oxymorphazone results in a washing resistant inhibition of the opioid binding sites. At least 70% of the ( 3 H)oxymorphazone specific binding is apparently irreversible after reaction at 5 nM ligand concentration, and this can be enhanced by a higher concentration of tritiated ligand

  10. Levels of batrachotoxin and lack of sensitivity to its action in poison-dart frogs (Phyllobates).

    Science.gov (United States)

    Daly, J W; Myers, C W; Warnick, J E; Albuquerque, E X

    1980-06-20

    Batrachotoxin is present in remarkably high amounts in the skin of Phyllobates terribilis. Levels of batrachotoxin tend to be reduced when P. terribilis is maintained in captivity, but even after being confined for up to 6 years, these frogs were still at least five times more toxic than other Phyllobates species used by natives for poisoning blowgun darts. Batrachotoxin was not detectable in F1 progeny reared to maturity in captivity. Nerve and muscle preparations from wild-caught frogs and from the nontoxic F1 frogs were both insensitive to batrachotoxin. The regulatory site controlling sodium-channel activation and permeability appears to have been minimally altered to prevent interaction with batrachotoxin, but is still sensitive to other sodium conductance activators (veratridine, grayanotoxin) to which the frogs arenot exposed naturally.

  11. Effects of oxymorphazone in frogs: long lasting antinociception in vivo, and apparently irreversible binding in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Benyhe, S.; Hoffman, G.; Varga, E.; Hosztafi, S.; Toth, G.; Borsodi, A.; Wollemann, M.

    1989-01-01

    Oxymorphazone was found to be a relatively weak antinociceptive drug in intact frog (Rana esculenta) when acetic acid was used as pain stimulus. Frogs remained analgesic for at least 48 hrs following oxymorphazone administration. The ligand increased the latency of wiping reflex in spinal frogs too. There effects were blocked by naloxone. In equilibrium binding studies (/sup 3/H)oxymorphazone had high affinity to the opioid receptors of frog brain and spinal cord as well. Kinetic experiments show that only 25% of the bound (/sup 3/H)oxymorphazone is readily dissociable. Preincubation of the membranes with labeled oxymorphazone results in a washing resistant inhibition of the opioid binding sites. At least 70% of the (/sup 3/H)oxymorphazone specific binding is apparently irreversible after reaction at 5 nM ligand concentration, and this can be enhanced by a higher concentration of tritiated ligand.

  12. Angiotensin II suppresses water absorption through the ventral skin of Japanese tree-frogs in vitro.

    Science.gov (United States)

    Tokuda, C; Kimura, K; Kamishima, Y

    1995-04-01

    We previously described two different water absorption systems in the ventral skin of the Japanese tree-frog, Hyla arborea japonica: i.e., a rapid enhanced flow, which is observed in dehydrated tree-frogs or those stimulated by adrenaline beta-agonists or vasotocin, and a slow basal flow, which is observed in normally hydrated frogs during the non-breeding season. The rapid flow is completely blocked by ouabain, which has no effects on the slow basal flow. In the present experiment, we show that the vaso-constrictive hormone angiotensin II completely inhibits basal water absorption, but has no effect on rapid water absorption. These results confirm our previous finding that the two water absorption systems in the ventral skin of the Japanese tree-frog are independent of each other.

  13. The Developmental Effects Of A Municipal Wastewater Effluent On The Northern Leopard Frog, Rana pipiens

    Science.gov (United States)

    Wastewater effluents are complex mixtures containing a variety of anthropogenic compounds, many of which are known endocrine disruptors. In order to characterize the development and behavorial effects of such a complex mixture, northern leopard frogs, Rana pipiens, were e...

  14. Stormwater wetlands can function as ecological traps for urban frogs.

    Science.gov (United States)

    Sievers, Michael; Parris, Kirsten M; Swearer, Stephen E; Hale, Robin

    2018-03-01

    Around cities, natural wetlands are rapidly being destroyed and replaced with wetlands constructed to treat stormwater. Although the intended purpose of these wetlands is to manage urban stormwater, they are inhabited by wildlife that might be exposed to contaminants. These effects will be exacerbated if animals are unable to differentiate between stormwater treatment wetlands of varying quality and some function as 'ecological traps' (i.e. habitats that animals prefer despite fitness being lower than in other habitats). To examine if urban stormwater wetlands can be ecological traps for frogs, we tested if survival, metamorphosis-related measures and predator avoidance behaviours of frogs differed within mesocosms that simulated stormwater wetlands with different contaminant levels, and paired this with a natural oviposition experiment to assess breeding-site preferences. We provide the first empirical evidence that these wetlands can function as ecological traps for frogs. Tadpoles had lower survival and were less responsive to predator olfactory cues when raised in more polluted stormwater wetlands, but also reached metamorphosis earlier and at a larger size. A greater size at metamorphosis was likely a result of increased per capita food availability due to higher mortality combined with eutrophication, although other compensatory effects such as selective-mortality removing smaller individuals from low-quality mesocosms may also explain these results. Breeding adults laid comparable numbers of eggs across wetlands with high and low contaminant levels, indicating no avoidance of the former. Since stormwater treatment wetlands are often the only available aquatic habitat in urban landscapes we need to better understand how they perform as habitats to guide management decisions that mitigate their potential ecological costs. This may include improving wetland quality so that fitness is no longer compromised, preventing colonisation by animals, altering the cues

  15. 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

  16. Nuclear Abnormalities in Erythrocytes of Frogs From Wetlands and Croplands of Western Ghats Indicate Environmental Contaminations

    OpenAIRE

    Raghunath, Shreyas; Veerabhadrappa, Chethankumar Masaruru; Krishnamurthy, Sannanegunda Venkatarama Bhatta

    2017-01-01

    Anuran amphibians are the biological models to assess the influence of environmental contamination. We conducted nuclear abnormality assessment and micronuclei test in erythrocytes of frogs to identify an early influence of environmental contaminations. In Western Ghats of India, farmers use different agrochemicals and obviously, the amphibian habitat is contaminated with combinations of many residues. Many frog species use these agro-ecosystem for breeding and to complete early life stage. I...

  17. Interference of a short-chain phospholipid with ion transport pathways in frog skin

    DEFF Research Database (Denmark)

    Unmack, M A; Frederiksen, O; Willumsen, N J

    1997-01-01

    The effects of mucosal application of the short-chain phospholipid didecanoyl-L-alpha-phosphatidylcholine (DDPC; with two saturated 10-carbon acyl chains) on active Na+ transport and transepithelial conductance (G) in the frog skin (Rana temporaria) were investigated. Active Na+ transport...... of the frog skin epithelium and opens a paracellular tight junction pathway. Both effects may be caused by incorporation of DDPC in the apical cell membrane....

  18. Pecular Features of Hematopoiesis in the Liver of Mature and Immature Green Frogs (Pelophylax Esculentus Complex

    Directory of Open Access Journals (Sweden)

    Akulenko N. M.

    2016-12-01

    Full Text Available The article describes characteristic features of the hematopoiesis in mature and immature green frogs (Pelophylax esculentus complex. Quantitative differences in liver myelograms were insignificant. However, in a sample of mature animals numerous significant correlations between the number of pigment inclusions in the liver and indicators of erythropoiesis and myelopoiesis were observed. Those correlations were absent in the immature frogs. We concluded that aft er the frogs’ breeding a lack of plastic resources, in particular, hemosiderin remains up to the hibernation.

  19. Sexual differences in prevalence of a new species of trypanosome infecting túngara frogs

    Directory of Open Access Journals (Sweden)

    Ximena E. Bernal

    2016-04-01

    Full Text Available Trypanosomes are a diverse group of protozoan parasites of vertebrates transmitted by a variety of hematophagous invertebrate vectors. Anuran trypanosomes and their vectors have received relatively little attention even though these parasites have been reported from frog and toad species worldwide. Blood samples collected from túngara frogs (Engystomops pustulosus, a Neotropical anuran species heavily preyed upon by eavesdropping frog-biting midges (Corethrella spp., were examined for trypanosomes. Our results revealed sexual differences in trypanosome prevalence with female frogs being rarely infected (<1%. This finding suggests this protozoan parasite may be transmitted by frog-biting midges that find their host using the mating calls produced by male frogs. Following previous anuran trypanosome studies, we examined 18S ribosomal RNA gene to characterize and establish the phylogenetic relationship of the trypanosome species found in túngara frogs. A new species of giant trypanosome, Trypanosoma tungarae n. sp., is described in this study. Overall the morphometric data revealed that the trypomastigotes of T. tungarae n. sp. are similar to other giant trypanosomes such as Trypanosoma rotatorium and Trypanosoma ranarum. Despite its slender and long cell shape, however, 18S rRNA gene sequences revealed that T. tungarae n. sp. is sister to the rounded-bodied giant trypanosome, Trypanosoma chattoni. Therefore, morphological convergence explains similar morphology among members of two non-closely related groups of trypanosomes infecting frogs. The results from this study underscore the value of coupling morphological identification with molecular characterization of anuran trypanosomes.

  20. Distribution and postbreeding environmental relationships of Northern leopard frogs (Rana [Lithobates] pipiens) in Washington

    Science.gov (United States)

    Germaine, S.S.; Hays, D.W.

    2009-01-01

    Northern leopard frogs (Rana [Lithobates] pipiens) are considered sensitive, threatened, or endangered in all western states and western Canadian provinces. Historically present in eastern Washington in 6 major river drainages, leopard frogs are now only known to occur at 2 localized areas in the Crab Creek drainage in Grant County. During the summers of 2002-2005, we surveyed both areas to document extent of leopard frog distributions and to describe habitat and vertebrate community characteristics associated with leopard frog site occupancy. At Gloyd Seeps, 2 juvenile leopard frogs were observed in a total of 8.2 person-days of searching along a 5-km stream reach. At Potholes Reservoir, we surveyed 243 wetland sites in 7 management units known to have been occupied by leopard frogs during the 1980s. We confirmed leopard frog presence at only 87 sites (36%) in 4 management units. Site occupancy models for individual ponds indicated that, compared to unoccupied sites, occupied sites had slightly greater pond depths, less tall emergent vegetation, more herbaceous vegetative cover, and fewer neighboring ponds containing nonnative predatory fish. Models developed at the 1-km2 scale indicated that occupied areas had greater average midsummer pond depths, fewer ponds occupied by bullfrogs (Rana [Lithobates] catesbeiana) and carp (Cyprinus carpio), and more herbaceous vegetation surrounding ponds. The Gloyd Seeps population now appears defunct, and the Potholes Reservoir population is in sharp decline. Unless management actions are taken to reduce nonnative fish and bullfrogs and to enhance wetland vegetation, leopard frogs may soon be extirpated from both sites and possibly, therefore, from Washington.

  1. Evidence for an enantioselective pumiliotoxin 7-hydroxylase in dendrobatid poison frogs of the genus Dendrobates

    OpenAIRE

    Daly, John W.; Garraffo, H. Martin; Spande, Thomas F.; Clark, Valerie C.; Ma, Jingyuan; Ziffer, Herman; Cover, John F.

    2003-01-01

    Dendrobatid poison frogs readily accumulate alkaloids from diet into skin, where such compounds serve as a chemical defense against predators. Arthropods seem to be the source of decahydroquinolines (DHQs), several izidines, coccinellines, spiropyrrolizidines, pumiliotoxins (PTXs), and allopumiliotoxins (aPTXs). A DHQ iso-223F, and PTX (+)-251D were fed to poison frogs of the dendrobatid genera Dendrobates, Epipedobates, and Phyllobates. The two alkaloids were accumulated in skin unchanged ex...

  2. Glycogen accumulation in normal and irradiated minced muscle autografts on frog gastrocnemius

    International Nuclear Information System (INIS)

    Malhotra, R.K.; Kaul, R.; Malhotra, N.

    1989-01-01

    Alterations induced in glycogen content and phosphorylase activity have been studied in normal and irradiated minced muscle autografts on frog gastrocnemius at days 1, 3, 5, 7, 10, 15 and 30 postgrafting. The changes observed in the glycogen content and phosphorylase activity conform to the degeneration and regeneration phases of muscle repair. An attempt has been made to explain the altered glycogen utilizing capacities of the frog skeletal muscle during its repair and regeneration. (author)

  3. Reproduction and hybrid load in all-hybrid populations of Rana esculenta water frogs in Denmark

    DEFF Research Database (Denmark)

    Christiansen, Ditte Guldager; Fog, Kåre; Pedersen, Bo Vest

    2005-01-01

    All-hybrid populations of the water frog, Rana esculenta, are exceptional in consisting of independently and to some extent sexually reproducing interspecific hybrids. In most of its range R. esculenta reproduces hemiclonally with one of the parental species, R. lessonae or R. ridibunda, but viable...... gametogenesis and mating between frogs with incompatible gametes induce a significant hybrid load in all-hybrid populations of R. esculenta, and we discuss compensating advantages and potential evolutionary trajectories to reduce this hybrid load....

  4. Effects of X-irradiation on some aspects of protein metabolism in the frog, Rana hexadactyla

    International Nuclear Information System (INIS)

    Rajarami Reddy, G.; Sasira Babu, K.

    1980-01-01

    Changes in the level of total proteins and protease in brain, muscle and liver tissues of normal and X-irradiated frogs were determined. Low doses of radiation produced an increment in protein level while high doses produced decrement. However, protease activity at all doses exhibited an elevatory trend. Exposure of frogs to lethal doses resulted in increased protease activity and decreased protein content during post-irradiation periods. The results are discussed on the basis of protein destruction and lysosomal damage. (auth.)

  5. Reel Royal Diversity? The Glass Ceiling in Disney’s Mulan and Princess and the Frog

    OpenAIRE

    Lauren Dundes; Madeline Streiff

    2016-01-01

    Both in Mulan and Princess and the Frog, Disney eschews a traditional fairytale ending involving palatial opulence by substituting an alternative narrative for women of color. Mulan disguises herself as a male soldier in order to serve in her father’s place. After sharing victory with male companions, she willingly returns home to domesticity and the confines imposed by her gender. Tiana spends two thirds of the movie as a frog, substantially limiting her on-screen time as an African American...

  6. The Potential of Frog Skin-Derived Peptides for Development into Therapeutically-Valuable Immunomodulatory Agents

    OpenAIRE

    Jelena M. Pantic; Ivan P. Jovanovic; Gordana D. Radosavljevic; Nebojsa N. Arsenijevic; J. Michael Conlon; Miodrag L. Lukic

    2017-01-01

    The aim of this article is to review the immunoregulatory actions of frog skin-derived peptides in order to assess their potential as candidates for immunomodulatory or anti-inflammatory therapy. Frog skin peptides with demonstrable immunomodulatory properties have been isolated from skin secretions of a range of species belonging to the families Alytidae, Ascaphidae, Discoglossidae, Leptodactylidae, Pipidae and Ranidae. Their effects upon production of inflammatory and immunoregulatory cytok...

  7. Helminth parasites of the lemon-yellow tree frog, Hyla savignyi (Hylidae), from Turkey

    OpenAIRE

    YILDIRIMHAN, Hikmet Sami; SÜMER, Nurhan; İNCEDOĞAN, Sezen; BURSEY, Charles Robert

    2012-01-01

    Forty lemon-yellow tree frogs, Hyla savignyi, collected from Kırıkhan, Turkey (25 in April 2009, 15 in April 2010), were examined for helminths, and 21 frogs were found to be infected. One species of Monogenea (Polystoma integerrimum), 3 species of Digenea (Diplodiscus subclavatus, Halipegus kessleri, and Pleurogenoides medians), 1 species of Cestoda (Nematotaenia dispar), and 2 species of Nematoda (Aplectana brumpti and Cosmocerca commutata) were found. Hyla savignyi represents a new host ...

  8. 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.

    2009-01-01

    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). 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

  9. California red-legged frog (Rana draytonii) movement and habitat use: Implications for conservation

    Science.gov (United States)

    Fellers, G.M.; Kleeman, P.M.

    2007-01-01

    Nonbreeding habitats are critically important for Rana draytonii, especially for individuals that breed in temporary bodies of water. We radiotracked 123 frogs to evaluate seasonal habitat use. Individual frogs were continuously tracked for up to 16 months. Some individuals remained at breeding ponds all year, but 66% of female and 25% of male frogs moved to nonbreeding areas, even when the breeding site retained water. Frogs at our main study site moved 150 m (median), roughly the distance to the nearest suitable nonbreeding area. The greatest straight-line distance traveled was 1.4 km, although the presumed distance traveled was 2.8 km. Females were more likely than males to move from permanent ponds (38% of females, 16% of males), but among dispersing frogs, males and females did not differ in distance moved. Some frogs left breeding sites shortly after oviposition (median = 12 days for females, 42.5 days for males), but many individuals remained until the site was nearly dry. Fog provided moisture for dispersal or migration throughout the summer. Our data demonstrate that maintaining populations of pond-breeding amphibians requires that all essential habitat components be protected; these include (1) breeding habitat, (2) nonbreeding habitat, and (3) migration corridors. In addition, a buffer is needed around all three areas to ensure that outside activities do not degrade any of the three habitat components. Copyright 2007 Society for the Study of Amphibians and Reptiles.

  10. The evolution of development: two portraits of skull ossification in pipoid frogs.

    Science.gov (United States)

    Yeh, Jennifer

    2002-12-01

    Development creates morphology, and the study of developmental processes has repeatedly shed light on patterns of morphological evolution. However, development itself evolves as well, often concomitantly with changes in life history or in morphology. In this paper, two approaches are used to examine the evolution of skull development in pipoid frogs. Pipoids have highly unusual morphologies and life histories compared to other frogs, and their development also proves to be remarkable. First, a phylogenetic examination of skull bone ossification sequences reveals that jaw ossification occurs significantly earlier in pipoids than in other frogs; this represents a reversal to the primitive vertebrate condition. Early jaw ossification in pipoids is hypothesized to result from the absence of certain larval specializations possessed by other frogs, combined with unusual larval feeding behaviors. Second, thin-plate spline morphometric studies of ontogenetic shape change reveal important differences between pipoid skull development and that of other frogs. In the course of frog evolution, there has been a shift away from salamander-like patterns of ontogenetic shape change. The pipoids represent the culmination of this trend, and their morphologies are highly derived in numerous respects. This study represents the first detailed examination of the evolution of skull development in a diverse vertebrate clade within a phylogenetic framework. It is also the first study to examine ossification sequences across vertebrates, and the first to use thin-plate spline morphometrics to quantitatively describe ontogenetic trajectories.

  11. Impact of Dams on Riparian Frog Communities in the Southern Western Ghats, India

    Directory of Open Access Journals (Sweden)

    Rohit Naniwadekar

    2014-08-01

    Full Text Available The Western Ghats is a global biodiversity hotspot and home to diverse and unique assemblages of amphibians. Several rivers originate from these mountains and hydropower is being tapped from them. The impacts of hydrological regulation of riparian ecosystems to wildlife and its habitat are poorly documented, and in particular the fate of frog populations is unknown. We examined the effects of dams on riparian frog communities in the Thamirabarani catchment in southern Western Ghats. We used nocturnal visual encounter surveys constrained for time, to document the species richness of frogs below and above the dam, and also at control sites in the same catchment. While we did not find differences in species richness below and above the dams, the frog community composition was significantly altered as a likely consequence of altered flow regime. The frog species compositions in control sites were similar to above-dam sites. Below-dam sites had a distinctly different species composition. Select endemic frog species appeared to be adversely impacted due to the dams. Below-dam sites had a greater proportion of generalist and widely distributed species. Dams in the Western Ghats appeared to adversely impact population of endemic species, particularly those belonging to the genus Nyctibatrachus that shows specialization for intact streams.

  12. Formicine ants: An arthropod source for the pumiliotoxin alkaloids of dendrobatid poison frogs.

    Science.gov (United States)

    Saporito, Ralph A; Garraffo, H Martin; Donnelly, Maureen A; Edwards, Adam L; Longino, John T; Daly, John W

    2004-05-25

    A remarkable diversity of bioactive lipophilic alkaloids is present in the skin of poison frogs and toads worldwide. Originally discovered in neotropical dendrobatid frogs, these alkaloids are now known from mantellid frogs of Madagascar, certain myobatrachid frogs of Australia, and certain bufonid toads of South America. Presumably serving as a passive chemical defense, these alkaloids appear to be sequestered from a variety of alkaloid-containing arthropods. The pumiliotoxins represent a major, widespread, group of alkaloids that are found in virtually all anurans that are chemically defended by the presence of lipophilic alkaloids. Identifying an arthropod source for these alkaloids has been a considerable challenge for chemical ecologists. However, an extensive collection of neotropical forest arthropods has now revealed a putative arthropod source of the pumiliotoxins. Here we report on the presence of pumiliotoxins in formicine ants of the genera Brachymyrmex and Paratrechina, as well as the presence of these ants in the stomach contents of the microsympatric pumiliotoxin-containing dendrobatid frog, Dendrobates pumilio. These pumiliotoxins are major alkaloids in D. pumilio, and Brachymyrmex and Paratrechina ants now represent the only known dietary sources of these toxic alkaloids. These findings further support the significance of ant-specialization and alkaloid sequestration in the evolution of bright warning coloration in poison frogs and toads.

  13. Aberrant femoral torsion presenting with frog-leg squatting mimicking gluteal muscle contracture.

    Science.gov (United States)

    Chiang, Chia-Ling; Tsai, Meng-Yuan; Chang, Wei-Ning; Chen, Clement Kuen-Huang

    2012-04-01

    Patients with frog-leg squatting have restricted internal rotation and adduction of the affected hips during sitting or squatting. In the surgical literature, the cause generally has been presumed to arise from and be pathognomonic for gluteal muscle contracture. However, we have encountered patients with frog-leg squatting but without gluteal muscle contracture. We therefore raised the following questions: What are the imaging features of patients with frog-leg squatting? Do conditions other than gluteal muscle contracture manifest frog-leg squatting? We retrospectively reviewed the MR images of 67 patients presenting with frog-leg squatting from April 1998 to July 2010. There were four females and 63 males; their mean age was 22.2 years (range, 4-50 years). During MRI readout, we observed aberrant axes of some femoral necks and obtained additional CT to measure femoral torsion angles in 59 of the 67 patients. MR images of 27 (40%) patients had signs of gluteal muscle contracture. Twenty-two (33%) patients (40 femora) had aberrant femoral torsion, including diminished anteversion (range, 6°-0°; average, 3.9°) in 11 femora of eight patients and femoral retroversion (range, muscle contracture or aberrant femoral torsion. The observation of aberrant femoral torsion was not anticipated before imaging studies. In addition to gluteal muscle contracture, aberrant femoral torsion can be a cause of frog-leg squatting. Level II, diagnostic study. See the guidelines for Authors for a complete description of levels of evidence.

  14. Placement of intracoelomic radio transmitters and silicone passive sampling devices in northern leopard frogs (Lithobates pipiens)

    Science.gov (United States)

    Yaw, Taylor; Swanson, Jennifer E; Pierce, Clay; Muths, Erin L.; Smalling, Kelly; Vandever, Mark; Zaffarano, Bianca Anne

    2017-01-01

    Historically, wetland toxin exposure studies have relied on single time point samples from stationary sampling devices. Development of passive sampling devices (PSDs) that can be attached to individual animals within wetland habitats has greatly improved in recent years, presenting an innovative sampling technology that can potentially yield individual-specific, quantifiable data about chemical exposure. In this study, silicone based PSDs were attached to the ventral skin of 20 northern leopard frogs (Lithobates pipiens) with polypropylene sutures after radio transmitters had been surgically implanted into the coleomic cavity. After a recovery period frogs were released back into the wetland habitat where they were acquired. The animals were located daily using radio telemetry to assess how long PSDs would remain attached in the frogs' natural habitat. After one week, PSDs remained on 18 of the original 20 frogs. At 2 weeks 17 frogs were recovered and no PSDs remained attached. Although valuable data can be obtained over a short time period, more research will be necessary to demonstrate effectiveness of externally attaching silicone PSDs to northern leopard frogs for time periods longer than 1-2 weeks.

  15. Effects of acute exposure to magnetic field on ionic composition of frog sciatic nerve

    International Nuclear Information System (INIS)

    Salem, A.; Hafedh, A.; Mohsen, S.

    2004-01-01

    Objective: To evaluate the possible interaction between magnetic field and cadmium on ionic composition of frog sciatic nerve. Design: The combined effect of magnetic field and cadmium (1.5mg/kg; in lymphatic sac) were studied in frog sciatic nerves (Rana Esculenta). Sciatic nerve samples were extracted, weighed and mixed in bidistilled water in order to analyze by inductively coupled plasma (ICP) ionic composition. Setting: Frogs (Rana Esculenta) were reared in swimming-pool (Faculte des Sciences de Bizerte, Tunisia). Frogs were cared for under the Tunisian Code of Practice for the Care and Use of Animals for Scientific purpose and the Experimental Protocols were approved by the Ethics Committee. Subjects: Treated and control groups (n=6) weighing 50-100g at the time of experiments were housed in the same condition three weeks before the beginning of the experiments. Results: Acute exposure to magnetic field increased significantly the calcium (+298%, p<0.05) and iron (+50%, p<0.05) contents of frog sciatic nerve, whereas magnesium and copper contents remained unchanged. The association between magnetic field and cadmium, induced marked increase of calcium (+360%, p<0.05), whereas magnesium content remained stable. Conclusions: Magnetic field exposure alters the ionic composition in the frog sciatic nerve, especially calcium and iron. Magnetic field magnifies the effect of cadmium on calcium homeostasis. (author)

  16. Gas chromatographic and electron spin resonance investigations of gamma-irradiated frog legs

    International Nuclear Information System (INIS)

    Morehouse, K.M.; Ku, Yuoh; Albrecht, H.L.; Yang, G.C.

    1991-01-01

    Several very sensitive techniques to measure radiation-induced products in frog legs were investigated. Presented here are results from the use of electron spin resonance (ESR) spectroscopy and capillary gas chromatography (GC) to measure radiolysis products in γ-irradiated frog legs. When bone is irradiated, a characteristic ESR signal develops and is easily measured. The intensity of the ESR signal is dose-dependent and stable for several months at room temperature. When triglycerides or fatty acids are irradiated, some of the major stable products formed are hydrocarbons with one less carbon than the precursor fatty acids. These hydrocarbons are formed as the result of the loss of CO 2 during various free radical reactions. A capillary GC procedure was developed to monitor the formation of these hydrocarbons in γ-irradiated frog legs. Since frog legs contain large amounts of palmitic, stearic, oleic, and linoleic acids, the formation of the hydrocarbons (pentadecane, heptadecane, 8-heptadecene, and 6,9-heptadecadiene, respectively) from the decarboxylation of these fatty acids was monitored. The yields of these hydrocarbons were found to be linear with applied dose. A sample from a lot of imported frog legs that were believed to have been treated with ionizing radiation was also analyzed. The ESR technique, in conjunction with the GC data on the hydrocarbons, appears to be a useful approach for identifying and monitoring frog legs that have been treated with ionizing radiation. (author)

  17. The island rule in the Brazilian frog Phyllodytes luteolus (Anura: Hylidae: incipient gigantism?

    Directory of Open Access Journals (Sweden)

    Marcio Mageski

    2015-10-01

    Full Text Available ABSTRACT The island rule suggests that, when mainland animals are isolated on islands, large animals tend to become smaller, while small animals tend to become larger. A small frog in eastern Brazil, Phyllodytes luteolus (Wied-Neuwied, 1824, is widely distributed in association with bromeliads. At the end of the last glaciation, parts of the mainland became islands due to rising sea levels, thereby isolating frog populations on these islands. If the island rule holds, we predicted that frogs on islands would tend to be larger than frogs on the mainland. We compared sizes (weight and length of 30 randomly selected male frogs from the mainland with 30 from an island in the state of Espírito Santo, Brazil. We also sampled population density on the island and mainland because concurrent with changing sizes, depending on the causal relationship, density may also change. As predicted, island frogs tended to be larger (both in snout-vent length and weight and were much more abundant. While not specifically addressed in this study, the absence of predators and interspecific competitors may explain both of these trends.

  18. Influence of drainage status on soil and water chemistry, litter decomposition and soil respiration in central Amazonian forests on sandy soils

    NARCIS (Netherlands)

    Berton Zanchi, F.; Waterloo, M.J.; Dolman, A.J.; Groenendijk, M.; Kruijt, B.

    2011-01-01

    Central Amazonian rainforest landscape supports a mosaic of tall terra firme rainforest and ecotone campinarana, riparian and campina forests, reflecting topography-induced variations in soil, nutrient and drainage conditions. Spatial and temporal variations in litter decomposition, soil and

  19. Origin of invasive Florida frogs traced to Cuba

    Science.gov (United States)

    Heinicke, Matthew P.; Diaz, Luis M.; Hedges, S. Blair

    2011-01-01

    Two of the earliest examples of successful invasive amphibians are the greenhouse frog (Eleutherodactylus planirostris) and the Cuban treefrog (Osteopilus septentrionalis) in Florida. Although both are generally assumed to be recent introductions, they are widespread on Caribbean islands and also have been proposed as natural colonizers. We obtained nucleotide sequence data for both species and their closest relatives in their native and introduced ranges. Phylogenetic analyses trace the origin of E. planirostris to a small area in western Cuba, while O. septentrionalis is derived from at least two Cuban sources, one probably a remote peninsula in western Cuba. The tropical-to-temperate invasion began with colonization of the Florida Keys followed by human-mediated dispersal within peninsular Florida. The subtropical Keys may have served as an adaptive stepping stone for the successful invasion of the North American continent. PMID:21270024

  20. Chytridiomycosis in wild frogs from southern Costa Rica

    Science.gov (United States)

    Lips, Karen R.; Green, D.E.; Papendick, R.

    2003-01-01

    In 1993, the amphibian fauna of Las Tablas, Costa Rica, began to decline, and by 1998 approximately 50% of the species formerly present could no longer be found. Three years later, at the Reserva Forestal Fortuna, in western Panama, a site approximately 75 km east southeast of Las Tablas, KRL encountered a mass die-off of amphibians and a subsequent decline in abundance and species richness. The epidemiological features of the anuran population declines and die-offs at both sites were similar, suggesting a similar cause. Herein we document the presence of the fungus, Batrachochytrium dendrobatidis, in dead and dying wild frogs collected at Las Tablas just prior to population declines of several anuran species.

  1. Ciliary function of the frog oro-pharyngeal epithelium.

    Science.gov (United States)

    Aiello, E; Sleigh, M

    1977-03-09

    The palate epithelium of the frog was examined by scanning electron microscopy, light microscopy and high speed cine micrography. The cilia remain stationary for much of time in the end-of-effective stroke position. Each beat cycle begins with a forwardly-directed recovery stroke lasting about 60 ms, followed by an effective stroke towards the oesophagus lasting about 12 ms. Activity can often be correlated with the presence of mucus, which is carried as strands on the tips of the ciliary effective strokes whilst the recovery strokes move beneath the mucus. Coordination of ciliary activity was very variable; local antiplectic metachrony of the recovery strokes could almost always be seen, and on very active epithelia effective strokes were associated with approximately diaplectic waves (either to left or right), but any particular pattern of coordinated activity was transient and quickly transformed to another pattern. Beating and coordination of these short cilia were compared with those of cilia propelling water.

  2. Endocrine control of active sodium transport across frog skin

    International Nuclear Information System (INIS)

    Maetz, J.

    1959-01-01

    I. Action of the neurohypophyseal peptides on sodium transport. 1) On Rana Esculenta, oxytocin alone is active on the sodium transport (not vaso pressin). 2) The post hypophysis of R.e. contains an hormonal factor even more specific on Na transport (12 times more active than oxytocin). 3) This new factor must be closely related to oxytocin. II. Action of the adrenal corticoids. 1) The skin of frogs adapted to a salt-rich external medium, shows a considerable diminution in sodium uptake. 2) This decreased sodium uptake is brought back to normal by the injections of aldosterone. 3) This suggests that salt loading of amphibians (as well as mammals) inhibits the mineralocorticoid activity of the adrenals. (author) [fr

  3. Genome evolution in the allotetraploid frog Xenopus laevis.

    Science.gov (United States)

    Session, Adam M; Uno, Yoshinobu; Kwon, Taejoon; Chapman, Jarrod A; Toyoda, Atsushi; Takahashi, Shuji; Fukui, Akimasa; Hikosaka, Akira; Suzuki, Atsushi; Kondo, Mariko; van Heeringen, Simon J; Quigley, Ian; Heinz, Sven; Ogino, Hajime; Ochi, Haruki; Hellsten, Uffe; Lyons, Jessica B; Simakov, Oleg; Putnam, Nicholas; Stites, Jonathan; Kuroki, Yoko; Tanaka, Toshiaki; Michiue, Tatsuo; Watanabe, Minoru; Bogdanovic, Ozren; Lister, Ryan; Georgiou, Georgios; Paranjpe, Sarita S; van Kruijsbergen, Ila; Shu, Shengquiang; Carlson, Joseph; Kinoshita, Tsutomu; Ohta, Yuko; Mawaribuchi, Shuuji; Jenkins, Jerry; Grimwood, Jane; Schmutz, Jeremy; Mitros, Therese; Mozaffari, Sahar V; Suzuki, Yutaka; Haramoto, Yoshikazu; Yamamoto, Takamasa S; Takagi, Chiyo; Heald, Rebecca; Miller, Kelly; Haudenschild, Christian; Kitzman, Jacob; Nakayama, Takuya; Izutsu, Yumi; Robert, Jacques; Fortriede, Joshua; Burns, Kevin; Lotay, Vaneet; Karimi, Kamran; Yasuoka, Yuuri; Dichmann, Darwin S; Flajnik, Martin F; Houston, Douglas W; Shendure, Jay; DuPasquier, Louis; Vize, Peter D; Zorn, Aaron M; Ito, Michihiko; Marcotte, Edward M; Wallingford, John B; Ito, Yuzuru; Asashima, Makoto; Ueno, Naoto; Matsuda, Yoichi; Veenstra, Gert Jan C; Fujiyama, Asao; Harland, Richard M; Taira, Masanori; Rokhsar, Daniel S

    2016-10-20

    To explore the origins and consequences of tetraploidy in the African clawed frog, we sequenced the Xenopus laevis genome and compared it to the related diploid X. tropicalis genome. We characterize the allotetraploid origin of X. laevis by partitioning its genome into two homoeologous subgenomes, marked by distinct families of 'fossil' transposable elements. On the basis of the activity of these elements and the age of hundreds of unitary pseudogenes, we estimate that the two diploid progenitor species diverged around 34 million years ago (Ma) and combined to form an allotetraploid around 17-18 Ma. More than 56% of all genes were retained in two homoeologous copies. Protein function, gene expression, and the amount of conserved flanking sequence all correlate with retention rates. The subgenomes have evolved asymmetrically, with one chromosome set more often preserving the ancestral state and the other experiencing more gene loss, deletion, rearrangement, and reduced gene expression.

  4. Asymmetrical permeability of the integument of tree frogs (Hylidae).

    Science.gov (United States)

    Yorio, T; Bentley, P J

    1977-04-01

    The skin from four species of North American tree frogs (Hylidae) was found in vitro, to be remarkably permeable to water in the presence or absence of the neurohypophysial hormone vasotocin. This property was, however, only seen in preparations from the ventral integument; osmotic water movement across the dorsal skin was negligible. The ionic permeability, reflected by the electrical resistance, was also much greater in the ventral skin. Unidirectional fluxes of 22Na, 36Cl, 14C-urea and tritiated water were measured in vitro in a single species, Agalychnis dacnicolor Cope. The ventral skin was 10-20 times more permeable to these molecules than the dorsal skin. The short-circuit current (usually reflecting active transmural Na transport) across the ventral skin was increased by aldosterone and vasotocin but these responses were absent on the dorsal side. The lipid content of the dorsal skin was four times greater than that on the ventral surface.

  5. The imprint of Late Holocene tectonic reactivation on a megafan landscape in the northern Amazonian wetlands

    Science.gov (United States)

    Rossetti, D. F.; Valeriano, M. M.; Gribel, R.; Cohen, M. C. L.; Tatumi, S. H.; Yee, M.

    2017-10-01

    The modern Amazonian ecosystem outcomes from the complex interplay of different factors performed over the geological history, with tectonics being long speculated as perhaps a fundamental one. Nevertheless, areas where tectonic activity can be fully characterized are still scarce in view of the large dimension of this region. In this work, we investigate the signature of neotectonics in one megafan paleolandform that typifies a large sector of the Negro-Branco basin in northern Amazonia. The approach joined regional morphostructural descriptions of the Viruá megafan surface and the acquisition of topographic, sedimentological, and chronological data focusing on the central sector of the megafan. The results revealed an abundance of rivers that form dendritic, subdendritic, and trellis patterns. These rivers also have numerous straight segments, orthogonal junctions, and orthogonal shifts in courses. Structural lineaments, defined by straight channels and also straight lake margins, are aligned along the NW-SE and NE-SW directions that are coincidental with the main regional structural pattern in Amazonia. This study also led to recognize two large areas of lower topography in the south-central part of the megafan that consist of rectangular depressions parallel to the morphostructural lineaments. A sedimentological survey indicated that cores extracted external to the largest depression have only distributary channel and overbank sand sheet megafan deposits. Optically stimulated luminescence (OSL) ages ranged from 17.5 ± 2.0 to 46.9 ± 3.4 ky and radiocarbon ages ranged from 5.9-5.7 to 20.1-19.6 cal ky BP. In contrast, cores extracted within the depression consisted of fluvial deposits younger than 2.1-1.9 cal ky BP that increased in thickness toward the central part of the depression. We propose that the studied megafan was affected by tectonic reactivation until at least a couple thousand years ago. Tectonics would have produced subsiding areas more prone to

  6. Misalignment of Lava Flows from Topographic Slope Directions Reveals Late Amazonian Deformation at Arsia Mons, Mars

    Science.gov (United States)

    Waring, B. A.; Chadwick, J.; McGovern, P. J., Jr.; Tucker, W.

    2017-12-01

    Arsia Mons is the southernmost of the three large Tharsis Montes near the equator of Mars and one of the largest volcanoes in the solar system. The main edifice of Arsia is about 440 km in diameter, the summit is over 9 km above the surrounding plains and has a pronounced 110 km caldera. Like the other Tharsis volcanoes, Arsia has a large, Late Amazonian glacial deposit on its NW flank. Previous crater retention studies for lava flows on Arsia have shown that the volcano experienced significant volcanic activity in the past 200 Ma. In this study, numerous long (>25 km), thin lava flows on the plains surrounding Arsia were mapped and used as indicators of the topographic slope direction at the time of their emplacement. The azimuthal orientation of each flow was compared with the present-day slope directions on the surrounding plains, derived from Mars Orbiter Laser Altimeter (MOLA) topographic data. The results reveal regions around Arsia where the flows no longer conform to the topography, indicating deformation in the time since the flows where emplaced. In a region of Daedalia Planum to the SE of Arsia, modern slope directions adjacent to 40 long lava flows are consistently misaligned from the paleo-slopes indicated by the lava flow orientations, with an angular offset that averages 7.2° in the clockwise direction. Crater size-frequency measurements for these tilted plains using CraterStats software indicate that the deformation responsible for the misaligned flows took place since 330 ± 10 Ma. Conversely, part of Daedalia Planum to the southwest of Arsia is younger, with a crater retention age of 160 ± 6 Ma, and this area shows no consistent flow-topography misalignments. These observations suggest that extensive regional deformation occurred between the two dates, consistent with other evidence for significant volcanism at Arsia in the Late Amazonian at about 200 Ma. Geophysical modelling using the finite element program COMSOL Multiphysics is planned to

  7. Studying the Effects of Amazonian Land Cover Change on Glacier Mass Balance in the Tropical Andes

    Science.gov (United States)

    Mark, B. G.; Fernandez, A.; Gabrielli, P.; Montenegro, A.; Postigo, J.; Hellstrom, R. A.

    2017-12-01

    Recent research has highlighted several ongoing environmental changes occurring across Tropical South America, including Andean glacier retreat, drought, as well as changes in land-use and land-cover. As the regional climate of the area is mostly characterized by land-ocean interactions, the atmospheric convection in the Amazon, and the effect of the Andes on circulation patterns, it follows that changes in one of those regions may affect the other. Most scholars who have studied the causes of tropical glaciers' fluctuations have not analyzed the linkages with changes in the Amazon with the same attention paid to the influence of Pacific sea surface temperature. Here we study the response of glacier surface mass balance in the Cordillera Blanca, Peru (10°S), to a scenario where the Amazonian rainforest is replaced by savannas. We ran climatic simulations at 2-km spatial resolution utilizing the Weather Research and Forecasting (WRF) model considering two scenarios: (a) control (CRTL), with today's rainforest extent; and (b) land cover change (LCC), where all the rainforest was replaced by savanna. WRF output was in turn ingested into a glacier energy and mass balance (GEMB) model that we validate by reconstructing both the accumulated mass balance from available observations, and the altitudinal distribution of mass balance in the region. Seasonal comparison between CRTL and LCC scenarios indicates that forest replacement by savanna results in more positive glacier mass balance. This shift to more positive mass balance contrasts with a (WRF) modeled rise in the elevation of the freezing line (0°C) between 30 to 120 m for the LCC scenario. Our results are surprising because most previous studies have shown that reducing Amazon forest cover diminishes rainfall and increases temperature, suggesting that glaciers should lose mass. We hypothesize and discuss implications of possible land-atmospheric processes that might drive this tropical glacier response to

  8. Above- and below-ground net primary productivity across ten Amazonian forests on contrasting soils

    Directory of Open Access Journals (Sweden)

    L. E. O. C. Aragão

    2009-12-01

    Full Text Available The net primary productivity (NPP of tropical forests is one of the most important and least quantified components of the global carbon cycle. Most relevant studies have focused particularly on the quantification of the above-ground coarse wood productivity, and little is known about the carbon fluxes involved in other elements of the NPP, the partitioning of total NPP between its above- and below-ground components and the main environmental drivers of these patterns. In this study we quantify the above- and below-ground NPP of ten Amazonian forests to address two questions: (1 How do Amazonian forests allocate productivity among its above- and below-ground components? (2 How do soil and leaf nutrient status and soil texture affect the productivity of Amazonian forests? Using a standardized methodology to measure the major elements of productivity, we show that NPP varies between 9.3±1.3 Mg C ha−1 yr−1 (mean±standard error, at a white sand plot, and 17.0±1.4 Mg C ha−1 yr−1 at a very fertile Terra Preta site, with an overall average of 12.8±0.9 Mg C ha−1 yr−1. The studied forests allocate on average 64±3% and 36±3% of the total NPP to the above- and below-ground components, respectively. The ratio of above-ground and below-ground NPP is almost invariant with total NPP. Litterfall and fine root production both increase with total NPP, while stem production shows no overall trend. Total NPP tends to increase with soil phosphorus and leaf nitrogen status. However, allocation of NPP to below-ground shows no relationship to soil fertility, but appears to decrease with the increase of soil clay content.

  9. Diversity and physiological characterization of D-xylose-fermenting yeasts isolated from the Brazilian Amazonian Forest.

    Directory of Open Access Journals (Sweden)

    Raquel M Cadete

    Full Text Available BACKGROUND: This study is the first to investigate the Brazilian Amazonian Forest to identify new D-xylose-fermenting yeasts that might potentially be used in the production of ethanol from sugarcane bagasse hemicellulosic hydrolysates. METHODOLOGY/PRINCIPAL FINDINGS: A total of 224 yeast strains were isolated from rotting wood samples collected in two Amazonian forest reserve sites. These samples were cultured in yeast nitrogen base (YNB-D-xylose or YNB-xylan media. Candida tropicalis, Asterotremella humicola, Candida boidinii and Debaryomyces hansenii were the most frequently isolated yeasts. Among D-xylose-fermenting yeasts, six strains of Spathaspora passalidarum, two of Scheffersomyces stipitis, and representatives of five new species were identified. The new species included Candida amazonensis of the Scheffersomyces clade and Spathaspora sp. 1, Spathaspora sp. 2, Spathaspora sp. 3, and Candida sp. 1 of the Spathaspora clade. In fermentation assays using D-xylose (50 g/L culture medium, S. passalidarum strains showed the highest ethanol yields (0.31 g/g to 0.37 g/g and productivities (0.62 g/L · h to 0.75 g/L · h. Candida amazonensis exhibited a virtually complete D-xylose consumption and the highest xylitol yields (0.55 g/g to 0.59 g/g, with concentrations up to 25.2 g/L. The new Spathaspora species produced ethanol and/or xylitol in different concentrations as the main fermentation products. In sugarcane bagasse hemicellulosic fermentation assays, S. stipitis UFMG-XMD-15.2 generated the highest ethanol yield (0.34 g/g and productivity (0.2 g/L · h, while the new species Spathaspora sp. 1 UFMG-XMD-16.2 and Spathaspora sp. 2 UFMG-XMD-23.2 were very good xylitol producers. CONCLUSIONS/SIGNIFICANCE: This study demonstrates the promise of using new D-xylose-fermenting yeast strains from the Brazilian Amazonian Forest for ethanol or xylitol production from sugarcane bagasse hemicellulosic hydrolysates.

  10. Ghrelin Receptor in Two Species of Anuran Amphibian, Bullfrog (Rana catesbeiana), and Japanese Tree Frog (Hyla japonica)

    OpenAIRE

    Kaiya, Hiroyuki; Koizumi, Yasushi; Konno, Norifumi; Yamamoto, Kazutoshi; Uchiyama, Minoru; Kangawa, Kenji; Miyazato, Mikiya

    2011-01-01

    We identified cDNA encoding a functional growth hormone secretagogue-receptor 1a (GHS-R1a, ghrelin receptor) in two species of anuran amphibian, bullfrog (Rana catesbeiana) and Japanese tree frog (Hyla japonica). Deduced receptor protein for bullfrog and Japanese tree frog (tree frog) was comprised of 374- and 371-amino acids, respectively. The two receptors showed 86% identity with each other, and phylogenetic analysis revealed that the two receptors belong to the same category with tetrapod...

  11. Clinical signs, pathology and dose-dependent survival of adult wood frogs, Rana sylvatica, inoculated orally with frog virus 3 Ranavirus sp., Iridoviridae.

    Science.gov (United States)

    Forzn, Mara J; Jones, Kathleen M; Vanderstichel, Raphal V; Wood, John; Kibenge, Frederick S B; Kuiken, Thijs; Wirth, Wytamma; Ariel, Ellen; Daoust, Pierre-Yves

    2015-05-01

    Amphibian populations suffer massive mortalities from infection with frog virus 3 FV3, genus Ranavirus, family Iridoviridae, a pathogen also involved in mortalities of fish and reptiles. Experimental oral infection with FV3 in captive-raised adult wood frogs, Rana sylvatica Lithobates sylvaticus, was performed as the first step in establishing a native North American animal model of ranaviral disease to study pathogenesis and host response. Oral dosing was successful LD50 was 10(2.93 2.423.44) p.f.u. for frogs averaging 35mm in length. Onset of clinical signs occurred 614days post-infection p.i. median 11 days p.i. and time to death was 1014 days p.i. median 12 days p.i.. Each tenfold increase in virus dose increased the odds of dying by 23-fold and accelerated onset of clinical signs and death by approximately 15. Ranavirus DNA was demonstrated in skin and liver of all frogs that died or were euthanized because of severe clinical signs. Shedding of virus occurred in faeces 710 days p.i. 34.5days before death and skin sheds 10 days p.i. 01.5days before death of some frogs dead from infection. Most common lesions were dermal erosion and haemorrhages haematopoietic necrosis in bone marrow, kidney, spleen and liver and necrosis in renal glomeruli, tongue, gastrointestinal tract and urinary bladder mucosa. Presence of ranavirus in lesions was confirmed by immunohistochemistry. Intracytoplasmic inclusion bodies probably viral were present in the bone marrow and the epithelia of the oral cavity, gastrointestinal tract, renal tubules and urinary bladder. Our work describes a ranaviruswood frog model and provides estimates that can be incorporated into ranavirus disease ecology models. © 2015 The Authors.

  12. Muscle fatigue in frog semitendinosus: alterations in contractile function

    Science.gov (United States)

    Thompson, L. V.; Balog, E. M.; Riley, D. A.; Fitts, R. H.

    1992-01-01

    The purpose of this study was to characterize the contractile properties of the frog semitendinosus (ST) muscle before and during recovery from fatigue, to relate the observed functional changes to alterations in specific steps in the crossbridge model of muscle contraction, and to determine how fatigue affects the force-frequency relationship. The frog ST (22 degrees C) was fatigued by direct electrical stimulation with 100-ms 150-Hz trains at 1/s for 5 min. The fatigue protocol reduced peak twitch (Pt) and tetanic (Po) force to 32 and 8.5% of initial force, respectively. The decline in Pt was less than Po, in part due to a prolongation in the isometric contraction time (CT), which increased to 300% of the initial value. The isometric twitch duration was greatly prolonged as reflected by the lengthened CT and the 800% increase in the one-half relaxation time (1/2RT). Both Pt and Po showed a biphasic recovery, a rapid initial phase (2 min) followed by a slower (40 min) return to the prefatigue force. CT and 1/2RT also recovered in two phases, returning to 160 and 265% of control in the first 5 min. CT returned to the prefatigue value between 35 and 40 min, whereas even at 60 min 1/2RT was 133% of control. The maximal velocity of shortening, determined by the slack test, was significantly reduced [from 6.7 +/- 0.5 to 2.5 +/- 0.4 optimal muscle length/s] at fatigue. The force-frequency relationship was shifted to the left, so that optimal frequency for generating Po was reduced.(ABSTRACT TRUNCATED AT 250 WORDS).

  13. Apical Na+ permeability of frog skin during serosal Cl- replacement.

    Science.gov (United States)

    Leibowich, S; DeLong, J; Civan, M M

    1988-05-01

    Gluconate substitution for serosal Cl- reduces the transepithelial short-circuit current (Isc) and depolarizes short-circuited frog skins. These effects could result either from inhibition of basolateral K+ conductance, or from two actions to inhibit both apical Na+ permeability (PapNa) and basolateral pump activity. We have addressed this question by studying whole-and split-thickness frog skins. Intracellular Na+ concentration (CcNa) and PapNa have been monitored by measuring the current-voltage relationship for apical Na+ entry. This analysis was conducted by applying trains of voltage pulses, with pulse durations of 16 to 32 msec. Estimates of PapNa and CcNa were not detectably dependent on pulse duration over the range 16 to 80 msec. Serosal Cl- replacement uniformly depolarized short-circuited tissues. The depolarization was associated with inhibition of Isc across each split skin, but only occasionally across the whole-thickness preparations. This difference may reflect the better ionic exchange between the bulk medium and the extracellular fluid in contact with the basolateral membranes, following removal of the underlying dermis in the split-skin preparations. PapNa was either unchanged or increased, and CcNa either unchanged or reduced after the anionic replacement. These data are incompatible with the concept that serosal Cl- replacement inhibits PapNa and Na,K-pump activity. Gluconate substitution likely reduces cell volume, triggering inhibition of the basolateral K+ channels, consistent with the data and conclusions of S.A. Lewis, A.G. Butt, M.J. Bowler, J.P. Leader and A.D.C. Macknight (J. Membrane Biol. 83:119-137, 1985) for toad bladder. The resulting depolarization reduces the electrical force favoring apical Na+ entry. The volume-conductance coupling serves to conserve volume by reducing K+ solute loss. Its molecular basis remains to be identified.

  14. Tsimane' Amazonian Panel Study (TAPS): the first 5 years (2002-2006) of socioeconomic, demographic, and anthropometric data available to the public.

    Science.gov (United States)

    Leonard, William R; Godoy, Ricardo

    2008-07-01

    The Tsimane' Amazonian Panel Study (TAPS) is making available the first five years (2002-2006, inclusive) of annual socioeconomic, demographic, and anthropometric data available to the public. The information comes from a foraging-farming society of native Amazonians in Bolivia and includes 13 villages, 332 households, and 1985 people who have been tracked annually since 2002. The article provides a brief overview of the data covered and the steps needed to access the data.

  15. Differential Expression of Myogenic Regulatory Factor Genes in the Skeletal Muscles of Tambaqui Colossoma macropomum (Cuvier 1818) from Amazonian Black and Clear Water

    OpenAIRE

    Alves-Costa, F. A.; Barbosa, C. M.; Aguiar, R. C. M.; Mareco, E. A.; Dal-Pai-Silva, M.

    2013-01-01

    Hypothesizing that the Amazonian water system differences would affect the expression of muscle growth-related genes in juvenile tambaqui Colossoma macropomum (Cuvier 1818), this study aimed to analyze the morphometric data and expression of myogenic regulatory factors (MRFs) in the white and red muscle from tambaqui obtained from clear and black Amazonian water systems. All of the MRF transcript levels (myod, myf5, myogenin, and mrf4) were significantly lower in the red muscle from black wat...

  16. The palms in the traditional knowledge of indigenous Amazonian group Aguaruna-Huambisa

    Directory of Open Access Journals (Sweden)

    Fernando Roca Alcázar

    2014-03-01

    Full Text Available The traditional knowledge of indigenous peoples shows a different vision of the world to that of the western society. The knowledge about palms of the Aguaruna-huambisa groups living in the northwestern Peruvian forests express their palm knowledge in a particular way. Many researchers hypothesize that the Aguaruna– huambisa society, due to great botanical knowledge, are able to recognize generic taxa of palms. Scientific botanical knowledge and traditional knowledge lead to divergent perceptions of the Amazonian flora and to different ways to expressing them. The palm generic taxon, SHINKI in aguaruna language, is not recognized, but other generic taxa such as tree, vine and herb clearly appear in the traditional knowledge of this society.

  17. Bioactive properties of Tynanthus panurensis (Bureau) Sanwith bark extract, the Amazonian "clavo huasca".

    Science.gov (United States)

    Morales, Lidia; Acero, Nuria; Galán, Antonio; Perez-García, Carmen; Alguacil, Luis Fernando; Muñoz-Mingarro, Dolores

    2011-09-01

    Tynanthus panurensis (Bureau) Sanwith (Bignoniaceae) is a liana vine used in traditional Amazonian medicine as a tonic and energizer as well as a treatment for rheumatism. These traditional indications prompted this study of the antioxidant and anti-inflammatory activities of T. panurensis bark extract (ETP). Phytochemical analysis of ETP showed the presence of saponins and a high concentration of phenols and flavonoids. A battery of in vitro tests revealed that the extract has free radical-scavenging antioxidant properties and reduces microsomal lipid peroxidation, uric acid synthesis, and tumor necrosis factor-α production. The anti-inflammatory properties of ETP were further confirmed in vivo in a rat carrageenan edema model, in which the extract exhibited a potent activity. These results support the idea that T. panurensis bark extract could be beneficial for treating inflammation and are in agreement with one of the main traditional uses of this plant.

  18. Access to health care in relation to socioeconomic status in the Amazonian area of Peru

    DEFF Research Database (Denmark)

    Kristiansson, Charlotte; Gotuzzo, Eduardo; Rodriguez, Hugo

    2009-01-01

    in relation to household socioeconomic status for children in two small Amazonian urban communities of Peru; Yurimaguas, Department of Loreto and Moyobamba, Department of San Martin, Peru. METHODS: Cross-sectional study design included household interviews. Caregivers of 780 children aged 6-72 months...... in Yurimaguas and 793 children of the same age in Moyobamba were included in the study. Caregivers were interviewed on health care seeking strategies (public/private sectors; formal/informal providers), and medication for their children in relation to reported symptoms and socio-economic status. Self......-reported symptoms were classified into illnesses based on the IMCI algorithm (Integrated Management of Childhood Ilness). Wealth was used as a proxy indicator for the economic status. Wealth values were generated by Principal Component Analysis using household assets and characteristics. RESULTS: Significantly more...

  19. Potential application in biocatalysis of mycelium-bound lipases from Amazonian fungi

    Energy Technology Data Exchange (ETDEWEB)

    Zanotto, Sandra P.; Romano, Israel P.; Lisboa, Lilian U.S.; Duvoisin Junior, Sergio; Lima, Fabiana A.; Silva, Soraya F.; Alburquerque, Patricia M. [Universidade Federal do Amazonas (UFAM), Manaus, AM (Brazil). Programa em Biotecnologia e Recursos Naturais da Amazonia. Lab. de Biorganica; Martins, Mayra K. [Centro de Biotecnologia do Amazonas, Manaus, AM (Brazil)

    2009-07-01

    In this study, 212 fungi were isolated from Amazon region plants, aiming to obtain mycelium bound-lipase-producing biocatalysts. These isolates were submitted to hydrolytic and synthetic activity assays. When submitted to the tributyrine substrate test, 87% of the isolates showed hydrolytic activity. Of these, 30% showed good growth in lipase inducing liquid media and were submitted to evaluation of synthetic activity in esterification and transesterification reactions in organic solvents. The nine fungi which had the best synthetic activity were evaluated in the (R, S)-2-octanol resolution reaction, in order to verify the enantioselectivity of mycelium-bound lipases. The isolate UEA{sub 1}15 was the most versatile biocatalyst, showing good performance in esterification reactions (conversion > 90%) and good ability for the resolution of (R, S)-2-octanol (ees 29%; eep 99%; c 22%; E > 200). Thus, this study has demonstrated the great potential of the Amazonian fungi as lipase suppliers for biocatalysts.(author)

  20. Ecological suitability and spatial distribution of five Anopheles species in Amazonian Brazil.

    Science.gov (United States)

    McKeon, Sascha N; Schlichting, Carl D; Povoa, Marinete M; Conn, Jan E

    2013-06-01

    Seventy-six sites characterized in Amazonian Brazil revealed distinct habitat diversification by examining the environmental factors associated with the distribution and abundance of five anopheline species (Diptera: Culicidae) in the subgenus Nyssorhynchus. These included three members of the Albitarsis Complex, Anopheles oryzalimnetes, Anopheles marajoara, Anopheles janconnae; Anopheles triannulatus, and Anopheles goeldii. Anopheles janconnae abundance had a positive correlation to water flow and a negative relationship to sun exposure. Abundance of An. oryzalimentes was associated with water chemistry. Anopheles goeldii larvae were abundant in shaded, more saline waters. Anopheles marajoara and An. triannulatus were negatively associated with available resources, although An. marajoara also showed several local correlations. These analyses suggest An. triannulatus is a habitat generalist, An. oryzalimentes and An. janconnae are specialists, and An. marajoara and An. goeldii could not be easily classified either way. Correlations described herein provide testable hypotheses for future research and identifying habitats for vector control.

  1. The association of genetic markers and malaria infection in the Brazilian Western Amazonian region

    Directory of Open Access Journals (Sweden)

    B Beiguelman

    2003-06-01

    Full Text Available Almost all individuals (182 belonging to an Amazonian riverine population (Portuchuelo, RO, Brazil were investigated for ascertaining data on epidemiological aspects of malaria. Thirteen genetic blood polymorphisms were investigated (ABO, MNSs, Rh, Kell, and Duffy systems, haptoglobins, hemoglobins, and the enzymes glucose-6-phosphate dehydrogenase, glyoxalase, phosphoglucomutase, carbonic anhydrase, red cell acid phosphatase, and esterase D. The results indicated that the Duffy system is associated with susceptibility to malaria, as observed in other endemic areas. Moreover, suggestions also arose indicating that the EsD and Rh loci may be significantly associated with resistance to malaria. If statistical type II errors and sample stratification could be ruled out, hypotheses on the existence of a causal mechanism or an unknown closely linked locus involved in susceptibility to malaria infection may explain the present findings.

  2. Antioxidant Potential and Modulatory Effects of Restructured Lipids from the Amazonian Palms on Liver Cells

    Directory of Open Access Journals (Sweden)

    Andrea de Oliveira Falcão

    2017-01-01

    Full Text Available Enzymatic interesterification is used to manipulate oil and fat in order to obtain improved restructured lipids with desired technological properties. However, with raw materials containing significant amounts of bioactive compounds, the influence of this enzymatic process on the bioactivity of the final product is still not clear. Thus, the aim of this study is to evaluate the antioxidant potential and modulatory effects of two raw materials from the Amazonian area, buriti oil and murumuru fat, before and after lipase interesterification, on human hepatoma cells (HepG2. The results indicate that minor bioactive compounds naturally found in the raw materials and their antioxidant capacity are preserved after enzymatic interesterification, and that the restructured lipids modulate HepG2 endogenous antioxidant enzyme.

  3. Potential application in biocatalysis of mycelium-bound lipases from Amazonian fungi

    International Nuclear Information System (INIS)

    Zanotto, Sandra P.; Romano, Israel P.; Lisboa, Lilian U.S.; Duvoisin Junior, Sergio; Lima, Fabiana A.; Silva, Soraya F.; Alburquerque, Patricia M.

    2009-01-01

    In this study, 212 fungi were isolated from Amazon region plants, aiming to obtain mycelium bound-lipase-producing biocatalysts. These isolates were submitted to hydrolytic and synthetic activity assays. When submitted to the tributyrine substrate test, 87% of the isolates showed hydrolytic activity. Of these, 30% showed good growth in lipase inducing liquid media and were submitted to evaluation of synthetic activity in esterification and transesterification reactions in organic solvents. The nine fungi which had the best synthetic activity were evaluated in the (R, S)-2-octanol resolution reaction, in order to verify the enantioselectivity of mycelium-bound lipases. The isolate UEA 1 15 was the most versatile biocatalyst, showing good performance in esterification reactions (conversion > 90%) and good ability for the resolution of (R, S)-2-octanol (ees 29%; eep 99%; c 22%; E > 200). Thus, this study has demonstrated the great potential of the Amazonian fungi as lipase suppliers for biocatalysts.(author)

  4. Submerged in darkness: adaptations to prolonged submergence by woody species of the Amazonian floodplains.

    Science.gov (United States)

    Parolin, Pia

    2009-01-01

    In Amazonian floodplain forests, >1000 tree species grow in an environment subject to extended annual submergence which can last up to 9 months each year. Water depth can reach 10 m, fully submerging young and also adult trees, most of which reproduce during the flood season. Complete submergence occurs regularly at the seedling or sapling stage for many species that colonize low-lying positions in the flooding gradient. Here hypoxic conditions prevail close to the water surface in moving water, while anaerobic conditions are common in stagnant pools. Light intensities in the floodwater are very low. Despite a lack of both oxygen and light imposed by submergence for several months, most leafed seedlings survive. Furthermore, underwater growth has also been observed in several species in the field and under experimental conditions. The present article assesses how these remarkable plants react to submergence and discusses physiological mechanisms and anatomical adaptations that may explain their success.

  5. Qualitative assessment of visuospatial errors in mercury-exposed Amazonian children

    DEFF Research Database (Denmark)

    Chevrier, Cécile; Sullivan, Kimberly; White, Roberta F.

    2009-01-01

    In order to better define the effects of methylmercury (MeHg) exposure on neurodevelopment, qualitative error types observed in the responses of exposed children to the Stanford-Binet Copying Test were categorized and quantified using raw data from two studies of 395 Amazonian children aged 7...... mechanisms of observed effects based on convergent evidence of MeHg-related qualitative outcomes in the two studies and (2) to explore possible cultural determinants of test response based on divergent outcomes in the two countries. Multiple linear and logistic regression analyses were performed....../g; this effect appeared to be stronger in the younger children. Risk of committing one or more errors of rotation, simplification or perseveration in the drawings increased with hair-mercury concentration in both cultural settings, providing convergent evidence of specific types of MeHg-related neurocognitive...

  6. Securitization, alterity, and the stateHuman (in)security on an Amazonian frontier.

    Science.gov (United States)

    Brightman, Marc; Grotti, Vanessa

    2014-12-01

    Focusing on the region surrounding the Maroni River, which forms the border between Suriname and French Guiana, we examine how relations between different state and non-state social groups are articulated in terms of security. The region is characterised by multiple "borders" and frontiers of various kinds, the state boundary having the features of an interface or contact zone. Several key collectivities meet in this border zone: native Amazonians, tribal Maroon peoples, migrant Brazilian gold prospectors, and metropolitan French state functionaries. We explore the relationships between these different sets of actors and describe how their mutual encounters center on discourses of human and state security, thus challenging the commonly held view of the region as a stateless zone and showing that the "human security" of citizens from the perspective of the state may compete with locally salient ideas or experiences of well-being.

  7. Chromosome number and karyotype of the endangered Amazonian woody Centrolobium paraense Tul. species

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    Nair Dahmer

    2009-01-01

    Full Text Available Centrolobium paraense Tul., popularly known in Brazil as “pau-rainha”, is a species with a high timberpotential, presently endangered due to deforestation of the Amazonian region and indiscriminate wood extraction. Chromosomenumber and karyotype morphology of this species are presented for the first time. All the individuals of the three populationsanalyzed are diploid, with 2n=2x=20 chromosomes. The chromosomes ranging from ca. 1.7 to 4 μm in size. The karyotypeis composed of three metacentric, three submetacentric (one with a satellite on the short arm, three acrocentric and onesubacrocentric chromosome pairs. Other Centrolobium species and populations should be analyzed in order to assess theextent of intraspecific and interspecific variation in chromosome number and morphology, if any.

  8. Frog species richness, composition and beta-diversity in coastal Brazilian restinga habitats

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    CFD. Rocha

    Full Text Available We studied the species richness and composition of frogs in 10 restinga habitats (sand dune environments dominated by herbaceous and shrubby vegetation along approximately 1500 km of coastal areas of three Brazilian States: Rio de Janeiro (Grumari, Maricá, Massambaba, Jurubatiba and Grussaí, Espírito Santo (Praia das Neves and Setiba and Bahia (Prado and Trancoso. We estimated beta-diversity and similarity among areas and related these parameters to geographic distance between areas. All areas were surveyed with a similar sampling procedure. We found 28 frog species belonging to the families Hylidae, Microhylidae, Leptodactylidae and Bufonidae. Frogs in restingas were in general nocturnal with no strictly diurnal species. The richest restinga was Praia das Neves (13 species, followed by Grussaí and Trancoso (eight species in each. The commonest species in the restingas was Scinax alter (found in eight restingas, followed by Aparasphenodon brunoi (seven areas. Our data shows that richness and composition of frog communities vary consistently along the eastern Brazilian coast and, in part, the rate of species turnover is affected by the distance among areas. Geographic distance explained approximately 12% of species turnover in restingas and about 9.5% of similarity among frog assemblages. Although geographic distance somewhat affects frog assemblages, other factors (e.g. historical factors, disturbances seem to be also involved in explaining present frog assemblage composition in each area and species turnover among areas. The frog fauna along restinga habitats was significantly nested (matrix community temperature = 26.13°; p = 0.007. Our data also showed that the most hospitable restinga was Praia das Neves and indicated that this area should be protected as a conservation unit. Frog assemblage of each area seems to partially represent a nested subset of the original assemblage, although we should not ignore the importance of historical

  9. Frog species richness, composition and beta-diversity in coastal Brazilian restinga habitats.

    Science.gov (United States)

    Rocha, C F D; Hatano, F H; Vrcibradic, D; Van Sluys, M

    2008-02-01

    We studied the species richness and composition of frogs in 10 restinga habitats (sand dune environments dominated by herbaceous and shrubby vegetation) along approximately 1500 km of coastal areas of three Brazilian States: Rio de Janeiro (Grumari, Maricá, Massambaba, Jurubatiba and Grussaí), Espírito Santo (Praia das Neves and Setiba) and Bahia (Prado and Trancoso). We estimated beta-diversity and similarity among areas and related these parameters to geographic distance between areas. All areas were surveyed with a similar sampling procedure. We found 28 frog species belonging to the families Hylidae, Microhylidae, Leptodactylidae and Bufonidae. Frogs in restingas were in general nocturnal with no strictly diurnal species. The richest restinga was Praia das Neves (13 species), followed by Grussaí and Trancoso (eight species in each). The commonest species in the restingas was Scinax alter (found in eight restingas), followed by Aparasphenodon brunoi (seven areas). Our data shows that richness and composition of frog communities vary consistently along the eastern Brazilian coast and, in part, the rate of species turnover is affected by the distance among areas. Geographic distance explained approximately 12% of species turnover in restingas and about 9.5% of similarity among frog assemblages. Although geographic distance somewhat affects frog assemblages, other factors (e.g. historical factors, disturbances) seem to be also involved in explaining present frog assemblage composition in each area and species turnover among areas. The frog fauna along restinga habitats was significantly nested (matrix community temperature = 26.13 degrees; p = 0.007). Our data also showed that the most hospitable restinga was Praia das Neves and indicated that this area should be protected as a conservation unit. Frog assemblage of each area seems to partially represent a nested subset of the original assemblage, although we should not ignore the importance of historical

  10. The Diversity of Bitter Manioc (Manihot Esculenta Crantz Cultivation in a Whitewater Amazonian Landscape

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    James A. Fraser

    2010-04-01

    Full Text Available While bitter manioc has been one of the most important staple crops in the central Amazon for thousands of years, there have been few studies of its cultivation in the fertile whitewater landscapes of this region. Anthropological research on bitter manioc cultivation in the Amazon has focused almost exclusively on long-fallow shifting cultivation in marginal upland areas of low soil fertility. This has contributed to the persistence of the oversimplified notion that because bitter manioc is well adapted to infertile upland soils; it cannot yield well in alluvial and/or fertile soils. I hypothesized that bitter manioc cultivation would be well adapted to the fertile soils of the whitewater landscapes of the central Amazon because of the centrality of this crop to subsistence in this region. In this article, I examine one such whitewater landscape, the middle Madeira River, Amazonas, Brazil, where smallholders cultivate bitter manioc on fertile Amazonian Dark Earths (ADE and floodplain soils, and on infertile Oxisols and Ultisols. In this region, cultivation on fertile soils tends to be short-cycled, characterised by short fallowing (0–6 years and shorter cropping periods (5–12 months with a predominance of low starch fast maturing “weak” landraces. By contrast, cultivation on infertile soils is normally long-cycled, characterised by longer fallows (>10 years and longer cropping periods (1–3 years with a predominance of high starch slow maturing “strong” landraces. This diversity in bitter manioc cultivation systems (landraces, fallow periods, soils demonstrates that Amazonian farmers have adapted bitter manioc cultivation to the specific characteristics of the landscapes that they inhabit. I conclude that contrary to earlier claims, there are no ecological limitations on growing bitter manioc in fertile soils, and therefore the cultivation of this crop in floodplain and ADE soils would have been possible in the pre-Columbian period.

  11. The role of Amazonian anthropogenic soils in shifting cultivation: learning from farmers' rationales

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    André B. Junqueira

    2016-03-01

    Full Text Available We evaluated farmers' rationales to understand their decision making in relation to the use of fertile anthropogenic soils, i.e., Amazonian dark earths (ADE, and for dealing with changes in shifting cultivation in Central Amazonia. We analyzed qualitative information from 196 interviews with farmers in 21 riverine villages along the Madeira River. In order to decide about crop management options to attain their livelihood objectives, farmers rely on an integrated and dynamic understanding of their biophysical and social environment. Farmers associate fallow development with higher crop yields and lower weed pressure, but ADE is always associated with high yields and high weeding requirements. Amazonian dark earths are also seen as an opportunity to grow different crops and/or grow crops in more intensified management systems. However, farmers often maintain simultaneously intensive swiddens on ADE and extensive swiddens on nonanthropogenic soils. Farmers acknowledge numerous changes in their socioeconomic environment that affect their shifting cultivation systems, particularly their growing interaction with market economies and the incorporation of modern agricultural practices. Farmers considered that shifting cultivation systems on ADE tend to be more prone to changes leading to intensification, and we identified cases, e.g., swiddens used for watermelon cultivation, in which market demand led to overintensification and resulted in ADE degradation. This shows that increasing intensification can be a potential threat to ADE and can undermine the importance of these soils for agricultural production, for the conservation of agrobiodiversity, and for local livelihoods. Given that farmers have an integrated knowledge of their context and respond to socioeconomic and agro-ecological changes in their environment, we argue that understanding farmers' knowledge and rationales is crucial to identify sustainable pathways for the future of ADE and of

  12. Enhanced canopy growth precedes senescence in 2005 and 2010 Amazonian droughts

    KAUST Repository

    Liu, Yi Y.

    2018-04-09

    Unprecedented droughts hit southern Amazonia in 2005 and 2010, causing a sharp increase in tree mortality and carbon loss. To better predict the rainforest\\'s response to future droughts, it is necessary to understand its behavior during past events. Satellite observations provide a practical source of continuous observations of Amazonian forest. Here we used a passive microwave-based vegetation water content record (i.e., vegetation optical depth, VOD), together with multiple hydrometeorological observations as well as conventional satellite vegetation measures, to investigate the rainforest canopy dynamics during the 2005 and 2010 droughts. During the onset of droughts in the wet-to-dry season (May–July) of both years, we found large-scale positive anomalies in VOD, leaf area index (LAI) and enhanced vegetation index (EVI) over the southern Amazonia. These observations are very likely caused by enhanced canopy growth. Concurrent below-average rainfall and above-average radiation during the wet-to-dry season can be interpreted as an early arrival of normal dry season conditions, leading to enhanced new leaf development and ecosystem photosynthesis, as supported by field observations. Our results suggest that further rainfall deficit into the subsequent dry season caused water and heat stress during the peak of 2005 and 2010 droughts (August–October) that exceeded the tolerance limits of the rainforest, leading to widespread negative VOD anomalies over the southern Amazonia. Significant VOD anomalies were observed mainly over the western part in 2005 and mainly over central and eastern parts in 2010. The total area with significant negative VOD anomalies was comparable between these two drought years, though the average magnitude of significant negative VOD anomalies was greater in 2005. This finding broadly agrees with the field observations indicating that the reduction in biomass carbon uptake was stronger in 2005 than 2010. The enhanced canopy growth

  13. Development of a biocompatible magnetic nanofluid by incorporating SPIONs in Amazonian oils

    Science.gov (United States)

    Gaspar, André S.; Wagner, Friedrich E.; Amaral, Vítor S.; Costa Lima, Sofia A.; Khomchenko, Vladimir A.; Santos, Judes G.; Costa, Benilde F. O.; Durães, Luísa

    2017-02-01

    Higher quality magnetic nanoparticles are needed for use as magnetic nanoprobe in medical imaging techniques and cancer therapy. Moreover, the phytochemistry benefits of some Amazonian essential oils have sparked great interest for medical treatments. In this work, a magnetic nanoprobe was developed, allying the biocompatibility and superparamagnetism of iron oxide nanoparticles (SPIONs) with benefits associated with Amazonian oils from Copaiba and Andiroba trees. SPIONs were obtained by two thermal decomposition procedures and different amounts of precursors (iron acetylacetonates). Their characterization was accomplished by Fourier transform infrared spectroscopy, thermogravimetric analysis, transmission electron microscopy (TEM), X-ray diffraction (XRD), Mössbauer spectroscopy and magnetization. The obtained nanoparticles composition and magnetic properties were not affected by the relative proportion of iron(II) and iron(III) in the precursor system. However, when changing the reducing and stabilizing agents the coating layer shows different compositions/relative weight - the more promising SPIONs have a coating mainly composed by oleylamine and an iron oxide:coating wt% ratio of 55:45. Nanoparticles size distributions were very narrow and centred in the average size of 6-7 nm. Cellular assays confirmed the biocompatibility of SPIONs and their effective internalization in human colon cancer cells. Mössbauer/XRD results indicated maghemite as their main iron oxide phase, but traces of magnetite proved to be present. Magnetization saturations of 57 emu/g at 5 K and 42 emu/g at 300 K were achieved. With incorporation of SPIONs into Copaiba and Andiroba essential oils, these values show a 4-fold decrease, but the supermagnetic behaviour is preserved providing the effective formation of a nanofluid.

  14. Impacts of Landscape Context on Patterns of Wind Downfall Damage in a Fragmented Amazonian Landscape

    Science.gov (United States)

    Schwartz, N.; Uriarte, M.; DeFries, R. S.; Gutierrez-Velez, V. H.; Fernandes, K.; Pinedo-Vasquez, M.

    2015-12-01

    Wind is a major disturbance in the Amazon and has both short-term impacts and lasting legacies in tropical forests. Observed patterns of damage across landscapes result from differences in wind exposure and stand characteristics, such as tree stature, species traits, successional age, and fragmentation. Wind disturbance has important consequences for biomass dynamics in Amazonian forests, and understanding the spatial distribution and size of impacts is necessary to quantify the effects on carbon dynamics. In November 2013, a mesoscale convective system was observed over the study area in Ucayali, Peru, a highly human modified and fragmented forest landscape. We mapped downfall damage associated with the storm in order to ask: how does the severity of damage vary within forest patches, and across forest patches of different sizes and successional ages? We applied spectral mixture analysis to Landsat images from 2013 and 2014 to calculate the change in non-photosynthetic vegetation fraction after the storm, and combined it with C-band SAR data from the Sentinel-1 satellite to predict downfall damage measured in 30 field plots using random forest regression. We then applied this model to map damage in forests across the study area. Using a land cover classification developed in a previous study, we mapped secondary and mature forest, and compared the severity of damage in the two. We found that damage was on average higher in secondary forests, but patterns varied spatially. This study demonstrates the utility of using multiple sources of satellite data for mapping wind disturbance, and adds to our understanding of the sources of variation in wind-related damage. Ultimately, an improved ability to map wind impacts and a better understanding of their spatial patterns can contribute to better quantification of carbon dynamics in Amazonian landscapes.

  15. A Molecular Survey of the Diversity of Microbial Communities in Different Amazonian Agricultural Model Systems

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    Acácio A. Navarrete

    2010-05-01

    Full Text Available The processes of land conversion and agricultural intensification are a significant cause of biodiversity loss, with consequent negative effects both on the environment and the sustainability of food production.The anthrosols associated with pre-Colombian settlements in the Amazonian region are examples of how anthropogenic activities may sustain the native populations against harsh tropical environments for human establishment, even without a previous intentionality of anthropic soil formation. In a case study (Model I—“Slash-and-Burn” the community structures detected by automated ribosomal intergenic spacer analysis (ARISA revealed that soil archaeal, bacterial and fungal communities are heterogeneous and each capable of responding differently to environmental characteristics. ARISA data evidenced considerable difference in structure existing between microbial communities in forest and agricultural soils. In a second study (Model II—“Anthropogenic Soil”, the bacterial community structures revealed by terminal restriction fragment length polymorphism (T-RFLP differed among an Amazonian Dark Earth (ADE, black carbon (BC and its adjacent non-anthropogenic oxisoil. The bacterial 16S rRNA gene (OTU richness estimated by pyrosequencing was higher in ADE than BC. The most abundant bacterial phyla in ADE soils and BC were Proteobacteria—24% ADE, 15% BC; Acidobacteria—10% ADE, 21% BC; Actinobacteria—7% ADE, 12% BC; Verrucomicrobia, 8% ADE; 9% BC; Firmicutes—3% ADE, 8% BC. Overall, unclassified bacteria corresponded to 36% ADE, and 26% BC. Regardless of current land uses, our data suggest that soil microbial community structures may be strongly influenced by the historical soil management and that anthrosols in Amazonia, of anthropogenic origins, in addition to their capacity of enhancing crop yields, may also improve microbial diversity, with the support of the black carbon, which may sustain a particular and unique habitat for the

  16. Multi-scale comparisons of tree composition in Amazonian terra firme forests

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    L. Freitas Alvarado

    2009-11-01

    Full Text Available We explored the floristic composition of terra firme forests across Amazonia using 55 plots. Firstly, we examined the floristic patterns using both genus- and species-level data and found that the species-level analysis more clearly distinguishes among forests. Next, we compared the variation in plot floristic composition at regional- and continental-scales, and found that average among-pair floristic similarity and its decay with distance behave similarly at regional- and continental-scales. Nevertheless, geographical distance had different effects on floristic similarity within regions at distances <100 km, where north-western and south-western Amazonian regions showed greater floristic variation than plots of central and eastern Amazonia. Finally, we quantified the role of environmental factors and geographical distance for determining variation in floristic composition. A partial Mantel test indicated that while geographical distance appeared to be more important at continental scales, soil fertility was crucial at regional scales within western Amazonia, where areas with similar soil conditions were more likely to share a high number of species. Overall, these results suggest that regional-scale variation in floristic composition can rival continental-scale differences within Amazonian terra firme forests, and that variation in floristic composition at both scales is influenced by geographical distance and environmental factors, such as climate and soil fertility. To fully account for regional-scale variation in continental studies of floristic composition, future floristic studies should focus on forest types poorly represented at regional scales in current datasets, such as terra firme forests with high soil fertility in north-western Amazonia.

  17. Soil charcoal as long-term pyrogenic carbon storage in Amazonian seasonal forests.

    Science.gov (United States)

    Turcios, Maryory M; Jaramillo, Margarita M A; do Vale, José F; Fearnside, Philip M; Barbosa, Reinaldo Imbrozio

    2016-01-01

    Forest fires (paleo + modern) have caused charcoal particles to accumulate in the soil vertical profile in Amazonia. This forest compartment is a long-term carbon reservoir with an important role in global carbon balance. Estimates of stocks remain uncertain in forests that have not been altered by deforestation but that have been impacted by understory fires and selective logging. We estimated the stock of pyrogenic carbon derived from charcoal accumulated in the soil profile of seasonal forest fragments impacted by fire and selective logging in the northern portion of Brazilian Amazonia. Sixty-nine soil cores to 1-m depth were collected in 12 forest fragments of different sizes. Charcoal stocks averaged 3.45 ± 2.17 Mg ha(-1) (2.24 ± 1.41 Mg C ha(-1) ). Pyrogenic carbon was not directly related to the size of the forest fragments. This carbon is equivalent to 1.40% (0.25% to 4.04%) of the carbon stocked in aboveground live tree biomass in these fragments. The vertical distribution of pyrogenic carbon indicates an exponential model, where the 0-30 cm depth range has 60% of the total stored. The total area of Brazil's Amazonian seasonal forests and ecotones not altered by deforestation implies 65-286 Tg of pyrogenic carbon accumulated along the soil vertical profile. This is 1.2-2.3 times the total amount of residual pyrogenic carbon formed by biomass burning worldwide in 1 year. Our analysis suggests that the accumulated charcoal in the soil vertical profile in Amazonian forests is a substantial pyrogenic carbon pool that needs to be considered in global carbon models. © 2015 John Wiley & Sons Ltd.

  18. Utilization and fate of phosphorus of different sources applied to cohesive soil of Amazonian periphery

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    Marta Jordana Arruda Coelho

    Full Text Available ABSTRACT In the Amazonian region, P is often a primary factor limiting sustainable agrosystems. We compared the efficiencies of local aluminous phosphate (ALP and single superphosphate (SSP under a cover of leguminous residues to determine the fate of P sources in an Amazonian soil with hardsetting characteristics. The experiment followed a randomized block design with four replications and the following treatments: ALPU, i.e. ALP plus urea (U; ALPL, i.e., ALP plus leucaena (L; SSPU, i.e., SSP plus urea; SSPL, i.e., SSP plus leucaena; and BS, i.e., bare soil (without residues. To assess the residual values of the P sources, we used a sequence of crops consisting of maize, cowpea and cassava. Both ALP and SSP exhibited low P efficiency in BS. The greatest amounts of P and N uptake in the plots where P sources and leucaena residues were added, as in those covered with leucaena residue, resulted in higher productivity levels. These differences are important for the adoption of beneficial soil management practices and the use of P sources to enhance efficiency in tropical soils. The use of residues increased the P use efficiency of both P sources, as it enhanced the uptake of both N and soluble P. The replacement of SSP with ALP may be advantageous in the second year of planting with high-demand crops, but the P of the SSP retained in the minus soluble fractions may be available if the SSP is used in P-depleting crops combined with no-tillage underneath a mulch of residues.

  19. Recent (Late Amazonian) enhanced backweathering rates on Mars: Paracratering evidence from gully alcoves

    Science.gov (United States)

    de Haas, Tjalling; Conway, Susan; Krautblatter, Michael

    2016-04-01

    Mars is believed to have been exposed to low planet-wide weathering and denudation since the Noachian period (˜4.1 - 3.7 Ga). However, the widespread occurrence of alcoves at the rim of pristine impact craters suggests locally enhanced recent backweathering rates. Here we derive Late Amazonian backweathering rates from the alcoves of 10 young equatorial and mid-latitude craters, ranging in age from 0.2 to 45 Ma. The enhanced Late Amazonian Martian backweathering rates (10-4 - 10-1 mm yr-1) are approximately one order of magnitude higher than previously reported erosion rates, and are similar to terrestrial rates inferred from Meteor crater and various Arctic and Alpine rock faces, when corrected for age. Alcoves on initially highly fractured and oversteepened crater rims following impact show enhanced backweathering rates that decline over at least 101 - 102 Myr as the crater wall stabilizes. This 'paracratering' backweathering decline with time is analogous to the paraglacial effect observed in rock slopes after deglaciation, but the relaxation time scale of 101 - 102 Myr compared to 10 kyr of the Milankovitch-controlled interglacial duration questions whether a paraglacial steady state is reached on Earth. The backweathering rates on the gullied pole-facing alcoves of the studied mid-latitude craters are much higher (˜2 - 60 times) than those on slopes with other azimuths and those in equatorial craters. The enhanced backweathering rates on gullied crater slopes may result from liquid water acting as a catalyst for backweathering. The decrease in backweathering rates over time might explain the similar size of gullies in young (craters, as alcove growth and sediment supply decrease to low background rates over time.

  20. Enviromental indicators in Amazonian Kichwa Communities from Ecuador for the ellaboration of a sustainable development strategy

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    Ruth Irene Arias Gutiérrez

    2015-02-01

    Full Text Available An environmental diagnosis is made in the Amazonian Kichwa region (Napo and Pastaza provinces, Ecuador for the ellaboration of a sustainable development strategy. The environmental indicators such as the number of cultivated plant species and their use. The use of forest and agricultural products were measured, as well. Qualitative and quantitative research methods, most appropriate for this study, were used. The quantitative methodology consisted in surveying to the residents, the leaders of the six communities and the heads of 64 households scattered around five rural parishes. The main results are collected in a strategic agenda that would boost the ecological sustainability. The communities employ a high number of species directly as food, and a fewer for medical, flavoring and cosmetic use. However, a single use of resources as raw materials is observed. With no the application of science and technology, there is not an orderly and efficient use of resources, which is achieved by establishing links with other universities research projects. It is necessary to replenish and enhance native renewable resources used by the communities, and add value and work on human capital formation for the protection of these resources. Local resources are not reasonably used with a focus on the protection of the environment and the extensive Amazonian biodiversity. There are high rates of illiteracy in the communities. That’s why it is important the development of bio-knowledge through public interventions, which will help sustain the national competitive advantage, based on its natural and biological richness, supported by the development of local production networks and technology generation. A proposed strategy for a sustainable agro-ecological community development was made.

  1. On the vertical distribution of smoke in the Amazonian atmosphere during the dry season

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    F. Marenco

    2016-02-01

    Full Text Available Lidar observations of smoke aerosols have been analysed from six flights of the Facility for Airborne Atmospheric Measurements BAe-146 research aircraft over Brazil during the biomass burning season (September 2012. A large aerosol optical depth (AOD was observed, typically ranging 0.4–0.9, along with a typical aerosol extinction coefficient of 100–400 Mm−1. The data highlight the persistent and widespread nature of the Amazonian haze, which had a consistent vertical structure, observed over a large distance ( ∼ 2200 km during a period of 14 days. Aerosols were found near the surface; but the larger aerosol load was typically found in elevated layers that extended from 1–1.5 to 4–6 km. The measurements have been compared to model predictions with the Met Office Unified Model (MetUM and the ECMWF-MACC model. The MetUM generally reproduced the vertical structure of the Amazonian haze observed with the lidar. The ECMWF-MACC model was also able to reproduce the general features of smoke plumes albeit with a small overestimation of the AOD. The models did not always capture localised features such as (i smoke plumes originating from individual fires, and (ii aerosols in the vicinity of clouds. In both these circumstances, peak extinction coefficients of the order of 1000–1500 Mm−1 and AODs as large as 1–1.8 were encountered, but these features were either underestimated or not captured in the model predictions. Smoke injection heights derived from the Global Fire Assimilation System (GFAS for the region are compatible with the general height of the aerosol layers.

  2. Adenomatous hyperplasia of the mucous glands in captive Archey's frogs (Leiopelma archeyi).

    Science.gov (United States)

    Shaw, S D; Berger, L; Harvey, C; Alley, M R; Bishop, P J; Speare, R

    2017-05-01

    To describe the gross and light microscopic characteristics of skin lesions observed on the ventral skin of captive Archey's frogs (Leiopelma archeyi) between 2000 and 2012, and to investigate their occurrence, possible aetiology and association with survival. Postmortem skin samples were obtained for histological evaluation from 37 frogs, with and without skin lesions, that died while in captivity at Auckland Zoo between 2000 and 2012. Four frogs with skin lesions were biopsied under general anaesthesia and samples used for both light and transmission electron microscopy. The records of 94 frogs held at the University of Otago and Auckland Zoo between 2000-2012 were reviewed, which included some frogs recently collected from the wild. Information about the occurrence of skin lesions, and mortality associated with skin lesions was collated. Grossly the skin lesions varied in appearance; most were circular, pale grey papules, which measured from located predominantly on ventral surfaces including trunk, thighs, lower legs and forearms, and gular region, but not on digits. The number ranged from single to multiple, often confluent lesions covering the entire ventral surface of the frog. Histologically the lesions consisted of enlarged proliferating mucous glands that expanded the dermis and elevated the epidermis. They were semi-organised, solid or occasionally cavitated acinar structures with central lumina which sometimes contained mucus. Nuclei showed moderate anisokaryosis and mitotic figures were uncommon. Transmission electron microscopy did not show any infectious agents. Between 2000 and 2012, skin lesions were recorded in 35/94 (37%) frogs. The size and location of skin lesions varied over time, with some resolving and sometimes reappearing. Skin lesions were not associated with an increased risk of death. The skin lesions had the gross and microscopic characteristics of adenomatous hyperplasia of the dermal mucous glands. The aetiology of this adenomatous

  3. An Analysis of Predator Selection to Affect Aposematic Coloration in a Poison Frog Species.

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    Corinna E Dreher

    Full Text Available Natural selection is widely noted to drive divergence of phenotypic traits. Predation pressure can facilitate morphological divergence, for example the evolution of both cryptic and conspicuous coloration in animals. In this context Dendrobatid frogs have been used to study evolutionary forces inducing diversity in protective coloration. The polytypic strawberry poison frog (Oophaga pumilio shows strong divergence in aposematic coloration among populations. To investigate whether predation pressure is important for color divergence among populations of O. pumilio we selected four mainland populations and two island populations from Costa Rica and Panama. Spectrometric measurements of body coloration were used to calculate color and brightness contrasts of frogs as an indicator of conspicuousness for the visual systems of several potential predators (avian, crab and snake and a conspecific observer. Additionally, we conducted experiments using clay model frogs of different coloration to investigate whether the local coloration of frogs is better protected than non-local color morphs, and if predator communities vary among populations. Overall predation risk differed strongly among populations and interestingly was higher on the two island populations. Imprints on clay models indicated that birds are the main predators while attacks of other predators were rare. Furthermore, clay models of local coloration were equally likely to be attacked as those of non-local coloration. Overall conspicuousness (and brightness contrast of local frogs was positively correlated with attack rates by birds across populations. Together with results from earlier studies we conclude that conspicuousness honestly indicates toxicity to avian predators. The different coloration patterns among populations of strawberry poison frogs in combination with behavior and toxicity might integrate into equally efficient anti-predator strategies depending on local predation and

  4. Biodiversity of frog haemoparasites from sub-tropical northern KwaZulu-Natal, South Africa

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    Edward C. Netherlands

    2015-04-01

    Full Text Available Since South Africa boasts a high biodiversity of frog species, a multispecies haemoparasite survey was conducted by screening the blood from 29 species and 436 individual frogs. Frogs were collected at three localities in sub-tropical KwaZulu-Natal, a hotspot for frog diversity. Twenty per cent of the frogs were infected with at least one of five groups of parasites recorded. Intraerythrocytic parasites comprising Hepatozoon, Dactylosoma, and viral or bacterial organisms, as well as extracellular parasites including trypanosomes and microfilarid nematodes were found. A significant difference (P < 0.01 in the prevalence of parasitaemia was found across species, those semi-aquatic species demonstrating the highest, followed by semi-terrestrial frog species. None of those species described as purely terrestrial and aquatic were infected. Hepatozoon and Trypanosoma species accounted for most of the infections, the former demonstrating significant differences in intensity of infection across species, families and habitat types (P = 0.028; P = 0.006; P = 0.007 respectively. Per locality, the first, the formally protected Ndumo Game Reserve, had the highest biodiversity of haemoparasite infections, with all five groups of parasites recorded. The other two sites, that is the area bordering the reserve and the Kwa Nyamazane Conservancy, had a lower diversity with no parasite infections recorded and only Hepatozoon species recorded respectively. Such findings could be ascribed to the anthropogenic impact on the latter two sites, the first by the rural village activities, and the second by the bordering commercial sugar cane agriculture. Future studies should include both morphological and molecular descriptions of the above parasites, as well as the identification of potential vectors, possibly clarifying the effects human activities may have on frog haemoparasite life cycles and as such their biodiversity.

  5. Convergent Substitutions in a Sodium Channel Suggest Multiple Origins of Toxin Resistance in Poison Frogs.

    Science.gov (United States)

    Tarvin, Rebecca D; Santos, Juan C; O'Connell, Lauren A; Zakon, Harold H; Cannatella, David C

    2016-04-01

    Complex phenotypes typically have a correspondingly multifaceted genetic component. However, the genotype-phenotype association between chemical defense and resistance is often simple: genetic changes in the binding site of a toxin alter how it affects its target. Some toxic organisms, such as poison frogs (Anura: Dendrobatidae), have defensive alkaloids that disrupt the function of ion channels, proteins that are crucial for nerve and muscle activity. Using protein-docking models, we predict that three major classes of poison frog alkaloids (histrionicotoxins, pumiliotoxins, and batrachotoxins) bind to similar sites in the highly conserved inner pore of the muscle voltage-gated sodium channel, Nav1.4. We predict that poison frogs are somewhat resistant to these compounds because they have six types of amino acid replacements in the Nav1.4 inner pore that are absent in all other frogs except for a distantly related alkaloid-defended frog from Madagascar, Mantella aurantiaca. Protein-docking models and comparative phylogenetics support the role of these replacements in alkaloid resistance. Taking into account the four independent origins of chemical defense in Dendrobatidae, phylogenetic patterns of the amino acid replacements suggest that 1) alkaloid resistance in Nav1.4 evolved independently at least seven times in these frogs, 2) variation in resistance-conferring replacements is likely a result of differences in alkaloid exposure across species, and 3) functional constraint shapes the evolution of the Nav1.4 inner pore. Our study is the first to demonstrate the genetic basis of autoresistance in frogs with alkaloid defenses. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Cytological maps of lampbrush chromosomes of European water frogs (Pelophylax esculentus complex) from the Eastern Ukraine

    Science.gov (United States)

    2013-01-01

    Background Hybridogenesis (hemiclonal inheritance) is a kind of clonal reproduction in which hybrids between parental species are reproduced by crossing with one of the parental species. European water frogs (Pelophylax esculentus complex) represent an appropriate model for studying interspecies hybridization, processes of hemiclonal inheritance and polyploidization. P. esculentus complex consists of two parental species, P. ridibundus (the lake frog) and P. lessonae (the pool frog), and their hybridogenetic hybrid – P. esculentus (the edible frog). Parental and hybrid frogs can reproduce syntopically and form hemiclonal population systems. For studying mechanisms underlying the maintenance of water frog population systems it is required to characterize the karyotypes transmitted in gametes of parental and different hybrid animals of both sexes. Results In order to obtain an instrument for characterization of oocyte karyotypes in hybrid female frogs, we constructed cytological maps of lampbrush chromosomes from oocytes of both parental species originating in Eastern Ukraine. We further identified certain molecular components of chromosomal marker structures and mapped coilin-rich spheres and granules, chromosome associated nucleoli and special loops accumulating splicing factors. We recorded the dissimilarities between P. ridibundus and P. lessonae lampbrush chromosomes in the length of orthologous chromosomes, number and location of marker structures and interstitial (TTAGGG)n-repeat sites as well as activity of nucleolus organizer. Satellite repeat RrS1 was mapped in centromere regions of lampbrush chromosomes of the both species. Additionally, we discovered transcripts of RrS1 repeat in oocytes of P. ridibundus and P. lessonae. Moreover, G-rich transcripts of telomere repeat were revealed in association with terminal regions of P. ridibundus and P. lessonae lampbrush chromosomes. Conclusions The constructed cytological maps of lampbrush chromosomes of P

  7. An Analysis of Predator Selection to Affect Aposematic Coloration in a Poison Frog Species.

    Science.gov (United States)

    Dreher, Corinna E; Cummings, Molly E; Pröhl, Heike

    2015-01-01

    Natural selection is widely noted to drive divergence of phenotypic traits. Predation pressure can facilitate morphological divergence, for example the evolution of both cryptic and conspicuous coloration in animals. In this context Dendrobatid frogs have been used to study evolutionary forces inducing diversity in protective coloration. The polytypic strawberry poison frog (Oophaga pumilio) shows strong divergence in aposematic coloration among populations. To investigate whether predation pressure is important for color divergence among populations of O. pumilio we selected four mainland populations and two island populations from Costa Rica and Panama. Spectrometric measurements of body coloration were used to calculate color and brightness contrasts of frogs as an indicator of conspicuousness for the visual systems of several potential predators (avian, crab and snake) and a conspecific observer. Additionally, we conducted experiments using clay model frogs of different coloration to investigate whether the local coloration of frogs is better protected than non-local color morphs, and if predator communities vary among populations. Overall predation risk differed strongly among populations and interestingly was higher on the two island populations. Imprints on clay models indicated that birds are the main predators while attacks of other predators were rare. Furthermore, clay models of local coloration were equally likely to be attacked as those of non-local coloration. Overall conspicuousness (and brightness contrast) of local frogs was positively correlated with attack rates by birds across populations. Together with results from earlier studies we conclude that conspicuousness honestly indicates toxicity to avian predators. The different coloration patterns among populations of strawberry poison frogs in combination with behavior and toxicity might integrate into equally efficient anti-predator strategies depending on local predation and other ecological

  8. Field hydration state varies among tropical frog species with different habitat use.

    Science.gov (United States)

    Tracy, Christopher R; Tixier, Thomas; Le Nöene, Camille; Christian, Keith A

    2014-01-01

    We have previously shown that ecological habit (e.g., arboreal, terrestrial, amphibious) correlates with thermoregulatory behaviors and water balance physiology among species of hylid frogs in northern Australia. We hypothesized that these frogs would be different with respect to their field hydration states because of the challenges associated with the different ecological habits. There are very few data on the hydration levels that frogs maintain in the field, and the existing data are from disparate species and locations and do not relate hydration state to habit or changes in seasonal water availability. We measured the hydration state of 15 species of frogs from tropical northern Australia to determine the influences of ecological habit and season on the hydration state that these frogs maintain. As predicted, frogs were significantly less hydrated in the dry season than they were in the wet season and showed significantly higher variation among individuals, suggesting that maintaining hydration is more challenging in the dry season. In the wet season, terrestrial species were significantly less hydrated than arboreal or amphibious species. During the dry season, amphibious species that sought refuge in cracking mud after the pond dried were significantly less hydrated than terrestrial or arboreal species. These data suggest that hydration behaviors and voluntary tolerance of dehydration vary with habitat use, even within closely related species in the same family or genus. Terrestrial and arboreal species might be expected to be the most vulnerable to changes in water availability, because they are somewhat removed from water sources, but the physiological characteristics of arboreal frogs that result in significant cutaneous resistance to water loss allow them to reduce the effects of their dehydrating microenvironment.

  9. Enzymatic regulation of glycogenolysis in a subarctic population of the wood frog: implications for extreme freeze tolerance.

    Directory of Open Access Journals (Sweden)

    M Clara F do Amaral

    Full Text Available The wood frog, Rana sylvatica, from Interior Alaska survives freezing at -16°C, a temperature 10-13°C below that tolerated by its southern conspecifics. We investigated the hepatic freezing response in this northern phenotype to determine if its profound freeze tolerance is associated with an enhanced glucosic cryoprotectant system. Alaskan frogs had a larger liver glycogen reserve that was mobilized faster during early freezing as compared to conspecifics from a cool-temperate region (southern Ohio, USA. In Alaskan frogs the rapid glucose production in the first hours of freezing was associated with a 7-fold increase in glycogen phosphorylase activity above unfrozen frog levels, and the activity of this enzyme was higher than that of frozen Ohioan frogs. Freezing of Ohioan frogs induced a more modest (4-fold increase in glycogen phosphorylase activity above unfrozen frog values. Relative to the Ohioan frogs, Alaskan frogs maintained a higher total protein kinase A activity throughout an experimental freezing/thawing time course, and this may have potentiated glycogenolysis during early freezing. We found populational variation in the activity and protein level of protein kinase A which suggested that the Alaskan population had a more efficient form of this enzyme. Alaskan frogs modulated their glycogenolytic response by decreasing the activity of glycogen phosphorylase after cryoprotectant mobilization was well under way, thereby conserving their hepatic glycogen reserve. Ohioan frogs, however, sustained high glycogen phosphorylase activity until early thawing and consumed nearly all their liver glycogen. These unique hepatic responses of Alaskan R. sylvatica likely contribute to this phenotype's exceptional freeze tolerance, which is necessary for their survival in a subarctic climate.

  10. Rangewide phylogeography of the western U.S. endemic frog Rana boylii (Ranidae): Implications for the conservation of frogs and rivers

    Science.gov (United States)

    A.J. Lind; H.B. Shaffer; P.Q. Spinks; G.M. Fellers

    2011-01-01

    Genetic data are increasingly being used in conservation planning for declining species. We sampled both the ecological and distributional limits of the foothill yellow-legged frog, Rana boylii to characterize mitochondrial DNA (mtDNA) variation in this declining, riverine amphibian. We evaluated 1525 base pairs (bp) of cytochrome b...

  11. Workplan for Catalyzing Collaboration with Amazonian Universities in the Large Scale Biosphere-Atmosphere Experiment in Amazonia (LBA)

    Science.gov (United States)

    Brown, I. Foster; Moreira, Adriana

    1997-01-01

    Success of the Large-Scale Biosphere-Atmospheric Experiment in Amazonia (LBA) program depends on several critical factors, the most important being the effective participation of Amazonian researchers and institutions. Without host-county counterparts, particularly in Amazonia, many important studies cannot he undertaken due either to lack of qualified persons or to legal constraints. No less important, the acceptance of the LBA program in Amazonia is also dependent on what LBA can do for improving the scientific expertise in Amazonia. Gaining the active investment of Amazonian scientists in a comprehensive research program is not a trivial task. Potential collaborators are few, particularly where much of the research was to be originally focused - the southern arc of Brazilian Amazonia. The mid-term goals of the LBA Committee on Training and Education are to increase the number of collaborators and to demonstrate that LBA will be of benefit to the region.

  12. Basic organization principles of the VOR: lessons from frogs.

    Science.gov (United States)

    Straka, H; Dieringer, N

    2004-07-01

    Locomotion is associated with a number of optical consequences that degrade visual information processing in the absence of appropriate compensatory movements. The resulting retinal image flow is counteracted by coordinated eye-head reflexes that are initiated by optokinetic and vestibular inputs. The contribution of the vestibulo-ocular reflex (VOR) for stabilizing retinal images is relatively small in amplitude in frogs but important in function by compensating for the non-linearities of the neck motor system. The spatial tuning of the VOR networks underlying the angular (AVOR) and linear (LVOR) with respect to canal and extraocular motor coordinates is organized in a common, canal-related reference frame. Thereby, the axes of head and eye rotation are aligned, principle and auxiliary VOR connections transform vestibular into motor signals and parallel AVOR and LVOR circuits mediate vergence and version signals separately. Comparison of these results with data from other vertebrates demonstrates a number of fundamental organization principles common to most vertebrates. However, the fewer degrees of behavioral freedom of frogs are reflected by the absence of, e.g. a functioning velocity storage network or of a fixation suppression of the VOR. In vitro experiments with the isolated brainstem and branches of N.VIII attached were used to study the putative transmitters of vestibular nerve afferent inputs, the postsynaptic receptor subtypes of second-order vestibular neurons and their dynamic response properties. Evidence is presented that suggests that afferent vestibular nerve fibers with different dynamic response properties activate different subtypes of glutamate receptors. The convergence pattern of monosynaptic afferent nerve inputs from different labyrinthine organs onto second-order vestibular neurons is remarkably specific. As a rule, second-order vestibular neurons receive converging afferent nerve inputs from one semicircular canal and from a specific

  13. Evidence for the control of the geochemistry of Amazonian floodplain sediments by stratification of suspended sediments in the Amazon

    OpenAIRE

    Roddaz, M.; Viers, J.; Moreira Turcq, Patricia; Blondel, C.; Sondag, Francis; Guyot, Jean-Loup; Moreira, L.

    2014-01-01

    Holocene and historical Amazonian floodplain deposits collected from two cores of the "Varzea do Curuai" flooded area (Brazil) were analysed for major and trace element geochemistry as well as Nd-Sr isotopic compositions (21 samples). The TA11 and TA14 cores (110 cm and 270 cm in depth, respectively) were collected at different locations in the Varzea, near a channel inlet connecting the Amazon River to the Varzea and at the centre of the Varzea, respectively. The two cores represent records ...

  14. Two new species in the Matelea stenopetala complex (Apocynaceae, Asclepiadoideae) from the Guiana Shield and Amazonian Brazil

    Science.gov (United States)

    Krings, Alexander; Morillo, Gilberto

    2012-01-01

    Abstract Two new species in the Matelea stenopetala complex (Apocynaceae, Asclepiadoideae) are described from the Guiana Shield and Amazonian Brazil: Matelea brevistipitata Krings & Morillo, sp. nov. and Matelea trichopedicellataKrings & Morillo, sp. nov. The new species belong to a small group of adaxially-pubescent-flowered taxa within the complex, including Matelea hildegardiana and Matelea pakaraimensis. The new species are described and a dichotomous key is provided. PMID:23233816

  15. Prevalence of Spirometra mansoni in dogs, cats, and frogs and its medical relevance in Guangzhou, China.

    Science.gov (United States)

    Hong, Qing; Feng, Jieping; Liu, Haijuan; Li, Xiaomin; Gong, Lirong; Yang, Zhen; Yang, Weiming; Liang, Xiongfa; Zheng, Rujiang; Cui, Zhicai; Wang, Weiliang; Chen, Daixiong

    2016-12-01

    Sparganosis is an important parasitic disease in Guangzhou and is mainly acquired through the consumption of frog meat or contact with fresh frogs infected by larval stages (spargana) of the tapeworm species Spirometra mansoni. In this study, the prevalence of intestinal S. mansoni infections (with adult parasites) in dogs and cats and of extraintestinal S. mansoni infections (with spargana) in frogs was assessed. In addition, a questionnaire survey was carried out among residents in Guangzhou City in order to evaluate their awareness about the medical and epidemiological relevance of Spirometra and sparganosis. In total, the feces of 229 dogs and 116 cats were examined for eggs, and 1949 frogs were examined for spargana. Sixty-three dogs (27.5%) and 47 cats (40.5%) had eggs in their feces. Two hundred and sixteen out of 416 wild Rana tigrina rugulosa Wiegmann frogs examined were sparganum-positive, with an infection rate of 51.9%, while the infection rate in Rana limnocharis Boie was 35.1% (13/37). None of the tested farmed frogs (including R. tigrina rugulosa and Rana catesbeiana) was positive (0/1382). Analysis of the questionnaire revealed the following results: (1) about 41.0% of residents in Guangzhou had some knowledge of sparganosis or sparganum infection, and information in TV programs was the most important way that residents learned about sparganosis. (2) About 59.9% of the residents ate frog meat. Eating the meat, viscera, or blood of animals, e.g., frogs, snakes, pigs, chicken, mice, and birds, in an improper way might be the main means by which residents acquire the infection. (3) The risk of sparganum infection was higher in males than in females. A high sparganum infection rate was observed in the wild frogs sold in agricultural product markets in Guangzhou. The infection was also serious in cats and dogs in Guangdong Province. With lifestyles and eating habits resulting in sparganum infection, it is necessary to focus on market management and

  16. Conceptions and practices of an integrative treatment for substance use disorders involving Amazonian medicine: traditional healers' perspectives.

    Science.gov (United States)

    Berlowitz, Ilana; Ghasarian, Christian; Walt, Heinrich; Mendive, Fernando; Alvarado, Vanessa; Martin-Soelch, Chantal

    2017-12-18

    The harmful use of psychoactive substances represents one of today's largest public health problems. Yet, in spite of its global relevance, current treatment for substance use disorders (SUDs) is still not entirely successful. The purpose of this study was to investigate alternative treatments and conceptions from traditional Amazonian medicine adapted to SUDs. We conducted semi-structured interviews with 13 practicing experts at a well-established addiction treatment center in the Peruvian Amazon and performed qualitative content analysis on the collected data. Main categories were deductively defined and corresponding subcategories inductively developed. Our findings revealed characteristic features and consequences, causes and antecedents, and treatment methods of SUDs as the main categories. Overall, concepts of disease etiology bore resemblance with contemporary biopsychosocial models of SUDs. The Amazonian therapeutic means however differed markedly from current Western ones. The main methods involved dietary retreats, healing ceremonies, and purging rituals. The integral application of Amazonian methods, as well as their traditional implementation according to prescribed ritual protocols, were emphasized by the experts as crucial for efficacy and safety of treatment delivery. We suggest further scientific attention to these therapies, including clinical studies, for which our results provide conceptual underpinnings. Findings from this research expand the cross-cultural understanding of SUDs and, in the long run, may enhance its treatment options.

  17. Isotopes as validation tools for predictions of the impact of Amazonian deforestation on climate and regional hydrology

    International Nuclear Information System (INIS)

    Henderson-Sellers, A.; Chambers, S.; McGuffie, K.

    2002-01-01

    Isotopic analysis and modelling of the Amazon Basin have both been reported for about thirty years. Isotopic data have been used to explain important characteristics of Amazonian hydrologic cycling by means of simple models. To date there has been no attempt to use isotopic data to evaluate global climate models employed to predict the possible impacts of Amazonian deforestation. This paper reviews the history of isotopic analysis and simulations of deforestation in the Amazon and initiates isotopic evaluation of GCMs. It is shown that one widely reported simulation set gives seasonal transpiration and re-evaporated canopy interception budgets different from those derived from isotopic analysis. It is found that temporal changes (1965 to 1990) in wet season deuterium excess differences between Belem and Manaus are consistent with GCM results only if there has been a relative increase in evaporation from non-fractionating water sources over this period. We propose synergistic future interactions among the climate/hydrological modelling and isotopic analysis communities in order to improve confidence in simulations of Amazonian deforestation. (author)

  18. Comparison of metal bioavailability in frogs from urban and rural sites of Western Ukraine.

    Science.gov (United States)

    Stolyar, O B; Loumbourdis, N S; Falfushinska, H I; Romanchuk, L D

    2008-01-01

    The seasonal and spatial fluctuations of heavy metals in the liver of the frog Rana ridibunda from a river in Western Ukraine were investigated. Liver weight was seen to increase from spring to summer/autumn, most probably as a result of accumulation of metabolites, especially fat and glycogen. The concentrations of the metals found in the liver of the frog was in the order: Fe>Cu approximately Zn>Mn>Cd. For most metals, the highest concentration was recorded in the frogs inhabiting the urban site. The highest level of Cu in the liver was observed in the spring, in the agricultural site, while the highest level of other metals was observed in the summer. The most probable explanation for the high concentration of Cu in the rural site was that in this wetland there were discharge effluents from fungicides with Cu in their formula. Compared to other metals, the bioavailability of Cu was approximately 1000 times higher. The high concentration of Fe rather reflects its fluctuation in the water. Despite its very low concentration in the water (below the limit of detection), Cd was detected in the liver of frogs inhabiting both sites. This is an indication that tissues accumulate Cd, despite the very low concentration detected in the water. This may be an indication of intermittent exposure of frogs to Cd and possibly of other heavy metals.

  19. Urea loading enhances freezing survival and postfreeze recovery in a terrestrially hibernating frog.

    Science.gov (United States)

    Costanzo, Jon P; Lee, Richard E

    2008-09-01

    We tested the hypothesis that urea, an osmolyte accumulated early in hibernation, functions as a cryoprotectant in the freeze-tolerant wood frog, Rana sylvatica. Relative to saline-treated, normouremic (10 micromol ml(-1)) frogs, individuals rendered hyperuremic (70 micromol ml(-1)) by administration of an aqueous urea solution exhibited significantly higher survival (100% versus 64%) following freezing at -4 degrees C, a potentially lethal temperature. Hyperuremic frogs also had lower plasma levels of intracellular proteins (lactate dehydrogenase, creatine kinase, hemoglobin), which presumably escaped from damaged cells, and more quickly recovered neurobehavioral functions following thawing. Experimental freezing-thawing did not alter tissue urea concentrations, but did elevate glucose levels in the blood and organs of all frogs. When measured 24 h after thawing commenced, glucose concentrations were markedly higher in urea-loaded frogs as compared to saline-treated ones, possibly because elevated urea retarded glucose clearance. Like other low-molecular-mass cryoprotectants, urea colligatively reduces both the amount of ice forming within the body and the osmotic dehydration of cells. In addition, by virtue of certain non-colligative properties, it may bestow additional protection from freeze-thaw damage not afforded by glucose.

  20. Composition and Functional Specialists of the Gut Microbiota of Frogs Reflect Habitat Differences and Agricultural Activity.

    Science.gov (United States)

    Huang, Bing-Hong; Chang, Chun-Wen; Huang, Chih-Wei; Gao, Jian; Liao, Pei-Chun

    2017-01-01

    The physiological impact of agricultural pollution, habitat disturbance, and food source variability on amphibian remains poorly understood. By comparing the composition and predicted functions of gut microbiota of two frog species from forest and farmland, we quantified the effects of the exogenous environment and endogenous filters on gut microbiota and the corresponding functions. However, compositional differences of the gut microbiota between the frog species were not detected, even when removing roughly 80-88% of the confounding effect produced by common and shared bacteria (i.e., generalists) and those taxa deemed too rare. The habitat effect accounted for 14.1% of the compositional difference of gut microbial specialists, but host and host × habitat effects were not significant. Similar trends of a significant habitat effect, at an even higher level (26.0%), for the physiological and metabolic functions of gut microbiota was predicted. A very obvious skewing of the relative abundance of functional groups toward farmland habitats reflects the highly diverse bacterial functions of farmland frogs, in particular related to pathogenic disease and pesticide degradation, which may be indication of poor adaptation or strong selective pressure against disease. These patterns reflect the impacts of agricultural activities on frogs and how such stresses may be applied in an unequal manner for different frog species.

  1. Legacy of road salt: Apparent positive larval effects counteracted by negative postmetamorphic effects in wood frogs.

    Science.gov (United States)

    Dananay, Kacey L; Krynak, Katherine L; Krynak, Timothy J; Benard, Michael F

    2015-10-01

    Road salt runoff has potentially large effects on wetland communities, but is typically investigated in short-term laboratory trials. The authors investigated effects of road salt contamination on wood frogs (Rana sylvatica) by combining a field survey with 2 separate experiments. The field survey tested whether wood frog larval traits were associated with road salt contamination in natural wetlands. As conductivity increased, wood frog larvae were less abundant, but those found were larger. In the first experiment of the present study, the authors raised larvae in outdoor artificial ponds under 4 salt concentrations and measured larval vital rates, algal biomass, and zooplankton abundance. Salt significantly increased larval growth, algal biomass, and decreased zooplankton abundance. In the second experiment, the authors raised larvae to metamorphosis in the presence and absence of salt contamination and followed resulting juvenile frogs in terrestrial pens at high and low densities. Exposure to road salt as larvae caused juvenile frogs to have greater mortality in low-density terrestrial environments, possibly because of altered energy allocation, changes in behavior, or reduced immune defenses. The present study suggests that low concentrations of road salt can have positive effects on larval growth yet negative effects on juvenile survival. These results emphasize the importance of testing for effects of contaminants acting through food webs and across multiple life stages as well as the potential for population-level consequences in natural environments. © 2015 SETAC.

  2. Composition and Functional Specialists of the Gut Microbiota of Frogs Reflect Habitat Differences and Agricultural Activity

    Directory of Open Access Journals (Sweden)

    Bing-Hong Huang

    2018-01-01

    Full Text Available The physiological impact of agricultural pollution, habitat disturbance, and food source variability on amphibian remains poorly understood. By comparing the composition and predicted functions of gut microbiota of two frog species from forest and farmland, we quantified the effects of the exogenous environment and endogenous filters on gut microbiota and the corresponding functions. However, compositional differences of the gut microbiota between the frog species were not detected, even when removing roughly 80–88% of the confounding effect produced by common and shared bacteria (i.e., generalists and those taxa deemed too rare. The habitat effect accounted for 14.1% of the compositional difference of gut microbial specialists, but host and host × habitat effects were not significant. Similar trends of a significant habitat effect, at an even higher level (26.0%, for the physiological and metabolic functions of gut microbiota was predicted. A very obvious skewing of the relative abundance of functional groups toward farmland habitats reflects the highly diverse bacterial functions of farmland frogs, in particular related to pathogenic disease and pesticide degradation, which may be indication of poor adaptation or strong selective pressure against disease. These patterns reflect the impacts of agricultural activities on frogs and how such stresses may be applied in an unequal manner for different frog species.

  3. Factors influencing survival and mark retention in postmetamorphic boreal chorus frogs

    Science.gov (United States)

    Swanson, Jennifer E; Bailey, Larissa L.; Muths, Erin L.; Funk, W. Chris

    2013-01-01

    The ability to track individual animals is crucial in many field studies and often requires applying marks to captured individuals. Toe clipping has historically been a standard marking method for wild amphibian populations, but more recent marking methods include visual implant elastomer and photo identification. Unfortunately, few studies have investigated the influence and effectiveness of marking methods for recently metamorphosed individuals and as a result little is known about this life-history phase for most amphibians. Our focus was to explore survival probabilities, mark retention, and mark migration in postmetamorphic Boreal Chorus Frogs (Psuedacris maculata) in a laboratory setting. One hundred forty-seven individuals were assigned randomly to two treatment groups or a control group. Frogs in the first treatment group were marked with visual implant elastomer, while frogs in the second treatment group were toe clipped. Growth and mortality were recorded for one year and resulting data were analyzed using known-fate models in Program MARK. Model selection results suggested that survival probabilities of frogs varied with time and showed some variation among marking treatments. We found that frogs with multiple toes clipped on the same foot had lower survival probabilities than individuals in other treatments, but individuals can be marked by clipping a single toe on two different feet without any mark loss or negative survival effects. Individuals treated with visual implant elastomer had a mark migration rate of 4% and mark loss rate of 6%, and also showed very little negative survival impacts relative to control individuals.

  4. Propulsive efficiency of frog swimming with different feet and swimming patterns.

    Science.gov (United States)

    Jizhuang, Fan; Wei, Zhang; Bowen, Yuan; Gangfeng, Liu

    2017-04-15

    Aquatic and terrestrial animals have different swimming performances and mechanical efficiencies based on their different swimming methods. To explore propulsion in swimming frogs, this study calculated mechanical efficiencies based on data describing aquatic and terrestrial webbed-foot shapes and swimming patterns. First, a simplified frog model and dynamic equation were established, and hydrodynamic forces on the foot were computed according to computational fluid dynamic calculations. Then, a two-link mechanism was used to stand in for the diverse and complicated hind legs found in different frog species, in order to simplify the input work calculation. Joint torques were derived based on the virtual work principle to compute the efficiency of foot propulsion. Finally, two feet and swimming patterns were combined to compute propulsive efficiency. The aquatic frog demonstrated a propulsive efficiency (43.11%) between those of drag-based and lift-based propulsions, while the terrestrial frog efficiency (29.58%) fell within the range of drag-based propulsion. The results illustrate the main factor of swimming patterns for swimming performance and efficiency. © 2017. Published by The Company of Biologists Ltd.

  5. Propulsive efficiency of frog swimming with different feet and swimming patterns

    Directory of Open Access Journals (Sweden)

    Fan Jizhuang

    2017-04-01

    Full Text Available Aquatic and terrestrial animals have different swimming performances and mechanical efficiencies based on their different swimming methods. To explore propulsion in swimming frogs, this study calculated mechanical efficiencies based on data describing aquatic and terrestrial webbed-foot shapes and swimming patterns. First, a simplified frog model and dynamic equation were established, and hydrodynamic forces on the foot were computed according to computational fluid dynamic calculations. Then, a two-link mechanism was used to stand in for the diverse and complicated hind legs found in different frog species, in order to simplify the input work calculation. Joint torques were derived based on the virtual work principle to compute the efficiency of foot propulsion. Finally, two feet and swimming patterns were combined to compute propulsive efficiency. The aquatic frog demonstrated a propulsive efficiency (43.11% between those of drag-based and lift-based propulsions, while the terrestrial frog efficiency (29.58% fell within the range of drag-based propulsion. The results illustrate the main factor of swimming patterns for swimming performance and efficiency.

  6. Citizen Science Program Shows Urban Areas Have Lower Occurrence of Frog Species, but Not Accelerated Declines.

    Science.gov (United States)

    Westgate, Martin J; Scheele, Ben C; Ikin, Karen; Hoefer, Anke Maria; Beaty, R Matthew; Evans, Murray; Osborne, Will; Hunter, David; Rayner, Laura; Driscoll, Don A

    2015-01-01

    Understanding the influence of landscape change on animal populations is critical to inform biodiversity conservation efforts. A particularly important goal is to understand how urban density affects the persistence of animal populations through time, and how these impacts can be mediated by habitat provision; but data on this question are limited for some taxa. Here, we use data from a citizen science monitoring program to investigate the effect of urbanization on patterns of frog species richness and occurrence over 13 years. Sites surrounded by a high proportion of bare ground (a proxy for urbanization) had consistently lower frog occurrence, but we found no evidence that declines were restricted to urban areas. Instead, several frog species showed declines in rural wetlands with low-quality habitat. Our analysis shows that urban wetlands had low but stable species richness; but also that population trajectories are strongly influenced by vegetation provision in both the riparian zone and the wider landscape. Future increases in the extent of urban environments in our study area are likely to negatively impact populations of several frog species. However, existing urban areas are unlikely to lose further frog species in the medium term. We recommend that landscape planning and management focus on the conservation and restoration of rural wetlands to arrest current declines, and the revegetation of urban wetlands to facilitate the re-expansion of urban-sensitive species.

  7. Lead concentrations in bullfrog Rana catesbeiana and green frog R. clamitans tadpoles inhabiting highway drainages

    Science.gov (United States)

    Birdsall, C.W.; Grue, C.E.; Anderson, A.

    1986-01-01

    Lead concentrations were determined in sediment and tadpoles of bullfrogs Rana catesbeiana and green frogs R. clamitans from drainages along highways with different daily average traffic volumes (range, 4272 to I08,800 vehicles day-I) and from ponds >0.4 km from the nearest highway. Lead concentrations (mg kg--I dry weight) in sediment (7-8 to 940) were usually greater (4-5 times) than those in the tadpoles (bullfrog, 0,07 to 270; green frog, 0,90 to 240 mg kg-I). Lead concentrations in sediment (r =0.63) and in both species of tadpoles (bullfrog, r = 0.69; green frog, r = 0.57) were positively correlated with average daily traffic volume. Lead concentrations in both species of tadpoles (bullfrog, r = (). 76: green frog, r = 0.75) were also positively correlated with lead concentrations in sediment. At sites where both bullfrog and green frog tadpoles were collected. lead concentrations in the two species were closely related (r = 0.84). Lead concentrations in tadpoles living near highways may contribute to the elevated lead levels reported in wildlife that are potential tadpole predators. Dietary lead concentrations similar to those in our tadpoles have been associated with physiological and reproductive effects in some species of birds and mammals. However, additional data are needed to determine the hazards to predators of lead concentrations in tadpoles.

  8. Citizen Science Program Shows Urban Areas Have Lower Occurrence of Frog Species, but Not Accelerated Declines.

    Directory of Open Access Journals (Sweden)

    Martin J Westgate

    Full Text Available Understanding the influence of landscape change on animal populations is critical to inform biodiversity conservation efforts. A particularly important goal is to understand how urban density affects the persistence of animal populations through time, and how these impacts can be mediated by habitat provision; but data on this question are limited for some taxa. Here, we use data from a citizen science monitoring program to investigate the effect of urbanization on patterns of frog species richness and occurrence over 13 years. Sites surrounded by a high proportion of bare ground (a proxy for urbanization had consistently lower frog occurrence, but we found no evidence that declines were restricted to urban areas. Instead, several frog species showed declines in rural wetlands with low-quality habitat. Our analysis shows that urban wetlands had low but stable species richness; but also that population trajectories are strongly influenced by vegetation provision in both the riparian zone and the wider landscape. Future increases in the extent of urban environments in our study area are likely to negatively impact populations of several frog species. However, existing urban areas are unlikely to lose further frog species in the medium term. We recommend that landscape planning and management focus on the conservation and restoration of rural wetlands to arrest current declines, and the revegetation of urban wetlands to facilitate the re-expansion of urban-sensitive species.

  9. Chemical camouflage--a frog's strategy to co-exist with aggressive ants.

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    Mark-Oliver Rödel

    Full Text Available Whereas interspecific associations receive considerable attention in evolutionary, behavioural and ecological literature, the proximate bases for these associations are usually unknown. This in particular applies to associations between vertebrates with invertebrates. The West-African savanna frog Phrynomantis microps lives in the underground nest of ponerine ants (Paltothyreus tarsatus. The ants usually react highly aggressively when disturbed by fiercely stinging, but the frog is not attacked and lives unharmed among the ants. Herein we examined the proximate mechanisms for this unusual association. Experiments with termites and mealworms covered with the skin secretion of the frog revealed that specific chemical compounds seem to prevent the ants from stinging. By HPLC-fractionation of an aqueous solution of the frogs' skin secretion, two peptides of 1,029 and 1,143 Da were isolated and found to inhibit the aggressive behaviour of the ants. By de novo sequencing using tandem mass spectrometry, the amino acid sequence of both peptides consisting of a chain of 9 and 11 residues, respectively, was elucidated. Both peptides were synthesized and tested, and exhibited the same inhibitory properties as the original frog secretions. These novel peptides most likely act as an appeasement allomone and may serve as models for taming insect aggression.

  10. Asplenium bird’s nest ferns in rainforest canopies are climate-contingent refuges for frogs

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    Brett R. Scheffers

    2014-12-01

    Full Text Available Epiphytes are important for canopy dwelling organisms because they provide a cool and moist microhabitat in the relatively hot and dry canopy. Here we examine whether epiphytic Asplenium ferns act as important habitats for arboreal frogs. We conducted extensive fern and habitat surveys for frogs in the Philippines, and complimented these surveys with roaming day and night canopy surveys to identify the full extent of habitat use across the vertical strata. We artificially dried ferns of various sizes to identify relationships between water and temperature buffering. Ferns are the preferred diurnal microhabitat and breeding habitat for arboreal frogs. A strong positive relationship exists between fern size and frog usage and abundance. Our drying experiments show that large ferns buffer maximum temperatures and reduce variability in temperatures, and buffering is directly linked to their hydration. Frogs are likely using large ferns for their moist, cool, environments for breeding and daytime retreat, which supports the buffered microhabitat hypothesis—these plants promote species coexistence through habitat creation and amelioration of physical stress. However, drying experiments suggest that this buffering is contingent on regular rainfall. Altered rainfall regimes could lead to the unexpected loss of the functional capacity of these important fern habitats. Keywords: Climate change, Functionality, Microhabitat, Refuge, Ectotherm, Precipitation

  11. 76 FR 55413 - Proposed Safe Harbor Agreement for California Red-legged Frog, California Tiger Salamander, Smith...

    Science.gov (United States)

    2011-09-07

    ...] Proposed Safe Harbor Agreement for California Red-legged Frog, California Tiger Salamander, Smith's Blue...-legged frog (Rana draytonii) and California tiger salamander (Ambystoma californiense) and federally..., California tiger salamander, Smith's blue butterfly, and Yadon's piperia on the property subject to the...

  12. Inverse Effects on Growth and Development Rates by Means of Endocrine Disruptors in African Clawed Frog Tadpoles ("Xenopus Laevis")

    Science.gov (United States)

    Hackney, Zachary Carl

    2007-01-01

    Previous work on fish, frogs, and salamanders, showed the ability for estrogen (EE2) and anthropogenic endocrine disruptors to skew sex ratios and cause hermaphrodism. This study addressed the effects of estrogens on growth and development rates of African clawed frog tadpoles ("Xenopus laevis") during their gender determination stages. The…

  13. Experimental transmission of Hepatozoon clamatae (Apicomplexa: Adeleida) to the wood frog, Rana sylvatica, and to the mosquito Culex pipiens.

    Science.gov (United States)

    Harkness, Lisa M; Drohan, Ashley E; Dickson, Cory M; Smith, Todd G

    2010-04-01

    Hepatozoon clamatae naturally infects the erythrocytes of green frogs (Rana clamitans), bullfrogs (Rana catesbeiana), and northern leopard frogs (Rana pipiens) in northeastern North America and uses the mosquito Culex territans as a definitive host. In this study, we show that the wood frog, Rana sylvatica, supports merogonic development, but not gamogonic development, of this protozoan parasite, and that the mosquito Culex pipiens serves as an experimental definitive host for sporogonic development. Two wood frogs were each force-fed Cx. territans, containing oocysts of H. clamatae in their Malpighian tubules, which had fed on blood of infected green frogs 30 days previously. Free merozoites were observed in 1 wood frog 35 days after inoculation, but intraerythrocytic gamonts were not observed. Fifteen Cx. pipiens were fed on a mixture of infected frog blood and physiological saline. Thirty days after blood feeding, 2 mosquitoes were infected with oocysts of H. clamatae, whereas the other 13 mosquitoes either were negative for infection or had died. The observed absence of gamogonic development of this parasite in wood frogs are discussed in light of previous records of host specificity of Hepatozoon species for their anuran hosts, and the importance of Cx. pipiens as an additional definitive host for H. clamatae.

  14. Diet of introduced bullfrogs (Rana catesbeiana): Predation on and diet overlap with native frogs on Daishan Island, China

    Science.gov (United States)

    Wu, Zhengjun; Li, Y.; Wang, Y.; Adams, Michael J.

    2005-01-01

    We examined diet of introduced Bullfrogs (Rana catesbeiana) and three native frog species (Rana limnocharis, Rana nigromaculata, and Bufo bufo gargarizans) co-occurring at a group of ponds on Daishan Island, east of China, to gain insight into the nature of potential interactions between Bullfrogs and native frog species. For postmetamorphic Bullfrogs, aquatic prey items dominated volumetrically. Prey size, diet volume and volumetric percentage of native frogs in diet increased with Bullfrog body size. The number and volumetric percentage of native frogs in the diet were not different for female and male Bullfrogs, and both were higher for adults than for juveniles. Diet overlap between males and juveniles was higher than that between males and females and between females and juveniles. Diet overlap with each native frog species of male Bullfrogs was lower than that of female Bullfrogs and juvenile Bullfrogs. We did not exam effects of Bullfrogs on native frogs but our results suggest that the primary threat posed by juvenile Bullfrogs to native frogs on Daishan Island is competition for food, whereas the primary threat posed by male Bullfrogs is direct predation. Female Bullfrogs may threaten native frogs by both competition and predation. These differences among Bullfrog groups may be attributed to differences in body size and microhabitat use.

  15. Viability of Vibrio cholerae 01 on frog legs under frozen and refrigerated conditions and low dose radiation treatment

    International Nuclear Information System (INIS)

    Sang, F.C.; Hugh-Jones, M.E.; Hagstad, H.V.

    1987-01-01

    Frog legs were contaminated with Vibrio cholerae 01, Inaba serotype, EITor biotype. The organism remained viable for more than 28 and 2 d when stored at -20°C and 4°C, respectively. Exposure to a multicuries 60 Cobalt source of 50 and 100 kilorads eliminated V. cholerae from both the frozen and fresh frog legs

  16. FROG ASSEMBLAGE ASSOCIATED WITH BROMELIADS IN A SANDY COASTAL PLAIN IN THE STATE OF ESPÍRITO SANTO, SOUTHEASTERN BRAZIL

    Directory of Open Access Journals (Sweden)

    MARCIO MARQUES MAGESKI

    Full Text Available ABSTRACT Amphibians may use bromeliads for reproduction (i.e., bromeligenous species or only for refuge and foraging (i.e., bromelicolous species. The partition of bromeliad resources is essential to maintain the coexistence of the associated assemblages. We sampled 913 bromeliads in a sandy coastal plain (i.e., restinga habitat in southeastern Brazil and found 234 frogs belonging to seven species. One of the frog species was bromeligenous and the other six were facultative bromelicolous. The bromeliads of the genus Aechmea were the most frequently used by frogs. The low degree of frog occupancy of bromeliads (26% suggests habitat segregation. Our study highlights the importance of maintenance of bromeliad species for conservation of the associated frog assemblages.

  17. A success model and implementation on examining teacher’s attitude in using frog virtual learning environment

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    Wan Rozaini Sheik Osman

    2017-12-01

    Full Text Available The Frog Virtual Learning Environment (Frog VLE together with school administrators, teachers, students and parents has formed the concept of a virtual community within the school environment. The research uses a qualitative approach that involves interviewing four selected teachers in a primary school located in the district of Baling/ Sik, Kedah. The study employs a structured questionnaire as an interview protocol instrument. The questionnaires were also distributed to sixteen other teachers to compare the responses. The findings showed that teachers were using Frog VLE application and it helps in teaching and learning. Frog VLE also motivates teachers to teach better. However, not all teachers are comfortable using it because there are many obstacles and constraints that teachers face when applying them. The analysis of result from the teacher’s attitude indicated that there was an important relationship between the teacher’s basic knowledge of ICT and the skills in accessing the Frog VLE.

  18. Mercury bioaccumulation in wood frogs developing in seasonal pools

    Science.gov (United States)

    Loftin, Cynthia S.; Calhoun, Aram J.K.; Nelson, Sarah J.; Elskus, Adria; Simon, Kevin S.

    2012-01-01

    Seasonal woodland pools contribute significant biomass to terrestrial ecosystems through production of pool-breeding amphibians. The movement of amphibian metamorphs potentially transports toxins bioaccumulated during larval development in the natal pool into the surrounding terrestrial environment. We documented total mercury (THg) in seasonal woodland pool water, sediment, litter, and Lithobates sylvaticus LeConte (Wood Frog) in Acadia National Park, ME. THg concentrations in pool water varied over the study season, increasing during April—June and remaining high in 2 of 4 pools upon October refill. Water in pools surrounded by softwoods had lower pH, greater dissolved organic carbon, and greater THg concentrations than pools surrounded by hardwoods, with seasonal patterns in sediment THg but not litter THg. THg increased rapidly from near or below detection in 1–2 week old embryos (<0.2 ng; 0–0.49 ppb wet weight) to 17.1–54.2 ppb in tadpoles within 6 weeks; 7.2–42.0% of THg was methyl Hg in tadpoles near metamorphosis. Metamorphs emigrating from seasonal pools may transfer mercury into terrestrial food webs.

  19. Birds and frogs selected papers, 1990-2014

    CERN Document Server

    Dyson, Freeman J

    2015-01-01

    This book is a sequel to the volume of selected papers of Dyson up to 1990 that was published by the American Mathematical Society in 1996. The present edition comprises a collection of the most interesting writings of Freeman Dyson, all personally selected by the author, from the period 1990–2014. The five sections start off with an Introduction, followed by Talks about Science, Memoirs, Politics and History, and some Technical Papers. The most noteworthy is a lecture entitled Birds and Frogs to the American Mathematical Society that describes two kinds of mathematicians with examples from real life. Other invaluable contributions include an important tribute to C. N. Yang written for his retirement banquet at Stony Brook University, as well as a historical account of the Operational Research at RAF Bomber Command in World War II provocatively titled A Failure of Intelligence. The final section carries the open-ended question of whether any conceivable experiment could detect single gravitons to provide d...

  20. Environmental constraints and call evolution in torrent-dwelling frogs.

    Science.gov (United States)

    Goutte, Sandra; Dubois, Alain; Howard, Samuel D; Marquez, Rafael; Rowley, Jodi J L; Dehling, J Maximilian; Grandcolas, Philippe; Rongchuan, Xiong; Legendre, Frédéric

    2016-04-01

    Although acoustic signals are important for communication in many taxa, signal propagation is affected by environmental properties. Strong environmental constraints should drive call evolution, favoring signals with greater transmission distance and content integrity in a given calling habitat. Yet, few empirical studies have verified this prediction, possibly due to a shortcoming in habitat characterization, which is often too broad. Here we assess the potential impact of environmental constraints on the evolution of advertisement call in four groups of torrent-dwelling frogs in the family Ranidae. We reconstruct the evolution of calling site preferences, both broadly categorized and at a finer scale, onto a phylogenetic tree for 148 species with five markers (∼3600 bp). We test models of evolution for six call traits for 79 species with regard to the reconstructed history of calling site preferences and estimate their ancestral states. We find that in spite of existing morphological constraints, vocalizations of torrent-dwelling species are most probably constrained by the acoustic specificities of torrent habitats and particularly their high level of ambient noise. We also show that a fine-scale characterization of calling sites allows a better perception of the impact of environmental constraints on call evolution. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.