Differing long term trends for two common amphibian species (Bufo bufo and Rana temporaria in alpine landscapes of Salzburg, Austria.

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Martin Kyek

Full Text Available This study focuses on the population trends of two widespread European anuran species: the common toad (Bufo bufo and the common frog (Rana temporaria. The basis of this study is data gathered over two decades of amphibian fencing alongside roads in the Austrian state of Salzburg. Different statistical approaches were used to analyse the data. Overall average increase or decrease of each species was estimated by calculating a simple average locality index. In addition the statistical software TRIM was used to verify these trends as well as to categorize the data based on the geographic location of each migration site. The results show differing overall trends for the two species: the common toad being stable and the common frog showing a substantial decline over the last two decades. Further analyses based on geographic categorization reveal the strongest decrease in the alpine range of the species. Drainage and agricultural intensification are still ongoing problems within alpine areas, not only in Salzburg. Particularly in respect to micro-climate and the availability of spawning places these changes appear to have a greater impact on the habitats of the common frog than the common toad. Therefore we consider habitat destruction to be the main potential reason behind this dramatic decline. We also conclude that the substantial loss of biomass of a widespread species such as the common frog must have a severe, and often overlooked, ecological impact.

How fast do amphibians disperse? Introductions, distribution and dispersal of the common frog Rana temporaria and the common toad Bufo bufo on a coastal island in Central Norway

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Dag Dolmen

2016-04-01

Full Text Available The common frog (Rana temporaria and the common toad (Bufo bufo were introduced successfully to the coastal island of Frøya in Central Norway several times during 1960–2012. There is still a very high degree of conformity between sites where they were introduced and the present distribution of the two species. However, in western Frøya, a release of frogs about 1996 was followed by a quick expansion of their distribution area; in 2012 and 2013, breeding was registered close to 7 km westwards and eastwards, respectively, i.e. a population dispersal speed of approximately 0.4 km/yr. On eastern Frøya and some small islands in the archipelago, area expansions at another four frog localities have been prevented by ecological barriers like unfavourable limnetic or terrestrial habitats or salty water. Two local common toad populations on eastern Frøya do not show any expansion either. However, an apparently isolated record of the species on western Frøya in 2011 can possibly be explained by the expansion westwards of a population in northern central Frøya, where toads were introduced around 1995. This stretch is about 9.9 km, i.e. an average population dispersal speed of 0.6 km/yr.

Spatial-ecological divergence of the common frog (Rana temporaria L. and the moor frog (Rana arvalis Nilss. within their geographic ranges

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Kutenkov Anatoly

2017-03-01

It is only where there is the interpenetration of «core» landscapes of each species (large areas of the northern and western parts of the East European Plain, and a part of the West Siberian Plain contiguous to the Urals, one can observe the examples of real sympatry of R. arvalis and R. temporaria.

Alimentación de las ranas pardas, Rana gr. temporaria, en el circo de Piedrafita, (Pirineos, España

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Rodríguez Vieites, D.

1997-12-01

Full Text Available Feeding of high Pyrenean mountain brown frogs were studied in the pre-wintering period. The main prey is beetles (44'97o, two-winged flies (12'9% and bees, wasps, ants, etc (11'4%. For the whole of the frogs, the most frequent prey size is the small (smaller than 10 mm. Big frogs tend to consume bigger prey in not ,o. many quantity, while small frogs consume more quantity of preys but smaller in size. From prey way of life, frogs eat mainly terrestrial and aerial preys, although capture of aquatic prey was observed (11'5% and these preys were eaten inside the water.

Se ha estudiado la dieta de las ranas pardas en alta montaña pirenaica durante el periodo pre-invernal. Las ranas consumen principalmente coleópteros (44'9%, dípteros (12'9% e himenópteros (11'4%. Para el conjunto de todas las ranas estudiadas, las presas más consumidas son las de pequeño tamaño (menores de 10 mm. Las ranas de mayor talla tienden a consumir presas más grandes y en poca cantidad, mientras que las ranas pequeñas consumen más presas aunque de pequeño tamaño. En cuanto a forma de vida las presas más consumidas son terrestres y aéreas, aunque también se ha comprobado la captura de presas acuáticas (11'5% que son consumidas por las ranas dentro del agua.

Analysis of three amphibian populations with quarter-century long time-series.

OpenAIRE

Meyer, A H; Schimidt, B R; Grossenbacher, K

1998-01-01

Amphibians are in decline in many parts of the world. Long tme-series of amphibian populations are necessary to distinguish declines from the often strong fluctuations observed in natural populations. Time-series may also help to understand the causes of these declines. We analysed 23-28-year long time-series of the frog Rana temporaria. Only one of the three studied populations showed a negative trend which was probably caused by the introduction of fish. Two populations appeared to be densi...

Sexual dimorphism of extensor carpi radialis muscle size, isometric force, relaxation rate and stamina during the breeding season of the frog Rana temporaria Linnaeus 1758.

Science.gov (United States)

Navas, Carlos A; James, Rob S

2007-02-01

Mating success of individual male frogs within explosive breeding species can depend on their ability to compete for a mate and to hold onto that mate during amplexus. Such importance of amplexus has resulted in the evolution of sexual dimorphism in the morphology and contractile characteristics of the anuran forelimb muscles used during amplexus. The aims of our study were to use an explosive breeding frog (Rana temporaria) during the breeding season to compare extensor carpi radialis (ECR) muscle length, mass, isometric activation times, relaxation times, absolute force, relative force (stress) and fatigue between male and female frogs. We found that ECR muscle mass and length were greater (tenfold and 1.4-fold, respectively), absolute tetanic muscle force and relative tetanic force (stress) were greater (16-fold and 2.2-fold, respectively) and relaxation times were slower in males than in females. Male ECR muscles incompletely relaxed during fatigue tests and showed less fatigue than female muscles. These sex differences are likely to be beneficial to the male frogs in allowing them to produce relatively high absolute muscle forces for prolonged periods of time to hold onto their mate during amplexus.

The effect of the aluminum chloride – quercetin complex on Ca(2+,Mg(2+-ATPase activity and contraction dynamic properties of muscle tibialis anterior from Rana temporaria

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D. M. Nozdrenko

2015-12-01

Full Text Available Combined effect of aluminum chloride and quercetin solutions on the enzymatic activity and contraction dynamics of muscle fiber bundles of the Rana temporaria m. tibialis anterior was investigated. It was shown that these complexes inhibit muscle contraction. Linear reduction of Ca2+,Mg2+-ATPase activity induced by all of the used concentrations of AlCl3 – quercetin was demonstrated. It was found that complex of quercetin with AlCl3 has a greater inhibitory effect on muscle contraction dynamic and causes greater reduction during all periods of stimulation in comparison to the separate effect of the investigated compounds. All the studied concentrations of AlCl3 and quercetin solutions (AlCl3: 10-4-10-2 M; quercetin: 10-6-10-5 M caused concentration depended contraction strengths and lengths reduction. The decrease in strength and length of muscle contractions was of constant and mostly linear nature within observed timeframe as well as within each periods of contraction. The changes were least pronounced within pretetanic period, but were profound within terminal period of muscle activity. The changes in dynamic contraction properties and Ca2+,Mg2+-ATPase activity of sarcoplasmic reticulum under effect of the investigated compounds was minimal in the beginning of the muscle’s response to stimulus, prior to muscle strength reaching stable contraction level.

Revisión taxonómica de Alytes grandis Brunner (Amphibia, Anura

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Sanchiz, B.

1986-12-01

Full Text Available The holotype and only existing remain referred to Alytes grandis Brunner, 1957, presumably a discoglossid frog from the German Pleistocene, is examined and compared with other living and fossil Palaearctic anurans. The analysis rejects its validity as an independent extinct species, as The material is clearly within the known variability of living Rana temporaria Linnaeus, 1758, of which it should be considered merely a sinonym.

Se examina el holotipo y único resto atribuido de Alytes grandis Brunner, 1957, un supuesto discoglósido del Pleistoceno alemán, comparándose con otros anuros actuales y fósiles del Paleártico. El análisis permite desechar su pertenencia a una especie extinta independiente, siendo en cambio atribuible con toda claridad a la viviente Rana temporaria Linnaeus, 1758, de la que debe considerarse sinónimo.
Zum systematischen Status von Alytes grandis Brunner, 1957 (Amphibia, Anura. Der bislang einzig bekannte und von Brunner (1957 beschriebene Rest zu Alytes grandis aus pleistozänen Ablagerungen der Breitenberghöhle bei Gössweinstein (Fränk, Alb wird beschrieben und aufgrund ausführlicher Vergleichsuntersuchungen der rezenten Art Rana temporaria Linnaeus, 1758, zugeordnet, Alytes grandis Brunner, 1957, ist somit als synonyrn zu Rana temporaria zu betrachten.

Population size, survival, growth, and movements of Rana sierrae

Science.gov (United States)

Fellers, Gary M.; Kleeman, Patrick M.; Miller, David A. W.; Halstead, Brian J.; Link, William

2013-01-01

Based on 2431 captures of 757 individual frogs over a 9-yr period, we found that the population of R. sierrae in one meadow–stream complex in Yosemite National Park ranged from an estimated 45 to 115 adult frogs. Rana sierrae at our relatively low elevation site (2200 m) grew at a fast rate (K = 0.73–0.78), had high overwintering survival rates (44.6–95%), lived a long time (up to 16 yr), and tended to be fairly sedentary during the summer (100% minimum convex polygon annual home ranges of 139 m2) but had low year-to-year site fidelity. Even though the amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) has been present in the population for at least 13 yr, there was no clear downward trend as might be expected from reports of R. sierrae population declines associated with Bd or from reports of widespread population decline of R. sierrae throughout its range.

Rana

DEFF Research Database (Denmark)

Jørgensen, Søren Vissing

and for visualization. As a tool Rana offers a graphic user interface for live event visualization, agent feedback and simulation configuration. To establish Rana as an end-user tool, it is evaluated against the existing state of the art for multi-agent systems simulation tools and three different Rana models...... interface for defining the nature of an events propagation. This provides an interface for determination of event relevance during a simulation, and for visualization of a simulations event-scape. Two different simulations are presented that demonstrate event-processing functionality in agent design...

Helminth communities of two green frogs (Rana perezi and Rana saharica from both shores of the Alboran Sea

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Navarro P.

2006-12-01

Full Text Available The helminth communities of two populations of green frogs from both shores of the Alborán Sea (Western Mediterranean were studied. Of the 79 frogs examined for helminths, 39 individuals of the species Rana saharica were collected from Bab-Taza (Morocco, and 40 of the species Rana perezi were collected from the Natural Park of the Sierra de Grazalema (Spain. Although the species richness of helminths was identical in the two sampled areas, the differences observed in the structure of the helminth infracommunities were quite important. Statistically, significant differences were found between the species richness and the diversity of the infracommunities of R. perezi female population and the other three studied statistical populations. The helminth component communities of these two green frogs can be considered as depauperate, although their infracommunities present interactive features.

Laboratory studies bearing on pigment pattern polymorphisms in wild populations of Rana pipiens.

Science.gov (United States)

Merrell, D J

1972-01-01

Data are presented for 2,393 progeny from a number of crosses related to a study in ecological genetics of the Burnsi and Kandiyohi polymorphisms in natural populations of the leopard frog, Rana pipiens. No significant differences in viability were found between wild-type homozygotes (+/+) and Burnsi heterozygotes (B/+) or homozygotes (B/B). Similarly, no difference in viability was found between wild-type (+/+) and Kandiyohi heterozygotes (K/+) and homozygotes (K/K). However, there appears to be slight reduction in viability of the double dominant heterozygote (B/+; K/+) in comparison with (+/+), (B/+), and (K/+) progeny from the same cross.-The Kandiyohi heterozygotes (K/+) appeared to have a more rapid rate of development from fertilization through metamorphosis than wild-type (+/+) or Burnsi (B+/) or Burnsi-Kandiyohi heterozygotes (B+K/+). Since Kandiyohi is associated primarily with the prairie habitat (Merrell 1965), this finding suggests that the adaptive advantage of Kandiyohi lies in the more rapid rate of development of frogs carrying this gene, enabling them to complete metamorphosis before the prairie breeding ponds dry up.-Data are presented from crosses involving dorsal spot number. The results suggest that heredity plays a role in the determination of dorsal spot number but that non-genetic influences are also of considerable importance.-The results of these crosses are discussed with respect to their bearing on the formation of pigment patterns in Rana pipiens. From the available data it is clear that the pigment pattern in Rana pipiens is a complex trait influenced by major gene loci, by modifying genes, and by environmental effects. The relative importance of these factors varies depending on the particular combination of genetic and environmental conditions.

Population trends, survival, and sampling methodologies for a population of Rana draytonii

Science.gov (United States)

Fellers, Gary M.; Kleeman, Patrick M.; Miller, David A.W.; Halstead, Brian J.

2017-01-01

Estimating population trends provides valuable information for resource managers, but monitoring programs face trade-offs between the quality and quantity of information gained and the number of sites surveyed. We compared the effectiveness of monitoring techniques for estimating population trends of Rana draytonii (California Red-legged Frog) at Point Reyes National Seashore, California, USA, over a 13-yr period. Our primary goals were to: 1) estimate trends for a focal pond at Point Reyes National Seashore, and 2) evaluate whether egg mass counts could reliably estimate an index of abundance relative to more-intensive capture–mark–recapture methods. Capture–mark–recapture (CMR) surveys of males indicated a stable population from 2005 to 2009, despite low annual apparent survival (26.3%). Egg mass counts from 2000 to 2012 indicated that despite some large fluctuations, the breeding female population was generally stable or increasing, with annual abundance varying between 26 and 130 individuals. Minor modifications to egg mass counts, such as marking egg masses, can allow estimation of egg mass detection probabilities necessary to convert counts to abundance estimates, even when closure of egg mass abundance cannot be assumed within a breeding season. High egg mass detection probabilities (mean per-survey detection probability = 0.98 [0.89–0.99]) indicate that egg mass surveys can be an efficient and reliable method for monitoring population trends of federally threatened R. draytonii. Combining egg mass surveys to estimate trends at many sites with CMR methods to evaluate factors affecting adult survival at focal populations is likely a profitable path forward to enhance understanding and conservation of R. draytonii.

Modelling the impact of roads on regional population of Moor frogs (Rana arvalis)

DEFF Research Database (Denmark)

Pontoppidan, Maj-Britt

for decisions concerning road lay-out and mitigation measures. As model species was chosen the Moor frog (Rana arvalis). Populations of Moor frogs are assumed to follow a pattern of metapopulation dynamics, with colonisation, extinction and recolonisation of suitable habitat patches. Thus, road constructions...... to be constructed and analysed. The first scenario should be a map of the area as it is before the planned road construction (scenario 0). This analysis measures the ecological performance of the original landscape and is a reference against which other scenarios are to be compared. The second map (scenario 1......) should show the landscape as it is expected to be after the road constructions. In combination, the analyses of scenario 0 and scenario 1 make it possible to assess the effect of road construction on connectivity and population persistence. The analyses also constitute the basis for planning...

One-tone suppression in the frog auditory nerve

DEFF Research Database (Denmark)

Christensen-Dalsgaard, J; Jørgensen, M B

1996-01-01

Sixty-seven fibers of a sample of 401 in the auditory nerve of grassfrogs (Rana temporaria) showed one-tone suppression, i.e., their spontaneous activity was suppressed by tones. All fibers were afferents from the amphibian papilla with best frequencies between 100 and 400 Hz. Best suppression...

First report of freshwater leech Helobdella stagnalis (Rhyncobdellida: Glossiphoniidae as a parasite of an anuran amphibian

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Rocco Tiberti

2010-12-01

Full Text Available The authors describe the first case of parasitism on anuran amphibian, Rana temporaria, by the freshwater leech Helobdella stagnalis, in a mountainous area of northwestern Italy. The presence of skin abrasions and haemorrhages attributable to leech attack discards the hypothesis of a simple phoretic relationship between leech and frog.

Changes in dynamics processes of the muscles’ traction under influence of stress-factors

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D. M. Nozdrenko

2006-01-01

Full Text Available Change of fibers’ dynamic parameters of the frog Rana temporaria skeletal muscle m. tibialis traction under influence of modulated stimulation and aluminium chloride solutions was studied. At 10-4,5·10-4 and 10‑3 M·l-1 concentrations of aluminium chloride the nonlinear decrease of the muscle fibers’ traction parameters was observed.

Rana nigromaculata

Indian Academy of Sciences (India)

ONLINE RESOURCES. Development and characterization of 13 polymorphic microsatellite DNA markers for the pond green frog (Rana nigromaculata). JIE GONG1,2, HONG LAN1,2, SHENG-GUO FANG1,2 and QIU-HONG WAN1,2∗. 1College of Life Sciences, Zhejiang University, Hangzhou 310058, People's Republic of ...

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....

Spatial Amphibian Impact Assessment – a management tool for assessment of road effects on regional populations of Moor frogs (Rana arvalis)

DEFF Research Database (Denmark)

Pontoppidan, Maj-Britt; Nachman, Gøsta Støger

2013-01-01

viability. Analyses of maps without the planned road constructions will constitute a “null-model” against which other scenarios can be compared, making it possible to assess the effect of road projects on landscape connectivity and population dynamics. Analyses and comparisons of several...... demonstrate how SAIA can be used to assess which management measures would be best to mitigate the effect of landscape fragmentation caused by road constructions by means of a case study dedicated to the Moor frog (Rana arvalis).......An expanding network of roads and railways fragments natural habitat affecting the amount and quality of habitat and reducing connectivity between habitat patches with severe consequences for biodiversity and population persistence. To ensure an ecologically sustainable transportation system...

KARBOKSITERAPIJA – POTPORNA TERAPIJA U LIJEČENJU KRONIČNIH RANA

OpenAIRE

SINOŽIĆ, TAMARA; KOVAČEVIĆ, JADRANKA

2014-01-01

Karboksiterapija je potporna metoda liječenja kroničnih rana koja se provodi kutanim ili supkutanim ubrizgavanjem medicinskog ugljičnog dioksida (Co2). osnovni princip djelovanja ubrizganog plina Co2 je korekcija tkivne hipoksije temeljem bohrovog efekta. Djelujući na endotelne faktore rasta potiče neoangiogenezu te stimulirajući fibroblaste na sintezu kolagena što sve zajedno dovodi do boljeg zacjeljivanja rana. brojna su područja primjene karboksiterapije - od liječenja kroničnih rana, bole...

First report of Hepatozoon sp. in the Oregon spotted frog, Rana pretiosa.

Science.gov (United States)

Stenberg, Patricia L; Bowerman, William J

2010-07-01

From 2005 through 2008, we screened 650 Oregon spotted frogs (Rana pretiosa) from three populations in central Oregon, USA, for hemoparasites. A Hepatozoon sp., not previously reported in R. pretiosa, was found in one population of frogs, mostly as intracellular gamonts at a prevalence of 10.5% with parasitemias ranging from 0.02% to greater than 42% of erythrocytes within individual frogs. Intra-and extracellular merozoites were present, but rare. A potential vector, the mosquito Culex boharti, was common throughout the habitat of the population carrying Hepatozoon sp.

Leech presence on Iberian Brown Frog, Rana iberica, (Amphibia: Anura: Ranidae from north-western Spain

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César Ayres

2008-12-01

Full Text Available The authors describe a case of parasitism on Rana iberica by two species of leeches, Batracobdella sp. and Hirudo medicinalis, in a mountainous area of north-western Spain. Conservation implications of high parasite load on small and isolated populations are discussed.

THE MOCHE BOTANICAL FROG (La rana botánica mochica

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Donna McClelland †

2011-06-01

Full Text Available Plants and animals with features which identify them as supernaturals characterize the art of the Precolumbian Moche culture of northern Peru. Among these animals is a frog with feline attributes and a consistent association with manioc tubers, stalks, and plants, the Botanical Frog. The Botanical Frog appears to have been patterned on Leptodactylus pentadactylus. It is shown copulating with felines. Fine line painted vessels and ones with low relief decoration show the Botanical Frog performing as part of a ritual involving other animals and cultivated crops, suggesting that the Botanical Frog was associated with agriculture. ESPAÑOL: El arte de la cultura mochica de la costa norte del Perú presenta plantas y animales mostrando rasgos sobrenaturales. Uno de los animales es una rana con elementos felinos y asociada con tubérculos, ramas y plantas de yuca. La Rana Botánica probablemente tiene su origen en Leptodactylus pentadactylus, una rana carnívora de la selva amazónica. La Rana Botánica copula con felinos y, en vasijas pintadas con líneas finas o con escenarios representados en bajorrelieve, toma parte en ceremonias involucrando a otros animales y cosechas domésticas. Parece ser que la Rana Botánica era un ser sobrenatural asociado con la agricultura.

On the presence of Rana ridibunda ridibunda Pallas in the Netherlands

NARCIS (Netherlands)

Hoogmoed, M.S.

1975-01-01

Since long there has been a dispute whether in the Netherlands there occur one or two species of green frogs of the genus Rana. There has never been any doubt concerning the presence of Rana esculenta Linnaeus, a species widely distributed throughout the country (Van de Bund, 1964, 1968). The first

Hemoparasites in Oregon spotted frogs (Rana pretiosa) from central Oregon, USA.

Science.gov (United States)

Stenberg, Patricia L; Bowerman, William J

2008-04-01

Between 2001 and 2003, we screened blood smears of 156 Oregon spotted frogs (Rana pretiosa) from three populations in central Oregon for blood parasites. A Lankesterella sp. and a Trypanosoma sp. were detected in 31% and 35% of the frogs, respectively. Parasite loads were generally light, with Lankesterella sporozoites in 1-2% of erythrocytes, and extracellular trypanosomes were seen at rates of about one parasite per 200 fields of view at 1,000x. Little work has been published on hemoparasites of ranids in the western USA in the past 30 yr. Because of the recent taxonomic division of the Rana pretiosa complex, this may be the first published report of blood parasites for R. pretiosa sensu stricto. Both parasites reported here differed in morphologic features and morphometric comparisons from previous descriptions of anuran hemoparasites. Much work remains to sort out the taxonomy of hemoparasites among western USA ranids and to determine the ecological significance of these parasites; both tasks are important steps in understanding and managing these, and related, sensitive and threatened species.

Exposures to estradiol, ethinylestradiol and octylphenol affect survival and growth of Rana pipiens and Rana sylvatica tadpoles.

Science.gov (United States)

Hogan, Natacha S; Lean, David R S; Trudeau, Vance L

2006-08-01

Endocrine disrupting compounds (EDCs) are often detected in the aquatic environment and can negatively affect the health of wildlife populations. However, little is known about the sensitivity of native amphibians to EDCs. Wood frogs (Rana sylvatica) and Northern leopard frogs (Rana pipiens) were exposed to three estrogenic EDCs: estradiol (E2), ethinylestradiol (EE2), and 4-tert-octylphenol (OP). In addition, R. pipiens were exposed during two developmental stages (Gosner stages 26 and 36) to examine life-stage differences in sensitivity. Tadpoles were exposed for 2 wk to 8 nominal concentrations (0.25 microM-10 microM) of each compound. Individual mortality was recorded during the exposure period, while body weight was measured at the end of 2 wk. LC50 values were calculated, and differences in body weight between vehicle control and exposed groups were assessed. Rank order toxicity of the compounds for both R. pipiens stages and both species was OP > EE2 > E2. Gosner stage 26 tadpoles were more sensitive (LC50: E2 [5.57 microM], EE2 [3.01 microM], OP [1.36 microM]) to all three compounds when compared to stage 36 tadpoles (LC50: E2 [>10 microM], EE2 [4.17 microM], OP [2.80 microM]). Interspecies comparisons revealed R. sylvatica tadpoles (LC50: E2 [2.50 microM], EE2 [1.89 microM], OP [0.74 microM]) as being more sensitive to the three compounds than R. pipiens (LC50: E2 [4.56 microM], EE2 [2.75 microM], OP [1.42 microM]). Xenoestrogen exposure also affected tadpole body weight which may have long-term adverse effects on the rate of metamorphosis. These results provide toxicological data needed for assessing sublethal effects of estrogenic compounds on amphibian development and suggest that environmental levels of OP may pose a serious risk to the health of amphibian populations.

Diversity and phylogeography of Northeast Asian brown frogs allied to Rana dybowskii (Anura, Ranidae).

Science.gov (United States)

Yang, Bao-Tian; Zhou, Yu; Min, Mi-Sook; Matsui, Masafumi; Dong, Bing-Jun; Li, Pi-Peng; Fong, Jonathan J

2017-07-01

We investigated the species diversity and phylogeography of the Northeast Asian brown frogs allied to Rana dybowskii (the R. dybowskii species complex: R. dybowskii, R. pirica, and R. uenoi) using four mitochondrial and three nuclear loci. Phylogenetic analyses confirmed the existence of three distinct species in this complex; using extensive molecular data, we confirm the validity of Rana uenoi recognized as a distinct species, and infer R. dybowskii and R. pirica to be sister species. Also, we included populations from previously unsampled regions in Northeast China, and identified them to be R. dybowskii. While many species in Northeast Asia diverged due to Pleistocene glaciation, divergence-dating analyses inferred older, Miocene speciation in the R. dybowskii species complex. Ancestral area reconstruction identified the orogenic movement of the Changbai Mountain Range and the opening of the Sea of Japan/East Sea being major events influencing allopatric speciation. Copyright © 2017 Elsevier Inc. All rights reserved.

Variation in genotoxic stress tolerance among frog populations exposed to UV and pollutant gradients

International Nuclear Information System (INIS)

Marquis, Olivier; Miaud, Claude; Ficetola, Gentile Francesco; Bocher, Aurore; Mouchet, Florence; Guittonneau, Sylvie; Devaux, Alain

2009-01-01

Populations of widely distributed species can be subjected to unequal selection pressures, producing differences in rates of local adaptation. We report a laboratory experiment testing tolerance variation to UV-B and polycyclic aromatic hydrocarbons (PAHs) among common frog (Rana temporaria) populations according to their natural exposure level in the field. Studied populations were naturally distributed along two gradients, i.e. UV-B radiation with altitude and level of contamination by PAHs with the distance to emitting sources (road traffic). Tadpoles from eight populations were subjected to (1) no or high level of artificial UV-B; (2) four concentrations of benzo[a]pyrene (BaP) (0, 50, 250, 500 μg L -1 ); (3) simultaneously to UV-B and BaP. Since both stressors are genotoxic, the number of micronucleated erythrocytes (MNE) in circulating red blood cells was used as a bioindicator of tadpole sensitivity. High-altitude populations appear to be locally adapted to better resist UV-B genotoxicity, as they showed the lowest MNE numbers. Conversely, no correlation was observed between levels of PAH contamination in the field and tadpole tolerance to BaP in the laboratory, indicating the absence of local adaptation for BaP tolerance in these populations. Nevertheless, the decrease of MNE formation due to BaP exposure with altitude suggests that high-altitude populations were intrinsically more resistant to BaP genotoxicity. We propose the hypothesis of a co-tolerance between UV-B and BaP in high-altitude common frog populations: local adaptation to prevent and/or repair DNA damage induced by UV-B could also protect these highland populations against DNA damage induced by BaP. The results of this study highlight the role of local adaptation along pollutant gradients leading to tolerance variation, which implies that is it necessary to take into account the history of exposure of each population and the existence of co-tolerance that can hide toxic effects of a new

Variation in genotoxic stress tolerance among frog populations exposed to UV and pollutant gradients

Energy Technology Data Exchange (ETDEWEB)

Marquis, Olivier [Laboratoire d' Ecologie Alpine, UMR CNRS 5553, Universite de Savoie, Technolac, Le Bourget du Lac (France); Miaud, Claude, E-mail: claude.miaud@univ-savoie.fr [Laboratoire d' Ecologie Alpine, UMR CNRS 5553, Universite de Savoie, Technolac, Le Bourget du Lac (France); Ficetola, Gentile Francesco [Laboratoire d' Ecologie Alpine, UMR CNRS 5553, Universite de Savoie, Technolac, Le Bourget du Lac (France); Department of Biology, Universita degli Studi di Milano, Milan (Italy); Bocher, Aurore [Laboratoire de Chimie Moleculaire et Environnement, Universite de Savoie, Le Bourget du Lac (France); Mouchet, Florence [Laboratoire d' Ecologie Fonctionnelle, UMR CNRS-UPS-INPT 5245, Institut National Polytechnique-ENSAT, Auzeville-Tolosane (France); Guittonneau, Sylvie [Laboratoire de Chimie Moleculaire et Environnement, Universite de Savoie, Le Bourget du Lac (France); Devaux, Alain [Laboratoire des Sciences de l' Environnement, Ecole Nationale des Travaux Publics de l' Etat, INRA-EFPA, Vaulx-en-Velin (France)

2009-11-08

Populations of widely distributed species can be subjected to unequal selection pressures, producing differences in rates of local adaptation. We report a laboratory experiment testing tolerance variation to UV-B and polycyclic aromatic hydrocarbons (PAHs) among common frog (Rana temporaria) populations according to their natural exposure level in the field. Studied populations were naturally distributed along two gradients, i.e. UV-B radiation with altitude and level of contamination by PAHs with the distance to emitting sources (road traffic). Tadpoles from eight populations were subjected to (1) no or high level of artificial UV-B; (2) four concentrations of benzo[a]pyrene (BaP) (0, 50, 250, 500 {mu}g L{sup -1}); (3) simultaneously to UV-B and BaP. Since both stressors are genotoxic, the number of micronucleated erythrocytes (MNE) in circulating red blood cells was used as a bioindicator of tadpole sensitivity. High-altitude populations appear to be locally adapted to better resist UV-B genotoxicity, as they showed the lowest MNE numbers. Conversely, no correlation was observed between levels of PAH contamination in the field and tadpole tolerance to BaP in the laboratory, indicating the absence of local adaptation for BaP tolerance in these populations. Nevertheless, the decrease of MNE formation due to BaP exposure with altitude suggests that high-altitude populations were intrinsically more resistant to BaP genotoxicity. We propose the hypothesis of a co-tolerance between UV-B and BaP in high-altitude common frog populations: local adaptation to prevent and/or repair DNA damage induced by UV-B could also protect these highland populations against DNA damage induced by BaP. The results of this study highlight the role of local adaptation along pollutant gradients leading to tolerance variation, which implies that is it necessary to take into account the history of exposure of each population and the existence of co-tolerance that can hide toxic effects of a

Phylogenetic relationships of leopard frogs (Rana pipiens complex) from an isolated coastal mountain range in southern Sonora, Mexico.

Science.gov (United States)

Pfeiler, E; Markow, T A

2008-10-01

Mitochondrial DNA sequence data from the control region and 12S rRNA in leopard frogs from the Sierra El Aguaje of southern Sonora, Mexico, together with GenBank sequences, were used to infer taxonomic identity and provide phylogenetic hypotheses for relationships with other members of the Rana pipiens complex. We show that frogs from the Sierra El Aguaje belong to the Rana berlandieri subgroup, or Scurrilirana clade, of the R. pipiens group, and are most closely related to Rana magnaocularis from Nayarit, Mexico. We also provide further evidence that Rana magnaocularis and R. yavapaiensis are close relatives.

Ugrizna rana lica

OpenAIRE

Knežević, Bojana; Knežević, Predrag; Uglešić, Vedran; Zubčić, Vedran

2006-01-01

Ugrizne rane jedne su od najčešćih ozljeda u ljudi. Najčešći su ugrizi pasa (više od 80%), mačaka i ljudi. U velikom postotku ugrizne rane locirane su na licu, osobito kod djece. Najčešće bakterije koje se mogu naći u ugriznoj rani su aerobi i anaerobi iz oralne flore napadača i aerobi s kože žrtve. Liječenje ugriznih rana lica je specifično u odnosu prema ostalim dijelovima tijela. Ugrizne rane lica primarno se šivaju, a zbog dobre prokrvljenosti komplikacije su rijetke, no ako se dogode mog...

JST Thesaurus Headwords and Synonyms: Rana catesbeiana [MeCab user dictionary for science technology term[Archive

Lifescience Database Archive (English)

Full Text Available MeCab user dictionary for science technology term Rana catesbeiana 名詞 一般 * * * * ウシ...ガエル ウシガエル ウシガエル Thesaurus2015 200906051181134488 C LS05 UNKNOWN_2 Rana catesbeiana

Terrestrial pesticide exposure of amphibians: an underestimated cause of global decline?

Science.gov (United States)

Brühl, Carsten A; Schmidt, Thomas; Pieper, Silvia; Alscher, Annika

2013-01-01

Amphibians, a class of animals in global decline, are present in agricultural landscapes characterized by agrochemical inputs. Effects of pesticides on terrestrial life stages of amphibians such as juvenile and adult frogs, toads and newts are little understood and a specific risk assessment for pesticide exposure, mandatory for other vertebrate groups, is currently not conducted. We studied the effects of seven pesticide products on juvenile European common frogs (Rana temporaria) in an agricultural overspray scenario. Mortality ranged from 100% after one hour to 40% after seven days at the recommended label rate of currently registered products. The demonstrated toxicity is alarming and a large-scale negative effect of terrestrial pesticide exposure on amphibian populations seems likely. Terrestrial pesticide exposure might be underestimated as a driver of their decline calling for more attention in conservation efforts and the risk assessment procedures in place do not protect this vanishing animal group.

Effects of environmental radiation of Kori nuclear power plant on the human population

International Nuclear Information System (INIS)

Kim, Y.J.

1979-01-01

In order to clarify and protect the effects of environmental radiation according to the operation of Kori nuclear power plant on human population, the base line survey for the human monitoring, the fauna of land nocturnal insects, and the karyotypes of amphibian species which have been living around the power plant site were carried out. ''Kilchunri'' population which took for the human monitoring lie within a 2km distance from power plant site. Human monitoring, house and food characteristics, individual experience of X-ray exposures, human chromosome analysis and fauna of nocturnal land insects were surveyed and expressed in numerical tables. Chromosome number obtained from the amphibia which were collected around the power plant area was as follows; Kaloula borealis 2N=30, Rana amurensis 2N=26, Rana dybouskii 2N=24, Rana rugosa 2N=26, Rana migromaculata 2N=26, Rana plancyi 2N=26, Bombina orientalis 2N=24, Hyla arborea 2N=24, Bufo stejnegeri 2N=22, and Bufo bufo 2N=22. (author)

Frogs as a part of the Eneolithic diet. Archaeozoological records from the Czech Republic (Kutná Hora-Denemark site, Řivnáč Culture)

Czech Academy of Sciences Publication Activity Database

Kyselý, René

2008-01-01

Roč. 35, č. 1 (2008), s. 143-157 ISSN 0305-4403 Institutional research plan: CEZ:AV0Z80020508 Keywords : amphibians * common frog (Rana temporaria) * prehistoric food * anatomy representation * seasonality * chalcolithic * Central Europe Subject RIV: EG - Zoology Impact factor: 1.779, year: 2008 http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WH8-4NT57V1-1&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=393499f111a5c12f133425d45f4f6f01

[ACTIVITY OF Ca2+,Mg(2+)-ATPase OF SARCOPLASMIC RETICULUM AND CONTRACTION STRENGTH OF THE FROG SKELETAL MUSCLES UNDER THE EFFECT OF ORGANOPHOSPHORUS INSECTICIDES].

Science.gov (United States)

Nozdrenko, D M; Korchinska, L V; Soroca, V M

2015-01-01

The results of an experimental study of organophosphorus insecticides, including pirimiphosmethyl, diazinon and chlorpyrifos caused a decline of the contraction properties in m. tibialis anterior fiber bundles of Rana temporaria, as well as sarcoplasmic reticulum Ca2+, Mg(2+)-ATPase enzymatic activity reduction are outlined in this paper. Concentration-dependent strengths response diminishing in isolated skeletal muscle fiber bundles as a result of non-cholinergic influence of organophosphorus insecticides were found. A decrease of Ca2+, Mg(2+)-ATPase enzymatic activity in sarcoplasmic reticulum was observed after administration of each insecticide. The most significant inhibition of this enzyme was observed when using chlorpyrifos.

Final report on effects of environmental radiation of Kori nuclear power plant on human population

International Nuclear Information System (INIS)

Kim, Y.J.; Kim, J.B.; Chung, K.H.; Lee, K.S.; Kim, S.R.; Yang, S.Y.

1980-01-01

In order to clarify and protect the effects of environmental radiation according to the operation of Kori nuclear power plant on the human population, the base line survey for the human monitoring, human life habits, expected individual exposure dose, frequencies of chromosomal aberration, gene frequencies and karyotypes in amphibia, fauna, and radiation sensitivities in microorganisms which have been living around the power plant site were carried out. Kilchonri population which took for the human monitoring lie within a 2 km distance from the power plant site. Human monitoring, house and food characteristics, individual experience of x-ray exposures, human chromosome analysis and fauna were surveyed and expressed in numerical tables. Chromosome number obtained from the amphibia which were collected around the power plant area was as follows: Kaloula borealis 2N=30, Rana amurensis 2N=26, Rana dybouskii 2N=24, Rana rugosa 2N=26, Rana nigromaculata 2N=26, Rana plancyi 2N=26, Bombina orientalis 2N=24, Hyla arborea 2N=24, Bufo stejnegeri 2N=22, Bufo bufo 2N=22. (author)

O sufixo -rana no português falado pelo caboclo amazonense

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Orlando Azevedo

2012-12-01

Full Text Available O artigo aborda a formação de palavras com o sufixo -rana no português falado em seis localidades situadas na região do Médio Solimões no Estado do Amazonas. O corpus para a análise foi retirado das respostas dos informantes ao questionário semântico-lexical da tese de Azevedo¹, que está em andamento e que trata da variação dialetal na região do Baixo Amazonas e do Médio Solimões. Para os propósitos da pesquisa, nossa fundamentação foi baseada no modelo da morfologia gerativa a fim de que fosse possível a construção de uma regra aplicável às bases que esse sufixo seleciona. Os resultados mostraram a existência de formações neológicas, uma vez que não foram encontradas em obras lexicográficas. Além disso, o sufixo -rana ao selecionar bases substantivas não muda a classe gramatical da palavra primitiva ao formar novos substantivos. Devido à regularidade, foi possível estabelecermos uma regra de formação de palavras para o sufixo -rana no português falado nessa região da Amazônia brasileira.

O SUFIXO -RANA NO PORTUGUÊS FALADO PELO CABOCLO AMAZONENSE

Directory of Open Access Journals (Sweden)

Orlando Azevedo

2012-01-01

Full Text Available O artigo aborda a formação de palavras com o sufixo –rana no português falado em seis localidades situadas na região do Médio Solimões no Estado do Amazonas. O corpus para a análise foi retirado das respostas dos informantes ao questionário semântico-lexical da tese de Azevedo, que está em andamento e que trata da variação dialetal na região do Baixo Amazonas e do Médio Solimões. Para os propósitos da pesquisa, nossa fundamentação foi baseada no modelo da morfologia gerativa a fim de que fosse possível a construção de uma regra aplicável às bases que esse sufixo seleciona. Os resultados mostraram a existência de formações neológicas, uma vez que não foram encontradas em obras lexicográficas. Além disso, o sufixo –rana ao selecionar bases substantivas não muda a classe gramatical da palavra primitiva ao formar novos substantivos. Devido à regularidade, foi possível estabelecermos uma regra de formação de palavras para o sufixo –rana no português falado nessa região da Amazônia brasileira.

Type I collagen from bullfrog ( Rana catesbeiana ) fallopian tube ...

African Journals Online (AJOL)

Rana catesbeiana) with a yield of 16.4%, on a dry weight basis. Sodium dodecyl sulphate polyacylamide-gel electrophoresis (SDS-PAGE) showed that the PSC contained two alpha components (α1 and α2) and was classified as type I collagen ...

Morphometric variation in the Tunisian green frog, Rana saharica ...

African Journals Online (AJOL)

Rana saharica is the most widely distributed anuran in Tunisia. We examined morphological variation in 124 specimens as a function of their geographical origin, using univariate and multivariate statistics with traditional morphometrics. Our results supported the existence of three morphotypes of this species, correctly ...

El declive de una población costera cantábrica de Rana bermeja (Rana temporaria

Directory of Open Access Journals (Sweden)

GOSA, A.

1998-01-01

Algunas de las características reproductoras de la población son de notable alargamiento de su periodo de puesta, que comienza a primeros de noviembre y puede extenderse hasta febrero y primeros de marzo ; la baja fecundidad de las hembras (media de 1006 huevos por puesta y la permanencia de los machos en los charcos donde se reproducen(algunos pasan en ellos hasta dos meses y medio.El pico reproductor medio para el periodo de estudio se produce en la segunda decena de diciembre, fecha en la que ya se ha hecho el 60% de la puesta total.

Columbia spotted frog (Rana luteiventris) in southeastern Oregon: A survey of historical localities, 2009

Science.gov (United States)

Pearl, Chistopher A.; Galvan, Stephanie K.; Adams, Michael J.; McCreary, Brome

2010-01-01

The Columbia spotted frog (Rana luteiventris) occupies a large range in western North America and is comprised of at least three genetic units. Concern exists regarding the status of the Great Basin populations in Oregon, Idaho, and Nevada. We surveyed target and nearby alternate sites on public lands in southeastern Oregon where there was evidence that Columbia spotted frogs were historically present. We found the species at 59.5 percent (25 of 42) of target or nearby alternate sites. They were in 15 of 23 permanent streams and 8 of 13 intermittent streams. Our surveys do not provide evidence of widespread population losses in our sites. Interpretation of status of Columbia spotted frogs in this study is limited by a lack of precision in some of the historical locations and by our inability to determine if locations where only adults were indicated in the historical record once had breeding populations. Our results support the need for continued investigation of these populations.

Endoparasites in some Swedish Amphibians

DEFF Research Database (Denmark)

Cedhagen, Tomas

1988-01-01

A study was made of the endoparasites in specimens of Rana arvalis and R. temporaria collected on two occasions from a locality of southern Sweden. Some frogs were investigated directly after capture while other frogs were kept hibernating and the composition of the parasites as well...... as the behaviour of the parasites were studied after the termination of hibernation. Twelve species of parasites were found. Six of them, Polystoma integerrimum, Pleurogenes claviger (Trematoda), Rhabdias bufonis, Oswaldocruzia filiformis, Cosmocerca ornata and Oxysomatium brevicauda- tum (Nematoda), have...... not previously been reported from Sweden. The late Prof. O. Nybelin's unpublished records of parasites found in Swedish amphibians are also given....

Activity of Ca(2+,Mg(2+-ATPase of sarcoplasmic reticulum and contraction strength of the frog skeletal muscles under the effect of organophosphorus insecticides

Directory of Open Access Journals (Sweden)

D. M. Nozdrenko

2015-08-01

Full Text Available The results of an experimental study of organo­phosphorus insecticides, including pirimiphosmethyl, diazinon and chlorpyrifos caused a decline of the contraction properties in m. tibialis anterior fiber bundles of Rana temporaria, as well as sarcoplasmic reticulum Ca2+,Mg2+-ATPase enzymatic activity reduction are outlined in this paper. Concentration-dependent strengths response diminishing in isolated skeletal muscle fiber bundles as a result of non-cholinergic influence of organophosphorus insecticides were found. A decrease of Ca2+,Mg2+-ATPase enzymatic activity in sarcoplasmic reticulum was observed after administration of each insecticide. The most significant inhibition of this enzyme was observed when using chlorpyrifos.

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

Indian Academy of Sciences (India)

Unknown

The ability of bronze frog Rana temporalis tadpoles (pure or mixed parental lines) to ... less of whether they are siblings or non-siblings in a group, which correlates well with ..... Sutherland W J and Parker G A 1992 The relationship between.

Efectivos poblacionales de la Rana ágil (Rana dalmatina y uso del hábitat reproductor en Navarra

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GOSA, Alberto

2002-01-01

Full Text Available La población navarra de Rana dalmatina se encuentra fragmentada en 4 núcleos incomunicados, con baja disponibilidad de humedales para la reproducción (entre 2 y 15 por área. La población de hembras adultas fluctúa anualmente entre 1000 y 1500 individuos, sin considerar de la La Barranca, todavía no investigada. La conservación de la especie depende de la gestión de las zonas húmedas.

Climatic influences on the breeding biology of the agile frog ( Rana dalmatina)

Science.gov (United States)

Combes, Magali; Pinaud, David; Barbraud, Christophe; Trotignon, Jacques; Brischoux, François

2018-02-01

Severe population declines of amphibians have been shown to be attributed to climate change. Nevertheless, the various mechanisms through which climate can influence population dynamics of amphibians remain to be assessed, notably to disentangle the relative synergetic or antagonistic influences of temperature and precipitations on specific life history stages. We investigated the impact of rainfall and temperature on the egg-clutch abundance in a population of agile frog ( Rana dalmatina) during 29 years (1987-2016) on 14 breeding sites located in Brenne Natural Park, France. Specifically, we examined the influence of environmental conditions occurring during five temporal windows of the year cycle corresponding to specific life history stages. Overall, our results suggest that the year-to-year fluctuations of egg-clutch abundances in Brenne Natural Park were partly dependent on local climatic conditions (rainfall and temperature). Climate seemed to influence breeding frogs during the autumn-winter period preceding reproduction. Spring and summer conditions did not influence reproduction. Additionally, we failed to detect effects of climatic conditions on newly metamorphosed individuals. Other factors such as density dependence and inter-specific interactions with introduced predators are likely to play a significant role in reproduction dynamics of the studied frog populations.

Big mountains but small barriers: population genetic structure of the Chinese wood frog (Rana chensinensis) in the Tsinling and Daba Mountain region of northern China.

Science.gov (United States)

Zhan, Aibin; Li, Cheng; Fu, Jinzhong

2009-04-09

Amphibians in general are poor dispersers and highly philopatric, and landscape features often have important impacts on their population genetic structure and dispersal patterns. Numerous studies have suggested that genetic differentiation among amphibian populations are particularly pronounced for populations separated by mountain ridges. The Tsinling Mountain range of northern China is a major mountain chain that forms the boundary between the Oriental and Palearctic zoogeographic realms. We studied the population structure of the Chinese wood frog (Rana chensinensis) to test whether the Tsinling Mountains and the nearby Daba Mountains impose major barriers to gene flow. Using 13 polymorphic microsatellite DNA loci, 523 individuals from 12 breeding sites with geographical distances ranging from 2.6 to 422.8 kilometers were examined. Substantial genetic diversity was detected at all sites with an average of 25.5 alleles per locus and an expected heterozygosity ranging from 0.504 to 0.855, and two peripheral populations revealed significantly lower genetic diversity than the central populations. In addition, the genetic differentiation among the central populations was statistically significant, with pairwise FST values ranging from 0.0175 to 0.1625 with an average of 0.0878. Furthermore, hierarchical AMOVA analysis attributed most genetic variation to the within-population component, and the between-population variation can largely be explained by isolation-by-distance. None of the putative barriers detected from genetic data coincided with the location of the Tsinling Mountains. The Tsinling and Daba Mountains revealed no significant impact on the population genetic structure of R. chensinensis. High population connectivity and extensive juvenile dispersal may account for the significant, but moderate differentiation between populations. Chinese wood frogs are able to use streams as breeding sites at high elevations, which may significantly contribute to the

In vivo study of lens regeneration in Rana cyanophlyctis under ...

African Journals Online (AJOL)

SAM

2014-03-12

Mar 12, 2014 ... enhanced the percentage lens regeneration not only in young tadpoles but also in froglets. Lens regeneration ability ... Influence of vitamin A and ascorbic acid on lens regeneration in young, mature tadpoles and froglets of the frog Rana cyanophlyctis. Group .... ingested by macrophages. Dorsal iris cells ...

Effect of rana galamensis–based diet on the activities of some enzymes and histopathology of selected tissues of albino rats

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Basiru Olaitan Ajiboye

2016-10-01

Full Text Available The effect of Rana galamensis-based diet on the activities of some enzymes and histopathology of selected tissues of albino rats was investigated for eight weeks. A total of sixteen albino rats weighing between 29.15 and 26.01g (21 days old were divided into two groups. The first group contains animals fed on casein-based diet (control; the second group was fed on Rana galamensis-based diet. The animals were fed with their appropriate diet on daily basis and on the eight weeks of the experiment the animals were sacrificed using diethyl ether as anesthesia, blood was collected by cardiac puncture and organs of interest were harvested. Thereafter, organ to body weight ratio, some biochemical parameters and histopathology examination were carried out. There was no significant difference (p >0.05 in the organ to body weight ratio of the animals fed on control and Rana galamensis-based diets. Also, there was no significant different (p >0.05 in the activities of all the enzymes (ALP [alkaline phosphatase], AST [asparate transaminase], ALT [alanine transaminase], and γGT [gamma glutamyl transferase] investigated in the selected tissues and serum of rats fed on Rana galamensis- based diet when compared with the control. In addition, histological examinations of hepatocyte's rats fed on Rana galamensis- based diet show normal architecture structure when compared with the control. The insignificant different in the activities of all the enzymes studies (ALP, AST, ALT and γGT indicated no organ damage, supported by the normal histology studies. The obtained results may imply that Rana galamensis is safe for consumption.  Normal 0 false false false EN-US X-NONE X-NONE

Anthropogenic and ecological drivers of amphibian disease (ranavirosis.

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Alexandra C North

Full Text Available Ranaviruses are causing mass amphibian die-offs in North America, Europe and Asia, and have been implicated in the decline of common frog (Rana temporaria populations in the UK. Despite this, we have very little understanding of the environmental drivers of disease occurrence and prevalence. Using a long term (1992-2000 dataset of public reports of amphibian mortalities, we assess a set of potential predictors of the occurrence and prevalence of Ranavirus-consistent common frog mortality events in Britain. We reveal the influence of biotic and abiotic drivers of this disease, with many of these abiotic characteristics being anthropogenic. Whilst controlling for the geographic distribution of mortality events, disease prevalence increases with increasing frog population density, presence of fish and wild newts, increasing pond depth and the use of garden chemicals. The presence of an alternative host reduces prevalence, potentially indicating a dilution effect. Ranavirosis occurrence is associated with the presence of toads, an urban setting and the use of fish care products, providing insight into the causes of emergence of disease. Links between occurrence, prevalence, pond characteristics and garden management practices provides useful management implications for reducing the impacts of Ranavirus in the wild.

Pseudacris triseriata (western chorus frog) and Rana sylvatica (wood frog) chytridiomycosis

Science.gov (United States)

Rittman, S.E.; Muths, E.; Green, D.E.

2003-01-01

The chytrid fungus Batrachochytrium dendrobatidis is a known pathogen of anuran amphibians, and has been correlated with amphibian die-offs worldwide (Daszak et. al. 1999. Emerging Infectious Diseases 5:735-748). In Colorado, B. dendrobatidis has infected Boreal toads (Bufo boreas) (Muths et. al., in review) and has been identified on museum specimens of northern leopard frogs (Rana pipiens) (Carey et. al. 1999. Develop. Comp. Immunol. 23:459-472). We report the first verified case of chytrid fungus in chorus frogs (Pseudacris triseriata) and wood frogs (Rana sylvatica) in the United States. We collected seven P. triseriata, and two adult and two juvenile R. sylvatica in the Kawuneeche Valley in Rocky Mountain National Park (RMNP) during June 2001. These animals were submitted to the National Wildlife Health Center (NWHC) as part of an amphibian health evaluation in RMNP. Chorus frogs were shipped in one container. Wood frog adults and juveniles were shipped in two separate containers. Histological examinations of all chorus frogs and 3 of 4 wood frogs were positive for chytrid fungus infection. The fourth (adult) wood frog was too decomposed for meaningful histology. Histological findings consisted of multifocally mild to diffusely severe infections of the epidermis of the ventrum and hindlimb digital skin. Chytrid thalli were confined to the thickened epidermis (hyperkeratosis), were spherical to oval, and occasional thalli contained characteristic discharge pores or zoospores (Green and Kagarise Sherman 1999. J. Herpetol 35:92-103; Fellers et al. 2001. Copeia 2001:945-953). We cannot confirm that all specimens carried the fungus at collection, because infection may have spread from one individual to all other individuals in each container during transport. Further sampling of amphibians in Kawuneeche Valley is warranted to determine the rate of infection and mortality in these populations.

Maximizing Sampling Efficiency and Minimizing Uncertainty in Presence/Absence Classification of Rare Salamander Populations

Science.gov (United States)

2008-10-31

of the Apalachicola River drainage. Although this proposed division in classification appears to be generally accepted by the herpetological community...breeding in small forest ponds. Herpetological Review 33(4):275-280. Carle, F. L. and M. R. Strub. 1978. A new method for estimating population size...gopher frogs (Rana capito) and southern leopard frogs (Rana sphenocephala). Journal of Herpetology 42: 97-103. Grevstad, F.S. 2005. Simulating

Trophic ecology and microhabitat utilization by the Bufo gargarizans, Rana guentheri, and Rana limnocharis in southwestern China

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Tonglei Yu

2012-02-01

Full Text Available We studied the trophic ecology and microhabitat use of the Asiatic toad, Bufo gargarizans Cantor, 1842; Guentheri frog, Rana guentheri (Boulenger, 1882; and the Ricefield frog, Rana limnocharis (Boie, 1834. These three species are common around Nanchong City, in southwestern China, where they live in the same habitat before hibernation. The main objective of this study was to analyze the diets and patterns of coexistence relative to the microhabitat of each species. In the Asiatic toad, based on index of relative importance, the diet was dominated by adult Coleoptera, Isopoda, and Hymenoptera (29.53%, 22.07%, and 15.20%, respectively, while the Guenther's frog and Ricefield frog ingested predominantly Orthoptera (67.44% and 40.94%, respectively. The standardized feeding niche breadth of the Asiatic toad (0.277 was wider than that of the Guentheri frog (0.177 and Ricefield frog (0.269. The overlap in the trophic niche (prey proportion between the toad and two species of frog was low (toad vs. Guentheri frog, C H = 0.526; toad vs. Ricefield frog, C H = 0.521, while this was high for the two species of frogs (C H = 0.942. The three species also differed in microhabitat use. Asiatic toads showed strong preference for small roads close to shrubs or pre-harvest corn, while Guenther's frogs preferred bare surfaces on habitat edges, and Ricefield frogs showed a preference for bare surfaces as feeding sites in the middle of habitat. The difference in diet observed during three species seems to be explained by the difference in microhabitat use and body size of three species.

The esophagus anatomic-histology of bull frog ("Rana catesbeiana" Shaw, 1802 Anatomo-histologia do esôfago da rã touro ("Rana catesbeiana" Shaw, 1802

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Carlos Eduardo Lino Pinto

2008-04-01

Full Text Available Aiming to describe the esophage functional morpho – histology of bull frog (Rana catebeiana Shaw, 1802, twenty bull frog, mean body weight of 85.00 ± 2.03 g, were used. The esophageal mucosa architecture is defined by thick longitudinal folds, showing an esophageal ciliated pseudostratified epithelium with mucous cells and pluricellular glands; the esophageal muscular coat is composed by inner circular muscular lamina, and by outer longitudinal muscular lamina.Com o objetivo de descrever a anatomo histologia funcional do esôfago da rã touro (Rana catesbeiana Shaw, 1802, foram utilizados 20 (vinte exemplares de rã touro com peso médio de 85,00 ± 2,03 g. Verificou-se que a arquitetura da mucosa esofágica é definida por pregas espessas e longitudinais, com epitélio esofágico do tipo pseudo estratificado ciliado com células mucosas e glândulas pluricelulares; a túnica muscular esofágica é constituida pela túnica muscular circular, mais interna, e pela túnica muscular longitudinal, mais externa.

Big mountains but small barriers: Population genetic structure of the Chinese wood frog (Rana chensinensis in the Tsinling and Daba Mountain region of northern China

Directory of Open Access Journals (Sweden)

Li Cheng

2009-04-01

Full Text Available Abstract Background Amphibians in general are poor dispersers and highly philopatric, and landscape features often have important impacts on their population genetic structure and dispersal patterns. Numerous studies have suggested that genetic differentiation among amphibian populations are particularly pronounced for populations separated by mountain ridges. The Tsinling Mountain range of northern China is a major mountain chain that forms the boundary between the Oriental and Palearctic zoogeographic realms. We studied the population structure of the Chinese wood frog (Rana chensinensis to test whether the Tsinling Mountains and the nearby Daba Mountains impose major barriers to gene flow. Results Using 13 polymorphic microsatellite DNA loci, 523 individuals from 12 breeding sites with geographical distances ranging from 2.6 to 422.8 kilometers were examined. Substantial genetic diversity was detected at all sites with an average of 25.5 alleles per locus and an expected heterozygosity ranging from 0.504 to 0.855, and two peripheral populations revealed significantly lower genetic diversity than the central populations. In addition, the genetic differentiation among the central populations was statistically significant, with pairwise FST values ranging from 0.0175 to 0.1625 with an average of 0.0878. Furthermore, hierarchical AMOVA analysis attributed most genetic variation to the within-population component, and the between-population variation can largely be explained by isolation-by-distance. None of the putative barriers detected from genetic data coincided with the location of the Tsinling Mountains. Conclusion The Tsinling and Daba Mountains revealed no significant impact on the population genetic structure of R. chensinensis. High population connectivity and extensive juvenile dispersal may account for the significant, but moderate differentiation between populations. Chinese wood frogs are able to use streams as breeding sites at high

The role of desensititation in decay time of miniature endplate currents in frogs Rana ridibunda and Rana temporaria

Czech Academy of Sciences Publication Activity Database

Giniatullin, R. A.; Talantova, M. V.; Vyskočil, František

2001-01-01

Roč. 39, č. 3 (2001), s. 287-292 ISSN 0168-0102 R&D Projects: GA AV ČR IAA7011902; GA MŠk VS97099; GA MŠk OK 267 Grant - others:RFBR(RU) 98-04-48044; INTAS(BE) 2000-1147 Institutional research plan: CEZ:AV0Z5011922 Keywords : frog * desensitisation * miniature endplate potential Subject RIV: ED - Physiology Impact factor: 1.770, year: 2001

ULOGA DEBRIDMANA U LIJEČENJU KRONIČNIH RANA

OpenAIRE

HULJEV, DUBRAVKO; GAJIĆ, ALEKSANDAR; TRILLER, CIRIL; KECELJ LESKOVEC, NADA

2013-01-01

Debridement je proces uklanjanja mrtvog tkiva iz rane. Struktura, boja i neugodni mirisi devitaliziranog tkiva se razlikuju. osim toga, devitalizirano tkivo može biti suho ili sa secernacijom. Devitalizirano tkivo usporava ili u potpunosti onemogućuje zarastanje rane te je indicirano da ga se u okviru liječenja rana mora odstraniti. Cilj debridmana je pretvaranje kronične rane u stanje akutne rane i iniciranje procesa zaraštavanja. Debridement je osnovni postupak u liječenju svake rane, ali i...

Delayed metamorphosis and recurrence of bacterial infection in irradiated Rana clamitans tadpoles

International Nuclear Information System (INIS)

Hart, D.R.

1982-03-01

X-ray doses of 5 and 10 Gy (1 Gy/min) given to premetamorphic Green Frog (Rana clamitans) tadpoles delayed their metamorphosis relative to unirradiated controls. Previous pathogenic bacterial infections recurred in irradiated animals prior to metamorphic climax. Limited mortality occurred during metamorphic climax, 80-105 days after irradiation

Food Habits of the Endemic Long Legged Wood Frog, Rana Pseudodalmatina (Amphibia, Ranidae, in Northern Iran

Directory of Open Access Journals (Sweden)

Najibzadeh M.

2016-08-01

Full Text Available Iranian long legged wood frog, Rana pseudodalmatina Eiselt & Schmidtler, 1971 is a brown frog species endemic to the Hyrcanian forest. The objective of the present study is to collect detailed information on the feeding habits of 44 specimens of this species (24 ♂, 20 ♀ by analyzing the stomach contents of individuals from 10 populations inhabiting range. The food habit of R. pseudodalmatina generally varies by the availability of surrounding prey items, and it is a foraging predator, the food of which consists largely of Coleoptera (mainly Carabidae, Dytiscidae and Haliplidae, Diptera (Muscidae and Hymenoptera (Formicidae, and no difference was found between females and males in the stomach content.

RANA, a real-time multi-agent system simulator

DEFF Research Database (Denmark)

Jørgensen, Søren Vissing; Demazeau, Yves; Hallam, John

2016-01-01

for individualisation and abstraction while retaining efficiency. Events are managed by the C++ simulator core. Full run state can be recorded for post-processed visualisation or analysis. The new tool is demonstrated in three different cases: a mining robot simulation, which is purely action based; an agent......-based setup that is verifies the high precision exhibited by RANAs simulation core; and a state-based firefly-like agent simulation that models real-time responses to fellow agents' signals, in which event propagation and reception affect the result of the simulation....

Nomenclatural notes on living and fossil amphibians

Directory of Open Access Journals (Sweden)

Martín, C.

2012-06-01

Taylor, 1942; Lithobates rexroadensis for Rana rexroadensis Taylor, 1942; Lithobates robustocondylus for Anchylorana robustocondyla Taylor, 1942; Ommatotriton roehrsi for Triturus roehrsi Herre, 1955; Pelophylax barani for Rana barani Rückert-Ülkumen, 1980; Pelophylax meriani for Rana meriani Meyer, 1853; Pelophylax pueyoi for Rana pueyoi Navás, 1922a; Pelophylax quellenbergi for Rana quellenbergi Navás, 1922; Philoria borealis for Kyarranus borealis Tyler, 1991; Pseudepidalea belogorica for Bufo belogoricus Ratnikov, 1993; Pseudepidalea plana for Bufo planus Ratnikov, 1993; Pseudepidalea prisca for Bufo priscus Spinar, Klembara et Meszáros, 1993, and Pseudepidalea stranensis for Bufo stranensis Nemec, 1972. The names Geyeriellinae Brame, 1958, Palaeurodelidae Brame, 1958, Prosalamandridae Stefano, 1903, Lipelucidae Huene, 1956, Rana temporaria fossilis Stefanov, 1951, Salteniidae Kuhn, 1962, Vieraellidae Reig, 1961, and Voigtiellinae Brame, 1958 are nomenclaturally deemed unavailable. The family name based on Scapherpeton Cope, 1876 is Scapherpetidae and not Scapherpetonidae nor Scapherpetontidae.

Una revisión de anfibios extintos y actuales en estado fósil (Allocaudata, Anura y Caudata ha permitido detectar diversos casos que precisan cambios nomenclaturales a fin de estabilizar la taxonomía del grupo. Los cambios nomenclaturales incluyen homonimias, correcciones de variantes gramaticales y autorías, disponibilidad de nombres, y en especial la propuesta de nuevas combinaciones, necesarias para ajustar algunos taxones paleontológicos a los modelos de relaciones evolutivas entre formas vivientes, fundamentados en filogenias moleculares. Las nuevas combinaciones que se proponen son: Anaxyrus defensor para Bufo defensor Meylan, 2005; Anaxyrus hibbardi para

Changes in growth rate and macroelement and trace element accumulation in Hydrocharis morsus-ranae L. during the growing season in relation to environmental contamination.

Science.gov (United States)

Polechońska, Ludmiła; Samecka-Cymerman, Aleksandra; Dambiec, Małgorzata

2017-02-01

The temporal variations in plant chemistry connected with its life cycle may affect the cycling of elements in an ecosystem as well as determine the usefulness of the species in phytoremediation and bioindication. In this context, there is a gap in knowledge on the role of floating plants for elements cycling in aquatic reservoirs. The aim of the study was to determine if there are variations in Hydrocharis morsus-ranae (European frog-bit) bioaccumulation capacity and the growth rate of its population during the growing season and to test the impact of environmental pollution on these features. The content of macroelements (Ca, K, Mg, N, Na, P, S) and trace metals (Cd, Co, Cu, Cr, Hg, Fe, Mn, Ni, Pb, Zn) was determined in H. morsus-ranae collected monthly from June to October from habitats differing in environmental contamination. The results showed that the highest content of most trace metals (Co, Cr, Cu, Hg, Mn, Ni, Zn) and some nutrients (N, P) in plants as well as the greatest bioaccumulation efficiency occurred simultaneously in the beginning of the growing season. In the following months, a dilution effect (manifested by a decrease in content) related to the rapid growth was observed. Co, Mn, and Ni content in plant tissues reflected the level of environmental contamination throughout the growing season which makes H. morsus-ranae a potential biomonitor of pollution for these metals. Considering the great bioaccumulation ability, high sensitivity to contamination, and low biomass of European frog-bit in polluted systems, further investigation is required to assess the real phytoremediation capability of the species.

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 ...

Effects of exposure to ultraviolet light on the development of Rana pipiens, the northern leopard frog

International Nuclear Information System (INIS)

Williams, J.J.; Wofford, H.W.

1996-01-01

The increase in ultraviolet light intensity levels due to ozone depletion recently has been linked to the decline in amphibian population. In this experiment, eggs and larvae of Rana pipiens were subjected to differing amounts of ultraviolet radiation to determine the effects of ultraviolet light on the development of amphibian tadpoles. The total length, length of body without tail, and maximum width of each specimen was recorded for a month of the tadpoles' development, including several measurements after the ultraviolet exposures were concluded. It was found that ultraviolet exposure significantly reduced the size of the organisms in comparison with the control group in all three measured areas. Ultraviolet radiation altered the health and appearance of the exposed organisms and was lethal at large amounts. This experiment showed that ultraviolet radiation could cause many problems in developing amphibians. By slowing their development and physically weakening predation, thus contributing to a decline in overall population levels

Mating strategy and breeding patterns of the foothill yellow-legged frog (Rana boylii)

Science.gov (United States)

Clara A. Wheeler; Hartwell H. Welsh Jr.

2008-01-01

The Foothill Yellow-legged Frog (Rana boylii) has declined across much of its native range in California. Improper stream management may lower egg mass survival and reduce the availability of suitable breeding habitats. We collected data during six breeding-seasons (2002-2007) along an unregulated stream in northwestern California. We monitored...

cytogenetic effects in populations of amphibians Rana arvalis living on the radio-contaminated area

Energy Technology Data Exchange (ETDEWEB)

Yushkova, E.; Bodnar, I.; Zainullin, V. [Institute of Biology of Komi Scientific Centre of the Ural Branch of the Russian Academy of Sciences (Russian Federation)

2014-07-01

The study of the features reactions of the animals a differing complicated individual development (metamorphosis) and living in conditions of radioactive contamination is an important trend in the modern radio-ecology. This information is of interest not only from the point of view of detection the mechanisms of radiobiological effects (hyper-radiosensitivity, hormesis, radio-adaptation, etc.) but also viewpoint of predicting delayed radiation effects that is necessary at account the normalization of technogeneous loading on natural ecosystems. An assessment of the level of cytogenetic damages (single-strand and double-strand DNA breaks) in the blood cells of tadpoles of Rana arvalis living in areas contaminated of wastes radium production (Russia, Komi Republic, Ukhta district) was conducted. Using this biological matter as a bioindicator due to the fact that development amphibian is carried out by metamorphosis and includes larval stage. At this stage post-embryonic development of an individual are the most sensitive to anthropogenic impact. To exclude the effects of other factors (temperature, age-specific peculiarities, overpopulation, etc.) on the formation of DNA damages from the studied reservoirs were taken laying eggs of amphibians (12-15 egg laying from the area) which afterwards are contain in strictly controlled laboratory conditions using water, belt silt, plants of native pond. The reaction of amphibians on the contamination was assessed by the level of DNA damage by method Comet assay was determined. With each egg laying were selected for 7 even-aged individuals. Total for cytogenetic analysis was used 189 individuals. It is shown that in animals that develop on the radio-contaminated area the level of single-strand DNA (alkaline pH version of the Comet assay) was higher than in the control area. According an estimate to the level of double-strand DNA (neutral pH version of the Comet assay) significant differences not was found. The high variability

ALUMINUM CHLORIDE EFFECT ON Ca2+,Mg(2+)-ATPase ACTIVITY AND DYNAMIC PARAMETERS OF SKELETAL MUSCLE CONTRACTION.

Science.gov (United States)

Nozdrenko, D M; Abramchuk, O M; Soroca, V M; Miroshnichenko, N S

2015-01-01

We studied enzymatic activity and measured strain-gauge contraction properties of the frog Rana temporaria m. tibialis anterior muscle fascicles during the action of aluminum chloride solution. It was shown that AlCl3 solutions did not affect the dynamic properties of skeletal muscle preparation in concentrations less than 10(-4) M Increasing the concentration of AlCl3 to 10(-2) M induce complete inhibition of muscle contraction. A linear correlation between decrease in Ca2+,Mg(2+)-ATPase activity of sarcoplasmic reticulum and the investigated concentrations range of aluminum chloride was observed. The reduction in the dynamic contraction performance and the decrease Ca2+,Mg(2+)-ATPase activity of the sarcoplasmic reticulum under the effect of the investigated AlCl3 solution were minimal in pre-tetanus period of contraction.

Primeras observaciones sobre la alimentación de sapos (Bufo bufo juveniles durante la emergencia en el País Vasco

Directory of Open Access Journals (Sweden)

VIGNES, J.C.

1998-01-01

Full Text Available Se aportan las primeras observaciones sobre Bufo bufo, que vienen a completar los estudios de alimentación de anuros juveniles realizados en el País Vasco durante el periodo de emergencia. Se analiza el contenido estomacal de 35 individuos (longitud media de 11,54 mm emergidos de una charca a comienzos de agosto. Todos los jóvenes sapos se alimentan de invertebrados terrestres desde su emergencia, siendo los ácaros de presa más consumida (75,7%, seguida de los coleópteros adultos y los himenópteros alados. Aunque las presas fundamentales son las mismas, los regímenes comparados de los metamorfoseados de varias especies de anuros (Rana dalmatina, R. temporaria et Hyla arborea muestran diferencias en la selección trófica.

Aluminum chloride effect on Ca(2+,Mg(2+-ATPase activity and dynamic parameters of skeletal muscle contraction

Directory of Open Access Journals (Sweden)

D. M. Nozdrenko

2015-10-01

Full Text Available We studied enzymatic activity and measured strain-gauge contraction properties of the frog Rana temporaria m. tibialis anterior muscle fascicles during the action of aluminum chloride solution. It was shown that AlCl3 solutions did not affect the dynamic properties of skeletal muscle preparation in concentrations less than 10-4 M. Increasing the concentration of AlCl3 to 10-2 M induce complete inhibition of muscle contraction. A linear correlation between decrease in Ca2+,Mg2+-ATPase activity of sarcoplasmic reticulum and the investigated concentrations range of aluminum chloride was observed. The reduction in the dynamic contraction performance and the decrease Ca2+,Mg2+-ATPase activity of the sarcoplasmic reticulum under the effect of the investigated AlCl3 solution were minimal in pre-tetanus period of contraction.

Multifarious selection through environmental change: acidity and predator-mediated adaptive divergence in the moor frog (Rana arvalis).

Science.gov (United States)

Egea-Serrano, Andrés; Hangartner, Sandra; Laurila, Anssi; Räsänen, Katja

2014-04-07

Environmental change can simultaneously cause abiotic stress and alter biological communities, yet adaptation of natural populations to co-changing environmental factors is poorly understood. We studied adaptation to acid and predator stress in six moor frog (Rana arvalis) populations along an acidification gradient, where abundance of invertebrate predators increases with increasing acidity of R. arvalis breeding ponds. First, we quantified divergence among the populations in anti-predator traits (behaviour and morphology) at different rearing conditions in the laboratory (factorial combinations of acid or neutral pH and the presence or the absence of a caged predator). Second, we evaluated relative fitness (survival) of the populations by exposing tadpoles from the different rearing conditions to predation by free-ranging dragonfly larvae. We found that morphological defences (relative tail depth) as well as survival of tadpoles under predation increased with increasing pond acidity (under most experimental conditions). Tail depth and larval size mediated survival differences among populations, but the contribution of trait divergence to survival was strongly dependent on prior rearing conditions. Our results indicate that R. arvalis populations are adapted to the elevated predator pressure in acidified ponds and emphasize the importance of multifarious selection via both direct (here: pH) and indirect (here: predators) environmental changes.

Multifarious selection through environmental change: acidity and predator-mediated adaptive divergence in the moor frog (Rana arvalis)

Science.gov (United States)

Egea-Serrano, Andrés; Hangartner, Sandra; Laurila, Anssi; Räsänen, Katja

2014-01-01

Environmental change can simultaneously cause abiotic stress and alter biological communities, yet adaptation of natural populations to co-changing environmental factors is poorly understood. We studied adaptation to acid and predator stress in six moor frog (Rana arvalis) populations along an acidification gradient, where abundance of invertebrate predators increases with increasing acidity of R. arvalis breeding ponds. First, we quantified divergence among the populations in anti-predator traits (behaviour and morphology) at different rearing conditions in the laboratory (factorial combinations of acid or neutral pH and the presence or the absence of a caged predator). Second, we evaluated relative fitness (survival) of the populations by exposing tadpoles from the different rearing conditions to predation by free-ranging dragonfly larvae. We found that morphological defences (relative tail depth) as well as survival of tadpoles under predation increased with increasing pond acidity (under most experimental conditions). Tail depth and larval size mediated survival differences among populations, but the contribution of trait divergence to survival was strongly dependent on prior rearing conditions. Our results indicate that R. arvalis populations are adapted to the elevated predator pressure in acidified ponds and emphasize the importance of multifarious selection via both direct (here: pH) and indirect (here: predators) environmental changes. PMID:24552840

The tactile-stimulated startle response of tadpoles: acceleration performance and its relationship to the anatomy of wood frog (Rana sylvatica), bullfrog (Rana catesbeiana), and American toad (Bufo americanus) tadpoles.

Science.gov (United States)

Eidietis, Laura

2006-04-01

I described the tactile-stimulated startle response (TSR) of wood frog (Rana sylvatica), bullfrog (Rana catesbeiana), and American toad (Bufo americanus) tadpoles. One purpose was to rank species in terms of maximum acceleration performance. Also, I tested whether anatomical indicators of performance potential were predictive of realized performance. TSRs were elicited in a laboratory setting, filmed at 250 Hz, and digitally analyzed. TSRs began with two, initial body curls during which tadpoles showed a broad spectrum of movement patterns. TSR performance was quantified by maximum linear acceleration and maximum rotational acceleration of the head/body, both of which tended to occur immediately upon initiation of motion ( wood frog > American toad. The species' rank order for the anatomical indicator of rotational acceleration potential was bullfrog > wood frog = American toad. Thus, the anatomical indicators roughly predicted the rank order of interspecific average performance. However, the anatomical indicators did not correlate with individual tadpole performance. Variability in behavioral patterns may obscure the connection between anatomy and performance. This is seen in the current lack of intraspecific correlation between a morphological indicator of acceleration capacity and acceleration performance.

Site fidelity of the declining amphibian Rana sierrae (Sierra Nevada yellow-legged frog)

Science.gov (United States)

Kathleen Matthews; Haiganoush Preisler

2010-01-01

From 1997 to 2006, we used mark–recapture models to estimate the site fidelity of 1250 Sierra Nevada yellow-legged frogs (Rana sierrae) in Kings Canyon National Park, California, USA, during their three main activity periods of overwintering, breeding, and feeding. To quantify site fidelity, the tendency to return to and reuse previously occupied...

Ultrastructure and localisation of late-sporogonic developmental stages of Sphaerospora ranae (Myxosporea: Sphaerosporidae)

Czech Academy of Sciences Publication Activity Database

Jirků, Miloslav; Bartošová, Pavla

2014-01-01

Roč. 61, č. 4 (2014), s. 311-321 ISSN 0015-5683 R&D Projects: GA ČR GAP506/10/2330; GA ČR(CZ) GPP506/11/P724 Institutional support: RVO:60077344 Keywords : Amphibia * Anura * Europe * kidneys * myxospore * Myxozoa * Rana * sporogony * synchronisation * in situ hybridisation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.147, year: 2014

Habitat use and home range of the endangered gold-spotted pond frog (Rana chosenica).

Science.gov (United States)

Ra, Nam-Yong; Sung, Ha-Cheol; Cheong, Seokwan; Lee, Jung-Hyun; Eom, Junho; Park, Daesik

2008-09-01

Because of their complex life styles, amphibians and reptiles living in wetlands require both aquatic and terrestrial buffer zones in their protected conservation areas. Due to steep declines in wild populations, the gold-spotted pond frog (Rana chosenica) is listed as vulnerable by the IUCN. However, lack of data about its movements and use of habitat prevents effective conservation planning. To determine the habitat use and home range of this species, we radio-tracked 44 adult frogs for 37 days between 10 July and 4 Nov. 2007 to observe three different populations in the breeding season, non-breeding season, and late fall. The gold-spotted pond frog was very sedentary; its daily average movement was 9.8 m. Frogs stayed close to breeding ponds (within 6.6 m), and did not leave damp areas surrounding these ponds, except for dormancy migration to terrestrial sites such as dried crop fields. The average distance of dormancy migration of seven frogs from the edge of their breeding ponds was 32.0 m. The average size of an individual's home range was 713.8 m(2) (0.07 ha). The year-round population home range, which accounts for the home ranges of a population of frogs, was determined for two populations to be 8,765.0 m(2) (0.88 ha) and 3,700.9 m(2) (0.37 ha). Our results showed that to conserve this endangered species, appropriately sized wetlands and extended terrestrial buffer areas surrounding the wetlands (at least 1.33 ha, diameter 130 m) should be protected.

Radiocesium accumulation in the anuran frog, Rana tagoi tagoi, in forest ecosystems after the Fukushima Nuclear Power Plant accident

International Nuclear Information System (INIS)

Takahara, Teruhiko; Endo, Satoru; Takada, Momo; Oba, Yurika; Nursal, Wim Ikbal; Igawa, Takeshi; Doi, Hideyuki; Yamada, Toshihiro; Okuda, Toshinori

2015-01-01

Amphibians are key components in forest food webs. When examining radioactive contamination in anurans, it is important to understand how radiocesium transfer occurs from lower to higher trophic levels in forest ecosystems. We investigated the activity concentration of radiocesium ( 134 Cs and 137 Cs) in Tago's brown frog (Rana tagoi tagoi) captured on the forest floor approximately 2.5 years after the Fukushima Nuclear Power Plant (FNPP) accident. We collected 66 R. tagoi tagoi at different distances from the FNPP. Radiocesium accumulation showed positive correlations with the air radiation dose rate and litter contamination but not with distance from the FNPP. Whole-body radioactivity showed no correlation with body mass or length. Our results suggest that differences in the available food items result in large variability in individual contamination. Contamination level monitoring in terrestrial and aquatic amphibian is necessary for clarifying the processes and mechanisms of radiocesium transfer through forest food webs. - Highlights: • Radiocesium level in Rana tagoi tagoi from forests near Fukushima was assessed. • Radiocesium accumulation was related to air dose rate and litter contamination. • Differences in dietary intake might lead to variability in individual contamination. • Transfer of radiocesium among trophic levels can occur via anurans. - Rana tagoi tagoi accumulates radiocesium in forest floor habitats near Fukushima

N.C. Rana: The Life of a `Comet' in the Astrophysical World

OpenAIRE

Mukhopadhyay, Utpal; Ray, Saibal

2014-01-01

Narayan Chandra Rana, a person with extraordinary potential from a remote village of Bengal, India, came into the limelight of the international scientific world through his exceptional talent, zeal and courage. In his very short life-span, he excelled not only into various branches of astrophysics, but also took a leading role in science popularization, text book writing etc. In this paper, life and works of that budding scientist of India have been discussed from multifarious viewpoints.

Oral chytridiomycosis in the mountain yellow-legged frog (Rana muscosa)

Science.gov (United States)

Fellers, G.M.; Green, E.D.; Longcore, J.E.

2001-01-01

The chytrid fungus Batrachochytrium dendrobatidis was originally reported in wild frog populations in Panama and Australia, and from captive frogs in the U.S. National Zoological Park (Washington, DC). This recently described fungus affects the keratinized epidermis of amphibians and has been implicated as a causative factor in the declines of frog populations. We report here the presence of B. dendrobatidis in larval and recently metamorphosed mountain yellow-legged frogs (Rana muscosa) in or near the Sierra Nevada Mountains of California, an area where declines have been documented in all five species of native anurans. Forty-one percent (158 of 387) of larval R. muscosa examined in the field with a hand lens and 18% (14 of 79) of preserved larvae had abnormalities of the oral disc. Twenty-eight larvae were collected from 10 sites where tadpoles had been observed with missing or abnormally keratinized mouthparts, and 24 of these were examined for infection. Sixty-seven percent (16 of 24) of these tadpoles were infected with B. dendrobatidis. Batrachochytrium dendrobatidis was cultured from both tadpoles and recent metamorphs from one of these sites. Tadpoles with mouthpart abnormalities or confirmed chytrid fungus infections were collected at 23 sites spanning a distance of > 440 km and an elevational range from 1658-3550 m. Life-history traits of R. muscosa may make this species particularly susceptible to infection by Batrachochytrium. We recommend that biologists examine tadpoles for oral disc abnormalities as a preliminary indication of chytridiomycosis. Further, we believe that biologists should take precautions to prevent spreading this and other amphibian diseases from one site to another.

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...

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...

Comparative toxicity of chlorpyrifos, diazinon, malathion and their oxon derivatives to larval Rana boylii

International Nuclear Information System (INIS)

Sparling, D.W.; Fellers, G.

2007-01-01

Organophosphorus pesticides (OPs) are ubiquitous in the environment and are highly toxic to amphibians. They deactivate cholinesterase, resulting in neurological dysfunction. Most chemicals in this group require oxidative desulfuration to achieve their greatest cholinesterase-inhibiting potencies. Oxon derivatives are formed within liver cells but also by bacterial decay of parental pesticides. This study examines the toxicity of chlorpyrifos, malathion and diazinon and their oxons on the foothill yellow-legged frog (Rana boylii). R. boylii is exposed to agricultural pesticides in the California Central Valley. Median lethal concentrations of the parental forms during a 96 h exposure were 3.00 mg/L (24 h) for chlorpyrifos, 2.14 mg/L for malathion and 7.49 mg/L for diazinon. Corresponding oxons were 10 to 100 times more toxic than their parental forms. We conclude that environmental concentrations of these pesticides can be harmful to R. boylii populations. - Laboratory tests on the toxicity of OP insecticides and their oxons suggest that they may be acutely lethal to amphibians at ecologically relevant concentrations

Comparative toxicity of chlorpyrifos, diazinon, malathion and their oxon derivatives to larval Rana boylii

Energy Technology Data Exchange (ETDEWEB)

Sparling, D.W. [Cooperative Wildlife Research Laboratory, Department of Zoology and Center for Ecology, Southern Illinois University, LS II, MS6504, Carbondale, IL 62901 (United States)]. E-mail: dsparl@siu.edu; Fellers, G. [Western Ecology Research Center, U.S. Geological Survey, Point Reyes National Seashore, Point Reyes, CA 94956 (United States)

2007-06-15

Organophosphorus pesticides (OPs) are ubiquitous in the environment and are highly toxic to amphibians. They deactivate cholinesterase, resulting in neurological dysfunction. Most chemicals in this group require oxidative desulfuration to achieve their greatest cholinesterase-inhibiting potencies. Oxon derivatives are formed within liver cells but also by bacterial decay of parental pesticides. This study examines the toxicity of chlorpyrifos, malathion and diazinon and their oxons on the foothill yellow-legged frog (Rana boylii). R. boylii is exposed to agricultural pesticides in the California Central Valley. Median lethal concentrations of the parental forms during a 96 h exposure were 3.00 mg/L (24 h) for chlorpyrifos, 2.14 mg/L for malathion and 7.49 mg/L for diazinon. Corresponding oxons were 10 to 100 times more toxic than their parental forms. We conclude that environmental concentrations of these pesticides can be harmful to R. boylii populations. - Laboratory tests on the toxicity of OP insecticides and their oxons suggest that they may be acutely lethal to amphibians at ecologically relevant concentrations.

Micronuclei induction in Rana catesbeiana tadpoles by the pyrethroid insecticide lambda-cyhalothrin

OpenAIRE

Campana, Marcela Alejandra; Panzeri, Ana María; Moreno, Víctor Jorge; Dulout, Fernando Noel

2003-01-01

Pyrethroid lambda-cyhalothrin genotoxicity was evaluated using the micronucleus test in Rana catesbeiana tadpoles. The effects of concentration and exposure time on the micronuclei frequency were studied in blood smears obtained from tadpoles exposed to four concentrations (0.02, 0.1, 0.2 and 0.4 mg/L) of the compound for 24, 48, 72 and 96 h and 8, 15, 20 and 30 days. As a positive control, tadpoles were exposed to cyclophosphamide (5 mg/L). The micronucleated cell frequency was expressed per...

Pre-hibernation energy reserves in a temperate anuran, Rana chensinensis, along a relatively fine elevational gradient

Science.gov (United States)

Lu, X.; Li, B.; Li, Y.; Ma, X.; Fellers, G.M.

2008-01-01

Temperate anurans have energy substrates in the liver, fat bodies, carcass and gonads; these stores provide support for metabolism and egg production during hibernation, and for breeding activities in spring. This paper compares the energy budget shortly before hibernation among Rana chensinensis populations at elevations of 1400, 1700 and 2000 m along a river in northern China. The larger frogs, regardless of elevation, had relatively heavy storage organs and the masses of nearly all these organs were positively correlated with each other. After controlling for the effect of body size, we found no significant difference in energetic organ mass among different age classes for each of the three populations. There were sexual differences in energy strategy. Males in all populations accumulated greater reserves in liver, fat bodies and carcass than did females. In contrast, females put more energy into their ovaries and oviducts. Frogs from higher elevations tended to have heavier organs than those from lower elevations; however, the pattern did not vary systematically along fine environmental gradients. Mid-elevation R. chensinensis built up significantly more reserves than low-elevation individuals, but were similar to their highland conspecifics. Males from higher elevations tended to have heavier liver and fat bodies; females were similar in liver and ovary mass across all elevations, but formed heavier fat bodies, oviducts and somatic tissue at higher elevation sites.

Acute Toxicity of a Heavy Metal Cadmium to an Anuran, the Indian Skipper Frog Rana cyanophlyctis

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Ajai Kumar Srivastav

2016-08-01

Full Text Available Background: There has been increasing awareness throughout the world regarding the remarkable decrease in amphibian population. For such amphibian population decline several causes have been given. Cadmium, a heavy metal is released both from natural sources (leaching of cadmium rich soils and anthropogenic activities to the aquatic and terrestrial environments. This study evaluated the toxicity of heavy metal cadmium to Indian skipper frog Rana cyanophlyctis. Methods: For the determination of LC50 values for cadmium, four-day static renewal acute toxicity test was used. Five replicates each containing ten frogs were subjected to each concentration of cadmium chloride (15, 20, 25, 30, 35, 40, 45 and 50 mg/L. At different exposure periods (24, 48, 72 and 96 h, the mortality of the frog was subjected to Probit analysis with the POLO-PC software (LeOra Software to calculate the LC50 and 95% confidence level. Results: The LC50 values of cadmium chloride for the frog R. cyanophlyctis at 24, 48, 72, and 96 h are 32.586, 29.994, 27.219 and 23.048 mg/L, respectively. The results have been discussed with the toxicity reported for other aquatic vertebrate --fish. Conclusion: Cadmium caused mortality to the frog and this could be one of the reasons for population decline of frogs which inhabit water contaminated with heavy metals.

Influence of anuran prey on the condition and distribution of Rana muscosa in the Sierra Nevada

Science.gov (United States)

K.L. Pope; K.R. Matthews

2002-01-01

Mountain yellow-legged frogs (Rana muscosa) at high elevations of the Sierra Nevada must obtain enough food during summer to survive 7–9 winter months when their aquatic habitats are frozen and food is presumably unavailable. Adults of R. muscosa prey on a variety of organisms, including aquatic and terrestrial invertebrates and...

Bioaccumulation of macro- and trace elements by European frogbit (Hydrocharis morsus-ranae L.) in relation to environmental pollution.

Science.gov (United States)

Polechońska, Ludmiła; Samecka-Cymerman, Aleksandra

2016-02-01

The aim of present study was to investigate the level of trace metals and macroelements in Hydrocharis morsus-ranae collected from regions differing in the degree and type of pollution. Concentrations of 17 macro- and microelements were determined in roots and shoots of European frogbit as well as in water and bottom sediments from 30 study sites. Plants differed in concentrations of elements and bioaccumulation capacity depending on the characteristics of dominant anthropogenic activities in the vicinity of the sampling site. Shoots of H. morsus-ranae growing in the vicinity of organic chemistry plants and automotive industry contained particularly high levels of Cd, Co, and S. Plants from area close to heat and power plant, former ferrochrome industry and new highway, were distinguished by the highest concentrations of Cr, Cu, and Pb. European frogbit from both these regions contained more Fe, Hg, Mn, Ni, and Zn than plants from agricultural and recreational areas. The concentrations of alkali metals and Co, Fe, and N in H. morsus-ranae were elevated in relation to the natural content in macrophytes irrespectively to their content in the environment. Based on the values of Bioaccumulation and Translocation Factors, European frogbit is an accumulator for Co, Cr, Cu, Fe, K, Mn, Ni, Pb, and Zn and a good candidate for phytoremediation of water polluted with Co, Cu, Hg, K, Mn, and Ni. The amount of Co and Mn removed from water and accumulated in the plant biomass during the vegetation season was considerably high.

Acid-base regulation in tadpoles of Rana catesbeiana exposed to environmental hypercapnia

DEFF Research Database (Denmark)

Busk, Morten; Larsen, Erik Hviid; Jensen, Frank B.

1997-01-01

Tadpoles of Rana catesbeiana were exposed to different levels of environmental hypercapnia. The acid-base regulatory response differed from that in adult amphibians in showing a high degree of pH compensation in the extracellular fluid (65-85%) and complete compensation in the intracellular fluid......-base equivalents marginally, suggesting that mobilisable CaCO3 stores were depleted during the first exposure to hypercapnia and that they were not refilled. The CaCO3 stores may normally be mobilised during the slowly developing internal hypercapnia that occurs during metamorphosis....

Acute Toxicity of an Organophosphate Insecticide Chlorpyrifos to an Anuran, Rana cyanophlyctis

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Ajai Kumar Srivastav

2017-02-01

Full Text Available Background: Chlorpyrifos is an organophosphate pesticide that elicits broad-spectrum insecticidal activity against a number of important arthropod pests. Determining the insecticides’ toxicity to amphibians can give us a better understanding regarding the role of toxicants in amphibian declines. This information would be beneficial to assess their ecological relevance at environmental concentrations. The present study assessed toxicity of chlorpyrifos to an anuran Rana cyanophlyctis. Methods: For the determination of LC50 values for chlorpyrifos, four-day static renewal acute toxicity test was used. Five replicates each containing ten frogs were subjected to each concentration of chlorpyrifos (2, 4, 6, 8, 10, 12, 14 and 16 mg/L for the test. Mortality of the frog at different exposure periods (24, 48, 72 and 96 h was subjected to Probit analysis with the POLO-PC software (LeOra Software to calculate the LC50 and 95% confidence level. Results: The LC50 values of chlorpyrifos for the frog R. cyanophlyctis at 24, 48, 72, and 96 h were 8.252, 7.254, 6.247 and 4.993mg/L, respectively. Conclusion: Mortality has been noticed in chlorpyrifos treated frogs related to the decline in amphibian population. Therefore, chlorpyrifos should not be used near water reservoirs.

A new record for American Bullfrog (Lithobates catesbeianus in San Juan, Argentina Nuevo registro de rana toro americana (Lithobates catesbeianus en San Juan, Argentina

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Eduardo Sanabria

2011-03-01

Full Text Available We report a new record of Lithobates catesbeianus (American bullfrog from Argentina. L. catesbeianus was first introduced to San Juan Province 11 years ago in Calingasta Department, where the habitat is pre-cordilleran. The new record is for Zonda Department, San Juan Province, in the Monte desert region. Here, L. catesbeianus uses artificial ponds for reproduction and tadpole development. These ponds receive water from an irrigation system that connects the whole agriculture land in the region. The tadpoles use the irrigation canals to move among ponds. We suggest that legislation should be established to prevent future invasions and to achieve sustainable management of the wild American bullfrog populations in San Juan. Prevention of future invasion and management of established populations of this species requires the cooperation of numerous stake holders.Se presenta un nuevo registro de Lithobates catesbeianus (rana toro americana en Argentina. L. catesbeianus fue introducida por primera vez a la provincia de San Juan hace 11 años en el Departamento Calingasta, donde el hábitat es pre-cordillerano. El nuevo registro es para el Departamento Zonda en la provincia de San Juan, en el desierto del Monte. En este sitio, L. catesbeianus usa estanques artificiales para la reproducción y desarrollo del renacuajo. Los estanques reciben agua de un sistema de riego que conecta todas las tierras de la agricultura en la región. Los renacuajos utilizan los canales de riego para moverse entre los estanques. Sugerimos que se establezcan leyes para prevenir invasiones futuras y para lograr un manejo integrado de las poblaciones silvestres de rana toro que se encuentran en San Juan. La prevención de futuras invasiones y el manejo de las poblaciones establecidas de esta especie requieren la cooperación de numerosas entidades tanto gubernamentales como privadas.

Airborne Pesticides as an Unlikely Cause for Population Declines of Alpine Frogs in the Sierra Nevada, California

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...

Influence of Nitrate and Nitrite on Thyroid Hormone Responsive and Stress-Associated Gene Expression in Cultured Rana catesbeiana Tadpole Tail Fin Tissue

Science.gov (United States)

Hinther, Ashley; Edwards, Thea M.; Guillette, Louis J.; Helbing, Caren C.

2012-01-01

Nitrate and nitrite are common aqueous pollutants that are known to disrupt the thyroid axis. In amphibians, thyroid hormone (TH)-dependent metamorphosis is affected, although whether the effect is acceleration or deceleration of this developmental process varies from study to study. One mechanism of action of these nitrogenous compounds is through alteration of TH synthesis. However, direct target tissue effects on TH signaling are hypothesized. The present study uses the recently developed cultured tail fin biopsy (C-fin) assay to study possible direct tissue effects of nitrate and nitrite. Tail biopsies obtained from premetamorphic Rana catesbeiana tadpoles were exposed to 5 and 50 mg/L nitrate (NO3–N) and 0.5 and 5 mg/L nitrite (NO2–N) in the absence and presence of 10 nM T3. Thyroid hormone receptor β (TRβ) and Rana larval keratin type I (RLKI), both of which are TH-responsive gene transcripts, were measured using quantitative real time polymerase chain reaction. To assess cellular stress which could affect TH signaling and metamorphosis, heat shock protein 30, and catalase (CAT) transcript levels were also measured. We found that nitrate and nitrite did not significantly change the level of any of the four transcripts tested. However, nitrate exposure significantly increased the heteroscedasticity in response of TRβ and RLKI transcripts to T3. Alteration in population variation in such a way could contribute to the previously observed alterations of metamorphosis in frog tadpoles, but may not represent a major mechanism of action. PMID:22493607

Influence of nitrate and nitrite on thyroid hormone-responsive and stress-associated gene expression in cultured Rana catesbeiana tadpole tail fin tissue

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Ashley eHinther

2012-04-01

Full Text Available Nitrate and nitrite are common aqueous pollutants that are known to disrupt the thyroid axis. In amphibians, thyroid hormone (TH-dependent metamorphosis is affected, although whether the effect is acceleration or deceleration of this developmental process varies from study to study. One mechanism of action of these nitrogenous compounds is through alteration of TH synthesis. However, direct target tissue effects on TH signalling are hypothesized. The present study uses the recently developed cultured tail fin biopsy (C-fin assay to study possible direct tissue effects of nitrate and nitrite. Tail biopsies obtained from premetamorphic Rana catesbeiana tadpoles were exposed to 5 mg/L and 50 mg/L nitrate (NO3-N and 0.5 mg/L and 5 mg/L nitrite (NO2-N in the absence and presence of 10 nM T3. Thyroid hormone receptor β (TRβ and Rana larval keratin type I (RLKI, both of which are thyroid hormone responsive gene transcripts, were measured using quantitative real time polymerase chain reaction. To assess cellular stress which could affect TH signalling and metamorphosis, heat shock protein 30 (HSP30 and catalase (CAT transcript levels were also measured. We found that nitrate and nitrite did not significantly change the level of any of the four transcripts tested. However, nitrate exposure significantly increased the heteroscedasticity in response of TRβ and RLKI transcripts to T3. Alteration in population variation in such a way could contribute to the previously observed alterations of metamorphosis in frog tadpoles, but may not represent a major mechanism of action.

Amphibian recovery after a decrease in acidic precipitation.

Science.gov (United States)

Dolmen, Dag; Finstad, Anders Gravbrøt; Skei, Jon Kristian

2018-04-01

We here report the first sign of amphibian recovery after a strong decline due to acidic precipitation over many decades and peaking around 1980-90. In 2010, the pH level of ponds and small lakes in two heavily acidified areas in southwestern Scandinavia (Aust-Agder and Østfold in Norway) had risen significantly at an (arithmetic) average of 0.14 since 1988-89. Parallel with the general rise in pH, amphibians (Rana temporaria, R. arvalis, Bufo bufo, Lissotriton vulgaris, and Triturus cristatus) had become significantly more common: the frequency of amphibian localities rose from 33% to 49% (n = 115), and the average number of amphibian species per locality had risen from 0.51 to 0.88. In two other (reference) areas, one with better buffering capacity (Telemark, n = 21) and the other with much less input of acidic precipitation (Nord-Trøndelag, n = 106), there were no significant changes in pH or amphibians.

'Man and biosphere' - studies of the Sikkim Himalayas. Pt. 5. Acute toxicity of selected heavy metals on the tadpoles of Rana hexadactyla

Energy Technology Data Exchange (ETDEWEB)

Khangarot, B S; Sehgal, A; Bhasin, M K

1985-01-01

The toxicity of different heavy metals as mercury, cadmium, lead, arsenic and zinc was tested on tadpoles of Rana hexadactyla. The rank order of the toxicity was determined. The results are briefly discussed.

Cuando un príncipe besa a una rana: ¡Sorpresa! Una propuesta didáctica desde la homosexualidad

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José Antonio Jódar Sánchez

2017-11-01

Full Text Available Resumen: En esta propuesta didáctica, utilizamos el álbum ilustrado como herramienta para la enseñanza de contenido lingüístico, así como valores sociales y cívicos a un grupo de estudiantes de ELE de nivel A2. Utilizamos el álbum ilustrado El día de la rana roja que narra la historia de dos príncipes que se enamoran y adoptan a una niña huérfana. Estructuramos nuestra propuesta en cuatro fases (introducción, comprensión, consolidación, resignificación, de las cuáles las dos últimas son las dos que más desarrollamos. Planteamos una entrevista a la rana del cuento, un teatro con marionetas, y el dibujo del mapa del reino como actividades de introducción. En la fase de comprensión se sugieren actividades de léxico y gramática sencillas, tratando, por ejemplo, los tiempos de presente y futuro. En la fase de consolidación, el profesor tiene la opción de realizar el taller del adivinador de sueños o la puesta en escena de declaraciones de amor entre animales. Finalmente, para la fase de resignificación, se cuestiona por qué el rey y la reina cambian el vestido por unos pantalones al averiguar que su hijo se casará con un chico. Palabras clave: Homosexualidad, español como lengua extranjera, álbum ilustrado, El día de la rana roja.   Abstract: This teaching material is based on the picture book El día de la rana roja, the story of a prince who marries another man and together adopt an orphan child. It is targeted to students of Spanish as a foreign language of any country, including the United States, with an A2 level. Picture books are useful tools to teach, not only language and grammar, but also civility and good manners in society. The proposal is divided into four phases (introduction, comprehension, consolidation, and intellectual challenge, the latter of which are explained in detail. For the introduction phase, we propose interviewing the frog in the story, having a puppet role play narrating the story, and

Water velocity tolerance in tadpoles of the foothill yellow-legged frog (Rana boylii): Swimming performance, growth, and survival

Science.gov (United States)

S. Kupferberg; A. Lind; V. Thill; S. Yarnell

2011-01-01

We explored the effects of large magnitude flow fluctuations in rivers with dams, commonly referred to as pulsed flows, on tadpoles of the lotic-breeding Foothill Yellow-legged Frog, Rana boylii. We quantified the velocity conditions in habitats occupied by tadpoles and then conducted experiments to assess the tolerance to values at the upper limit...

Accelerated hatching of southern leopard frog (Rana sphenocephala) eggs in response to the presence of a crayfish Procambarus nigrocinctus predator

Science.gov (United States)

Daniel Saenz; James B. Johnson; Cory K. Adams; Gage H. Dayton

2003-01-01

Phenotypic plasticity, such as morphological and behavioral changes in response to predators, is common in larval anurans. Less is known about inducible defenses in the embryonic stages of development. We investigated the predation risk imposed by crayfish (Procambarus nigrocinctus) on southern leopard frog (Rana sphenocephala)...

A new gorgoderid species of the urinary bladder of Rana zweifeli from Michoacán, Mexico Una nueva especie de gorgodérido de la vejiga urinaria de Rana zweifeli de Michoacán, México

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Rosario Mata-López

2006-12-01

Full Text Available Gorgoderina tarascae n. sp. is described from the urinary bladder of Rana zweifeli, from Cutzaróndiro, Michoacán, Mexico. Gorgoderina tarascae differs from the other species of the genus by possessing the following combination of characters: follicular vitelline glands, arranged in two clusters of 4-7 follicles dorsal to the ovary, compact and smooth reproductive organs situated far from each other and from the acetabulum, suckers close to each other, and a slender, spindle shaped body with a flexed position due to the situation of the acetabulum.Gorgoderina tarascae n. sp. se describe como parásita de la vejiga urinaria de Rana zweifeli de Cutzaróndiro, Michoacán, México. Gorgoderina tarascae difiere del resto de las especies del género por la siguiente combinación de características: posee glándulas vitelógenas arregladas en dos racimos de 4-7 folículos situados dorsalmente al ovario, órganos reproductivos compactos y de bordes lisos, muy separados entre si y con respecto del acetábulo, ventosas cercanas una de la otra y cuerpo delgado, en forma de huso y flexionado debido a la posición del acetábulo.

Infestación por esparganos en ranas del genero Pristimantis (Anura, Strabomantidae del Perú

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Luis A. Gomez-Puerta

2011-05-01

Full Text Available En el presente estudio, reportamos el parasitismo por esparganos del cestode Spirometra sp. en los anfibios: Pristimantis nephophilus y Pristimantis rhodostichus, provenientes del departamento de San Martin, Perú. Tres estructuras filiformes localizadas a nivel subcutáneo, fueron colectadas e identificadas como esparganos. El hallazgo de este metacestode constituye el primer registro en anfibios del Perú y demuestra que las ranas P. nephophilus y P. rhodostichus son nuevos hospederos intermediarios para Spirometra sp.

Movement ecology and seasonal distribution of mountain yellow-legged frogs, Rana muscosa, in a high-elevation Sierra Nevada basin.

Science.gov (United States)

K.L. Pope; K.R. Matthews

2001-01-01

Movement ecology and seasonal distribution of mountain yellow-legged frogs (Rana muscosa) in Dusy Basin (3470 m), Kings Canyon National Park, California, were characterized using passive integrated transponder (PIT) surveys and visual encounter surveys. We individually PIT-tagged 500 frogs during the summers of 1997 and 1998 and monitored these individuals during seven...

Effects of agricultural pesticides on the immune system of Xenopus laevis and Rana pipiens

International Nuclear Information System (INIS)

Christin, M.S.; Menard, L.; Gendron, A.D.; Ruby, S.; Cyr, D.; Marcogliese, D.J.; Rollins-Smith, L.; Fournier, M.

2004-01-01

Over the last 30 years, there have been mass declines in diverse geographic locations among amphibian populations. Multiple causes have been suggested to explain this decline. Among these, environmental pollution is gaining attention. Indeed, some chemicals of environmental concern are known to alter the immune system. Given that amphibians are frequently exposed to agricultural pesticides, it is possible that these pollutants alter their immune system and render them more susceptible to different pathogens. In this study, we exposed two frog species, Xenopus laevis and Rana pipiens, for a short period of time to a mixture of pesticides (atrazine, metribuzine, endosulfan, lindane, aldicarb and dieldrin) representative in terms of composition and concentrations to what it is found in the environment of the southwest region of the province of Quebec. The pesticides were known to be present in surface water of many tributaries of the St. Lawrence River (Quebec, Canada). Our results demonstrate that the mixture of pesticides could alter the cellularity and phagocytic activity of X. laevis and the lymphocyte proliferation of R. pipiens. Taken together, these results indicate that agricultural pesticides can alter some aspects of the immune response in frogs and could contribute to their global decline by rendering them more susceptible to certain infections

Effects of agricultural pesticides on the immune system of Xenopus laevis and Rana pipiens

Energy Technology Data Exchange (ETDEWEB)

Christin, M.S.; Menard, L.; Gendron, A.D.; Ruby, S.; Cyr, D.; Marcogliese, D.J.; Rollins-Smith, L.; Fournier, M

2004-03-30

Over the last 30 years, there have been mass declines in diverse geographic locations among amphibian populations. Multiple causes have been suggested to explain this decline. Among these, environmental pollution is gaining attention. Indeed, some chemicals of environmental concern are known to alter the immune system. Given that amphibians are frequently exposed to agricultural pesticides, it is possible that these pollutants alter their immune system and render them more susceptible to different pathogens. In this study, we exposed two frog species, Xenopus laevis and Rana pipiens, for a short period of time to a mixture of pesticides (atrazine, metribuzine, endosulfan, lindane, aldicarb and dieldrin) representative in terms of composition and concentrations to what it is found in the environment of the southwest region of the province of Quebec. The pesticides were known to be present in surface water of many tributaries of the St. Lawrence River (Quebec, Canada). Our results demonstrate that the mixture of pesticides could alter the cellularity and phagocytic activity of X. laevis and the lymphocyte proliferation of R. pipiens. Taken together, these results indicate that agricultural pesticides can alter some aspects of the immune response in frogs and could contribute to their global decline by rendering them more susceptible to certain infections.

Rangewide phylogeography and landscape genetics of the Western U.S. endemic frog Rana boylii (Ranidae): Implications for the conservation of frogs and rivers

Science.gov (United States)

Lind, A.J.; Spinks, P.Q.; Fellers, G.M.; Shaffer, H.B.

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 and ND2 fragments for 77 individuals from 34 localities using phylogenetic and population genetic analyses. We constructed gene trees using maximum likelihood and Bayesian inference, and quantified genetic variance (using AMOVA and partial Mantel tests) within and among hydrologic regions and river basins. Several moderately supported, geographically-cohesive mtDNA clades were recovered for R. boylii. While genetic variation was low among populations in the largest, most inclusive clade, samples from localities at the edges of the geographic range demonstrated substantial genetic divergence from each other and from more central populations. Hydrologic regions and river basins, which represent likely dispersal corridors for R. boylii, accounted for significant levels of genetic variation. These results suggest that both rivers and larger hydrologic and geographic regions should be used in conservation planning for R. boylii. ?? 2010 US Government.

Linking the distribution of an invasive amphibian (Rana catesbeiana) to habitat conditions in a managed river system in northern California.

Science.gov (United States)

Terra Fuller; Karen Pope; Donald Ashton; Hartwell Welsh

2010-01-01

Extensive modifications of river systems have left floodplains some of the most endangered ecosystems in the world and made restoration of these systems a priority. Modified river ecosystems frequently support invasive species to the detriment of native species. Rana catesbeiana (American bullfrog) is an invasive amphibian that thrives in modified...

Cadmium pollution and amphibians--Studies in tadpoles of Rana limnocharis.

Science.gov (United States)

Patar, Arabinda; Giri, Anirudha; Boro, Freeman; Bhuyan, Krishna; Singha, Utsab; Giri, Sarbani

2016-02-01

Cadmium is released into the environment in increasing amounts from different natural and anthropogenic activities contaminating the aquatic habitats. Amphibian tadpoles develop in water and hence are likely to be adversely affected by cadmium present in the aquatic environment. We have studied the toxic and genotoxic effects of CdCl2 on the tadpoles of Rana limnocharis. CdCl2 in the concentration range between 0.1 and 0.4 mg/L induced significant mortality in R. limnocharis tadpoles in a dose and time dependent manner. The 10-day LC50 which has more ecological relevance was far less than the 24-h LC50. Tadpoles exposed to CdCl2 metamorphosed at an early age possibly as a survival strategy to move out of the stressful environment. The body weight of the CdCl2 exposed animals at metamorphosis was lower compared to the control individuals which may affect survival and reproductive fitness in adult life. Besides, the average body length of the metamorphosed individuals in the CdCl2 exposed group was higher than the control group. CdCl2 was found to be genotoxic in micronucleus test and comet assay. The ambient concentration of Cd could reach up to 60 μg/L or more. Exposure to 18.5 μg/L of CdCl2 (1% of 24-h LC50) induced significant increase in DNA strand breaks as compared to the control. The present findings demonstrate that presence of cadmium in the aquatic environment can significantly alter the life history traits and cause DNA damage in amphibians and hence, could contribute towards their population decline. Copyright © 2015 Elsevier Ltd. All rights reserved.

New species of Oswaldocruzia (Nematoda: Molineoidae), new species of Rhabdias (Nematoda: Rhabdiasidae), and other helminths in Rana cf. forreri (Anura: Ranidae) from Costa Rica.

Science.gov (United States)

Bursey, Charles R; Goldberg, Stephen R

2005-06-01

Oswaldocruzia costaricensis n. sp. (Strongylida: Molineidae) from the intestines and Rhabdias savagei n. sp. (Rhabditida: Rhabdiasidae) from the lungs of Rana cf. forreri (Anura: Ranidae) are described and illustrated. Oswaldocruzia costaricensis represents the 77th species assigned to the genus and differs from the other Neotropical species in the genus by possessing a Type II bursa and long cervical alae. Rhabdias savagei represents the 47th species assigned to the genus and differs from other Neotropical species in the genus by possession of 4 lips and a postequatorial vulva. Rana cf. forreri was also found to harbor the trematodes, Haematoloechus parcivitellarius and Megalodiscus temperatus, the nematodes, Aplectana incerta, Aplectana itzocanensis, Cosmocerca podicipinus, Foleyellides striatus, Subulascaris falcaustriformis, and a larva of the nematode Brevimulticaecum sp. Cosmocerca panamaensis is considered to be a synonym of Cosmocerca podicipinus.

Choosy females and indiscriminate males: mate choice in mixed populations of sexual and hybridogenetic water frogs (Rana lessonae, Rana esculenta)

OpenAIRE

Engeler, B; Reyer, H U

2001-01-01

For several decades, behavioral ecologists have studied the effects of the environment on the behavior of individuals; but only fairly recently they have started to ask the reverse question: how do the behavioral strategies of individuals affect the composition and dynamics of populations and communities? Although intuitively obvious, this feedback from individual to higher levels is difficult to demonstrate, except in systems with exceptionally fast and marked responses of the populations to...

Comparative microhabitat characteristics at oviposition sites of the California red-legged frog (Rana draytonii)

Science.gov (United States)

Alvarez, Jeff A.; Cook, David G.; Yee, Julie L.; van Hattem, Michael G.; Fong, Darren R.; Fisher, Robert N.

2013-01-01

We studied the microhabitat characteristics of 747 egg masses of the federally-threatened Rana draytonii (California red-legged frog) at eight sites in California. our study showed that a broad range of aquatic habitats are utilized by ovipositing R. draytonii, including sites with perennial and ephemeral water sources, natural and constructed wetlands, lentic and lotic hydrology, and sites surrounded by protected lands and nested within modified urban areas. We recorded 45 different egg mass attachment types, although the use of only a few types was common at each site. These attachment types ranged from branches and roots of riparian trees, emergent and submergent wetland vegetation, flooded upland grassland/ruderal vegetation, and debris. eggs were deposited in relatively shallow water (mean 39.7 cm) when compared to maximum site depths. We found that most frogs in artificial pond, natural creek, and artificial channel habitats deposited egg masses within one meter of the shore, while egg masses in a seasonal marsh averaged 27.3 m from the shore due to extensive emergent vegetation. Rana draytonii appeared to delay breeding in lotic habitats and in more inland sites compared to lentic habitats and coastal sites. eggs occurred as early as mid-december at a coastal artificial pond and as late as mid-April in an inland natural creek. We speculate that this delay in breeding may represent a method of avoiding high-flow events and/or freezing temperatures. Understanding the factors related to the reproductive needs of this species can contribute to creating, managing, or preserving appropriate habitat, and promoting species recovery.

Cryptic invasion of Northern Leopard Frogs (Rana pipiens) across phylogeographic boundaries and a dilemma for conservation of a declining amphibian

Science.gov (United States)

O'Donnell, Ryan P.; Drost, Charles A.; Mock, Karen E.

2017-01-01

Anthropogenic introduction of species is a major contributor to loss of biodiversity. Translocations within the range of a species are less frequently recognized, but have the potential for negative effects as well. Genetic mixing may lead to loss of local adaptations or further decline through outbreeding depression. These cryptic invasions may be quite difficult to recognize, but genetic tools can be used to recognize and monitor such intraspecific introductions. Conversely, translocations within species can be an important conservation tool to reduce inbreeding depression and replace lost genetic diversity. Thus, cryptic invasions can be either an aid or a hindrance to conservation efforts. We tested for the presence of non-native genotypes and assessed the extent and nature of introgression in populations of Northern Leopard Frog (Rana pipiens) in the southwestern US, where populations have declined to a few remnant populations. The most abundant and diverse complex of populations in the region contained a mitochondrial haplotype that was not native to the western US, probably resulting from the introduction of released pets, laboratory animals, or release during fish stocking. These non-native haplotypes were well integrated into a large complex of ponds and lakes, contributing to high genetic diversity in this area. Logistically, the geographic extent of non-native genetic influence within this population precludes eliminating or controlling the non-native component of this population. We recommend assessing the progress and fate of the introgression over time—along with population fitness parameters—to determine whether this introduction is beneficial or detrimental to population persistence. Meanwhile, translocations from nearby locations with similar environmental conditions have the best prospects for avoiding problems with outbreeding depression in other declining populations and will also most effectively preserve regional genetic diversity.

Extra-intestinal localization of Goussia sp (Apicomplexa) oocysts in Rana dalmatina (Anura: Ranidae), and the fate of infection after metamorphosis

Czech Academy of Sciences Publication Activity Database

Jirků, M.; Modrý, David

2006-01-01

Roč. 70, č. 3 (2006), s. 237-241 ISSN 0177-5103 R&D Projects: GA ČR GA206/03/1544; GA ČR GD524/03/H133 Institutional research plan: CEZ:AV0Z60220518 Keywords : Goussia * Rana * Coccidia Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.509, year: 2006

Shore and off-shore monitoring of Rana Pratap Sagar lake

International Nuclear Information System (INIS)

Verma, P.C.; Roy, Alpana; Hegde, A.G.

2005-01-01

The Rana Pratap Sagar (RPS) is a man made fresh water reservoir on the river Chambal and is located about 65 km away from Kota city in the state of Rajasthan. It is a balancing reservoir between Gandhi Sagar, upstream and Jawahar Sagar, downstream. On the eastern bank of RPS there exist Rajasthan Atomic Power Station (RAPS) Site, comprising of four operating pressurized Heavy Water Reactors (PHWRs) of 220 MWe each. The low level radioactive effluents from RAPS, are released in controlled manner to RPS. On release the effluents undergo dispersion in the aquatic environment of RPS and may reach man through, various pathways. Being fresh water reservoir, considerable emphasis is laid on the aquatic monitoring aspects relating to RPS and downstream reservoirs. This paper presents the monitored levels of radioactivity prevailing in the aquatic samples collected from near shore and off shore locations of RPS. (author)

Efecto de ocho Protocolos de Inducción Hormonal sobre la Reproducción de Ranas Venenosas Dendrobates truncatus (Cope, 1861) en el Parque Recreativo y Zoológico Piscilago

OpenAIRE

J Alexander Franco; Sandra Sarmiento

2012-01-01

La difícil reproducción en cautiverio de ranas del género Dendrobates y su importanciapara la investigación médica y la industria de mascotas, han llevando a través del trafico al declive a sus poblaciones naturales, generando la necesidad de investigar el potencial zootécnico y la conservación de estas especies. Este estudio evaluó el efecto de ocho protocolos de inducción hormonal sobre la reproducción de ranas Dendrobates truncatus, se realizó en el Parque recreativo y zoológico Piscilago ...

Cuervo, rana y tortuga en Gönnersdord : Animales representados raras veces, que han sido dibujados perfectamente

Directory of Open Access Journals (Sweden)

Hannelore Bosinski

2005-01-01

Full Text Available En las placas de pizarra del yacimiento magdaleniense de Gönnersdorf (Renania, Alemania encontramos, junto con muchas otras representaciones, un cuervo, una rana y una tortuga. A pesar de que estos animales han sido representados en raras ocasiones, estas figuras son vivas y con muchos detalles anatómicos. Tomando en consideración que los animales no sirvieron de modelo mientras eran dibujados, estas figuras fueron realizadas tras una observación intensiva y dibujadas por artistas con genio eidético.

Peripheral origins and functional characteristics of vibration-sensitive VIIIth nerve fibers in the frog Rana temporaria

DEFF Research Database (Denmark)

Jøgensen, Morten Buhl; Christensen-Dalsgaard, Jakob

1991-01-01

were studied. 2) Vibration-sensitive fibers were found in both the anterior and posterior branch of the VIIIth nerve. 3) No vibration-sensitive fibers were found in the lagenar nerve. 4) The vibration-sensitive fibers in the posterior branch probably innervated the amphibian papilla and many...... of these fibers also responded to low-frequency sound. 5) The vibration-sensitive fibers in the anterior branch probably innervated the sacculus and the utriculus. 6) Hence, the grassfrog has at least two, and probably three, vibration-sensitive organs in the inner ear. 7) All fibers had V-shaped vibrational...... tuning curves. In the posterior branch best frequencies (BFs) ranged from 10 to 300 Hz, in the anterior branch from 10 to 100 Hz. In the posterior branch spike-rate thresholds at BF ranged from 0.04 to 1.28 cm/s2, in the anterior branch from 0.02 to 1.28 cm/s2. All fibers showed strong synchronization...

Los cromosomas meióticos de la rana arborícola Smilisca baudinii (Anura: Hylidae

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Javier Hernández-Guzmán

2011-03-01

Full Text Available La rana arborícola mexicana Smilisca baudinii, es una especie de rana común en Centroamérica. Sin embargo, la biología y genética de la especie, es pobremente conocida a pesar de su importancia para mantener en equilibrio ecológico las selvas tropicales. Con el propósito de contribuir con el conocimiento biológico de esta especie, establecimos el cariotipo típico en meiosis en especímenes recolectados en Tabasco, México, mediante procedimientos citogenéticos estándares. El estudio, se fundamentó en el análisis de 131 dispersiones cromosómicas en estadio meiótico de dos adultos de la especie (una hembra y un macho. El análisis de las metafases, permitió establecer el número modal haploide de 1n=12 cromosomas bivalentes. La fórmula cromosómica del cariotipo haploide, se integró por 12 cromosomas birrámeos caracterizado por 12 pares de cromosomas bivalentes metacéntricos-submetacéntricos (msm. Los conteos en meiosis, hacen suponer como número diploide de cromosomas a un complemento integrado por 2n=24 cromosomas birrámeos. No fue posible observar presencia de cromosomas sexuales, entre las dispersiones meióticas del espécimen hembra y macho. Los resultados sugieren que la estructura cromosómica de S. baudinii, es compartida ampliamente entre las especies de la familia Hylidae y los cromosomas "B" son estructuras importantes en la diversificación de las especies.

Effects of chronic copper exposure on development and survival in the southern leopard frog (Lithobates [Rana] sphenocephalus).

Science.gov (United States)

Lance, Stacey L; Erickson, Matthew R; Flynn, R Wesley; Mills, Gary L; Tuberville, Tracey D; Scott, David E

2012-07-01

Exposure to environmental contaminants contributes to the global decline of amphibian populations. The impacts of organic contaminants on amphibians are well documented. However, substantially less is known concerning the potential effects of metals on amphibian populations. Copper (Cu) is an essential element, but it can be toxic at concentrations only slightly higher than the normal physiological range. The present study examines the effects of chronic Cu exposure on embryos and larvae of southern leopard frogs, Lithobates (Rana) sphenocephalus. Groups of eggs from multiple clutches were collected from two wetlands and exposed to a range of Cu concentrations (0-150 µg/L) until they reached the free-swimming stage, and then individual larvae were reared to metamorphosis. Higher Cu concentrations significantly reduced embryo survival to the free-swimming stage but did not further reduce survival to metamorphosis. Larval period was affected by Cu treatment, but the clutch from which larvae originated (i.e., parentage) explained a higher proportion of the variation. Embryo survival to hatching varied significantly among clutches, ranging from 42.9 to 79.2%. Measurable levels of Cu were found in larvae with body burdens up to 595 µg Cu/g dry mass in the 100 µg/L treatment, and larval Cu body burdens were higher than in metamorphs. The present study also demonstrated that higher initial egg density ameliorated embryo mortality at higher Cu levels and should be accounted for in future studies. Copyright © 2012 SETAC.

Impacts of weathered tire debris on the development of Rana sylvatica larvae.

Science.gov (United States)

Camponelli, Kimberly M; Casey, Ryan E; Snodgrass, Joel W; Lev, Steven M; Landa, Edward R

2009-02-01

Highway runoff has the potential to negatively impact receiving systems including stormwater retention ponds where highway particulate matter can accumulate following runoff events. Tire wear particles, which contain about 1% Zn by mass, make up approximately one-third of the vehicle derived particulates in highway runoff and therefore may serve as a stressor to organisms utilizing retention ponds as habitat. In this study, we focused on the potential contribution of tire debris to Zn accumulation by Rana sylvatica larvae and possible lethal or sublethal impacts resulting from exposure to weathered tire debris during development. Eggs and larvae were exposed to aged sediments (containing either ZnCl2 or tire particulate matter, both providing nominal concentrations of 1000 mg Zn kg(-1)) through metamorphosis. Water column Zn was elevated in both the ZnCl2 and tire treatments relative to the control treatment, indicating that aging allowed Zn leaching from tire debris to occur. Tissue Zn was also elevated for the ZnCl2 and tire treatments indicating that Zn in the treatments was available for uptake by the amphibians. Exposure to both ZnCl2 and tire treatments increased the time for larvae to complete metamorphosis in comparison with controls. We also observed that the longer the organisms took to complete metamorphosis, the smaller their mass at metamorphosis. Our results indicate that Zn leached from aged tire debris is bioavailable to developing R. sylvatica larvae and that exposure to tire debris amended sediments can result in measurable physiological outcomes to wood frogs that may influence population dynamics.

Impacts of weathered tire debris on the development of Rana sylvatica larvae

Science.gov (United States)

Camponelli, K.M.; Casey, R.E.; Snodgrass, J.W.; Lev, S.M.; Landa, E.R.

2009-01-01

Highway runoff has the potential to negatively impact receiving systems including stormwater retention ponds where highway particulate matter can accumulate following runoff events. Tire wear particles, which contain about 1% Zn by mass, make up approximately one-third of the vehicle derived particulates in highway runoff and therefore may serve as a stressor to organisms utilizing retention ponds as habitat. In this study, we focused on the potential contribution of tire debris to Zn accumulation by Rana sylvatica larvae and possible lethal or sublethal impacts resulting from exposure to weathered tire debris during development. Eggs and larvae were exposed to aged sediments (containing either ZnCl2 or tire particulate matter, both providing nominal concentrations of 1000 mg Zn kg-1) through metamorphosis. Water column Zn was elevated in both the ZnCl2 and tire treatments relative to the control treatment, indicating that aging allowed Zn leaching from tire debris to occur. Tissue Zn was also elevated for the ZnCl2 and tire treatments indicating that Zn in the treatments was available for uptake by the amphibians. Exposure to both ZnCl2 and tire treatments increased the time for larvae to complete metamorphosis in comparison with controls. We also observed that the longer the organisms took to complete metamorphosis, the smaller their mass at metamorphosis. Our results indicate that Zn leached from aged tire debris is bioavailable to developing R. sylvatica larvae and that exposure to tire debris amended sediments can result in measurable physiological outcomes to wood frogs that may influence population dynamics. ?? 2008 Elsevier Ltd.

Predator-induced changes in metabolism cannot explain the growth/predation risk tradeoff.

Directory of Open Access Journals (Sweden)

Ulrich K Steiner

2009-07-01

Full Text Available Defence against predators is usually accompanied by declining rates of growth or development. The classical growth/predation risk tradeoff assumes reduced activity as the cause of these declines. However, in many cases these costs cannot be explained by reduced foraging effort or enhanced allocation to defensive structures under predation risk. Here, we tested for a physiological origin of defence costs by measuring oxygen consumption in tadpoles (Rana temporaria exposed to predation risk over short and long periods of time. The short term reaction was an increase in oxygen consumption, consistent with the "fight-or-flight" response observed in many organisms. The long term reaction showed the opposite pattern: tadpoles reduced oxygen consumption after three weeks exposure to predators, which would act to reduce the growth cost of predator defence. The results point to an instantaneous and reversible stress response to predation risk. This suggests that the tradeoff between avoiding predators and growing rapidly is not caused by changes in metabolic rate, and must be sought in other behavioural or physiological processes.

Hydroperiod and cattle use associated with lower recruitment in an r-selected amphibian with a declining population trend in the Klamath Mountains, California

Science.gov (United States)

Esther M. Cole; Rosemary Hartman; Malcolm P. North

2016-01-01

Recent population declines in amphibians associated with mortality in early life stages highlight the need for a better understanding of the environmental factors related to successful survival to metamorphosis. In our study, we closely examine the relative importance of environmental factors to three stages of recruitment for Cascade frogs (Rana cascadae...

The effects of aquatic oxygen concentration, body size and respiratory behaviour on the stamina of obligate aquatic (Bufo americanus) and facultative air-breathing (Xenopus laevis and Rana berlandieri) anuran larvae.

Science.gov (United States)

Wassersug, R J; Feder, M E

1983-07-01

Larvae of the anurans Rana berlandieri and Xenopus laevis have lungs and can breathe air as well as irrigate buccal and pharyngeal surfaces for aquatic respiration. Larvae of Bufo americanus lack lungs until just before metamorphosis and are obligately aquatic. We examined the relationship between the locomotor stamina (time to fatigue), aquatic oxygen concentration, body size, and respiratory behaviour of swimming larvae of these species, with the following results: Stamina is size-dependent in all three species. Aquatic hypoxia reduces stamina in larvae of all three species, but most conspicuously in Bufo. Breathing air increases stamina in Rana larvae, especially in large animals and under aquatic hypoxia. In contrast to Rana larvae, Xenopus larvae swimming in normoxic water undergo a reduction in stamina when allowed to breathe air. In hypoxic water, aerial respiration moderates the reduction in stamina seen in Xenopus larvae. Branchial irrigation is associated with increased stamina in Xenopus, and is increased under hypoxia and at high swimming velocities. Respiratory demand, buoyancy and the drag associated with branchial irrigation all affect respiratory behaviour in Xenopus larvae. The great amount of interspecific variation in the relationship between respiratory behaviour and stamina reveals the importance of measuring performance directly when attempting to interpret the functional significance of respiratory structures and behaviour.

Biota sediment concentration ratio (CRs-b) for fishes of Rana Pratap Sagar Lake, Rawatbhata

International Nuclear Information System (INIS)

Goyal, S.K.; Srivastava, A.P.; Jain, A.K.; Meenal, Balram; Tiwari, S.N.; Ravi, P.M.; Tripathi, R.M.

2018-01-01

Radionuclides dissolved in water can be adsorbed by bottom/shore sediment transferring it to the deep sediment layers. These adsorbed radionuclides can be remobilized and be available again for uptake by freshwater biota. The biota sediment concentration ratio (CR s-b ) is the ratio of the concentration of a radionuclide in an organism (C b ) on a fresh weight basis to the radionuclide concentration measured in the sediment (C sediment ). Using the data of 137 Cs activity in fish and shore sediment, CR s-b was calculated for fish samples of Rana Pratap Sagar (RPS) Lake, Rawatbhata. This value can be applied in predictive models to calculate radionuclide concentration in fish samples

Parasites of the mink frog (rana septentrionalis) from Minnesota, U.S.A.

Science.gov (United States)

Schotthoefer, Anna M.; Bolek, M.G.; Cole, Rebecca A.; Beasley, Val R.

2009-01-01

Twenty-two mink frogs, Rana septentrionalis, collected from two locations in Minnesota, United States, were examined for helminth and protozoan blood parasites in July 1999. A total of 16 parasite taxa were recovered including 5 larval digenean trematodes, 7 adult digenean trematodes, 3 nematodes, and I Trypanosorna species. Infracommunities were dominated by the digeneans in terms of richness and abundance. In particular, echinostomatid metacercariae in the kidneys of frogs were the most common parasites found, infecting 100% of the frogs and consisting of about 90% of all helminth individuals recovered. Gorgodera amplicava, Gorgoderina multilohata, Haernaroloechus pan'iplexus, Haernatoloechus breviplexus, Cosnwcercoides dukae, and Oswaldocruzia pipiens represent new host records. The survey presented here represents the second known helminth survey of mink frogs conducted in North America. A summary of metazoan parasites reported from mink frogs is included.

BIOMETRIC STUDY TO RANA RIDIBUNDA FROG SPECIES NEARNESS TO TIMISOARA LOCALITY

Directory of Open Access Journals (Sweden)

M. BURA

2007-10-01

Full Text Available Speciality literature provides little informations regarding Rana ridibunda frogbiometry. For supply this gap we studied the size and weight of 54 frogs sampled fromnearby Timişoara area ponds.The mean body lenght was 8,08 ± 0,54 cm for the females and respectively 6,17 ± 0,45cm for the males. Before evisceration on a par females weighted 62,28 ± 12,87 g andthe males 22,46 ± 5,3 g whereas after this action the carcase weighted 43,89 ± 8,91 gin the case of females and respectively 18,45 ± 4,42 g in the case of male lake frog. Themean leg lenght measured 12,59 ± 0,68 cm for female frogs and 9,78 ± 0,66 cm in thecase of male frogs. The hind stylopodium was estimated on a par as 13,23 ± 2,57 g forfemales and 5,33 ± 1,26 g for the males.

Biodiversity and productivity of Rana Patap Sagar lake a thermo-ecological study

International Nuclear Information System (INIS)

Verma, P.C.; Sharma, L.L.

2007-01-01

Rana Pratap Sagar (RPS) in Rajasthan, is a man made fresh water reservoir and is balancing between Gandhi Sagar on upstream and Jawahar sagar on its down stream. On its eastern bank there exists Rawatbhata Site, comprising of multi -nuclear facilities. There are four PHWR units of Rajasthan Atomic Power Station (RAPS) which are in operations, two are under construction and another two are under advanced stage of planning. In addition to nuclear power plants the Site also houses a Heavy Water Plant and other allied facilities such as cobalt facility and waste management facilities. RAPS draws water from RPS lake through a 300 m long conduit pipe located at lake bottom about 20 m below the surface. Duly treated low level radioactive liquid effluents from RAPS facilities are injected to the warmed condenser outlet and then allowed to discharge to RPS in a controlled manner. The warm water is likely to remain at the surface and get mixed with lake water and cooled due to dilutions, evaporation from lake surface and wind currents. The heat release to the RPS lake through condenser outlet may effect the microbiological and water quality parameters, planktonic biodiversity, fish productivity etc. and thus it is imperative to conduct the thermal ecological study to assess the extent of maturation of the water body to identify its present trophic status in terms of eutrophication. This presentation gives the details of thermal ecological studies carried out at Rana Pratap Sagar lake during 2002-2004 under DAE-BRNS project.. The study includes monitoring of several water quality parameters, biological and bacterial parameters and data on thermal stratification in respect of RPS reservoir. The data so obtained were subjected to statistical analysis. The probabilistic and possibilistic approaches have been applied to evaluate ecological risk. The study reveals that there is no adverse effect on RPS water quality owing to receive the warmed effluents from RAPS. Furthermore, it

[The coiled bodies and satellite microbodies of the oocyte nuclei in hibernating Rana temporaria frogs contain actin].

Science.gov (United States)

Tsvetkov, A G; Kvasov, I D; Khaĭtlina, S Iu; Parfenov, V N

1997-01-01

Immunocytochemical analysis of preparation of dispersed nuclei content in oocytes of III-IV stages of oogenesis, in terms of Dumont (1972), from hibernating grass frogs using monoclonal antibodies against actin, revealed two types of intranuclear structures containing this protein: coiled bodies (CB) and satellite microbodies (SM). Staining of these preparations with Rhodamin-phalloidin, known specifically to interact with fibrillar actin, did not reveal it in these structures. Results of our biochemical studies, using protease ESP32 specifically cutting only globular actin, are suggesting that both CB and SM contain globular actin. Gall et al. (1975) proposed that CB may be involved in assembling and sorting of small nuclear RNA for the three main RNA processing pathways: pre-mRNA splicing, pre-rRNA processing, and histone pre-mRNA 3'-end formation. Our finding of actin in CB allows a suggestion on actin involvement in the transport of RNA processing complexes from CB to some actual places where processing of RNA takes place. According to our previous data (Tsvetkov, Parfenov., 1994), SM participate in the karyosphere capsule formation. This process is preceded by SM fusion triggered presumably by actin.

Micronuclei induction in Rana catesbeiana tadpoles by the pyrethroid insecticide lambda-cyhalothrin

Directory of Open Access Journals (Sweden)

Marcela Alejandra Campana

2003-01-01

Full Text Available Pyrethroid lambda-cyhalothrin genotoxicity was evaluated using the micronucleus test in Rana catesbeiana tadpoles. The effects of concentration and exposure time on the micronuclei frequency were studied in blood smears obtained from tadpoles exposed to four concentrations (0.02, 0.1, 0.2 and 0.4 mg/L of the compound for 24, 48, 72 and 96 h and 8, 15, 20 and 30 days. As a positive control, tadpoles were exposed to cyclophosphamide (5 mg/L. The micronucleated cell frequency was expressed per 1,000 cells. R. catesbeiana tadpoles exposed to increasing concentrations of lambda-cyhalothrin showed an increase in the micronuclei frequency in peripheral blood. Tadpoles exposed to cyclophosphamide (CP also showed a significant increase in micronucleated erythrocytes which peaked after 15 days. These results suggest that R. catesbeiana tadpoles may provide a useful model for monitoring water pollution.

A New Locality for Rana ridibunda caralitana Arıkan, 1988 (Anura: Ranidae in the Central Anatolia.

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Dinçer Ayaz

2015-12-01

Full Text Available Orta Anadolu’da Rana ridibunda caralitana Arıkan, 1988 için yeni bir lokalite. Bu çalışmada, Bor (Niğde’dan toplanan 18 (10 ♂♂, 8 ♀♀ ergin ova kurbağası örneği, başta renk-desen olmak üzere yapılan morfolojik analiz sonucunda incelenmiştir. İncelenen örneklerin caralitana formuna ait olduğu anlaşılmıştır. Böylece caralitana’nın dağılış areali genişletilmiştir

Growth and developmental effects of coal combustion residues on Southern Leopard Frog (Rana sphenocephala) tadpoles exposed throughout metamorphosis

Energy Technology Data Exchange (ETDEWEB)

Peterson, J.D.; Peterson, V.A.; Mendonca, M.T. [Auburn University, Auburn, AL (United States). Dept. for Biological Science

2008-09-15

The effects of aquatic deposition of coal combustion residues (CCRs) on amphibian life histories have been the focus of many recent studies. In summer 2005, we raised larval Southern Leopard Frogs, Rana sphenocephala, on either sand or CCR substrate (approximately 1 cm deep within plastic bins) and documented effects of sediment type on oral disc condition, as well as time to, mass at, and total body length at key developmental stages, including metamorphosis (Gosner stages (GS) 37, 42, and 46). We found no significant difference in mortality between the two treatments and mortality was relatively low (eight of 48 in the control group and four of 48 in the CCR group). Ninety percent of exposed tadpoles displayed oral disc abnormalities, while no control individuals displayed abnormalities. Tadpoles raised on CCR-contaminated sediment had decreased developmental rates and weighed significantly less at all developmental stages, on average, when compared to controls. The CCR treatment group was also significantly shorter In length than controls at the completion of metamorphosis (GS 46). Collectively, these findings are the most severe sub-lethal effects noted for any amphibian exposed to CCRs to date. More research is needed to understand how these long term effects may contribute to the dynamics of local amphibian populations.

Interaction of an Introduced Predator with Future Effects of Climate Change in the Recruitment Dynamics of the Imperiled Sierra Nevada Yellow-legged Frog (Rana sierrae)

Science.gov (United States)

I Lacan; Kathleen R. Matthews; K.V. Feldman

2008-01-01

Between-year variation in snowpack (from 20 to 200% of average) and summer rainfall cause large fluctuations in volume of small lakes in the higher elevation (> 3000 m) Sierra Nevada, which are important habitat for the imperiled Sierra Nevada Yellow-legged Frog, Rana sierrae. Climate change (global warming) is predicted to increase these...

Enzymatic regulation of seasonal glycogen cycling in the freeze-tolerant wood frog, Rana sylvatica.

Science.gov (United States)

do Amaral, M Clara F; Lee, Richard E; Costanzo, Jon P

2016-12-01

Liver glycogen is an important energy store in vertebrates, and in the freeze-tolerant wood frog, Rana sylvatica, this carbohydrate also serves as a major source of the cryoprotectant glucose. We investigated how variation in the levels of the catalytic subunit of protein kinase A (PKAc), glycogen phosphorylase (GP), and glycogen synthase (GS) relates to seasonal glycogen cycling in a temperate (Ohioan) and subarctic (Alaskan) populations of this species. In spring, Ohioan frogs had reduced potential for glycogen synthesis, as evidenced by low GS activity and high PKAc protein levels. In addition, glycogen levels in spring were the lowest of four seasonal samples, as energy input was likely directed towards metabolism and somatic growth during this period. Near-maximal glycogen levels were reached by mid-summer, and remained unchanged in fall and winter, suggesting that glycogenesis was curtailed during this period. Ohioan frogs had a high potential for glycogenolysis and glycogenesis in winter, as evidenced by large glycogen reserves, high levels of GP and GS proteins, and high GS activity, which likely allows for rapid mobilization of cryoprotectant during freezing and replenishing of glycogen reserves during thawing. Alaskan frogs also achieved a near-maximal liver glycogen concentration by summer and displayed high glycogenic and glycogenolytic potential in winter, but, unlike Ohioan frogs, started replenishing their energy reserves early in spring. We conclude that variation in levels of both glycogenolytic and glycogenic enzymes likely happens in response to seasonal changes in energetic strategies and demands, with winter survival being a key component to understanding the regulation of glycogen cycling in this species.

Endocrine-disrupting effects and reproductive toxicity of low dose MCLR on male frogs (Rana nigromaculata) in vivo

Energy Technology Data Exchange (ETDEWEB)

Jia, Xiuying; Cai, Chenchen; Wang, Jia; Gao, Nana; Zhang, Hangjun, E-mail: zhanghangjun@gmail.com

2014-10-15

Highlights: • Low-dose MCLR (1 μg/L) elicits a potential ecological effect on amphibian populations. • MCLR can induce abnormal sperm morphologies and activities on male frogs. • MCLR can induce a decrease in serum testosterone and an increase in serum estradiol of male frogs. • MCLR can increase SF-1 protein levels and decrease P450 aromatase levels in the gonads of frogs. - Abstract: Toxic cyanobacterial blooms are potential global threats to aquatic ecosystems and human health. The World Health Organization has set a provisional guideline limit of 1 μg/L microcystin-LR (MCLR) in freshwater. However, MCLR concentrations in several water bodies have exceeded this level. Despite this recommended human safety standard, MCLR-induced endocrine-disrupting effects and reproductive toxicity on male frog (Rana nigromaculata) were demonstrated in this study. Results showed that sperm motility and sperm count were significantly and negatively correlated with exposure time and concentration. By contrast, abnormal sperm rate was positively correlated with both parameters. Ultrastructural observation results revealed abnormal sperm morphologies, vacuoles in spermatogenic cells, cell dispersion, incomplete cell structures, and deformed nucleoli. These results indicated that MCLR could induce toxic effects on the reproductive system of frogs, significantly decrease testosterone content, and rapidly increase estradiol content. Prolonged exposure and increased concentration enhanced the relative expression levels of P450 aromatase and steroidogenic factor 1; thus, endocrine function in frogs was disrupted. This study is the first to demonstrate in vivo MCLR toxicity in the reproductive system of male R. nigromaculata. This study provided a scientific basis of the global decline in amphibian populations.

Endocrine-disrupting effects and reproductive toxicity of low dose MCLR on male frogs (Rana nigromaculata) in vivo

International Nuclear Information System (INIS)

Jia, Xiuying; Cai, Chenchen; Wang, Jia; Gao, Nana; Zhang, Hangjun

2014-01-01

Highlights: • Low-dose MCLR (1 μg/L) elicits a potential ecological effect on amphibian populations. • MCLR can induce abnormal sperm morphologies and activities on male frogs. • MCLR can induce a decrease in serum testosterone and an increase in serum estradiol of male frogs. • MCLR can increase SF-1 protein levels and decrease P450 aromatase levels in the gonads of frogs. - Abstract: Toxic cyanobacterial blooms are potential global threats to aquatic ecosystems and human health. The World Health Organization has set a provisional guideline limit of 1 μg/L microcystin-LR (MCLR) in freshwater. However, MCLR concentrations in several water bodies have exceeded this level. Despite this recommended human safety standard, MCLR-induced endocrine-disrupting effects and reproductive toxicity on male frog (Rana nigromaculata) were demonstrated in this study. Results showed that sperm motility and sperm count were significantly and negatively correlated with exposure time and concentration. By contrast, abnormal sperm rate was positively correlated with both parameters. Ultrastructural observation results revealed abnormal sperm morphologies, vacuoles in spermatogenic cells, cell dispersion, incomplete cell structures, and deformed nucleoli. These results indicated that MCLR could induce toxic effects on the reproductive system of frogs, significantly decrease testosterone content, and rapidly increase estradiol content. Prolonged exposure and increased concentration enhanced the relative expression levels of P450 aromatase and steroidogenic factor 1; thus, endocrine function in frogs was disrupted. This study is the first to demonstrate in vivo MCLR toxicity in the reproductive system of male R. nigromaculata. This study provided a scientific basis of the global decline in amphibian populations

Bone marrow reconstitution of immune responses following irradiation in the leopard frog, Rana pipiens

International Nuclear Information System (INIS)

Ramirez, J.A.; Wright, R.K.; Cooper, E.L.

1983-01-01

The bone marrow of Rana is an important source of cells capable of maintaining individual viability, responding to Concanavalin A (Con A) and producing PFC against sheep erythrocyte (SRBC) antigens. Frog marrow is more effective than the spleen in maintaining life. Radiation destroys the ability of frogs to respond to SRBC immunization (lack of bone marrow and spleen PFC, serum antibody) and bone marrow/spleen cells to respond to Con A, i.e., bone marrow and spleen contain radiation-sensitive cells. Shielding one hind leg during irradiation leads to reconstitution of bone marrow/spleen PFC responses, antibody synthesis and individual viability. Our results suggest that bone marrow is: a) the source of stem cells, and b) the source of mature T- and B- lymphocytes that can recirculate within the immune system

Relationships between leukocytes and Hepatozoon spp. In green frogs, Rana clamitans.

Science.gov (United States)

Shutler, Dave; Smith, Todd G; Robinson, Stephen R

2009-01-01

There are few published data on amphibian leukocyte profiles, and relationships between amphibian leukocytes and parasites are even less well known. Using counts from 35 pairs of blood smears taken 2 days apart, we tested for correlations between leukocyte proportions and infection intensities of Hepatozoon spp. (either Hepatozoon catesbianae or Hepatozoon clamatae) in green frogs (Rana clamitans). On average (SE), we counted 65.4 (1.7) lymphocytes, 14.0 (1.3) neutrophils, 19.3 (1.6) eosinophils, 0.9 (0.1) monocytes, and 0.4 (0.1) basophils per 100 leukocytes. All frogs harbored Hepatozoon spp. (median seven parasites per 100 leukocytes; range 1-250). Significant relationships were not observed between numbers of leukocytes and infection intensities of Hepatozoon spp. Among the possible explanations for these null results are that Hepatozoon spp. is benign, that Hepatozoon spp. is able to evade detection by the immune system, that Hepatozoon spp. is able to manipulate leukocyte investment, or that other unmeasured or undetected parasites were more important in affecting immune response.

Blood and urine physiological values in farm-cultured Rana catesbeiana (Anura: Ranidae in Argentina

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José A Coppo

2005-09-01

Full Text Available A total of 302 samples of healthy farm-cultured Rana catesbeiana specimens (9-21 months-old, 50- 350 g liveweight, 50% each sex from the north-east of Argentina, were analyzed through spectrophotometry, electrophoresis, densitometry, refractometry and microscopy in order to obtain blood and urine normal values. Confidence intervals (pCon el propósito de obtener valores normales sanguíneos y urinarios, 302 muestras de ejemplares sanos de Rana catesbeiana del nordeste argentino (9-21 meses de edad, 50-350 g de peso vivo, 50% de cada sexo, fueron analizados por espectrofotometría, electroforesis, densitometría, refractometría y microscopía. Fueron obtenidos intervalos de confianza (p<0.05 para hematocrito (28.6-31.6%, eritrocitos (0.40-0.44 T/L, VCM (686-732 fL, hemoglobina (6.41-7.20 g/dL, HCM (151-164 pg, CHCM (22.6-24.0%, leucocitos (18.7-22.3 G/L, neutrófilos (58.4-63.4%, linfocitos (23.9-29.8%, monocitos (2.1-3.8%, eosinófilos (4.6-7.0%, basófilos (2.9-4.1%, tiempo de sangría (289-393s, tiempo de coagulación (452- 696s, tiempo de protrombina (76-128s, densidad urinaria (1.0061-1.0089 g/mL, pH urinario (6.38-6.96, fibrinógeno (0.59-0.99 g/dL, proteínas totales (4.19-4.49 g/dL, albúmina (1.49-1.67 g/dL, alfa-1 globulina (0.20-0.24 g/dL, alfa-2 globulina (0.48-0.54 g/dL, beta globulina (0.68-0.77 g/dL, gamma globulina (1.28-1.42 g/dL, relación albúmina/globulinas (0.50-0.58, creatinina (4.09-5.56 mg/L, urea (76.1-92.4 mg/L, ácido úrico (11.5-15.4 mg/L, triglicéridos (0.34-0.52 g/L, colesterol total (0.56-0.67 g/L, C-HDL (0.03-0.05 g/L, C-LDL (0.34-0.44 g/L, alfa lipoproteína (6.01-8.67%, beta lipoproteína (91.3-93.9%, glucosa (0.45-0.54 g/L, Na (116-121 meq/L, K (3.42- 3.81 meq/L, Cl (100-116 meq/L, Ca (7.98-8.61 mg/dL, P (8.31-9.36 mg/dL, Mg (2.26-2.55 mg/dL, Fe (105-178 ug/dL, ALP (144-170 IU/L, ALT (10.0-14.8 IU/L, AST (42.8-53.4 IU/L, GGT (7.8-10.6 IU/L, LDH (99-135 IU/L, CHE (151-185 IU/L y CPK (365-500 IU/L. Algunos

Effects of wetland vs. landscape variables on parasite communities of Rana pipiens: links to anthropogenic factors

Science.gov (United States)

Schotthoefer, Anna M.; Rohr, Jason R.; Cole, Rebecca A.; Koehler, Anson V.; Johnson, Catherine M.; Johnson, Lucinda B.; Beasley, Val R.

2011-01-01

The emergence of several diseases affecting amphibian populations worldwide has prompted investigations into determinants of the occurrence and abundance of parasites in frogs. To understand the spatial scales and identify specific environmental factors that determine risks of parasitism in frogs, helminth communities in metamorphic frogs of the northern leopard frog (Rana pipiens) were examined in relation to wetland and landscape factors at local (1 km) and regional (10 km) spatial extents in an agricultural region of Minnesota (USA) using regression analyses, ordination, and variance partitioning techniques. Greater amounts of forested and woody wetland habitats, shorter distances between woody wetlands, and smaller-sized open water patches in surrounding landscapes were the most consistently positive correlates with the abundances, richness, and diversity of helminths found in the frogs. Wetland and local landscape variables were suggested as most important for larval trematode abundances, whereas local and regional landscape variables appeared most important for adult helminths. As previously reported, the sum concentration of atrazine and its metabolite desethylatrazine, was the strongest predictor of larval trematode communities. In this report, we highlight the additional influences of landscape factors. In particular, our data suggest that anthropogenic activities that have resulted in the loss of the availability and connectivity of suitable habitats in the surrounding landscapes of wetlands are associated with declines in helminth richness and abundance, but that alteration of wetland water quality through eutrophication or pesticide contamination may facilitate the transmission of certain parasite taxa when they are present at wetlands. Although additional research is needed to quantify the negative effects of parasitism on frog populations, efforts to reduce inputs of agrochemicals into wetlands to limit larval trematode infections may be warranted

Use of femur bone density to segregate wild from farmed Dybowski's frog (Rana dybowskii).

Science.gov (United States)

Yang, Shu Hui; Huang, Xiao Ming; Xia, Rui; Xu, Yan Chun; Dahmer, Thomas D

2011-04-15

Wildlife has been utilized by humans throughout history and demand continues to grow today. Farming of wildlife can supplement the supply of wild-harvested wildlife products and, in theory, can reduce pressure on free-ranging populations. However, poached wildlife products frequently enter legal markets where they are fraudulently sold as farmed wildlife products. To effectively close this illegal trade in wild-captured wildlife, there is a need to discriminate wild products from farmed products. Because of the strong market demand for wild-captured frog meat and the resulting strong downward pressure on wild populations, we undertook research to develop a method to discriminate wild from farmed Dybowski's frog (Rana dybowskii) based on femur bone density. We measured femur bone density (D(f)) as the ratio of bone mass to bone volume. D(f) of wild frogs revealed a slightly increasing linear trend with increasing age (R(2)=0.214 in males and R(2)=0.111 in females, p=0.000). Wild males and wild females of age classes from 2 to ≥ 5 years had similar D(f) values. In contrast, 2-year-old farmed frogs showed significantly higher D(f) values (p=0.000) among males (mean D(f)=0.623 ± 0.011 g/ml, n=32) than females (mean D(f)=0.558 ± 0.011 g/ml, n=27). For both sexes, D(f) of wild frogs was significantly higher than that of farmed frogs (p=0.000). Among males, 87.5% (28 of 32 individuals) of farmed frogs were correctly identified as farmed frogs and 86.3% (69 of 80 individuals) of wild frogs were correctly identified as wild frogs. These results suggest that femur bone density is one reliable tool for discriminating between wild and farmed Dybowski's frog. This study also highlights a novel strategy with explicit forensic potential to discriminate wild from captive bred wildlife species. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Peran ILO (International Labour Organization) dalam Menangani Kecelakaan Kerja pada Industri Garmen di Bangladesh Studi Kasus Tragedi Rana Plaza Tahun 2013

OpenAIRE

Pakpahan, Saiman; Tambun, Harry Panduari

2015-01-01

This research aims to determine the role of International Labour Organization (ILO) in dealing with industrial workplace accidents in Bangladesh by focusing on Rana Plaza tragedy in 2013. ILO plays an active role to promote decent work for every man and woman all over the world. Workplace accident is one of many problems usually found in garment industry in Bangladesh. Unsafe structural integrity and fire safety are the factors that cause workplace accidents.This research uses Pluralism Persp...

Lipovitellin-phosvitin crystals with orthorhombic features: thin-section electron microscopy, gel electrophoresis, and microanalysis in teleost and amphibian yolk platelets and a comparison with other vertebrates

International Nuclear Information System (INIS)

Lange, R.H.; Richter, H.P.; Riehl, R.; Zierold, K.; Trandaburu, T.; Magdowski, G.

1983-01-01

Yolk-platelet crystals in the teleosts Pelvicachromis pulcher and Noemacheilus barbatulus and the amphibians Xenopus laevis, Rana temporaria, R. esculenta, and Triturus sp. have been studied by electron diffraction and imaging using a standardized processing (glutaraldehyde-osmium tetroxide fixation, glutaraldehyde-urea embedding, thin-section staining), by X-ray microanalysis, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis of their constituents. The crystal lattice is orthorhombic having. Crystal images in the three axial projections point to the presence of space group P212121 (or an approximation of it since the lipovitellin dimers cannot be fully equivalent in some cases), to differences between the phosvitins of the two teleosts, and to a highly unusual stain exclusion from large crystal constituents interpreted as representing lipovitellin dimers. Microanalysis in ultrathin cryosections and other preparations revealed K and Cl to be the prominent ions in the crystals (and in the superficial layer of the platelet). Gel electrophoresis (including data of cyclostomes) showed considerable molecular variations despite a closely similar crystal architecture, emphasizing a physiological significance of the architecture, which may have remained conserved for nearly 400 million years according to paleontologic views

The postglacial recolonization of Northern Europe by Rana arvalis as revealed by microsatellite and mitochondrial DNA analyses.

Science.gov (United States)

Knopp, T; Merilä, J

2009-02-01

The postglacial history of the moor frog (Rana arvalis) in Northern Europe was investigated with the aid of eight variable microsatellite loci and a 661 bp sequence of the mitochondrial cytochrome b gene. A division between eastern and western mitochondrial lineages was discovered, supporting two recolonization routes to Fennoscandia since the last glacial maximum. This result was corroborated by the microsatellite data, which revealed a contact zone between the two lineages in Northern Sweden. These findings add to the increasing evidence that an intraspecific genetic biodiversity founded on the existence of eastern and western clades is a common element in Fennoscandian fauna and flora.

Hexadactyly case at a Rana kl. esculenta sample from the north-western part of Romania (Short Notes

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Istvan SAS

2006-05-01

Full Text Available At 17 June 2006, in a habitat close to Gherta Mica locality (47°56'0'' N, 23°14'0'' E, Satu-Mare County, Romania we had found a sample of Rana kl. esculenta which presented hexadactyly at both of its posterior feet. The captured sample of edible frog had fully formed extra (sixth toes, with phalanges (bones. The hexadactyly was perfectly symmetrical at both of the posterior feet. At this individual we did not discovered any other malformations, the biometrical characters situating in the variations limits of the other green frogs from the studied habitat. A symmetric hexadacytly can be a result of atavism.

Cardiovascular, respiratory and metabolic responses to temperature and hypoxia of the winter frog Rana catesbeiana

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Rocha P.L.

1997-01-01

Full Text Available The objective of the present study was to determine the effects of hypoxia and temperature on the cardiovascular and respiratory systems and plasma glucose levels of the winter bullfrog Rana catesbeiana. Body temperature was maintained at 10, 15, 25 and 35oC for measurements of breathing frequency, heart rate, arterial blood pressure, metabolic rate, plasma glucose levels, blood gases and acid-base status. Reducing body temperature from 35 to 10oC decreased (P<0.001 heart rate (bpm from 64.0 ± 3.1 (N = 5 to 12.5 ± 2.5 (N = 6 and blood pressure (mmHg (P<0.05 from 41.9 ± 2.1 (N = 5 to 33.1 ± 2.1 (N = 6, whereas no significant changes were observed under hypoxia. Hypoxia-induced changes in breathing frequency and acid-base status were proportional to body temperature, being pronounced at 25oC, less so at 15oC, and absent at 10oC. Hypoxia at 35oC was lethal. Under normoxia, plasma glucose concentration (mg/dl decreased (P<0.01 from 53.0 ± 3.4 (N = 6 to 35.9 ± 1.7 (N = 6 at body temperatures of 35 and 10oC, respectively. Hypoxia had no significant effect on plasma glucose concentration at 10 and 15oC, but at 25oC there was a significant increase under conditions of 3% inspired O2. The arterial PO2 and pH values were similar to those reported in previous studies on non-estivating Rana catesbeiana, but PaCO2 (37.5 ± 1.9 mmHg, N = 5 was 3-fold higher, indicating increased plasma bicarbonate levels. The estivating bullfrog may be exposed not only to low temperatures but also to hypoxia. These animals show temperature-dependent responses that may be beneficial since during low body temperatures the sensitivity of most physiological systems to hypoxia is reduced

Food composition of Uludağ frog, Rana macrocnemis Boulenger, 1885 in Uludağ (Bursa, Turkey

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Kerim Çiçek

2011-06-01

Full Text Available Feeding habit and food preferences of Uludağ frog, Rana macrocnemis were studied in 2006 and 2007 in Uludağ (Bursa, Turkey. Stomach contents of 165 (87 males, 58 females, 20 juveniles individuals were analyzed and a total of 2,129 prey items were determined. It was found that the species fed mainly on a variety of invertebrates and especially on insects (96.5%. The most frequently consumed prey items were Coleoptera (62.8%, Diptera (14.4%, and Hymenoptera (9.8%. There was no significant sex- and age-dependent difference in the feeding regime. It appears that the species is feeding less in the breeding period and more in the post-breeding period. It was also evident that there was an increase in the consumption of Coleoptera depending on the elevation.

Screening of a long-term sample set reveals two Ranavirus lineages in British herpetofauna.

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Stephen J Price

Full Text Available Reports of severe disease outbreaks in amphibian communities in mainland Europe due to strains of the common midwife toad virus (CMTV-like clade of Ranavirus are increasing and have created concern due to their considerable population impacts. In Great Britain, viruses in another clade of Ranavirus-frog virus 3 (FV3-like-have caused marked declines of common frog (Rana temporaria populations following likely recent virus introductions. The British public has been reporting mortality incidents to a citizen science project since 1992, with carcasses submitted for post-mortem examination, resulting in a long-term tissue archive spanning 25 years. We screened this archive for ranavirus (458 individuals from 228 incidents using molecular methods and undertook preliminary genotyping of the ranaviruses detected. In total, ranavirus was detected in 90 individuals from 41 incidents focused in the north and south of England. The majority of detections involved common frogs (90% but also another anuran, a caudate and a reptile. Most incidents were associated with FV3-like viruses but two, separated by 300 km and 16 years, involved CMTV-like viruses. These British CMTV-like viruses were more closely related to ranaviruses from mainland Europe than to each other and were estimated to have diverged at least 458 years ago. This evidence of a CMTV-like virus in Great Britain in 1995 represents the earliest confirmed case of a CMTV associated with amphibians and raises important questions about the history of ranavirus in Great Britain and the epidemiology of CMTV-like viruses. Despite biases present in the opportunistic sample used, this study also demonstrates the role of citizen science projects in generating resources for research and the value of maintaining long-term wildlife tissue archives.

Gastrin and Cholecystokinin of the Bullfrog, Rana catesbeiana, Have Distinct Effects on Gallbladder Motility and Gastric Acid Secretion in Vitro

DEFF Research Database (Denmark)

Nielsen, Kaj; Bomgren, Peter; Holmgren, Susanne

1998-01-01

distinct members of the CCK/gastrin family were identified in the bullfrog (Rana catesbeiana), termed CCK and gastrin. Frog gastrin is very similar to CCK in the region defining biological activity. To evaluate whether the two endogenous peptides have distinct properties, their effects were studied...... values are 3.1 and 17.2 nM, respectively. Furthermore, gastrin had a significantly higher efficacy than CCK-8s. Thus, in spite of their close structural resemblance, there are clear differences between the two endogenous peptides in their action on gallbladder and gastric mucosa. It is concluded...

Tracing the genus Sphaerospora: rediscovery, redescription and phylogeny of the Sphaerospora ranae (Morelle, 1929) n. comb. (Myxosporea, Sphaerosporidae), with emendation of the genus Sphaerospora

Czech Academy of Sciences Publication Activity Database

Jirků, Miloslav; Fiala, Ivan; Modrý, David

2007-01-01

Roč. 134, č. 12 (2007), s. 1727-1739 ISSN 0031-1820 R&D Projects: GA ČR GA206/03/1544; GA ČR GD524/03/H133; GA MŠk LC522 Institutional research plan: CEZ:AV0Z60220518 Keywords : Myxosporea * Amphibia * Rana * redescription * phylogeny * SSU rDNA * genus emendation * molecular characteristic Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.081, year: 2007

Molecular cloning and expression patterns of the Vasa gene from Rana nigromaculata (Amphibia: Anura

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Rui Jia

2009-06-01

Full Text Available The Vasa protein is a member of the DEAD (Asp-Glu-Alu-Asp box family of ATP-dependent RNA helicases. The Vasa gene is specifically expressed in germ-line cells of many metazoans and is known to play a critical role in gametogenesis and reproductive regulation. In this paper, we isolate the full length cDNA sequence of the Vasa gene from the frog Rana nigromaculata Hallowell, 1861. The open reading frame (ORF encoding 398 amino acid residues has nine conserved motifs. According to the similarities at the amino acid sequenceythe phylogenetic analysis of Vasa gene was consistent with the evolution relationships from chordates to mammals. Furthermore, the expression pattern analysis of RnVasa mRNA, using the technique of Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR, showed a high level of transcripts in testis, ovary and kidney, whereas little to no signal was detected in other tissues, which suggests that it may play a role during gametogenesis.

Activation of eggs of the frog, Rana nigromaculata Hallowell, after localized UV-irradiation

International Nuclear Information System (INIS)

Sambuichi, Hajime

1981-01-01

To analyze the mode of transmission of the activating stimulus, the change in time course of the 2nd maturation division was examined in eggs of the frog, Rana nigromaculata, which were activated by insemination or by pricking after UV-irradiation at either the animal or the vegetal hemisphere. Irradiation of the animal (UAF) or the vegetal (UVF) hemisphere before insemination retarded the 2nd maturation division in comparison with that in normally fertilized eggs (CF). When the eggs were pricked at the irradiated surface (UAP and UVP, respectively), however, the 2nd maturation division progressed faster than that of CF. The comparison of the velocity of the 2nd maturation division between UAF and UVF, and also between UAP and UVP, showed that the cortical reaction in the vegetal hemisphere was affected by UV-irradiation more severely than that in the animal hemisphere. The results suggested that the quality of the granules or the constituent within the egg cortex might vary according to the regional difference in the egg surface. (author)

Rana computatrix to human language: towards a computational neuroethology of language evolution.

Science.gov (United States)

Arbib, Michael A

2003-10-15

Walter's Machina speculatrix inspired the name Rana computatrix for a family of models of visuomotor coordination in the frog, which contributed to the development of computational neuroethology. We offer here an 'evolutionary' perspective on models in the same tradition for rat, monkey and human. For rat, we show how the frog-like taxon affordance model provides a basis for the spatial navigation mechanisms that involve the hippocampus and other brain regions. For monkey, we recall two models of neural mechanisms for visuomotor coordination. The first, for saccades, shows how interactions between the parietal and frontal cortex augment superior colliculus seen as the homologue of frog tectum. The second, for grasping, continues the theme of parieto-frontal interactions, linking parietal affordances to motor schemas in premotor cortex. It further emphasizes the mirror system for grasping, in which neurons are active both when the monkey executes a specific grasp and when it observes a similar grasp executed by others. The model of human-brain mechanisms is based on the mirror-system hypothesis of the evolution of the language-ready brain, which sees the human Broca's area as an evolved extension of the mirror system for grasping.

Workplace safety in Bangladesh ready-made garment sector: 3 years after the Rana Plaza collapse.

Science.gov (United States)

Barua, Uttama; Ansary, Mehedi Ahmed

2017-12-01

Workplace safety is one of the most important issues in industries worldwide, and is endangered by industrial accidents. Different industrial disasters have resulted in several initiatives worldwide to protect human life and reduce material damage, both nationally and internationally. In Bangladesh, the ready-made garment (RMG) industry is one of the most important export-oriented business sectors, which is facing challenges to ensure workplace safety. The Rana Plaza collapse in Bangladesh is the consequence of such non-compliance. The accident resulted in different local and global initiatives to address the challenges. This article reviews progress and achievement of the initiatives to reduce vulnerability in the Bangladesh RMG industry within 3 years after the deadly accident. In the long run, the challenge is to maintain momentum already created for achieving sustainability in the RMG sector in Bangladesh and maintaining compliance even after the end of support from external partners.

Effects of lead-contaminated sediment on Rana sphenocephala tadpoles

Science.gov (United States)

Sparling, D.W.; Krest, S.K.; Ortiz-Santaliestra, M.

2006-01-01

We exposed larval southern leopard frogs (Rana sphenocephala) to lead-contaminated sediments to determine the lethal and sublethal effects of this metal. Tadpoles were laboratory-raised from early free-swimming stage through metamorphosis at lead concentrations of 45, 75, 180, 540, 2360, 3940, 5520, and 7580 mg/kg dry weight in sediment. Corresponding pore water lead concentrations were 123, 227, 589, 1833, 8121, 13,579, 19,038, and 24,427 ug/L. Tadpoles exposed to lead concentrations in sediment of 3940 mg/kg or higher died within 2 to 5 days of exposure. At lower concentrations, mortality through metamorphosis ranged from 3.5% at 45 mg/kg lead to 37% at 2360 mg/kg lead in sediment. The LC50 value for lead in sediment was 3728 mg/kg (95% CI=1315 to 72,847 mg/kg), which corresponded to 12,539 ug/L lead in pore water (95% CI= 4000 to 35,200 ug/L). Early growth and development were depressed at 2,360 mg/kg lead in sediment (8100 ug/L in pore water) but differences were not evident by the time of metamorphosis. The most obvious effect of lead was its pronounced influence on skeletal development. Whereas tadpoles at 45 mg/kg lead in sediment did not display permanent abnormalities, skeletal malformations increased in frequency and severity at all higher lead concentrations. By 2360 mg/kg, 100% of surviving metamorphs displayed severe spinal problems, reduced femur and humerus lengths, deformed digits, and other bone malformations. Lead concentrations in tissues correlated positively with sediment and pore water concentrations.

Habituation and sensitization of aggression in bullfrogs (Rana catesbeiana): testing the dual-process theory of habituation.

Science.gov (United States)

Bee, M A

2001-09-01

The aggressive response of male bullfrogs (Rana catesbeiana) habituates with repeated broadcasts of acoustic stimuli simulating a new territorial neighbor. The effects of stimulus repetition rate and stimulus intensity on bullfrog aggressive responses were tested in a field experiment designed to test the assumptions of a dual-process theory of habituation. Synthetic advertisement calls were broadcast at 2 repetition rates and 2 intensities in a factorial design. Bullfrogs were more aggressive at the higher stimulus intensity at both repetition rates. Aggressive responses habituated more slowly at the higher stimulus intensity and slower repetition rate compared with other treatments. Several biotic and abiotic factors had small or negligible effects on aggressive responses. Although consistent with the operation of 2 opposing processes, habituation and sensitization, the data provide only partial support for the assumptions of dual-process theory.

Cadmium-induced oxidative stress and apoptosis in the testes of frog Rana limnocharis

Energy Technology Data Exchange (ETDEWEB)

Zhang Hangjun; Cai Chenchen; Shi Cailei; Cao Hui; Han Ziliu [Department of Environmental Sciences, Hangzhou Normal University, Xuelin Road 16, Xiasha Gaojiao Dongqu, Hangzhou, Zhejiang Province, 310036 (China); Jia Xiuying, E-mail: hznujiaxiuying@126.com [Department of Environmental Sciences, Hangzhou Normal University, Xuelin Road 16, Xiasha Gaojiao Dongqu, Hangzhou, Zhejiang Province, 310036 (China)

2012-10-15

Highlights: Black-Right-Pointing-Pointer Cd can cause vacuoles and deformity of the spermatogenic cells in the frog testes. Black-Right-Pointing-Pointer Cd can result in oxidative stress in the frog testes. Black-Right-Pointing-Pointer Cd can induce significantly increase of ROS contents triggered DNA damages in the frog testes. Black-Right-Pointing-Pointer Cd can cause apoptosis in the testes of male R. limnocharis. Black-Right-Pointing-Pointer Apoptosis by Cd in the frog testes is related to Caspase-3, Bax and Bcl-2 genes. - Abstract: This study explored the genetic damage induced by cadmium exposure in the testes of Rana limnocharis. Healthy adult frogs were exposed to 2.5, 5, 7.5, or 10 mg/L of cadmium solution for 14 days. The results showed that exposure to these concentrations increased the levels of reactive oxygen species and malondialdehyde content in the testes, clearly indicating a dose-effect relationship. Moreover, the same dosages of Cd{sup 2+} solution increased glutathione (reduced) content, with the values being significantly different from those observed in the control group (P < 0.01). The comet assay results demonstrated that the DNA damage rate, tail length, and tail moment of samples obtained from frogs exposed to 2.5-7.5 mg/L of cadmium solution significantly increased compared with those of samples obtained from the control group (P < 0.01). These findings suggest that cadmium can induce free radical generation, followed by lipid peroxidation and DNA damage. Ultrastructural observation revealed vacuoles in the spermatogenic cells, cell dispersion, incomplete cell structures, and deformed nucleoli. Moreover, cadmium exposure induced significant down-regulation of Bcl-2 expression and up-regulation of Bax and caspase-3 expressions. Taken together, these data indicate that cadmium can induce testicular cell apoptosis in R. limnocharis. Exploring the effects of cadmium on the mechanism of reproductive toxicity in amphibians will help provide a

Cadmium-induced oxidative stress and apoptosis in the testes of frog Rana limnocharis

International Nuclear Information System (INIS)

Zhang Hangjun; Cai Chenchen; Shi Cailei; Cao Hui; Han Ziliu; Jia Xiuying

2012-01-01

Highlights: ► Cd can cause vacuoles and deformity of the spermatogenic cells in the frog testes. ► Cd can result in oxidative stress in the frog testes. ► Cd can induce significantly increase of ROS contents triggered DNA damages in the frog testes. ► Cd can cause apoptosis in the testes of male R. limnocharis. ► Apoptosis by Cd in the frog testes is related to Caspase-3, Bax and Bcl-2 genes. - Abstract: This study explored the genetic damage induced by cadmium exposure in the testes of Rana limnocharis. Healthy adult frogs were exposed to 2.5, 5, 7.5, or 10 mg/L of cadmium solution for 14 days. The results showed that exposure to these concentrations increased the levels of reactive oxygen species and malondialdehyde content in the testes, clearly indicating a dose–effect relationship. Moreover, the same dosages of Cd 2+ solution increased glutathione (reduced) content, with the values being significantly different from those observed in the control group (P < 0.01). The comet assay results demonstrated that the DNA damage rate, tail length, and tail moment of samples obtained from frogs exposed to 2.5–7.5 mg/L of cadmium solution significantly increased compared with those of samples obtained from the control group (P < 0.01). These findings suggest that cadmium can induce free radical generation, followed by lipid peroxidation and DNA damage. Ultrastructural observation revealed vacuoles in the spermatogenic cells, cell dispersion, incomplete cell structures, and deformed nucleoli. Moreover, cadmium exposure induced significant down-regulation of Bcl-2 expression and up-regulation of Bax and caspase-3 expressions. Taken together, these data indicate that cadmium can induce testicular cell apoptosis in R. limnocharis. Exploring the effects of cadmium on the mechanism of reproductive toxicity in amphibians will help provide a scientific basis accounting for the global population decline in amphibian species.

Short-term occupancy and abundance dynamics of the Oregon spotted frog (Rana pretiosa) across its core range

Science.gov (United States)

Adams, Michael J.; Pearl, Christopher A.; Mccreary, Brome; Galvan, Stephanie

2014-01-01

The Oregon spotted frog (Rana pretiosa) occupies only a fraction of its original range and is listed as Threatened under the Endangered Species Act. We surveyed 93 sites in a rotating frame design (2010–13) in the Klamath and Deschutes Basins, Oregon, which encompass most of the species’ core extant range. Oregon spotted frogs are declining in abundance and probability of site occupancy. We did not find an association between the probability that Oregon spotted frogs disappear from a site (local extinction) and any of the variables hypothesized to affect Oregon spotted frog occupancy. This 4-year study provides baseline data, but the 4-year period was too short to draw firm conclusions. Further study is essential to understand how habitat changes and management practices relate to the status and trends of this species.

Potentially toxic contamination of sediments, water and two animal species in Lake Kalimanci, FYR Macedonia: Relevance to human health

International Nuclear Information System (INIS)

Vrhovnik, Petra; Arrebola, Juan P.; Serafimovski, Todor; Dolenec, Tadej; Šmuc, Nastja Rogan; Dolenec, Matej; Mutch, Elaine

2013-01-01

The objectives of the research were: (1) to examine the concentrations of metals in Vimba melanops and Rana temporaria and (2) to evaluate the potential risks of the contaminated organisms to human health in Makedonska Kamenica region. Analyses identified high levels of Cr, Hg, Ni and Pb in studied animals, which also exceeded their permissible levels in food. In sediment and soil samples, levels of Cd, Cu, Cr, Pb, Zn and As were perceived, while Cd, Cu, Ni, Pb, Se and As were increased in water samples. Results of transfer factor revealed that the examined animals had higher bioaccumulation rate from surrounding waters than from sediments or soils. The accomplished Health Risk Index disclosed that studied animals can have considerably high health risks for inhabitants. Conclusively, they could be considered as highly contaminated with metals and can consequently harm human health, especially children in their early development stages. -- Highlights: •The study merges the accumulation of PTE in animal species, sediments, soils and water. •Correlation between different media and their impact to living organisms'. •Considerably high health risks for inhabitants. -- In the Makedonska Kamenica region had been described several potential sources of exposure therefore exists the potential threat to human health

In vitro and in vivo responses of saccular and caudal nucleus neurons in the grassfrog (Rana temporaria)

DEFF Research Database (Denmark)

Christensen-Dalsgaard, J; Walkowiak, W

1999-01-01

We present results from in vitro and in vivo studies of response properties of neurons in the saccular and caudal nuclei in the frog. In the in vitro studies the saccular nerve of the isolated brain was stimulated with electrical pulses. In the in vivo experiments, the neurons were stimulated...... by dorso-ventral vibrations of the intact animal. We identified six response types: (1) primary-like cells with short latencies and follow repetition rates up to 100 Hz; (2) phasic cells responding only to the first pulse in a train; (3) bursting cells firing several spikes in response to any stimulation......; (4) late responders with very long latencies; (5) integrator cells showing facilitated responses, and (6) inhibitory cells inhibited by saccular nerve stimulation.The cells have comparable sensitivity and frequency characteristics to the primary fibres (BF 10-80 Hz, thresholds from 0.01 cm/s2...

Estimation of the factors determining body size of youngs of the year of Rana temporaria L. before a hibernation

Directory of Open Access Journals (Sweden)

Kutenkov Anatoly Petrovich

2013-10-01

This equation and statistical analysis showed that the year-to-year morphological variability of juvenile frogs by the autumn depends on air temperature, rainfall, and the time of exposition (from the beginning of metamorphosis up to the end of foraging, rather than intrinsic properties of different groups of newly metamorphosed froglets.

Seasonal Variation in the Hepatoproteome of the Dehydration- and Freeze-Tolerant Wood Frog, Rana sylvatica

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Jon P. Costanzo

2011-11-01

Full Text Available Winter’s advent invokes physiological adjustments that permit temperate ectotherms to cope with stresses such as food shortage, water deprivation, hypoxia, and hypothermia. We used liquid chromatography (LC in combination with tandem mass spectrometry (MS/MS quantitative isobaric (iTRAQ™ peptide mapping to assess variation in the abundance of hepatic proteins in summer- and winter-acclimatized wood frogs (Rana sylvatica, a northerly-distributed species that tolerates extreme dehydration and tissue freezing during hibernation. Thirty-three unique proteins exhibited strong seasonal lability. Livers of winter frogs had relatively high levels of proteins involved in cytoprotection, including heat-shock proteins and an antioxidant, and a reduced abundance of proteins involved in cell proliferation, protein synthesis, and mitochondrial function. They also exhibited altered levels of certain metabolic enzymes that participate in the biochemical reorganization associated with aphagia and reliance on energy reserves, as well as the freezing mobilization and post-thaw recovery of glucose, an important cryoprotective solute in freezing adaptation.

Effects of a behavior change campaign on household drinking water disinfection in the Lake Chad basin using the RANAS approach.

Science.gov (United States)

Lilje, Jonathan; Mosler, Hans-Joachim

2018-04-01

Worldwide, an estimated 700 million people rely on unimproved drinking water sources; even more consume water that is not safe to drink. Inadequate drinking water quality constitutes a major risk factor for cholera and other diarrheal diseases around the globe, especially for young children in developing countries. Household water treatment and safe storage systems represent an intermediate solution for settings that lack infrastructure supplying safe drinking water. However, the correct and consistent usage of such treatment technologies rely almost exclusively on the consumer's behavior. This study targeted at evaluating effects of a behavior change campaign promoting the uptake of household drinking water chlorination in communities along the Chari and Logone rivers in Chad. The campaign was based on formative research using health psychological theory and targeted several behavioral factors identified as relevant. A total of 220 primary caregivers were interviewed concerning their household water treatment practices and mindset related to water treatment six months after the campaign. The Risks, Attitudes, Norms, Abilities, and Self-regulation (RANAS) model was used to structure the interviews as the RANAS approach had been used for designing the campaign. Results show significantly higher self-reported drinking water chlorination among participants of the intervention. Significant differences from a control group were identified regarding several behavioral factors. Mediation analysis revealed that the intervention positively affected participants' individual risk estimation for diarrheal disease, health knowledge, perceived efforts and benefits of water treatment, social support strategies, knowledge of how to perform chlorination, and perceived ability to do so. The campaign's effect on water treatment was mainly mediated through differences in health knowledge, changes in norms, and self-efficacy convictions. The findings imply that water treatment behavior

Induction of cytochrome P450-associated monooxygenases in northern leopard frogs, Rana pipiens, by 3,3',4,4',5-pentachlorobiphenyl

Science.gov (United States)

Huang, Y.-W.; Melancon, M.J.; Jung, R.E.; Karasov, W.H.

1998-01-01

Northern leopard frogs (Rana pipiens) were injected intraperitoneally either with a solution of polychlorinated biphenyl (PCB) 126 in corn oil at a concentration of 0.2, 0.7, 2.3 and 7.8 mg/kg body weight or with corn oil alone. Appropriate assay conditions with hepatic microsomes were determined for four cytochrome P450-associated monooxygenases: ethoxyresorufin-O-dealkylase (EROD), methoxy-ROD (MROD), benzyloxy-ROD (BROD) and pentoxy-ROD (PROD). One week after PCB administration, the specific activities of EROD, MROD, BROD and PROD were not elevated at doses ? 0.7 mg/kg (p > 0.05), but were significantly increased at doses ? 2.3 mg/kg compared to the control groups (p leopard frogs.

Evidence for a intimate relationship between mast cells and nerve fibers in the tongue of the frog, Rana esculenta

Energy Technology Data Exchange (ETDEWEB)

Chieffi Baccari, Gabriella; Minucci, Sergio [Naples, II Univ. (Italy). Dipt. di Fisiologia Umana e Funzioni Biologiche Integrate `Filippo Bottazzi`

1997-12-31

Morphological and ultrastructural association of mast cells and nerve fibers were studied in the tongue of the frog Rana esculenta. The number of mast cells in the tongue (253 {+-} 45 / mm{sup 2}) is far the highest of the frog tissue as far as people know. They are distributed throughout the connective tissue among the muscular fibers, near arterioles and venules but predominantly in close association and within the nerves. They are often embedded in the endoneurium within a nerve bundle near to myelinic or unmyelinic fibers and in membrane-to-membrane contact with axonlike processes. Just for the richness of mast cells, the tongue of the frog could represent an useful model to study the relationship between these cells and the peripheral nervous system.

Evidence for a intimate relationship between mast cells and nerve fibers in the tongue of the frog, Rana esculenta

Energy Technology Data Exchange (ETDEWEB)

Chieffi Baccari, Gabriella; Minucci, Sergio [Naples, II Univ. (Italy). Dipt. di Fisiologia Umana e Funzioni Biologiche Integrate ` Filippo Bottazzi`

1998-12-31

Morphological and ultrastructural association of mast cells and nerve fibers were studied in the tongue of the frog Rana esculenta. The number of mast cells in the tongue (253 {+-} 45 / mm{sup 2}) is far the highest of the frog tissue as far as people know. They are distributed throughout the connective tissue among the muscular fibers, near arterioles and venules but predominantly in close association and within the nerves. They are often embedded in the endoneurium within a nerve bundle near to myelinic or unmyelinic fibers and in membrane-to-membrane contact with axonlike processes. Just for the richness of mast cells, the tongue of the frog could represent an useful model to study the relationship between these cells and the peripheral nervous system.

Identification of Elizabethkingia meningoseptica from American bullfrog (Rana catesbeiana farmed in Sabah, Malaysia using PCR method and future management of outbreak

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Zainuri, N.

2013-01-01

Full Text Available Aims: High demand for frog meat in Malaysia especially the American bullfrog (Rana catesbeiana has promoted intensive farming of the animal. However, the farming of American bullfrog is restricted by the occurrence of diseases. This study reports the first isolation of Elizabethkingia meningoseptica from specimens of American bullfrog that suffer from cataract and ‘red-leg’ syndrome.Methodology and Result: The pathogen was isolated from eyes and internal organs (liver, kidney and spleen of thediseased bullfrog specimens. All the bacterial isolates were subjected to phenotypic characterization and antibiotic susceptibility assay, and further identified by using the 16S rDNA sequencing analysis. We designed two pair of specific PCR primers (22-25 mers which are complimentary to the β-lactamase gene in the reference strain ofE. meningoseptica ATCC49470. The result showed all the bacterial isolates shared similar phenotypic characters and antibiotic susceptibility. BLAST analysis of the 16S rDNA sequences indicated that the bacterial isolates had very high sequence homology (100% with E. meningospetica ATCC49470 and E. meningoseptica isolates from mosquito. The two PCR primers were very specific to E. meningoseptica isolates of this study. Conclusion, significance and impact of study: This is the first isolation and characterization of bacterial pathogen, E. meningoseptica in cultured American bullfrog (Rana catesbeina that suffered from eye cataract and ‘red-leg’syndrome in Sabah, Malaysia. It is suspected that one of the possible transmission routes of the bacterial pathogen could be via mosquito bites. The findings suggest that there is urgent requirement for standard guideline of good farming practice to be adopted in frog farms throughout the country. Such a guideline can help in minimizing economic losses, preventing transmission of the zoonotic bacterial pathogen to farm workers, and sustaining the industry in Malaysia andupgrading

Una nueva especie de rana terrestre del género Pristimantis (Amphibia: Craugastoridae, de la Cordillera de Kutukú, Ecuador

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Jorge Brito M.

2013-01-01

Full Text Available Describimos una especie nueva de mediano tamaño (LRC en la hembra 38.7 mm; en machos de 23.8 a 26.4 mm de rana terrestre del género Pristimantis de los bosques sub-tropicales de la Cordillera de Kutukú, del sureste de Ecuador, a elevaciones de 1581-1820 m. Asignamos a Pristimantis almendariz sp. nov., al subgénero Hypodictyon, serie de especies ridens. La nueva especie difiere de otros miembros de la serie ridens por su patrón distintivo con manchas dorsales, membrana timpánica ausente, presencia de tubérculos cónicos agrandados en el párpado, tubérculo inter-orbital prominente, e iris plateado con reticulaciones negras.

Oregon Spotted Frog (Rana pretiosa) movement and demography at Dilman Meadow: Implications for future monitoring

Science.gov (United States)

Chelgren, Nathan D.; Pearl, Christopher A.; Bowerman, Jay; Adams, Michael J.

2007-01-01

From 2001 to 2005, we studied the demography and seasonal movement of Oregon spotted frogs (Rana pretiosa) translocated into created ponds in Dilman Meadow in central Oregon. Our objectives were to inform future monitoring and management at the site, and to elucidate poorly known aspects of the species’ population ecology. Movement rates revealed complementary use of sites seasonally, with one small spring being preferred during winter that was rarely used during the rest of the year. Growth rates were significantly higher in ponds that were not used for breeding, and larger size resulted in significantly higher survival. When variation in survival by size was accounted for there was little variation among ponds in survival. Seasonal estimates of survival were lowest for males during the breeding/post-breeding redistribution period, suggesting a high cost of breeding for males. Overwintering survival for both genders was relatively high. Our study supports others in suggesting Oregon spotted frogs are specific in their overwintering habitat requirements, and that predator-free springs may be of particular value. We suggest that any future monitoring include measures of the rate of pond succession. Demographic monitoring should include metrics of both frog reproduction and survival: counts of egg masses at all ponds during spring, and capture-recapture study of survival in mid and late summer when capture rates are highest. Additional study of early life stages would be particularly useful to broaden our understanding of the species’ ecology. Specifically, adding intensive capture and marking effort after larval transformation in fall would enable a full understanding of the annual life cycle. Complete study of the annual life cycle is needed to isolate the life stages and mechanisms through which Oregon spotted frogs are affected by stressors such as nonnative predators. Dilman Meadow, which lacks many hypothesized stressors, is an important reference for

Terrestrial activity and conservation of adult California red-legged frogs Rana aurora draytonii in coastal forests and grasslands

Science.gov (United States)

Bulger, J.B.; Scott, N.J.; Seymour, R.B.

2003-01-01

The federally threatened California red-legged frog Rana aurora draytonii occupies both aquatic and terrestrial habitats in its adult life stage. The terrestrial activities of this species are not well known and require documentation to assist in the development of appropriate levels of protection under the US Endangered Species Act. We studied the terrestrial activities of radio-tagged red-legged frogs (n = 8-26) inhabiting a coastal watershed in Santa Cruz County, California, during 1997-1998. In particular, we investigated (1) the use of terrestrial habitats by non-migrating adults in relation to season, breeding chronology, and precipitation, and (2) adult migration behavior, including seasonal timing, duration, distances traveled, and the use of corridors. Non-migrating red-legged frogs occupied terrestrial habitats briefly (median = 4-6 days) following infrequent summer rains, but resided nearly continuously on land (median = 20-30 days) from the onset of the winter wet-season until breeding activities commenced 1-2 months later. All of the non-migrating frogs remained within 130 m of their aquatic site of residence (median days), despite frequent and copious rainfall. Adult migration to and from breeding sites occurred from late October through mid-May (wet season). We monitored 25 migration events between aquatic sites that were 200-2800 m apart. Short distance movements ( days, longer movements required up to 2 months. Most migrating frogs moved overland in approximately straight lines to target sites without apparent regard to vegetation type or topography. Riparian corridors were neither essential nor preferred as migration routes. Frogs traveling overland occurred in upland habitats as far as 500 m from water. Approximately 11-22% of the adult population was estimated to migrate to and from breeding sites annually, whereas the bulk of the adult population was resident at these sites. Adequate protection of red-legged frog populations inhabiting

Abundancia relativa y uso de microhábitat de la rana Geobatrachus walkeri (Anura: Strabomantidae en dos hábitats en Sierra Nevada de Santa Marta, Colombia

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Vera Martínez Baños

2011-06-01

Full Text Available La rana Geobatrachus walkeri pertenece a un género monotípico y endémico del área de San Lorenzo, Sierra Nevada de Santa Marta, Colombia. La especie habita en el bosque secundario natural y en una plantación de pino (dominada por Pinus patula. Para comparar la abundancia relativa y el uso del microhábitat en estos dos hábitat y durante los períodos de máxima y mínima precipitación, se distribuyeron aleatoriamente 30 cuadrantes en cada bosque sobre los que se registraron el número de individuos y los microhábitats ocupados. Además se reconocieron otros aspectos de la historia natural mediante muestreo por encuentros casuales (VES, se incluye en los dos hábitats áreas no muestreadas por los cuadrantes. La mayor abundancia de ranas se obtuvo en la plantación de pino y durante la época de lluvias. El microhábitat más usado fue la hojarasca de pino. Geobatrachus walkeri es una especie exitosa en las plantaciones de pino, asociada permanentemente a su hojarasca en donde parece desarrollar todo su ciclo de vida. Las claras modificaciones derivadas de la introducción de las plantaciones de pino en el suelo y el agua, parecen no haber afectado la supervivencia y mantenimiento exitoso de esta especie categorizada como en peligro de extinción.

Genetic structure of the marsh frog (Pelophylax ridibundus) populations in urban landscape

Czech Academy of Sciences Publication Activity Database

Mikulíček, Peter; Pišút, P.

2012-01-01

Roč. 58, č. 5 (2012), s. 833-845 ISSN 1612-4642 Institutional support: RVO:68081766 Keywords : Genetic differentiation * Habitat fragmentation * Microsatellites * Rana ridibunda * Ranidae * Urbanization Subject RIV: EG - Zoology Impact factor: 1.355, year: 2012

Los cromosomas meióticos de la rana arborícola Smilisca baudinii (Anura: Hylidae

Directory of Open Access Journals (Sweden)

Javier Hernández-Guzmán

2011-03-01

Full Text Available La rana arborícola mexicana Smilisca baudinii, es una especie de rana común en Centroamérica. Sin embargo, la biología y genética de la especie, es pobremente conocida a pesar de su importancia para mantener en equilibrio ecológico las selvas tropicales. Con el propósito de contribuir con el conocimiento biológico de esta especie, establecimos el cariotipo típico en meiosis en especímenes recolectados en Tabasco, México, mediante procedimientos citogenéticos estándares. El estudio, se fundamentó en el análisis de 131 dispersiones cromosómicas en estadio meiótico de dos adultos de la especie (una hembra y un macho. El análisis de las metafases, permitió establecer el número modal haploide de 1n=12 cromosomas bivalentes. La fórmula cromosómica del cariotipo haploide, se integró por 12 cromosomas birrámeos caracterizado por 12 pares de cromosomas bivalentes metacéntricos-submetacéntricos (msm. Los conteos en meiosis, hacen suponer como número diploide de cromosomas a un complemento integrado por 2n=24 cromosomas birrámeos. No fue posible observar presencia de cromosomas sexuales, entre las dispersiones meióticas del espécimen hembra y macho. Los resultados sugieren que la estructura cromosómica de S. baudinii, es compartida ampliamente entre las especies de la familia Hylidae y los cromosomas "B" son estructuras importantes en la diversificación de las especies.Meiotic chromosomes of the tree frog Smilisca baudinii (Anura: Hylidae. 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

Behaviors of 14C-butachlor, 14C-chlorpyrifos and 14C-DDT in Rana japonica japonica Guenther

International Nuclear Information System (INIS)

Zhang Yiqiang; Zhong Chuangguang; Zhao Xiaokui; Chen Shunhua

2002-01-01

The research on the behaviors of 14 C-butachlor, 14 C-chlorpyrifos and 14 C-DDT in the frog Rana japonica japonica Guenther was carried out. After administrated per os to the frogs in doses of 380, 347, 363 Bq/g, 14 C-butachlor, 14 C-chlorpyrifos and 14 C-DDT, were distributed respectively to various organs within 24 h with specific accumulating organs as gallbladder, intestine and intestine, relevantly to the pesticides described. Compared to that in gallbladder and intestine, the radioactivity of many organs was extremely low, and this might due to the characters of the pesticides. Analysis of the metabolites of 14 C-DDT in frog at 24 th hr demonstrated that DDT was difficult to be degraded. Most 14 C-butachlor, 14 C-chlorpyrifos 14 C-DDT in liver and fat or ovary of frog was extractable with acetone. However, there were some differences between the pesticides, and the organs as well. And 14 C-butachlor, 14 C-chlorpyrifos or 14 C-DDT were better bound in liver than in fat

Oxidative stress induced in PCB 126-exposed northern leopard frogs, Rana pipiens

Science.gov (United States)

Huang, Y.-W.; Hoffman, D.J.; Karasov, W.H.

2007-01-01

Northern leopard frogs Rana pipiens exposed to PCB 126 (3,3',4,4',5-pentachlorobiphenyl) were examined for hepatic oxidative stress. In a dose-response study, northern leopard frogs were injected intraperitoneally with either PCB 126 in corn oil (0.2, 0.7, 2.3, or 7.8 mg/kg body weight) or corn oil alone. In a time-course study, frogs received 7.8 mg/kg or corn oil alone, and were examined at 1, 2, 3, and 4 wk after dosing. Hepatic concentrations of reduced glutathione (GSH), thiobarbituric acid-reactive substances (TBARS), and total sulfhydryls (total SH), as well as activities of glutathione peroxidase (GSH-P), GSSG reductase (GSSG-R), glucose-6-phosphate dehydrogenase (G-6-PDH), and glutathione S-transferase (GSH-S-T) were measured. In the dose-response experiment, few effects were apparent 1 wk after dosing. In the time-course experiment, significant changes were observed in the 7.8-mg/kg group at 2 wk or more posttreatment. Hepatic concentrations of GSH and TBARS were higher than in corresponding controls at wk 3 and 4; the activities of GSSG-R and GSH-S-T were higher than in controls at wk 2 and 4; and the activity of G-6-PDH was increased at wk 2 and 4. These data collectively indicate that altered glutathione metabolism and oxidative stress occurred and were indicative of both toxicity and induction of protective mechanisms in frogs exposed to PCB. A similar delay in response was reported in fish and may relate to lower metabolic rate and physiological reactions in ectothermic vertebrates

Oxidative stress induced in PCB 126-exposed northern leopard frogs, Rana pipiens.

Science.gov (United States)

Huang, Yue-wern; Hoffman, David J; Karasov, William H

2007-04-15

Northern leopard frogs Rana pipiens exposed to PCB 126 (3,3',4,4',5-pentachlorobiphenyl) were examined for hepatic oxidative stress. In a dose-response study, northern leopard frogs were injected intraperitoneally with either PCB 126 in corn oil (0.2, 0.7, 2.3, or 7.8 mg/kg body weight) or corn oil alone. In a time-course study, frogs received 7.8 mg/kg or corn oil alone, and were examined at 1, 2, 3, and 4 wk after dosing. Hepatic concentrations of reduced glutathione (GSH), thiobarbituric acid-reactive substances (TBARS), and total sulfhydryls (total SH), as well as activities of glutathione peroxidase (GSH-P), GSSG reductase (GSSG-R), glucose-6-phosphate dehydrogenase (G-6-PDH), and glutathione S-transferase (GSH-S-T) were measured. In the dose-response experiment, few effects were apparent 1 wk after dosing. In the time-course experiment, significant changes were observed in the 7.8-mg/kg group at 2 wk or more posttreatment. Hepatic concentrations of GSH and TBARS were higher than in corresponding controls at wk 3 and 4; the activities of GSSG-R and GSH-S-T were higher than in controls at wk 2 and 4; and the activity of G-6-PDH was increased at wk 2 and 4. These data collectively indicate that altered glutathione metabolism and oxidative stress occurred and were indicative of both toxicity and induction of protective mechanisms in frogs exposed to PCB. A similar delay in response was reported in fish and may relate to lower metabolic rate and physiological reactions in ectothermic vertebrates.

Cathelicidins from the bullfrog Rana catesbeiana provides novel template for peptide antibiotic design.

Directory of Open Access Journals (Sweden)

Guiying Ling

Full Text Available Cathelicidins, a class of gene-encoded effector molecules of vertebrate innate immunity, provide a first line of defense against microbial invasions. Although cathelicidins from mammals, birds, reptiles and fishes have been extensively studied, little is known about cathelicidins from amphibians. Here we report the identification and characterization of two cathelicidins (cathelicidin-RC1 and cathelicidin-RC2 from the bullfrog Rana catesbeiana. The cDNA sequences (677 and 700 bp, respectively encoding the two peptides were successfully cloned from the constructed lung cDNA library of R. catesbeiana. And the deduced mature peptides are composed of 28 and 33 residues, respectively. Structural analysis indicated that cathelicidin-RC1 mainly assumes an amphipathic alpha-helical conformation, while cathelicidin-RC2 could not form stable amphipathic structure. Antimicrobial and bacterial killing kinetic analysis indicated that the synthetic cathelicidin-RC1 possesses potent, broad-spectrum and rapid antimicrobial potency, while cathelicidin-RC2 exhibited very weak antimicrobial activity. Besides, the antimicrobial activity of cathelicidin-RC1 is salt-independent and highly stable. Scanning electron microscopy (SEM analysis indicated that cathelicidin-RC1 kills microorganisms through the disruption of microbial membrane. Moreover, cathelicidin-RC1 exhibited low cytotoxic activity against mammalian normal or tumor cell lines, and low hemolytic activity against human erythrocytes. The potent, broad-spectrum and rapid antimicrobial activity combined with the salt-independence, high stability, low cytotoxic and hemolytic activities make cathelicidin-RC1 an ideal template for the development of novel peptide antibiotics.

Helicopter-borne magnetic, electromagnetic and radiometric geophysical survey in the Storforshei area, Rana, Nordland

International Nuclear Information System (INIS)

Rodionov, Alexei; Ofstad, Frode; Tassis, Georgios

2012-01-01

NGU conducted an airborne geophysical survey in Mo i Rana area in July 2012. This report describes and documents the aquisition, processing and visualization of recorded datasets. The geophysical survey results reported herein are 1414 line km. The Geotech Ltd. Hummingbird frequency domain system supplemented by optically pumped cesium magnetometer and 1024 channels RSX-5 spectrometer was used for data aquisition. The survey was flown with 100 m line spacing, line direction of 180 deg North-South (in the west) and 150 deg NorthWest-SouthEast (in the east) with the average speed 96 km/h. The average terrain clearance of the bird was 55 m. Collected data were processed by AR GeoConsulting using Geosoft Oasis Montaj software. Raw total magnetic field data were corrected for diurnal variation and levelled using standard micro levelling algorithm. EM data were filtered and levelled using both automated and manual levelling procedure. Apparent resistivity was calculated from in-phase and quadrature data for each of the five frequencies separately using a homogeneous half space model. Apparent resistivity dataset was levelled and filtered. Radiometric data were processed using standard procedures recommended by International Atomic Energy Association (IAEA). All data were gridded with the cell size of 25 m and presented as shaded relief maps at the scale of 1:25 000.(Author)

Helicopter-borne magnetic, electromagnetic and radiometric geophysical survey in the Storforshei area, Rana, Nordland

Energy Technology Data Exchange (ETDEWEB)

Rodionov, Alexei; Ofstad, Frode; Tassis, Georgios

2012-07-01

NGU conducted an airborne geophysical survey in Mo i Rana area in July 2012. This report describes and documents the aquisition, processing and visualization of recorded datasets. The geophysical survey results reported herein are 1414 line km. The Geotech Ltd. Hummingbird frequency domain system supplemented by optically pumped cesium magnetometer and 1024 channels RSX-5 spectrometer was used for data aquisition. The survey was flown with 100 m line spacing, line direction of 180 deg North-South (in the west) and 150 deg NorthWest-SouthEast (in the east) with the average speed 96 km/h. The average terrain clearance of the bird was 55 m. Collected data were processed by AR GeoConsulting using Geosoft Oasis Montaj software. Raw total magnetic field data were corrected for diurnal variation and levelled using standard micro levelling algorithm. EM data were filtered and levelled using both automated and manual levelling procedure. Apparent resistivity was calculated from in-phase and quadrature data for each of the five frequencies separately using a homogeneous half space model. Apparent resistivity dataset was levelled and filtered. Radiometric data were processed using standard procedures recommended by International Atomic Energy Association (IAEA). All data were gridded with the cell size of 25 m and presented as shaded relief maps at the scale of 1:25 000.(Author)

A frog's-eye view of the landscape : quantifying connectivity for fragmented amphibian populations

NARCIS (Netherlands)

Vos, C.C.

1999-01-01

The spatial habitat requirements are studied for two amphibian species: the tree frog ( Hyla arborea ) and the moor frog ( Rana arvalis ). Fragmentation, the destruction of suitable habitat, results in small fragments that are separated by

The Eurasian eagle-owl (Bubo bubo diet in the Trøndelag region (Central Norway

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Obuch Ján

2016-12-01

Full Text Available Between 2008 and 2015 we collected pellets of the Eurasian eagle-owl (Bubo bubo in the Trøndelag region of central Norway and identified the food remains in these samples. We collected material at 45 sites with samples from a total of 76 nests. Some of the samples were from older and already abandoned nests, but at several sites we also found and collected fresh B. bubo pellets. In total 40,766 items of prey were identified from the osteological material. The most dominant food components were mammals (Mammalia, 25 species, 63.5%. The species representation of birds was very diverse (Aves, more than 150 species, 19.4%. Of amphibians (Amphibia, 1 6.8%, the well-represented species were Rana temporaria. Fish (Pisces, 0.3% were represented rarely, while invertebrates were represented only sporadically (Invertebrata, 0.05%. A special composition was found in the diet spectra of the mammals and birds in the mountainous areas at altitudes between 220-780 m above sea level. The highest proportion of frogs was found in areas in the proximity of the mainland shore. On the northern islands located near the coast a significant proportion of the B. bubo diet consisted of rodents (Rodentia. On the more isolated southern islands of Frøya, Hitra and Storfosna the main prey was sea birds, and of the mammals there were also hedgehogs and rats.

Assessment of thyroid system disruption in Rana pipiens tadpoles chronically exposed to UVB radiation and 4-tert-octylphenol

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Croteau, M.C., E-mail: maxinecroteau@hotmail.com [Centre for Advanced Research in Environmental Genomics (CAREG), Department of Biology, University of Ottawa, 20 Marie Curie Street, Ottawa, Ontario, K1N 6N5 (Canada); Davidson, M., E-mail: mdavi089@uottawa.ca [Centre for Advanced Research in Environmental Genomics (CAREG), Department of Biology, University of Ottawa, 20 Marie Curie Street, Ottawa, Ontario, K1N 6N5 (Canada); Duarte-Guterman, P., E-mail: duarte.paula@gmail.com [Centre for Advanced Research in Environmental Genomics (CAREG), Department of Biology, University of Ottawa, 20 Marie Curie Street, Ottawa, Ontario, K1N 6N5 (Canada); Wade, M., E-mail: mike_wade@hc-sc.gc.ca [Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, 50 Columbine Driveway, Tunney' s Pasture, Ottawa, Ontario, K1A 0K9 (Canada); Popesku, J.T., E-mail: jpopesku@gmail.com [Centre for Advanced Research in Environmental Genomics (CAREG), Department of Biology, University of Ottawa, 20 Marie Curie Street, Ottawa, Ontario, K1N 6N5 (Canada); Wiens, S., E-mail: susannawiens@hotmail.com [Centre for Advanced Research in Environmental Genomics (CAREG), Department of Biology, University of Ottawa, 20 Marie Curie Street, Ottawa, Ontario, K1N 6N5 (Canada); Lean, D.R.S., E-mail: dlean@uottawa.ca [Centre for Advanced Research in Environmental Genomics (CAREG), Department of Biology, University of Ottawa, 20 Marie Curie Street, Ottawa, Ontario, K1N 6N5 (Canada); Trudeau, V.L., E-mail: trudeauv@uottawa.ca [Centre for Advanced Research in Environmental Genomics (CAREG), Department of Biology, University of Ottawa, 20 Marie Curie Street, Ottawa, Ontario, K1N 6N5 (Canada)

2009-11-08

Many studies have considered recent increases in ultraviolet B radiation (UVBR) and endocrine disrupting chemicals polluting the environment as possible contributing factors to the reduction in amphibian populations. It has been demonstrated that exposure of amphibians to estrogenic chemicals or UVBR can affect the timing of larval development and metamorphosis. However, amphibians in the wild are exposed to multiple environmental stressors simultaneously. Therefore, our study examines the effects of UVBR and the estrogenic chemical 4-tert-octylphenol (OP), alone and in combination, on the thyroid system of Rana pipiens tadpoles, which is the main regulator of amphibian metamorphosis. Results demonstrate that thyroid gland histomorphology measurements in Gosner stage 31 tadpoles continuously exposed to UVBR (0.21 W/m{sup 2}) were not different than those measured in animals from the control group. In a separate experiment, tadpoles exposed to environmentally relevant levels of UVBR (0.22 W/m{sup 2}) and/or OP (0.01 nM or 10 nM) exhibited significantly delayed development starting from Gosner stage 29, given that fewer tadpoles developed past stage 29 in these groups. In addition, significantly fewer UVBR-treated tadpoles developed past stage 34 and metamorphosed. Samples were collected from stages 29 and 34 tadpoles for gene expression analysis in tail tissue and measurements of T3 (triiodothyronine) whole body levels (minus tail). UVBR and/or OP exposure did not affect T3 levels in stages 29 and 34 tadpoles. However, a decrease in deiodinase type 2 (D2) or increase in deiodinase type 3 (D3) mRNA levels was observed in groups of tadpoles with slowed developmental rates at those developmental stages. Given that D2 activates and D3 inactivates thyroid hormones (TH), UVBR/OP mediated disruptions in development are likely caused by dysfunctions in the localized metabolism of THs through alterations in the expression of these enzymes in peripheral tissues. This is the

Reproducción de la rana Hyla labialis Reproducción del rana Hvla labialis

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Hunter Alice S.

1962-11-01

Full Text Available 1. Se estudió la ovogénesis en la Hyla labialis para compararla con el mismo proceso en las ranas que viven en países con estaciones climatéricas definidas. Por inyección de glándula pituitaria se pueden obtener huevos fertilizados durante los meses de octubre a junio, y rara vez en los otros meses. 2. Se midieron y se contaron ovocitos enteros en muestras de ovarios maduros, inmaduros y después de la ovulación, Hay ovocitos de todos los tamaños presentes en los ovarios maduros; en los ovarios no maduros, y después de la ovulación hay células de todos los tamaños hasta 1.200 mm. de diámetro. 3. En secciones de ovarios se midió el diámetro de las células y de los núcleos y plaquetas vitelinas. Se estudiaron los cambios citológicos de los núcleos y también del citoplasma. Las plaquetas vitelinas aparecen en células que tienen un diámetro de 0.350 a 0.400 mm, La melanina aparece en ovocitos que tienen 0.700 mm. o más de diámetro. En general, los cambios citológicos son muy semejantes a los descritos por otros investigadores en otras especies. 4. La diferencia más obvia e interesante entre la ovogénesis de la Hyla Iabialis y la de otras especies descritas es la presencia de ovocitos de todos los tamaños y en cantidades grandes en el ovario inmediatamente después de la ovulación. Se piensa que los resultados demuestran que el proceso de ovogénesis sigue durante todos los meses sin detenerse como se hace en países con estaciones climatéricas definidas. 1. Oögenesis of the frog, Hyla labialis has been studied in order to Compare it with the same process in frogs which live in countries with definite climatic seasons. Fertilized eggs can be obtained after pituitary injection during the months of October through June and occasionally during the rest of the year. 2. Whole oöcytes were measured and counted in samples taken from mature ovaries, immature ovaries and ovaries after ovulation had taken place. There are o

Incidence and impact of axial malformations in larval bullfrogs (Rana catesbeiana) developing in sites polluted by a coal-burning power plant

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Hopkins, W.A.; Congdon, J.; Ray, J.K.

2000-01-01

Amphibian malformations have recently received much attention from the scientific community, but few studies have provided evidence linking environmental pollution to larval amphibian malformations in the field. The authors document an increased incidence of axial malformations in bullfrog larvae (Rana catesbeiana) inhabiting two sites contaminated with coal combustion wastes. In the polluted sites, 18 and 37% of larvae exhibited lateral curvatures of the spine, whereas zero and 4% of larvae from two reference sites had similar malformations. Larvae from the most heavily polluted site had significantly higher tissue concentrations of potentially toxic trace elements, including As, Cd, Se, Cu, Cr, and V, compared with conspecifics from the reference sites. In addition, malformed larvae from the cost contaminated site had decreased swimming speeds compared with those of normal larvae from the same site. The authors hypothesize that the complex mixture of contaminants produced by coal combustion is responsible for the high incidence of malformations and associated effects on swimming performance

Composition of Micro-eukaryotes on the Skin of the Cascades Frog (Rana cascadae and Patterns of Correlation between Skin Microbes and Batrachochytrium dendrobatidis

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Jordan G. Kueneman

2017-12-01

Full Text Available Global amphibian decline linked to fungal pathogens has galvanized research on applied amphibian conservation. Skin-associated bacterial communities of amphibians have been shown to mediate fungal skin infections and the development of probiotic treatments with antifungal bacteria has become an emergent area of research. While exploring the role of protective bacteria has been a primary focus for amphibian conservation, we aim to expand and study the other microbes present in amphibian skin communities including fungi and other micro-eukaryotes. Here, we characterize skin-associated bacteria and micro-eukaryotic diversity found across life stages of Cascades frog (Rana cascadae and their associated aquatic environments using culture independent 16S and 18S rRNA marker-gene sequencing. Individuals of various life stages of Cascades frogs were sampled from a population located in the Trinity Alps in Northern California during an epidemic of the chytrid fungus, Batrachochytrium dendrobatidis. We filtered the bacterial sequences against a published database of bacteria known to inhibit B. dendrobatidis in co-culture to estimate the proportion of the skin bacterial community that is likely to provide defense against B. dendrobatidis. Tadpoles had a significantly higher proportion of B. dendrobatidis-inhibitory bacterial sequence matches relative to subadult and adult Cascades frogs. We applied a network analysis to examine patterns of correlation between bacterial taxa and B. dendrobatidis, as well as micro-eukaryotic taxa and B. dendrobatidis. Combined with the published database of bacteria known to inhibit B. dendrobatidis, we used the network analysis to identify bacteria that negatively correlated with B. dendrobatidis and thus could be good probiotic candidates in the Cascades frog system.

Biomimetic agent based modelling using male Frog calling behaviour as a case study

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Jørgensen, Søren V.; Demazeau, Yves; Christensen-Dalsgaard, Jakob

2014-01-01

by individuals to generate their observed population behaviour. A number of existing agent-modelling frameworks are considered, but none have the ability to handle large numbers of time-dependent event-generating agents; hence the construction of a new tool, RANA. The calling behaviour of the Puerto Rican Tree...... Frog, E. coqui, is implemented as a case study for the presentation and discussion of the tool, and results from this model are presented. RANA, in its present stage of development, is shown to be able to handle the problem of modelling calling frogs, and several fruitful extensions are proposed...

Predator mediated selection and the impact of developmental stage on viability in wood frog tadpoles (Rana sylvatica

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Calsbeek Ryan

2011-12-01

Full Text Available Abstract Background Complex life histories require adaptation of a single organism for multiple ecological niches. Transitions between life stages, however, may expose individuals to an increased risk of mortality, as the process of metamorphosis typically includes developmental stages that function relatively poorly in both the pre- and post-metamorphic habitat. We studied predator-mediated selection on tadpoles of the wood frog, Rana sylvatica, to identify this hypothesized period of differential predation risk and estimate its ontogenetic onset. We reared tadpoles in replicated mesocosms in the presence of the larval odonate Anax junius, a known tadpole predator. Results The probability of tadpole survival increased with increasing age and size, but declined steeply at the point in development where hind limbs began to erupt from the body wall. Selection gradient analyses indicate that natural selection favored tadpoles with short, deep tail fins. Tadpoles resorb their tails as they progress toward metamorphosis, which may have led to the observed decrease in survivorship. Path models revealed that selection acted directly on tail morphology, rather than through its indirect influence on swimming performance. Conclusions This is consistent with the hypothesis that tail morphology influences predation rates by reducing the probability a predator strikes the head or body.

The prevalence and risk factors of Post-Traumatic Stress Disorder among workers injured in Rana Plaza building collapse in Bangladesh.

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Fitch, Taylor; Villanueva, Gabriela; Quadir, Mohammad M; Sagiraju, Hari K R; Alamgir, Hasanat

2015-07-01

Prevalence and risk factors of PTSD among injured garment workers who survived a major factory collapse. Survivors receiving treatment or rehabilitation care at one year post event were surveyed, which included Post Traumatic Stress Disorder Checklist Specific version. The respondents consisted of 181 people with a mean age of 27.8 years and a majority had less than high school education (91.2%). Multivariable logistic regression found that the odds of having PTSD was higher among married (OR: 3.2 [95% CI: 1.3-8.0]), those who used to work more than 70 hr/week (OR: 2.4 [1.1-5.3]), workers who used to hold higher job positions (OR: 2.6 [1.2-5.6]) or who had a concussion injury (OR: 3.7 [1.4-9.8]). Among the respondents, 83.4% remained unemployed, and only 57.3% (63 people) reported receiving a quarter or less of what they were promised as compensation. Probable PTSD was prevalent among surviving workers of the Rana Plaza building collapse in Bangladesh. © 2015 Wiley Periodicals, Inc.

Toxic effects of NH4+-N on embryonic development of Bufo gargarizans and Rana chensinensis.

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Deng, Hongzhang; Chai, Lihong; Luo, Pingping; Zhou, Meimei; Nover, Daniel; Zhao, Xiaohong

2017-09-01

Although nitrogen fertilizer is commonly used worldwide, little information is currently available about NH 4 + -N toxicity on amphibians. This study determined the acute and chronic toxic effects of NH 4 + -N on two native Chinese amphibian species (Bufo gargarizans and Rana chensinensis), and compared the negative sensitivity of different embryos to NH 4 + -N. Static renewal aqueous exposures were performed using B. gargarizans and R. chensinensis embryos at Gosner stage 2 over 96 h. In terms of 96 h-LC 50 , B. gargarizans and R. chensinensis embryos had significantly different responses to NH 4 + -N, and the latter was more sensitive to NH 4 + -N than the former. In the chronic toxicity test, exposure to 10 mg L -1 NH 4 + -N or higher significantly decreased the hatching rate of embryos in both species. Significant increases in the abnormality rate of embryos at 50 mg L -1 NH 4 + -N or higher were observed and morphological abnormalities were characterized by axial flexures, yolk sac edema, and hyperplasia in both species. Additionally, the total length of embryos decreased in a dose-dependent manner after exposure to NH 4 + -N. The results indicate that NH 4 + -N exposure can increase abnormality and inhibit the hatching and development of embryos in B. gargarizans and R. chensinensis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Odorous and non-fatal skin secretion of adult wrinkled frog (Rana rugosa is effective in avoiding predation by snakes.

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Yuri Yoshimura

Full Text Available The roles played by nonfatal secretions of adult anurans in the avoidance of predation remain unknown. The adult Wrinkled frog (Rana rugosa has warty skin with the odorous mucus secretion that is not fatal to the snake Elaphe quadrivirgata. We fed R. rugosa or Fejervarya limnocharis, which resembles R. rugosa in appearance and has mucus secretion, to snakes and compared the snakes' responses to the frogs. Compared to F. limnocharis, R. rugosa was less frequently bitten or swallowed by snakes. The snakes that bit R. rugosa spat out the frogs and showed mouth opening (gaping behavior, while the snakes that bit F. limnocharis did not show gaping behavior. We also compared the responses of the snakes to R. rugosa and F. limnocharis secretions. We coated palatable R. japonica with secretions from R. rugosa or F. limnocharis. The frogs coated by R. rugosa secretion were less frequently bitten or swallowed than those coated by F. limnocharis secretion. We concluded that compared to different frog species of similar sizes, the adult R. rugosa was less frequently preyed upon by, and that its skin secretion was effective in avoiding predation by snakes.

Odorous and non-fatal skin secretion of adult wrinkled frog (Rana rugosa) is effective in avoiding predation by snakes.

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Yoshimura, Yuri; Kasuya, Eiiti

2013-01-01

The roles played by nonfatal secretions of adult anurans in the avoidance of predation remain unknown. The adult Wrinkled frog (Rana rugosa) has warty skin with the odorous mucus secretion that is not fatal to the snake Elaphe quadrivirgata. We fed R. rugosa or Fejervarya limnocharis, which resembles R. rugosa in appearance and has mucus secretion, to snakes and compared the snakes' responses to the frogs. Compared to F. limnocharis, R. rugosa was less frequently bitten or swallowed by snakes. The snakes that bit R. rugosa spat out the frogs and showed mouth opening (gaping) behavior, while the snakes that bit F. limnocharis did not show gaping behavior. We also compared the responses of the snakes to R. rugosa and F. limnocharis secretions. We coated palatable R. japonica with secretions from R. rugosa or F. limnocharis. The frogs coated by R. rugosa secretion were less frequently bitten or swallowed than those coated by F. limnocharis secretion. We concluded that compared to different frog species of similar sizes, the adult R. rugosa was less frequently preyed upon by, and that its skin secretion was effective in avoiding predation by snakes.

Nueva especie de rana del género Pristimantis del grupo lacrimosus (Amphibia: Craugastoridae del Parque Nacional Sangay, Ecuador

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Diego Batallas R.

2014-01-01

Full Text Available Describimos una nueva especie de rana terrestre del genero Pristimantis de tamaño mediano (LRC en machos desde 22.18 a 25.13 mm descubierta en los bosques nublados de las estribaciones orientales del Parque Nacional Sangay, al centro oriente de Ecuador, a elevaciones de 2750 m. Asignamos a Pristimantis latericius sp. nov., al grupo Pristimantis lacrimosus, el cual se diferencia del resto de miembros de este grupo por presentar tubérculos prominentes en el parpado superior y una coloración rojo anaranjado en el dorso. Las llamadas son cortas, conformadas por una sola nota y dos bandas armónicas. Importantes levantamientos de información faunística se han venido generando en los últimos años en el Parque Nacional Sangay, sin embargo es necesario incrementar estudios que ayuden a documentar la ecología e historia natural de los anfibios, ya que sin lugar a dudas ayudaran a comprender procesos ecológicos. El descubrimiento de esta y otras nuevas especies en este sector, demuestra su importancia biológica confortando al desarrollo de planes de conservación en este importante Patrimonio Natural de la Humanidad.

Gonadal differentiation in frogs, Rana japonica and R. brevipoda, raised from UV irradiated eggs

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Shirane, T.

1982-01-01

The gonadal differentiation of anurans, Rana japonica and R. brevipoda, was examined in animals raised from eggs which had been irradiated at the vegetal hemisphere with UV (9300 erg/mm2) at the 2-cell stage. In R. japonica about 70% of the larvae at stage I from the pressed and UV-irradiated eggs were germ cell free, but at a stage immediately after metamorphosis all animals had at least some germ cells, although their gonads often were extremely small and poorly differentiated. When male animals matured sexually, many of them had abnormal gonads. However, all of them were shown by artificial means to be capable of fertilization. In the nonpressed and irradiated group, no larvae were germ cell free and the animals immediately after metamorphosis showed nearly normal gonadal differentiation except for the presence of a few degenerate oocytes in the ovaries. The results in R. brevipoda were basically similar to those in R. japonica. In both species, sex ratios were determined at two stages, the first immediately after metamorphosis and the other when the animals matured, as based on gonad morphology and histology and on external sexually dimorphic characters as well. Sex ratios at these two stages in frogs from the pressed and irradiated eggs differed markedly in R. brevipoda. The ratio was normal at metamorphosis but high M/F ratios occurred when animals became mature. That sex reversal took place in this species as well as in R. japonica (in which sex-ratio deviation was not statistically significant) was supported by the sex ratios of the progenies of these supernumerary males

Distribution, structure and projections of the frog intracardiac neurons.

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Batulevicius, Darius; Skripkiene, Gertruda; Batuleviciene, Vaida; Skripka, Valdas; Dabuzinskiene, Anita; Pauza, Dainius H

2012-05-21

Histochemistry for acetylcholinesterase was used to determine the distribution of intracardiac neurons in the frog Rana temporaria. Seventy-nine intracardiac neurons from 13 frogs were labelled iontophoretically by the intracellular markers Alexa Fluor 568 and Lucifer Yellow CH to determine their structure and projections. Total neuronal number per frog heart was (Mean ± SE) 1374 ± 56. Largest collections of neurons were found in the interatrial septum (46%), atrioventricular junction (25%) and venal sinus (12%). Among the intracellularly labelled neurons, we found the cells of unipolar (71%), multipolar (20%) and bipolar (9%) types. Multiple processes originated from the neuron soma, hillock and proximal axon. These processes projected onto adjacent neuron somata and cardiac muscle fibers within the interatrial septum. Average total length of the processes from proximal axon was 348 ± 50 μm. Average total length of processes from soma and hillock was less, 118 ± 27 μm and 109 ± 24 μm, respectively. The somata of 59% of neurons had bubble- or flake-shaped extensions. Most neurons from the major nerves in the interatrial septum sent their axons towards the ventricle. In contrast, most neurons from the ventral part of the interatrial septum sent their axons towards the atria. Our findings contradict to a view that the frog intracardiac ganglia contain only non-dendritic neurons of the unipolar type. We conclude that the frog intracardiac neurons are structurally complex and diverse. This diversity may account for the complicated integrative functions of the frog intrinsic cardiac ganglia. Copyright © 2012 Elsevier B.V. All rights reserved.

Incidence of climate on common frog breeding: Long-term and short-term changes

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Neveu, André

2009-09-01

In Brittany (northwest France), the climate is showing a trend toward warming. This change is increasingly suspected to have a role in driving amphibian decline, but it is very difficult to determine at what level the climate affects the future of species. Recently, some studies have detected some direct effects on breeding phenology and indirect effects on energy allocation. The present study explores some of these effects on the common frog ( Rana temporaria) from 1984 to 2007. The results show two trends: a long-term change in breeding activities and a short-term influence due to the 2003 climatic anomaly. For the period of study, the start of egg-laying shows a precocity that was correlated with thermal conditions during the preceding 40 days as well as milder springs during the previous year. This degree of precocity is currently the highest found in Europe (+26.6 days). As a result of the 2003 heat wave, the clutch mean fecundity in 2004 was smaller than for other years, the fecundity rates were reduced and abortions were numerous (unlike other years). Moreover, young females were the smallest observed in recent years and some females seemed to exhibit a trade-off between fecundity and growth. Before or after egg-laying, female body condition and mean weight of mature ovules were both lower. The year 2005 appears as a transition period before the recovery in 2006-2007. The results show that climate warming endangers the vital rates of the common frog, while the 2003 climatic events seem more detrimental than the long-term warming trend.

Ranalexin. A novel antimicrobial peptide from bullfrog (Rana catesbeiana) skin, structurally related to the bacterial antibiotic, polymyxin.

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Clark, D P; Durell, S; Maloy, W L; Zasloff, M

1994-04-08

Antimicrobial peptides comprise a diverse class of molecules used in host defense by plants, insects, and animals. In this study we have isolated a novel antimicrobial peptide from the skin of the bullfrog, Rana catesbeiana. This 20 amino acid peptide, which we have termed Ranalexin, has the amino acid sequence: NH2-Phe-Leu-Gly-Gly-Leu-Ile-Lys-Ile-Val-Pro-Ala-Met-Ile-Cys-Ala-Val-Thr- Lys-Lys - Cys-COOH, and it contains a single intramolecular disulfide bond which forms a heptapeptide ring within the molecule. Structurally, Ranalexin resembles the bacterial antibiotic, polymyxin, which contains a similar heptapeptide ring. We have also cloned the cDNA for Ranalexin from a metamorphic R. catesbeiana tadpole cDNA library. Based on the cDNA sequence, it appears that Ranalexin is initially synthesized as a propeptide with a putative signal sequence and an acidic amino acid-rich region at its amino-terminal end. Interestingly, the putative signal sequence of the Ranalexin cDNA is strikingly similar to the signal sequence of opioid peptide precursors isolated from the skin of the South American frogs Phyllomedusa sauvagei and Phyllomedusa bicolor. Northern blot analysis and in situ hybridization experiments demonstrated that Ranalexin mRNA is first expressed in R. catesbeiana skin at metamorphosis and continues to be expressed into adulthood.

Ciliates (Protozoa from dried sediments of a temporary pond from Argentina Ciliados (Protozoa de sedimentos secos de una charca temporaria de la Argentina

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Gabriela Cristina Küppers

2009-12-01

Full Text Available Temporary ponds represent special environments that are inhabited by organisms adapted to changing environmental conditions. Ciliates are able to survive complete loss of water in these transient habitats through cyst formation. However, ciliates from the Neotropical region in general have been poorly studied with modern techniques. The main goal of this study is to describe the ciliates in dried sediments of a temporary pond from Buenos Aires Province, Argentina, through sampling efforts that were performed 2003-2005. Soil samples were obtained during drought phases and re wetted in laboratory to establish raw and enriched cultures. Ciliates were then studied both in vivo and after impregnation with protargol. In this study, we present 4 new records for Argentina (Gonostomum affine (Stein, 1859 Sterki, 1878, Stylonychia bifaria (Stokes, 1887 Berger, 1999, Pleurotricha lanceolata (Ehrenberg, 1835 Stein, 1859, Meseres corlissi Petz and Foissner, 1992, 1 for South America (Blepharisma americanum (Suzuki, 1954 Hirshfield, Isquith and Bhandary, 1965, and 2 for the Neotropical Realm (Gonostomum strenuum (Engelmann, 1862 Sterki, 1878, Stylonychia lemnae Ammermann and Schlegel, 1983.Los cuerpos de agua temporarios son ambientes particulares que se encuentran habitados por organismos adaptados a condiciones fluctuantes. Los ciliados son capaces de sobrevivir a la pérdida completa de agua del ambiente gracias a la formación de estructuras de resistencia. Por otra parte, los ciliados de la región Neotropical han sido poco investigados con técnicas modernas. El objetivo de este estudio es referir los ciliados que se desarrollaron a partir de los sedimentos secos de una charca temporaria de la provincia de Buenos Aires, Argentina, en la que se realizaron muestreos durante el período 2003-2005. Las muestras de suelo fueron obtenidas durante las fases de sequía y luego resuspendidas en el laboratorio para realizar cultivos naturales y enriquecidos. Los

Relationships among developmental stage, metamorphic timing, and concentrations of elements in bullfrogs (Rana catesbeiana)

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Snodgrass, J.W.; Hopkins, W.A.; Roe, J.H. [Towson University, Towson, MD (United States). Dept. for Biological Science

2003-07-01

We collected bullfrog (Rana catesbeiana) larvae from a coal combustion waste settling basin to investigate the effects of developmental stage and timing of metamorphosis on concentrations of a series of trace elements in bullfrog tissues. Bullfrogs at four stages of development (from no hind limbs to recently metamorphosed juveniles) and bullfrogs that metamorphosed in the fall or overwintered in the contaminated basin and metamorphosed in the spring were analyzed for whole-body concentrations of Al, V, Cr, Ni, Cu, As, Pb, Cd, Zn, Ag, Sr, and Se. After the effects of dry mass were removed, tissue concentrations of six elements (Al, V, Cr, Ni, Cu, As, and Pb) decreased from the late larval stage through metamorphosis. Decreases in concentrations through metamorphosis ranged from 40% for Cu to 97% for Al. Tissue concentrations of these elements were also similar or higher in spring; Al and Cr concentrations were 34 and 90% higher in the spring, respectively, whereas As, Ni, Cu, and Pb concentrations were {lt} 10% higher. Concentrations of Cd, Se, and Ag varied among seasons but not among stages; Cd and Ag concentrations were 40 and 62% lower, respectively, and Se concentrations were 21% higher in spring. Concentrations of Zn varied only among stages; concentrations decreased gradually through late larval stage and then increased through metamorphosis. Concentrations of Sr varied among stages, but this variation was dependent on the season. Concentrations of Sr were higher in larval stages during the spring, but because concentrations of Sr increased 122% through metamorphosis in the fall and only 22% in the spring, concentrations were higher in fall metamorphs when compared with spring metamorphs. Our results indicate that metamorphosis and season of metamorphosis affects trace element concentrations in bullfrogs and may have important implications for the health of juveniles and the transfer of pollutants from the aquatic to the terrestrial environment.

EXAMINATION OF HABITAT USE AND DISPERSAL OF EXOTIC BULLFROGS AND THEIR POTENTIAL IMPACT ON NATIVE AMPHIBIAN COMMUNITIES IN THE WILLAMETTE VALLEY, OREGON

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Bullfrogs (Rana catesbeiana) are exotic in the west and have been implicated in the decline of western pond turtles and native ranids. Habitat alterations that favor bullfrogs have enhanced populations, particularly in agricultural areas such as the Willamette Valley. I will pres...

Effects of testosterone on contractile properties of sexually dimorphic forelimb muscles in male bullfrogs (Rana catesbeiana, Shaw 1802

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Aaron R. Kampe

2013-07-01

This study examined the effects of testosterone (T on the contractile properties of two sexually dimorphic forelimb muscles and one non-dimorphic muscle in male bullfrogs (Rana catesbeiana, Shaw 1802. The dimorphic muscles in castrated males with testosterone replacement (T+ achieved higher forces and lower fatigability than did castrated males without replaced testosterone (T0 males, but the magnitude of the differences was low and many of the pair-wise comparisons of each muscle property were not statistically significant. However, when taken as a whole, the means of seven contractile properties varied in the directions expected of masculine values in T+ animals in the sexually dimorphic muscles. Moreover, these data, compared with previous data on male and female bullfrogs, show that values for T+ males are similar to normal males and are significantly different from females. The T0 males tended to be intermediate in character between T+ males and females, generally retaining masculine values. This suggests that the exposure of young males to T in their first breeding season produces a masculinizing effect on the sexually dimorphic muscles that is not reversed between breeding seasons when T levels are low. The relatively minor differences in contractile properties between T+ and T0 males may indicate that as circulating T levels rise during breeding season in normal males, contractile properties can be enhanced rapidly to maximal functional levels for breeding success.

Effects of Insecticides on Strawberry Aphid Chaetosiphon fragaefolii (Cockerell on Resistant and Susceptible Strawberry Genotypes

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Slobodan Milenković

2011-01-01

Full Text Available Strawberry aphid, Chaetosiphon fragaefolii (Cockerell, is the most important vector ofstrawberry virus. Breeding of genotypes resistant to this pest is an important preventivecontrol measure, which can be compatible with rational insecticide application. The aimof the paper was to determine effects of dimethoate and deltamethrin on C. fragaefoliipopulations reared on two strawberry genotypes different in susceptibility: susceptiblestrawberry cultivar Čačanska rana and medium resistant hybrid, zf/1/94/96 (Senga Fructarinax Del Norte. Lower toxicity of deltamethrin was observed (laboratory assay as well aslower biological efficacy of dimethoate at lower concentrations (field trial for specimensfrom C. fragaefolii population reared on susceptible strawberry cultivar Čačanska rana.

Chilled frogs are hot: hibernation and reproduction of the Endangered mountain yellow-legged frog Rana muscosa

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Santana, Frank E.; Swaisgood, Ronald R.; Lemm, Jeffrey M.; Fisher, Robert N.; Clark, Rulon W.

2015-01-01

In the face of the sixth great extinction crisis, it is imperative to establish effective breeding protocols for amphibian conservation breeding programs. Captive efforts should not proceed by trial and error, nor should they jump prematurely to assisted reproduction techniques, which can be invasive, difficult, costly, and, at times, counterproductive. Instead, conservation practitioners should first look to nature for guidance, and replicate key conditions found in nature in the captive environment, according to the ecological and behavioral requirements of the species. We tested the effect of a natural hibernation regime on reproductive behaviors and body condition in the Endangered mountain yellow-legged frog Rana muscosa. Hibernation had a clear positive effect on reproductive behavior, manifesting in vocal advertisement signaling, female receptivity, amplexus, and oviposition. These behaviors are critical components of courtship that lead to successful reproduction. Our main finding was that captive R. muscosa require a hibernation period for successful reproduction, as only hibernated females produced eggs and only hibernated males successfully fertilized eggs. Although hibernation also resulted in a reduced body condition, the reduction appeared to be minimal with no associated mortality. The importance of hibernation for reproduction is not surprising, since it is a major component of the conditions that R. muscosa experiences in the wild. Other amphibian conservation breeding programs can also benefit from a scientific approach that tests the effect of natural ecological conditions on reproduction. This will ensure that captive colonies maximize their role in providing genetic reservoirs for assurance and reintroduction efforts.

Exposure to coal combustion residues during metamorphosis elevates corticosterone content and adversely affects oral morphology, growth, and development in Rana sphenocephala

Energy Technology Data Exchange (ETDEWEB)

Peterson, J.D.; Peterson, V.A.; Mendonca, M.T. [Auburn University, Auburn, AL (USA). Dept. of Biological Science

2009-01-15

Coal combustion residues (CCRs) are documented to negatively impact oral morphology, growth, and development in larval amphibians. It is currently unclear what physiological mechanisms may mediate these effects. Corticosterone, a glucocorticoid hormone, is a likely mediator because when administered exogenously it, like CCRs, also negatively influences oral morphology, growth, and development in larval amphibians. In an attempt to identify if corticosterone mediates these effects, we raised larval Southern Leopard Frogs, Rana sphenocephala, on either sand or CCR substrate and documented effects of sediment type on whole body corticosterone, oral morphology, and time to and mass at key metamorphic stages. Coal combustion residue treated tadpoles contained significantly more corticosterone than controls throughout metamorphosis. However, significantly more oral abnormalities occurred early in metamorphosis when differences in corticosterone levels between treatments were minimal. Overall, CCR-treated tadpoles took significantly more time to transition between key stages and gained less mass between stages than controls, but these differences between treatments decreased during later stages when corticosterone differences between treatments were greatest. Our results suggest endogenous increase in corticosterone content and its influence on oral morphology, growth and development is more complex than previously thought.

Experimental Repatriation of Mountain Yellow-legged Frogs (Rana muscosa) in the Sierra Nevada of California

Science.gov (United States)

Fellers, Gary M.; Bradford, David F.; Pratt, David; Wood, Leslie

2008-01-01

In the late 1970s, Rana muscosa (mountain yellow-legged frog) was common in the Tableland area of Sequoia National Park, California where it was possible to find hundreds of tadpoles and adults around many of the ponds and lakes. Surveys in 1993-1995 demonstrated that R. muscosa was absent from more than half of all suitable habitat within the park, including the Tableland area. At that same time, R. muscosa was still common at Sixty Lake Basin, Kings Canyon National Park, 30 km to the northeast. To evaluate the potential causes for the extirpation, we repatriated R. muscosa eggs, tadpoles, subadults, and adult frogs from Sixty Lake Basin to four sites in the Tableland area in 1994 and 1995. We subsequently surveyed each release site and the surrounding area 2 - 3 times per week in 1994-1995, and intermittently in 1996-1997, to monitor the survival of all life history stages, and to detect dispersal of adults and subadults. We also monitored predation, water quality, weather, and water temperature. Our techniques for capturing, holding, transporting, and releasing R. muscosa were refined during the study, and during 1995 resulted in high initial survival rates of all life history stages. Adult frogs were anaesthetized, weighed, measured, tagged, and held in plastic boxes with wet paper towels. Tadpoles were collected and held in fiberglass screen cages set in the water at the edge of a pond. This resulted in relatively natural conditions with less crowding and good water circulation. Frogs, tadpoles, and eggs were placed in Ziploc bags for transport to the Tableland by helicopter. Short-term survival of tadpoles, subadults, and adults was high at all four release sites, tadpoles reached metamorphosis, and adult frogs were still present. However, we detected no evidence of reproduction at three sites (e.g., no new eggs or small tadpoles) and nearly all life history stages disappeared within 12 months. At the fourth site, there was limited reproduction, but it was

The effects of four arthropod diets on the body and organ weights of the leopard frog, Rana pipiens, during vitellogenesis.

Science.gov (United States)

Lehman, G C

1978-12-01

Wild-caught adult Rana pipiens females were captured in midsummer and fed diets of crickets, flies sowbugs or wax moth larvae during a three-month period of active vitellogenesis. The cricket diet supported the most extensive body weight gain during this time and promoted a prolonged period of weight increase in an additional long-term study. Synchronous growth of the oocytes occurred in all four groups, but the ovaries and oviducts of cricket-fed animals were significantly larger than those of frogs on the other three diets. The significantly higher liver weights of frogs fed wax moth larvae may have reflected an augmentation of hepatic energy stores. Fat body weights were also highest in this group of animals. Frogs fed crickets and wax moth larvae possessed larger fat bodies than did the midsummer control animals killed immediately after their arrival in the laboratory. In contrast, frogs fed flies and sowbugs had smaller fat bodies than did the initial controls, suggesting that animals on these diets had utilized fat body lipid during vitellogenesis. Gastrocnemius and final body weights were lowest in frogs fed wax moth larvae. These findings may have reflected the nutritional content of the diet or the reduction in appetite frequently noted in these animals during observations of feeding behavior.

Meal from tilapia filleting industrial waste in the feed of the bullfrog tadpoles (Rana Catesbeiana Shaw, 1802/ Inclusão de farinha de resíduos da indústria de filetagem de tilápias na alimentação de girinos de rã-touro (Rana Catesbeiana Shaw,1802

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Cleiton Manske

2007-08-01

Full Text Available The objective of this experiment was to evaluate the inclusion of meal of tilapia industrial waster in bullfrog tadpoles’ diets (Rana Catesbeina Shaw, 1802. Two hundred fifty tadpoles with initial weight and length of 0,18 ± 0,05g and 2,50 ± 0,18 centimeters were used, respectively, they were used and distributed in 25 aquariums of 30 liter each in a complete randomized design with five treatments and five repetitions. The tadpoles were fed four times a day with diets containing 0, 5, 10 and 15% of inclusion of tilapia filleting and another diet with 0% of supplemented tilapia filleting with synthetic methionine, being supplied four times a day at ease. The experiment period was 30 days. The diets with tilapia filleting inclusion and methionine supplementation did not have influence in the final weight and length averages, feed survival and conversion of bullfrog tadpoles. It cam be used until 15% of tilapia filleting inclusion in the bullfrog tadpoles food. The synthetic methionine supplementation in diets for bullfrog tadpoles is not necessary in diets with levels over 0,47% of the total methionine.Este experimento objetivou avaliar a inclusão da farinha de resíduos de filetagem de tilápias (FT em rações para girinos de rã-touro (Rana Catesbeina Shaw,1802. Foram utilizados 250 girinos com peso e comprimento inicial de 0,18 ± 0,05g e 2,50 ± 0,18 cm, respectivamente, distribuídos em 25 aquários de 30 L cada, em um delineamento inteiramente casualizado com cinco tratamentos e cinco repetições. Os girinos foram alimentados quatro vezes ao dia, com rações contendo 0, 5, 10, 15% de inclusão de FT e outra ração com 0% de FT suplementada com metionina sintética, sendo fornecidas quatro vezes ao dia a vontade. O período do experimento foi de 30 dias. As rações com inclusão de FT e suplementação de metionina não influenciaram nas médias de peso final, comprimento final, sobrevivência e conversão alimentar dos girinos de r

Chemical basis of prey recognition in thamnophiine snakes: the unexpected new roles of parvalbumins.

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Maïté Smargiassi

Full Text Available Detecting and locating prey are key to predatory success within trophic chains. Predators use various signals through specialized visual, olfactory, auditory or tactile sensory systems to pinpoint their prey. Snakes chemically sense their prey through a highly developed auxiliary olfactory sense organ, the vomeronasal organ (VNO. In natricine snakes that are able to feed on land and water, the VNO plays a critical role in predatory behavior by detecting cues, known as vomodors, which are produced by their potential prey. However, the chemical nature of these cues remains unclear. Recently, we demonstrated that specific proteins-parvalbumins-present in the cutaneous mucus of the common frog (Rana temporaria may be natural chemoattractive proteins for these snakes. Here, we show that parvalbumins and parvalbumin-like proteins, which are mainly intracellular, are physiologically present in the epidermal mucous cells and mucus of several frog and fish genera from both fresh and salt water. These proteins are located in many tissues and function as Ca(2+ buffers. In addition, we clarified the intrinsic role of parvalbumins present in the cutaneous mucus of amphibians and fishes. We demonstrate that these Ca(2+-binding proteins participate in innate bacterial defense mechanisms by means of calcium chelation. We show that these parvalbumins are chemoattractive for three different thamnophiine snakes, suggesting that these chemicals play a key role in their prey-recognition mechanism. Therefore, we suggest that recognition of parvalbumin-like proteins or other calcium-binding proteins by the VNO could be a generalized prey-recognition process in snakes. Detecting innate prey defense mechanism compounds may have driven the evolution of this predator-prey interaction.

UNA ESPECIE NUEVA DE RANA DEL GÉNERO CHIASMOCLEIS (MICROHYLIDAE: GASTROPHRYNINAE DE LA CORDILLERA DEL CÓNDOR, ECUADOR

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ANA ALMENDÁRIZ C.

Full Text Available RESUMEN Se describe una especie nueva de rana del género Chiasmocleis de los bosques montanos del suroriente del Ecuador, en las laderas occidentales de la Cordillera del Cóndor, entre 1.025-1.630 m de altitud. En base a nuevas secuencias de ADN mitocondrial y nuclear presentamos las relaciones filogenéticas de la nueva especie y sus congéneres. La filogenia muestra una relación cercana a C. antenori, C. carvalhoi, C. magnova, y C. tridactyla. La nueva especie forma parte de un clado integrado por especies que previamente habían sido asignadas al género Syncope. Este clado es hermano de otro conformado por el resto de especies de Chiasmocleis. La nueva especie difiere de sus congéneres por su dorso café ladrillo a café obscuro (sepia cubierto por puntos diminutos blanco-amarillentos. Chiasmocleis parkeri sp. nov. se parece a Chiasmocleis antenori por la ausencia del dedo I, tanto en las manos como en los pies, pero difiere en la coloración, la disposición y tamaño de las manchas claras y la ausencia de una línea clara en la región cantal. La especie nueva presenta algunos rasgos que le distinguen de especies similares. Describimos el canto, caracterizado por tener notas sin pulsos y aportamos datos ecológicos de la localidad típica y áreas adyacentes.

Influence of larval period on responses of overwintering green frog (Rana clamitans) larvae exposed to contaminated sediments

Energy Technology Data Exchange (ETDEWEB)

Snodgrass, J.W.; Hopkins, W.A.; Jackson, B.P.; Baionno, J.A.; Broughton, J. [Towson State University, Towson, MD (US). Dept. of Biological Science

2005-06-01

Pond-breeding amphibians exhibit large intra- and interspecific differences in the duration of the aquatic larval phase. In contaminated aquatic environments, a prolonged larval phase means prolonged exposure to pollutants and, potentially, more severe toxic effects. In the laboratory, we tested this hypothesis by exposing green frog larvae (Rana clamitans) to commercial clean sand (control), sediment from an abandoned surface mine (mine), or sediment contaminated with coal combustion waste (CCW). By collecting eggs late in the breeding season, we obligated larvae to overwinter and spend a protracted amount of time exposed to contaminated sediments. The experiment was continued until all larvae either successfully completed metamorphosis or died (301 d). Larvae exposed to mine sediments accumulated significant levels of Pb and Zn, whereas larvae exposed to CCW-contaminated sediment accumulated significant levels of As, Se, Sr, and V. Larvae exposed to mine sediments suffered sublethal effects in the form of reduced growth and size at metamorphosis, but the proportion of larvae successfully completing metamorphosis (93%) was the same for both control and mine treatments. In contrast, larvae exposed to CCW-contaminated sediment suffered greatly reduced survival (13%) compared to both control and mine treatments. Moreover, among larvae in the CCW treatment, the majority of mortality occurred during the latter part the overwintering period (after day 205), corresponding to the onset of metamorphosis in the controls. Our results suggest that the length of the larval period may be one of many life-history or ecological characteristics that influence the sensitivity of aquatic breeding amphibians to environmental pollutants.

Journal of Biosciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Biosciences; Volume 28; Issue 6. A skeletochronological study of growth, longevity, and age at sexual maturity in a population of Rana latastei (Amphibia, Anura). Fabio M Guarino Silvia Lunardi Michela Carlomagno Stefano Mazzotti. Articles Volume 28 Issue 6 December 2003 pp 775-782 ...

Predatory leeches (Hirudinida) may contribute to amphibian declines in the Lassen, California.

Science.gov (United States)

Stead Jonathan; Karen Pope

2010-01-01

Researchers have documented precipitous declines in Cascades Frog (Rana cascadae) populations in the southern portion of the species' range, in the Lassen region of California. Reasons for the declines, however, have not been elucidated. In addition to common, widespread causes, an understanding of local community interactions may be necessary...

Primer registro de una población asilvestrada de rana toro (Lithobates catesbeianus en la Provincia de Córdoba, Argentina: Notas sobre la biología de la especie

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Akmentins, Mauricio S.

2008-12-01

Full Text Available En Argentina se ha constatado la presencia de poblaciones asilvestradas de Lithobates catesbeianus en las provincias de San Juan (Sanabria et al., 2005 y de Misiones (Pereyra et al., 2006. Las ranas toro pueden eliminar a los anfibios nativos directamente a través de predación o competencia por interferencia, o indirectamente por competencia por explotación, modificación del comportamiento, alteración del hábitat o introducción de enfermedades o parásitos (Boone et al., 2004. El presente trabajo se realizó en la localidad de Agua de las Piedras (30º48' 46,2"S; 64º12'57,9"O; 760 msnm, la cual se encuentra a 65 km al norte de la ciudad de Córdoba, provincia de Córdoba, Argentina.

Chiricahua leopard frog status in the Galiuro Mountains, Arizona, with a monitoring framework for the species' entire range

Science.gov (United States)

Lawrence L. C. Jones; Michael J. Sredl

2005-01-01

The Chiricahua leopard frog (Rana chiricahuensis) was historically widespread in suitable habitat throughout its range. Reports of recent population declines led to inventories of Chiricahua leopard frog localities. Surveys reported here establish a new baseline of occurrence in the Galiuros: only two of 21 historical localities were found to be...

Ecology of anuran populations inhabiting thermally stressed aquatic ecosystems, with emphasis on larval Rana pipiens and Bufo terrestris

International Nuclear Information System (INIS)

Nelson, D.H.

1974-01-01

Field and laboratory studies were conducted to determine the responses of anuran populations to thermally stressed aquatic ecosystems. Adult and larval amphibians were sampled in and around a cool arm of a 67 ha reservoir that receives high temperature effluent from a nuclear production reactor on the Savannah River Plant (SRP) in South Carolina. Patterns for some species were compared with data from nearby unheated areas and analyzed in terms of the thermal gradient (16-45 C) extending the length of the reservoir's cool arm. The adaptation to breeding during nocturnal rainfall fortuitously confers a double advantage especially to anurans breeding in thermally stressed waters. (U.S.)

NUEVA ESPECIE DE RANA BROMELÍCOLA DEL GÉNERO PRISTIMANTIS (AMPHIBIA: CRAUGASTORIDAE, MESETA DE LA CORDILLERA DEL CÓNDOR, ECUADOR

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JORGE BRITO M.

Full Text Available RESUMEN Describimos una especie pequeña de rana bromelícola del género Pristimantis (longitud rostro-cloaca en hembras 20.3-23.3 mm; en machos 16.1-17.4 mm, proveniente de una remota meseta de arenisca de la Cordillera del Cóndor, en el sureste de Ecuador, con un rango altitudinal de 2.045-2.860 m. Una filogenia en base a secuencias de ADN (genes mitocondriales y nucleares muestra que la nueva especie forma parte del grupo P. orestes y está más cercanamente relacionada con una especie de Pristimantis aún no descrita de la vertiente sur oriental ecuatoriana. Difiere de sus congéneres de Ecuador, por su coloración dorsal y ventral predominantemente negra; superficie palmar amplia y robusta con dedos cortos y gruesos; presencia de un surco profundo y amplio extendido desde la base anterior del I dedo manual hasta la base posterior del tubérculo palmar; tubérculos subarticulares divididos, tubérculos supernumerarios agrandados y con granulaciones pequeñas. Todos los individuos registrados estuvieron en bromelias terrestres. Las llamadas son cortas, de frecuencia modulada, conformada por una nota con duración de 5-15 ms. Los insectos representaron el 80% de la dieta de la especie nueva.

Interactions between freshwater snails and tadpoles: competition and facilitation.

Science.gov (United States)

Brönmark, Christer; Rundle, Simon D; Erlandsson, Ann

1991-06-01

Freshwater snails and anuran tadpoles have been suggested to have their highest population densities in ponds of intermediate size where abiotic disturbance (e.g. desiccation) is low and large predators absent. Both snails and tadpoles feed on periphytic algae and, thus, there should be a large potential for competitive interactions to occur between these two distantly related taxa. In a field experiment we examined the relative strength of competition between two closely related snail species, Lymnaea stagnalis and L. peregra, and between L. stagnalis and tadpoles of the common frog, Rana temporaria. Snail growth and egg production and tadpole size at and time to metamorphosis were determined. Effects on the common food source, periphyton, were monitored with the aid of artificial substrates. Periphyton dry weight was dramatically reduced in the presence of snails and/or tadpoles. There were no competitive effects on growth or egg production of the two snail species when they were coexisting. Mortality of L. peregra was high (95%) after reproduction, but independent of treatment. Growth of L. stagnalis was reduced only at the highest tadpole densities, whereas egg production was reduced both by intraspecific competition and by competition with tadpoles. Differences in egg production were retained after tadpole metamorphosis. Tadpole larval period increased, weight of metamorphosing frogs decreased and growth rate was reduced as a function of increasing tadpole density. However, contrary to expectation, snails had a positive effect on tadpole larval period, weight and growth rate. Further, in experimental containers without snails there was a dense growth of the filamentous green alga Cladophora sp. We suggest that the facilitative effects of snails on tadpoles are due to an "indirect mutualistic" mechanism, involving competition between food sources of different quality (microalgae and Cladophora sp.) and tadpoles being competitively dominant over snails for the

Assessment of heavy metals and metalloids in tissues of two frog species: Rana tigrina and Euphlyctis cyanophlyctis from industrial city Sialkot, Pakistan.

Science.gov (United States)

Qureshi, Irfan Zia; Kashif, Zeshan; Hashmi, Muhammad Zaffar; Su, Xiaomei; Malik, Riffat Naseem; Ullah, Kalim; Hu, Jinxing; Dawood, Muhammad

2015-09-01

In the present study, we investigated the concentrations of Ni, Fe, Pb, Cu, Co, Zn, Cd, Mn, and Cr in selected body tissues (liver, stomach, kidney, heart, lungs, and skeletal muscles) of two frog species: Rana tigrina and Euphlyctis cyanophlyctis captured from industrial wastewater of Sialkot city known worldwide for its tanning industry. The both frog species had darker appearance, distinctively different wet body weight, and snout-vent length. The results revealed that the heavy metal concentrations were high in the samples collected from industrial sites as compared to non-industrial sites. The different tissues of R. tigrina and E. cyanophlyctis exhibited little significant differences from two sites. The concentrations of heavy metals were more in tissues of R. tigrina as compared to E. cyanophlyctis. Mean concentration of Cd, Fe, Ni, Mn, Cu, and Cr was comparatively greater in R. tigrina, whereas Pb and Co were higher in E. cyanophlyctis. The concentration of Cu and Cd in the liver and kidney were relatively more in both species as compared to other organs. Further, the results indicated that frogs collected from industrial sites showed decreased body length and weight, and greater metal accumulation. The results will help the authorities for the conservation of these frog species which are under the influence of heavy metal contamination.

Effects of maturation and acidosis on the chaos-like complexity of the neural respiratory output in the isolated brainstem of the tadpole, Rana esculenta.

Science.gov (United States)

Straus, Christian; Samara, Ziyad; Fiamma, Marie-Noëlle; Bautin, Nathalie; Ranohavimparany, Anja; Le Coz, Patrick; Golmard, Jean-Louis; Darré, Pierre; Zelter, Marc; Poon, Chi-Sang; Similowski, Thomas

2011-05-01

Human ventilation at rest exhibits mathematical chaos-like complexity that can be described as long-term unpredictability mediated (in whole or in part) by some low-dimensional nonlinear deterministic process. Although various physiological and pathological situations can affect respiratory complexity, the underlying mechanisms remain incompletely elucidated. If such chaos-like complexity is an intrinsic property of central respiratory generators, it should appear or increase when these structures mature or are stimulated. To test this hypothesis, we employed the isolated tadpole brainstem model [Rana (Pelophylax) esculenta] and recorded the neural respiratory output (buccal and lung rhythms) of pre- (n = 8) and postmetamorphic tadpoles (n = 8), at physiologic (7.8) and acidic pH (7.4). We analyzed the root mean square of the cranial nerve V or VII neurograms. Development and acidosis had no effect on buccal period. Lung frequency increased with development (P acidosis, but in postmetamorphic tadpoles only (P respiratory central rhythm generator accounts for ventilatory chaos-like complexity, especially in the postmetamorphic stage and at low pH. According to the ventilatory generators homology theory, this may also be the case in mammals.

Effects of maturation and acidosis on the chaos-like complexity of the neural respiratory output in the isolated brainstem of the tadpole, Rana esculenta

Science.gov (United States)

Samara, Ziyad; Fiamma, Marie-Noëlle; Bautin, Nathalie; Ranohavimparany, Anja; Le Coz, Patrick; Golmard, Jean-Louis; Darré, Pierre; Zelter, Marc; Poon, Chi-Sang; Similowski, Thomas

2011-01-01

Human ventilation at rest exhibits mathematical chaos-like complexity that can be described as long-term unpredictability mediated (in whole or in part) by some low-dimensional nonlinear deterministic process. Although various physiological and pathological situations can affect respiratory complexity, the underlying mechanisms remain incompletely elucidated. If such chaos-like complexity is an intrinsic property of central respiratory generators, it should appear or increase when these structures mature or are stimulated. To test this hypothesis, we employed the isolated tadpole brainstem model [Rana (Pelophylax) esculenta] and recorded the neural respiratory output (buccal and lung rhythms) of pre- (n = 8) and postmetamorphic tadpoles (n = 8), at physiologic (7.8) and acidic pH (7.4). We analyzed the root mean square of the cranial nerve V or VII neurograms. Development and acidosis had no effect on buccal period. Lung frequency increased with development (P Chaos-like complexity, assessed through the noise limit, increased from pH 7.8 to pH 7.4 (P chaos-like complexity, especially in the postmetamorphic stage and at low pH. According to the ventilatory generators homology theory, this may also be the case in mammals. PMID:21325645

Selection, trans-species polymorphism, and locus identification of major histocompatibility complex class IIβ alleles of New World ranid frogs

Science.gov (United States)

Kiemnec-Tyburczy, Karen M.; Richmond, Jonathan Q.; Savage, Anna E.; Zamudio, Kelly R.

2010-01-01

Genes encoded by the major histocompatibility complex (MHC) play key roles in the vertebrate immune system. However, our understanding of the evolutionary processes and underlying genetic mechanisms shaping these genes is limited in many taxa, including amphibians, a group currently impacted by emerging infectious diseases. To further elucidate the evolution of the MHC in frogs (anurans) and develop tools for population genetics, we surveyed allelic diversity of the MHC class II ??1 domain in both genomic and complementary DNA of seven New World species in the genus Rana (Lithobates). To assign locus affiliation to our alleles, we used a "gene walking" technique to obtain intron 2 sequences that flanked MHC class II?? exon 2. Two distinct intron sequences were recovered, suggesting the presence of at least two class II?? loci in Rana. We designed a primer pair that successfully amplified an orthologous locus from all seven Rana species. In total, we recovered 13 alleles and documented trans-species polymorphism for four of the alleles. We also found quantitative evidence of selection acting on amino acid residues that are putatively involved in peptide binding and structural stability of the ??1 domain of anurans. Our results indicated that primer mismatch can result in polymerase chain reaction (PCR) bias, which influences the number of alleles that are recovered. Using a single locus may minimize PCR bias caused by primer mismatch, and the gene walking technique was an effective approach for generating single-copy orthologous markers necessary for future studies of MHC allelic variation in natural amphibian populations. ?? 2010 Springer-Verlag.

NCBI nr-aa BLAST: CBRC-PMAR-01-0317 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-PMAR-01-0317 gb|AAL06717.1| type III GnRH receptor splice variant 2 [Rana catesbeia...na] gb|AAL06718.1| type III GnRH receptor splice variant 3 [Rana catesbeiana] gb|AAL06719.1| type III GnRH receptor splice variant 4 [Rana catesbeiana] AAL06717.1 3e-67 63% ...

NCBI nr-aa BLAST: CBRC-EEUR-01-0693 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-EEUR-01-0693 gb|AAL06717.1| type III GnRH receptor splice variant 2 [Rana catesbeia...na] gb|AAL06718.1| type III GnRH receptor splice variant 3 [Rana catesbeiana] gb|AAL06719.1| type III GnRH receptor splice variant 4 [Rana catesbeiana] AAL06717.1 2e-41 58% ...

NCBI nr-aa BLAST: CBRC-VPAC-01-1004 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-VPAC-01-1004 gb|AAL06717.1| type III GnRH receptor splice variant 2 [Rana catesbeia...na] gb|AAL06718.1| type III GnRH receptor splice variant 3 [Rana catesbeiana] gb|AAL06719.1| type III GnRH receptor splice variant 4 [Rana catesbeiana] AAL06717.1 4e-38 57% ...

Evaluation of the effects of titanium dioxide nanoparticles on cultured Rana catesbeiana tailfin tissue

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S. Austin eHammond

2013-11-01

Full Text Available Nanoparticles (NPs, materials that have one dimension less than 100 nm, are used in manufacturing, health and food products, and consumer products including cosmetics, clothing and household appliances. Their utility to industry is derived from their high surface-area-to-volume ratios and physico-chemical properties distinct from their bulk counterparts, but the near-certainty that NPs will be released into the environment raises the possibility that they could present health risks to humans and wildlife. The thyroid hormones (THs, thyroxine and 3,3’,5-triiodothyronine (T3, are involved in development and metabolism in vertebrates including humans and frogs. Many of the processes of anuran metamorphosis are analogous to human post-embryonic development and disruption of TH action can have drastic effects. These shared features make the metamorphosis of anurans an excellent model for screening for endocrine disrupting chemicals (EDCs. We used the cultured tailfin (C-fin assay to examine the exposure effects of 0.1-10 nM (~8-800 ng/L of three types of ~20 nm TiO2 NPs (P25, M212, M262 and micron-sized TiO2 (μTiO2 ±10 nM T3. The actual Ti levels were 40.9 – 64.7% of the nominal value. Real-time quantitative polymerase chain reaction (QPCR was used to measure the relative amounts of mRNA transcripts encoding TH-responsive thyroid hormone receptors (thra and thrb and Rana larval keratin type I (rlk1, as well as the cellular stress-responsive heat shock protein 30 kDa (hsp30, superoxide dismutase (sod, and catalase (cat. The levels of the TH-responsive transcripts were largely unaffected by any form of TiO2. Some significant effects on stress-related transcripts were observed upon exposure to micron-sized TiO2, P25 and M212 while no effect was observed with M262 exposure. Therefore the risk of adversely affecting amphibian tissue by disrupting TH-signalling or inducing cellular stress is low for these compounds relative to other previously

Hind limb malformations in free-living northern leopard frogs (Rana pipiens) from Maine, Minnesota, and Vermont suggest multiple etiologies

Science.gov (United States)

Meteyer, C.U.; Loeffler, I.K.; Fallon, J.F.; Converse, K.A.; Green, E.; Helgen, J.C.; Kersten, S.; Levey, R.; Eaton-Poole, L.; Burkhart, J.G.

2000-01-01

Background Reports of malformed frogs have increased throughout the North American continent in recent years. Most of the observed malformations have involved the hind limbs. The goal of this study was to accurately characterize the hind limb malformations in wild frogs as an important step toward understanding the possible etiologies. Methods During 1997 and 1998, 182 recently metamorphosed northern leopard frogs (Rana pipiens) were collected from Minnesota, Vermont, and Maine. Malformed hind limbs were present in 157 (86%) of these frogs, which underwent necropsy and radiographic evaluation at the National Wildlife Health Center. These malformations are described in detail and classified into four major categories: (1) no limb (amelia); (2) multiple limbs or limb elements (polymelia, polydactyly, polyphalangy); (3) reduced limb segments or elements (phocomelia, ectromelia, ectrodactyly, and brachydactyly; and (4) distally complete but malformed limb (bone rotations, bridging, skin webbing, and micromelia). Results Amelia and reduced segments and/or elements were the most common finding. Frogs with bilateral hind limb malformations were not common, and in only eight of these 22 frogs were the malformations symmetrical. Malformations of a given type tended to occur in frogs collected from the same site, but the types of malformations varied widely among all three states, and between study sites within Minnesota. Conclusions Clustering of malformation type suggests that developmental events may produce a variety of phenotypes depending on the timing, sequence, and severity of the environmental insult. Hind limb malformations in free-living frogs transcend current mechanistic explanations of tetrapod limb development.

Histopathological changes and erythrocytic nuclear abnormalities in Iberian green frogs (Rana perezi Seoane) from a uranium mine pond

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Marques, S.M. [Departamento de Biologia/Centro de Estudos do Ambiente e do Mar (CESAM), Campus de Santiago, Universidade de Aveiro, 3810-193 Aveiro (Portugal)], E-mail: s.reis.marques@gmail.com; Antunes, S.C. [Departamento de Biologia/Centro de Estudos do Ambiente e do Mar (CESAM), Campus de Santiago, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Pissarra, H. [Laboratorio de Anatomia Patologica, Centro de Investigacao Interdisciplinar em Sanidade Animal (CIISA), Faculdade de Medicina Veterinaria, U.T.L., Lisboa (Portugal); Pereira, M.L. [Departamento de Biologia/Centro de Investigacao em Materiais Ceramicos e Compositos (CICECO), Campus de Santiago, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Goncalves, F.; Pereira, R. [Departamento de Biologia/Centro de Estudos do Ambiente e do Mar (CESAM), Campus de Santiago, Universidade de Aveiro, 3810-193 Aveiro (Portugal)

2009-01-31

In spite of their sensitivity to anthropogenic stressors, adults of Rana perezi Seoane were found inhabiting effluent ponds from a uranium mine. Due to the presence of such organisms in this environment, it becomes of paramount importance to assess the damages induced by local contamination on these aquatic vertebrates, in order to integrate this information on a site-specific risk assessment that is being carried out in the area. To attain this purpose an ethically and statistically acceptable number of green frogs were captured in the mine pond (M) and in a pristine river (VR), a few kilometres from the mine. Bioaccumulation of metals and histopathological alterations were evaluated in the liver, kidneys, spleen, lungs and testes of the animals. Simultaneously, blood samples were collected for the evaluation of genotoxic damage on erythrocytes. Animals captured in the M pond showed significantly increased levels of Be, Al, Mn, Fe and U in the liver, as well as Pb and U in the kidney. The liver was the main target organ for the bioaccumulation of Be, Al, Fe and U. However, renal histopathologies were more severe than those of liver. The main tissue alterations recorded in animals from the mine were: a slight increase in melanomacrophagic centers (MMC) in liver, lung and kidneys; dilatation of the renal tubules lumen associated with tubular necrosis. A significantly higher number of erythrocytic abnormalities (lobed, notched and kidney shaped nuclei and micronuclei) were recorded in frogs from M than in frogs from VR, along with a significantly lower frequency of immature erythrocytes. Both observations suggested that the removal of abnormal blood cells might be compromised.

Histopathological changes and erythrocytic nuclear abnormalities in Iberian green frogs (Rana perezi Seoane) from a uranium mine pond

International Nuclear Information System (INIS)

Marques, S.M.; Antunes, S.C.; Pissarra, H.; Pereira, M.L.; Goncalves, F.; Pereira, R.

2009-01-01

In spite of their sensitivity to anthropogenic stressors, adults of Rana perezi Seoane were found inhabiting effluent ponds from a uranium mine. Due to the presence of such organisms in this environment, it becomes of paramount importance to assess the damages induced by local contamination on these aquatic vertebrates, in order to integrate this information on a site-specific risk assessment that is being carried out in the area. To attain this purpose an ethically and statistically acceptable number of green frogs were captured in the mine pond (M) and in a pristine river (VR), a few kilometres from the mine. Bioaccumulation of metals and histopathological alterations were evaluated in the liver, kidneys, spleen, lungs and testes of the animals. Simultaneously, blood samples were collected for the evaluation of genotoxic damage on erythrocytes. Animals captured in the M pond showed significantly increased levels of Be, Al, Mn, Fe and U in the liver, as well as Pb and U in the kidney. The liver was the main target organ for the bioaccumulation of Be, Al, Fe and U. However, renal histopathologies were more severe than those of liver. The main tissue alterations recorded in animals from the mine were: a slight increase in melanomacrophagic centers (MMC) in liver, lung and kidneys; dilatation of the renal tubules lumen associated with tubular necrosis. A significantly higher number of erythrocytic abnormalities (lobed, notched and kidney shaped nuclei and micronuclei) were recorded in frogs from M than in frogs from VR, along with a significantly lower frequency of immature erythrocytes. Both observations suggested that the removal of abnormal blood cells might be compromised

Cool tadpoles from Arctic environments waste fewer nutrients - high gross growth efficiencies lead to low consumer-mediated nutrient recycling in the North.

Science.gov (United States)

Liess, Antonia; Guo, Junwen; Lind, Martin I; Rowe, Owen

2015-11-01

Endothermic organisms can adapt to short growing seasons, low temperatures and nutrient limitation by developing high growth rates and high gross growth efficiencies (GGEs). Animals with high GGEs are better at assimilating limiting nutrients and thus should recycle (or lose) fewer nutrients. Longer guts in relation to body mass may facilitate higher GGE under resource limitation. Within the context of ecological stoichiometry theory, this study combines ecology with evolution by relating latitudinal life-history adaptations in GGE, mediated by gut length, to its ecosystem consequences, such as consumer-mediated nutrient recycling. In common garden experiments, we raised Rana temporaria tadpoles from two regions (Arctic/Boreal) under two temperature regimes (18/23 °C) crossed with two food quality treatments (high/low-nitrogen content). We measured tadpole GGEs, total nutrient loss (excretion + egestion) rates and gut length during ontogeny. In order to maintain their elemental balance, tadpoles fed low-nitrogen (N) food had lower N excretion rates and higher total phosphorous (P) loss rates than tadpoles fed high-quality food. In accordance with expectations, Arctic tadpoles had higher GGEs and lower N loss rates than their low-latitude conspecifics, especially when fed low-N food, but only in ambient temperature treatments. Arctic tadpoles also had relatively longer guts than Boreal tadpoles during early development. That temperature and food quality interacted with tadpole region of origin in affecting tadpole GGEs, nutrient loss rates and relative gut length, suggests evolved adaptation to temperature and resource differences. With future climate change, mean annual temperatures will increase. Additionally, species and genotypes will migrate north. This will change the functioning of Boreal and Arctic ecosystems by affecting consumer-mediated nutrient recycling and thus affect nutrient dynamics in general. Our study shows that evolved latitudinal adaption can

Cumulative effects of road de-icing salt on amphibian behavior.

Science.gov (United States)

Denoël, Mathieu; Bichot, Marion; Ficetola, Gentile Francesco; Delcourt, Johann; Ylieff, Marc; Kestemont, Patrick; Poncin, Pascal

2010-08-15

Despite growing evidence of the detrimental effect of chemical substances on organisms, limited research has focused on changes in behavioral patterns, in part due to the difficulties to obtain detailed quantitative data. Recent developments in efficient computer-based video analyses have allowed testing pesticide effects on model species such as the zebrafish. However, these new techniques have not yet been applied to amphibians and directly to conservation issues, i.e., to assess toxicological risks on threatened species. We used video-tracking analyses to test a quantitative effect of an environmental contaminant on the locomotion of amphibian tadpoles (Rana temporaria) by taking into account cumulative effects. Because recent research has demonstrated effects of de-icing salts on survival and community structure, we used sodium chloride in our experimental design (25 replicates, 4 concentrations, 4 times) to test for an effect at the scale of behavior at environmentally relevant concentrations. Analysis of 372 1-h video-tracks (5 samples/s) showed a complex action of salts on behavioral patterns with a dose and cumulative response over time. Although no effects were found on mortality or growth, the highest salt concentrations reduced the speed and movement of tadpoles in comparison with control treatments. The reduced locomotor performance could have detrimental consequences in terms of tadpoles' responses to competition and predation and may be an indicator of the low concentration effect of the contaminant. On one hand, this study demonstrates the usefulness of examining behavior to address conservation issues and understand the complex action of environmental factors and, more particularly, pollutants on organisms. On the other hand, our results highlight the need of new computerized techniques to quantitatively analyze these patterns. (c) 2010 Elsevier B.V. All rights reserved.

Influência da baixa temperatura ambiental sobre a inflamação em rã-touro gigante (Rana catesbeiana: avaliações qualitativa e quantitativa

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José Luiz Catão-Dias

1999-01-01

Full Text Available O presente trabalho teve por objetivo investigar a modulação exercida pela temperatura ambiental sobre a cinética celular inflamatória experimentalmente induzida em Rana catesbeiana, rã-touro gigante. Para tanto, 120 espécimes pós-metamórficos foram mantidos a 6ºC e 24ºC e tratados pela transfixação do tecido muscular da coxa por fio de sutura ou injeção intramuscular de carragenina. Os resultados obtidos através de avaliações qualitativa e quantitativa do foco lesional mostraram que a baixa temperatura ambiental modula significativamente a evolução do processo inflamatório. Animais mantidos a 6ºC, em ambos os modelos, apresentaram números de células inflamatórias significativamente menores que os verificados a 24ºC, independentemente do tempo de avaliação. Por outro lado, algum fator pertencente aos mecanismos de defesa do hospedeiro não deve ter sido bloqueado pela temperatura, visto que a área de reação à injúria mostrou-se equivalente na maioria dos tempos pesquisados.

Octylphenol and UV-B radiation alter larval development and hypothalamic gene expression in the leopard frog (Rana pipiens).

Science.gov (United States)

Crump, Douglas; Lean, David; Trudeau, Vance L

2002-03-01

We assessed octylphenol (OP), an estrogenic endocrine-disrupting chemical, and UV-B radiation, a known stressor in amphibian development, for their effects on hypothalamic gene expression and premetamorphic development in the leopard frog Rana pipiens. Newly hatched tadpoles were exposed for 10 days to OP alone at two different dose levels; to subambient UV-B radiation alone; and to two combinations of OP and UV-B. Control animals were exposed to ethanol vehicle (0.01%) exposure, a subset of tadpoles from each treatment group was raised to metamorphosis to assess differences in body weight and time required for hindlimb emergence. Tadpoles from one of the OP/UV-B combination groups had greater body weight and earlier hindlimb emergence (p weight or hindlimb emergence, indicating a potential mechanism of interaction between OP and UV-B. We hypothesized that the developing hypothalamus might be a potential environmental sensor for neurotoxicologic studies because of its role in the endocrine control of metamorphosis. We used a differential display strategy to identify candidate genes differentially expressed in the hypothalamic region of the exposed tadpoles. Homology cloning was performed to obtain R. pipiens glutamate decarboxylases--GAD65 and GAD67, enzymes involved in the synthesis of the neurotransmitter gamma-aminobutyric acid (GABA). cDNA expression profiles revealed that OP and UV-B affected the levels of several candidate transcripts in tadpole (i.e., Nck, Ash, and phospholipase C gamma-binding protein 4 and brain angiogenesis inhibitor-3) and metamorph (i.e., GAD67, cytochrome C oxidase, and brain angiogenesis inhibitor-2 and -3) brains. This study represents a novel approach in toxicology that combines physiologic and molecular end points and indicates that levels of OP commonly found in the environment and subambient levels of UV-B alter the expression of important hypothalamic genes and disrupt tadpole growth patterns.

Amphibians of the Simbruini Mountains (Latium, Central Italy

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Pierangelo Crucitti

2010-07-01

Full Text Available Little attention has been paid to the herpetological fauna of the Simbruini Mountains Regional Park, Latium (Central Italy. In this study, we surveyed 50 sites in the course of about ten years of field research, especially during the period 2005-2008. Nine amphibian species, four Caudata and five Anura, 60.0% out of the 15 amphibian species so far observed in Latium, were discovered in the protected area: Salamandra salamandra, Salamandrina perspicillata, Lissotriton vulgaris, Triturus carnifex, Bombina pachypus, Bufo balearicus, Bufo bufo, Rana dalmatina, Rana italica. Physiography of sites has been detailed together with potential threatening patterns. For each species the following topics have been discussed; ecology of sites, altitudinal distribution, phenology, sintopy. Salamandra salamandra and Bombina pachypus are at higher risk. The importance of the maintenance of artificial/natural water bodies for the conservation management of amphibian population of this territory is discussed.

The role of MEF2 transcription factors in dehydration and anoxia survival in Rana sylvatica skeletal muscle

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Myriam P. Hoyeck

2017-11-01

Full Text Available The wood frog (Rana sylvatica can endure freezing of up to 65% of total body water during winter. When frozen, wood frogs enter a dormant state characterized by a cessation of vital functions (i.e., no heartbeat, blood circulation, breathing, brain activity, or movement. Wood frogs utilize various behavioural and biochemical adaptations to survive extreme freezing and component anoxia and dehydration stresses, including a global suppression of metabolic functions and gene expression. The stress-responsive myocyte enhancer factor-2 (MEF2 transcription factor family regulates the selective expression of genes involved in glucose transport, protein quality control, and phosphagen homeostasis. This study examined the role of MEF2A and MEF2C proteins as well as select downstream targets (glucose transporter-4, calreticulin, and muscle and brain creatine kinase isozymes in 40% dehydration and 24 h anoxia exposure at the transcriptional, translational, and post-translational levels using qRT-PCR, immunoblotting, and subcellular localization. Mef2a/c transcript levels remained constant during dehydration and anoxia. Total, cytoplasmic, and nuclear MEF2A/C and phospho-MEF2A/C protein levels remained constant during dehydration, whereas a decrease in total MEF2C levels was observed during rehydration. Total and phospho-MEF2A levels remained constant during anoxia, whereas total MEF2C levels decreased during 24 h anoxia and P-MEF2C levels increased during 4 h anoxia. In contrast, cytoplasmic MEF2A levels and nuclear phospho-MEF2A/C levels were upregulated during anoxia. MEF2 downstream targets remained constant during dehydration and anoxia, with the exception of glut4 which was upregulated during anoxia. These results suggest that the upregulated MEF2 response reported in wood frogs during freezing may in part stem from their cellular responses to surviving prolonged anoxia, rather than dehydration, leading to an increase in GLUT4 expression which may

Persistence of a circadian rhythmicity for thyroid hormones in plasma and thyroid of hibernating male Rana ridibunda.

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Kühn, E R; Delmotte, N M; Darras, V M

1983-06-01

The presence and circadian rhythmicity of thyroid hormones was studied in plasma and the thyroid gland of male Rana ridibunda before and during hibernation. Hibernating January frogs do have a lower T3 and T4 content of their thyroid gland whereas plasma levels of T3 are maintained and of T4 increased compared to fed September or October frogs. It seems likely that the increased photoperiod in January will be responsible for this increased T4 secretion, since controlled laboratory experiments performed in December did not reveal any influence of low temperature on circulating T3 or T4 levels. Also feeding does not influence circulating levels and thyroid content of thyroid hormones in frogs kept at room temperature during the month of January. A circadian rhythmicity of T3 and T4 in the thyroid gland is present in fed October frogs and in non fed December frogs acclimated at 5 degrees C for 12 days with an acrophase for T3 at approximately 1500 h and for T4 at around 1900 h, whereas in plasma only T3 does have circadian variations (acrophase about midnight) but not T4. When December frogs are acclimated to room temperature for 12 days, frogs are active again, but do not eat and have a lower body weight than frogs hibernating at 5 degrees C. Their T3 content of the thyroid gland has disappeared, but T4 thyroid content and plasma levels of T3 and T4 are maintained. As in hibernating frogs, no circadian variations in T4 plasma concentrations are present whereas the circadian thyroid T4 rhythm disappears. At the same time a dampening in rhythmicity for plasma T3 as judged by the significantly lower amplitude occurs. It is concluded that the persistence of circulating levels of thyroid hormones and of a circadian cyclicity for T3 in plasma in non feeding hibernating frogs may reflect the special metabolic state e.g. availability of food reserves in these animals.

VRIJEDNOST KARBOKSITERAPIJE PRI LIJEČENJU KRONIČNE RANE POTKOLJENICE

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KOVAČEVIĆ, JADRANKA; SINOŽIĆ, TAMARA

2015-01-01

Karboksiterapija je potporna metoda liječenja kroničnih rana koja se provodi kutanim ili subkutanim ubrizgavanjem medicinskog ugljičnog dioksida (Co2). osnovni princip djelovanja ubrizganog plina Co2 je korekcija tkivne hipoksije temeljem Bohrovog efekta. Djelujući na endotelne faktore rasta potiče neoangiogenezu te stimuliraju ibroblaste na sintezu kolagena što sve zajedno dovodi do boljeg zacjeljivanja rana. Brojna su područja primjene karboksiterapije: od liječenja kroničnih rana, bolesti ...

Metals in riparian wildlife of the lead mining district of southeastern Missouri. [Rana catesbeiana, Ondatra zibethicus; Butorides striatus; Nerodia sipedon; Stelgidopteryx serripennis, Riparia riparia

Energy Technology Data Exchange (ETDEWEB)

Niethammer, K.R.; Atkinson, R.D.; Baskett, T.S.; Samson, F.B.

1985-03-01

Five species of riparian vertebrates (425 individuals) primarily representing upper trophic levels were collected from the Big River and Black River drainages in two lead mining districts of southeastern Missouri, 1981-82. Big River is subject to metal pollution via erosion and seepage from large tailings piles from inactive lead mines. Black River drains part of a currently mined area. Bull-frogs (Rana catesbeiana), muskrats (Ondatra zibethicus), and green-backed herons (Butorides striatus) collected downstream from the source of metal contamination to Big River had significantly higher lead and cadmium levels than specimens collected at either an uncontaminated upstream site or on Black River. Northern water snakes (Nerodia sipedon) had elevated lead levels below the tailings source, but did not seem to accumulate cadmium. Levels of lead, cadmium, or zinc in northern rough-winged swallows (Stelgidopteryx serripennis) were not related to collecting locality. Carcasses of ten bank swallows (Riparia riparia) collected from a colony nesting in a tailings pile along the Big River had lead concentrations of 2.0-39 ppm wet weight. Differences between zinc concentrations in vertebrates collected from contaminated and uncontaminated sites were less apparent than differences in lead and cadmium. There was little relationship between metal concentrations in the animals studied and their trophic levels. Bull-frogs are the most promising species examined for monitoring environmental levels of lead, cadmium, and zinc.

De novo Transcriptome Assemblies of Rana (Lithobates catesbeiana and Xenopus laevis Tadpole Livers for Comparative Genomics without Reference Genomes.

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Inanc Birol

Full Text Available In this work we studied the liver transcriptomes of two frog species, the American bullfrog (Rana (Lithobates catesbeiana and the African clawed frog (Xenopus laevis. We used high throughput RNA sequencing (RNA-seq data to assemble and annotate these transcriptomes, and compared how their baseline expression profiles change when tadpoles of the two species are exposed to thyroid hormone. We generated more than 1.5 billion RNA-seq reads in total for the two species under two conditions as treatment/control pairs. We de novo assembled these reads using Trans-ABySS to reconstruct reference transcriptomes, obtaining over 350,000 and 130,000 putative transcripts for R. catesbeiana and X. laevis, respectively. Using available genomics resources for X. laevis, we annotated over 97% of our X. laevis transcriptome contigs, demonstrating the utility and efficacy of our methodology. Leveraging this validated analysis pipeline, we also annotated the assembled R. catesbeiana transcriptome. We used the expression profiles of the annotated genes of the two species to examine the similarities and differences between the tadpole liver transcriptomes. We also compared the gene ontology terms of expressed genes to measure how the animals react to a challenge by thyroid hormone. Our study reports three main conclusions. First, de novo assembly of RNA-seq data is a powerful method for annotating and establishing transcriptomes of non-model organisms. Second, the liver transcriptomes of the two frog species, R. catesbeiana and X. laevis, show many common features, and the distribution of their gene ontology profiles are statistically indistinguishable. Third, although they broadly respond the same way to the presence of thyroid hormone in their environment, their receptor/signal transduction pathways display marked differences.

A review on fungal diseases of algae, marine fishes, shrimps and corals

Digital Repository Service at National Institute of Oceanography (India)

Ramaiah, N.

parasite of Rana esculenta in Central Italy. These authors have listed species designated to this genus (and authorities, references can be found in Palusconi et al 18 ):Dermocystidium pusula Pérez, 1907; Dermocystidium ranae Guyenot & Naville, 1922...

Identification of individual foothill yellow-legged frogs (Rana boylii) using chin pattern photographs: a non-invasive and effective method for small population studies

Science.gov (United States)

K.R. Marlow; K.D. Wiseman; Clara Wheeler; J.E.  Drennan; R.E.  Jackman

2016-01-01

The ability to identify individual animals is a valuable tool in the study of amphibian population dynamics, movement ecology, social behavior, and habitat use. Numerous methods of marking amphibians have been employed including the use of passive integrated transponder (PIT) tags, radio-transmitters, elastomers, branding, and mutilation techniques such as toe...

Regulation of 5'-adenosine monophosphate deaminase in the freeze tolerant wood frog, Rana sylvatica.

Science.gov (United States)

Dieni, Christopher A; Storey, Kenneth B

2008-04-22

The wood frog, Rana sylvatica, is one of a few vertebrate species that have developed natural freeze tolerance, surviving days or weeks with 65-70% of its total body water frozen in extracellular ice masses. Frozen frogs exhibit no vital signs and their organs must endure multiple stresses, particularly long term anoxia and ischemia. Maintenance of cellular energy supply is critical to viability in the frozen state and in skeletal muscle, AMP deaminase (AMPD) plays a key role in stabilizing cellular energetics. The present study investigated AMPD control in wood frog muscle. Wood frog AMPD was subject to multiple regulatory controls: binding to subcellular structures, protein phosphorylation, and effects of allosteric effectors, cryoprotectants and temperature. The percentage of bound AMPD activity increased from 20 to 35% with the transition to the frozen state. Bound AMPD showed altered kinetic parameters compared with the free enzyme (S0.5 AMP was reduced, Hill coefficient fell to approximately 1.0) and the transition to the frozen state led to a 3-fold increase in S0.5 AMP of the bound enzyme. AMPD was a target of protein phosphorylation. Bound AMPD from control frogs proved to be a low phosphate form with a low S0.5 AMP and was phosphorylated in incubations that stimulated PKA, PKC, CaMK, or AMPK. Bound AMPD from frozen frogs was a high phosphate form with a high S0.5 AMP that was reduced under incubation conditions that stimulated protein phosphatases. Frog muscle AMPD was activated by Mg.ATP and Mg.ADP and inhibited by Mg.GTP, KCl, NaCl and NH4Cl. The enzyme product, IMP, uniquely inhibited only the bound (phosphorylated) enzyme from muscle of frozen frogs. Activators and inhibitors differentially affected the free versus bound enzyme. S0.5 AMP of bound AMPD was also differentially affected by high versus low assay temperature (25 vs 5 degrees C) and by the presence/absence of the natural cryoprotectant (250 mM glucose) that accumulates during freezing

Journal of Biosciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

Author Affiliations. Anjali Verma1 Nikhil Kumar2 S A Ranade1. Plant Molecular Biology, National Botanical Research Institute, Rana Pratap Marg, Lucknow 226 001, India; Betelvine Laboratories, National Botanical Research Institute, Rana Pratap Marg, Lucknow 226 001, India ...

Estrogenic exposure affects metamorphosis and alters sex ratios in the northern leopard frog (Rana pipiens): identifying critically vulnerable periods of development.

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Hogan, Natacha S; Duarte, Paula; Wade, Michael G; Lean, David R S; Trudeau, Vance L

2008-05-01

During the transformation from larval tadpole to juvenile frog, there are critical periods of metamorphic development and sex differentiation that may be particularly sensitive to endocrine disruption. The aim of the present study was to identify sensitive developmental periods for estrogenic endocrine disruption in the northern leopard frog (Rana pipiens) using short, targeted exposures to the synthetic estrogen, ethinylestradiol (EE2). Post-hatch tadpoles (Gosner stage 27) were exposed over five distinct periods of metamorphosis: early (stage 27-30), mid (stage 30-36), early and mid (stage 27-36), late (stage 36-42), and the entire metamorphic period (chronic; stage 27-42). For each period, animals were sampled immediately following the EE2 exposure and at metamorphic climax (stage 42). The effects of EE2 on metamorphic development and sex differentiation were assessed through measures of length, weight, developmental stage, days to metamorphosis, sex ratios and incidence of gonadal intersex. Our results show that tadpoles exposed to EE2 during mid-metamorphosis were developmentally delayed immediately following exposure and took 2 weeks longer to reach metamorphic climax. In the unexposed groups, there was low proportion (0.15) of intersex tadpoles at stage 30 and gonads appeared to be morphologically distinct (male and female) in all individuals by stage 36. Tadpoles exposed early in development displayed a strong female-biased sex ratio compared to the controls. Moreover, these effects were also seen at metamorphic climax, approximately 2-3 months after the exposure period, demonstrating that transient early life-stage exposure to estrogen can induce effects on the reproductive organs that persist into the beginning of adult life-stages.

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

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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...

Bio-historia

OpenAIRE

Réaumur, René-Antoine Ferchault de; Aguiló, F. de S.

2012-01-01

Memorias sobre las ranas (1) (el apareamiento de las ranas) (2) 1736 (Inédito) (3) / memorias sobre los sapos. Sapos de agua (9) (10 de abril de 1740) (Inédito). Versión y notas del Prof. F. de S. Aguiló

Effect of loach consumption on the reproduction of giant water bug Kirkaldyia deyrolli: dietary selection, reproductive performance, and nutritional evaluation

OpenAIRE

Ohba, Shin-ya; Izumi, Yohei; Tsumuki, Hisaaki

2012-01-01

Rice fields provide major habitats for lentic aquatic insects including the giant water bug Kirkaldyia (=Lethocerus) deyrolli (Heteroptera: Belostomatidae) in Japan. Previous researchers have emphasized that conserving populations of the frogs, Hyla japonicus and Rana nigromaculata, is very important for preserving K. deyrolli because these frogs were found to be a major component of the diet of K. deyrolli adults. However, these previous studies were carried out in rice fields with no loache...

Effects of changing climate on aquatic habitat and connectivity for remnant populations of a wide-ranging frog species in an arid landscape.

Science.gov (United States)

Pilliod, David S; Arkle, Robert S; Robertson, Jeanne M; Murphy, Melanie A; Funk, W Chris

2015-09-01

Amphibian species persisting in isolated streams and wetlands in desert environments can be susceptible to low connectivity, genetic isolation, and climate changes. We evaluated the past (1900-1930), recent (1981-2010), and future (2071-2100) climate suitability of the arid Great Basin (USA) for the Columbia spotted frog (Rana luteiventris) and assessed whether changes in surface water may affect connectivity for remaining populations. We developed a predictive model of current climate suitability and used it to predict the historic and future distribution of suitable climates. We then modeled changes in surface water availability at each time period. Finally, we quantified connectivity among existing populations on the basis of hydrology and correlated it with interpopulation genetic distance. We found that the area of the Great Basin with suitable climate conditions has declined by approximately 49% over the last century and will likely continue to decline under future climate scenarios. Climate conditions at currently occupied locations have been relatively stable over the last century, which may explain persistence at these sites. However, future climates at these currently occupied locations are predicted to become warmer throughout the year and drier during the frog's activity period (May - September). Fall and winter precipitation may increase, but as rain instead of snow. Earlier runoff and lower summer base flows may reduce connectivity between neighboring populations, which is already limited. Many of these changes could have negative effects on remaining populations over the next 50-80 years, but milder winters, longer growing seasons, and wetter falls might positively affect survival and dispersal. Collectively, however, seasonal shifts in temperature, precipitation, and stream flow patterns could reduce habitat suitability and connectivity for frogs and possibly other aquatic species inhabiting streams in this arid region.

Effects of changing climate on aquatic habitat and connectivity for remnant populations of a wide-ranging frog species in an arid landscape

Science.gov (United States)

Pilliod, David S.; Arkle, Robert S.; Robertson, Jeanne M; Murphy, Melanie; Funk, W. Chris

2015-01-01

Amphibian species persisting in isolated streams and wetlands in desert environments can be susceptible to low connectivity, genetic isolation, and climate changes. We evaluated the past (1900–1930), recent (1981–2010), and future (2071–2100) climate suitability of the arid Great Basin (USA) for the Columbia spotted frog (Rana luteiventris) and assessed whether changes in surface water may affect connectivity for remaining populations. We developed a predictive model of current climate suitability and used it to predict the historic and future distribution of suitable climates. We then modeled changes in surface water availability at each time period. Finally, we quantified connectivity among existing populations on the basis of hydrology and correlated it with interpopulation genetic distance. We found that the area of the Great Basin with suitable climate conditions has declined by approximately 49% over the last century and will likely continue to decline under future climate scenarios. Climate conditions at currently occupied locations have been relatively stable over the last century, which may explain persistence at these sites. However, future climates at these currently occupied locations are predicted to become warmer throughout the year and drier during the frog's activity period (May – September). Fall and winter precipitation may increase, but as rain instead of snow. Earlier runoff and lower summer base flows may reduce connectivity between neighboring populations, which is already limited. Many of these changes could have negative effects on remaining populations over the next 50–80 years, but milder winters, longer growing seasons, and wetter falls might positively affect survival and dispersal. Collectively, however, seasonal shifts in temperature, precipitation, and stream flow patterns could reduce habitat suitability and connectivity for frogs and possibly other aquatic species inhabiting streams in this arid region.

A new parameterization for integrated population models to document amphibian reintroductions.

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Duarte, Adam; Pearl, Christopher A; Adams, Michael J; Peterson, James T

2017-09-01

Managers are increasingly implementing reintroduction programs as part of a global effort to alleviate amphibian declines. Given uncertainty in factors affecting populations and a need to make recurring decisions to achieve objectives, adaptive management is a useful component of these efforts. A major impediment to the estimation of demographic rates often used to parameterize and refine decision-support models is that life-stage-specific monitoring data are frequently sparse for amphibians. We developed a new parameterization for integrated population models to match the ecology of amphibians and capitalize on relatively inexpensive monitoring data to document amphibian reintroductions. We evaluate the capability of this model by fitting it to Oregon spotted frog (Rana pretiosa) monitoring data collected from 2007 to 2014 following their reintroduction within the Klamath Basin, Oregon, USA. The number of egg masses encountered and the estimated adult and metamorph abundances generally increased following reintroduction. We found that survival probability from egg to metamorph ranged from 0.01 in 2008 to 0.09 in 2009 and was not related to minimum spring temperatures, metamorph survival probability ranged from 0.13 in 2010-2011 to 0.86 in 2012-2013 and was positively related to mean monthly temperatures (logit-scale slope = 2.37), adult survival probability was lower for founders (0.40) than individuals recruited after reintroduction (0.56), and the mean number of egg masses per adult female was 0.74. Our study is the first to test hypotheses concerning Oregon spotted frog egg-to-metamorph and metamorph-to-adult transition probabilities in the wild and document their response at multiple life stages following reintroduction. Furthermore, we provide an example to illustrate how the structure of our integrated population model serves as a useful foundation for amphibian decision-support models within adaptive management programs. The integration of multiple, but

Low levels of the herbicide atrazine alter sex ratios and reduce metamorphic success in Rana pipiens tadpoles raised in outdoor mesocosms.

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Langlois, Valérie S; Carew, Amanda C; Pauli, Bruce D; Wade, Michael G; Cooke, Gerard M; Trudeau, Vance L

2010-04-01

There are conflicting reports regarding the effects of atrazine (ATZ) on amphibian development. Therefore, further studies are needed to examine the potential mechanisms of action of ATZ in amphibians. Our aim in this study was to determine whether low concentrations of ATZ affect gonadal development and metamorphosis in the Northern leopard frog, Rana pipiens. Tadpoles were exposed in outdoor mesocosms to nominal concentrations of 0.1 and 1.8 microg/L of formulated ATZ from Gosner stage 27 (G27) to metamorphic climax (G42). Exposure to 17alpha-ethinylestradiol (EE2; 1.5 microg/L) provided a positive control for induction of testicular oocytes in males. Endocrine-related gene expression and gonadal histopathology were examined at G42 and in a subset of premetamorphic G34 tadpoles that failed to metamorphose. Gonadal gross morphology revealed that the 1.8-microg/L ATZ treatment produced 20% more females compared with the control. Histologic analysis revealed that 22% of EE2-treated males had testicular oocytes, whereas none were observed in any animals from the control or either ATZ groups. ATZ increased brain estrogen receptor alpha mRNA to 2.5 times that of the control at premetamorphosis and altered liver levels of 5beta-reductase activity at metamorphosis. In contrast, brain aromatase mRNA level and activity did not change. ATZ treatments significantly reduced metamorphic success (number of animals reaching metamorphosis) without affecting body weight, snout-vent length, or age at metamorphosis. Gene expression analysis indicated that ATZ decreased the expression of deiodinase type 3 in the tail at premetamorphosis. Our study indicates that exposure to low concentrations of ATZ in experimental mesocosms alters gonadal differentiation and metamorphosis in developing R. pipiens.

Journal of Genetics | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Genetics. RANA GOPAL SINGH. Articles written in Journal of Genetics. Volume 96 Issue 6 December 2017 pp 885-893 RESEARCH ARTICLE. Mutational screening of PKD2 gene in the north Indian polycystic kidney disease patients revealed 28 genetic variations · SONAM RAJ RANA GOPAL ...

Resonance – Journal of Science Education | Indian Academy of ...

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education. Shubashis Rana. Articles written in Resonance – Journal of Science Education. Volume 22 Issue 7 July 2017 pp 659-676 General Article. Second Law, Landauer's Principle and Autonomous Information Machine · Shubashis Rana A M Jayannavar · More Details ...

Bio-historia

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René-Antoine Ferchault de Réaumur

1951-08-01

Full Text Available Memorias sobre las ranas (1 (el apareamiento de las ranas (2 1736 (Inédito (3 / memorias sobre los sapos. Sapos de agua (9 (10 de abril de 1740 (Inédito. Versión y notas del Prof. F. de S. Aguiló

Coding of amplitude-modulated signals in the cochlear nucleus of a grass frog

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Bibikov, N. G.

2002-07-01

To study the mechanisms that govern the coding of temporal features of complex sound signals, responses of single neurons located in the dorsal nucleus of the medulla oblongata (the cochlear nucleus) of a curarized grass frog ( Rana temporaria) to pure tone bursts and amplitude modulated tone bursts with a modulation frequency of 20 Hz and modulation depths of 10 and 80% were recorded. The carrier frequency was equal to the characteristic frequency of a neuron, the average signal level was 20 30 dB above the threshold, and the signal duration was equal to ten full modulation periods. Of the 133 neurons studied, 129 neurons responded to 80% modulated tone bursts by discharges that were phase-locked with the envelope waveform. At this modulation depth, the best phase locking was observed for neurons with the phasic type of response to tone bursts. For tonic neurons with low characteristic frequencies, along with the reproduction of the modulation, phase locking with the carrier frequency of the signal was observed. At 10% amplitude modulation, phasic neurons usually responded to only the onset of a tone burst. Almost all tonic units showed a tendency to reproduce the envelope, although the efficiency of the reproduction was low, and for half of these neurons, it was below the reliability limit. Some neurons exhibited a more efficient reproduction of the weak modulation. For almost half of the neurons, a reliable improvement was observed in the phase locking of the response during the tone burst presentation (from the first to the tenth modulation period). The cooperative histogram of a set of neurons responding to 10% modulated tone bursts within narrow ranges of frequencies and intensities retains the information on the dynamics of the envelope variation. The data are compared with the results obtained from the study of the responses to similar signals in the acoustic midbrain center of the same object and also with the psychophysical effect of a differential

Journal of Earth System Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Earth System Science. R S Rana. Articles written in Journal of Earth System Science. Volume 122 Issue 2 April 2013 pp 289-307. Palynostratigraphy and depositional environment of Vastan Lignite Mine (Early Eocene), Gujarat, western India · M R Rao Ashok Sahni R S Rana Poonam Verma.

Effects of ultraviolet radiation on life-history stages of anurans from Ontario, Canada

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Grant, K.P.; Licht, L.E. [York Univ., Toronto, ON (Canada)

1995-12-01

The effects of ultraviolet radiation on life-history stages of anurans Bufo americanus, Hyla versicolor, Rana clamitans, and Rana sylvatica were tested. Eggs and larvae were not affected by uv-a at double normal outdoor levels. R. sylvatica embryos exposed to 30 minutes or more of artificially high intensity uv-b levels died. There was no effect on hatching levels for artificially high exposures of uv-b radiation for less than 15 minutes. A greater proportion of abnormal embryos occurred after exposure to 10 or 15 minutes of artificially high intensity treatment at 12 degree Celsius than at 20 degrees Celsius. Only larval R. clamitans showed some level of tolerance of artificially high uv-b levels. Ecologically relevant doses of uv-b had no effect on the developmental period of B. americanus, H. versicolor, and R. sylvatica. Older B. americanus exposed for the same length of time had higher survivorship than younger animals. The role of uv radiation in the presumed decline of amphibian populations was also discussed. 7 tabs., 43 refs.

Alteration of the hypothalamic-pituitary-gonadal axis in estrogen- and androgen-treated adult male leopard frog, Rana pipiens

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Jones Jeremy T

2005-01-01

Full Text Available Abstract Background Gonadal steroids, in particular 5 alpha-dihydrotestosterone (DHT and 17 beta-estradiol (E2, have been shown to feed back on the hypothalamic-pituitary-gonadal (HPG axis of the ranid frog. However, questions still remain on how DHT and E2 impact two of the less-studied components of the ranid HPG axis, the hypothalamus and the gonad, and if the feedback effects are consistently negative. Thus, the goal of the study was to examine the effects of DHT and E2 upon the HPG axis of the gonadally-intact, sexually mature male leopard frogs, Rana pipiens. Methods R. pipiens were implanted with silastic capsules containing either cholesterol (Ch, a control, DHT, or E2 for 10 or 30 days. At each time point, steroid-induced changes in hypothalamic GnRH and pituitary LH concentrations, circulating luteinizing hormone (LH, and testicular histology were examined. Results Frogs implanted with DHT or E2 for 10 days did not show significant alterations in the HPG axis. In contrast, frogs implanted with hormones for 30 days had significantly lower circulating LH (for both DHT and E2, decreased pituitary LH concentration (for E2 only, and disrupted spermatogenesis (for both DHT and E2. The disruption of spermatogenesis was qualitatively similar between DHT and E2, although the effects of E2 were consistently more potent. In both DHT and E2-treated animals, a marked loss of all pre-meiotic germ cells was observed, although the loss of secondary spermatogonia appeared to be the primary cause of disrupted spermatogenesis. Unexpectedly, the presence of post-meiotic germ cells was either unaffected or enhanced by DHT or E2 treatment. Conclusions Overall, these results showed that both DHT and E2 inhibited circulating LH and disrupted spermatogenesis progressively in a time-dependent manner, with the longer duration of treatment producing the more pronounced effects. Further, the feedback effects exerted by both steroid hormones upon the HPG axis were

A stockpile of ova in the grass frog Rana temporaria is established once for the life span. Do ovaries in amphibians and in mammals follow the same evolutionary strategy?

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Ogielska, Maria; Kotusz, Agnieszka; Augustyńska, Renata; Ihnatowicz, Jerzy; Paśko, Łukasz

2013-04-01

Most anuran amphibians produce high numbers of eggs during several consecutive breeding seasons. The question is still open whether oocytes are formed anew as a result of oogonial proliferation after each spawning or the definitive pool of oocytes is established during the juvenile period and is sufficient for the whole reproductive life span of a female. Our quantitative studies show that primary oogonia in adult female frogs can proliferate, but they fail to differentiate further and do not enter meiosis, and thereby there is no supplementation of new generations of oocytes after each spawning. Ovaries of one-year-old grass frogs contain (median) 53,447 diplotene oocytes, in two-years-old frogs this number decreased to 33,583 and eventually reached 25,679 in virgin mature females. More than 50% decrease in the total oocyte number was accompanied by massive degeneration (atresia) of oocytes. The final number of oocytes in a female forms a stock for 11-12 breeding seasons and exceeds the number of eggs produced during the potential reproductive life span of this species. The phylogenetic context of oocyte recruitment modes in the major clades of vertebrates is discussed in respect to their ability to replenish the stock (a renewable stock in ovaries named "open" vs. a non-renewable stock in ovaries named "closed"). Copyright © 2013 Wiley Periodicals, Inc.

Una especie nueva de rana arbórea del género Hyloscirtus (Amphibia: Anura: Hylidae de la Cordillera del Cóndor

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Ana Almendáriz

2014-01-01

Full Text Available Las ranas ecuatorianas del género Hyloscirtus incluyen 16 especies descritas, de las cuales 11 pertenecen al grupo H. larinopygion. Su distribución se limita a los flancos de la Cordillera de los Andes, tanto al oriente como al occidente. Una evaluación de la herpetofauna en el sector meridional de la Cordillera del Cóndor (bosques montanos sobre mesetas de arenisca en la provincia de Zamora Chinchipe, Ecuador, condujo al descubrimiento de una especie nueva del grupo que describimos aquí como Hyloscirtus condor sp. nov.; se analizan los renacuajos, las llamadas de anuncio y se estima las relaciones filogenéticas de la especie nueva y de las especies relacionadas en base a nuevas secuencias de los genes mitocondriales 12S, tRNA Val y 16S, con un total de hasta 2508 bp. Los resultados muestran que el grupo H. larinopygion está conformado por dos clados, uno distribuido en los Andes norte y centro de Ecuador y el otro al sur. La nueva especie pertenece al clado sur y es hermana de H. tapichalaca y de una especie aparentemente no descrita de la Provincia Morona Santiago. La especie nueva difiere de sus congéneres por su patrón de coloración dorsal, que consiste de puntos amarillo obscuro en un fondo canela. Es la especie más grande del grupo H. larinopygion y comparte con H. tapichalaca la presencia de una espina prepólica grande y curvada y brazos hipertrofiados. La especie nueva habita un área remota y bien conservada de la Cordillera del Cóndor. El descubrimiento de ésta y otras especies nuevas del mismo lugar denota la importancia biológica del área y motivan al desarrollo de planes de conservación.

ENVIRONMENTAL AND AESTHETIC THOUGHT AROUNDTHE IDEA OF AN ETHOS-FROG-CHILD.

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Juliana Paola Beltrán Molina

2015-10-01

Full Text Available El presente escrito es resultado de un proceso de investigación en pensamiento ambiental en clave estética en torno a las ranas, en configuración simbólica de la tríada ethos/rana/niño, y en alternancia a las maneras como son concebidas biológicamente en su objetivación. Para su realización se contó con la participación de niños de la Institución Educativa Rural Hojas Anchas, del municipio de Circasia, departamento del Quindío, quienes relataron sobre ellas, desde su cercanía y percepción a través de escrituras y expresión pictórica. Así, sus relatos fueron organizados en tendencias por lo que dicen, por lo que anuncian, y son el punto de partida para la construcción de emergencias de Pensamiento Ambiental para su consideración en clave estética. En consecuencia, se construyen cuatro tendencias que se enuncian así: “un abrazo fecundo de los cuerpos que se contorsionan”; “vestiduras de una rana: coqueteo entre amantes o advertencia letal”; “la rana y el agua: la vida en su potencia y su latencia” y “naturaleza hecha rana: reflejos de una fragilidad corpórea”. A partir de estos enunciados, se construyen derivas de pensamiento de un ethos/rana/niño en deseo de su disolución simbólica y en resistencia a su cosificación, que a su vez, aportan para repensar la vida en el ámbito del aula. En este sentido, se acoge la obra pictórica de la artista mexicana Teresa Irene Barrera, entre otros autores del pensamiento ambiental.

Don't get the blues: conspicuous nuptial colouration of male moor frogs (Rana arvalis) supports visual mate recognition during scramble competition in large breeding aggregations.

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Sztatecsny, Marc; Preininger, Doris; Freudmann, Anita; Loretto, Matthias-Claudio; Maier, Franziska; Hödl, Walter

2012-12-01

Conspicuous male colouration is expected to have evolved primarily through selection by female choice. In what way conspicuous colours could be advantageous to males scrambling for mates remains largely unknown. The moor frog (Rana arvalis) belongs to the so-called explosive breeders in which spawning period is short; intrasexual competition is strong, and males actively search and scramble for females. During breeding, male body colouration changes from a dull brown (similar to females) to a conspicuous blue, and we wanted to test if male blueness influences mating success or facilitates male mate recognition. To do so, we first measured the colour of mated and non-mated males using a spectrophotometer. In an experiment, we then analysed interactions of actual male moor frogs in natural spawning aggregations with a brown (resembling a female or a non-breeding male) and a blue model frog. Mated and non-mated males did not differ in colouration, suggesting that female choice based on colour traits was unlikely. In our behavioural experiment, male moor frogs spent significantly more time in contact and in amplexus with the brown model than with the blue model. Our results suggest that the nuptial colouration in moor frogs can act as a new type of visual signal in anurans evolved to promote instantaneous mate recognition allowing males to quickly move between rivals while scrambling for females. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00265-012-1412-6) contains supplementary material, which is available to authorized users.

Development of Hepatozoon caimani (Carini, 1909 Pessôa, De Biasi & De Souza, 1972 in the Caiman Caiman c. crocodilus, the frog Rana catesbeiana and the mosquito Culex fatigans

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Lainson Ralph

2003-01-01

Full Text Available The sporogony of Hepatozoon caimani has been studied, by light microscopy, in the mosquito Culex fatigans fed on specimens of the caiman Caiman c. crocodilus showing gametocytes in their peripheral blood. Sporonts iniciate development in the space between the epithelium of the insect gut and the elastic membrane covering the haemocoele surface of the stomach. Sporulating oocysts are clustered on the gut, still invested by the gut surface membrane. Fully mature oocysts were first seen 21 days after the blood-meal. No sporogonic stages were found in some unidentified leeches fed on an infected caiman, up to 30 days following the blood-meal. When mosquitoes containing mature oocysts were fed to frogs (Leptodactylus fuscus and Rana catesbeiana, cysts containing cystozoites developed in the internal organs, principally the liver. Feeding these frogs to farm-bred caimans resulted in the appearance of gametocytes in their peripheral blood at some time between 59 and 79 days later, and the development of tissue cysts in the liver, spleen, lungs and kidneys. Transmission of the parasite was also obtained by feeding young caimans with infected mosquitoes and it is suggested that both methods occur in nature. The finding of similar cysts containing cystozoites in the semi-aquatic lizard Neusticurus bicarinatus, experimentally fed with infected C. fatigans, suggests that other secondary hosts may be involved.

Desempenho zootécnico e tabela de alimentação de girinos de rã-touro (Rana catesbeiana criados no sistema anfigranja

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Lima Samuel Lopes

2003-01-01

Full Text Available Objetivou-se com a execução deste trabalho avaliar, em nível de campo, o desempenho zootécnico de girinos de rã-touro (Rana catesbeiana criados em ranários comerciais que utilizam o sistema anfigranja, e simultaneamente estimar os valores de consumo diário de ração para compor uma tabela de referência para a alimentação dos animais. Os resultados encontrados nas unidades de observações monitoradas (aproximadamente 249 mil animais atingiram os seguintes índices médios: a mortalidade (em % variou de: 0,7 a 35,2 (média 5,9%; o ganho de peso (g. p/dia: de 0,03 a 0,22 (média 0,11 g/dia; e a conversão alimentar: de 0,92 a 2,75 : 1; (média 1,50 : 1. Comparados com dados preliminares, tais resultados indicam uma significativa otimização dos índices zootécnicos, demonstrando que houve um relativo ganho de produtividade com o aperfeiçoamento das técnicas de manejo implementadas. A redução do valor médio da conversão alimentar aparente foi provocada principalmente pelo adequado uso da tabela de referência, cujos valores foram ratificados durante o trabalho de monitoramento das unidades. Tal tabela possibilita o cálculo da quantidade de alimento a ser oferecido diariamente, baseado nos peso médio dos girinos e na estimativa do percentual de consumo, para temperatura da água entre 18 a 29 graus centígrados, (girinos de 0,1 a 26 gramas de peso médio.

Abundancia relativa y uso de microhábitat de la rana Geobatrachus walkeri (Anura: Strabomantidae en dos hábitats en Sierra Nevada de Santa Marta, Colombia

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Vera Martínez Baños

2011-06-01

Full Text Available La rana Geobatrachus walkeri pertenece a un género monotípico y endémico del área de San Lorenzo, Sierra Nevada de Santa Marta, Colombia. La especie habita en el bosque secundario natural y en una plantación de pino (dominada por Pinus patula. Para comparar la abundancia relativa y el uso del microhábitat en estos dos hábitat y durante los períodos de máxima y mínima precipitación, se distribuyeron aleatoriamente 30 cuadrantes en cada bosque sobre los que se registraron el número de individuos y los microhábitats ocupados. Además se reconocieron otros aspectos de la historia natural mediante muestreo por encuentros casuales (VES, se incluye en los dos hábitats áreas no muestreadas por los cuadrantes. La mayor abundancia de ranas se obtuvo en la plantación de pino y durante la época de lluvias. El microhábitat más usado fue la hojarasca de pino. Geobatrachus walkeri es una especie exitosa en las plantaciones de pino, asociada permanentemente a su hojarasca en donde parece desarrollar todo su ciclo de vida. Las claras modificaciones derivadas de la introducción de las plantaciones de pino en el suelo y el agua, parecen no haber afectado la supervivencia y mantenimiento exitoso de esta especie categorizada como en peligro de extinción.Relative abundance and microhabitat use by the frog Geobatrachus walkeri (Anura:Strabomantidae in two habitats of Sierra Nevada de Santa Marta, Colombia. 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

Supplementary studies of Pleurogenoides medians (Digenea: Lecithodendriidae infecting the Marsh frog Rana Ridibunda (Amphibia: Ranidae in Egypt

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Rewaida Abdel-Gaber

2017-06-01

Full Text Available Pleurogenoides medians, a digenean lecithodendriid trematode, parasitize numerous aquatic vertebrate species including frogs, freshwater fish, urodeles and anurans. In the present study, a total of 190 out of 300 (63.33% marsh frogs Rana Ridibunda were found to be infected with this digenean parasite. The highest percentage of infection was recorded in winter reaching 93.33%, and the lowest value was recorded to be 6.66% during summer. Prevalence and intensity of infection were positively correlated with the host size. Host sex showed no effect in this respect. Morphological studies based on light and scanning electron microscopy revealed that the adult worms characterized by small body size measured 1.980–2.430 (2.205 ± 0.1 mm long and 0.870–1.20 (9.87 ± 0.01 mm wide with spines of similar size distributed all over the body surface; oral sucker is sub-terminal and measured 0.180–0.230 (0.203 ± 0.01 mm long and 0.120–0.180 (0.150 ± 0.01 mm wide; ventral sucker is smaller than the oral sucker, post-ovarian located at 1/3 level from the anterior end and measured 0.080–0.102 (0.090 ± 0.001 mm long and 0.100–0140 (0.120 ± 0.001 mm wide; two symmetrical testes were located near the cecal termination on both sides of the ventral sucker, measured 0.153–0.193 (0.176 ± 0.01 mm long and 0.160–0.192 (0.175 ± 0.01 mm wide; pre-acetabular ovary was present and measured 0.130–0.150 (0.140 ± 0.01 mm long and 0.100–0.130 (0.120 ± 0.01 mm wide; vitellaria are extra-caecal and extended from the level of the pharynx to a level slightly beyond the ovary. By comparing the recovered parasite with different species of the same genus from different hosts having different localities, it was found that the present species morphometrically more or less different from the comparable species and the only similar species was P. medians described previously from the common toad Bufo bufo by having all similar

Histomorfología de la atrición en dientes temporarios

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Melisa R Lezcano

Full Text Available Resumen En la Facultad de Odontología de la Universidad Nacional del Nordeste, provincia de Corrientes, Argentina, se desarrolló un trabajo de investigación en el cual se estudiaron las características histológicas que presentaban el esmalte y la dentina de piezas dentarias temporarias bajo el proceso fisiológico de la atrición. Para dicho estudio, se obtuvieron 25 piezas dentarias temporarias de pacientes que concurrieron a la Cátedra de Odontopediatría para su atención. Las muestras fueron protocolizadas y clasificadas según la escala de desgaste dentario de Gerasimov modificada. Las piezas dentarias se procesaron mediante la técnica de desgaste para su observación al microscopio óptico, determinándose que el 48% de los casos el desgaste correspondía a grado I, el 36% al grado II y el resto al grado III. En los casos que afectó al esmalte únicamente se observó la sección de los prismas del esmalte. Cuando afectó esmalte y dentina en los grados II y III de la escala se observan tanto casos de dentina esclerótica como de trayectos muertos

Avoidance response of juvenile Pacific treefrogs to chemical cues of introduced predatory bullfrogs.

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Chivers, D P; Wildy, E L; Kiesecker, J M; Blaustein, A R

2001-08-01

Bullfrogs (Rana catesbeiana), native to eastern North America, were introduced into Oregon in the 1930's. Bullfrogs are highly efficient predators that are known to eat a variety of prey including other amphibians. In laboratory experiments, we investigated whether juvenile Pacific treefrogs (Hyla regilla) recognize adult bullfrogs as a predatory threat. The ability of prey animals to acquire recognition of an introduced predator has important implications for survival of the prey. We found that treefrogs from a population that co-occurred with bullfrogs showed a strong avoidance of chemical cues of bullfrogs. In contrast, treefrogs from a population that did not co-occur with bullfrogs, did not respond to the bullfrog cues. Additional experiments showed that both populations of treefrogs use chemical cues to mediate predation risk. Treefrogs from both populations avoided chemical alarm cues from injured conspecifics.

DIET OF DIRECT-DEVELOPING FROGS (ANURA: CRAUGASTORIDAE: Pristimantis FROM THE ANDES OF WESTERN COLOMBIA

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Juan Carlos GARCIA-R

2015-01-01

Estudiamos la dieta de 15 especies de ranas montanas del género Pristimantis (Craugastoridae en la Cordillera Occidental de Colombia para determinar su variación, amplitud y traslape de nicho. En los contenidos estomacales e intestinales de 154 especímenes se identificaron 499 presas que fueron organizadas en 74 categorías diferentes. Las 15 categorías de presas más comunes representaron el 65 % de la dieta. Las familias de invertebrados Isotomidae, Chironomidae, Formicidae y Tipulidae fueron las más abundantes, representando el 32 % de la dieta de las ranas. Diez de las 15 especies de ranas presentaron al menos un ítem de Araneae. Coleoptera y Tipulidae fueron otras categorías frecuentemente encontradas en los tractos digestivos de las ranas (nueve especies de ranas presentaron estos ítems,  seguidas de Acari y Carabidae (ocho especies. En general, los escarabajos fueron encontrados en los tractos gastrointestinales de todas las especies, excepto en P. quantus, pero este resultado debe tratarse con precaución porque solo un individuo de esta especie fue capturado. Pristimantis hectus mostró una dieta especializada consumiendo principalmente dípteros de la familia Chironomidae, mientras que las especies restantes mostraron una dieta generalista. Pristimantis palmeri presentó superposiciones de nicho con P. erythropleura (Фjk = 0,69, P. myops (Фjk = 0,64, y P. orpacobates (Фjk = 0,64. Nuestros resultados sugieren que la mayoría de las especies estudiadas son generalistas que se alimentan de manera oportunista de dípteros, arácnidos, colémbolos, coleópteros e himenópteros. Aquí, reportamos la dieta de especies montanas de Pristimantis y discutimos los resultados con datos de otros estudios en especies relacionadas de regiones montanas y tierras bajas

Changes in behavioural responses to infrastructure affect local and regional connectivity – a simulation study on pond breeding amphibians

DEFF Research Database (Denmark)

Pontoppidan, Maj-Britt; Nachman, Gøsta Støger

2013-01-01

An extensive and expanding infrastructural network destroys and fragments natural habitat and has detrimental effect on abundance and population viability of many amphibian species. Roads function as barriers in the landscape. They separate local populations from each other or prevent access...... to necessary resources. Therefore, road density and traffic intensity in a region may have severe impact on regional as well as local connectivity. Amphibians may be able to detect and avoid unsuitable habitat. Individuals’ ability to avoid roads can reduce road mortality but at the same time road...... avoidance behaviour, can increase the barrier effect of the road and reduce connectivity. We use an individual based model to explore how changes in road mortality and road avoidance behaviour affect local and regional connectivity in a population of Moor frogs (Rana arvalis). The results indicate that road...

Effects of rapid shortening on rate of force regeneration and myoplasmic [Ca2+] in intact frog skeletal muscle fibres

Science.gov (United States)

Vandenboom, R; Claflin, D R; Julian, F J

1998-01-01

The effect of rapid shortening on rate of force regeneration (dF/dtR) was examined in single, intact frog (Rana temporaria) skeletal muscle fibres (3·0 °C). Step releases leading to unloaded shortening were applied after 500 ms of stimulation, during the plateau of an isometric tetanus. Initial mean sarcomere length ranged from 2·05 to 2·35 μm; force regeneration after shortening was at 2·00 μm.Values for dF/dtR following a 25 nm half-sarcomere−1 release were 3·17 ± 0·17 (mean ± s.e.m., n= 8) times greater than the initial rate of rise of force before release (dF/dtI). As release size was increased from 25 to 175 nm half-sarcomere−1, the relationship between release size and dF/dtR decreased sharply before attaining a plateau value that was 1·34 ± 0·09 times greater than dF/dtI. Despite wide variations in dF/dtR, the velocity of unloaded shortening remained constant (2·92 ± 0·08 μm half-sarcomere−1 s−1; n= 8) for the different release amplitudes used in this study.To investigate its role in the attenuation of dF/dtR with increased shortening, the effects of rapid ramp (constant velocity) shortening on intracellular free Ca2+ concentration ([Ca2+]i) were monitored using the Ca2+-sensitive fluorescent dye furaptra. Compared with an isometric contraction, rapid fibre shortening was associated with a transient increase in [Ca2+]i while force regeneration after shortening was associated with a transient reduction in [Ca2+]i. The greatest reductions in [Ca2+]i were associated with the largest amplitude ramps.Cross-bridge-mediated modifications of the Ca2+ affinity of troponin C (TnC) may explain the fluctuations in [Ca2+]i observed during and after ramps. Associated fluctuations in TnC Ca2+ occupancy could play a role in the reduction of dF/dtR with increasing release size. PMID:9679172

Neogene amphibians and reptiles (Caudata, Anura, Gekkota, Lacertilia, and Testudines) from the south of Western Siberia, Russia, and Northeastern Kazakhstan.

Science.gov (United States)

Vasilyan, Davit; Zazhigin, Vladimir S; Böhme, Madelaine

2017-01-01

included Eastern Palaearctic taxa (e.g. Salamandrella , Tylototriton , Bufotes viridis ). For several taxa (e.g. Mioproteus, Hyla, Bombina , Rana temporaria ), the Western Siberian occurrences represented their most eastern Eurasian records. The most diverse collection of fossil remains was found in the Middle Miocene. Less diversity has been registered towards the Early Pleistocene, potentially due to the progressive cooling of the climate in the Northern Hemisphere. The results of our study showed higher-amplitude changes of precipitation development in Western Siberia from the Early Miocene to the Pliocene, than previously assumed.

A natriferic principle other than arginine-vasotocin in the frog neuro hypophysis (1961); Un principe natriferique autre que l'arginine vasotocine dans la neuro hypophyse de la grenouille (1961)

Energy Technology Data Exchange (ETDEWEB)

Morel, F; Maetz, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Acher, R; Chauvet, J; Lenci, M T [Faculte des Sciences de Paris, 75 (France)

1961-07-01

In the neurohypophysis of Rana esculenta there exists, in addition to vasotocin, an unknown active principle which accounts for approximately half of the total natriferic activity of the gland. This principle is not found in chickens. (authors) [French] II existe dans la neurohypophyse de Rana esculenta, en plus de la vasotocine, un principe actif inconnu qui rend compte approximativement de la moitie de l'activite natriferique totale de la glande. Ce principe ne se retrouve pas chez le poulet. (auteurs)

Using occupancy models to understand the distribution of an amphibian pathogen, Batrachochytrium dendrobatidis

Science.gov (United States)

Adams, Michael J.; Chelgren, Nathan; Reinitz, David M.; Cole, Rebecca A.; Rachowicz, L.J.; Galvan, Stephanie; Mccreary, Brome; Pearl, Christopher A.; Bailey, Larissa L.; Bettaso, Jamie B.; Bull, Evelyn L.; Leu, Matthias

2010-01-01

Batrachochytrium dendrobatidis is a fungal pathogen that is receiving attention around the world for its role in amphibian declines. Study of its occurrence patterns is hampered by false negatives: the failure to detect the pathogen when it is present. Occupancy models are a useful but currently underutilized tool for analyzing detection data when the probability of detecting a species is population, was related to amphibian development stage, day of the year, elevation, and human activities. Batrachochytrium dendrobatidis was found throughout our study area but was only estimated to occur in 53.4% of 78 populations of native amphibians and 66.4% of 40 populations of nonnative Rana catesbeiana tested. We found little evidence to support any spatial hypotheses concerning the probability that the pathogen occurs in a population, but did find evidence of some taxonomic variation. We discuss the interpretation of occupancy model parameters, when, unlike a conventional occupancy application, the number of potential samples or observations is finite.

The Current and Historical Distribution of Special Status Amphibians at the Livermore Site and Site 300

Energy Technology Data Exchange (ETDEWEB)

Hattem, M V; Paterson, L; Woollett, J

2008-08-20

65 surveys were completed in 2002 to assess the current distribution of special status amphibians at the Lawrence Livermore National Laboratory's (LLNL) Livermore Site and Site 300. Combined with historical information from previous years, the information presented herein illustrates the dynamic and probable risk that amphibian populations face at both sites. The Livermore Site is developed and in stark contrast to the mostly undeveloped Site 300. Yet both sites have significant issues threatening the long-term sustainability of their respective amphibian populations. Livermore Site amphibians are presented with a suite of challenges inherent of urban interfaces, most predictably the bullfrog (Rana catesbeiana), while Site 300's erosion issues and periodic feral pig (Sus scrofa) infestations reduce and threaten populations. The long-term sustainability of LLNL's special status amphibians will require active management and resource commitment to maintain and restore amphibian habitat at both sites.

Dengue, Zika y Chikungunya

OpenAIRE

Kantor, Isabel N

2016-01-01

Los responsables de la actual pandemia de Chikungunya (alfavirus), dengue y Zika (flavivirus) son virus trasmitidos por artrópodos, arbovirus. Su importancia aumentó en las Américas en los últimos 20 años. Los vectores principales son Aedes aegypti y A. albopictus. La infección por dengue provee inmunidad duradera al serotipo específico y temporaria a otros tres. La posterior infección por otro serotipo determina mayor gravedad. Existe una vacuna contra dengue registrada, Dengvaxia (Sanofi Pa...

Consecuencias contables de la variación del tipo impositivo por la reforma fiscal del Impuesto sobre Sociedades

OpenAIRE

Rodríguez García, Ferran

2015-01-01

Hablar a estas alturas de la íntima, y frecuentemente molesta para los contables, relación entre contabilidad y fiscalidad puede parecer absurdo. No obstante, aunque no pretendemos descubrir nada nuevo, no es menos cierto que en situaciones de reforma tributaria como la que se avecina se hace mucho más patente esta relación, no por el hecho de que con la reforma vayan a cambiar substancialmente los aspectos relativos a las diferencias permanentes y temporarias a las que ya nos hemos acostumbr...

Electrophoretic pattern of blood serum proteins of some of the vertebrates of Pakistan

International Nuclear Information System (INIS)

Shakoori, Abdul Rauf; Zaheer, Saleem Akhtar; Ahmad, Muhammad Salih.

1976-01-01

The electrophoretic pattern of blood serum proteins of some of the common fishes e.g. Catla catla, Cirrhina mrigala, Channa punctatus, Channa marulius, Wallago attu, Heterop-neustes fossilis; amphibia e.g., Rana tigrina, Rana cyanophlyctis, Bufo melanostictus; reptiles e.g. Varanus bengalensis, Uromastix hardwickii; birds e.g. Columba livia, Gallus domesticus, Passer domestica, Anas platyrhynchos; and mammals e.g. Homo sapiens, Mus musculus, Lepus cuniculus have been described. The mobility of proteins of blood sera has been studied over cellulose acetate paper and then a comparative pattern analysed

First record of the chytrid fungus in Lithobates catesbeianus from Argentina: exotic species and conservation Primer registro del hongo quitridio en Lithobates catesbeianus de Argentina: especies exóticas y conservación

Directory of Open Access Journals (Sweden)

Romina Ghirardi

2011-12-01

Full Text Available Chytridiomycosis, a disease caused by the chytrid fungus Batrachochytrium dendrobatidis (B.d., is recognized as one of the major factors of amphibian decline. Global trade of amphibians has been identified as one of the causes of B.d. spread, involving hundreds of species world wide. In this work we detected the presence of B.d. through histological examination on 5 out of 9 analyzed specimens of bullfrogs (Lithobates catesbeianus from a farm in Santa Fe City (Argentina, deposited since 1993 in the herpetological collection of the Provincial Museum of Natural Sciences "Florentino Ameghino". Our finding represents the oldest record of B.d. for Argentina and the first case of the chytrid fungus infecting the exotic bullfrog in this country. We emphasize the importance of determining and monitoring the distribution and spread of B.d in Argentina, particularly in areas where feral bullfrog populations have already been identified.La quitridiomicosis, enfermedad emergente producida por el hongo Batrachochytrium dendrobatidis (B.d., es reconocida como uno de los factores causantes de la declinación de anfibios. El comercio mundial de anfibios ha sido señalado como una de las fuentes de dispersión de B.d. En este trabajo se detectó la presencia de B.d. en la especie exótica rana toro (Lithobates catesbeianus mediante cortes histológicos en 5 de 9 ejemplares provenientes de un criadero de la ciudad de Santa Fe (Argentina, depositados y conservados desde 1993 en la Colección Herpetológica del Museo Provincial de Ciencias Naturales "Florentino Ameghino". Este registro representa el hallazgo más antiguo de B.d. en Argentina y el primer caso de este hongo en la rana toro exótica en el país; por lo que enfatizamos la importancia de determinar y monitorear la distribución y dispersión de B.d., particularmente en los sitios donde ya se han detectado poblaciones silvestres de rana toro.

Detection of trans-acting factors for hemoglobin switching by cell fusions

International Nuclear Information System (INIS)

Broyles, R.H.; Palmer, J.C.; Smith, D.J.; Ramseyer, T.H.

1986-01-01

The authors have devised protocols for chemically fusing erythroid cells from amphibians of different developmental stages, so that we may study the short-term effects of trans-acting factors on globin gene expression. The authors are performing both homospecifc (Rana x Rana) and heterospecific (Rana x Xenopus) fusions; and they are detecting the expression of specific globin genes with selective radioactive labeling ( 35 S-methionine is incorporated only into adult globins), polyacrylamide gel electrophoresis, monospecific antisera, and cDNA probes that are species-and developmental stage-specific. Their results indicate that: (1) there are factors in tadpole erythroblasts that can reactivate adult Hb synthesis in mature, synthetically-inactive adult RBCs; (2) there are factors in tadpole erythroblasts that can reactivate tadpole globin genes in adult RBCs; and (3) there are factors in adult erythroid cells that apparently activate adult globin genes in tadpole RBCs. These results suggests that erythroid cells from animals of different developmental stages possess different sets of globin gene-specific trans-acting factors which can be studied with a system that exhibits normal developmental Hb switching

Contabilidad del impuesto sobre beneficios y resultado global: relevancia valorativa en el mercado financiero español

OpenAIRE

Zamora Ramírez, Constancio; Moreno Rojas, José; Rueda Torres, Juan Antonio

2014-01-01

La contabilidad del impuesto sobre beneficios ha sido un tema profusamente tratado en la literatura académica y que actualmente se encuentra a la espera de un borrador para su reforma en el seno del International Accounting Standard Board (IASB). Por otro lado, a pesar de que la normativa contable se ha orientado hacia un reconocimiento del efecto impositivo en base a diferencias temporarias, la investigación empírica se ha centrado en el desarrollo de modelos en base al efecto sobre pérdidas...

ENVIRONMENTAL AND AESTHETIC THOUGHT AROUNDTHE IDEA OF AN ETHOS-FROG-CHILD.

OpenAIRE

Juliana Paola Beltrán Molina; Sandra Marcela Walteros Salazar; Carlos Alberto Chacón Ramírez

2015-01-01

El presente escrito es resultado de un proceso de investigación en pensamiento ambiental en clave estética en torno a las ranas, en configuración simbólica de la tríada ethos/rana/niño, y en alternancia a las maneras como son concebidas biológicamente en su objetivación. Para su realización se contó con la participación de niños de la Institución Educativa Rural Hojas Anchas, del municipio de Circasia, departamento del Quindío, quienes relataron sobre ellas, desde su cercanía y percepción...

Contribuciones al estudio de la Parasitología en Colombia

Directory of Open Access Journals (Sweden)

Uribe-Piedrahita César

1947-12-01

Full Text Available 1- Myxobolidae parasito de la vesícula biliar de una Rana de los Llanos Orientales (Resumen: Se observó un Myxobolidae, Myxobolus pfeitteri, parásito de la vesícula biliar de Rana palmipes, habitante de los Llanos orientales de Colombia. Se destaca su papel patógeno.  Creemos que es el primer Myxobolidae descrito en Colombia. / 2- Observaciones sobre un Trichomonas sp. (Resumen: Aechmea bromeliaefolia / Greigia Danielii / Guzmania costaricensis / Guzmania diffusa / Guzmania glomerata / Guzmania minor Mez var / Flammea / Pitcairnia Bakeri / Pitcairnia Barrigae / Pitcairnia costata / Pitcairnia diffusa / Pitcairnia excerta / Pitcairnia lepidopetalon / Pitcairnia squarrosa / Pitcairnia squarrosa var. Colorata / Tillandsia hospitalis / Tillandsia pulchella / Vriesia Hodgei.

Species Diversity and Distribution of Amphibians and Reptiles in Nature Park "Sinite Kamani" in Stara Planina Mt. (Bulgaria

Directory of Open Access Journals (Sweden)

Stanimira R. Deleva

2014-12-01

Full Text Available The current study presents briefly the species composition and distribution of the amphibians and reptiles in the Nature Park "Sinite Kamani" in Stara Planina Mnt. Bulgaria, based on a 2×2 km UTM grid. Between 2012 and 2014, we identified total 20 species (7 amphibians and 13 reptiles. We documented three new amphibian species for the region (Hyla arborea, Rana dalmatina and Rana graeca, which is discovered for the area for the first time and three species of reptiles (Testudo hermanni, Ablepharus kitaibelii and Lacerta trilienata. The contemporary conservation status for each species is presented and conservation threats and problems, specific for the park are discussed.

Acid precipitation studies in Colorado and Wyoming: interim report of surveys of montane amphibians and water chemistry

Science.gov (United States)

Corn, Paul Stephen; Stolzenburg, William; Bury, R. Bruce

1989-01-01

Acid deposition may be detrimental or stressful to native populations of wildlife. Because many species of amphibians breed in shallow ponds created by spring rains or melting snow, they may be particularly vulnerable to the effects of acidification. From 1986 to 1988, we surveyed 105 locations in the central Rocky Mountains where amphibians had been recorded previously, and we found that two species of amphibians had experiences major losses. We found the northern leopard frog (Rana pipiens) at only 4 of 33 (12%) historically known localities, and the boreal toad (Bufo boreas) was present at 10 of 59 (17%) known localities. Three other species have not suffered region-wide declines. Tiger salamanders (Ambystoma tigrinum) and wood frogs (Rana sylvatica) were present at 45% and 69% of known localities respectively, and were observed at several localities were they had not been recorded previously. Chorus frogs (Pseudacris triseriata) suffered a catastrophic decline in population size in one population monitored since 1961, but regionally, this species was observed in 36 of 56 (64%) known localities and in another 19 localities where there were no previous records. Complete water chemistry was recorded for 41 localities, and pH was measured at 110 sites in total. Acid neutralizing capacity, pH, specific conductivity, and cation concentrations were negatively correlated with elevation. However, in mountain ponds and lakes, pH was rarely less than 6.0 during the amphibian breeding season. We tested the tolerance of embryos of the four species of frogs to low pH. The LC50 pH was 4.8 for chorus frogs, 4.4-4.7 for leopard frogs, 4.4-4.5 for boreal toads, and 4.2-4.3 for wood frogs. Survival of wood frog embryos declined when exposed to aluminum concentrations of 100 µg/L or greater, but boreal toad embryos survived exposure to aluminum concentrations of 400 µg/L. Acid deposition does not appear to be a major factor in the decline of leopard frogs and boreal toads

Mortalidad por violencias y su impacto en la esperanza de vida: una comparación entre México y Brasil

OpenAIRE

González-Pérez, Guillermo Julián; Vega-López, María Guadalupe; Souza, Edinilsa Ramos de; Pinto, Liana Wernersbach

2017-01-01

Resumen A partir de datos oficiales, se analizó la mortalidad por violencias (MV):homicidio, suicidio, eventos de intención no determinada e intervención legal, en Brasil y México y su impacto en la esperanza de vida (EV) entre los trienios 2002-04 y 2012-14, y se identificó los grupos etarios en los años de esperanza de vida perdidos (AEVP) por estas causas. Se construyeron tablas de vida abreviadas para los dos países, por sexo, para ambos trienios; esto permitió calcular la EV temporaria e...

Neogene amphibians and reptiles (Caudata, Anura, Gekkota, Lacertilia, and Testudines from the south of Western Siberia, Russia, and Northeastern Kazakhstan

Directory of Open Access Journals (Sweden)

Davit Vasilyan

2017-03-01

, Bombina, Hyla, Bufo bufo, and a small part of this assemblage included Eastern Palaearctic taxa (e.g. Salamandrella, Tylototriton, Bufotes viridis. For several taxa (e.g. Mioproteus, Hyla, Bombina, Rana temporaria, the Western Siberian occurrences represented their most eastern Eurasian records. The most diverse collection of fossil remains was found in the Middle Miocene. Less diversity has been registered towards the Early Pleistocene, potentially due to the progressive cooling of the climate in the Northern Hemisphere. The results of our study showed higher-amplitude changes of precipitation development in Western Siberia from the Early Miocene to the Pliocene, than previously assumed.

Adaptive plasticity of skeletal muscle energetics in hibernating frogs: mitochondrial proton leak during metabolic depression.

Science.gov (United States)

Boutilier, Robert G; St-Pierre, Julie

2002-08-01

The common frog (Rana temporaria) spends the coldest months of each year overwintering in ice-covered ponds where temperatures can vary from 0.5 to 4.0 degrees C. Over the course of a winter season, the animals enter progressively into a state of metabolic depression that relies almost exclusively on aerobic production of ATP. However, if aerobic metabolism is threatened, for example by increasingly hypoxic conditions, decreases in the animal's metabolic rate can reach upwards of 75% compared with the 50% decrease seen during normoxia. Under these conditions, the major proportion of the overall reduction in whole-animal metabolic rate can be accounted for by metabolic suppression of the skeletal muscle (which makes up approximately 40% of body mass). Little is known about the properties of mitochondria during prolonged periods of metabolic depression, so we have examined several aspects of mitochondrial metabolism in the skeletal muscle of frogs over periods of hibernation of up to 4 months. Mitochondria isolated from the skeletal muscle of frogs hibernating in hypoxic water show a considerable reorganisation of function compared with those isolated from normoxic submerged animals at the same temperature (3 degrees C). Both the active (state 3) and resting (state 4) respiration rates of mitochondria decrease during hypoxic, but not normoxic, hibernation. In addition, the affinity of mitochondria for oxygen increases during periods of acute hypoxic stress during normoxic hibernation as well as during long-term hibernation in hypoxic water. The decrease in mitochondrial state 4 respiration rates during hypoxic hibernation evidently occurs through a reduction in electron-transport chain activity, not through a lowered proton conductance of the mitochondrial inner membrane. The reduced aerobic capacity of frog skeletal muscle during hypoxic hibernation is accompanied by lowered activities of key enzymes of mitochondrial metabolism caused by changes in the intrinsic

El arlequín de limón: una joya en extinción

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Paula Peña

2013-09-01

Full Text Available Estos malignos y pestilentes animales…son detestables por su cuerpo frío, su palidez, esqueleto cartilaginoso, piel desagradable, aspecto feroz, ojos calculadores, olor irritante, voz chillona, moradas miserables y terrible veneno”. Así describió el naturalista sueco Carl Von Linneo en 1758 a los anfibios (Linneo, citado por Wells, 2007: 1. En la actualidad la reputación de sapos y ranas ha mejorado considerablemente, pero todavía existen aquellos que tienen una idea equivocada de estos animales. Lo que estas personas no saben es que las ranas y sapos son elementos de extrema importancia en los ecosistemas naturales, la medicina y la industria turística.

CRAYFISH PREDATION ON TADPOLES : A COMPARISON BETWEEN A NATIVE (AUSTROPOTAMOBIUS PALLIPES AND AN ALIEN SPECIES (PROCAMBARUS CLARKII.

Directory of Open Access Journals (Sweden)

GHERARDI F.

2001-04-01

Full Text Available In the laboratory, the motivation and/or ability to prey on anuran larvae (Bufo bufo, Rana kl. esculenta and R. italica were compared between a native European (Austropotamobius pallipes and an alien North American crayfish species (Procambarus clarkii. Both were skilled predators of tadpoles, adopting a sit-and-wait strategy. However, because P. clarkii displayed lower latency times in the presence of one of the three amphibians (Rana kl. esculenta here tested, the hypothesis is raised that invasive crayfish are more opportunistic predators and possibly faster in switching to different prey than those species they are displacing. From a conservation perspective, these preliminary results further emphasise the importance of studies centred on the invasion-displacement dichotomy.

Rapid Screening for Potential Epitopes Reactive with a Polycolonal Antibody by Solution-Phase H/D Exchange Monitored by FT-ICR Mass Spectrometry

Science.gov (United States)

Zhang, Qian; Noble, Kyle A.; Mao, Yuan; Young, Nicolas L.; Sathe, Shridhar K.; Roux, Kenneth H.; Marshall, Alan G.

2013-07-01

The potential epitopes of a recombinant food allergen protein, cashew Ana o 2, reactive to polyclonal antibodies, were mapped by solution-phase amide backbone H/D exchange (HDX) coupled with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Ana o 2 polyclonal antibodies were purified in the serum from a goat immunized with cashew nut extract. Antibodies were incubated with recombinant Ana o 2 (rAna o 2) to form antigen:polyclonal antibody (Ag:pAb) complexes. Complexed and uncomplexed (free) rAna o 2 were then subjected to HDX-MS analysis. Four regions protected from H/D exchange upon pAb binding are identified as potential epitopes and mapped onto a homologous model.

Population crises and population cycles.

Science.gov (United States)

Russell, C; Russell, W M

2000-01-01

To prevent a population irretrievably depleting its resources, mammals have evolved a behavioural and physiological response to population crisis. When a mammalian population becomes dangerously dense, there is a reversal of behaviour. Co-operation and parental behaviour are replaced by competition, dominance and aggressive violence, leading to high mortality, especially of females and young, and a reduced population. The stress of overpopulation and the resulting violence impairs both the immune and the reproductive systems. Hence epidemics complete the crash of the population, and reproduction is slowed for three or four generations, giving the resources ample time to recover. In some mammal species, crisis and crisis response recur regularly, leading to cycles of population growth and relapse, oscillating about a fixed mean. Population crisis response and population cycles have been equally prominent in the history of human societies. But in man successive advances in food production have made possible growing populations, though with every such advance population soon outgrew resources again. Hence human cycles have been superimposed on a rising curve, producing a saw-tooth graph. Because advances in food production amounted to sudden disturbances in the relations between human populations and their environments, the crisis response in man has failed to avert famine and resource damage. In the large human societies evolved since the coming of settled agriculture and cities, the basic effects of violence, epidemics, famine and resource damage have been mediated by such specifically human disasters as inflation, unemployment, and political tyranny. An account of past crises, periods of relative relief from population pressure, and resulting cycles, is given for a number of regions: China, North Africa and Western Asia, the northern Mediterranean, and north-western Europe. The paper ends with an account of the present world-wide population crisis, and the solution

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.

Probabilistic and possibilistic approach for assessment of radiological risk due to organically bound and tissue free water tritium

International Nuclear Information System (INIS)

Dahiya, Sudhir; Hegde, A.G.; Joshi, M.L.; Verma, P.C.; Kushwaha, H.S.

2006-01-01

This study illustrates use of two approaches namely probabilistic using Monte Carlo simulation (MCS) and possibilistic using fuzzy α-cut (FAC) to estimate the radiological cancer risk to the population from ingestion of organically bound tritium (OBT) and tissue free water tritium (TFWT) from fish consumption from the Rana Pratap Sagar Lake (RPSL), Kota. Using FAC technique, radiological cancer risk rate (year -1 ) at A αl.0 level were 1.15E-08 and 1.50E-09 for OBT and TFWT respectively from fish ingestion pathway. The radiological cancer risk rate (year -1 ) using MCS approach at 50th percentile (median) level is 1.14E-08 and 1.49E-09 for OBT and HTO respectively from ingestion of fresh water fish. (author)

Tratamiento implanto protético de la agenesia del segundo premolar superior: Reporte de un caso clínico

OpenAIRE

Tomaghelli, Emanuel Ricardo; Perdomo Sturniolo, Ivana Lorena

2017-01-01

La agenesia dental es una de las anomalías craneofaciales más comunes en el desarrollo humano. Paciente de género femenino de 22 años de edad que a la inspección ocular se observa la persistencia del diente temporario de la pieza Nº 65, realizando un examen radiográfico en búsqueda del diente permanente retenido o en ubicación ectópica se observa la “agenesia” del mismo. Como plan de tratamiento se optó por la exodoncia atraumática de la pieza temporaria y la colocación inmediata de un impla...

Exotic Amphibians in the Pet Shops of Taiwan

Directory of Open Access Journals (Sweden)

Ping-Chun Lucy Hou

2006-06-01

Full Text Available Pet trade is an important mechanism for introducing alien species. We surveyed a total of 434 pet shops in major cities of Taiwan and found 49 species of alien amphibians belonging to 14 families and 31 genera. Two of the alien species, Rana catesbeiana and Kaloula pulchra, have established in the fields and the other three, Bufo marinus, Xenopus laevis, and Dendrobates auratus, have invasion records in other countries. There were 16 CITES Appendix II species. The most frequently displayed species were the horned frogs, eratophrys spp. And the most abundant species was the American Bullfrog, Rana catesbeiana. We urge the authority of Taiwan establishing regulations on pet trade and enforcing the wildlife conservation law to reduce the risks of alien species invasions.

Distribución y abundancia de Craugastor vulcani: una especie de rana en riesgo de Los Tuxtlas, Veracruz, México Distribution and abundance of Craugastor vulcani: an endangered frog species from Los Tuxtlas, Veracruz, Mexico

Directory of Open Access Journals (Sweden)

Eduardo Pineda

2010-04-01

Full Text Available En México, más de la mitad de las especies de anfibios están amenazadas y de la mayoría no se genera información que permita conocer el estatus en el que se encuentran sus poblaciones. En este trabajo se evaluó la distribución y abundancia de Craugastor vulcani, una rana endémica de la sierra de Los Tuxtlas Veracruz que se encuentra en riesgo de extinción, en función de la transformación de la selva. Para este trabajo, se consultaron bases de datos de registros históricos y se muestrearon 12 sitios que representan ambientes comunes de la región. Se registró un total de 524 individuos, de los cuales el 77% se encontraron en fragmentos de selva, el 20% en remanentes riparios y sólo el 3% en potreros. La mayor abundancia (62% se registró durante la época seca del año. La distribución conocida de C. vulcani está sesgada hacia el norte de la sierra, existe poca información sobre su presencia en la porción sur. La permanencia de la especie en la zona parece depender de los pocos fragmentos de bosque existentes. El aumento en el número, área y conectividad de tales remanentes son algunas de las medidas necesarias para conservar ésta y otras especies amenazadas en la región.More than a half of all amphibian species occurring in Mexico are threatened, and for most of them there is no current information to assess the status of their populations. Craugastor vulcani is an endemic frog from the Los Tuxtlas mountains, Veracruz, and it is classified as an endangered species. We examine the distribution and abundance of C. vulcani as a function of rainforest transformation in Los Tuxtlas. We consulted historical records in databases and sampled 12 sites representing common habitats of the region. We recorded a total of 524 individuals of which 77% were found in rainforest fragments, 20% were collected in riparian remnants and just 3% in cattle pastures. Most individuals (62% were recorded during the dry season. The known distribution

Effect of road deicing salt on the susceptibility of amphibian embryos to infection by water molds.

Science.gov (United States)

Karraker, Nancy E; Ruthig, Gregory R

2009-01-01

Some causative agents of amphibian declines act synergistically to impact individual amphibians and their populations. In particular, pathogenic water molds (aquatic oomycetes) interact with environmental stressors and increase mortality in amphibian embryos. We documented colonization of eggs of three amphibian species, the wood frog (Rana sylvatica), the green frog (Rana clamitans), and the spotted salamander (Ambystoma maculatum), by water molds in the field and examined the interactive effects of road deicing salt and water molds, two known sources of mortality for amphibian embryos, on two species, R. clamitans and A. maculatum in the laboratory. We found that exposure to water molds did not affect embryonic survivorship in either A. maculatum or R. clamitans, regardless of the concentration of road salt to which their eggs were exposed. Road salt decreased survivorship of A. maculatum, but not R. clamitans, and frequency of malformations increased significantly in both species at the highest salinity concentration. The lack of an effect of water molds on survival of embryos and no interaction between road salt and water molds indicates that observations of colonization of these eggs by water molds in the field probably represent a secondary invasion of unfertilized eggs or of embryos that had died of other causes. Given increasing salinization of freshwater habitats on several continents and the global distribution of water molds, our results suggest that some amphibian species may not be susceptible to the combined effects of these factors, permitting amphibian decline researchers to devote their attention to other potential causes.

Specific duplication and dorsoventrally asymmetric expression patterns of Cycloidea-like genes in zygomorphic species of Ranunculaceae.

Science.gov (United States)

Jabbour, Florian; Cossard, Guillaume; Le Guilloux, Martine; Sannier, Julie; Nadot, Sophie; Damerval, Catherine

2014-01-01

Floral bilateral symmetry (zygomorphy) has evolved several times independently in angiosperms from radially symmetrical (actinomorphic) ancestral states. Homologs of the Antirrhinum majus Cycloidea gene (Cyc) have been shown to control floral symmetry in diverse groups in core eudicots. In the basal eudicot family Ranunculaceae, there is a single evolutionary transition from actinomorphy to zygomorphy in the stem lineage of the tribe Delphinieae. We characterized Cyc homologs in 18 genera of Ranunculaceae, including the four genera of Delphinieae, in a sampling that represents the floral morphological diversity of this tribe, and reconstructed the evolutionary history of this gene family in Ranunculaceae. Within each of the two RanaCyL (Ranunculaceae Cycloidea-like) lineages previously identified, an additional duplication possibly predating the emergence of the Delphinieae was found, resulting in up to four gene copies in zygomorphic species. Expression analyses indicate that the RanaCyL paralogs are expressed early in floral buds and that the duration of their expression varies between species and paralog class. At most one RanaCyL paralog was expressed during the late stages of floral development in the actinomorphic species studied whereas all paralogs from the zygomorphic species were expressed, composing a species-specific identity code for perianth organs. The contrasted asymmetric patterns of expression observed in the two zygomorphic species is discussed in relation to their distinct perianth architecture.

Specific duplication and dorsoventrally asymmetric expression patterns of Cycloidea-like genes in zygomorphic species of Ranunculaceae.

Directory of Open Access Journals (Sweden)

Florian Jabbour

Full Text Available Floral bilateral symmetry (zygomorphy has evolved several times independently in angiosperms from radially symmetrical (actinomorphic ancestral states. Homologs of the Antirrhinum majus Cycloidea gene (Cyc have been shown to control floral symmetry in diverse groups in core eudicots. In the basal eudicot family Ranunculaceae, there is a single evolutionary transition from actinomorphy to zygomorphy in the stem lineage of the tribe Delphinieae. We characterized Cyc homologs in 18 genera of Ranunculaceae, including the four genera of Delphinieae, in a sampling that represents the floral morphological diversity of this tribe, and reconstructed the evolutionary history of this gene family in Ranunculaceae. Within each of the two RanaCyL (Ranunculaceae Cycloidea-like lineages previously identified, an additional duplication possibly predating the emergence of the Delphinieae was found, resulting in up to four gene copies in zygomorphic species. Expression analyses indicate that the RanaCyL paralogs are expressed early in floral buds and that the duration of their expression varies between species and paralog class. At most one RanaCyL paralog was expressed during the late stages of floral development in the actinomorphic species studied whereas all paralogs from the zygomorphic species were expressed, composing a species-specific identity code for perianth organs. The contrasted asymmetric patterns of expression observed in the two zygomorphic species is discussed in relation to their distinct perianth architecture.

Response: Discussion of 'Morphotectonic records of neotectonic activity in the vicinity of North Almora Thrust Zone, Central Kumaun Himalaya' by Kothyari et al. (2017), Geomorphology (285), 272-286

Science.gov (United States)

Kothyari, Girish Ch.; Kandregula, Raj Sunil; Luirei, Khayingshing

2018-01-01

Rana and Sharma (2017) dispute our tectonic interpretation mainly on the basis of what they believe (climate?). However, we welcome their comments, as this gives us a chance to highlight the ambiguity inherent in discriminating the climate-tectonic imprints in morphotectonic records that are prevalent in current research. We should note that the paper published by Kothyari et al. (2017) was reviewed by national/international reviewers. We would like to emphasize the fact that the paper does not rule out the role of climate. However, most importantly, it presents significant features and observations that collection/assemblage points toward the dominant role of tectonics in their shaping, and not solely climate, as postulated by Rana and Sharma (2017). The objective of this paper is to identify tectonic signatures (geomorphology) in a monsoon - dominated, tectonically active terrain like the North Almora Thrust (NAT). These faults are marked by previous workers based on field evidence such as folding and faulting of lithological units; presence of slickensides parallel to the fault; offset of NAT owing to a transverse fault; and offset of drainage, drainage basin analysis, strath terraces, fluviolacustrine terraces, development of scarp, narrow river course, and deeply incised valleys. However, we disagree with the comments raised by Rana and Sharma (2017), because they are highly skewed toward the climate school of thought, and did not perceive the setting as a collection of landforms. Instead, they attempted to view them in isolation. Because these comments are important, we will try to further our research incorporating issues related to isolation of climate and tectonics imprints in the immediate future. We would like to thank Rana and Sharma (2017) for raising some basic questions on our work as this gave us an excellent opportunity to summarize and present the dominance of various processes and related landforms as earlier reported by Kothyari et al. (2017). A

Nucleotide diversity and phylogenetic relationships among ...

Indian Academy of Sciences (India)

2017-03-03

Mar 3, 2017 ... 2Department of Botany, D. S. B. Campus, Kumaun University, Nainital 263 001, India ... Rana T. S. 2017 Nucleotide diversity and phylogenetic relationships ... Anderson and Park 1989). ..... Edgewood Press, Edgewood, USA.

A skeletochronological study of growth, longevity, and age at sexual ...

Indian Academy of Sciences (India)

Unknown

nearest mm, body weight, and reproductive status were recorded. Before release ..... analysis to ascertain whether bone resorption might have completely removed one or .... distribution and longevity in the Ramsey Canyon leopard frog, Rana ...

Nematodes of amphibians from Java, Indonesia, with a description of new species, Meteterakis wonosoboensis n. sp. (Nematoda : Heterakoidea).

Science.gov (United States)

Purwaningsih, Endang; Dewi, Kartika; Hasegawa, Hideo

2015-06-24

During a survey on the parasites of amphibians of Indonesia, toads (30 Bufo melanostictus) and 246 frogs (213 Fejervarya cancrivora, 11 F. limnocharis, 22 Rana macrodon from West Java and 68 F. cancrivora from Central Java) were examined for parasitic nematodes. Three species of nematodes were found and described, i.e. Meteterakis wonosoboensis n. sp. from Fejervaria cancrivora; Meteterakis japonica from Bufo melanostictus, F. cancrivora and F. limnocharis; and Chabaudus sp. from F. cancrivora, F. limnocharis and Rana macrodon. Meteterakis wonosoboensis n. sp. is distinguished from other species of the genus by the length and shape of spicules, the number of caudal papillae, the presence of gubernaculum in male and the presence of vulval flap in female. Bufo melanostictus and Java are recorded as new host and locality for M. japonica, respectively.

Amphibians of the “Cilento e Vallo di Diano” National Park (Campania, Southern Italy: updated check list, distribution and conservation notes

Directory of Open Access Journals (Sweden)

Antonio Romano

2010-12-01

Full Text Available In this study, we present the results of our field and bibliographic survey on the amphibians of the “Cilento and Vallo di Diano” National Park (Southern Italy. Two hundred and thirty three spawning sites (167 original and 66 derived from literature, and 11 amphibian species were found. Reproductive activity was recorded for Salamandra salamandra, Salamandrina terdigitata, Triturus carnifex, Lissotriton italicus, Bufo bufo, Hyla intermedia, Rana italica, Rana dalmatina and Pelophylax synkl. hispanica. The distribution record of many species is widely improved with respect to bibliographic data. Our results also suggested that preservation and restoration of small aquatic sites, in particular of the artificial ones, such as stony wells and drinking-troughs, are fundamental for an appropriate conservation management of amphibians in the “Cilento and Vallo di Diano” National Park.

Blood parasites of amphibians from Sichuan Province, People's Republic of China.

Science.gov (United States)

Werner, J K

1993-06-01

Two hundred forty-six amphibians from Sichuan Province, People's Republic of China, were examined for blood parasites between April and June 1990. Six trypanosome species were found, 2 of which were not identified because of poor material. Trypanosoma rotatorium (sensu Mayer, 1843) was found in Rana limnocharis and Rana nigromaculata. Trypanosoma chattoni and a T. rotatorium-like species were found in Bufo gargarizans. A sphaeromastigote similar to Trypanosoma tsunezomiyatai was seen in R. limnocharis. The relationship of this parasite to T. chattoni is unclear. Dactylosoma ranarum, Lankesterella minima, and Aegyptianella bacterifera were identified in ranids. Frog erythrocytic virus (FEV) was found in 2 ranids and a bufonid. Differences in shape of FEV and its assumed effect on the host-cell nucleus suggest that different kinds of viruses may be involved.

Farm Population of the United States: 1972. Current Population Reports: Farm Population.

Science.gov (United States)

Bureau of the Census (DOC), Suitland, MD. Population Div.

Based on data derived from the Current Population Survey of the Bureau of Census, this statistical report presents demographic and labor force characteristics of the U.S. farm population and comparisons of the farm and nonfarm populations. Tabular data are presented as follows: (1) U.S. Population, Total and Farm: April 1960 to 1972; (2) Persons…

Farm Population of the United States: 1974. Current Population Reports, Farm Population.

Science.gov (United States)

Banks, Vera J.; And Others

Based on data derived primarily from the Current Population Survey of the Bureau of the Census, this statistical report presents demographic and labor force characteristics of the U.S. farm population and a comparison of selected characteristics of the farm and nonfarm population. Tabular data are presented as follows: (1) Population of the U.S.,…

Farm Population of the United States: 1971. Current Population Reports: Farm Population.

Science.gov (United States)

Bureau of the Census (DOC), Suitland, MD. Population Div.

Based on data derived from the Current Population Survey of the Bureau of the Census, this statistical report presents demographic and labor force characteristics of the U.S. farm population and comparisons of the farm and nonfarm populations. Tabular data are presented as follows: (1) U.S. Population, Total and Farm: April 1960 and 1971; (2)…

Impact assessment on the human exposure to environmental radiation

International Nuclear Information System (INIS)

Kim, Y.J.; Lee, K.S.; Kim, J.B.; Chun, K.J.; Kim, S.R.; Chung, K.H.

1983-01-01

1. The Terrestrial Ecosystem in the Vicinity of Kori Nuclear Power Plant. In order to evaluate the effects of radiation or radionuclides released from the nuclear power plants on human population, field surveys on the terrestrial ecosystem such as the fauna and flora in the vicinity within 15 km from the Kori nuclear power plant were carried out. 2. Level of radionuclides, Metabolism and Chromosome Aberration. The present study was undertaken with the purpose for evaluating 1) the level of Sr-90 in the Korean vertebra, 2) the metabolism of Sr-90 in the rats, 3) the levels of Sr-90 and Cs-137 in the pine needles (Pinus densiflora), 4) the level of Sr-90 in the frogs (Rana nigromaculata) and 5) the radiation effects by internal Sr-90 on the bone marrow. (Author)

Population control II: The population establishment today.

Science.gov (United States)

Hartmann, B

1997-01-01

Although population assistance represents a relatively small share of official development assistance, it influences many other aspects of development planning. The organizations that comprise the population establishment have a common purpose--the reduction of population growth in the Third World--but they are not homogeneous and sometimes have conflicting goals and strategies. National governments, multilateral agencies, nongovernmental organizations, foundations, academic centers, and pressure groups all contribute to creating and sustaining what has become a virtual population control industry. Through scholarships, travel grants, awards, and favorable publicity, Third World elites have been encouraged to join the population establishment. The World Bank, the U.S. Agency for International Development, and the U.N. Fund for Population Activities have pursued explicit strategies for pressuring Third World governments to design and implement population policies, most recently in Africa.

The high cost of cheap clothes | IDRC - International Development ...

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

2017-05-31

May 31, 2017 ... The collapse of a garment factory in Dhaka, Bangladesh, on April 24, 2013, ... the Rana Plaza garment factory killed more than 1,000 people in Bangladesh, ... Does labour-intensive manufacturing promote economic mobility?

Inventory of the pool frog, newt and gulyxne in Forsmark 2012

International Nuclear Information System (INIS)

Collinder, Per

2013-01-01

On assignment from the Swedish Nuclear Fuel and Waste Management Co (SKB), Ekologigruppen AB carried out inventories of species populations during the summer of 2012. Species included in the study are described in three separate chapters of this report. The three species were pool frog Rana lessonae, great crested newt Triturus cristatus, and fen orchid Liparis loeselii. SKB will follow up the development of the local populations. Inventory of pool frogs are already a follow-up on a study carried out in 2011. Concern for these species is due to their protection within the EU system of species and habitat protection. Construction of the planned depository for used nuclear fuel will involve redirection of groundwater, which could potentially drain these wetlands. The three species pool frog, great crested newt and fen orchid are inventoried by well-documented procedures, which will allow repletion of the study at the same locals and according to the same methods during consequent years. The inventories are not complete in the sense that they would give number of individuals in a local population. Rather, the result should be regarded as an index for comparison and monitoring

Inventory of the pool frog, newt and gulyxne in Forsmark 2012; Inventering av goelgroda, stoerre vattensalamander och gulyxne i Forsmark 2012

Energy Technology Data Exchange (ETDEWEB)

Collinder, Per [Ekologigruppen AB, Stockholm (Sweden)

2013-01-15

On assignment from the Swedish Nuclear Fuel and Waste Management Co (SKB), Ekologigruppen AB carried out inventories of species populations during the summer of 2012. Species included in the study are described in three separate chapters of this report. The three species were pool frog Rana lessonae, great crested newt Triturus cristatus, and fen orchid Liparis loeselii. SKB will follow up the development of the local populations. Inventory of pool frogs are already a follow-up on a study carried out in 2011. Concern for these species is due to their protection within the EU system of species and habitat protection. Construction of the planned depository for used nuclear fuel will involve redirection of groundwater, which could potentially drain these wetlands. The three species pool frog, great crested newt and fen orchid are inventoried by well-documented procedures, which will allow repletion of the study at the same locals and according to the same methods during consequent years. The inventories are not complete in the sense that they would give number of individuals in a local population. Rather, the result should be regarded as an index for comparison and monitoring.

Using occupancy models to understand the distribution of an amphibian pathogen, Batrachochytrium dendrobatidis

Science.gov (United States)

Adams, Michael J.; Chelgren, Nathan; Reinitz, David M.; Cole, Rebecca A.; Rachowicz, L.J.; Galvan, Stephanie; Mccreary, Brome; Pearl, Christopher A.; Bailey, Larissa L.; Bettaso, Jamie B.; Bull, Evelyn L.; Leu, Matthias

2010-01-01

Batrachochytrium dendrobatidis is a fungal pathogen that is receiving attention around the world for its role in amphibian declines. Study of its occurrence patterns is hampered by false negatives: the failure to detect the pathogen when it is present. Occupancy models are a useful but currently underutilized tool for analyzing detection data when the probability of detecting a species is <1. We use occupancy models to evaluate hypotheses concerning the occurrence and prevalence of B. dendrobatidis and discuss how this application differs from a conventional occupancy approach. We found that the probability of detecting the pathogen, conditional on presence of the pathogen in the anuran population, was related to amphibian development stage, day of the year, elevation, and human activities. Batrachochytrium dendrobatidis was found throughout our study area but was only estimated to occur in 53.4% of 78 populations of native amphibians and 66.4% of 40 populations of nonnative Rana catesbeiana tested. We found little evidence to support any spatial hypotheses concerning the probability that the pathogen occurs in a population, but did find evidence of some taxonomic variation. We discuss the interpretation of occupancy model parameters, when, unlike a conventional occupancy application, the number of potential samples or observations is finite.

Nucleotide diversity and phylogenetic relationships among ...

Indian Academy of Sciences (India)

Navya

1CSIR-National Botanical Research Institute, Rana Pratap Marg, Lucknow ... used to characterize and identify the cultivars; however, it is often difficult and even .... complete deletion of the missing/gap sites from all the sequences (table 2).

Acute and chronic effects of organophosphate pesticides (Basudin ...

African Journals Online (AJOL)

SERVER

2007-07-04

Jul 4, 2007 ... been shown to have negative effects on amphibian deve- lopment. ... (1933). The results were expressed as a percentage of the wet weight of tissue. .... life stages of the southern leopard frog (Rana sphenocephala). Arch.

A natriferic principle other than arginine-vasotocin in the frog neuro hypophysis (1961)

International Nuclear Information System (INIS)

Morel, F.; Maetz, J.

1961-01-01

In the neurohypophysis of Rana esculenta there exists, in addition to vasotocin, an unknown active principle which accounts for approximately half of the total natriferic activity of the gland. This principle is not found in chickens. (authors) [fr

Allozyme comparison of three Trypanosoma species (Kinetoplastida: Trypanosomatidae) of toads and frogs by starch-gel electrophoresis.

Science.gov (United States)

Martin, D S; Desser, S S; Hong, H

1992-04-01

Six metabolic enzymes, glucose-6-phosphate dehydrogenase, glucosephosphate isomerase, isocitrate dehydrogenase, malate dehydrogenase, phosphoglucomutase, and purine nucleoside phosphorylase, from clonal isolates of 3 presumptive species of Trypanosoma (T. fallisi, T. ranarum, and T. rotatorium) from 3 anuran hosts (Bufo americanus, Rana clamitans, and Rana catesbeiana) were compared using starch-gel electrophoresis. Although bands were shared among the different zymodemes of isolates of the same host genus, low genetic polymorphism of the enzyme loci was observed with few apparent shared bands between samples isolated from frogs and toads. A distance value calculated between toad and frog trypanosome isolates suggests the likelihood of long-time separation of species. Cluster analysis based on overall similarity distinguished the trypanosomes of toads and frogs as separate taxa, suggesting that host specificity and observed morphological differences are consistent with heritable allozyme differences.

Farm Population of the United States: 1976. Current Population Reports: Farm Population.

Science.gov (United States)

Banks, Vera J.; And Others

Prepared cooperatively by the Bureau of the Census and the Economic Research Service of the U.S. DeparLment of Agriculture, this document presents narrative and tabular data on: demographic and social characteristics of the farm population; economic characteristics of the farm population; revision of farm population processing procedures; and…

Fulltext PDF

Indian Academy of Sciences (India)

Prakash

the background scattering due to slow tissue degradation or ... aorta isolated from Rana tigrina were tested for their ability to reduce ferricyanide, methylene blue, and 2,6- .... Merker M P, Bongrad R D, Linehan J H, Okamoto Y, Vyprachticky.

Environmental Assessment, Change in C-17 Flight Training Operations at Grant County International Airport, Washington by Joint Base Lewis-McChord

Science.gov (United States)

2011-10-01

young in the ocean. Resident and juvenile bull trout prey on invertebrates and small fish. Adult migratory bull trout primarily eat fish. Resident...Federal Status Amphibians 1 Northern leopard frog Rana pipiens Endangered None Birds 2 Bald eagle Haliaeetus

Correlates of virulence in a frog-killing fungal pathogen: evidence from a California amphibian decline.

Science.gov (United States)

Piovia-Scott, Jonah; Pope, Karen; Worth, S Joy; Rosenblum, Erica Bree; Poorten, Thomas; Refsnider, Jeanine; Rollins-Smith, Louise A; Reinert, Laura K; Wells, Heather L; Rejmanek, Dan; Lawler, Sharon; Foley, Janet

2015-07-01

The fungal pathogen Batrachochytrium dendrobatidis (Bd) has caused declines and extinctions in amphibians worldwide, and there is increasing evidence that some strains of this pathogen are more virulent than others. While a number of putative virulence factors have been identified, few studies link these factors to specific epizootic events. We documented a dramatic decline in juvenile frogs in a Bd-infected population of Cascades frogs (Rana cascadae) in the mountains of northern California and used a laboratory experiment to show that Bd isolated in the midst of this decline induced higher mortality than Bd isolated from a more stable population of the same species of frog. This highly virulent Bd isolate was more toxic to immune cells and attained higher density in liquid culture than comparable isolates. Genomic analyses revealed that this isolate is nested within the global panzootic lineage and exhibited unusual genomic patterns, including increased copy numbers of many chromosomal segments. This study integrates data from multiple sources to suggest specific phenotypic and genomic characteristics of the pathogen that may be linked to disease-related declines.

Population Growth and National Population Policy of India

Science.gov (United States)

Thukral, A. K.; Singh, B. P.

2008-01-01

The population growth in India may overtake China by the year 2030. The National Population Policy of India targets population stabilization in India by the year 2045. The present paper carries out objective analysis of the population growth in India in terms of change in specific growth. At the present rate of specific growth rate decline, the population by the end of the century will be 2.49 billion. For the population to achieve zero growth by the year 2045, a decline in specific growth rate will have to be achieved at the rate of 0.000428 per year.

Decay of Hoyle state

Indian Academy of Sciences (India)

2014-11-02

Nov 2, 2014 ... T K RANA, C BHATTACHARYA, S KUNDU, ... of various direct 3α decay mechanisms of the Hoyle state. ... Pramana – J. Phys., Vol. ... FMD predicts a compact triangle shape and LEFT predicts a bent arm chain structure,.

Ammoxidation of 2-methyl pyrazine on supported ammonium salt of ...

Indian Academy of Sciences (India)

Investigations using 31P MAS NMR spectroscopy of samples revealed that. Keggin ion existed ..... De-convoluted 31P MAS NMR data of AMPA on different supports. Loading (wt%) ..... Rana S, Mallick S and Parida K M 2012 J. Porous. Mater.

Mona F1: New pepper (Capsicum annuum L. hybrid in the Centre for Vegetable Crops

Directory of Open Access Journals (Sweden)

Cvikić Dejan

2007-01-01

Full Text Available The planted area various ways of pepper consumption (fresh or processed, make pepper one of the most important cultivars in vegetable breeding. In our country, up until now, the producers have usually grown varieties and domestic populations of pepper, while in more developed countries the usage of F1 hybrids is much more popular. The first pepper hybrids have been created in the Centre for Vegetable Crops by crossing new lines with male sterility gene ms-3 and selected genotypes from pepper collection. Created hybrids have higher yield, quality fruits and early ripening. This paper is the result of comparative trial in controlled conditions. Pepper varieties Župska rana, Zlatna medalja, Palanačka kapija and Duga bela, as well as new hybrid Mona F1 were the research matherial in order to observe the most important pepper traits.

Farm Population of the United States: 1977. Current Population Reports: Farm Population.

Science.gov (United States)

Banks, Vera J.; DeAre, Diana

The farm population has declined fairly steadily for more than half a century. By 1970 the proportion of the U.S. population residing on farms had fallen to about 5 per cent, and by 1977 had dropped to 3.6 per cent. About 1.4 per cent of the farm population was of Spanish origin (represented for the first time in this year's report), as compared…

Njv Magazine 3 final

African Journals Online (AJOL)

En-Joy

diseases, including neoplasia (Done, 1996), viral (Buffetaut and Upton, 1997;. Jacopson, 1989), bacterial (Foggin, 1987) mycotic (Jacopson, 1989) and parasitic .... LECLAIR Jr., R and CASTANET, J. A. (1987): Skeletochronological assessment of age and growth in the frog Rana pipiens Schreber. (Amphibia, Anura) from.

Journal of Chemical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

Triethylammonium salt of dimethyl diphenyldithiophosphates: Single crystal X-ray and DFT analysis. SANDEEP KUMAR RUCHI KHAJURIA MANDEEP KOUR RAKESH KUMAR LOVE KARAN RANA GEETA HUNDAL VIVEK K GUPTA RAJNI KANT SUSHIL K PANDEY. Regular Article Volume 128 Issue 6 June 2016 pp ...

Characterization of pars intermedia connections in amphibians by biocytin tract tracing and immunofluorescence aided by confocal microscopy

NARCIS (Netherlands)

Jansen, K; Fabro, C; Artero, C; Feuilloley, M; Vaudry, H; Fasolo, A; Franzoni, MF

Biocytin, recently introduced in neuroanatomical studies, was used as a retrograde tract tracer in combination with immunofluorescence in order to analyse the neurochemical characters of some central neuronal projections to the pars intermedia in two amphibian species, the anuran Rana esculenta and

Sadhana | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Sadhana. DWAIPAYAN SARKAR. Articles written in Sadhana. Volume 42 Issue 4 April 2017 pp 533-541. Immersed boundary simulation of flow through arterial junctions · DWAIPAYAN SARKAR NISHANT UPADHYAY SOMNATH ROY SUBHAS CHANDRA RANA · More Details Abstract Fulltext PDF.

Browse Title Index

African Journals Online (AJOL)

Items 251 - 300 of 462 ... Manar Obada, Ashraf El-Fert, Mohamed S. Hashim, Mones Obada, ... M Essawi, H Nasr, I Mazen, K Gaafar, K Amr, M Hafez, Y Gad ... Farida El Baza, Heba Ahmed AlShahawi, Sally Zahra, Rana Ahmed AbdelHakim.

Memorias de un protagonista

Directory of Open Access Journals (Sweden)

Martha Cecilia Herrera C.

1987-10-01

Full Text Available Facultades de educación y Escuela Normal Superior: Su historia y aporte científico, humanístico y educativo. José Francisco Socarrás. Ediciones La Rana y el Aguila, Tunja, 1987, 169 págs.

DIAGNOSTIC CHARACTERS OF TOMOPTERNA AND RANA ...

African Journals Online (AJOL)

five-toed stage, of a spur on the hind foot, giving a six-toed appearance when the spur first appears. This feature ... In the main key, besides the spur on the foot, tail and spiracle characters were used, the former with the .... and is generally pale ... ' (p. 96) and 'They reach a maximum of 70 mm, and are flat, heavy tadpoles ..•.

Population and population policy in Pakistan.

Science.gov (United States)

Mauldin, W P

1963-02-01

Pakistan is a divided country with different religious groups represented. Since independence in 1941, the Muslim population has increased more rapidly than the Hindu population, the West Pakistan population more rapidly and steadily than the East Pakistan population. In the late 1950s the Pakistan government initiated a family planning program. The program has trained medical and paramedical personnel in family planning, added family planning services to existing medical centers, planned for a National Research Institute of Family Planning, employed mobile units to reach outlying areas, conducted limited clinical studies on some contraceptives, and used mass media advertising. Only India and Japan are doing more with government-sponsored family planning. A weak organizational structure and an inadequate number of trained personnel are the main weakness of the program. It is too early to assess the success of the program. A 10-point reduction in annual birth rates will be considered successful.

Proceedings – Mathematical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Proceedings – Mathematical Sciences; Forthcoming articles. Forthcoming articles. Proceedings – Mathematical Sciences. PMSC-D-14-00136. Combinatorics of tenth order mock theta functions. J K SAREEN M RANA. Abstract. In this paper we are providing the combinatorial interpretations of two tenth ...

Journal of Chemical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

Triethylammonium salt of dimethyl diphenyldithiophosphates: Single crystal X-ray and DFT analysis · SANDEEP KUMAR RUCHI KHAJURIA MANDEEP KOUR RAKESH KUMAR LOVE KARAN RANA GEETA HUNDAL VIVEK K GUPTA RAJNI KANT SUSHIL K PANDEY · More Details Abstract Fulltext PDF. The present work ...

Epidemiology Characteristics of Constipation for General Population, Pediatric Population, and Elderly Population in China

Directory of Open Access Journals (Sweden)

Huikuan Chu

2014-01-01

Full Text Available Objective. To acquire more data about the epidemiologic characteristics of constipation in different kinds of populations in China. Methods. Using “constipation” and “China” as search terms; relevant papers were searched from January 1995 to April 2014. Data on prevalence, gender, diagnostic criteria, geographical area, educational class, age, race, and physician visit results were extracted and analyzed. Results. 36 trials were included. Prevalence rates of constipation in elderly population (18.1% and pediatric population (18.8% were significantly higher than that in general population (8.2%. Prevalence of constipation defined by non-Rome criteria was higher than that by Rome criteria in general population. Prevalence rates of constipation were different for different geographical area. People with less education were predisposed to constipation. In pediatric population, prevalence of constipation was the lowest in children aged 2–6 years. Prevalence of constipation in ethnic minorities was higher than that in Han people. People with constipation were predisposed to FD, haemorrhoid, and GERD. Only 22.2% patients seek medical advice in general population. Conclusions. In China, prevalence of constipation was lower compared with most of other countries. The factors including female gender, diagnostic criteria, geographical area, age, educational class, and race seemed to have major effects on prevalence of constipation.

Imaginary populations

Directory of Open Access Journals (Sweden)

A. Martínez–Abraín

2010-01-01

Full Text Available A few years ago, Camus & Lima (2002 wrote an essay to stimulate ecologists to think about how we define and use a fundamental concept in ecology: the population. They concluded, concurring with Berryman (2002, that a population is "a group of individuals of the same species that live together in an area of sufficient size to permit normal dispersal and/or migration behaviour and in which population changes are largely the results of birth and death processes". They pointed out that ecologists often forget "to acknowledge that many study units are neither natural nor even units in terms of constituting a population system", and hence claimed that we "require much more accuracy than in past decades in order to be more effective to characterize populations and predict their behaviour". They stated that this is especially necessary "in disciplines such as conservation biology or resource pest management, to avoid reaching wrong conclusions or making inappropriate decisions". As a population ecologist and conservation biologist I totally agree with these authors and, like them, I be¬lieve that greater precision and care is needed in the use and definition of ecological terms. The point I wish to stress here is that we ecologists tend to forget that when we use statistical tools to infer results from our sample to a population we work with what statisticians term "imaginary", "hypothetical" or "potential" popula¬tions. As Zar (1999 states, if our sample data consist of 40 measurements of growth rate in guinea pigs "the population about which conclusions might be drawn is the growth rates of all the guinea pigs that conceivably might have been administered the same food supplement under identical conditions". Such a population does not really exist, and hence it is considered a hypothetical or imaginary population. Compare that definition with the population concept that would be in our minds when performing such measurements. We would probably

a Morphometric Analysis of HYLARANA SIGNATA Group (previously Known as RANA SIGNATA and RANA PICTURATA) of Malaysia

Science.gov (United States)

Zainudin, Ramlah; Sazali, Siti Nurlydia

A study on morphometrical variations of Malaysian Hylarana signata group was conducted to reveal the morphological relationships within the species group. Twenty-seven morphological characters from 18 individuals of H. signata and H. picturata were measured and recorded. The numerical data were analysed using Discriminant Function Analysis in SPSS program version 16.0 and UPGMA Cluster Analysis in Minitab program version 14.0. The results show the complexity clustering between the examined species that might be due to ancient polymorphism of the lineages or cryptic species within the group. Hence, further study should include more representatives in order to fully elucidate the morphological relationships of H. signata group.

Effects of road de-icing salt (NaCl) on larval wood frogs (Rana sylvatica)

International Nuclear Information System (INIS)

Sanzo, Domenico; Hecnar, Stephen J.

2006-01-01

Vast networks of roads cover the earth and have numerous environmental effects including pollution. A major component of road runoff in northern countries is salt (mostly NaCl) used as a winter de-icing agent, but few studies of effects of road salts on aquatic organisms exist. Amphibians require aquatic habitats and chemical pollution is implicated as a major factor in global population declines. We exposed wood frog tadpoles to NaCl. Tests revealed 96-h LC50 values of 2636 and 5109 mg/l and tadpoles experienced reduced activity, weight, and displayed physical abnormalities. A 90 d chronic experiment revealed significantly lower survivorship, decreased time to metamorphosis, reduced weight and activity, and increased physical abnormalities with increasing salt concentration (0.00, 0.39, 77.50, 1030.00 mg/l). Road salts had toxic effects on larvae at environmentally realistic concentrations with potentially far-ranging ecological impacts. More studies on the effects of road salts are warranted. - Road salts have toxic effects on amphibians at environmentally realistic concentrations

Effects of road de-icing salt (NaCl) on larval wood frogs (Rana sylvatica)

Energy Technology Data Exchange (ETDEWEB)

Sanzo, Domenico [Department of Biology, Lakehead University, 955 Oliver Road, Thunder Bay, ON, P7B 5E1 (Canada); Hecnar, Stephen J. [Department of Biology, Lakehead University, 955 Oliver Road, Thunder Bay, ON, P7B 5E1 (Canada)]. E-mail: stephen.hecnar@lakeheadu.ca

2006-03-15

Vast networks of roads cover the earth and have numerous environmental effects including pollution. A major component of road runoff in northern countries is salt (mostly NaCl) used as a winter de-icing agent, but few studies of effects of road salts on aquatic organisms exist. Amphibians require aquatic habitats and chemical pollution is implicated as a major factor in global population declines. We exposed wood frog tadpoles to NaCl. Tests revealed 96-h LC50 values of 2636 and 5109 mg/l and tadpoles experienced reduced activity, weight, and displayed physical abnormalities. A 90 d chronic experiment revealed significantly lower survivorship, decreased time to metamorphosis, reduced weight and activity, and increased physical abnormalities with increasing salt concentration (0.00, 0.39, 77.50, 1030.00 mg/l). Road salts had toxic effects on larvae at environmentally realistic concentrations with potentially far-ranging ecological impacts. More studies on the effects of road salts are warranted. - Road salts have toxic effects on amphibians at environmentally realistic concentrations.

Non-native species impacts on pond occupancy by an anuran

Science.gov (United States)

Adams, Michael J.; Pearl, Christopher A.; Galvan, Stephanie; McCreary, Brome

2011-01-01

Non-native fish and bullfrogs (Lithobates catesbeianus; Rana catesbeiana) are frequently cited as factors contributing to the decline of ranid frogs in the western United States (Bradford 2005). This hypothesis is supported by studies showing competition with or predation by these introduced species (Kupferberg 1997, Kiesecker and Blaustein 1998, Lawler et al. 1999, Knapp et al. 2001) and studies suggesting a deficit of native frogs at sites occupied by bullfrogs or game fish (Hammerson 1982, Schwalbe and Rosen 1988, Fisher and Shaffer 1996, Adams 1999). Conversely, other studies failed to find a negative association between native ranids and bullfrogs and point out that presence of non-native species correlates with habitat alterations that could also contribute to declines of native species (Hayes and Jennings 1986; Adams 1999, 2000; Pearl et al. 2005). A criticism of these studies is that they may not detect an effect of non-native species if the process of displacement is at an early stage. We are not aware of any studies that have monitored a set of native frog populations to determine if non-native species predict population losses. Our objective was to study site occupancy trends in relation to non-native species for northern red-legged frogs (Rana aurora) on federal lands in the southern Willamette Valley, Oregon. We conducted a 5-yr monitoring study to answer the following questions about the status and trends of the northern red-legged frog: 1) What is the rate of local extinction (how often is a site that is occupied in year t unoccupied in year t+1) and what factors predict variation in local extinction? and 2) What is the rate of colonization (how often is a site that is unoccupied in year t occupied in year t+1) and what factors predict variation in colonization? The factors we hypothesized for local extinction were: 1) bullfrog presence, 2) bullfrogs mediated by wetland vegetation, 3) non-native fish (Centrarchidae), 4) non-native fish mediated by

Nigerian Journal of Surgery - Vol 22, No 2 (2016)

African Journals Online (AJOL)

Assessment of the survival of dental implants in irradiated jaws following treatment of oral cancer: A retrospective study · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Meenakshi Chauhan Rana, Swati Solanki, Sudarshan C Pujari, Eisha Shaw, Swati Sharma, ...

One step forward or more window-dressing? A legal analysis of the recent CSR Initiatives in the Garment Industry in Bangladesh

NARCIS (Netherlands)

ter Haar, B.; Keune, M.

2014-01-01

The Bangladesh ready-made garment industry has recently been affected by a number of terrible accidents, with the collapse of the Rana Plaza on 24 April 2013 as the deadliest garment-factory accident ever known. Under the pressure of renewed attention to the role and responsibilities of

Toxicity of road salt to Nova Scotia amphibians.

Science.gov (United States)

Collins, Sara J; Russell, Ronald W

2009-01-01

The deposition of chemical pollutants into roadside wetlands from runoff is a current environmental concern. In northern latitudes, a major pollutant in runoff water is salt (NaCl), used as de-icing agents. In this study, 26 roadside ponds were surveyed for amphibian species richness and chloride concentration. Acute toxicity tests (LC(50)) were performed on five locally common amphibian species using a range of environmentally significant NaCl concentrations. Field surveys indicated that spotted salamanders (Ambystoma maculatum) and wood frogs (Rana sylvatica) did not occupy high chloride ponds. American toads (Bufo americanus) showed no pond preference based on chloride concentration. Acute toxicity tests showed spotted salamanders and wood frogs were most sensitive to chloride, and American toads were the least. Spring peepers (Pseudacris crucifer) and green frogs (Rana clamitans) showed intermediate sensitivities. We concluded that chloride concentrations in ponds due to application of de-icing salts, influenced community structure by excluding salt intolerant species.

Identifying behavioural determinants for interventions to increase handwashing practices among primary school children in rural Burundi and urban Zimbabwe.

Science.gov (United States)

Seimetz, Elisabeth; Slekiene, Jurgita; Friedrich, Max N D; Mosler, Hans-Joachim

2017-07-14

This article presents the development of a school handwashing programme in two different sub-Saharan countries that applies the RANAS (risk, attitudes, norms, ability, and self-regulation) systematic approach to behaviour change. Interviews were conducted with 669 children enrolled in 20 primary schools in Burundi and 524 children in 20 primary schools in Zimbabwe. Regression analyses were used to assess the influence of the RANAS behavioural determinants on reported handwashing frequencies. The results revealed that, in both countries, a programme targeting social norms and self-efficacy would be most effective. In Burundi, raising the children's perceived severity of the consequences of contracting diarrhoea, and in Zimbabwe, increasing the children's health knowledge should be part of the programme. The school handwashing programme should create awareness of the benefits of handwashing through educational activities, raise the children's ability and confidence in washing hands at school through infrastructural improvements, and highlight the normality of washing hands at school through events and poster creation.

Vertebrate hosts and phylogenetic relationships of amphibian trypanosomes from a potential invertebrate vector, Culex territans Walker (Diptera: Culicidae).

Science.gov (United States)

Bartlett-Healy, Kristen; Crans, Wayne; Gaugler, Randy

2009-04-01

The blood meals of field-collected female Culex territans (Diptera: Culicidae) were concurrently assayed for the presence of trypanosomes and for vertebrate host identification. We amplified vertebrate DNA in 42 of 119 females and made positive identification to the host species level in 29 of those samples. Of the 119 field-collected Cx. territans females, 24 were infected with trypanosomes. Phylogenetic analysis placed the trypanosomes in the amphibian portion of the aquatic clade of the Trypanosomatidae. These trypanosomes were isolated from Cx. territans females that had fed on the frog species Rana clamitans, R. catesbeiana, R. virgatipes, and Rana spp. Results support a potential new lineage of dipteran-transmitted amphibian trypanosomes may occur within the aquatic clade. The frequency in which female Cx. territans acquire trypanosomes, through diverse feeding habits, indicates a new relationship between amphibian trypanosomes and mosquitoes that has not been examined previously. Combining Trypanosoma species, invertebrate, and vertebrate hosts to existing phylogenies can elucidate trypanosome and host relationships.

Understanding Population.

Science.gov (United States)

Mothner, Ira

Activities and concerns of Ford Foundation supported population research and training centers are described in this report. The centers are concerned with population growth, consequences of growth for human welfare, forces that determine family planning, interrelations among population variables, economics of contraceptive distribution, and…

Electrofishing method improves evaluation of amphibian larvae abundance: a case of "beaver rivers".

Science.gov (United States)

Dgebuadze, Yury Y; Bashinskiy, Ivan V

2017-07-01

There are many locations in Russia where Eurasian beaver (Castor fiber) populations have been restored. As a keystone species, beavers provide wide-ranging direct and indirect impacts on aquatic ecosystems. In particular, beaver-created ponds are sites for spawning and nursery places for tadpoles of the brown frogs (genus Rana). Because of such impacts, study techniques for assessing aquatic organism abundance are being developed. We compared two methods for estimating tadpole abundance: traditional catches by dipnet and electrofishing. Our results show that the dipnet catch data for the shallower ponds with larger water surface area were five times lower than that obtained by electrofishing. Therefore, we conclude that dipnet catches are not suitable for comparing the relative abundance of tadpoles in the two beaver ponds that were studied. © 2016 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

Density Estimation in Several Populations With Uncertain Population Membership

KAUST Repository

Ma, Yanyuan

2011-09-01

We devise methods to estimate probability density functions of several populations using observations with uncertain population membership, meaning from which population an observation comes is unknown. The probability of an observation being sampled from any given population can be calculated. We develop general estimation procedures and bandwidth selection methods for our setting. We establish large-sample properties and study finite-sample performance using simulation studies. We illustrate our methods with data from a nutrition study.

Thermoregulation in the hippopotamus on land

African Journals Online (AJOL)

1986-11-28

Nov 28, 1986 ... tadpoles (Anura: Bufonidae). Zool. Afr. 8:153-156. CHANNING, A. 1976. Rana johnstoni inyangae tadpoles from Rhodesia. Amoldia Rhod. 8: 1-4. CHANNING, A. 1978. A new bufonid genus (Amphibia: Anura) from Rhodesia. Herpetologica 34: 394-397. FROST, D.R 1985. Amphibian species of the world.

Les Semences du Monde: L'Amélioration Participative des Plantes

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

Chacun constitue en outre un point de convergence vers un site web où le CRDI ...... Les comités locaux de recherche agricole (Comité de Investigación Agrícola ...... Subedi, A., Joshi, K.D., Rana, R.B. et M. Subedi, 2001, Participatory plant ...

Nature and composition of interbedded marine basaltic pumice in the

Indian Academy of Sciences (India)

Home; Journals; Journal of Earth System Science; Volume 126; Issue 2. Nature and composition of interbedded marine basaltic pumice in the ~52–50 Ma Vastan lignite sequence, western India: Implication for Early Eocene MORB volcanism offshore Arabian Sea. Sarajit Sensarma Hukam Singh R S Rana Debajyoti Paul ...

Fossil frogs (Anura) from Shanwang (Middle Miocene; Shandong Province, China)

Czech Academy of Sciences Publication Activity Database

Roček, Zbyněk; Dong, L.; Přikryl, Tomáš; Sun, Ch.; Tan, J.; Wang, Y.

2011-01-01

Roč. 44, č. 5 (2011), s. 499-518 ISSN 0016-6995 R&D Projects: GA AV ČR IAA300130705 Institutional research plan: CEZ:AV0Z30130516 Keywords : Anura * Neogene * Bufo * Macropelobates * Rana * Tadpole * East Asia Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.010, year: 2011

Resonance – Journal of Science Education | Indian Academy of ...

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education. A M Jayannavar. Articles written in Resonance – Journal of Science Education. Volume 22 Issue 7 July 2017 pp 659-676 General Article. Second Law, Landauer's Principle and Autonomous Information Machine · Shubashis Rana A M Jayannavar · More Details ...

Bulletin of Materials Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Author Affiliations. Fernando Cunha1 Sohel Rana1 Raul Fangueiro1 2 Graça Vasconcelos2. Fibrous Materials Research Group (FMRG), School of Engineering, University of Minho, Guimarães 4800-058, Portugal; Department of Civil Engineering, University of Minho, Guimarães 4800-058, Portugal ...

Associateship | Indian Academy of Sciences

Indian Academy of Sciences (India)

Date of birth: 21 September 1953. Specialization: Plant Genetics Address during Associateship: Scientist, National Botanical Research, Institute, Rana Prathap Marg, Lucknow 226 001. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

Farm Population of the United States: 1975. Current Population Reports: Farm Population.

Science.gov (United States)

Banks, Vera J.; And Others

Presented via narrative and tabular data, this report includes: Population of the U.S., Total and Farm: 1960-1975; Metropolitan-Nonmetropolitan Residence of the Farm and Nonfarm Population, by Race: 1975; Fertility Characteristics of Farm and Nonfarm Women, by Race: 1975; Persons 14 Years Old and Over Employed in Agriculture, by Farm-Nonfarm…

Population Research.

Science.gov (United States)

National Inst. of Child Health and Human Development (NIH), Bethesda, MD.

The scope of population research as carried on by the National Institute of Child Health and Human Development (NICHD) is set forth in this booklet. Population problems of the world, United States, and the individual are considered along with international population policies based on voluntary family planning programs. NICHD goals for biological…

Factors associated with the catastrophic decline of a cloudforest frog fauna in Guatemala

Directory of Open Access Journals (Sweden)

J.R Mendelson III

2004-12-01

Full Text Available Comparison of recent and historical surveys of frog populations in cloudforest habitat in Sierra de las Minas,Guatemala,indicated population declines and local extirpation of several species.Pathological exams of diseased tadpoles indicated infection by amphibian chytridiomycosis. The local habitat has been severely altered by recent establishment of large-scale leatherleaf fern production.Analysis of water chemistry at our study site suggested increased nitrogenation associated with the leatherleaf industry.Rev.Biol.Trop.52(4:991-1000. Epub 2005 Jun 24.Una comparación entre un inventario anterior y otro reciente de poblaciones de ranas de bosque nublado en la Sierra de Las Minas de Guatemala demostró disminuciones poblacionales y ausencia localizada de varias especies.El examen patológico de un renacuajo muerto indicó infección por un hongo quítrido propio de los anfibios.El hábitat local ha sido gravemente alterado por el establecimiento reciente de producción a gran escala de helechos ornamentales.El análisis químico del agua en el área de estudio señaló un aumento en nitrogenación asociado al cultivo de helechos.

Population policy.

Science.gov (United States)

1987-03-01

Participants in the Seminar on Population Policies for Top-level Policy Makers and Program Managers, meeting in Thailand during January 1987, examined the challenges now facing them regarding the implementation of fertility regulation programs in their respective countries -- Bangladesh, China, India, Indonesia, Malaysia, Nepal, Pakistan, the Philippines, the Republic of Korea, and Thailand. This Seminar was organized to coincide with the completion of an Economic and Social Commission for Asia and the Pacific (ESCAP) study investigating the impact and efficiency of family planning programs in the region. Country studies were reviewed at the Seminar along with policy issues about the status of women, incentive and disincentive programs, and socioeconomic factors affecting fertility. In Bangladesh the government recognizes population growth as its top priority problem related to the socioeconomic development of the country and is working to promote a reorientation strategy from the previous clinic-oriented to a multidimensional family welfare program. China's family planning program seeks to postpone marraige, space the births of children between 3-5 years, and promote the 1-child family. Its goal is to reduce the rate of natural increase from 12/1000 in 1978 to 5/1000 by 1985 and 0 by 2000. India's 7th Five-Year-Plan (1986-90) calls for establishing a 2-child family norm by 2000. In Indonesia the government's population policy includes reducing the rate of population growth, achieving a redistribution of the population, adjusting economic factors, and creating prosperous families. The government of Indonesia reversed its policy to reduce the population growth rate in 1984 and announced its goal of achieving a population of 70 million by 2100 in order to support mass consumption industries. It has created an income tax deduction system favoring large families and maternity benefits for women who have up to 5 children as incentives. Nepal's official policy is to

Ecología reproductiva de Geobatrachus walkeri (Anura: Srabomantidae

Directory of Open Access Journals (Sweden)

Vanesa Pacheco-Florez

2014-03-01

Full Text Available Geobatrachus walkeri es una rana que pertenece a un género monotípico y es endémica de la Sierra Nevada de Santa Marta, Colombia. La especie habita en diferentes microhábitats entre los 2 000 y 3 500m de altitud, incluyendo la hojarasca de una plantación de pinos. Para entender su ecología reproductiva se realizaron ocho muestreos de individuos, que abarcaron las estaciones de lluvias y de sequía y dos tipos de hábitats (bosque secundario y plantación de pino durante 2010-2011. También se incluyeron los datos de cinco muestreos similares obtenidos previamente durante el período 2008-2009. El principal microhábitat donde las ranas se encontraron fue la hoja-rasca de pino, allí escuchamos coros de seis-diez machos durante todos los meses muestreados, y observamos que las ranas tienen actividad diurna y nocturna. Sin importar el año de estudio, la población se compone de neonatos reclutados en varios meses del año, un gran número de juveniles con un amplio rango de tamaños corporales, y un menor número de adultos con un rango más reducido de tamaño corporal. Los análisis histológicos de las gónadas mostraron que el tamaño a la madurez se adquiere cerca de los 18mm LRC para machos y hembras, y que los machos y hembras adultos fueron reproductivos durante todo el muestreo, lo que sugiere un patrón continuo de actividad reproductiva. Sin embargo, durante la estación seca, los túbulos seminíferos presentan un epitelio espermático drásticamente disminuido, aunque contienen abundantes espermatozoides luminales, lo que sugiere una reducción en la producción de espermatozoides en el final de la estación seca. Del mismo modo, las ranas de todas las categorías de edad fueron significativamente más abundantes durante el inicio de la estación seca, mientras que fueron significativamente menos abundantes con el avance de la sequedad, lo que sugiere que una mayor intensidad de la temporada de sequía podría detener

Human Population Problems

Science.gov (United States)

Emmel, Thomas C.; Sligh, Michael M.

1970-01-01

Asserts that overpopulation is the most pressing world problem. Topics discussed include population control in primitive societies, population growth and control in modern societies, methods of motivational population control, consequences of no population control, and mass famines during the 1970's in underdeveloped countries. Cities 33…

Inherent rhythmcity and interstitial cells of Cajal in a frog vein

Indian Academy of Sciences (India)

Interstitial cells of Cajal are responsible for rhythmic contractions of the musculature of the gastrointestinal tract and blood vessels. The existence of these cells and spontaneous rhythmicity were noticed in amphibian vein and the findings are reported in this paper. The postcaval vein was identified in the frog, Rana tigrina ...

Contractual Control in the Supply Chain. On Corporate Social Responsibility, Codes of Conduct, Contracts and (Avoiding) Liability

NARCIS (Netherlands)

Vytopil, A.L.

2015-01-01

This research addresses a number of questions that have been raised in the wake of the Rana Plaza factory collapse. It focuses on the extent of the legal responsibility and liability for CSR violations in the supply chains of MNCs in the Netherlands, England and California (United States). Many MNCs

Journal of Biosciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

The ability of bronze frog Rana temporalis tadpoles (pure or mixed parental lines) to assess the profitability of food habitats and distribute themselves accordingly was tested experimentally using a rectangular choice tank with a non-continuous input design. Food (boiled spinach) was placed at two opposite ends of the ...

Surveys for California red-legged frog and arroyo toad on the Los Padres National Forest

Science.gov (United States)

Valerie K. Hubbartt; Thomas G. Murphey

2005-01-01

Starting in the spring of 1999 through the fall of 2000, USDA Forest Service biologists have conducted surveys throughout the Los Padres National Forest for the federally-listed California red-legged frog (Rana aurora draytonii) and arroyo toad (Bufo californicus). Sites known to have frogs or toads present were monitored for...

sequences in Chickpea

African Journals Online (AJOL)

Milena

quality and concentration of DNA were measured on Nano-Drop ... Author(s) agree that this article remains permanently open access under the terms of the Creative Commons ..... Aggarwal H, Rao A, Kumar A, Singh J, Rana JS, Naik PK, Chhokar V. (2015). ... variance inferred from metric distances among DNA haplotypes:.

Mitochondria in biology and medicine--2012

DEFF Research Database (Denmark)

Madsen, Claus Desler; Rasmussen, Lene Juel

2014-01-01

as biomarkers for the diseases and most important, it opens the possibility of a treatment or a cure for a disease. "Mitochondria in Biology and Medicine" was the title of the second annual conference of Society of Mitochondrial Research and Medicine-India. The conference was organized by Rana P. Singh, Keshav...

Effects of an Awareness Raising Campaign on Intention and Behavioural Determinants for Handwashing

Science.gov (United States)

Seimetz, E.; Kumar, S.; Mosler, H.-J.

2016-01-01

This article assesses the effectiveness of The Great WASH Yatra handwashing awareness raising campaign in India on changing visitors' intention to wash hands with soap after using the toilet and the underlying behavioural determinants. Interviews based on the RANAS (Risk, Attitudes, Norms, Abilities, Self-regulation) model of behaviour change were…

Journal of Biosciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Biosciences. Saqib Mahmood. Articles written in Journal of Biosciences. Volume 40 Issue 3 September 2015 pp 521-530 Articles. Role of leptin G-2548A polymorphism in age- and gender-specific development of obesity · Adeela Shahid Sobia Rana Saqib Mahmood Shahid Saeed · More Details ...

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,...

Lupeol induces S-phase arrest and mitochondria-mediated ...

Indian Academy of Sciences (India)

48

Lupeol induces S-phase arrest and mitochondria-mediated apoptosis in cervical cancer cells. Nupoor Prasad1, Akash Sabarwal2, Umesh C. S. Yadav1, Rana P. Singh2,*. 1School of Life Sciences, Central University of Gujarat, Gandhinagar, Gujarat, India. 2Cancer Biology Laboratory, School of Life Sciences, Jawaharlal ...

Population pharmacogenetics of Ibero-Latinoamerican populations (MESTIFAR 2014).

Science.gov (United States)

Sosa-Macias, Martha; Moya, Graciela E; LLerena, Adrián; Ramírez, Ronald; Terán, Enrique; Peñas-LLedó, Eva M; Tarazona-Santos, Eduardo; Galaviz-Hernández, Carlos; Céspedes-Garro, Carolina; Acosta, Hildaura

2015-01-01

MESTIFAR 2014 28-30 November 2014, Panama City, Panama The CEIBA consortium was created within the Ibero-American network of Pharmacogenetics (RIBEF) to study population pharmacogenetics. The current status of these initiatives and results of the MESTIFAR project were analyzed in Panama, 28-30 November 2014. The MESTIFAR project focused on studying CYPs genetic polymorphisms in populations of different ethnic origin. So far, more than 6000 healthy volunteers have been evaluated, making this one of the largest population pharmacogenomic studies worldwide. Three symposia were organized, 'Pharmacogenetics of indigenous and mestizos populations and its clinical implications', 'Methodological innovation in pharmacogenetics and its application in health', and 'General discussion and concluding remarks', about mechanisms and proposals for training, diffusion of pharmacogenetics for Spanish- and Portuguese-speaking health professionals, and 'bench to bedside' pilot projects.

Molecular Population Genetics.

Science.gov (United States)

Casillas, Sònia; Barbadilla, Antonio

2017-03-01

Molecular population genetics aims to explain genetic variation and molecular evolution from population genetics principles. The field was born 50 years ago with the first measures of genetic variation in allozyme loci, continued with the nucleotide sequencing era, and is currently in the era of population genomics. During this period, molecular population genetics has been revolutionized by progress in data acquisition and theoretical developments. The conceptual elegance of the neutral theory of molecular evolution or the footprint carved by natural selection on the patterns of genetic variation are two examples of the vast number of inspiring findings of population genetics research. Since the inception of the field, Drosophila has been the prominent model species: molecular variation in populations was first described in Drosophila and most of the population genetics hypotheses were tested in Drosophila species. In this review, we describe the main concepts, methods, and landmarks of molecular population genetics, using the Drosophila model as a reference. We describe the different genetic data sets made available by advances in molecular technologies, and the theoretical developments fostered by these data. Finally, we review the results and new insights provided by the population genomics approach, and conclude by enumerating challenges and new lines of inquiry posed by increasingly large population scale sequence data. Copyright © 2017 Casillas and Barbadilla.

Reversão sexual de rã-touro (Rana catesbeiana com hormônio masculinizante misturado à ração de girinos Sexual reversion of bullfrog with masculinizing hormone added to the tadpole ration

Directory of Open Access Journals (Sweden)

Claudio Angelo Agostinho

2001-06-01

Full Text Available Este trabalho consistiu em testar a eficiência de um hormônio masculinizante (17beta-hidróxi-17-metil-andróxi-4-en-3-ona na reversão sexual de girinos de rã-touro (Rana catesbeiana. Foram usados 352 girinos com dois a três meses de idade, nos estádios 30 a 36, para testar quatro níveis de hormônio na ração (0, 30, 60 e 90 mig/g por 45 dias. Após a metamorfose, 167 imagos foram sacrificados e 185 imagos foram criados até a idade de quatro meses e, então, sacrificados. As análises macroscópicas das gônadas e das características sexuais secundárias confirmaram a masculinização nos tratamentos com hormônio. Muitos ovócitos foram observados nos testículos dos imagos revertidos (ovotestis; entretanto, quatro meses após a metamorfose, os ovotestis ocorreram esporadicamente. Concluiu-se que, após a metamorfose, iniciou-se um processo de reabsorção dos ovócitos nos imagos revertidos, culminando com a quase total reabsorção dos ovócitos no quarto mês de idade.This work consisted in testing the efficiency of a masculinizing hormone (17beta-hydroxy-17-methyl-androxy-4-en-3-one in the sex reversal of bullfrog tadpoles. Three hundred and fifty two tadpoles with two or three months old, from the stages 30 to 36, were used to test four levels of hormone in the ration (0, 30, 60 and 90 mug/g, for 45 days. After metamorphosis, 167 juveniles were sacrificed and 185 were reared until the fourth month of age and sacrificed thereafter. Macroscopic analysis of the gonads and secondary traits confirmed the masculinization in the treatments with hormone. Many oocytes were observed in the testes of the masculinized juveniles; however, four months after metamorphosis the ovotestes were sporadic. It was concluded that, after metamorphosis, oocyte reabsorption started in reversed juveniles, culminating in almost total reabsorption at the fourth months.

Ancestral Relationships Using Metafounders: Finite Ancestral Populations and Across Population Relationships.

Science.gov (United States)

Legarra, Andres; Christensen, Ole F; Vitezica, Zulma G; Aguilar, Ignacio; Misztal, Ignacy

2015-06-01

Recent use of genomic (marker-based) relationships shows that relationships exist within and across base population (breeds or lines). However, current treatment of pedigree relationships is unable to consider relationships within or across base populations, although such relationships must exist due to finite size of the ancestral population and connections between populations. This complicates the conciliation of both approaches and, in particular, combining pedigree with genomic relationships. We present a coherent theoretical framework to consider base population in pedigree relationships. We suggest a conceptual framework that considers each ancestral population as a finite-sized pool of gametes. This generates across-individual relationships and contrasts with the classical view which each population is considered as an infinite, unrelated pool. Several ancestral populations may be connected and therefore related. Each ancestral population can be represented as a "metafounder," a pseudo-individual included as founder of the pedigree and similar to an "unknown parent group." Metafounders have self- and across relationships according to a set of parameters, which measure ancestral relationships, i.e., homozygozities within populations and relationships across populations. These parameters can be estimated from existing pedigree and marker genotypes using maximum likelihood or a method based on summary statistics, for arbitrarily complex pedigrees. Equivalences of genetic variance and variance components between the classical and this new parameterization are shown. Segregation variance on crosses of populations is modeled. Efficient algorithms for computation of relationship matrices, their inverses, and inbreeding coefficients are presented. Use of metafounders leads to compatibility of genomic and pedigree relationship matrices and to simple computing algorithms. Examples and code are given. Copyright © 2015 by the Genetics Society of America.

Population Profile of the United States: 1976. Current Population Reports, Population Characteristics, Series P-20, No. 307.

Science.gov (United States)

Bureau of the Census (DOC), Suitland, MD. Population Div.

This booklet summarizes population characteristics of the United States for 1976. A preliminary section of highlights reviews trends in five areas: population growth, social characteristics, population distribution, employment and income, and ethnic groups. The birth rate has declined, and the rate of childlessness has risen. This probably is due…

Detecting population recovery using gametic disequilibrium-based effective population size estimates

Science.gov (United States)

David A. Tallmon; Robin S. Waples; Dave Gregovich; Michael K. Schwartz

2012-01-01

Recovering populations often must meet specific growth rate or abundance targets before their legal status can be changed from endangered or threatened. While the efficacy, power, and performance of population metrics to infer trends in declining populations has received considerable attention, how these same metrics perform when populations are increasing is less...

genotypes for okra yellow vein mosaic virus incidence

African Journals Online (AJOL)

SAM

2014-03-19

Mar 19, 2014 ... by whitefly (Bemisia tabaci Gen.) (Rana et al., 2006). ... Solankey et al. 1337. Table 1. Scale for classifying disease reaction in okra to OYVMV disease. Symptom. Severity grade. Response value. Coefficient of infection. Reaction ..... On the basis of two season research work, it was observed that the okra ...

Algunos temas de investigación a nivel elemental

OpenAIRE

Takeuchi, Yu

2012-01-01

En algunas ramas de la Ciencia como la Biología, la Geología, etc., no es difícil encontrar temas originales de investigación, por ejemplo;  “ una investigación sobre cierta clase de ranas de tres patas que vive exclusivamente en la Sabana de Bogotá ".

Multiple Antigen Peptide Vaccines against Plasmodium falciparum Malaria

Science.gov (United States)

2010-01-01

Robert A. Boykins/ Victoria Majam,l Hong Zheng,1 Rana Chattopadhyay,l Patricia de Ia Vcga,3 J. Kathleen Moch ,J J. David Hayncs,3 Igor M. Belyakov,2...K. Moch , and D. S. Smoot. 2002. Erythroc-ytic malaria growth or invasion inhibition assays with emphasis on suspension culture GIA. Methods Mol. Med

Far East Asia | Page 74 | IDRC - International Development ...

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

Four years after the collapse of the Rana Plaza garment factory killed more than 1,000 people in Bangladesh, a Dhaka-based think tank continues to push for wholesale changes to one of the country's most important industries. Part of an ongoing series of stories about innovative projects in the developing world, ...

The population genomics of begomoviruses: global scale population structure and gene flow

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Prasanna HC

2010-09-01

Full Text Available Abstract Background The rapidly growing availability of diverse full genome sequences from across the world is increasing the feasibility of studying the large-scale population processes that underly observable pattern of virus diversity. In particular, characterizing the genetic structure of virus populations could potentially reveal much about how factors such as geographical distributions, host ranges and gene flow between populations combine to produce the discontinuous patterns of genetic diversity that we perceive as distinct virus species. Among the richest and most diverse full genome datasets that are available is that for the dicotyledonous plant infecting genus, Begomovirus, in the Family Geminiviridae. The begomoviruses all share the same whitefly vector, are highly recombinogenic and are distributed throughout tropical and subtropical regions where they seriously threaten the food security of the world's poorest people. Results We focus here on using a model-based population genetic approach to identify the genetically distinct sub-populations within the global begomovirus meta-population. We demonstrate the existence of at least seven major sub-populations that can further be sub-divided into as many as thirty four significantly differentiated and genetically cohesive minor sub-populations. Using the population structure framework revealed in the present study, we further explored the extent of gene flow and recombination between genetic populations. Conclusions Although geographical barriers are apparently the most significant underlying cause of the seven major population sub-divisions, within the framework of these sub-divisions, we explore patterns of gene flow to reveal that both host range differences and genetic barriers to recombination have probably been major contributors to the minor population sub-divisions that we have identified. We believe that the global Begomovirus population structure revealed here could

[Population and development].

Science.gov (United States)

Castanon Romo, R; Sandoval Navarrete, J

1996-01-01

This broad survey of the debate concerning the relationship between population growth and economic development discusses the history and current status of world population growth, summarizes several influential theoretical positions on the topic, and proposes that redefinition of women's social role is indispensable if worldwide control of population growth is to be achieved. The introductory section discusses the acceleration of population growth in the second half of the 20th century and the increasing concentration of growth in the poor and developing countries. The positions of those who see in population control a means of promoting economic development and political stability are contrasted to the positions of those who believe that a large and growing population is the key to achieving economic and political progress. The international community, facing great uncertainty about the size, distribution, and well-being of the future world population, is increasingly concerned about the effect of growing numbers on the environment and natural resources. The second section summarizes the works of Malthus, Julian Simon, and the Club of Rome, and analyzes the propositions of demographic transition theory. The conclusion notes that despite uncertainty about the future of world population, development, and health, most of the poorest countries have become aware of the desirability of slowing population growth. A broad redefinition of the social role of women will inevitably accompany the worldwide demographic transition.

Population Trends and the Status of Population Policy in Africa.

Science.gov (United States)

Rogge, John R.

1982-01-01

The major trend towards worldwide easing of the birthrate does not include the current population patterns in Africa. The population policies of African nations range along a continuum from totally pronatal to strongly antinatal. However, even antinatal policies have had little effect on the overall spiralling upward population trend. (JA)

Population-based contracting (population health): part II.

Science.gov (United States)

Jacofsky, D J

2017-11-01

Modern healthcare contracting is shifting the responsibility for improving quality, enhancing community health and controlling the total cost of care for patient populations from payers to providers. Population-based contracting involves capitated risk taken across an entire population, such that any included services within the contract are paid for by the risk-bearing entity throughout the term of the agreement. Under such contracts, a risk-bearing entity, which may be a provider group, a hospital or another payer, administers the contract and assumes risk for contractually defined services. These contracts can be structured in various ways, from professional fee capitation to full global per member per month diagnosis-based risk. The entity contracting with the payer must have downstream network contracts to provide the care and facilities that it has agreed to provide. Population health is a very powerful model to reduce waste and costs. It requires a deep understanding of the nuances of such contracting and the appropriate infrastructure to manage both networks and risk. Cite this article: Bone Joint J 2017;99-B:1431-4. ©2017 The British Editorial Society of Bone & Joint Surgery.

Population Neuroscience: Dementia Epidemiology Serving Precision Medicine and Population Health.

Science.gov (United States)

Ganguli, Mary; Albanese, Emiliano; Seshadri, Sudha; Bennett, David A; Lyketsos, Constantine; Kukull, Walter A; Skoog, Ingmar; Hendrie, Hugh C

2018-01-01

Over recent decades, epidemiology has made significant contributions to our understanding of dementia, translating scientific discoveries into population health. Here, we propose reframing dementia epidemiology as "population neuroscience," blending techniques and models from contemporary neuroscience with those of epidemiology and biostatistics. On the basis of emerging evidence and newer paradigms and methods, population neuroscience will minimize the bias typical of traditional clinical research, identify the relatively homogenous subgroups that comprise the general population, and investigate broader and denser phenotypes of dementia and cognitive impairment. Long-term follow-up of sufficiently large study cohorts will allow the identification of cohort effects and critical windows of exposure. Molecular epidemiology and omics will allow us to unravel the key distinctions within and among subgroups and better understand individuals' risk profiles. Interventional epidemiology will allow us to identify the different subgroups that respond to different treatment/prevention strategies. These strategies will inform precision medicine. In addition, insights into interactions between disease biology, personal and environmental factors, and social determinants of health will allow us to measure and track disease in communities and improve population health. By placing neuroscience within a real-world context, population neuroscience can fulfill its potential to serve both precision medicine and population health.

Imaginary populations

OpenAIRE

Martínez-Abraín, Alejandro

2010-01-01

A few years ago, Camus & Lima (2002) wrote an essay to stimulate ecologists to think about how we define and use a fundamental concept in ecology: the population. They concluded, concurring with Berryman (2002), that a population is "a group of individuals of the same species that live together in an area of sufficient size to permit normal dispersal and/or migration behaviour and in which population changes are largely the results of birth and death processes". They pointed out that ecologis...

Population and development.

Science.gov (United States)

Okita, S

1989-03-01

This speech on the life and work of Rafael Salas, who had been the first executive director of the UN Population Fund (UNFPA) and who contributed immensely to global awareness of population as a vital issue, inaugurated the Rafael M. Salas Lecture Series at the UN. Salas was concerned with individual rights and socioeconomic development while maintaining a balance between population and the environment. He built a large multinational assistance program for population activities and increased funding from $2.5 million in 1969 to $175 million to support 2500 projects in 130 developing countries. He organized both the 1974 World Population Conference and the 1984 International Conference on Population. In developing countries malnutrition and poverty are intertwined, lowering productivity and making people prone to diseases. Infant and child mortality rises with the malnutrition of mothers, therefore campaigns modelled after the postwar Japanese efforts are needed to improve nutrition, to train dietitians, and to introduce school lunch programs. Population stabilization could also be achieved in developing countries by raising income levels, although in Latin American countries birth rates have stayed the same despite increasing income. Direct measures are effective in reducing the birth rate: primary school education, increased income, improved nutrition, decline in infant mortality, higher status of women, and decisive governmental population policy. The Club of Rome report The Limits to Growth predicted that sometime in the 21st century a sudden decline in both population and industrial capacity will be reached at the present growth trends.

Population and genomic lessons from genetic analysis of two Indian populations.

Science.gov (United States)

Juyal, Garima; Mondal, Mayukh; Luisi, Pierre; Laayouni, Hafid; Sood, Ajit; Midha, Vandana; Heutink, Peter; Bertranpetit, Jaume; Thelma, B K; Casals, Ferran

2014-10-01

Indian demographic history includes special features such as founder effects, interpopulation segregation, complex social structure with a caste system and elevated frequency of consanguineous marriages. It also presents a higher frequency for some rare mendelian disorders and in the last two decades increased prevalence of some complex disorders. Despite the fact that India represents about one-sixth of the human population, deep genetic studies from this terrain have been scarce. In this study, we analyzed high-density genotyping and whole-exome sequencing data of a North and a South Indian population. Indian populations show higher differentiation levels than those reported between populations of other continents. In this work, we have analyzed its consequences, by specifically assessing the transferability of genetic markers from or to Indian populations. We show that there is limited genetic marker portability from available genetic resources such as HapMap or the 1,000 Genomes Project to Indian populations, which also present an excess of private rare variants. Conversely, tagSNPs show a high level of portability between the two Indian populations, in contrast to the common belief that North and South Indian populations are genetically very different. By estimating kinship from mates and consanguinity in our data from trios, we also describe different patterns of assortative mating and inbreeding in the two populations, in agreement with distinct mating preferences and social structures. In addition, this analysis has allowed us to describe genomic regions under recent adaptive selection, indicating differential adaptive histories for North and South Indian populations. Our findings highlight the importance of considering demography for design and analysis of genetic studies, as well as the need for extending human genetic variation catalogs to new populations and particularly to those with particular demographic histories.

Simulating Population Growth.

Science.gov (United States)

Byington, Scott

1997-01-01

Presents a strategy to help students grasp the important implications of population growth. Involves an interactive demonstration that allows students to experience exponential and logistic population growth followed by a discussion of the implications of population-growth principles. (JRH)

Population dynamics

Directory of Open Access Journals (Sweden)

Cooch, E. G.

2004-06-01

Full Text Available Increases or decreases in the size of populations over space and time are, arguably, the motivation for much of pure and applied ecological research. The fundamental model for the dynamics of any population is straightforward: the net change over time in the abundance of some population is the simple difference between the number of additions (individuals entering the population minus the number of subtractions (individuals leaving the population. Of course, the precise nature of the pattern and process of these additions and subtractions is often complex, and population biology is often replete with fairly dense mathematical representations of both processes. While there is no doubt that analysis of such abstract descriptions of populations has been of considerable value in advancing our, there has often existed a palpable discomfort when the ‘beautiful math’ is faced with the often ‘ugly realities’ of empirical data. In some cases, this attempted merger is abandoned altogether, because of the paucity of ‘good empirical data’ with which the theoretician can modify and evaluate more conceptually–based models. In some cases, the lack of ‘data’ is more accurately represented as a lack of robust estimates of one or more parameters. It is in this arena that methods developed to analyze multiple encounter data from individually marked organisms has seen perhaps the greatest advances. These methods have rapidly evolved to facilitate not only estimation of one or more vital rates, critical to population modeling and analysis, but also to allow for direct estimation of both the dynamics of populations (e.g., Pradel, 1996, and factors influencing those dynamics (e.g., Nichols et al., 2000. The interconnections between the various vital rates, their estimation, and incorporation into models, was the general subject of our plenary presentation by Hal Caswell (Caswell & Fujiwara, 2004. Caswell notes that although interest has traditionally

Endocrine control of active sodium transport across frog skin; Le controle endocrinien du transport actif de sodium a travers la peau de grenouille

Energy Technology Data Exchange (ETDEWEB)

Maetz, J. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1959-07-01

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) [French] I. Action des peptides neurohypophysaires chez Rana esculenta. 1) Le transport actif de Na est sensible a l'action de l'ocytocine mais non a l'hormone antidiuretique. 2) La posthypophyse de ces grenouilles contient un facteur plus specifique encore, puisque 12 fois plus actif que l'ocytocine. 3) Ce facteur est cependant tres voisin de l'ocytocine au point de vue chimique. lI. Action des corticoides surrenaliens chez Rana Esculenta. 1) L'adaptation des grenouilles a un milieu riche en sel a pour effet une diminution considerable du transport actif de sodium, visible in vivo et in vitro. 2) L'injection d'aldosterone a des grenouilles adaptees dans ces conditions restaure le transport actif a un niveau comparable a celui que l'on observe chez les animaux conserves dans de l'eau courante. 3) Ces faits suggerent que la surcharge en NaCI produirait chez les amphibiens, comme chez les mammiferes, une mise au repos de la fonction mineralotrope de la surrenale. (auteur)

Endocrine control of active sodium transport across frog skin; Le controle endocrinien du transport actif de sodium a travers la peau de grenouille

Energy Technology Data Exchange (ETDEWEB)

Maetz, J [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1959-07-01

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) [French] I. Action des peptides neurohypophysaires chez Rana esculenta. 1) Le transport actif de Na est sensible a l'action de l'ocytocine mais non a l'hormone antidiuretique. 2) La posthypophyse de ces grenouilles contient un facteur plus specifique encore, puisque 12 fois plus actif que l'ocytocine. 3) Ce facteur est cependant tres voisin de l'ocytocine au point de vue chimique. lI. Action des corticoides surrenaliens chez Rana Esculenta. 1) L'adaptation des grenouilles a un milieu riche en sel a pour effet une diminution considerable du transport actif de sodium, visible in vivo et in vitro. 2) L'injection d'aldosterone a des grenouilles adaptees dans ces conditions restaure le transport actif a un niveau comparable a celui que l'on observe chez les animaux conserves dans de l'eau courante. 3) Ces faits suggerent que la surcharge en NaCI produirait chez les amphibiens, comme chez les mammiferes, une mise au repos de la fonction mineralotrope de la surrenale. (auteur)

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, ...

Moving beyond Boycotts: Strategies for Shared Responsibility in the Collegiate Apparel Industry

Science.gov (United States)

Kelley, Scott P.

2014-01-01

The 2013 factory collapse at Rana Plaza in Bangladesh is a painful reminder that labor issues in the apparel industry are abundant and troubling. Catholic colleges and universities (CCUs) are confronted with the reality that many apparel manufacturers can operate in stark contrast to the vision of economic justice found in Catholic social thought…

Developing probabilistic models to predict amphibian site occupancy in a patchy landscape

Science.gov (United States)

R. A. Knapp; K.R. Matthews; H. K. Preisler; R. Jellison

2003-01-01

Abstract. Human-caused fragmentation of habitats is threatening an increasing number of animal and plant species, making an understanding of the factors influencing patch occupancy ever more important. The overall goal of the current study was to develop probabilistic models of patch occupancy for the mountain yellow-legged frog (Rana muscosa). This once-common species...

New Fellows and Honorary Fellow

Indian Academy of Sciences (India)

Home; Fellowship. Fellow Profile. Elected: 1943 Section: Earth & Planetary Sciences. Rana, Khadag Narsingh Jung Bahadur. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year meeting of the Academy will be held from 29–30 June 2018 in ...

Observations on the oesophageal glands in some Tanzanian anurans

African Journals Online (AJOL)

in Hyla, Rana, BUfo, Pelobates and Triturus more pep- sinogen was produced in these glands than in the gastric glands. The aim of the present study was to obtain data on the occurrence of oesophageal glands in selected anurans from Tanzania and to compare their structure with the better known gastric glands. Materials ...

Proceedings – Mathematical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Proceedings – Mathematical Sciences; Volume 119; Issue 1. Issue front cover thumbnail. Volume 119, Issue 1. February 2009, pages 1-135. pp 1-7. On an Extension of a Combinatorial Identity · M Rana A K Agarwal · More Details Abstract Fulltext PDF. Using Frobenius partitions we extend the main results ...

Quantitation of ranaviruses in cell culture and tissue samples

DEFF Research Database (Denmark)

Holopainen, Riikka; Honkanen, Jarno; Jensen, Britt Bang

2011-01-01

; European sheatfish virus, ESV; Frog virus 3, FV3; Bohle iridovirus, BIV; Doctor fish virus, DFV; Guppy virus 6, GV6; Pike-perch iridovirus, PPIV; Rana esculenta virus Italy 282/I02, REV282/I02 and Short-finned eel ranavirus, SERV) were detected with the qPCR assay. In addition, two fish cell lines...

[Population: evolution of Rwandan attitudes or the adaptation of the Rwanda population to population growth].

Science.gov (United States)

Ngendakumana, M

1988-04-01

A consequence of the increasing pressure on Rwanda's ecosystem resulting from population growth has been that demographic factors have played a significant role in modifying attitudes and beliefs of the population. The history of Rwanda demonstrates a constant struggle for survival in the face of increasing population pressure. Migration, colonization of new agricultural lands, adoption of new crops and new forms of animal husbandry have been responses to population pressures. Recent unprecedented population growth has exceeded the capacity of older systems of cultivation and combinations of agricultural and animal husbandry to support the population. Smaller animals have largely replaced the cattle that once roamed freely in extensive pastures, and new techniques of stabling animals, use of organic or chemical fertilizers, and new tools adapted to the shrinking size of farm plots have represented responses to the new demographic realities. The concept of the family is likewise undergoing modification in the face of population growth and modernization. Children, who once were valued as a source of labor and constrained to conform to the wishes of the parents in return for the eventual inheritance of the goods and livelihood, now increasingly look beyond the household for education and employment. Family land holdings have become too small to support all the members with a claim on them. The greater distances between family members inevitably mean that relations between them lose closeness. The choice of a marriage partner is increasingly assumed by the young people themselves and not by their families. Old traditions of food sharing and hospitality have been curtailed because of the increasing scarcity of food. Despite the changes engendered by increasing population pressure, pronatalist sentiments are still widespread. But the desire to assure the future of each child rather than to await his services, a new conception of women less dependent on their reproductive

Osteología, taxonomía y relaciones filogenéticas de las ranas del género Telmatobufo (Leptodactylidae Osteology, taxonomy and phylogenetic relationships of the frog genus Telmatobufo (Leptodactylidae

Directory of Open Access Journals (Sweden)

J. RAMÓN FORMAS

2001-06-01

Full Text Available Se hizo un análisis osteológico de las especies del género Telmatobufo (T. australis, T. bullocki, T. venustus, el que completa la definición genérica fundamentada exclusivamente en la osteología de T. bullocki y caracteres larvarios. Para cada especie se entrega nueva información distribucional, ecológica, reproductiva, morfométrica, cromosómica, alozímica y molecular. Se presenta una clave para identificar individuos adultos de las tres especies de Telmatobufo. Se publica por primera vez una lámina de Philippi perdida por casi un siglo, lo que permite aclarar de manera definitiva la identidad taxonómica de T. venustus. Con las distancias de Mahalanobis y las distancias genéticas de Rogers se determinan las similitudes morfológicas y genéticas entre las especies de Telmatobufo. Usando las secuencias para ARN 12S mitocondrial, frecuencias alélicas polarizadas de genes estructurales y caracteres morfológicos (osteológicos y morfológicos externos se propone una hipótesis de relaciones filogenéticas basada en los principios de máxima parsimonia y máxima probabilidad. Finalmente se entrega una proposición acerca de la especiación e historia evolutiva de este grupo de ranas endémicas de los bosques templados del centro-sur de ChileAn osteological analysis of the three species of the genus Telmatobufo (T. australis, T. bullocki, and T. venustus was done. That analysis completes the generic definition based mainly on the osteology of T. bullocki and on morphological larval characters. New information on morphometry, chromosomes, reproductive biology, ecology, geographical range, allozymes, and molecular data is provided for each species. A key for the taxonomic determination of adult specimens of Telmatobufo is also presented. An unedited original plate by R.A. Philippi, lost for almost a century, is published for the first time; this plate allowed the restatement of the taxonomical identity of T. venustus. Mahalanobis

The population threat.

Science.gov (United States)

Teitelbaum, M S

1992-01-01

Commentary is provided on the challenges faced by the new Clinton administration in formulating US key foreign policy initiatives. There is an urgent need to provide balanced and effective foreign aid for reducing high fertility rates in the developing world. There is also a need to effectively monitor the large migrations of populations. Over the past 10 years, the US has not been actively practicing world leadership on population issues. 3 changes in 1993 give impetus to redirect foreign policy: 1) the waning influence of fringe groups who controlled population issues; 2) the campaign promises to restore UN population stabilization programs; and 3) the evidence from the Persian Gulf and Yugoslavia that demographic issues require planning and assessment. Global population growth has been concentrated in the past 40 years, in part due to mortality declines and sustained high fertility. Of significance is the rapidness and momentum of growth. A high percentage are and will be children. Urban population is also growing rapidly in high fertility countries. Countries with high fertility and significant rural-to-urban migration also have large international migrations. The evolution of policy since the 1950s, which for the most part ignored population issues, is discussed. The American debates have been charged with emotionalism: about human sexuality, legitimacy of voluntary fertility control, the role and status of women and men, abortion, intergenerational transfer of obligations, ethnic solidarity and the sovereignty of national borders, and the proper roles of the state versus the marketplace. There have been over 200 years of ideological argument over population issues. The Malthusian argument was that large population size did not increase prosperity, and growth should be limited. The Marxist-Leninist position was that contraception was Malthusian, abortion was a woman's right, and population growth was neutral. By late 1970 the Chinese Maoists adopted the moral

The use of artificial impoundments by two amphibian species in the Delaware Water Gap National Recreation Area

Science.gov (United States)

Julian, J.T.; Snyder, C.D.; Young, J.A.

2006-01-01

We compared breeding activity of Ambystoma maculatum (Spotted Salamander) and Rana sylvatica (Wood Frog) in artificial impoundments to patterns in natural wetlands over a three-year period in the Delaware Water Gap National Recreation Area. Rana sylvatica were 5.6 times more likely to use natural bodies of water for breeding than artificial impoundments, while A. maculatum were 2.7 times more likely to use natural bodies of water. Both species were approximately 9 times more likely to breed in fishless bodies of water than in waters with predatory fish. Ambystoma maculatum were 6 times more likely to breed in wetlands with more stable seasonal hydroperiods, while R. sylvatica were only 2 times more likely to do so. We conclude that the high likelihood of fish presence in impoundments was the primary explanation for why both species were less likely to use impoundments than natural wetlands, while the tendency of A. maculatum to avoid natural wetlands with shorter hydroperiods explained why differences in use between pond types was more pronounced for R. sylvatica.

Toxicity of road salt to Nova Scotia amphibians

International Nuclear Information System (INIS)

Collins, Sara J.; Russell, Ronald W.

2009-01-01

The deposition of chemical pollutants into roadside wetlands from runoff is a current environmental concern. In northern latitudes, a major pollutant in runoff water is salt (NaCl), used as de-icing agents. In this study, 26 roadside ponds were surveyed for amphibian species richness and chloride concentration. Acute toxicity tests (LC 50 ) were performed on five locally common amphibian species using a range of environmentally significant NaCl concentrations. Field surveys indicated that spotted salamanders (Ambystoma maculatum) and wood frogs (Rana sylvatica) did not occupy high chloride ponds. American toads (Bufo americanus) showed no pond preference based on chloride concentration. Acute toxicity tests showed spotted salamanders and wood frogs were most sensitive to chloride, and American toads were the least. Spring peepers (Pseudacris crucifer) and green frogs (Rana clamitans) showed intermediate sensitivities. We concluded that chloride concentrations in ponds due to application of de-icing salts, influenced community structure by excluding salt intolerant species. - Salt toxicity is presented as a mechanism affecting the distribution of amphibians and structure of amphibian communities in roadside wetlands

Involvement of adrenal hormones in tissue respiration of sub-tropical hibernating and non-hibernating species of frogs.

Science.gov (United States)

Gupta, B B; Mahanta, A

1997-03-01

Effects of norepinephrine (NE), epinephrine (EP), corticosterone and cortisol were studied both in vivo and in vitro on the rate of oxygen consumption of tissues (liver, skeletal muscle and kidney) of sub-tropical Indian frogs Rana limnocharis (a hibernating species) and Rana cyanophlyctis (a non-hibernating species) exposed to natural climatic conditions during winter and summer/rainy seasons. Further, the effects of NE and EP were also studied in vitro in the presence of specific beta- and alpha-adrenergic antagonists (propranolol and prazosin). NE, EP and corticosterone, when administered in vivo or in vitro, significantly stimulated the respiratory rate of the tissues of both the species irrespective of the seasons/temperature. Results suggest that NE, EP and corticosterone are directly involved in regulation of the energy metabolism of both hibernating and non-hibernating species of sub-tropical frogs. The calorigenic action of NE and EP seems to be mediated by both beta- and alpha-adrenergic receptors. However, the temporal involvement of beta- and alpha-adrenergic receptors seems to be tissue-dependent.

Matrix population models from 20 studies of perennial plant populations

Science.gov (United States)

Ellis, Martha M.; Williams, Jennifer L.; Lesica, Peter; Bell, Timothy J.; Bierzychudek, Paulette; Bowles, Marlin; Crone, Elizabeth E.; Doak, Daniel F.; Ehrlen, Johan; Ellis-Adam, Albertine; McEachern, Kathryn; Ganesan, Rengaian; Latham, Penelope; Luijten, Sheila; Kaye, Thomas N.; Knight, Tiffany M.; Menges, Eric S.; Morris, William F.; den Nijs, Hans; Oostermeijer, Gerard; Quintana-Ascencio, Pedro F.; Shelly, J. Stephen; Stanley, Amanda; Thorpe, Andrea; Tamara, Ticktin; Valverde, Teresa; Weekley, Carl W.

2012-01-01

Demographic transition matrices are one of the most commonly applied population models for both basic and applied ecological research. The relatively simple framework of these models and simple, easily interpretable summary statistics they produce have prompted the wide use of these models across an exceptionally broad range of taxa. Here, we provide annual transition matrices and observed stage structures/population sizes for 20 perennial plant species which have been the focal species for long-term demographic monitoring. These data were assembled as part of the 'Testing Matrix Models' working group through the National Center for Ecological Analysis and Synthesis (NCEAS). In sum, these data represent 82 populations with >460 total population-years of data. It is our hope that making these data available will help promote and improve our ability to monitor and understand plant population dynamics.

Standard Populations (Millions) for Age-Adjustment - SEER Population Datasets

Science.gov (United States)

Download files containing standard population data for use in statististical software. The files contain the same data distributed with SEER*Stat software. You can also view the standard populations, either 19 age groups or single ages.

Population structure and genomic inbreeding in nine Swiss dairy cattle populations.

Science.gov (United States)

Signer-Hasler, Heidi; Burren, Alexander; Neuditschko, Markus; Frischknecht, Mirjam; Garrick, Dorian; Stricker, Christian; Gredler, Birgit; Bapst, Beat; Flury, Christine

2017-11-07

Domestication, breed formation and intensive selection have resulted in divergent cattle breeds that likely exhibit their own genomic signatures. In this study, we used genotypes from 27,612 autosomal single nucleotide polymorphisms to characterize population structure based on 9214 sires representing nine Swiss dairy cattle populations: Brown Swiss (BS), Braunvieh (BV), Original Braunvieh (OB), Holstein (HO), Red Holstein (RH), Swiss Fleckvieh (SF), Simmental (SI), Eringer (ER) and Evolèner (EV). Genomic inbreeding (F ROH ) and signatures of selection were determined by calculating runs of homozygosity (ROH). The results build the basis for a better understanding of the genetic development of Swiss dairy cattle populations and highlight differences between the original populations (i.e. OB, SI, ER and EV) and those that have become more popular in Switzerland as currently reflected by their larger populations (i.e. BS, BV, HO, RH and SF). The levels of genetic diversity were highest and lowest in the SF and BS breeds, respectively. Based on F ST values, we conclude that, among all pairwise comparisons, BS and HO (0.156) differ more than the other pairs of populations. The original Swiss cattle populations OB, SI, ER, and EV are clearly genetically separated from the Swiss cattle populations that are now more common and represented by larger numbers of cows. Mean levels of F ROH ranged from 0.027 (ER) to 0.091 (BS). Three of the original Swiss cattle populations, ER (F ROH : 0.027), OB (F ROH : 0.029), and SI (F ROH : 0.039), showed low levels of genomic inbreeding, whereas it was much higher in EV (F ROH : 0.074). Private signatures of selection for the original Swiss cattle populations are reported for BTA4, 5, 11 and 26. The low levels of genomic inbreeding observed in the original Swiss cattle populations ER, OB and SI compared to the other breeds are explained by a lesser use of artificial insemination and greater use of natural service. Natural service

LOS FANTASMAS EN RANAS DE ARISTÓFANES

OpenAIRE

Soraya Planchas Gallarte

2015-01-01

THE GHOSTS IN ARISTOPHANES’ FROGS. The aim of the following paper is to present and analyze the passages of the comedies of Aristophanes related to ghostly apparitions. By offering an overview of this issue, so recurrent among classical authors, we will be able to sketch, on the one hand, how the Athenian comic playwright configures this topic in one of his works. On the other, by contextualizing Aristophanes’ treatment of ghosts in his genre, we will have the opportunity of focusing ...

U.S. Population Data 1969-2016 - SEER Population Data

Science.gov (United States)

Download county population estimates used in SEER*Stat to calculate cancer incidence and mortality rates. The estimates are a modification of the U.S. Census Bureau's Population Estimates Program, in collaboration with National Center for Health Statistics.

Population and prehistory II: space-limited human populations in constant environments.

Science.gov (United States)

Puleston, Cedric O; Tuljapurkar, Shripad

2008-09-01

We present a population model to examine the forces that determined the quality and quantity of human life in early agricultural societies where cultivable area is limited. The model is driven by the non-linear and interdependent relationships between the age distribution of a population, its behavior and technology, and the nature of its environment. The common currency in the model is the production of food, on which age-specific rates of birth and death depend. There is a single non-trivial equilibrium population at which productivity balances caloric needs. One of the most powerful controls on equilibrium hunger level is fertility control. Gains against hunger are accompanied by decreases in population size. Increasing worker productivity does increase equilibrium population size but does not improve welfare at equilibrium. As a case study we apply the model to the population of a Polynesian valley before European contact.

[Economic growth with zero population growth and with declining population].

Science.gov (United States)

Kurz, R

1982-05-01

The effects of both zero population growth and a declining population on economic growth are considered. Although the neoclassical theory of economic growth leads to optimistic results in such cases, the author suggests that this theory cannot be used as a basis for political action. The need for further research into the economic effects of a stationary or declining population is stressed. (summary in ENG)

Population and prehistory I: Food-dependent population growth in constant environments.

Science.gov (United States)

Lee, Charlotte T; Tuljapurkar, Shripad

2008-06-01

We present a demographic model that describes the feedbacks between food supply, human mortality and fertility rates, and labor availability in expanding populations, where arable land area is not limiting. This model provides a quantitative framework to describe how environment, technology, and culture interact to influence the fates of preindustrial agricultural populations. We present equilibrium conditions and derive approximations for the equilibrium population growth rate, food availability, and other food-dependent measures of population well-being. We examine how the approximations respond to environmental changes and to human choices, and find that the impact of environmental quality depends upon whether it manifests through agricultural yield or maximum (food-independent) survival rates. Human choices can complement or offset environmental effects: greater labor investments increase both population growth and well-being, and therefore can counteract lower agricultural yield, while fertility control decreases the growth rate but can increase or decrease well-being. Finally we establish equilibrium stability criteria, and argue that the potential for loss of local stability at low population growth rates could have important consequences for populations that suffer significant environmental or demographic shocks.

(Ciliophora: Peritrichia) from the urinary bladder of Bufo gutturalis

African Journals Online (AJOL)

1988-09-07

Sep 7, 1988 ... vesicola Suzuki, 1950 from Rana rugosa (Suzuki 1950). The question arises whether T. dampanula sp. n. may possibly be the same species as observed by Fantham. (1924) in the urinary bladder of B. regularis, i.e. T. bufonis. Owing to the fact that none of the character- istics provided by Fantham (1924) ...

Density-dependent growth and metamorphosis in the larval bronze ...

Indian Academy of Sciences (India)

Effects of density and kinship on growth and metamorphosis in tadpoles of Rana temporalis were studied in a 2 × 4 factorial experiment. Fifteen egg masses were collected from streams in the Western Ghat region of south India. The tadpoles were raised as siblings or in groups of non-siblings at increasing density levels, viz ...

Occupational and Environmental Risks from Mancozeb in Aviation ...

African Journals Online (AJOL)

1Colegio de Postgraduados Campus Tabasco, Periferico Carlos A. Molina S/N Carr. Cardenas-Huimanguillo Km 3.5. H. Cárdenas, 2Universidad Juárez Autónoma de Tabasco División Académica de Ciencias Biológicas, Carr. ..... Listed California Red Legged Frog (Rana aurora ... de Investigación Agropecuaria; 2005.

Working group report: High energy and collider physics

Indian Academy of Sciences (India)

in such a high value of tan β in the present investigation as the loss of light ..... 1 de- cays for θt = 130◦, and tan β = 10: in (a) as a function of φ1 for M2 = 225 ..... rana masses of the neutrinos can be generated both at the tree-level and at the.

Terrestrial movements and habitat use of gopher frogs in longleaf pine forests: a comparative study of juveniles and adults

Science.gov (United States)

Elizabeth A. Roznik; Steve A. Johnson; Cathryn H. Greenberg; George W. Tanner

2009-01-01

Many animals exhibit changes in patterns of movement and habitat use as they age, and understanding such ontogenetic shifts is important for ensuring that habitat management is appropriate for all life stages. We used radiotelemetry to study movements and habitat use of juvenile and adult gopher frogs (Rana capito) as they migrated from the same ponds following...

Winners and losers in the complex web of global supply chains.

Science.gov (United States)

Glendon, Lee

2013-01-01

This paper discusses how supply chain, risk and business continuity professionals can collaboratively address the consequences of increasing supply chain complexity in order to deliver both resilient and sustainable supply chains. The paper identifies the key drivers of complexity supported by recent case examples, including the equine DNA scandal and the Rana Plaza tragedy in Bangladesh.

Nematopsis temporariae (Gregarinasina, Apicomplexa, Alveolata) is an intracellular infectious agent of tadpole livers

Czech Academy of Sciences Publication Activity Database

Chambouvet, A.; Valigurová, A.; Pinheiro, L. M.; Richards, T.A.; Jirků, Miloslav

2016-01-01

Roč. 8, č. 5 (2016), s. 675-679 ISSN 1758-2229 R&D Projects: GA ČR(CZ) GBP505/12/G112 Institutional support: RVO:60077344 Keywords : phylogeny * eukaryotes * parasites * declines * disease Subject RIV: EG - Zoology OBOR OECD: Zoology Impact factor: 3.363, year: 2016

Population structure and genetic diversity of native and invasive populations of Solanum rostratum (Solanaceae.

Directory of Open Access Journals (Sweden)

Jiali Zhao

Full Text Available We investigate native and introduced populations of Solanum rostratum, an annual, self-compatible plant that has been introduced around the globe. This study is the first to compare the genetic diversity of Solanum rostratum between native and introduced populations. We aim to (1 determine the level of genetic diversity across the studied regions; (2 explore the likely origins of invasive populations in China; and (3 investigate whether there is the evidence of multiple introductions into China.We genotyped 329 individuals at 10 microsatellite loci to determine the levels of genetic diversity and to investigate population structure of native and introduced populations of S. rostratum. We studied five populations in each of three regions across two continents: Mexico, the U.S.A. and China.We found the highest genetic diversity among Mexican populations of S. rostratum. Genetic diversity was significantly lower in Chinese and U.S.A. populations, but we found no regional difference in inbreeding coefficients (F IS or population differentiation (F ST. Population structure analyses indicate that Chinese and U.S.A. populations are more closely related to each other than to sampled Mexican populations, revealing that introduced populations in China share an origin with the sampled U.S.A. populations. The distinctiveness between some introduced populations indicates multiple introductions of S. rostratum into China.

Estimating Traveler Populations at Airport and Cruise Terminals for Population Distribution and Dynamics

Energy Technology Data Exchange (ETDEWEB)

Jochem, Warren C [ORNL; Sims, Kelly M [ORNL; Bright, Eddie A [ORNL; Urban, Marie L [ORNL; Rose, Amy N [ORNL; Coleman, Phil R [ORNL; Bhaduri, Budhendra L [ORNL

2013-01-01

In recent years, uses of high-resolution population distribution databases are increasing steadily for environmental, socioeconomic, public health, and disaster-related research and operations. With the development of daytime population distribution, temporal resolution of such databases has been improved. However, the lack of incorporation of transitional population, namely business and leisure travelers, leaves a significant population unaccounted for within the critical infrastructure networks, such as at transportation hubs. This paper presents two general methodologies for estimating passenger populations in airport and cruise port terminals at a high temporal resolution which can be incorporated into existing population distribution models. The methodologies are geographically scalable and are based on, and demonstrate how, two different transportation hubs with disparate temporal population dynamics can be modeled utilizing publicly available databases including novel data sources of flight activity from the Internet which are updated in near-real time. The airport population estimation model shows great potential for rapid implementation for a large collection of airports on a national scale, and the results suggest reasonable accuracy in the estimated passenger traffic. By incorporating population dynamics at high temporal resolutions into population distribution models, we hope to improve the estimates of populations exposed to or at risk to disasters, thereby improving emergency planning and response, and leading to more informed policy decisions.

Impact of population growth and population ethics on climate change mitigation policy.

Science.gov (United States)

Scovronick, Noah; Budolfson, Mark B; Dennig, Francis; Fleurbaey, Marc; Siebert, Asher; Socolow, Robert H; Spears, Dean; Wagner, Fabian

2017-11-14

Future population growth is uncertain and matters for climate policy: higher growth entails more emissions and means more people will be vulnerable to climate-related impacts. We show that how future population is valued importantly determines mitigation decisions. Using the Dynamic Integrated Climate-Economy model, we explore two approaches to valuing population: a discounted version of total utilitarianism (TU), which considers total wellbeing and is standard in social cost of carbon dioxide (SCC) models, and of average utilitarianism (AU), which ignores population size and sums only each time period's discounted average wellbeing. Under both approaches, as population increases the SCC increases, but optimal peak temperature decreases. The effect is larger under TU, because it responds to the fact that a larger population means climate change hurts more people: for example, in 2025, assuming the United Nations (UN)-high rather than UN-low population scenario entails an increase in the SCC of 85% under TU vs. 5% under AU. The difference in the SCC between the two population scenarios under TU is comparable to commonly debated decisions regarding time discounting. Additionally, we estimate the avoided mitigation costs implied by plausible reductions in population growth, finding that large near-term savings ($billions annually) occur under TU; savings under AU emerge in the more distant future. These savings are larger than spending shortfalls for human development policies that may lower fertility. Finally, we show that whether lowering population growth entails overall improvements in wellbeing-rather than merely cost savings-again depends on the ethical approach to valuing population. Copyright © 2017 the Author(s). Published by PNAS.

Population Education Country Programmes.

Science.gov (United States)

Population Education in Asia and the Pacific Newsletter, 1983

1983-01-01

Describes population programs in Afghanistan (nonformal, population education literacy program), India (problems in planning/managing population education in higher education), Indonesia (training for secondary/out-of-school inspectors), and Pakistan (integration of population education into school curricula). Programs in China, Korea, Vietnam,…

Iowa Population Trends.

Science.gov (United States)

Tait, John L.; Johnson, Arthur H.

The trends in population distribution and the composition of Iowa's population are reported in this document in order to provide the leaders and citizens of Iowa with information to assist them in making decisions relating to growth and development. Birth and death rates, rural and urban residence, population by race, and age structure are…

Roles of patch characteristics, drought frequency, and restoration in long-term trends of a widespread amphibian

Science.gov (United States)

Hossack, Blake R.; Adams, Michael J.; Pearl, Christopher A.; Pilliod, David S.; Corn, P. Stephen; , KRISTINE W. WILSON; , EVELYN L. BULL; , KRISTIN LOHR; , DEBRA PATLA; , JASON JONES

2013-01-01

Despite the high profile of amphibian declines and the increasing threat of drought and fragmentation to aquatic ecosystems, few studies have examined long-term rates of change for a single species across a large geographic area. We analyzed growth in annual egg-mass counts of the Columbia spotted frog (Rana luteiventris) across the northwestern United States, an area encompassing 3 genetic clades. On the basis of data collected by multiple partners from 98 water bodies between 1991 and 2011, we used state-space and linear-regression models to measure effects of patch characteristics, frequency of summer drought, and wetland restoration on population growth. Abundance increased in the 2 clades with greatest decline history, but declined where populations are considered most secure. Population growth was negatively associated with temporary hydroperiods and landscape modification (measured by the human footprint index), but was similar in modified and natural water bodies. The effect of drought was mediated by the size of the water body: populations in large water bodies maintained positive growth despite drought, whereas drought magnified declines in small water bodies. Rapid growth in restored wetlands in areas of historical population declines provided strong evidence of successful management. Our results highlight the importance of maintaining large areas of habitat and underscore the greater vulnerability of small areas of habitat to environmental stochasticity. Similar long-term growth rates in modified and natural water bodies and rapid, positive responses to restoration suggest pond construction and other forms of management can effectively increase population growth. These tools are likely to become increasingly important to mitigate effects of increased drought expected from global climate change.

Population demographics of two local South Carolina mourning dove populations

Science.gov (United States)

McGowan, D.P.; Otis, D.L.

1998-01-01

The mourning dove (Zenaida macroura) call-count index had a significant (P 2,300 doves and examined >6,000 individuals during harvest bag checks. An age-specific band recovery model with time- and area-specific recovery rates, and constant survival rates, was chosen for estimation via Akaike's Information Criterion (AIC), likelihood ratio, and goodness-of-fit criteria. After-hatching-year (AHY) annual survival rate was 0.359 (SE = 0.056), and hatching-year (HY) annual survival rate was 0.118 (SE = 0.042). Average estimated recruitment per adult female into the prehunting season population was 3.40 (SE = 1.25) and 2.32 (SE = 0.46) for the 2 study areas. Our movement data support earlier hypotheses of nonmigratory breeding and harvested populations in South Carolina. Low survival rates and estimated population growth rate in the study areas may be representative only of small-scale areas that are heavily managed for dove hunting. Source-sink theory was used to develop a model of region-wide populations that is composed of source areas with positive growth rates and sink areas of declining growth. We suggest management of mourning doves in the Southeast might benefit from improved understanding of local population dynamics, as opposed to regional-scale population demographics.

Population redistribution in Nigeria.

Science.gov (United States)

Adebayo, A

1984-07-01

One of the major consequences of the reorganization of Nigeria from 4 states into 12 states in 1967 and then into 19 states in the late 1970s was the redistribution of the Nigerian population. Prior to 1967 Nigeria's rural population migrated primarily to the 4 state capitals of Kaduna, Ibadan, Enugu, Benin City and to the federal capital of Lagos. The creation of additional states, each with their own capital, provided new urban environments where migrants from rural areas were afforded opportunities for employment and social mobility. Between 1960-1980, World Bank estimates indicate that 1) population in Nigerian cityes of over 500,000 population increased from 22-57%; 2) the number of cities with a population of 500,000 or more increased from 2 to 9 and 3) the urban population increased from 13-20%. Given Nigeria's estimated population growth rate of 3.6%/year, it is imperative that the goverment continue its decentralization efforts. Tables show 1) population by region based on the 1963 census; 2) estimated population of the 19 state capitals for 1963 and 1975; and 3) estimated population of the areas included in each of the 19 states for 196o, 1977, 1979, and 19819

Patterns of admixture and population structure in native populations of Northwest North America.

Directory of Open Access Journals (Sweden)

Paul Verdu

2014-08-01

Full Text Available The initial contact of European populations with indigenous populations of the Americas produced diverse admixture processes across North, Central, and South America. Recent studies have examined the genetic structure of indigenous populations of Latin America and the Caribbean and their admixed descendants, reporting on the genomic impact of the history of admixture with colonizing populations of European and African ancestry. However, relatively little genomic research has been conducted on admixture in indigenous North American populations. In this study, we analyze genomic data at 475,109 single-nucleotide polymorphisms sampled in indigenous peoples of the Pacific Northwest in British Columbia and Southeast Alaska, populations with a well-documented history of contact with European and Asian traders, fishermen, and contract laborers. We find that the indigenous populations of the Pacific Northwest have higher gene diversity than Latin American indigenous populations. Among the Pacific Northwest populations, interior groups provide more evidence for East Asian admixture, whereas coastal groups have higher levels of European admixture. In contrast with many Latin American indigenous populations, the variance of admixture is high in each of the Pacific Northwest indigenous populations, as expected for recent and ongoing admixture processes. The results reveal some similarities but notable differences between admixture patterns in the Pacific Northwest and those in Latin America, contributing to a more detailed understanding of the genomic consequences of European colonization events throughout the Americas.

Why Population in 1974?

Science.gov (United States)

O'Connor, Marion

1974-01-01

Discusses the impact of world population growth leading to the establishment of the United Nations Fund for Population Activities and to the declaration of 1974 as World Population Year. Previews some of the parameters and interconnecting interests to be considered during this year of intensive population study. (JR)

Population Blocks.

Science.gov (United States)

Smith, Martin H.

1992-01-01

Describes an educational game called "Population Blocks" that is designed to illustrate the concept of exponential growth of the human population and some potential effects of overpopulation. The game material consists of wooden blocks; 18 blocks are painted green (representing land), 7 are painted blue (representing water); and the remaining…

Population dynamics and population control of Galium aparine L.

NARCIS (Netherlands)

Weide, van der R.Y.

1993-01-01

The population biology of Galium aparine L. needs to be better understood, in order to be able to rationalize decisions about the short- and long-term control of this weed species for different cropping practices.

A population dynamics model was developed to

Making a stand: five centuries of population growth in colonizing populations of Pinus ponderosa.

Science.gov (United States)

Lesser, Mark R; Jackson, Stephen T

2012-05-01

The processes underlying the development of new populations are important for understanding how species colonize new territory and form viable long-term populations. Life-history-mediated processes such as Allee effects and dispersal capability may interact with climate variability and site-specific factors to govern population success and failure over extended time frames. We studied four disjunct populations of ponderosa pine in the Bighorn Basin of north-central Wyoming to examine population growth spanning more than five centuries. The study populations are separated from continuous ponderosa pine forest by distances ranging from 15 to >100 km. Strong evidence indicates that the initial colonizing individuals are still present, yielding a nearly complete record of population history. All trees in each population were aged using dendroecological techniques. The populations were all founded between 1530 and 1655 cal yr CE. All show logistic growth patterns, with initial exponential growth followed by a slowing during the mid to late 20th century. Initial population growth was slower than expectations from a logistic regression model at all four populations, but increased during the mid-18th century. Initial lags in population growth may have been due to strong Allee effects. A combination of overcoming Allee effects and a transition to favorable climate conditions may have facilitated a mid-18th century pulse in population growth rate.

Population structure of barley landrace populations and gene-flow with modern varieties.

Directory of Open Access Journals (Sweden)

Elisa Bellucci

Full Text Available Landraces are heterogeneous plant varieties that are reproduced by farmers as populations that are subject to both artificial and natural selection. Landraces are distinguished by farmers due to their specific traits, and different farmers often grow different populations of the same landrace. We used simple sequence repeats (SSRs to analyse 12 barley landrace populations from Sardinia from two collections spanning 10 years. We analysed the population structure, and compared the population diversity of the landraces that were collected at field level (population. We used a representative pool of barley varieties for diversity comparisons and to analyse the effects of gene flow from modern varieties. We found that the Sardinian landraces are a distinct gene pool from those of both two-row and six-row barley varieties. There is also a low, but significant, mean level and population-dependent level of introgression from the modern varieties into the Sardinian landraces. Moreover, we show that the Sardinian landraces have the same level of gene diversity as the representative sample of modern commercial varieties grown in Italy in the last decades, even within population level. Thus, these populations represent crucial sources of germplasm that will be useful for crop improvement and for population genomics studies and association mapping, to identify genes, loci and genome regions responsible for adaptive variations. Our data also suggest that landraces are a source of valuable germplasm for sustainable agriculture in the context of future climate change, and that in-situ conservation strategies based on farmer use can preserve the genetic identity of landraces while allowing adaptation to local environments.

Genetic changeover in Drosophila populations

International Nuclear Information System (INIS)

Wallace, B.

1986-01-01

Three populations of Drosophila melanogaster that were daughter populations of two others with histories of high, continuous radiation exposure [population 5 (irradiated, small population size) gave rise to populations 17 (small) and 18 (large); population 6 (irradiated, large population size) gave rise to population 19 (large)] were maintained for 1 year with no radiation exposure. The frequency with which random combinations of second chromosomes taken from population 19 proved to be lethal changed abruptly after about 8 months, thus revealing the origin of a selectively favored element in that population. (This element may or may not have been the cause of the lethality.) A comparison of the loss of lethals in populations 17 and 18 with a loss that occurred concurrently in the still-irradiated population 5 suggests that a second, selectively favored element had arisen in that population just before populations 17 and 18 were split off. This element was on a nonlethal chromosome. The result in population 5 was the elimination of many lethals from that population, followed by a subsequent increase as mutations occurred in the favored nonlethal chromosome. Populations 17 and 18, with no radiation exposure, underwent a loss of lethals with no subsequent increase. The events described here, as well as others to be described elsewhere, suggest that populations may be subject to episodic periods of rapid gene frequency changes that occur under intense selection pressure. In the instances in which the changeover was revealed by the elimination of preexisting lethals, earlier lethal frequencies were reduced by approximately one-half; the selectively favored elements appear, then, to be favored in the heterozygous--not homozygous--condition

Population catastrophe.

Science.gov (United States)

Ankomah, B

1990-07-01

UNFPA estimates predict that Africa's population will be 1.5 billion by 2025. In the next 10 years the growth rate will be 3%, the highest for any region in human history. Nigeria is expected to have 301 million people in 35 years, making it the 3rd largest country behind India and China. Currently the economies of African countries can not provide enough jobs or food for the current population. What is going to happen in 35 years when the population will almost double? In 1950 Africa only made up 9% of the world population, but by 2025 it will be 18.4% of a global population of 8.4 billion. Currently half of Africa's population is under 15. This means that there is still time to affect change. There is time to convince this generation not to behave like their parents. A 2 child limit per family is an absolute limit if any progress is to be made that will actually have an effect. Many have suggested that the young people should go back to the land instead of living in poverty in the city. However, currently the land distribution is 0.4 hectares/rural person. This figure is going to drop to 0.29/rural person. Migration is simply not the solution. Many rural farmers want to have enough children to ensure that their land is inherited and stays in the family. The same goal can be achieved, with less children. According to the UNFPA 77% of married women who do not want to have more children do not use contraceptives. Only 14% of African women use contraceptives, so that by age 20 50% of African women have had 1 birth. The only way to seriously cut down the birth rate is to get the men of Africa involved in contraceptive use.

Acceptance and Use of Eight Arsenic-Safe Drinking Water Options in Bangladesh

Science.gov (United States)

Inauen, Jennifer; Hossain, Mohammad Mojahidul; Johnston, Richard B.; Mosler, Hans-Joachim

2013-01-01

Arsenic contamination of drinking water is a serious public health threat. In Bangladesh, eight major safe water options provide an alternative to contaminated shallow tubewells: piped water supply, deep tubewells, pond sand filters, community arsenic-removal, household arsenic removal, dug wells, well-sharing, and rainwater harvesting. However, it is uncertain how well these options are accepted and used by the at-risk population. Based on the RANAS model (risk, attitudes, norms, ability, and self-regulation) this study aimed to identify the acceptance and use of available safe water options. Cross-sectional face-to-face interviews were used to survey 1,268 households in Bangladesh in November 2009 (n = 872), and December 2010 (n = 396). The questionnaire assessed water consumption, acceptance factors from the RANAS model, and socioeconomic factors. Although all respondents had access to at least one arsenic-safe drinking water option, only 62.1% of participants were currently using these alternatives. The most regularly used options were household arsenic removal filters (92.9%) and piped water supply (85.6%). However, the former result may be positively biased due to high refusal rates of household filter owners. The least used option was household rainwater harvesting (36.6%). Those who reported not using an arsenic-safe source differed in terms of numerous acceptance factors from those who reported using arsenic-safe sources: non-users were characterized by greater vulnerability; showed less preference for the taste and temperature of alternative sources; found collecting safe water quite time-consuming; had lower levels of social norms, self-efficacy, and coping planning; and demonstrated lower levels of commitment to collecting safe water. Acceptance was particularly high for piped water supplies and deep tubewells, whereas dug wells and well-sharing were the least accepted sources. Intervention strategies were derived from the results in order to

Peru: population and policy.

Science.gov (United States)

Sobrevilla, L A

1987-06-01

Peru's 1985 Population Policy Law states as its second objective that individuals and couples should be well informed and provided with the education and health services that will assist them in making responsible decisions about the number and spacing of their children. Thus, the law establishes a firm basis for IEC programs. With regard to population education, the purpose of the law is to create awareness through all educational channels of the reciprocal influence of population dynamics and socioeconomic development and to promote positive attitudes toward small family size. The law promotes the use of the communications media to educate and inform about population issues. The National Population Council, which coordinates and supervises the IEC activities of public sector agencies, has issued publications and audiovisual materials, conducted meetings with government officials and opinion leaders, and promoted awareness of population policy as a key part of development planning. In 1984, the Council organized the First National Seminar on Communication and Population to review activities, set the basis for intersectoral coordination, unify criteria, and review population policy concepts and language. The Ministry of Health carries out IEC activities as part of its family planning services program. In addition, the Ministry of Education has organized a national population education program that aims to revise school curricula to include a greater emphasis on population dynamics and family life education. The activities of a number of private institutions complement the IEC work public sector organizations.

Estimation of effective population size in continuously distributed populations: There goes the neighborhood

Science.gov (United States)

M. C. Neel; K. McKelvey; N. Ryman; M. W. Lloyd; R. Short Bull; F. W. Allendorf; M. K. Schwartz; R. S. Waples

2013-01-01

Use of genetic methods to estimate effective population size (Ne) is rapidly increasing, but all approaches make simplifying assumptions unlikely to be met in real populations. In particular, all assume a single, unstructured population, and none has been evaluated for use with continuously distributed species. We simulated continuous populations with local mating...

Population Ecology of Caribou Populations without Predators: Southampton and Coats Island Herds

Directory of Open Access Journals (Sweden)

Jean-Pierre Quellet

1996-01-01

Full Text Available This paper is a review of the ecology of two caribou populations inhabiting predator-free northern islands, Coats and Southampton Island. Findings are analyzed in light of the hypothesis that in absence of prédation or high human harvest, food competition results in delayed puberty, reduced calf production, increased winter starvation of caribou and regulates populations at high densities (>2 km-2. Caribou were hunted to extinction on Southampton Island (Northwest Territories, Canada by mid-century. In 1967, 48 caribou were captured on neighbouring Coats Island and released on Southampton Island. Southampton Island is characterized by a high per capita winter food availability in summer and in winter. The population on Southampton Island has been increasing at a rapid rate of growth since re-introduction (Lamba=1.27. Fast population growth was possible because females invested early in reproduction and over winter survival rate was high. The population on Coats Island is also characterized by high per capita food availability in summer but low food availability in winter. The population size has undergone some marked fluctuations, abrupt declines followed by relatively rapid recovery and, contrary to predictions, densities were always less than 1 km-2. Low population densities on Coats Island result primarily from low food availability. This review suggests that in the absence of prédation or high human harvest competition for food regulates caribou population abundance. However, caribou numbers can fluctuate markedly among years because inter-annual variation of weather conditions affects forage accessibility in winter. This review also emphasizes the importance of distinguishing between factors that determine absolute population density and variation in density among years (in our case probably plant production and winter weather conditions which influence forage accessibility from the regulatory factors, processes that stop population

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.

Rapid population growth.

Science.gov (United States)

1972-01-01

At the current rate of population growth, world population by 2000 is expected to reach 7 billion or more, with developing countries accounting for some 5.4 billion, and economically advanced nations accounting for 1.6 billion. 'Population explosion' is the result of falling mortality rates and continuing high birth rates. Many European countries, and Japan, have already completed what is termed as demographic transition, that is, birth rates have fallen to below 20 births per 1000 population, death rates to 10/1000 population, and annual growth rates are 1% or less; annual growth rates for less developed countries ranged from 2 to 3.5%. Less developed countries can be divided into 3 groups: 1) countries with both high birth and death rates; 2) countries with high birth rates and low death rates; and 3) countries with intermediate and declining birth rates and low death rates. Rapid population growth has serious economic consequences. It encourages inequities in income distribution; it limits rate of growth of gross national product by holding down level of savings and capital investments; it exerts pressure on agricultural production and land; and it creates unemployment problems. In addition, the quality of education for increasing number of chidren is adversely affected, as high proportions of children reduce the amount that can be spent for the education of each child out of the educational budget; the cost and adequacy of health and welfare services are affected in a similar way. Other serious consequences of rapid population growth are maternal death and illness, and physical and mental retardation of children of very poor families. It is very urgent that over a billion births be prevented in the next 30 years to reduce annual population growth rate from the current 2% to 1% per year.

Feedback between Population and Evolutionary Dynamics Determines the Fate of Social Microbial Populations

Science.gov (United States)

Sanchez, Alvaro; Gore, Jeff

2013-01-01

The evolutionary spread of cheater strategies can destabilize populations engaging in social cooperative behaviors, thus demonstrating that evolutionary changes can have profound implications for population dynamics. At the same time, the relative fitness of cooperative traits often depends upon population density, thus leading to the potential for bi-directional coupling between population density and the evolution of a cooperative trait. Despite the potential importance of these eco-evolutionary feedback loops in social species, they have not yet been demonstrated experimentally and their ecological implications are poorly understood. Here, we demonstrate the presence of a strong feedback loop between population dynamics and the evolutionary dynamics of a social microbial gene, SUC2, in laboratory yeast populations whose cooperative growth is mediated by the SUC2 gene. We directly visualize eco-evolutionary trajectories of hundreds of populations over 50–100 generations, allowing us to characterize the phase space describing the interplay of evolution and ecology in this system. Small populations collapse despite continual evolution towards increased cooperative allele frequencies; large populations with a sufficient number of cooperators “spiral” to a stable state of coexistence between cooperator and cheater strategies. The presence of cheaters does not significantly affect the equilibrium population density, but it does reduce the resilience of the population as well as its ability to adapt to a rapidly deteriorating environment. Our results demonstrate the potential ecological importance of coupling between evolutionary dynamics and the population dynamics of cooperatively growing organisms, particularly in microbes. Our study suggests that this interaction may need to be considered in order to explain intraspecific variability in cooperative behaviors, and also that this feedback between evolution and ecology can critically affect the demographic fate

feedback between population and evolutionary dynamics determines the fate of social microbial populations.

Directory of Open Access Journals (Sweden)

Alvaro Sanchez

Full Text Available The evolutionary spread of cheater strategies can destabilize populations engaging in social cooperative behaviors, thus demonstrating that evolutionary changes can have profound implications for population dynamics. At the same time, the relative fitness of cooperative traits often depends upon population density, thus leading to the potential for bi-directional coupling between population density and the evolution of a cooperative trait. Despite the potential importance of these eco-evolutionary feedback loops in social species, they have not yet been demonstrated experimentally and their ecological implications are poorly understood. Here, we demonstrate the presence of a strong feedback loop between population dynamics and the evolutionary dynamics of a social microbial gene, SUC2, in laboratory yeast populations whose cooperative growth is mediated by the SUC2 gene. We directly visualize eco-evolutionary trajectories of hundreds of populations over 50-100 generations, allowing us to characterize the phase space describing the interplay of evolution and ecology in this system. Small populations collapse despite continual evolution towards increased cooperative allele frequencies; large populations with a sufficient number of cooperators "spiral" to a stable state of coexistence between cooperator and cheater strategies. The presence of cheaters does not significantly affect the equilibrium population density, but it does reduce the resilience of the population as well as its ability to adapt to a rapidly deteriorating environment. Our results demonstrate the potential ecological importance of coupling between evolutionary dynamics and the population dynamics of cooperatively growing organisms, particularly in microbes. Our study suggests that this interaction may need to be considered in order to explain intraspecific variability in cooperative behaviors, and also that this feedback between evolution and ecology can critically affect the

Transfer of ERR for radiation-related leukemia from Japanese population to Chinese population

International Nuclear Information System (INIS)

Huang Liqiong; Sun Zhijuan; Zhao Yongcheng; Wang Jixian

2011-01-01

Objective: To establish a transfer model for excess relative risk (ERR) for radiation-related leukemia from Japanese population to Chinese population. Methods: Combined ERR of several subtypes of leukemia published in 1994, with the corresponding leukemia baseline incidence rates obtained from Cancer Incidence in Five Continents Vol. Ⅸ (CI5-Ⅸ) for Japanese population and Chinese population, a weighted risk transfer model was employed between an additive model and a multiplicative model, to execute ERR transfer. Results: A range of weighing factors was proposed for risk transfer models: weighing factor was 0.4 for male and 0.3 for female, acute lymphoblastic leukemia, acute myeloid leukemia and chronic myeloid leukemia. The uncertainty for ERR transfer was characterized by lognormal distribution. Conclusions: Based on the difference of baseline incidence rate for subtypes of leukemia between Japanese population and Chinese population, the transfer model and these weighing factors discussed in the present study could be applicable to transfer ERR for radiation-related leukemia from Japanese population to Chinese population. (authors)

The Soviet Union and population: theory, problems, and population policy.

Science.gov (United States)

Di Maio, A J

1980-04-01

Until the important public dialog on 3rd World population issues began in the Soviet Uuion in 1965, ideological limitations and bureaucratic interests prevented policy makers from recognizing the existence of a world of national "population problem." Since then, freer discussions of the Soviet Union's surprising decline in birthrate and labor shortages have led to serious policy questions. Conflicting policy goals, however, have resulted in only modest pronatalist policies. The Soviet population problem is a result of interregional disparities in population growth rates between the highly urbanized Soviet European populations with low birth rates and the least urbanized Central Asians with dramatically higher birth rates. As a result, these essentially Muslim people will provide the only major increases in labor resources and an increasing percentage of Soviet armed forces recruits. Policy planners are thus faced with difficult options. Current policies stressing technological transfers from the west and greater labor productivity, however, are unlikely to solve further labor shortages and regional imbalances. Ultimately, nonEuropana regions will be in an improved bargaining position for more favorable nationwide economic policies and for a greater role in policy planning.

Population success.

Science.gov (United States)

1982-01-01

"The commitment to population programs is now widespread," says Rafael Salas, Executive Director of the UNFPA, in its report "State of World Population." About 80% of the total population of the developing world live in countries which consider their fertility levels too high and would like them reduced. An important impetus came from the World Conference of 1974. The Plan of Action from the conference projected population growth rates in developing countries of 2.0% by 1985. Today it looks as though this projection will be realized. While in 1969, for example, only 26 developing countries had programs aimed at lowering or maintaining fertility levels, by 1980 there were 59. The International Population Conference, recently announced by the UN for 1984, will, it is hoped, help sustain that momentum. Cuba is the country which has shown the greatest decline in birth rate so far. The birth rate fell 47% between 1965-1970 and 1975-1980. Next came China with a 34% decline in the same period. After these came a group of countries--each with populations of over 10 million--with declines of between 15 and 25%: Chile, Colombia, India, Indonesia, the Republic of Korea, Malaysia and Thailand. Though birth rates have been dropping significantly the decline in mortality rates over recent years has been less than was hoped for. The 1974 conference set 74 years as the target for the world's average expectation of life, to be reached by the year 2000. But the UN now predicts that the developing countries will have only reached 63 or 64 years by then. High infant and child mortality rates, particularly in Africa, are among the major causes. The report identifies the status of women as an important determinant of family size. Evidence from the UNFPA-sponsored World Fertility Survey shows that in general the fertility of women decreases as their income increases. It also indicates that women who have been educated and who work outside the home are likely to have smaller families

AIDS and population "control".

Science.gov (United States)

Piel, G

1994-02-01

Many people believe that the AIDS pandemic will end the population explosion, especially in Africa, where population growth is very high and poverty reigns. Africans make up 10 million of all 15 million HIV- infected persons worldwide. Yet, the proposition that AIDS will sole population explosion does not stand up to reason. About 200 million people in Africa will be HIV infected by 2010, but the loss of 200 million people would not slow population growth. The 14th century's Black Death killed more than 50% of the European population, but by 1750 Europe had reached the population size it would have reached without the Black Death. The 200 million people who died violent deaths between the start and end of the two World Wars did not stop world population growth from peaking in 1970 at about 2%. When Malthus made his prediction that human population would crash, the industrial revolution had already helped production outrun population growth. Today all industrial countries are either at or near zero population growth and have completed the demographic transition (from near zero growth in 1600 with high births and death rates and a 25-year life expectancy, to near zero growth in 1990s at low death and birth rates with a 75-year life expectancy). Mass education, sanitation, primary medicine, and the green revolution have already reduced death rates and increased life expectancy in developing countries. Thus, they have entered the first phase of the demographic transition. Some developing countries are in the second phase; birth rate decline For example, in India and China, fertility has fallen from 6 to 4 in India and is at 2.3 in China. The AIDS pandemic is a diversion of physical and human resources from helping developing countries pass through the demographic transition more quickly to achieve sustainable development. This delay is likely to effect a larger maximum population. The industrial revolution has shifted the key to stopping population growth the people

Final Environmental Impact Statement Evolved Expendable Launch Vehicle Program

Science.gov (United States)

1998-04-01

including increased blood pressure and higher levels of available glucose and corticosteroids in the bloodstream. Continued disturbances and prolonged...treefrogs. Besides the common American alligator , reptiles observed include the Florida box turtle, the gopher tortoise, the Florida softshell, the...star Remirea maritima - E Reptiles and Amphibians Gopher frog Rana capito C SSC American alligator Alligator mississippiensis T(S/A) SSC Eastern Indigo

Is premeiotic genome elimination an exclusive mechanism for hemiclonal reproduction in hybrid males of the genus Pelophylax?

Czech Academy of Sciences Publication Activity Database

Doležálková, Marie; Sember, Alexandr; Marec, František; Ráb, Petr; Plötner, J.; Choleva, Lukáš

2016-01-01

Roč. 17, č. 100 (2016) ISSN 1471-2156 R&D Projects: GA ČR GJ15-19947Y; GA ČR(CZ) GA14-22765S Institutional support: RVO:67985904 ; RVO:60077344 Keywords : hybridogenesis * asexual propagation * hemiclone * meiotic cycle * genomic in situ hybridization * Rana Subject RIV: EG - Zoology; EB - Genetics ; Molecular Biology (BC-A) Impact factor: 2.266, year: 2016

Diversity of Poissonian populations.

Science.gov (United States)

Eliazar, Iddo I; Sokolov, Igor M

2010-01-01

Populations represented by collections of points scattered randomly on the real line are ubiquitous in science and engineering. The statistical modeling of such populations leads naturally to Poissonian populations-Poisson processes on the real line with a distinguished maximal point. Poissonian populations are infinite objects underlying key issues in statistical physics, probability theory, and random fractals. Due to their infiniteness, measuring the diversity of Poissonian populations depends on the lower-bound cut-off applied. This research characterizes the classes of Poissonian populations whose diversities are invariant with respect to the cut-off level applied and establishes an elemental connection between these classes and extreme-value theory. The measures of diversity considered are variance and dispersion, Simpson's index and inverse participation ratio, Shannon's entropy and Rényi's entropy, and Gini's index.

Are invasive populations characterized by a broader diet than native populations?

Directory of Open Access Journals (Sweden)

Julien Courant

2017-05-01

Full Text Available Background Invasive species are among the most significant threats to biodiversity. The diet of invasive animal populations is a crucial factor that must be considered in the context of biological invasions. A broad dietary spectrum is a frequently cited characteristic of invasive species, allowing them to thrive in a wide range of environments. Therefore, empirical studies comparing diet in invasive and native populations are necessary to understand dietary requirements, dietary flexibility, and the associated impacts of invasive species. Methods In this study, we compared the diet of populations of the African clawed frog, Xenopus laevis in its native range, with several areas where it has become invasive. Each prey category detected in stomach contents was assigned to an ecological category, allowing a comparison of the diversity of ecological traits among the prey items in the diet of native and introduced populations. The comparison of diets was also performed using evenness as a niche breadth index on all sampled populations, and electivity as a prey selection index for three out of the six sampled populations. Results Our results showed that diet breadth could be either narrow or broad in invasive populations. According to diet and prey availability, zooplankton was strongly preferred in most cases. In lotic environments, zooplankton was replaced by benthic preys, such as ephemeropteran larvae. Discussion The relative proportions of prey with different ecological traits, and dietary variability within and between areas of occurrence, suggest that X. laevis is a generalist predator in both native and invasive populations. Shifts in the realized trophic niche are observed, and appear related to resource availability. Xenopus laevis may strongly impact aquatic ecosystems because of its near complete aquatic lifestyle and its significant consumption of key taxa for the trophic relationships in ponds.

Population Policy and the Changing Distribution of the U.S. Population--Implications for Teaching Population Geography.

Science.gov (United States)

Gober, Patricia

The role of migration and of federal policy in population redistribution should be a central focus in population geography education. Although migration to the Sunbelt and the West has been a pattern since the 1950s, a significant trend has been noted only since the 1970s, when the birth rate dropped so much that natural increase could not…

Alternative population futures.

Science.gov (United States)

1980-01-01

The Philippines is now passing through a late demographic transitional period in which the death rate declines while the birth rate remains at a relatively high level; the population of young people under 15 rises to about 45% of the population while proportions of people of working age and old people decline. In 1970, 4 of the Philippine's 12 regions had a birth rate exceeding 40/1000; life expectancy at birth in these regions ranged from 57-64 years and population growth rates ranged from 2.6-4.2% annually. Also in 1970 40-49% of all 12 regional populations were young (under 15) and only 2-5% were old. In this transitional period there are a greater number of children in each household and thus heavier social and economic burdens occur; also the burden of youth dependency increases by more than 1/3. In the modern population structure, family burdens diminish as the average number of children surviving to age 20 becomes identical with the number of children born and great improvements in the quality of life are allowed. Population projections are based on the following assumptions: 1) decrease in mortality, either rapid or slow, 2) increase in age at marriage, 3) decline in fertility will remain at 0.7% annually, and 4) migration trends will stay the same as during the 1960-75 period. Total population is expected to reach 83.8 million by 2000, a 98% increase from 1975; a low estimate, assuming lower fertility and nuptiality, is 64.1 million, a 52% increase from 1975. The urban population will more than double its size by the year 2000 and rural population will grow from 22-65% with the fastest urbanizing regions being the Central and Southern Luzon. From 1975-2000 a 3-fold increase is expected in the number of families in Metro Manila. By 2000 a national labor force of 27.5 million is expected, more than double the 1970 level, with late entry into the labor force and declines in participation by elderly males. The various regions will see lower economic activity

A POPULATION MEMETICS APPROACH TO CULTURAL EVOLUTION IN CHAFFINCH SONG: DIFFERENTIATION AMONG POPULATIONS.

Science.gov (United States)

Lynch, Alejandro; Baker, Allan J

1994-04-01

We investigated cultural evolution in populations of common chaffinches (Fringilla coelebs) in the Atlantic islands (Azores, Madeira, and Canaries) and neighboring continental regions (Morocco and Iberia) by employing a population-memetic approach. To quantify differentiation, we used the concept of a song meme, defined as a single syllable or a series of linked syllables capable of being transmitted. The levels of cultural differentiation are higher among the Canaries populations than among the Azorean ones, even though the islands are on average closer to each other geographically. This is likely the result of reduced levels of migration, lower population sizes, and bottlenecks (possibly during the colonization of these populations) in the Canaries; all these factors produce a smaller effective population size and therefore accentuate the effects of differentiation by random drift. Significant levels of among-population differentiation in the Azores, in spite of substantial levels of migration, attest to the differentiating effects of high mutation rates of memes, which allow the accumulation of new mutants in different populations before migration can disperse them throughout the entire region. © 1994 The Society for the Study of Evolution.

The Growth of Older Inmate Populations: How Population Aging Explains Rising Age at Admission.

Science.gov (United States)

Luallen, Jeremy; Cutler, Christopher

2017-09-01

Older inmates are the fastest growing segment of the prison population; however, the reasons for this are not well understood. One explanation is that the general population is aging, driving prison age distributions to change. For this article, we study the role of population aging in prison growth by investigating how the baby boom phenomenon of post-World War II has contributed to the growth of older inmate populations. We identify the impact of population aging using simulation methods that explain prison growth as the combination of criminal justice processes. Overall, we find evidence that population aging has played a significant role in explaining the growth of older inmate populations, in particular among inmates aged between 50 and 64 years, contributing to as much as half of the observed increase in these groups since 2000. This finding stands in contrast to the notion that population aging has little explanatory power in describing the growth of prison populations and implies that older inmate groups are more sensitive to compositional changes in the general population. We argue that prediction-based modeling of prison growth should more seriously consider the impacts and consequences of demographic shifts among older prisoner populations. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Multi-population Genomic Relationships for Estimating Current Genetic Variances Within and Genetic Correlations Between Populations.

Science.gov (United States)

Wientjes, Yvonne C J; Bijma, Piter; Vandenplas, Jérémie; Calus, Mario P L

2017-10-01

Different methods are available to calculate multi-population genomic relationship matrices. Since those matrices differ in base population, it is anticipated that the method used to calculate genomic relationships affects the estimate of genetic variances, covariances, and correlations. The aim of this article is to define the multi-population genomic relationship matrix to estimate current genetic variances within and genetic correlations between populations. The genomic relationship matrix containing two populations consists of four blocks, one block for population 1, one block for population 2, and two blocks for relationships between the populations. It is known, based on literature, that by using current allele frequencies to calculate genomic relationships within a population, current genetic variances are estimated. In this article, we theoretically derived the properties of the genomic relationship matrix to estimate genetic correlations between populations and validated it using simulations. When the scaling factor of across-population genomic relationships is equal to the product of the square roots of the scaling factors for within-population genomic relationships, the genetic correlation is estimated unbiasedly even though estimated genetic variances do not necessarily refer to the current population. When this property is not met, the correlation based on estimated variances should be multiplied by a correction factor based on the scaling factors. In this study, we present a genomic relationship matrix which directly estimates current genetic variances as well as genetic correlations between populations. Copyright © 2017 by the Genetics Society of America.

Population and development.

Science.gov (United States)

1987-03-01

The Economic and Social Commission for Asia and the Pacific (ESCAP) recently organized a workshop to develop an analytical framework for population research and development planning. The workshop goal was to enable study directors to review and discuss research methodology and guidelines for a series of country studies to be undertaken as part of a large project devoted to integrating population and development. The overall project objective is to provide individual national entities with current and scientifically sound descriptions, analyses, and interpretations of significant population and development trends and their interrelationships along with assessments of the implications of such trends and relationships for the formulation and improvement of public policy. 1 reason for the limited progress in the integration of population and development planning is the lack of useful and applicable scientific information for responsible planners as well as a lack of analytical frameworks. If the results of the research are to be made useful for decisionmaking purposes, processing of the information is required. The need exists for current critical analysis and synthesis of available information at the country level on significant population and development trends and their interrelationships and an assessment of their implications for the formulation and improvement of public policy and programs. In regard to an analytical framework, much work has been done in the areas of population development interrelationships and their modelling. Bangladesh, Nepal, the Philippines, and Thailand are the countries which have been selected for investigation for the ESCAP project. The comparative analysis that is to be conducted will facilitate understanding of current population development research activities and the future needs of these countries.

Setting population targets for mammals using body mass as a predictor of population persistence.

Science.gov (United States)

Hilbers, Jelle P; Santini, Luca; Visconti, Piero; Schipper, Aafke M; Pinto, Cecilia; Rondinini, Carlo; Huijbregts, Mark A J

2017-04-01

Conservation planning and biodiversity assessments need quantitative targets to optimize planning options and assess the adequacy of current species protection. However, targets aiming at persistence require population-specific data, which limit their use in favor of fixed and nonspecific targets, likely leading to unequal distribution of conservation efforts among species. We devised a method to derive equitable population targets; that is, quantitative targets of population size that ensure equal probabilities of persistence across a set of species and that can be easily inferred from species-specific traits. In our method, we used models of population dynamics across a range of life-history traits related to species' body mass to estimate minimum viable population targets. We applied our method to a range of body masses of mammals, from 2 g to 3825 kg. The minimum viable population targets decreased asymptotically with increasing body mass and were on the same order of magnitude as minimum viable population estimates from species- and context-specific studies. Our approach provides a compromise between pragmatic, nonspecific population targets and detailed context-specific estimates of population viability for which only limited data are available. It enables a first estimation of species-specific population targets based on a readily available trait and thus allows setting equitable targets for population persistence in large-scale and multispecies conservation assessments and planning. © 2016 The Authors. Conservation Biology published by Wiley Periodicals, Inc. on behalf of Society for Conservation Biology.

[Several problems concerning population investment].

Science.gov (United States)

Liu, Z

1982-07-29

Population investment is a major topic in the studies of population and economic relations. In this particular area, numerous theoretical and practical problems are still in need of solution. Concerning the problem of population concept, there are three different approaches: (1) to determine the definition of population investment from the relationship between the population growth and the capital from national income used for investment, including investment in the newly increased population and investment in the entire population; (2) to explain population investment from the economic viewpoint that people are producers; and (3) to explain population investment from the expense needed to change a simple labor force to a skillful labor force. The expenses include educational costs, maintanance spending, wages needed to compensate workers in labor, costs for workers to master and learn modern scientific techniques to be used for production, and the costs of keeping a young labor force in the next generation.

Population Estimates and Projections: Projections of the Population of the United States, 1975 to 2050. Current Population Reports, Series P-25, No. 601.

Science.gov (United States)

Gibson, Campbell; Wetrogan, Signe

This report presents population projections of the United States by age, sex, and the components of population changes, births, deaths, and net immigration. These projections are shown annually by race--white and black--from 1975 to 2000 and in less detail for the total population from 2000 to 2050. In 1974, the population of the United States,…

Effects of atrazine on embryos, larvae, and adults of anuran amphibians.

Science.gov (United States)

Allran, J W; Karasov, W H

2001-04-01

We examined the effects of atrazine (0-20 mg/L) on embryos, larvae, and adult anuran amphibian species in the laboratory. Atrazine treatments did not affect hatchability of embryos or 96-h posthatch mortality of larvae of Rana pipiens, Rana sylvatica, or Bufo americanus. Furthermore, atrazine had no effect on swimming speed (measured for R. pipiens only). However, there was a dose-dependent increase in deformed larvae of all three species with increasing atrazine concentration. In adult R. pipiens, atrazine increased buccal and thoracic ventilation, indicating respiratory distress. However, because atrazine had no affect on hemoglobin, this respiratory distress was probably not indicative of reduced oxygen-carrying capacity of the blood. Frogs exposed to the highest atrazine concentration stopped eating immediately after treatment began and did not eat during the 14-d experiment. However, no decreases in mass were measured even for frogs that were not eating, probably because of compensatory fluid gain from edema. Atrazine concentrations found to be deleterious to amphibian embryos and adults are considerably higher than concentrations currently found in surface waters in North America. Therefore, direct toxicity of atrazine is probably not a significant factor in recent amphibian declines.

Morphological and molecular differentiation of two new species of Pseudoacanthocephalus Petrochenko, 1958 (Acanthocephala: Echinorhynchidae) from amphibians and reptiles in the Philippines, with identification key for the genus.

Science.gov (United States)

Tkach, Vasyl V; Lisitsyna, Olga I; Crossley, Janna L; Binh, Tran Thi; Bush, Sarah E

2013-05-01

The genus Pseudoacanthocephalus Petrochenko, 1958 currently includes 14 species of acanthocephalans parasitic in amphibians and reptiles worldwide. This work describes two new species of Pseudoacanthocephalus from amphibians and reptiles collected in several localities on Luzon Island, Philippines. Pseudoacanthocephalus nickoli n. sp. was found in two species of frogs, Rana luzonensis Boulenger and Rana similis (Günther), and Pseudoacanthocephalus smalesi n. sp. was found in a scincid lizard, Sphenomorphus abdictus Brown & Alcala. Differential diagnoses of the two new species of Pseudoacanthocephalus from their congeners are provided. Comparative analysis of nuclear ribosomal rRNA sequences encompassing the 3' end of 18S nuclear rDNA gene, internal transcribed spacer region (ITS1+5.8S+ITS2), and 5' end of the 28S gene strongly corroborated the morphological evidence and demonstrated significant differences between the two new species as well as between these species and closely related species from continental China and Vietnam. No intraspecific sequence variability was detected among different individuals representing each of the examined species. This is the first report of Pseudoacanthocephalus in the Philippines. A key to known species of Pseudoacanthocephalus is provided.

Modeling Exponential Population Growth

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McCormick, Bonnie

2009-01-01

The concept of population growth patterns is a key component of understanding evolution by natural selection and population dynamics in ecosystems. The National Science Education Standards (NSES) include standards related to population growth in sections on biological evolution, interdependence of organisms, and science in personal and social…

Population and development.

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Ramana, D V

1977-10-01

Between 1950-1976 world population increased by 1.5 billion and was accompanied by unprecedented levels of poverty, unemployment, and inequality. Additional problems associated with this marked population increase are related to food supply, human resource development, the infrastructure component of human organization - housing, water supply, and lighting - and environment. Consequently, it becomes apparent that for purposes of development over the next generation or so, it is the absolute population size and its built-in momentum for increase that becomes relevant rather than the declaration of the population growth rate. Necessary is a model of development in which both consumption and investment expenditures are planned in such a way as to yield the highest possible social rate of return. Investment and consumption planning is required as instrumentalities for making income accrue directly to as great a section of the poor as possible. Simultaneously, the following action should be initiated for decreasing the fertility rate to replacement levels: provision of family planning services, education of all social groups regarding the effects of large families and rapid population growth, provision of alternative careers to motherhood, equal rights for women, and reshaping economic and social policies to encourage small families.

Plasmodium vivax populations revisited: mitochondrial genomes of temperate strains in Asia suggest ancient population expansion

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Miao Miao

2012-02-01

Full Text Available Abstract Background Plasmodium vivax is the most widely distributed human malaria parasite outside of Africa, and its range extends well into the temperate zones. Previous studies provided evidence for vivax population differentiation, but temperate vivax parasites were not well represented in these analyses. Here we address this deficit by using complete mitochondrial (mt genome sequences to elucidate the broad genetic diversity and population structure of P. vivax from temperate regions in East and Southeast Asia. Results From the complete mtDNA sequences of 99 clinical samples collected in China, Myanmar and Korea, a total of 30 different haplotypes were identified from 26 polymorphic sites. Significant differentiation between different East and Southeast Asian parasite populations was observed except for the comparison between populations from Korea and southern China. Haplotype patterns and structure diversity analysis showed coexistence of two different groups in East Asia, which were genetically related to the Southeast Asian population and Myanmar population, respectively. The demographic history of P. vivax, examined using neutrality tests and mismatch distribution analyses, revealed population expansion events across the entire P. vivax range and the Myanmar population. Bayesian skyline analysis further supported the occurrence of ancient P. vivax population expansion. Conclusions This study provided further resolution of the population structure and evolution of P. vivax, especially in temperate/warm-temperate endemic areas of Asia. The results revealed divergence of the P. vivax populations in temperate regions of China and Korea from other populations. Multiple analyses confirmed ancient population expansion of this parasite. The extensive genetic diversity of the P. vivax populations is consistent with phenotypic plasticity of the parasites, which has implications for malaria control.

Life history, population viability, and the potential for local adaptation in isolated trout populations

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K.J. Carim

2017-04-01

Full Text Available Habitat loss and fragmentation have caused population decline across taxa through impacts on life history diversity, dispersal patterns, and gene flow. Yet, intentional isolation of native fish populations is a frequently used management strategy to protect against negative interactions with invasive fish species. We evaluated the population viability and genetic diversity of 12 isolated populations of Oncorhynchus clarkii lewisi located on the Flathead Indian Reservation in Montana, USA. Length-structured integral projection models (IPMs were used to project population growth rate (lambda and its sensitivity to underlying vital rates and parameters. We examined relationships between lambda, genetic diversity, and habitat size and quality. Lambda ranged from 0.68 to 1.1 with 10 of 12 populations projected to be in decline. A sensitivity analysis of lambda with respect to projection matrix elements indicated that lambda was generally sensitive to changes in early life history stages (survival/growth, but patterns differed among populations. Another sensitivity analysis with respect to underlying model parameters showed highly consistent pattern across populations, with lambda being most sensitive to the slope of probability of maturity (estimated from published literature, generally followed by adult survival, and the slope of somatic growth rate (directly measured from each population. Lambda was not correlated with genetic diversity. For populations residing in small isolated streams (≤5 km of occupied habitat, lambda significantly increased with base flow discharge (r2=0.50, p<0.02. Our results highlight the potential importance of local adaptation for persistence of small, isolated populations. Specifically we saw evidence for higher probability of maturity at smaller sizes in the smallest, coldest isolated systems, increasing probability of persistence for these populations. Climate change threatens to further fragment populations of

America's Families and Living Arrangements: 2003. Population Characteristics. Current Population Reports. P20-553

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Fields, Jason

2004-01-01

The data in this report is from the Annual Social and Economic Supplement (ASEC) to the 2003 Current Population Survey (CPS). The population represented (the population universe) in the ASEC is the civilian non institutionalized population living in the United States. Members of the Armed Forces living off post or with their families on post are…

Population genetic structure in natural and reintroduced beaver (Castor fiber populations in Central Europe

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Kautenburger, R.

2008-12-01

Full Text Available Castor fiber Linnaeus, 1758 is the only indigenous species of the genus Castor in Europe and Asia. Due to extensive hunting until the beginning of the 20th century, the distribution of the formerly widespread Eurasian beaver was dramatically reduced. Only a few populations remained and these were in isolated locations, such as the region of the German Elbe River. The loss of genetic diversity in small or captive populations throughgenetic drift and inbreeding is a severe conservation problem. However, the reintroduction of beaver populations from several regions in Europe has shown high viability and populations today are growing fast. In the present study we analysed the population genetic structure of a natural and two reintroduced beaver populations in Germany and Austria. Furthermore, we studied the genetic differentiation between two beaver species, C. fiber and the American beaver (C. canadensis, using RAPD (Random Amplified Polymorphic DNA as a genetic marker. The reintroduced beaver populations of different origins and the autochthonous population of the Elbe River showed a similar low genetic heterogeneity. There was an overall high genetic similarity in the species C. fiber, and no evidence was found for a clear subspecific structure in the populations studied.

Populations in clonal plants

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Jussi Tammisola

1986-12-01

Full Text Available Population phenomena in higher plants are reviewed critically, particularly in relation to clonality. An array of concepts used in the field are discussed. In contrast to animals, higher plants are modular in structure. Plant populations show hierarchy at two levels: ramets and genets. In addition, their demography is far more complicated, since even the direction of development of a ramet may change by rejuvenation. Therefore, formulae concerning animal populations often require modification for plants. Furthermore, at the zygotic stage, higher plants are generally less mobile than animals. Accordingly, their population processes tend to be more local. Most populations of plants have a genetic structure: alleles and genotypes are spatially aggregated. Due to the short-ranged foraging behaviour of pollinators, genetically non-random pollination prevails. A generalized formula for parent-offspring dispersal variance is derived. It is used to analyze the effect of clonality on genetic patchiness in populations. In self-compatible species, an increase in clonality will tend to increase the degree of patchiness, while in self-incompatible species a decrease may result. Examples of population structure studies in different species are presented. A considerable degree of genetic variation appears to be found also in the populations of species with a strong allocation of resources to clonal growth or apomictic seed production. Some consequences of clonality are considered from the point of view of genetic conservation and plant breeding.

Analysis of Population Substructure in Two Sympatric Populations of Gran Chaco, Argentina

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Sevini, Federica; Yao, Daniele Yang; Lomartire, Laura; Barbieri, Annalaura; Vianello, Dario; Ferri, Gianmarco; Moretti, Edgardo; Dasso, Maria Cristina; Garagnani, Paolo; Pettener, Davide; Franceschi, Claudio; Luiselli, Donata; Franceschi, Zelda Alice

2013-01-01

Sub-population structure and intricate kinship dynamics might introduce biases in molecular anthropology studies and could invalidate the efforts to understand diseases in highly admixed populations. In order to clarify the previously observed distribution pattern and morbidity of Chagas disease in Gran Chaco, Argentina, we studied two populations (Wichí and Criollos) recruited following an innovative bio-cultural model considering their complex cultural interactions. By reconstructing the genetic background and the structure of these two culturally different populations, the pattern of admixture, the correspondence between genealogical and genetic relationships, this integrated perspective had the power to validate data and to link the gap usually relying on a singular discipline. Although Wichí and Criollos share the same area, these sympatric populations are differentiated from the genetic point of view as revealed by Non Recombinant Y Chromosome genotyping resulting in significantly high Fst values and in a lower genetic variability in the Wichí population. Surprisingly, the Amerindian and the European components emerged with comparable amounts (20%) among Criollos and Wichí respectively. The detailed analysis of mitochondrial DNA showed that the two populations have as much as 87% of private haplotypes. Moreover, from the maternal perspective, despite a common Amerindian origin, an Andean and an Amazonian component emerged in Criollos and in Wichí respectively. Our approach allowed us to highlight that quite frequently there is a discrepancy between self-reported and genetic kinship. Indeed, if self-reported identity and kinship are usually utilized in population genetics as a reliable proxy for genetic identity and parental relationship, in our model populations appear to be the result not only and not simply of the genetic background but also of complex cultural determinants. This integrated approach paves the way to a rigorous reconstruction of

NASA Orbital Debris Baseline Populations

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Krisko, Paula H.; Vavrin, A. B.

2013-01-01

The NASA Orbital Debris Program Office has created high fidelity populations of the debris environment. The populations include objects of 1 cm and larger in Low Earth Orbit through Geosynchronous Transfer Orbit. They were designed for the purpose of assisting debris researchers and sensor developers in planning and testing. This environment is derived directly from the newest ORDEM model populations which include a background derived from LEGEND, as well as specific events such as the Chinese ASAT test, the Iridium 33/Cosmos 2251 accidental collision, the RORSAT sodium-potassium droplet releases, and other miscellaneous events. It is the most realistic ODPO debris population to date. In this paper we present the populations in chart form. We describe derivations of the background population and the specific populations added on. We validate our 1 cm and larger Low Earth Orbit population against SSN, Haystack, and HAX radar measurements.

Having quality population.

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Ramos, F V

1993-06-01

This speech was delivered during Population and Development Week in the Philippines. Attention was drawn to population statistics: an annual growth rate of 2.3%, density of 202 persons/sq km, and an expected population of 75 million by the year 2000. Coupled with rapid population growth is the uneven distribution of wealth: the top 20% have over 50% of the total income and the lowest 20% have only 5% of the income. In such a social situation, it is women and children who are the most vulnerable. In cities, unemployment is high due to population growth and the migration of the rural poor. The rural poor living in areas of declining resources also move onto marginal uplands, which adds pressure to the already fragile ecology. Everyone must accept that the nation's problems are due to overpopulation. The government's development plans aim for sustainable growth, poverty alleviation, reduction in equality, generation of job opportunities, and achievement of social justice. People in government are determined to lead the Philippines toward a higher standard comparable with other dynamic Asian neighbors. The strategy is empowerment of the people. THe value is in the welfare of individuals and their families and the welfare of the nation. Couples have the right to manage their family size voluntarily and responsibly. The government's role is to provide adequate information on family planning in accordance with individual's religious convictions. Policies will also be directed to improved access to quality education, child survival, and maternal health, employment opportunities, and access and control over resources for people. There must be fuller participation of women in development. Support for the government's population program is sought from government officials, the private sector, and nongovernmental organizations. All provincial governors, city and municipal mayors, and all local executives will be directed to formulate population plans and to provide family

Tobacco addiction in the psychiatric population and in the general population

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Renata Marques de Oliveira

2017-12-01

Full Text Available ABSTRACT Objective: To estimate the degree of tobacco addiction and identify independently associated factors by comparing the psychiatric population of secondary and tertiary care with the general population of the primary healthcare network. Method: This is a cross-sectional epidemiological study, conducted in a municipality of São Paulo, with 134 smokers of a Mental Health Outpatient Unit (MHOU, a Psychiatric Hospital (PH, and a Primary Healthcare Unit (PHU. Data were collected by means of individual interviews, recorded on a mobile device. Data were statistically processed using Stata/12 Results: Of the 134 participants, 54.5% were women. While 49.1% of the psychiatric population (MHOU/PH had medium/high nicotine addiction, 58.3% of smokers of the general population had very low/low dependency. The Poisson regression model indicated a higher prevalence of smokers with high dependence among men (PR = 1.41, people aged 49 years or less (15 - 29 years, PR = 4.06, 30 - 39 PR = 2.96 years, 40 - 49 years PR = 1.84, with severe mental disorders (PR = 3.05, with anxiety disorders/other (PR = 3.98, and with high suicide risk (PR = 1.55. Conclusion: Nicotine dependence was greater in the psychiatric population than in the general population. The independent factors associated with severe dependence were sex, age group, diagnosis, and current risk of suicide. These results trigger reflection among nurses on the need to focus more attention on a neglected subject in mental health services.

Controlling Population with Pollution

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Browne, Joseph

2010-01-01

Population models are often discussed in algebra, calculus, and differential equations courses. In this article we will use the human population of the world as our application. After quick looks at two common models we'll investigate more deeply a model which incorporates the negative effect that accumulated pollution may have on population.