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Sample records for rana rugosa molecular

  1. 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.

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

    Science.gov (United States)

    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.

  3. 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...

  4. 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 ...

  5. 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.

  6. [Structural organization of 5S ribosomal DNA of Rosa rugosa].

    Science.gov (United States)

    Tynkevych, Iu O; Volkov, R A

    2014-01-01

    In order to clarify molecular organization of the genomic region encoding 5S rRNA in diploid species Rosa rugosa several 5S rDNA repeated units were cloned and sequenced. Analysis of the obtained sequences revealed that only one length variant of 5S rDNA repeated units, which contains intact promoter elements in the intergenic spacer region (IGS) and appears to be transcriptionally active is present in the genome. Additionally, a limited number of 5S rDNA pseudogenes lacking a portion of coding sequence and the complete IGS was detected. A high level of sequence similarity (from 93.7 to 97.5%) between the IGS of major 5S rDNA variants of East Asian R. rugosa and North American R. nitida was found indicating comparatively recent divergence of these species.

  7. analysis of genetic diversity and relationship of Chinese Rosa rugosa

    African Journals Online (AJOL)

    Administrator

    2011-05-30

    May 30, 2011 ... Rosa rugosa is a deciduous shrub of the genus Rosa, having prickly stems ... eastern Shandong province and Tumen River estuary ..... Smithsonian Institution, Washington DC, USA. Sokolov SY ... Distribution of trees and.

  8. 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...

  9. Cloning and expression analysis of transcription factor RrTTG1 related to prickle development in rose (Rosa Rugosa

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    Feng Li-Guo

    2015-01-01

    Full Text Available A prickle is an acuminate protuberance formed by the deformation of plant trichomes together with a few cortical cells. It is a type of multicellular eglandular trichome with special morphology, which originates from the phloem but is not connected to the xylem. Rosa rugosa is an important ornamental/commercial plant and an important raw material in the food and perfume industries. However, the firm prickles on its stems are inconvenient to field management, the harvesting of flowers and garden management. The TTG1 transcription factor related to the development of prickle was isolated from R. rugosa in the present study. Its expression patterns in different tissues and varieties were analyzed. Results showed the expression level of the RrTTG1 gene was highest in the leaves, followed by the stems, but was lower in the pericarps and petals. Moreover, the higher expression level of the RrTTG1 gene in all tissues of the ‘Ciguo rose’, as compared with that of the ‘Weihai wild rose’, follows the results of field morphological observation. Therefore, the RrTTG1 transcription factor is likely to regulate the development of rose prickles. This study allows for further discussion on the molecular mechanisms of prickle formation and development in R. rugosa and provides a molecular basis for the cultivation of roses with fewer or no prickles via genetic engineering.

  10. Profile of the Phenolic Compounds of Rosa rugosa Petals

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    Andrzej Cendrowski

    2017-01-01

    Full Text Available Rosa rugosa petals are a rich source of phenolic compounds, which determined their antioxidant properties. The aim of this study was to determine the polyphenolic composition of not processed petals of Rosa rugosa collected from the commodity crops and to determine the variability of the contained therein polyphenols between harvesting seasons. Twenty polyphenols were identified by UPLC-ESI-MS. The main fraction of polyphenols was ellagitannins, which are 69 to 74% of the total polyphenols of the petals. In the petals of Rosa rugosa, four anthocyanins have been identified: cyanidin 3,5-di-O-glucoside, peonidin 3-O-sophoroside, peonidin 3,5-di-O-glucoside, and peonidin 3-O-glucoside, of which the predominant peonidin 3,5-di-O-glucoside represented approx. 85% of all the determined anthocyanin compounds. It was found that the petals of Rosa rugosa are a valuable source of bioactive compounds and can be considered as a healthy valuable resource.

  11. Microplate Bioassay for Determining Substrate Selectivity of "Candida rugosa" Lipase

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    Wang, Shi-zhen; Fang, Bai-shan

    2012-01-01

    Substrate selectivity of "Candida rugosa" lipase was tested using "p"-nitrophenyl esters of increasing chain length (C[subscript 1], C[subscript 7], C[subscript 15]) using the high-throughput screening method. A fast and easy 96-well microplate bioassay was developed to help students learn and practice biotechnological specificity screen. The…

  12. Vojnovskytesidae - a new family of Mississippian Rugosa (Anthozoa)

    Science.gov (United States)

    Fedorowski, Jerzy; Kullmann, Jürgen

    2013-12-01

    Fedorowski, J. and Kullmann, J. 2013. Vojnovskytesidae - a new family of Mississippian Rugosa (Anthozoa). Acta Geologica Polonica, 63(4), 657-679. Warszawa. Two new species of the genus Vojnovskytes Fedorowski, 2009, namely V. marcinowskii and V. arcuatus, and a new genus, Vojnimitor, based on the new species V. proiectus, all from Mississippian strata of northern Spain, are described. Vojnovskytes variabilis (Vojnovsky-Krieger, 1934), the type species for the genus from the lowermost Visean strata of southern Urals, also is discussed and illustrated. Characters displayed by the taxa mentioned permit introduction of a new family Vojnovskytesidae.

  13. Immobilized cells of Candida rugosa possessing fumarase activity

    Energy Technology Data Exchange (ETDEWEB)

    Yang, L.; Zhone, L.

    1980-01-01

    Immobilized cells of C. rugosa that possessed fumarase activity were prepared by different methods; the most active immobilized cells were entrapped in polyacrylamide gels. The effects of pH temperature, and divalent cations on the fumarase activity of both immobilized and native cells were the same. Mn/sup 2 +/, Mg/sup 2 +/, Ca/sup 2 +/, and Fe/sup 2 +/ did not protect the immobilized enzyme against thermal inactivation. The activity of immobilized fumarase remained constant during 91 days of storage of 4-6 degrees. The immobilized cell column was used for the continuous production of L-malic acid from 1M fumarate at 30 degrees and pH 8.5. The immobilized column operated steadily for 2 months. Half life of the immobilized fumarase at 30 degrees was 95 days.

  14. Chemical Fingerprint Analysis and Quantitative Analysis of Rosa rugosa by UPLC-DAD

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    Sanawar Mansur

    2016-12-01

    Full Text Available A method based on ultra performance liquid chromatography with a diode array detector (UPLC-DAD was developed for quantitative analysis of five active compounds and chemical fingerprint analysis of Rosa rugosa. Ten batches of R. rugosa collected from different plantations in the Xinjiang region of China were used to establish the fingerprint. The feasibility and advantages of the used UPLC fingerprint were verified for its similarity evaluation by systematically comparing chromatograms with professional analytical software recommended by State Food and Drug Administration (SFDA of China. In quantitative analysis, the five compounds showed good regression (R2 = 0.9995 within the test ranges, and the recovery of the method was in the range of 94.2%–103.8%. The similarities of liquid chromatography fingerprints of 10 batches of R. rugosa were more than 0.981. The developed UPLC fingerprint method is simple, reliable, and validated for the quality control and identification of R. rugosa. Additionally, simultaneous quantification of five major bioactive ingredients in the R. rugosa samples was conducted to interpret the consistency of the quality test. The results indicated that the UPLC fingerprint, as a characteristic distinguishing method combining similarity evaluation and quantification analysis, can be successfully used to assess the quality and to identify the authenticity of R. rugosa.

  15. 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

  16. Impact of invasive Rosa rugosa on the arthropod fauna of Danish yellow dunes

    DEFF Research Database (Denmark)

    Elleriis, Pernille; Pedersen, Morten Lauge; Toft, Søren

    2015-01-01

    monospecific shrubbery rich in large flowers. We predicted faunal responses according to the changes in resource availability and environmental conditions promoted by this particular invasive plant: increased populations of flower-visiting insects and species of the phytophagous and detritivorous guilds...... and diversity and increased dominance in the rose patches, due to reductions among xerotherm species. The results indicate that considerable faunistic impoverishment of thermophilic dune specialist species can be expected in the future if R. rugosa is allowed to continue its invasion across the dune habitat.......We compared the arthropod fauna of Rosa rugosa patches to the adjacent native yellow dune vegetation by pitfall trapping in the National Park Thy at the Danish North Sea coast. R. rugosa changes the vegetation from a dune grassland (dominated by Ammophila arenaria) poor in flowering plants to a low...

  17. 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.

  18. Chemical Composition and Nematicidal Activity of Essential Oil of Agastache rugosa against Meloidogyne incognita

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    Zhi Wei Deng

    2013-04-01

    Full Text Available The aim of this research was to determine the chemical composition and nematicidal activity of essential oil of Agastache rugosa flowering aerial parts against the root knot nematode, Meloidogyne incognita, and to isolate and identify any nematicidal constituents from the essential oil. The essential oil of A. rugosa aerial parts was obtained by hydrodistillation and analyzed by GC-FID and GC-MS. A total of 37 components of the essential oil were identified, with the principal compounds being methyleugenol (50.51%, estragole (8.55%, and eugenol (7.54%, followed by thymol (3.62%, pulegone (2.56%, limonene (2.49% and caryophyllene (2.38%. Based on bioactivity-guided fractionation, the three active constituents were isolated from the essential oil and identified as methyleugenol, estragole and eugenol. The essential oil of A. rugosa exhibited strong nematicidal activity against M. incognita, with a LC50 value of 47.3 μg/mL. The components eugenol (LC50 = 66.6 μg/mL and methyleugenol (LC50 = 89.4 μg/mL exhibited stronger nematicidal activity against M. incognita (LC50 = 185.9 μg/mL. The results indicate that the essential oil of A. rugosa aerial parts and its constituent compounds have potential for development into natural nematicides for control of the root knot nematode.

  19. Effect of inhibition on tyrosinase and melanogenesis of Agastache rugosa Kuntze by lactic acid bacteria fermentation.

    Science.gov (United States)

    Kim, Nam Young; Kwon, Hee Souk; Lee, Hyeon Yong

    2017-09-01

    This work presents the first report that A. rugosa could have tyrosinase and melanogenesis inhibition and that its activities also be improved by fermentation with Lactobacillus rhamnosus and Lactobacillus paracasei. It was found that the tyrosinase and melanogenesis inhibition was correlated with antioxidant activity of acacetin, the major biologically active substances in A. rugosa. we pursued an improvement in tyrosinase and melanogenesis inhibition of A. rugosa extract by fermentation process. A. rugosa was extracted by lactic acid fermentation process; we measured antioxidant activities and tyrosinase and melanogenesis inhibition of A. rugosa extracts. In particular, reducing power of the extract from fermentation process (FE) was measured as 0.562 (O.D.), whereas reducing power of the extracts from 70% ethanol extraction (EE) was lower than the FE as 0.496 (O.D.). Polyphenols and flavonoids in the FE were higher than the EE: 69.3 mg/g vs. 60.5 mg/g, and 187 mg/g vs. 138 mg/g. The FE was estimated as 51.04% tyrosinase inhibition and 41.88% for the EE. Similarly, melanin inhibition in melanocyte B16F10 was observed as 66.60% vs. 42.23% for the FE and EE. The increase in tyrosinase and melanogenesis inhibition activity was confirmed by high elution of acacetin through fermentation process such as 289.97 mg/100 g vs. 198.04 mg/100 g in the FE and EE. These results indicate that tyrosinase and melanogenesis inhibition activities of the extracts should be associated with antioxidant activity because acacetin is known to have strong antioxidant activity, which can also positively affect whitening activities. © 2016 Wiley Periodicals, Inc.

  20. Five hTRPA1 Agonists Found in Indigenous Korean Mint, Agastache rugosa.

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    Hana Moon

    Full Text Available Transient receptor potential ankyrin1 (TRPA1 and transient receptor potential vanilloid 1 (TRPV1 are members of the TRP superfamily of structurally related, nonselective cation channels and mediators of several signaling pathways. Previously, we identified methyl syringate as an hTRPA1 agonist with efficacy against gastric emptying. The aim of this study was to find hTRPA1 and/or hTRPV1 activators in Agastache rugosa (Fisch. et Meyer O. Kuntze (A.rugosa, commonly known as Korean mint to improve hTRPA1-related phenomena. An extract of the stem and leaves of A.rugosa (Labiatae selectively activated hTRPA1 and hTRPV1. We next investigated the effects of commercially available compounds found in A.rugosa (acacetin, 4-allylanisole, p-anisaldehyde, apigenin 7-glucoside, L-carveol, β-caryophyllene, trans-p-methoxycinnamaldehyde, methyl eugenol, pachypodol, and rosmarinic acid on cultured hTRPA1- and hTRPV1-expressing cells. Of the ten compounds, L-carveol, trans-p-methoxycinnamaldehyde, methyl eugenol, 4-allylanisole, and p-anisaldehyde selectively activated hTRPA1, with EC50 values of 189.1±26.8, 29.8±14.9, 160.2±21.9, 1535±315.7, and 546.5±73.0 μM, respectively. The activities of these compounds were effectively inhibited by the hTRPA1 antagonists, ruthenium red and HC-030031. Although the five active compounds showed weaker calcium responses than allyl isothiocyanate (EC50=7.2±1.4 μM, our results suggest that these compounds from the stem and leaves of A.rugosa are specific and selective agonists of hTRPA1.

  1. 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

  2. Antiulcer action of the hydroalcoholic extract and fractions of Davilla rugosa Poiret in the rat.

    Science.gov (United States)

    Guaraldo, L; Sertiè, J A; Bacchi, E M

    2001-07-01

    Davilla rugosa Poiret ("Cipó- Caboclo") is commonly used in Brazilian folk medicine. The hydroalcoholic extract of the stems (HE) was fractionated with chloroform (CF), chloroform/ethyl acetate (CAF), ethyl acetate (AF), ethyl acetate/ethanol (AEF), ethanol (EF), and ethanol/water (EWF). The hydroalcoholic extract (HE) and fractions of the stems of D. rugosa Poiret were investigated for possible anti gastric ulcer properties. These extracts were shown to protect rats from developing gastric ulcers induced by two acute models: HCl/ethanol (400 mg/kg i.p.) and immersion-restraint stress (15 and 30 mg/kg of the HE and 15 mg/kg either of the ethanol or the ethanol/water fractions, p.o.). The daily oral dose of 800 mg/kg of HE for 30 consecutive days was tested for possible toxic effects. There were no modifications in body weight, water or food intake or in the external aspect of kidneys, spleen, lungs and liver. The only difference observed was a decrease of liver weight. These results suggest that the D. rugosa Poiret HE has an antiulcer activity in rats and the active components are in the two more polar fractions.

  3. Simultaneous production of fatty acid methyl esters and diglycerides by four recombinant Candida rugosa lipase's isozymes.

    Science.gov (United States)

    Chang, Shu-Wei; Huang, Myron; Hsieh, Yu-Hsun; Luo, Ying-Ting; Wu, Tsung-Ta; Tsai, Chia-Wen; Chen, Chin-Shuh; Shaw, Jei-Fu

    2014-07-15

    In this study, the catalytic efficiency of four recombinant CRL (Candida rugosa lipase) isozymes (LIP1-LIP4) towards the production of fatty acid methyl ester (FAME) was compared and evaluated as an alternative green method for industrial applications. The results indicated that the recombinant C. rugosa LIP1 enzyme exhibited the highest catalytic efficiency for FAME production compared to the recombinant C. rugosa LIP2-LIP4 enzymes. The optimal conditions were as follows: pH 7.0, methanol/soybean oil molar ratio: 3/1, enzyme amount: 2U (1.6 μL), reaction temperature: 20°C, 22 h of reaction time, and 3 times of methanol addition (1 mol/6h), and resulted in 61.5 ± 1.5 wt.% of FAME conversion. The reaction product contained also 10 wt.% of DAG with a ratio of 1,3-DAG to 1,2-DAG of approximately 4:6, and can be potentially used in industrial applications as a food emulsifier. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Pollination in Jacaranda rugosa (Bignoniaceae): euglossine pollinators, nectar robbers and low fruit set.

    Science.gov (United States)

    Milet-Pinheiro, P; Schlindwein, C

    2009-03-01

    Nectar robbers access floral nectar in illegitimate flower visits without, in general, performing a pollination service. Nevertheless, their effect on fruit set can be indirectly positive if the nectar removal causes an incremental increase in the frequency of legitimate flower visits of effective pollinators, especially in obligate outcrossers. We studied pollination and the effect of nectar robbers on the reproductive fitness of Jacaranda rugosa, an endemic shrub of the National Park of Catimbau, in the Caatinga of Pernambuco, Brazil. Xenogamous J. rugosa flowers continuously produced nectar during the day at a rate of 1 mul.h(-1). Female and male Euglossa melanotricha were the main pollinators. Early morning flower visits substantially contributed to fruit set because stigmas with open lobes were almost absent in the afternoon. Ninety-nine per cent of the flowers showed damage caused by nectar robbers. Artificial addition of sugar water prolonged the duration of flower visits of legitimate flower visitors. Removal of nectar, simulating the impact of nectar robbers, resulted in shorter flower visits of euglossine bees. While flower visits of nectar-robbing carpenter bees (Xylocopa frontalis, X. grisescens, X. ordinaria) produced only a longitudinal slit in the corolla tube in the region of the nectar chamber, worker bees of Trigona spinipes damaged the gynoecium in 92% of the flowers. This explains the outstandingly low fruit set (1.5%) of J. rugosa in the National Park of Catimbau.

  5. Isolation and characterization of three distinct forms of lipases from Candida rugosa produced in solid state fermentation

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    Sailas Benjamin

    2000-01-01

    Full Text Available Three distinct forms (Lip A, Lip B and Lip C of extra-cellular lipases (EC- 3.1.1.3, produced by Candida rugosa in solid state fermentation (SSF were purified and characterised. SSF was carried out in glass columns using coconut oil cake and wheat bran. The enzyme was purified from the aqueous extract of fermented matter by ammonium sulphate precipitation, dialysis, ultra-filtration and gel filtration using Sephadex-200 to a 43-fold purification and 64.35-mg/ml specific activity. SDS-PAGE of purified enzyme revealed three distinct bands, indicating the existence of three iso-forms, Lip A, Lip B and Lip C with apparent molecular weight about 64,000, 62,000 and 60,000 Da, respectively. All the three iso-forms were optimally active at 35-40ºC and pH 7-8. They showed marked differences in their Km values with different saturated and unsaturated triacyl glycerols. Ag++ and Hg++ strongly inhibited enzyme activity of all the iso-forms, Mn++ has no effect and Ca++ and Mg++ enhanced the activity. EDTA also strongly inhibited the enzyme activities of iso-forms. However, activities of all the three lipases were completely inhibited by serine protease inhibitors such as 3,4-dichloroisocoumarin, pefabloc and partially by phenylmethanesulphonyl fluoride. To the best of our knowledge, this is the first report describing the purification and characterisation of C. rugosa lipase iso-forms from solid cultures. These lipase iso-forms with diverse characteristics produced in solid cultures may find potential application in biomedical field.Três formas distintas (Lip A, Lip B e Lip C de lipases extracelulares (EC- 3,1,1,3, produzidas por Candida rugosa em fermentação no estado sólido (SSF foram purificadas e caracterizadas. A fermentação foi realizada em colunas de vidro usando como substrato bolo de óleo de coco e o farelo de trigo. O enzima obtida no extrato aquoso do material fermentado foi precipitada com do sulfato de do amônio, dialisada , ultra

  6. 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

  7. Metabolomics analysis and biosynthesis of rosmarinic acid in Agastache rugosa Kuntze treated with methyl jasmonate.

    Directory of Open Access Journals (Sweden)

    Yeon Bok Kim

    Full Text Available This study investigated the effect of methyl jasmonate (MeJA on metabolic profiles and rosmarinic acid (RA biosynthesis in cell cultures of Agastache rugosa Kuntze. Transcript levels of phenylpropanoid biosynthetic genes, i.e., ArPAL, Ar4CL, and ArC4H, maximally increased 4.5-fold, 3.4-fold, and 3.5-fold, respectively, compared with the untreated controls, and the culture contained relatively high amounts of RA after exposure of cells to 50 µM MeJA. RA levels were 2.1-, 4.7-, and 3.9-fold higher after exposure to 10, 50, and 100 µM MeJA, respectively, than those in untreated controls. In addition, the transcript levels of genes attained maximum levels at different time points after the initial exposure. The transcript levels of ArC4H and Ar4CL were transiently induced by MeJA, and reached a maximum of up to 8-fold at 3 hr and 6 hr, respectively. The relationships between primary metabolites and phenolic acids in cell cultures of A. rugosa treated with MeJA were analyzed by gas chromatography coupled with time-of-flight mass spectrometry. In total, 45 metabolites, including 41 primary metabolites and 4 phenolic acids, were identified from A. rugosa. Metabolite profiles were subjected to partial least square-discriminate analysis to evaluate the effects of MeJA. The results indicate that both phenolic acids and precursors for the phenylpropanoid biosynthetic pathway, such as aromatic amino acids and shikimate, were induced as a response to MeJA treatment. Therefore, MeJA appears to have an important impact on RA accumulation, and the increased RA accumulation in the treated cells might be due to activation of the phenylpropanoid genes ArPAL, ArC4H, and Ar4CL.

  8. Effects of Carbon and Nitrogen Sources on Lipase Production by Candida rugosa

    OpenAIRE

    ERKMEN, Sibel FADILOĞLU and Osman

    2014-01-01

    The production of lipase by Candida rugosa growing on media with various carbon and nitrogen sources was studied. While high yields of enzyme activity (5.58 U mL-1) were obtained with yeast extract and proteose-peptone in the medium with olive oil, the minimum lipase activity (2.81 U mL-1) was observed with tryptone and lactose. In the absence of olive oil, the media with proteose peptone and glucose gave the maximum enzyme activity (2.21 U mL-1). The best results in the production of lipa...

  9. 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 ...

  10. 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.

  11. 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 ...

  12. 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 ...

  13. Candida/Candida biofilms. First description of dual-species Candida albicans/C. rugosa biofilm.

    Science.gov (United States)

    Martins, Carlos Henrique Gomes; Pires, Regina Helena; Cunha, Aline Oliveira; Pereira, Cristiane Aparecida Martins; Singulani, Junya de Lacorte; Abrão, Fariza; Moraes, Thais de; Mendes-Giannini, Maria José Soares

    2016-04-01

    Denture liners have physical properties that favour plaque accumulation and colonization by Candida species, irritating oral tissues and causing denture stomatitis. To isolate and determine the incidence of oral Candida species in dental prostheses, oral swabs were collected from the dental prostheses of 66 patients. All the strains were screened for their ability to form biofilms; both monospecies and dual-species combinations were tested. Candida albicans (63 %) was the most frequently isolated microorganism; Candida tropicalis (14 %), Candida glabrata (13 %), Candida rugosa (5 %), Candida parapsilosis (3 %), and Candida krusei (2 %) were also detected. The XTT assay showed that C. albicans SC5314 possessed a biofilm-forming ability significantly higher (p biofilm was less than the total CFU of a monospecies C. albicans biofilm. In contrast to the profuse hyphae verified in monospecies C. albicans biofilms, micrographies showed that the C. albicans/non-albicans Candida biofilms consisted of sparse yeast forms and profuse budding yeast cells that generated a network. These results suggested that C. albicans and the tested Candida species could co-exist in biofilms displaying apparent antagonism. The study provide the first description of C. albicans/C. rugosa mixed biofilm. Copyright © 2016 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  14. Antimicrobial, antibiofilm and antitumor activities of essential oil of Agastache rugosa from Xinjiang, China

    Directory of Open Access Journals (Sweden)

    Gong Haiyan

    2016-07-01

    Full Text Available In the study, we evaluated chemical composition and antimicrobial, antibiofilm, and antitumor activities of essential oils from dried leaf essential oil of leaf and flower of Agastache rugosa for the first time. Essential oil of leaf and flower was evaluated with GC and GC–MS methods, and the essential oil of flower revealed the presence of 21 components, whose major compounds were pulegone (34.1%, estragole (29.5%, and p-Menthan-3-one (19.2%. 26 components from essential oil of leaf were identified, the major compounds were p-Menthan-3-one (48.8% and estragole (20.8%. At the same time, essential oil of leaf, there is a very effective antimicrobial activity with MIC ranging from 9.4 to 42 μg ml−1 and potential antibiofilm, antitumor activities for essential oils of flower and leaf essential oil of leaf. The study highlighted the diversity in two different parts of A. rugosa grown in Xinjiang region and other places, which have different active constituents. Our results showed that this native plant may be a good candidate for further biological and pharmacological investigations.

  15. Rickettsia Detected in the Reptile Tick Bothriocroton hydrosauri from the Lizard Tiliqua rugosa in South Australia

    Directory of Open Access Journals (Sweden)

    Harriet Whiley

    2016-06-01

    Full Text Available Rickettsiosis is a potentially fatal tick borne disease. It is caused by the obligate intracellular bacteria Rickettsia, which is transferred to humans through salivary excretions of ticks during the biting process. Globally, the incidence of tick-borne diseases is increasing; as such, there is a need for a greater understanding of tick–host interactions to create more informed risk management strategies. Flinders Island spotted fever rickettsioses has been identified throughout Australia (Tasmania, South Australia, Queensland and Torres Strait Islands with possible identifications in Thailand, Sri Lanka and Italy. Flinders Island spotted fever is thought to be spread through tick bites and the reptile tick Bothriocroton hydrosauri has been implicated as a vector in this transmission. This study used qPCR to assay Bothriocroton hydrosauri ticks collected from Tiliqua rugosa (sleepy lizard hosts on mainland South Australia near where spotted fever cases have been identified. We report that, although we discovered Rickettsia in all tick samples, it was not Rickettsia honei. This study is the first to use PCR to positively identify Rickettsia from South Australian Bothriocroton hydrosauri ticks collected from Tiliqua rugosa (sleepy lizard hosts. These findings suggest that B. hydrosauri may be a vector of multiple Rickettsia spp. Also as all 41 tested B. hydrosauri ticks were positive for Rickettsia this indicates an extremely high prevalence within the studied area in South Australia.

  16. Adsorption of Candida rugosa lipase at water-polymer interface: The case of poly( DL)lactide

    Science.gov (United States)

    Kamel, Gihan; Bordi, Federico; Chronopoulou, Laura; Lupi, Stefano; Palocci, Cleofe; Sennato, Simona; Verdes, Pedro V.

    2011-12-01

    Insights into the interactions between biological macromolecules and polymeric surfaces are of great interest because of potential uses in developing biotechnologies. In this study we focused on the adsorption of a model lipolytic enzyme, Candida rugosa lipase (CRL), on poly-(D,L)-lactic acid (PDLLA) polymer with the aim to gain deeper insights into the interactions between the enzyme and the carrier. Such studies are of particular relevance in order to establish the optimal conditions for enzyme immobilization and its applications. We employed two different approaches; by analyzing the influence of adsorbed CRL molecules on the thermodynamic behavior of Langmuir films of PDLLA deposited at air-water interface, we gained interesting information on the molecular interactions between the protein and the polymer. Successively, by a systematic analysis of the adsorption of CRL on PDLLA nanoparticles, we showed that the adsorption of a model lipase, CRL, on PDLLA is described in terms of a Langmuir-type adsorption behavior. In this model, only monomolecular adsorption takes place (i.e. only a single layer of the protein adsorbs on the support) and the interactions between adsorbed molecules and surface are short ranged. Moreover, both the adsorption and desorption are activated processes, and the heat of adsorption (the difference between the activation energy for adsorption and desorption) is independent from the surface coverage of the adsorbing species. Finally, we obtained an estimate of the number of molecules of the protein adsorbed per surface unit on the particles, a parameter of a practical relevance for applications in biocatalysis, and a semi-quantitative estimate of the energies (heat of adsorption) involved in the adsorption process.

  17. High-yield conversion of (R)-2-octanol from the corresponding racemate by stereoinversion using Candida rugosa.

    Science.gov (United States)

    Nie, Yao; Xu, Yan; Qing Mu, Xiao; Tang, Yan; Jiang, Juan; Hao Sun, Zhi

    2005-01-01

    Whole cells of Candida rugosa catalyzed the conversion of (R)-2-octanol from the corresponding racemate with the optical purity of 97% e.e. and yield of 92% in 10 h. The product was formed through a stereoinversion involving enantioselective oxidation and asymmetric reduction with 2-octanone as the intermediate.

  18. Flowery odor formation revealed by differential expression of monoterpene biosynthetic genes and monoterpene accumulation in rose (Rosa rugosa Thunb.).

    Science.gov (United States)

    Feng, Liguo; Chen, Chen; Li, Tinglin; Wang, Meng; Tao, Jun; Zhao, Daqiu; Sheng, Lixia

    2014-02-01

    Rosa rugosa is an important ornamental and economical plant. In this paper, four genes encoding 1-deoxy-D-xylulose-5-phosphate synthase (DXS), 1-deoxy-d-xylulose-5-phosphate reductoisomerase (DXR), alcohol acyltransferase (AAT) and linalool synthase (LIS) involved in the monoterpene biosynthesis pathways were isolated from R. rugosa 'Tangzi', and the expression patterns of these genes in different flower development stages and different parts of floral organs were determined by real-time quantitative fluorescence PCR. Furthermore, a comprehensive analysis was carried out into the relationship between expression of four monoterpene synthesis genes and accumulation of main volatile monoterpenes and their acetic acid ester derivatives. The results showed that the genes RrDXS, RrDXR and RrLIS showed consistent expressions during the development process for R. rugosa flower from budding to withering stage, the overall expression levels of gene RrDXS and RrLIS were obviously lower as compared with those of gene RrDXR and RrAAT. Although the gene RrDXS, RrDXR, RrAAT and RrLIS were expressed in all parts of R. rugosa floral organs, the expression levels varied significantly. The variations in the constituent and content of volatile monoterpenes including citronellol, geraniol, nerol, linalool, citronellyl acetate, geranyl acetate and neryl acetate at different development stages and parts of floral organs were significantly different. On this basis, we concluded that the gene RrDXR and RrAAT might play a key role in the biosynthesis of volatile monoterpenes in R. rugosa flowers, and the two genes are important candidate genes for the regulation of secondary metabolism for rose aromatic components. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  19. Covalent immobilization of lipase from Candida rugosa on Eupergit®

    Directory of Open Access Journals (Sweden)

    Bezbradica Dejan I.

    2005-01-01

    Full Text Available An approach is presented for the stable covalent immobilization of Upase from Candida rugosa on Eupergit® with a high retention of hydrolytic activity. It comprises covalent bonding via lipase carbohydrate moiety previously modified by periodate oxidation, allowing a reduction in the involvement of the enzyme functional groups that are probably important in the catalytic mechanism. The hydrolytic activities of the lipase immobilized on Eupergif1 by two conventional methods (via oxirane group and via glutaralde-hyde and with periodate method were compared. Results of lipase assays suggest that periodate method is superior for lipase immobilization on Eupergit® among methods applied in this study with respect to both, yield of immobilization and hydrolytic activity of the immobilized enzyme.

  20. Synthesis of medium-chain length capsinoids from coconut oil catalyzed by Candida rugosa lipases.

    Science.gov (United States)

    Trbojević Ivić, Jovana; Milosavić, Nenad; Dimitrijević, Aleksandra; Gavrović Jankulović, Marija; Bezbradica, Dejan; Kolarski, Dušan; Veličković, Dušan

    2017-03-01

    A commercial preparation of Candida rugosa lipases (CRL) was tested for the production of capsinoids by esterification of vanillyl alcohol (VA) with free fatty acids (FA) and coconut oil (CO) as acyl donors. Screening of FA chain length indicated that C8-C12 FA (the most common FA found in CO triglycerides) are the best acyl-donors, yielding 80-85% of their specific capsinoids. Hence, when CO, which is rich in these FA, was used as the substrate, a mixture of capsinoids (vanillyl caprylate, vanillyl decanoate and vanillyl laurate) was obtained. The findings presented here suggest that our experimental method can be applied for the enrichment of CO with capsinoids, thus giving it additional health promoting properties. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    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.

  2. First records of Rhicnoda natatrix and Rhicnoda rugosa (Blattodea: Blaberidae from Nepal and India (Maharashtra with notes on habitat quality

    Directory of Open Access Journals (Sweden)

    H. Nesemann

    2010-01-01

    Full Text Available Two species of cockroaches were collected from aquatic habitats of undisturbed natural forest streams in Nepal and India (Maharashtra: Rhicnoda natatrix and Rhicnoda rugosa. Nymphs and adults are depicted and field observations of microhabitat and behavior described. Taxa lists of accompanying macroinvertebrate fauna are given, and water quality class is calculated using three biotic scoring systems. R. natatrix is a true aquatic species with amphibious lifestyle in the eulittoral of springs (Crenon and streams (Rhithron of excellent and good water quality classes I and II. R. rugosa is a predominantly terrestrial species that also colonizes the banks of water bodies and appears in between aquatic fauna. These species cannot be classified using the traditional habitat system.

  3. 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

  4. UPLC-PDA-Q/TOF-MS Profile of Polyphenolic Compounds of Liqueurs from Rose Petals (Rosa rugosa).

    Science.gov (United States)

    Cendrowski, Andrzej; Ścibisz, Iwona; Kieliszek, Marek; Kolniak-Ostek, Joanna; Mitek, Marta

    2017-10-27

    Polyphenolic compounds, as a secondary metabolite of plants, possess great nutritional and pharmacological potential. Herein, we applied the green analytical method to study the nutrient profile of Rosa rugosa petals and liqueurs manufactured from them. Using the fast and validated ultra performance liquid chromatography-photodiode detector-quadrupole/time of flight-mass spectrometry (UPLC-PDA-Q/TOF-MS) method, we confirm the presence of the following compounds: phenolic acids, flavonols, flavan-3-ols and hydrolisable tannins (gallotannins and ellagitannins). R. rugosa petals contains up to 2175.43 mg polyphenols per 100 g fresh weight, therein 1517.01 mg ellagitannins per 100 g fresh weight. Liqueurs, traditionally manufactured from said petals using a conventional extraction method (maceration), also contain polyphenols in significant amounts (from 72% to 96% corresponding to percentage of theoretical polyphenol content in the used petals), therein ellagitannins amount to 69.7% on average. We confirmed that traditional maceration, most common for the isolation of polyphenols, is still suitable for the food industry due to its using aqueous ethanol, a common bio-solvent, easily available in high purity and completely biodegradable. Therefore R. rugosa used as a food may be considered as an ellagitannin-rich plant of economic importance. Manufactured rose liqueurs were stable and kept all their properties during the whole period of aging.

  5. Estudo farmacognóstico comparativo das folhas de Davilla elliptica A. St.-Hil. e D. rugosa Poir., Dilleniaceae

    Directory of Open Access Journals (Sweden)

    Rose Lisieux R. Paiva Jácome

    Full Text Available As características farmacognósticas das folhas de Davilla elliptica A. St.-Hil. e D. rugosa Poir., Dilleniaceae, foram determinadas com objetivo de auxiliar na identificação taxonômica e no controle de qualidade das drogas vegetais e de produtos fitoterápicos. A espécie D. elliptica é um arbusto ereto, que ocorre naturalmente no cerrado e D. rugosa é um trepadeira lenhosa de beira de mata. Ambas são conhecidas popularmente como lixeirinha, sambaibinha e cipó-caboclo, empregadas na medicina tradicional como antiinflamatória e antiúlcera. As características microscópicas observadas em D. rugosa tais como tricomas estrelados e esclereídes no mesofilo e em D. elliptica de idioblastos contendo mucilagem e endoderme, são parâmetros que poderão ser utilizados na diferenciação das espécies. Os teores obtidos nos ensaios de pureza e nos doseamentos de taninos (9,4% e 7,2%, flavonoides (0,46% e 0,9% e mucilagens (2,2% e 4,1% de ambas as espécies, podem contribuir no controle de qualidade das drogas vegetais uma vez que são usadas indistintamente na produção de fitoterápicos.

  6. 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...

  7. 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....

  8. Conversion of crude Jatropha curcas seed oil into biodiesel using liquid recombinant Candida rugosa lipase isozymes.

    Science.gov (United States)

    Kuo, Ting-Chun; Shaw, Jei-Fu; Lee, Guan-Chiun

    2015-09-01

    The versatile Candida rugosa lipase (CRL) has been widely used in biotechnological applications. However, there have not been feasibility reports on the transesterification of non-edible oils to produce biodiesel using the commercial CRL preparations, mixtures of isozymes. In the present study, four liquid recombinant CRL isozymes (CRL1-CRL4) were investigated to convert various non-edible oils into biodiesel. The results showed that recombinant CRL2 and CRL4 exhibited superior catalytic efficiencies for producing fatty acid methyl ester (FAME) from Jatropha curcas seed oil. A maximum 95.3% FAME yield was achieved using CRL2 under the optimal conditions (50 wt% water, an initial 1 equivalent of methanol feeding, and an additional 0.5 equivalents of methanol feeding at 24h for a total reaction time of 48 h at 37 °C). We concluded that specific recombinant CRL isozymes could be excellent biocatalysts for the biodiesel production from low-cost crude Jatropha oil. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    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.

  10. 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...

  11. The hematology of captive Bobtail lizards (Tiliqua rugosa): blood counts, light microscopy, cytochemistry, and ultrastructure.

    Science.gov (United States)

    Moller, Cheryl A; Gaál, Tibor; Mills, Jennifer N

    2016-12-01

    Bobtail lizards (Tiliqua rugosa) are native to Australia. The only previous study on the hematology of this species documented just 6 animals. The aims of this study were to characterize the light microscopy, ultrastructure and cytochemistry of blood cells, and evaluate CBCs of captive Bobtail lizards. Over 2 consecutive summers, heparinized venous blood was collected from the ventral coccygeal vein of 46 clinically healthy, captive indoor- or outdoor-housed adult Bobtails. Complete blood cell counts and smear evaluations were performed, and cytochemical stains and transmission electron microscopy were used to further characterize blood cells. The eosinophils of this species were uniformly vacuolated: a unique feature not previously reported in reptiles. Heterophils were the predominant leukocyte, with fewer lymphocytes, azurophilic and nonazurophilic monocytes, occasional eosinophils, and basophils. Thrombocytes were frequently clumped. Slight polychromasia (0-15% of erythrocytes) was typically present. Hemogregarine parasites were seen on some smears. The range of CBC results was often wide. The PCV ranged from 11% to 38%. Total plasma proteins by refractometry were between 3.5 and 7.8 g/dL. Hemoglobin ranged between 2.6 and 12.6 g/dL by the modified hemoglobin-hydroxylamine method. Manual RBC count was 0.35-1.27 × 10 6 /μL, and WBC count was 2.86-22.66 × 10 3 /μL. Bobtail lizards housed outdoors had lower PCVs than indoor-housed animals. Bobtails with hemogregarine infections had lower PCVs than noninfected lizards. Ranges for CBC data were often very wide, influenced by preanalytic and analytic factors. Hemogregarine infection is associated with a decreased PCV, suggesting that some hemogregarine species are pathogenic in this population. © 2016 American Society for Veterinary Clinical Pathology.

  12. Widespread bacterial infection affecting Rana temporaria tadpoles in mountain areas

    Directory of Open Access Journals (Sweden)

    Rocco Tiberti

    2011-06-01

    Full Text Available Periodic mass die-offs of Rana temporaria tadpole populations have occurred in the ponds of prealpine mountain areas of Brescia (northern Italy since the early 2000s. The author reports some observational data and analytical results from three sites: tadpoles from mortality events had erythema, especially on the legs, suggestive of septicemia. Bacterial culture of these tadpoles revealed Aeromonas hydrophila and Aeromonas sobria, two organisms often associated with Red leg disease. Egg mass counts from 29 pastureland ponds did not revealed breeding activity declines over five years in the Monte Guglielmo area. Aeromonas hydrophila and Aeromonas sobria usually behave as opportunistic bacteria that can become pathogenic after suppression of the immune system by endogenous or exogenous stressors. Thus, a plurality of environmental factors may contribute to mortality events; some of them are discussed, including loss of high altitude breeding ponds resulting in overcrowding and poor water quality in remaining ponds and the presence of other pathogens.

  13. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  15. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. Distribution of 45S rDNA in Modern Rose Cultivars (Rosa hybrida), Rosa rugosa, and Their Interspecific Hybrids Revealed by Fluorescence in situ Hybridization.

    Science.gov (United States)

    Ding, Xiao-Liu; Xu, Ting-Liang; Wang, Jing; Luo, Le; Yu, Chao; Dong, Gui-Min; Pan, Hui-Tang; Zhang, Qi-Xiang

    2016-01-01

    To elucidate the evolutionary dynamics of the location and number of rDNA loci in the process of polyploidization in the genus Rosa, we examined 45S rDNA sites in the chromosomes of 6 modern rose cultivars (R. hybrida), 5 R. rugosa cultivars, and 20 hybrid progenies by fluorescence in situ hybridization. Variation in the number of rDNA sites in parents and their interspecific hybrids was detected. As expected, 4 rDNA sites were observed in the genomes of 4 modern rose cultivars, while 3 hybridization sites were observed in the 2 others. Two expected rDNA sites were found in 2 R. rugosa cultivars, while in the other 3 R. rugosa cultivars 4 sites were present. Among the 20 R. hybrida × R. rugosa offspring, 13 carried the expected number of rDNA sites, and 1 had 6 hybridization sites, which exceeded the expected number by far. The other 6 offspring had either 2 or 3 hybridization sites, which was less than expected. Differences in the number of rDNA loci were observed in interspecific offspring, indicating that rDNA loci exhibit instability after distant hybridization events. Abnormal chromosome pairing may be the main factor explaining the variation in rDNA sites during polyploidization. © 2016 S. Karger AG, Basel.

  18. THE MOCHE BOTANICAL FROG (La rana botánica mochica

    Directory of Open Access Journals (Sweden)

    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.

  19. 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

  20. 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.

  1. Variação sazonal nos teores de flavonoides, taninos e atividade antioxidante de Davilla rugosa Poir.

    Directory of Open Access Journals (Sweden)

    Jéssica Marques Macedo

    2013-12-01

    Full Text Available Davilla rugosa Poir. (Dilleniaceae é uma trepadeira, conhecida como folha de lixa e cipó-cabloco, com distribuição geográfica ampla no Brasil. É utilizada como analgésica, vasoconstritora, antiúlcera, útil no tratamento das hemorroidas e varizes. O objetivo do trabalho foi investigar a influência da variação sazonal sobre alguns parâmetros das folhas de D. rugosa, como os teores de flavonoides e taninos. Os teores de flavonoides e taninos, determinados nas 4 estações do ano, foram avaliados segundo a Farmacopeia Brasileira e foram mais elevados no verão (0,71%; 16,73% seguido do outono (0,58%; 16,39%. Considerando que substâncias fenólicas são, provavelmente, os responsáveis pela atividade anti-inflamatória e antiulcerogênica, podemos inferir que a melhor época de coleta, que conduza a uma matéria-prima com concentrações desejáveis de princípios ativos, é, preferencialmente, no verão seguida do outono. A atividade antioxidante do extrato de acetato de etila, desengordurado com hexano, submetido ao teste do DPPH, apresentou uma CE50 de 24,73 ± 2,95 µg/ mL e no ensaio do fosfomobdênio de 1,85 ±0,57 mmol de ácido ascórbico/mg de extrato seco. A atividade antioxidante encontrada nos extratos reforça os efeitos anti-inflamatórios e antiúlcera gástrica atribuídos para a espécie.

  2. Abundance of Alnus incana ssp. rugosa in Adirondack Mountain shrub wetlands and its influence on inorganic nitrogen

    International Nuclear Information System (INIS)

    Kiernan, B.D.; Hurd, T.M.; Raynal, D.J.

    2003-01-01

    The presence of the nitrogen-fixing shrub, Alnus incana ssp. rugosa, influences the concentration of inorganic nitrogen in surface waters in the Adirondack Mountain region of northern New York. - The purpose of this research was to determine the abundance of the nitrogen-fixing shrub, Alnus incana ssp. rugosa (speckled alder), in shrub wetlands of the Adirondack Mountain region of New York State and to determine whether its abundance affects the concentration or accumulation of inorganic nitrogen in wetland substrates. Alder/willow wetlands are the second most common wetland type in the Adirondack region. The Adirondack Park Agency's digital GIS database of wetland types was used to determine the areal extent of alder/willow wetlands in the Adirondacks. Randomly selected wetlands were sampled to determine the size and abundance of alder. Alder densities averaged ∼7000 stems ha -1 and alder was present in 75% of the wetlands. As an indication of short-term accumulation of NO 3 - and NH 4 + in wetland substrates, ion exchange resins were used to sample ground water in high and low alder density wetlands as well as from wetlands lacking alder and dominated by conifers. Additionally, NO 3 - and NH 4 + concentrations in ground water samples were measured. NH 4 + accumulation levels from exchange resins were low for all wetland types while groundwater NH 4 + concentration was highest in the low-density alder sites. Wetlands with high alder density had approximately six times higher NO 3 - accumulation than other wetlands. Substrate groundwater NO 3 - concentrations in wetlands of high-density alder exceeded by three times levels in low or no alder wetlands, showing the importance of alder to local N budgets. To assess the recovery of shrub wetlands from acidification, future studies should determine the fate of fixed N in wetland systems

  3. 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.

  4. Efecto antiinflamatorio y antioxidante de los flavonoides de las hojas de Jungia rugosa Less (matico de puna en un modelo experimental en ratas

    Directory of Open Access Journals (Sweden)

    Edwin Enciso

    2011-12-01

    Full Text Available Objetivos: Evaluar la actividad antiinflamatoria y antioxidante de la fracción flavónica extraída de las hojas de Jungia rugosa Less. Diseño: Experimental. Lugar: Facultades de Medicina y Farmacia y Bioquímica, Universidad Nacional Mayor de San Marcos, Lima, Perú. Material biológico: Fracción flavónica extraído de las hojas de Jungia rugosa Less y ratas. Intervenciones: Las hojas de Jungia rugosa Less fueron recolectadas en el cerro Condorcunca, a 3 500 msnm, distrito de Quinua, departamento de Ayacucho. La actividad antiinflamatoria fue evaluada in vivo usando el método de edema plantar inducido por carragenina y en sangre se cuantificó los niveles séricos de interleuquinas 1, 6 y proteína C reactiva (PCR; también, se indujo el granuloma, según Sedwicks, evaluándose por histopatología. La actividad antioxidante fue evaluada in vitro mediante la neutralización del radical 1,1-difenil-2-picril-hidrazilo (DPPH. Principales medidas de resultados: Actividad antiinflamatoria y antioxidante. Resultados: La inflamación disminuyó en 43,8%, y los niveles de interleuquinas 1, 6 y PCR lo fueron en 80%, 90% y 78%, respectivamente, al ser comparados con el control (p<0,05, siendo el efecto dosis dependiente, y brindó un 97,7% de inhibición de radicales DPPH. Conclusión: Se ha demostrado que la fracción flavónica extraída de las hojas de Jungia rugosa Less es antiinflamatoria y antioxidante.

  5. 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...

  6. 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

  7. Long-Term United Kindrom Trends in the Breeding Phenology of the Common Frog, Rana temporaria

    Czech Academy of Sciences Publication Activity Database

    Scott, W.A.; Pithart, David; Adamson, J. K.

    2008-01-01

    Roč. 42, č. 1 (2008), s. 89-96 ISSN 0022-1511 Institutional research plan: CEZ:AV0Z60870520 Keywords : Long-term * Common Frog * Breeding * Rana temporaria Subject RIV: EG - Zoology Impact factor: 0.888, year: 2008

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

    Directory of Open Access Journals (Sweden)

    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.

  9. 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...

  10. 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...

  11. 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...

  12. Estudo fitoquímico de Davilla rugosa: flavonóides e terpenóides

    Directory of Open Access Journals (Sweden)

    Jorge M. David

    Full Text Available Este trabalho descreve o isolamento e caracterização de alguns metabólitos presentes nos caules de Davilla rugosa (Dilleniaceae, conhecida vulgarmente como cipó-caboclo e utilizada pela população na medicina tradicional brasileira para diversas enfermidades. O extrato hidrometanólico foi particionado entre hexano, clorofórmio e acetato de etila. Da fase hexânica foram obtidos a friedelina, sitostenona e ácido betulínico. Da fase clorofórmica foram isolados através de técnicas cromatográficas o ácido betulínico e a narigenina. Enquanto que do extrato acetato de etila foram obtidos dois outros flavonóides, quercetina e 4’-O-metil taxifolina. As substâncias tiveram suas estruturas elucidadas através da análise de dados no UV e de RMN.

  13. Efecto de calidad de planta, exposición y micrositio en una plantación de Quercus rugosa

    Directory of Open Access Journals (Sweden)

    A. Ramírez Contreras

    2004-01-01

    Full Text Available En la Sierra de Guadalupe, Estado de México, fueron plantados árboles de Quercus rugosa Née de dos calidades (planta chica, con 8-15 cm de altura y <2 mm de diámetro en la base, y planta grande con 16-24 cm de altura y 2-4 mm de diámetro, sobre dos exposiciones (NE y SO y en tres condiciones de micrositio (al NE y al SO de rocas y un testigo sin roca. Lo anterior para evaluar su supervivencia y crecimiento un año después de plantados. El experimento fue analizado con un procedimiento mixto. Se encontró que los tres factores fueron significativos, mas no sus interacciones. La planta grande tuvo mayor supervivencia que la chica (37 y 26 %; la exposición noreste arrojó mejor supervivencia que la suroeste (45 y 16 %; y las plantas con micrositio tuvieron mayores valores que el testigo (41 % al NE, 32 % al SO y 20 % para el testigo. El efecto aditivo de la mejor condición de cada factor (planta grande, exposición noreste, al noreste de roca implica una supervivencia igual a 64 %. La peor condición fue para los árboles chicos, sobre exposición suroeste y sin micrositio, con 0 % de supervivencia.

  14. Characterization, optimization and stability studies on Candida rugosa lipase supported on nanocellulose reinforced chitosan prepared from oil palm biomass.

    Science.gov (United States)

    Elias, Nursyafiqah; Chandren, Sheela; Razak, Fazira Ilyana Abdul; Jamalis, Joazaizulfazli; Widodo, Nashi; Wahab, Roswanira Abdul

    2018-03-22

    The contribution of chitosan/nanocellulose (CS-NC) to the enzymatic activity of Candida rugosa lipase covalently bound on the surface of CS-NC (CRL/CS-NC) was investigated. Cellulosic material from oil palm frond leaves (OPFL) were bleached, alkaline treated and acid hydrolyzed to obtain the purified NC and used as nano-fillers in CS. XRD, Raman spectroscopy and optical fluorescence microscopic analyses revealed existence of strong hydrogen bonds between CS and the NC nanofillers. The CRLs were successfully conjugated to the surface of the CS-NC supports via imine bonds that occurred through a Schiff's based mechanism. Process parameters for the immobilization of CRL were assessed for factors temperature, concentration of glutaraldehyde and pH, to afford the highest enzyme activity to achieve maximum conversion of butyl butyrate within 3h of incubation. Conversion as high as 88% was reached under an optimized condition of 25°C, 0.3% glutaraldehyde concentration and buffer at pH7. Thermal stability of CRL/CS-NCs was 1.5-fold greater than that of free CRL, with biocatalysts reusability for up to 8 successive esterification cycles. This research provides a promising approach for expanding the use of NC from OPFL for enhancing enzyme activity in favour of an alternative eco-friendly means to synthesize butyl butyrate. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Estrutura populacional de Kielmeyera rugosa Choisy (Clusiaceae no Parque Nacional Serra de Itabaiana, Estado do Sergipe =Population structure of Kielmeyera rugosa Choisy (Clusiaceae at Serra de Itabaiana National Park, Sergipe State

    Directory of Open Access Journals (Sweden)

    Túlio Vinicius Paes Dantas

    2010-04-01

    Full Text Available Estudos de estrutura de tamanho e de estágios ontogênicos são importantes para se compreender quais fatores influenciam os processos populacionais, a regeneração e a resposta a perturbações de uma população. Este estudo analisou a estrutura de uma população de Kielmeyera rugosa Choisy (Clusiaceae no hábitat de Areias Brancas do Parque Nacional Serra de Itabaiana, Estado de Sergipe. Amostraram-se aleatoriamente 30 parcelas de 20 x 25 m, nas quais se determinou a abundância de indivíduos jovens e adultos, a circunferência do tronco, a altura da copa e o número de caules por planta. A distribuição espacial de jovens e adultos na população é agregada, causada por sua predisposição em formar grupos em locais onde há maiordisponibilidade de recursos e condições favoráveis. Outro fator que contribui com a agregação é a dispersão anemocórica da espécie. A população estudada apresentou o maior número de indivíduos nas categorias menores de altura e de DAS, indicando que a população está em crescimento ou em processo de autorregeneração. Há maior número de indivíduos de 2-3 m de altura, o que se deve ao fogo ou corte, eventos que não foram capazes de interromper o processo de recrutamento ou reprodução da espécie na área, pois não ocorreram lacunas nas classes de diâmetro de caule.Studies on structure, size and ontogenic stages are important to understand which factors influence population processes, regeneration and response to disturbances of a population. This study examined thestructure of a population of Kielmeyera rugosa Choisy (Clusiaceae in white sands habitat of Serra de Itabaiana, Sergipe State. Thirty 20 x 25 m plots were selected randomly selected, and their abundance of young and adult plants was recorded, as well as trunk circumference, crown height and number of stems per plant. The spatial distribution of young and adult population is aggregated, caused by their predisposition to form

  16. Antistress Effects of Rosa rugosa Thunb. on Total Sleep Deprivation-Induced Anxiety-Like Behavior and Cognitive Dysfunction in Rat: Possible Mechanism of Action of 5-HT6 Receptor Antagonist.

    Science.gov (United States)

    Na, Ju-Ryun; Oh, Dool-Ri; Han, SeulHee; Kim, Yu-Jin; Choi, EunJin; Bae, Donghyuck; Oh, Dong Hwan; Lee, Yoo-Hyun; Kim, Sunoh; Jun, Woojin

    2016-09-01

    Our previous results suggest that the Rosa rugosa Thunb. (family Rosaceae) alleviates endurance exercise-induced stress by decreasing oxidative stress levels. This study aimed to screen and identify the physiological antistress effects of an extract of R. rugosa (RO) on sleep deprivation-induced anxiety-like behavior and cognitive tests (in vivo) and tested for hippocampal CORT and monoamine levels (ex vivo), corticosterone (CORT)-induced injury, N-methyl-d-aspartate (NMDA) receptor, and serotonin 6 (5-hydroxytryptamine 6, 5-HT6) receptor activities (in vitro) in search of active principles and underlying mechanisms of action. We confirmed the antistress effects of RO in a sleep-deprived stress model in rat and explored the underlying mechanisms of its action. In conclusion, an R. rugosa extract showed efficacy and potential for use as an antistress therapy to treat sleep deprivation through its antagonism of the 5-HT6 receptor and resulting inhibition of cAMP activity.

  17. 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...

  18. 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.

  19. O sufixo -rana no português falado pelo caboclo amazonense

    Directory of Open Access Journals (Sweden)

    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.

  20. Spatial Variation and Survival of Salmonella enterica Subspecies in a Population of Australian Sleepy Lizards (Tiliqua rugosa).

    Science.gov (United States)

    Parsons, Sandra K; Bull, C Michael; Gordon, David M

    2015-09-01

    The life cycles of many enteric bacterial species require a transition between two very distinct environments. Their primary habitat is the gastrointestinal tract of the host, while their secondary habitat, during transmission from one host to another, consists of environments external to the host, such as soil, water, and sediments. Consequently, both host and environmental factors shape the genetic structure of enteric bacterial populations. This study examined the distribution of four Salmonella enterica subspecies in a population of sleepy lizards, Tiliqua rugosa, in a semiarid region of South Australia. The lizards living within the 1,920-m by 720-m study site were radio tracked, and their enteric bacteria were sampled at regular intervals throughout their active seasons in the years 2001, 2002, and 2006. Four of the six subspecies of S. enterica were present in this population and were nonrandomly distributed among the lizards. In particular, S. enterica subsp. diarizonae was restricted to lizards living in the most shaded parts of the study site with an overstorey of Casuarina trees. Experiments undertaken to investigate the survival of S. enterica cells under seminatural conditions revealed that cell survival decreased with increased exposure to elevated temperatures and UV light. Among the three S. enterica subspecies tested, S. enterica subsp. diarizonae consistently had an average expected life span that was shorter than that observed for the other two subspecies. There was no indication in the data that there was any competitive dominance hierarchy among the S. enterica subspecies within individual hosts. Thus, the nonrandom distribution of S. enterica subspecies in this population of lizards appears to be driven by their different survival characteristics in the external environment. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  1. Reproducción de la rana Hyla labialis Reproducción del rana Hvla labialis

    Directory of Open Access Journals (Sweden)

    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

  2. Estudio de la hidrólisis del crudo de aceite de palma africana empleando como catalizador la lipasa de la levadura C.rugosa

    Directory of Open Access Journals (Sweden)

    Miguel Molano

    2005-11-01

    Full Text Available En este artículo se presenta el estudio de la hidrólisis del crudo de aceite de palma por medio de la lipasa Candida rugosa. Los factores estudiados en esta investigación fueron el nivel de agitación, el efecto de blanqueo y la cantidad de lipasa. Experimentalmente fueron alcanzados porcentajes de hidrólisis del 79 - 93% en períodos de tiempo de 2 horas y media. Se pudo obtener un incremento de la reacción al aumentar la rotación del agitador al igual que incrementando la concentración de lipasa. Aunque la literatura cita el blanqueado como una ventaja para la hidrólisis enzimática, este procedimiento parece no tener un efecto benéfico en la reacción. / This paper shows the study of the hydrolysis reaction of crude palm oil giving by lipase from Candida rugosa. The studied factors were agitation level, bleaching effect and lipase concentration. Experimentally 79 - 93% hydrolysis were achieved in 2 and a half hour. The reaction rate was increased with the increment of the impeller rotational speed as well as increasing the lipase concentration. Although the literature cites bleaching as a beneficial advantages to enzymatic hydrolysis, this procedure do not have a significant beneficial effect on the reaction.

  3. A survey of blood and other tissue parasites of leopard frogs Rana pipiens in the United States.

    Science.gov (United States)

    Levine, N D; Nye, R R

    1977-01-01

    In a survey of blood and other tissue parasites from 137 leopard frogs, Rana pipiens complex, purchased from 13 commercial vendors in 8 states in the United States, Trypanosoma pipientis was found in 2 R. p. berlandieri, Toxoplasma ranae in 1 R. pipiens, Isospora lieberkuehni in 1 leopard frog, Haemogregarina magna in 44, Lankesterella minima in 3, Leptotheca ohlmacheri in 3 and microfilariae of Foleyella sp. in 6. The report of I. lieberkuehni is presumably a new host record. Haemogregarina temporariae (Nöller,, 1920) nov. comb. is established as a new combination for Nematopsis temporariae.

  4. Effects of two endocrine disruptors Prochloraz and Ethinylestradiol on development of Rana Temporaria

    DEFF Research Database (Denmark)

    Brande-Lavridsen, Nanna; Christensen-Dalsgaard, Jakob; Korsgaard, Bodil

    2009-01-01

    to complete phenotypic sex reversal. The effect of the synthetic estrogen ethinylestradiol and the aromatase-inhibiting fungicide prochloraz on sexual differentiation in Rana temporaria, a species exhibiting natural juvenile hermaphroditism, was investigated. Prochloraz caused an increase in the percentage......  Effects of Prochloraz and Ethinylestradiol on development in Rana temporaria   The ontogeny of most amphibians is characterized by a large degree of sexual plasticity and sex steroids play an important role in the final differentiation of the gonads. One consequence of this plasticity...

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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...

  10. 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....

  11. 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.

  12. Response characteristics of vibration-sensitive neurons in the midbrain of the grassfrog, Rana temporaria

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, J; Jørgensen, M B

    1989-01-01

    European grassfrogs (Rana temporaria) were stimulated with pulsed sinusoidal, vertical vibrations (10-300 Hz) and the responses of 46 single midbrain neurons were recorded in awake, immobilized animals. Most units (40) had simple V-shaped excitatory vibrational tuning curves. The distribution of ...... stimuli probably play a role in communication and detection of predators and the vibration-sensitive midbrain neurons may be involved in the central processing of such behaviorally significant stimuli.......European grassfrogs (Rana temporaria) were stimulated with pulsed sinusoidal, vertical vibrations (10-300 Hz) and the responses of 46 single midbrain neurons were recorded in awake, immobilized animals. Most units (40) had simple V-shaped excitatory vibrational tuning curves. The distribution...... of best frequencies (BF's) was bimodal with peaks at 10 and 100 Hz and the thresholds ranged from 0.02 to 1.28 cm/s2 at the BF. Twenty-three neurons showed phasic-tonic and 11 neurons phasic responses. The dynamic range of seismic intensity for most neurons was 20-30 dB. In contrast to the sharp phase...

  13. 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.

  14. The response characteristics of vibration-sensitive saccular fibers in the grassfrog, Rana temporaria

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, J; Jørgensen, M B

    1988-01-01

    The response characteristics of saccular nerve fibers in European grassfrogs (Rana temporaria) subjected to dorso-ventral, 10-200 Hz sinusoidal vibrations were studied. Only 4 fibers out of a total of 129 did not respond to the vibrations. 70 fibers had an irregular spontaneous activity of 2-48 s...... motion of the otolith relative to the macula is complex. No behavioral role of a vibration receptor has been demonstrated in the grassfrog.(ABSTRACT TRUNCATED AT 250 WORDS)......The response characteristics of saccular nerve fibers in European grassfrogs (Rana temporaria) subjected to dorso-ventral, 10-200 Hz sinusoidal vibrations were studied. Only 4 fibers out of a total of 129 did not respond to the vibrations. 70 fibers had an irregular spontaneous activity of 2......-48 spikes/s. These fibers were very vibration-sensitive. The synchronization thresholds at 10-20 Hz varied from below 0.005 to 0.02 cm/s2. In contrast to earlier results, all these fibers had low-pass characteristics (with respect to acceleration) and responded maximally at 10 and 20 Hz. 55 fibers had...

  15. The in vitro biosynthesis of epitestosterone and testosterone from C19 steroid precursors in the testis of the lizard Tiliqua rugosa

    International Nuclear Information System (INIS)

    Huf, P.A.; Bourne, A.R.; Watson, T.G.

    1989-01-01

    The metabolism of androgens in the testis of the lizard Tiliqua rugosa has been studied in vitro by incubating cellular homogenates with radiolabeled C19-steroid substrates. The identification 17 beta-oxidoreductase and 3 beta-hydroxysteroid dehydrogenase/isomerase activities. Aromatase, 5 alpha-reductase, and 17 alpha/beta-epimerase activities were not detected. The 17 alpha-oxidoreductase activity was temperature dependent (maximal at 32 degrees), while the 17 beta-oxidoreductase activity was temperature independent. Time yield and dual-label studies indicated that testosterone biosynthesis mainly involves the 4-ene pathway (via androstenedione), whereas the formation of epitestosterone uses both the 4-ene and 5-ene (via 5-androstene-3 beta, 17 alpha-diol) pathways. The function of alternative pathways in androgen biosynthesis is discussed, as is the role of temperature in the intratesticular regulation of androgen production

  16. 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)...

  17. 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...

  18. Complex patterns of geographic variation in heat tolerance and Hsp70 expression levels in the common frog Rana temporaria

    DEFF Research Database (Denmark)

    Sørensen, Jesper Givskov; Pekkonen, Minna; Lindgren, Beatrice

    2009-01-01

    1. We tested for geographical variation in heat tolerance and Hsp70 expression levels of Rana temporaria tadpoles along a 1500 km long latitudinal gradient in Sweden.   2. Temperature tolerance of the hatchling tadpoles did not differ among populations, but they tolerated stressful hot temperatur...

  19. 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...

  20. '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.

  1. 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...

  2. 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.

  3. 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

  4. Sound and vibration sensitivity of VIIIth nerve fibers in the grassfrog, Rana temporaria

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, J; Jørgensen, M B

    1996-01-01

    thresholds from 0.02 cm/s2. The sound and vibration sensitivity was compared for each fiber using the offset between the rate-level curves for sound and vibration stimulation as a measure of relative vibration sensitivity. When measured in this way relative vibration sensitivity decreases with frequency from......We have studied the sound and vibration sensitivity of 164 amphibian papilla fibers in the VIIIth nerve of the grassfrog, Rana temporaria. The VIIIth nerve was exposed using a dorsal approach. The frogs were placed in a natural sitting posture and stimulated by free-field sound. Furthermore......, the animals were stimulated with dorso-ventral vibrations, and the sound-induced vertical vibrations in the setup could be canceled by emitting vibrations in antiphase from the vibration exciter. All low-frequency fibers responded to both sound and vibration with sound thresholds from 23 dB SPL and vibration...

  5. Basic response characteristics of auditory nerve fibers in the grassfrog (Rana temporaria)

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, J; Jørgensen, M B; Kanneworff, M

    1998-01-01

    -excitatory suppression (PS) of their spontaneous activity. The duration of PS increased with sound level, also in fibers showing a decrease in firing rate at high intensities. Most fibers showing one-tone suppression did not show PS at their best suppression frequencies. Strong suppression was observed also in very......Responses to free-field sound of 401 fibers from the VIIIth nerve of the grassfrog, Rana temporaria, are described. The spontaneous activities of the fibers ranged from 0 to 75 spikes/s, showing only weak correlation with frequency or sensitivity of the fibers. The highest spontaneous activities...... were approximately twice as high as reported previously for frogs. Best frequencies ranged from 100 to 1600 Hz and thresholds ranged from 21 to 80 dB SPL. The median dynamic range was 20 dB and the slopes of the rate-level curves ranged from 5 to 20 spikes/(s-dB). Most of the units showed post...

  6. 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

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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)

  12. 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.

  13. 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.

  14. Biospectroscopy reveals the effect of varying water quality on tadpole tissues of the common frog (Rana temporaria)

    OpenAIRE

    Strong, Becky; Halsall, Crispin James; Ferenčík, Martin; Jones, Kevin Christopher; Shore, Richard Francis; Martin, Francis Luke

    2016-01-01

    Amphibians are undergoing large population declines in many regions around the world. As environmental pollution from both agricultural and urban sources has been implicated in such declines, there is a need for a biomonitoring approach to study potential impacts on this vulnerable class of organism. This study assessed the use of infrared (IR) spectroscopy as a tool to detect changes in several tissues (liver, muscle, kidney, heart and skin) of late-stage common frog (Rana temporaria) tadpol...

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

    Directory of Open Access Journals (Sweden)

    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.

  16. 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

  17. 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.

  18. Covalent Immobilization of Candida rugosa Lipase at Alkaline pH and Their Application in the Regioselective Deprotection of Per-O-acetylated Thymidine

    Directory of Open Access Journals (Sweden)

    Cintia W. Rivero

    2016-08-01

    Full Text Available Lipase from Candida rugosa (CRL was stabilized at alkaline pH to overcome the inactivation problem and was immobilized for the first time by multipoint covalent attachment on different aldehyde-activated matrices. PEG was used as a stabilizing agent on the activity of CRL. At these conditions, CRL maintained 50% activity at pH 10 after 17 h incubation in the presence of 40% (w/v of PEG, whereas the enzyme without additive was instantaneously inactive after incubation at pH 10. Thus, this enzyme was covalently immobilized at alkaline pH on three aldehyde-activated supports: aldehyde-activated Sepharose, aldehyde-activated Lewatit105 and heterofunctional aldehyde-activated EDA-Sepharose in high overall yields. Heterogeneous stable CRL catalysts at high temperature and solvent were obtained. The aldehyde-activated Sepharose-CRL preparation maintained 70% activity at 50 °C or 30% (v/v acetonitrile after 22 h and exhibited high regioselectivity in the deprotection process of per-O-acetylated thymidine, producing the 3′-OH-5′-OAc-thymidine in 91% yield at pH 5.

  19. Biocatalytic Synthesis of Flavor Ester “Pentyl Valerate” Using Candida rugosa Lipase Immobilized in Microemulsion Based Organogels: Effect of Parameters and Reusability

    Directory of Open Access Journals (Sweden)

    Tripti Raghavendra

    2014-01-01

    Full Text Available Pentyl valerate was synthesized biocatalytically using Candida rugosa lipase (CRL immobilized in microemulsion based organogels (MBGs. The optimum conditions were found to be pH 7.0, temperature of 37°C, ratio of concentration of water to surfactant (Wo of 60, and the surfactant sodium bis-2-(ethylhexylsulfosuccinate (AOT for MBG preparation. Although kinetic studies revealed that the enzyme in free form had high affinity towards substrates (Km = 23.2 mM for pentanol and 76.92 mM for valeric acid whereas, after immobilization, the Km values increased considerably (74.07 mM for pentanol and 83.3 mM for valeric acid resulting in a slower reaction rate, the maximum conversion was much higher in case of immobilized enzyme (~99% as compared to free enzyme (~19%. Simultaneous effects of important parameters were studied using response surface methodology (RSM conjugated with Box-Behnken design (BBD with five variables (process parameters, namely, enzyme concentration, initial water content (Wo, solvent used for MBG preparation, substrate ratio and time, and response as the final product formation, that is, pentyl valerate (%. The MBGs were reused for 10 consecutive cycles for ester synthesis. Efficacy of AOT/isooctane as dehydrating agent for extracting excess water from MBGs was found to exert a positive effect on the esterification reaction.

  20. Conformation and Catalytic Properties Studies of Candida rugosa Lip7 via Enantioselective Esterification of Ibuprofen in Organic Solvents and Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Xiang Li

    2013-01-01

    Full Text Available Enantioselective esterification of ibuprofen was conducted to evaluate the enzyme activity and ees of lipase from Candida rugosa (CRL7 in ten conventional organic solvents and three ionic liquids. Different alcohols were tested for selecting the most suitable acyl acceptor due to the fact that the structure of alcohols (branch and length of carbon chains; location of –OH functional group could affect the enzyme activity and ees. The results of alcohol and solvent selection revealed that 1-isooctanol and isooctane were the best substrate and reaction medium, respectively, because of the highest enzyme activity and ees. Compared with the control, conformational studies via FT-IR indicate that the variations of CRL7’s secondary structure elements are probably responsible for the differences of enzyme activity and ees in the organic solvents and ionic liquids. Moreover, the effects of reaction parameters, such as molar ratio, water content, temperature, and reaction time, in the selected reaction medium, were also examined.

  1. Novel Safranin-Tinted Candida rugosa Lipase Nanoconjugates Reagent for Visualizing Latent Fingerprints on Stainless Steel Knives Immersed in a Natural Outdoor Pond

    Directory of Open Access Journals (Sweden)

    Aida Rasyidah Azman

    2018-05-01

    Full Text Available Waterways are popular locations for the disposition of criminal evidence because the recovery of latent fingerprints from such evidence is difficult. Currently, small particle reagent is a method often used to visualize latent fingerprints containing carcinogenic and hazardous compounds. This study proposes an eco-friendly, safranin-tinted Candida rugosa lipase (triacylglycerol ester hydrolysis EC 3.1.1.3 with functionalized carbon nanotubes (CRL-MWCNTS/GA/SAF as an alternative reagent to the small particle reagent. The CRL-MWCNTS/GA/SAF reagent was compared with the small particle reagent to visualize groomed, full fingerprints deposited on stainless steel knives which were immersed in a natural outdoor pond for 30 days. The quality of visualized fingerprints using the new reagent was similar (modified-Centre for Applied Science and Technology grade: 4; p > 0.05 to small particle reagent, even after 15 days of immersion. Despite the slight decrease in quality of visualized fingerprints using the CRL-MWCNTS/GA/SAF on the last three immersion periods, the fingerprints remained forensically identifiable (modified-Centre for Applied Science and Technology grade: 3. The possible chemical interactions that enabled successful visualization is also discussed. Thus, this novel reagent may provide a relatively greener alternative for the visualization of latent fingerprints on immersed non-porous objects.

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

    Directory of Open Access Journals (Sweden)

    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

  3. 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

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

    Directory of Open Access Journals (Sweden)

    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

  5. 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)

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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)

  11. 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)

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  14. Ranid Herpesvirus 3 and Proliferative Dermatitis in Free-Ranging Wild Common Frogs (Rana Temporaria).

    Science.gov (United States)

    Origgi, F C; Schmidt, B R; Lohmann, P; Otten, P; Akdesir, E; Gaschen, V; Aguilar-Bultet, L; Wahli, T; Sattler, U; Stoffel, M H

    2017-07-01

    Amphibian pathogens are of current interest as contributors to the global decline of amphibians. However, compared with chytrid fungi and ranaviruses, herpesviruses have received relatively little attention. Two ranid herpesviruses have been described: namely, Ranid herpesvirus 1 (RHV1) and Ranid herpesvirus 2 (RHV2). This article describes the discovery and partial characterization of a novel virus tentatively named Ranid herpesvirus 3 (RHV3), a candidate member of the genus Batrachovirus in the family Alloherpesviridae. RHV3 infection in wild common frogs (Rana temporaria) was associated with severe multifocal epidermal hyperplasia, dermal edema, a minor inflammatory response, and variable mucous gland degeneration. Intranuclear inclusions were numerous in the affected epidermis together with unique extracellular aggregates of herpesvirus-like particles. The RHV3-associated skin disease has features similar to those of a condition recognized in European frogs for the last 20 years and whose cause has remained elusive. The genome of RHV3 shares most of the features of the Alloherpesviruses. The characterization of this presumptive pathogen may be of value for amphibian conservation and for a better understanding of the biology of Alloherpesviruses.

  15. Receptor-mediated endocytosis of lysozyme in renal proximal tubules of the frog Rana temporaria

    Directory of Open Access Journals (Sweden)

    E.V. Seliverstova

    2015-04-01

    Full Text Available The mechanism of protein reabsorption in the kidney of lower vertebrates remains insufficiently investigated in spite of raising interest to the amphibian and fish kidneys as a useful model for physiological and pathophysiological examinations. In the present study, we examined the renal tubular uptake and the internalization rote of lysozyme after its intravenous injection in the wintering frog Rana temporaria using immunohisto- and immunocytochemistry and specific markers for some endocytic compartments. The distinct expression of megalin and cubilin in the proximal tubule cells of lysozyme-injected frogs was revealed whereas kidney tissue of control animals showed no positive immunoreactivity. Lysozyme was detected in the apical endocytic compartment of the tubular cells and colocalized with clathrin 10 min after injection. After 20 min, lysozyme was located in the subapical compartment negative to clathrin (endosomes, and intracellular trafficking of lysozyme was coincided with the distribution of megalin and cubilin. However, internalized protein was retained in the endosomes and did not reach lysosomes within 30 min after treatment that may indicate the inhibition of intracellular trafficking in hibernating frogs. For the first time, we provided the evidence that lysozyme is filtered through the glomeruli and absorbed by receptor-mediated clathrin-dependent endocytosis in the frog proximal tubule cells. Thus, the protein uptake in the amphibian mesonephros is mediated by megalin and cubilin that confirms a critical role of endocytic receptors in the renal reabsorption of proteins in amphibians as in mammals.

  16. Mobile phone mast effects on common frog (Rana temporaria) tadpoles: the city turned into a laboratory.

    Science.gov (United States)

    Balmori, Alfonso

    2010-06-01

    An experiment has been made exposing eggs and tadpoles of the common frog (Rana temporaria) to electromagnetic radiation from several mobile (cell) phone antennae located at a distance of 140 meters. The experiment lasted two months, from the egg phase until an advanced phase of tadpole prior to metamorphosis. Measurements of electric field intensity (radiofrequencies and microwaves) in V/m obtained with three different devices were 1.8 to 3.5 V/m. In the exposed group (n = 70), low coordination of movements, an asynchronous growth, resulting in both big and small tadpoles, and a high mortality (90%) was observed. Regarding the control group (n = 70) under the same conditions but inside a Faraday cage, the coordination of movements was normal, the development was synchronous, and a mortality of 4.2% was obtained. These results indicate that radiation emitted by phone masts in a real situation may affect the development and may cause an increase in mortality of exposed tadpoles. This research may have huge implications for the natural world, which is now exposed to high microwave radiation levels from a multitude of phone masts.

  17. 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.

  18. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  1. 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

  2. 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.

  3. Producción de la lipasa LIP2 de Candida rugosa en el sistema Pichia pastoris: caracterización y aplicación en reacciones de síntesis

    OpenAIRE

    Alarcón Vivero, Manuel Rubén

    2008-01-01

    Consultable des del TDX Títol obtingut de la portada digitalitzada Las lipasas son enzima con numerosas aplicaciones en biocatálisis debido a su reacción natural, hidrólisis de enlaces éster, como a su utilización en reacciones de transesterificación y síntesis orgánica. Se destaca como productor de lipasas la levadura Candida rugosa. Existen lipasas comerciales de este microorganismo, pero tienen el inconveniente de ser una mezcla de isoenzimas que hace inviable el proceso de purificac...

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

    Directory of Open Access Journals (Sweden)

    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

  5. Diatomáceas epífitas em Galaxaura rugosa (J. Ellis & Solander J.V. Lamouroux (Rhodophyta no Arquipélago de Fernando de Noronha, PE, Nordeste do Brasil Epiphytic diatoms on Galaxaura rugosa (J. Ellis & Solander J.V. Lamouroux (Rhodophyta in Fernando de Noronha Archipelago, Pernambuco State, Northeast Brazil

    Directory of Open Access Journals (Sweden)

    Manoel Messias da Silva Costa

    2009-09-01

    Full Text Available Exemplares de Galaxaura rugosa (J. Ellis & Solander J.V. Lamouroux foram coletados nos meses de junho/2006 e junho/2007, em três localidades do Arquipélago de Fernando de Noronha (Atalaia, Porto e Cagarras, com o objetivo de identificar a flora das diatomáceas epífitas que habita o talo da alga. Foram identificados 52 táxons distribuídos nas classes: Coscinodiscophyceae (19%, Fragilariophyceae (21% e Bacillariophyceae (60% denotando uma dominância de indivíduos com simetria bilateral, os quais corresponderam a 81% da flora identificada. As seguintes espécies caracterizaram a estrutura florística das diatomáceas, pois foram encontradas em mais de 70% das amostras analisadas: Amphora sp., Biddulphia biddulphiana (J.E. Smith Boyer, Cocconeis scutellum Ehrenberg, Diploneis bombus Ehrenberg, Grammatophora marina (Lyngbye Kützing, Mastogloia binotata (Grunow Cleve, Navicula longa Grunow, Nitzschia sp., Psammodiscus nitidus (Gregory Round in Mann, Rhabdonema adriaticum Kützing, Trachyneis aspera (Ehrenberg Cleve e Tryblionella coarctata (Grunow Mann. A diversidade específica variou entre média à alta, com os menores valores correspondendo aos florescimentos de Amphora sp. (49,3%, Mastogloia binotata (42,1% e Nitzschia sp. (62,5%.Specimens of Galaxaura rugosa (J. Ellis & Solander J.V. Lamouroux were collected in June 2006 and June 2007 at three localities in Fernando de Noronha Archipelago (Atalaia, Porto and Cagarras, aiming to identify the epiphytic diatom flora that inhabits the algae thallus. A total of 52 taxa were identified, distributed in the classes Coscinodiscophyceae (19%, Fragilariophyceae (21% and Bacillariophyceae (60% with 81% dominance of individuals with pinnate symmetry. The following species characterized the floristic diatom structure being considered very frequent: Amphora sp., Biddulphia biddulphiana (J.E. Smith Boyer, Cocconeis scutellum Ehrenberg, Diploneis bombus Ehrenberg, Grammatophora marina (Lyngbye K

  6. 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...

  7. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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.

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

    International Nuclear Information System (INIS)

    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

  19. 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.

  20. 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.

  1. 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.

  2. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  6. 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

    Directory of Open Access Journals (Sweden)

    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.

  7. 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.

  8. Determinação das propriedades catalíticas em meio aquoso e orgânico da lipase de Candida rugosa imobilizada em celulignina quimicamente modificada por carbonildiimidazol Assessment of catalytic properties in aqueous and organic media of lipase from Candida rugosa immobilized on wood cellulignin activated with carbonyldiimidazole

    Directory of Open Access Journals (Sweden)

    Fabrício M. Gomes

    2006-07-01

    Full Text Available Microbial lipase from Candida rugosa was immobilized by covalent binding on wood cellulignin (Eucaliptus grandis chemically modified with carbonyldiimidazole. The immobilized system was fully evaluated in aqueous (olive oil hydrolysis and organic (ester synthesis media. A comparative study between free and immobilized lipase was carried out in terms of pH, temperature and thermal stability. A higher pH value (8.0 was found optimal for the immobilized lipase. The optimal reaction temperature shifted from 37 °C for the free lipase to 45 °C for the immobilized lipase. The pattern of heat stability indicated that the immobilization process tends to stabilize the enzyme. Kinetics tests at 37 °C following the hydrolysis of olive oil obeyed the Michaelis-Menten rate equation. Values for Km = 924.9 mM and Vmax = 198.3 U/mg were lower than for free lipase, suggesting that the affinity towards the substrate changed and the activity of the immobilized lipase decreased during the course of immobilization. The immobilized derivative was also tested in the ester synthesis from several alcohols and carboxylic acids.

  9. 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...

  10. Directionality of auditory nerve fiber responses to pure tone stimuli in the grassfrog, Rana temporaria. II. Spike timing

    DEFF Research Database (Denmark)

    Jørgensen, M B; Christensen-Dalsgaard, J

    1997-01-01

    We studied the directionality of spike timing in the responses of single auditory nerve fibers of the grass frog, Rana temporaria, to tone burst stimulation. Both the latency of the first spike after stimulus onset and the preferred firing phase during the stimulus were studied. In addition, the ...

  11. 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...

  12. Characterization of Physico-Chemical Properties and Antioxidant Capacities of Bioactive Honey Produced from Australian Grown Agastache rugosa and its Correlation with Colour and Poly-Phenol Content

    Directory of Open Access Journals (Sweden)

    Sushil Anand

    2018-01-01

    Full Text Available The antioxidant and antimicrobial components of honey vary based on sourced of nectar. Medicinal plants with the therapeutic value have potential to produce honey with greater bioactivity. The aim of the present study was to characterize the physico-chemical and antioxidant capacities of Agastache honey produced from Agastache rugosa and compare them with other popular commercial honeys sold in Australia. The total phenolics, total flavonoids, moisture content, colour, pH, protein content and antioxidant capacity were evaluated for Agastache, Manuka, Jelly bush, Tea tree, Super manuka and Jarrah honeys. The results reveal that the moisture content ranged from 17–21%, pH ranged from 3.8–4.3 and estimated protein content ranged from 900–2200 µg/g. The DPPH•, ABTS•+, ORAC and FRAP methods were used to measure the antioxidant capacity of the honey samples. The DPPH• % inhibition, ABTS•+, ORAC and FRAP values for Agastache honey were 9.85 (±1.98 µmol TE/g, 26.88 (±0.32 µmol TE/g, 19.78 (±1.1 µmol TE/g and 3.61 (±0.02 µmol TE/g whereas the highest antioxidant capacity values obtained were 18.69 (±0.9 µmol TE/g, 30.72 (±0.27 µmol TE/g, 26.95 (±0.9 µmol TE/g and 3.68 (±0.04 µmol TE/g, respectively. There was a positive correlation between colour, total phenolic content and DPPH• scavenging activity for most of the honeys except Tea tree honey. However, there was no clear correlation with ABTS•+, ORAC and FRAP values. The measured antioxidant capacity of samples varied with the assays used. The DPPH• assay clearly indicated that the phenolic compounds contribute to the scavenging activity of the honeys. Nevertheless, all assays confirm that Agastache honey has significant antioxidant capacity. Therefore, Agastache honey can be important to human nutrition and health.

  13. 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

  14. 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

  15. 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

  16. 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.

  17. 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

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

    Directory of Open Access Journals (Sweden)

    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

  19. Estrutura populacional de Kielmeyera rugosa Choisy (Clusiaceae no Parque Nacional Serra de Itabaiana, Estado do Sergipe - doi: 10.4025/actascibiolsci.v32i2.5127 Population structure of Kielmeyera rugosa Choisy (Clusiaceae at Serra de Itabaiana National Park, Sergipe State - doi: 10.4025/actascibiolsci.v32i2.5127

    Directory of Open Access Journals (Sweden)

    Túlio Vinicius Paes Dantas

    2010-05-01

    Full Text Available Estudos de estrutura de tamanho e de estágios ontogênicos são importantes para se compreender quais fatores influenciam os processos populacionais, a regeneração e a resposta a perturbações de uma população. Este estudo analisou a estrutura de uma população de Kielmeyera rugosa Choisy (Clusiaceae no hábitat de Areias Brancas do Parque Nacional Serra de Itabaiana, Estado de Sergipe. Amostraram-se aleatoriamente 30 parcelas de 20 x 25 m, nas quais se determinou a abundância de indivíduos jovens e adultos, a circunferência do tronco, a altura da copa e o número de caules por planta. A distribuição espacial de jovens e adultos na população é agregada, causada por sua predisposição em formar grupos em locais onde há maior disponibilidade de recursos e condições favoráveis. Outro fator que contribui com a agregação é a dispersão anemocórica da espécie. A população estudada apresentou o maior número de indivíduos nas categorias menores de altura e de DAS, indicando que a população está em crescimento ou em processo de autorregeneração. Há maior número de indivíduos de 2-3 m de altura, o que se deve ao fogo ou corte, eventos que não foram capazes de interromper o processo de recrutamento ou reprodução da espécie na área, pois não ocorreram lacunas nas classes de diâmetro de caule.Studies on structure, size and ontogenic stages are important to understand which factors influence population processes, regeneration and response to disturbances of a population. This study examined the structure of a population of Kielmeyera rugosa Choisy (Clusiaceae in white sands habitat of Serra de Itabaiana, Sergipe State. Thirty 20 x 25 m plots were selected randomly selected, and their abundance of young and adult plants was recorded, as well as trunk circumference, crown height and number of stems per plant. The spatial distribution of young and adult population is aggregated, caused by their predisposition to form

  20. 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.

  1. 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.

  2. 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.

  3. Effect of X-ray irradiation on morphophysiological reactions of epidermal melanophor cells in the larvae of Rana temporaria L

    International Nuclear Information System (INIS)

    Popov, D.V.; Kalistratova, E.N.; Kaluzhina, A.V.

    1982-01-01

    Dynamics of physiological reactions of epidermal melanophors of larvae Rana temporaria L.. adapted to white and black backgrounds and irradiated with a dose of 700 R has been investigated. Ouring the first day after irradiation no day changes of melanophor index characteristic of intact tadpoles were discovered in whitebackground animals; melanophors preserve the aggregation state. Comparison of black background irradiated and control larvae didn't show confident differences in changes of their melanophor indices. Irradiation affects differently epidermal melanophors in the state of pigment dispersion and aggregation. It is suggested that pigment dispersion and aggregation in melanophor is realized at the expense of different cellular structures. It is shown that by the end of the experiment (21-st day) the amount of epidermal melanophor per surface unit is two times larger in black-ground larvae. General biological signaficance of revealed facts from the point of view of ontogenesis evolution is discussed

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

    Directory of Open Access Journals (Sweden)

    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.

  5. Effect of sublethal doses of radiation and cystamine on the dynamics of Rana temporaria L. larvae development

    International Nuclear Information System (INIS)

    Popov, D.V.

    1979-01-01

    The longevity of Rana temporaria L. larvae in the 45th stage of development is studied after irradiation in sublethal doses (10.000-20.000 R) and irradiation with preliminary cystamine protection. It has been shown that the protective effect of cystamine is revealed in partial normalization of the larvae development rate but does not eliminate the typical anomalies of extremity development and does not prolong the time of animal survival. It has been found that LD 50/30 dose for R. temporaria tadpoles in the 45th stage of development is slightly higher than 10.000 R. The selective effect of X-radiation on the formative bonds at cornea induction in Anura larvae is concluded

  6. 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.

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

    Directory of Open Access Journals (Sweden)

    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

  8. 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.

  9. 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

  10. 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.

  11. 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...

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

    Directory of Open Access Journals (Sweden)

    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.

  13. 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.

  14. Geographical variation and sexual differences of body length and age composition in Rana temporaria: the ontogenetic development and phenotypic trends

    Directory of Open Access Journals (Sweden)

    Lyapkov Sergey

    2012-06-01

    Full Text Available The analysis of literature data on the mean values of age and body length of adult individuals of widespread species Rana temporaria from about 70 spatially separated populations, including our published data, was conducted. The evident trend in population mean age increase with the decrease of the of activity season length was revealed as well as the absence of that trend in the mean body length, with the maximal mean value in body length being near central part of the range. Our explanation of non-linear trend in the mean values of body length does not contradict other models of geographic variability explaining the correspondence and discrepance with the Bergman rule. In addition our explanation corresponds to the revealed features of interpopulation variation in growth rate. The revealed trend of variation in the mean body length is resulted from both growth rate decrease and mean age increase with the decrease in the length of activity season. The relatively low mean values of body length in populations from south and southern-west borders of the range are explained not only by low mean age but by lower growth rate despite high length of activity season. The interpopulation variation in body length is determined not only by body length but by age composition differences both between and within population. Therefore, the direction and intensity of sexual differences have not distinct trends, and the correspondence to Rensch rule (in contrast to Bergman rule is rarely observed.

  15. 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

  16. 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.

  17. 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.

  18. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  2. 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

  3. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  5. 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.

  6. Enzymatic Synthesis of Glyserol-Coconut Oil Fatty Acid and Glycerol-Decanoic Acis Ester as Emulsifier and Antimicrobial Agents Using Candida rugosa Lipase EC 3.1.1.3

    Science.gov (United States)

    Handayani, Sri; Putri, Ayu Tanissa Tamara; Setiasih, Siswati; Hudiyono, Sumi

    2018-01-01

    In this research, enzymatic esterification was carried out between glycerol and fatty acid from coconut oil and decanoic acid using n-hexane as solvent. In this reaction Candida rugosa lipase was used as biocatalyst. Optimization esterification reaction was carried out for parameter of the substrate ratio. The mmol ratio between fatty acid and glycerol were used are 1:1, 1:2, 1:3, and 1: 4. The highest conversion percentage obtained at the mole ratio of 1: 4 with the value of 78.5% for the glycerol-decanoic acid ester and 55.4% for the glycerol coconut oil fatty acid ester. Esterification products were characterized by FT-IR. The FT-IR spectrum showed that the ester bond was formed as indicated by the wave number 1750-1739 cm-1. The esterification products were then examined by simple emulsion test and was proved to be an emulsifier. The glycerol-coconut oil fatty acid ester produced higher stability emulsion compare with glycerol decanoic ester. The antimicrobial activity assay using disc diffusion method showed that both glycerol-coconut oil fatty acid ester and glycerol-decanoic ester had the ability inhibiting the growth of Propionibacterium acnes and Staphylococcus epidermidis. Glycerol-decanoic ester shows higher antimicrobial activity than glycerol-coconut oil fatty acid ester.

  7. 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 ...

  8. 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.

  9. 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

  10. 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.

  11. 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

  12. Biospectroscopy reveals the effect of varying water quality on tadpole tissues of the common frog (Rana temporaria).

    Science.gov (United States)

    Strong, Rebecca J; Halsall, Crispin J; Ferenčík, Martin; Jones, Kevin C; Shore, Richard F; Martin, Francis L

    2016-06-01

    Amphibians are undergoing large population declines in many regions around the world. As environmental pollution from both agricultural and urban sources has been implicated in such declines, there is a need for a biomonitoring approach to study potential impacts on this vulnerable class of organism. This study assessed the use of infrared (IR) spectroscopy as a tool to detect changes in several tissues (liver, muscle, kidney, heart and skin) of late-stage common frog (Rana temporaria) tadpoles collected from ponds with differing water quality. Small differences in spectral signatures were revealed between a rural agricultural pond and an urban pond receiving wastewater and landfill run-off; these were limited to the liver and heart, although large differences in body size were apparent, surprisingly with tadpoles from the urban site larger than those from the rural site. Large differences in liver spectra were found between tadpoles from the pesticide and nutrient impacted pond compared to the rural agricultural pond, particularly in regions associated with lipids. Liver mass and hepatosomatic indices were found to be significantly increased in tadpoles from the site impacted by pesticides and trace organic chemicals, suggestive of exposure to environmental contamination. Significant alterations were also found in muscle tissue between tadpoles from these two ponds in regions associated with glycogen, potentially indicative of a stress response. This study highlights the use of IR spectroscopy, a low-cost, rapid and reagent-free technique in the biomonitoring of a class of organisms susceptible to environmental degradation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  18. 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.

  19. 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.

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

    Directory of Open Access Journals (Sweden)

    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

  1. Anatomical evidence for brainstem circuits mediating feeding motor programs in the leopard frog, Rana pipiens.

    Science.gov (United States)

    Anderson, C W

    2001-09-01

    Using injections of small molecular weight fluorescein dextran amines, combined with activity-dependent uptake of sulforhodamine 101 (SR101), brainstem circuits presumed to be involved in feeding motor output were investigated. As has been shown previously in other studies, projections to the cerebellar nuclei were identified from the cerebellar cortex, the trigeminal motor nucleus, and the vestibular nuclei. Results presented here suggest an additional pathway from the hypoglossal motor nuclei to the cerebellar nucleus as well as an afferent projection from the peripheral hypoglossal nerve to the Purkinje cell layer of the cerebellar cortex. Injections in the cerebellar cortex combined with retrograde labeling of the peripheral hypoglossal nerve demonstrate anatomical convergence at the level of the medial reticular formation. This suggests a possible integrative region for afferent feedback from the hypoglossal nerve and information through the Purkinje cell layer of the cerebellar cortex. The activity-dependent uptake of SR101 additionally suggests a reciprocal, polysynaptic pathway between this same area of the medial reticular formation and the trigeminal motor nuclei. The trigeminal motor neurons innervate the m adductor mandibulae, the primary mouth-closing muscle. The SR101 uptake clearly labeled the ventrolateral hypoglossal nuclei, the medial reticular formation, and the Purkinje cell layer of the cerebellar cortex. Unlike retrograde labeling of the peripheral hypoglossal nerve, stimulating the hypoglossal nerve while SR101 was bath-applied labeled trigeminal motor neurons. This, combined with the dextran labeling, suggests a reciprocal connection between the trigeminal motor nuclei and the cerebellar nuclei, as well as the medulla. Taken together, these data are important for understanding the neurophysiological pathways used to coordinate the proper timing of an extremely rapid, goal-directed movement and may prove useful for elucidating some of the

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

    Directory of Open Access Journals (Sweden)

    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

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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

  5. 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

  6. Amphibian population genetics in agricultural landscapes: does viniculture drive the population structuring of the European common frog (Rana temporaria?

    Directory of Open Access Journals (Sweden)

    Patrick P. Lenhardt

    2017-07-01

    Full Text Available Amphibian populations have been declining globally over the past decades. The intensification of agriculture, habitat loss, fragmentation of populations and toxic substances in the environment are considered as driving factors for this decline. Today, about 50% of the area of Germany is used for agriculture and is inhabited by a diverse variety of 20 amphibian species. Of these, 19 are exhibiting declining populations. Due to the protection status of native amphibian species, it is important to evaluate the effect of land use and associated stressors (such as road mortality and pesticide toxicity on the genetic population structure of amphibians in agricultural landscapes. We investigated the effects of viniculture on the genetic differentiation of European common frog (Rana temporaria populations in Southern Palatinate (Germany. We analyzed microsatellite data of ten loci from ten breeding pond populations located within viniculture landscape and in the adjacent forest block and compared these results with a previously developed landscape permeability model. We tested for significant correlation of genetic population differentiation and landscape elements, including land use as well as roads and their associated traffic intensity, to explain the genetic structure in the study area. Genetic differentiation among forest populations was significantly lower (median pairwise FST = 0.0041 at 5.39 km to 0.0159 at 9.40 km distance than between viniculture populations (median pairwise FST = 0.0215 at 2.34 km to 0.0987 at 2.39 km distance. Our analyses rejected isolation by distance based on roads and associated traffic intensity as the sole explanation of the genetic differentiation and suggest that the viniculture landscape has to be considered as a limiting barrier for R. temporaria migration, partially confirming the isolation of breeding ponds predicted by the landscape permeability model. Therefore, arable land may act as a sink habitat

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  8. 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...

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

    International Nuclear Information System (INIS)

    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

  10. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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

  13. 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

  14. 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.

  15. 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.

  16. 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

  17. Molecular basis of pathogenesis of emerging viruses infecting aquatic animals

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    Lang Gui

    2018-01-01

    Full Text Available Aquatic vertebrates are very abundant in the world, and they are of tremendous importance in providing global food security and nutrition. However, emergent and resurgent viruses, such as ranavirus (e.g., Rana grylio virus, RGV and Andriasd avidianus ranavirus, ADRV, herpesvirus (e.g., Carassius carassius herpesvirus, CaHV, reovirus (e.g., grass carp reovirus 109, GCRV-109, Scophthal musmaximus reovirus, SMReV and Micropterus salmoides reovirus, MsReV, and rhabdovirus (e.g., Siniper cachuatsi rhabdovirus, SCRV and Scophthal musmaximus rhabdovirus, SMRV can cause severe diseases in aquaculture animals and wild lower vertebrates, such as frogs, giant salamanders, fish, and so on. Here, we will briefly describe the symptoms produced by the aforementioned viruses and the molecular basis of the virus–host interactions. This manuscript aims to provide an overview of viral diseases in lower vertebrates with an emphasis on visible symptomatic manifestations and pathogenesis.

  18. 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.

  19. The feasibility of using antigens prepared with rough Brucella strains for diagnosis of canine brucellosis Utilidad de los antígenos preparados con cepas rugosas de Brucella en el diagnóstico de brucelosis canina

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    G. I. Escobar

    2010-02-01

    (%P 24 para IELISA-RB51 con 100% de sensibilidad y 98,8% de especificidad. RSAT detectó el 100% de los casos positivos, pero AGID fue menos sensible. Los sueros de los perros tratados con antibióticos tuvieron un %P que correlacionó con la evolución clínica. Los perros presumiblemente infectados con B. suis fueron negativos a todos los ensayos realizados con antígenos de cepas de Brucella rugosas. RSAT es muy sensible como prueba tamiz y los IELISA con antígenos de B. canis, B. ovis y B. abortus RB51 podrían ser usados como confirmatorios ya que han demostrado alta sensibilidad y especificidad.

  20. Osteología, taxonomía y relaciones filogenéticas de las ranas del género Telmatobufo (Leptodactylidae Osteology, taxonomy and phylogenetic relationships of the frog genus Telmatobufo (Leptodactylidae

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    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

  1. 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.

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

    Science.gov (United States)

    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.

  3. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  5. Population and life-stage-specific effects of two herbicide formulations on the aquatic development of European common frogs (Rana temporaria).

    Science.gov (United States)

    Wagner, Norman; Veith, Michael; Lötters, Stefan; Viertel, Bruno

    2017-01-01

    Environmental contamination is suggested to contribute to amphibian population declines. However, the effects of a contaminant on a particular amphibian species can differ among populations. The authors investigated the toxic effects of 2 herbicide formulations on different populations and on representative developmental stages of the European common frog (Rana temporaria). Larvae from forest populations were more sensitive to a commonly used glyphosate-based herbicide compared with individuals from agrarian land. Median lethal concentrations correlated with measured glyphosate levels in the breeding ponds, which may be a sign of evolved tolerances. The reverse result was observed for a less commonly used cycloxydim-based herbicide. Effects of the glyphosate-based herbicide were stronger for earlier larval stages compared with later larval stages. Hence, applications in early spring (when early larvae are present in breeding ponds) pose greater risk concerning acute toxic effects on R. temporaria. With regard to late larval stages, short exposure (96 h) of prometamorphic larvae prolonged time to metamorphosis, but only at the highest test concentration that did not significantly induce mortality. This could be due to impairment of the thyroid axis. Notably, nearly all test concentrations of the 2 herbicides provoked growth retardation. Further research on how evolved or induced tolerances are acquired, actual contamination levels of amphibian habitats, and potential endocrine effects of glyphosate-based herbicides is necessary. Environ Toxicol Chem 2017;36:190-200. © 2016 SETAC. © 2016 SETAC.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Identification of parental chromosomes in hybridogenetic water frog Pelophylax esculentus (Rana esculenta) by genomic in situ hybridization (GISH)

    Czech Academy of Sciences Publication Activity Database

    Zalésna, A.; Choleva, Lukáš; Ogielska, M.; Rábová, Marie; Marec, František; Ráb, Petr

    2010-01-01

    Roč. 18, č. 16 (2010), s. 754-755 ISSN 0967-3849. [19th International Colloquium on animal cytogenetics and gene mapping. 06.06.-09.06.2010, Krakow] Institutional research plan: CEZ:AV0Z50450515; CEZ:AV0Z50070508 Keywords : parental chromosomes * Pelophylax esculentus * hybridization Subject RIV: EB - Genetics ; Molecular Biology

  14. (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) ...

  15. 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

  16. 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

  17. 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.

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    Kerim CICEK

    2011-06-01

    -ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} --> 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 ♂♂, 58 ♀♀, 20 juveniles individuals were analyzed and a total of 2,129 preys 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 preys were Coleoptera (62.8%, Diptera (14.4%, and Hymenoptera (9.8%. It was observed that there was no significant sex- and age-dependent difference in the feeding regime. The species was found to feed less in the breeding period and more in the post-breeding period. It was also striking that there was an increase in the consumption of Coleoptera depending on elevation. In conclusion, the species is an opportunistic and widely-foraging predator that feeds on terrestrial and aquatic insects and its food composition varies by the availability of prey items around it.

  4. Magnetismo Molecular (Molecular Magentism)

    Energy Technology Data Exchange (ETDEWEB)

    Reis, Mario S [Universidade Federal Fluminense, Brasil; Moreira Dos Santos, Antonio F [ORNL

    2010-07-01

    The new synthesis processes in chemistry open a new world of research, new and surprising materials never before found in nature can now be synthesized and, as a wonderful result, observed a series of physical phenomena never before imagined. Among these are many new materials the molecular magnets, the subject of this book and magnetic properties that are often reflections of the quantum behavior of these materials. Aside from the wonderful experience of exploring something new, the theoretical models that describe the behavior these magnetic materials are, in most cases, soluble analytically, which allows us to know in detail the physical mechanisms governing these materials. Still, the academic interest in parallel this subject, these materials have a number of properties that are promising to be used in technological devices, such as in computers quantum magnetic recording, magnetocaloric effect, spintronics and many other devices. This volume will journey through the world of molecular magnets, from the structural description of these materials to state of the art research.

  5. Development of enhanced radioprotectors - Biochemical and molecular genetical approaches on the radioprotective mechanism of natural products

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong Hee; Lee, Eun Ju; Hong, Jung A [Kyunghee University, Seoul (Korea)

    2000-04-01

    To identify radio-protective agent candidate among medicinal plants and to elucidate the mechanism of action of the candidate material by using modern biochemical and molecular biological methods, we screened radio-protective activity among 48 medicinal plants. Seven samples showed above 20% protective activities against oxidative cell damage: Euryale ferox, Glycyrrhiza uralensis, Salvia miltiorrhiza, Eucomia ulmoides, Paeonia suffruticosa, Spirodela polyrrhiza, and Nelumbo nucifera. We also screened for oxidative stress sensitizing activity among other 51 medicinal plants. Among those samples, 11 samples showed good sensitizing effect; Melia azedarach, Agastache rugosa, Catalpa ovata, Prunus persica, Sinomenium acutum, Pulsatilla koreana, Oldenlandia diffusa, Anthriscus sylvestris, Schizandra chinensis, Gleditsia sinensis, and Cridium officinale. We also reported the radio-protective effect of DTT. The treatment of DTT increased cell survival after gamma-irradiation, decreased in the frequencies of micronucleus, and reduction in DNA fragmentation and apoptotic cells. Induction of apoptosis after UV-C irradiation was revealed by the changes in the relative cell death, increase in the relative amount of apoptotic cells, and the induction of DNA fragmentation. 165 refs., 9 figs., 8 tabs. (Author)

  6. Molecular hematology

    National Research Council Canada - National Science Library

    Provan, Drew; Gribben, John

    2010-01-01

    ... The molecular basis of hemophilia, 219 Paul LF Giangrande 4 The genetics of acute myeloid leukemias, 42 Carolyn J Owen & Jude Fitzgibbon 19 The molecular basis of von Willebrand disease, 233 Luciano Baronc...

  7. 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

    Directory of Open Access Journals (Sweden)

    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

  8. Studies on the oligosaccharide heterogeneity of the isoelectric forms of the lower molecular weight acid phosphatase of frog liver.

    Science.gov (United States)

    Kubicz, A; Szalewicz, A; Chrambach, A

    1991-01-01

    1. The lower molecular weight, heterogeneous acid phosphatase (AcPase) from the frog liver (Rana esculenta) containing AcPase I, II, III and IV was separated into enzymatically active components by isoelectric focusing in an immobilized pH gradient. 2. The blotted enzyme bands were characterized by their different binding patterns obtained with the lectins concanavalin A, wheat germ agglutinin (WGA), Lens culinaris hemagglutinin (LcH) and peanut agglutinin (PNA). 3. In situ neuraminidase treatment reduced the staining intensity of some WGA-bands and increased that of PNA-bands. 4. The finding that AcPases I, II, III and IV differ in their carbohydrate chain composition, together with previous results showing different bioactivities of AcPases III and IV, indicates a correlation between the glycosylation state of enzyme forms and their physiological action.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  11. Molecular Diagnostics

    OpenAIRE

    Choe, Hyonmin; Deirmengian, Carl A.; Hickok, Noreen J.; Morrison, Tiffany N.; Tuan, Rocky S.

    2015-01-01

    Orthopaedic infections are complex conditions that require immediate diagnosis and accurate identification of the causative organisms to facilitate appropriate management. Conventional methodologies for diagnosis of these infections sometimes lack accuracy or sufficient rapidity. Current molecular diagnostics are an emerging area of bench-to-bedside research in orthopaedic infections. Examples of promising molecular diagnostics include measurement of a specific biomarker in the synovial fluid...

  12. Molecular genetics

    International Nuclear Information System (INIS)

    Parkinson, D.R.; Krontiris, T.G.

    1986-01-01

    In this chapter the authors review new findings concerning the molecular genetics of malignant melanoma in the context of other information obtained from clinical, epidemiologic, and cytogenetic studies in this malignancy. These new molecular approaches promise to provide a more complete understanding of the mechanisms involved in the development of melanoma, thereby suggesting new methods for its treatment and prevention

  13. Molecular Modeling

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 5. Molecular Modeling: A Powerful Tool for Drug Design and Molecular Docking. Rama Rao Nadendla. General Article Volume 9 Issue 5 May 2004 pp 51-60. Fulltext. Click here to view fulltext PDF. Permanent link:

  14. Molecular geometry

    CERN Document Server

    Rodger, Alison

    1995-01-01

    Molecular Geometry discusses topics relevant to the arrangement of atoms. The book is comprised of seven chapters that tackle several areas of molecular geometry. Chapter 1 reviews the definition and determination of molecular geometry, while Chapter 2 discusses the unified view of stereochemistry and stereochemical changes. Chapter 3 covers the geometry of molecules of second row atoms, and Chapter 4 deals with the main group elements beyond the second row. The book also talks about the complexes of transition metals and f-block elements, and then covers the organometallic compounds and trans

  15. Molecular Electronics

    DEFF Research Database (Denmark)

    Jennum, Karsten Stein

    This thesis includes the synthesis and characterisation of organic compounds designed for molecular electronics. The synthesised organic molecules are mainly based on two motifs, the obigo(phenyleneethynylenes) (OPE)s and tetrathiafulvalene (TTF) as shown below. These two scaffolds (OPE and TTF......) are chemically merged together to form cruciform-like structures that are an essential part of the thesis. The cruciform molecules were subjected to molecular conductance measurements to explore their capability towards single-crystal field-effect transistors (Part 1), molecular wires, and single electron......, however, was obtained by a study of a single molecular transistor. The investigated OPE5-TTF compound was captured in a three-terminal experiment, whereby manipulation of the molecule’s electronic spin was possible in different charge states. Thus, we demonstrated how the cruciform molecules could...

  16. Molecular sciences

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    The research in molecular sciences summarized includes photochemistry, radiation chemistry, geophysics, electromechanics, heavy-element oxidizers , heavy element chemistry collisions, atoms, organic solids. A list of publications is included

  17. Molecular fountain.

    Energy Technology Data Exchange (ETDEWEB)

    Strecker, Kevin E.; Chandler, David W.

    2009-09-01

    A molecular fountain directs slowly moving molecules against gravity to further slow them to translational energies that they can be trapped and studied. If the molecules are initially slow enough they will return some time later to the position from which they were launched. Because this round trip time can be on the order of a second a single molecule can be observed for times sufficient to perform Hz level spectroscopy. The goal of this LDRD proposal was to construct a novel Molecular Fountain apparatus capable of producing dilute samples of molecules at near zero temperatures in well-defined user-selectable, quantum states. The slowly moving molecules used in this research are produced by the previously developed Kinematic Cooling technique, which uses a crossed atomic and molecular beam apparatus to generate single rotational level molecular samples moving slowly in the laboratory reference frame. The Kinematic Cooling technique produces cold molecules from a supersonic molecular beam via single collisions with a supersonic atomic beam. A single collision of an atom with a molecule occurring at the correct energy and relative velocity can cause a small fraction of the molecules to move very slowly vertically against gravity in the laboratory. These slowly moving molecules are captured by an electrostatic hexapole guiding field that both orients and focuses the molecules. The molecules are focused into the ionization region of a time-of-flight mass spectrometer and are ionized by laser radiation. The new molecular fountain apparatus was built utilizing a new design for molecular beam apparatus that has allowed us to miniaturize the apparatus. This new design minimizes the volumes and surface area of the machine allowing smaller pumps to maintain the necessary background pressures needed for these experiments.

  18. Molecular docking.

    Science.gov (United States)

    Morris, Garrett M; Lim-Wilby, Marguerita

    2008-01-01

    Molecular docking is a key tool in structural molecular biology and computer-assisted drug design. The goal of ligand-protein docking is to predict the predominant binding mode(s) of a ligand with a protein of known three-dimensional structure. Successful docking methods search high-dimensional spaces effectively and use a scoring function that correctly ranks candidate dockings. Docking can be used to perform virtual screening on large libraries of compounds, rank the results, and propose structural hypotheses of how the ligands inhibit the target, which is invaluable in lead optimization. The setting up of the input structures for the docking is just as important as the docking itself, and analyzing the results of stochastic search methods can sometimes be unclear. This chapter discusses the background and theory of molecular docking software, and covers the usage of some of the most-cited docking software.

  19. Molecular modeling

    Directory of Open Access Journals (Sweden)

    Aarti Sharma

    2009-01-01

    Full Text Available The use of computational chemistry in the development of novel pharmaceuticals is becoming an increasingly important tool. In the past, drugs were simply screened for effectiveness. The recent advances in computing power and the exponential growth of the knowledge of protein structures have made it possible for organic compounds to be tailored to decrease the harmful side effects and increase the potency. This article provides a detailed description of the techniques employed in molecular modeling. Molecular modeling is a rapidly developing discipline, and has been supported by the dramatic improvements in computer hardware and software in recent years.

  20. Molecular spectroscopy

    International Nuclear Information System (INIS)

    Kokh, Eh.; Zonntag, B.

    1981-01-01

    The latest investigation results on molecular spectroscopy with application of synchrotron radiation in the region of vacuum ultraviolet are generalized. Some results on investigation of excited, superexcited and ionized molecule states with the use of adsorption spectroscopy, photoelectron spectroscopy, by fluorescent and mass-spectrometric methods are considered [ru

  1. Molecular Foundry

    Science.gov (United States)

    . New Study Indicates Greater Capacity for Carbon Storage in the Earth's Subsurface A team of Foundry minerals which make up the dominant clays in the Earth's deep subsurface. Doubling Down on Energy Storage identify molecular components within small volumes of biological samples, such as blood or urine. Industry

  2. Molecular farming

    NARCIS (Netherlands)

    Merck, K.B.; Vereijken, J.M.

    2006-01-01

    Molecular Farming is a new and emerging technology that promises relatively cheap and flexible production of large quantities of pharmaceuticals in genetically modified plants. Many stakeholders are involved in the production of pharmaceuticals in plants, which complicates the discussion on the

  3. Molecular gastronomy

    Science.gov (United States)

    This, Hervé

    2005-01-01

    For centuries, cooks have been applying recipes without looking for the mechanisms of the culinary transformations. A scientific discipline that explores these changes from raw ingredients to eating the final dish, is developing into its own field, termed molecular gastronomy. Here, one of the founders of the discipline discusses its aims and importance.

  4. Molecular Star

    Indian Academy of Sciences (India)

    In molecular self-assembly, molecules put themselves together in a predefined way ... work has been already published in Chemistry- A European Jour- nal in the September ... prevalent in matter ranging from atoms to molecules to biomolecules; it is also ... erate chemical forces are reversible and dynamic in nature mean-.

  5. Molecular ferromagnetism

    International Nuclear Information System (INIS)

    Epstein, A.J.

    1990-01-01

    This past year has been one of substantial advancement in both the physics and chemistry of molecular and polymeric ferromagnets. The specific heat studies of (DMeFc)(TCNE) have revealed a cusp at the three-dimensional ferromagnetic transition temperature with a crossover to primarily 1-D behavior at higher temperatures. This paper discusses these studies

  6. 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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Molecular cloning, sequence analysis and homology modeling of the first caudata amphibian antifreeze-like protein in axolotl (Ambystoma mexicanum).

    Science.gov (United States)

    Zhang, Songyan; Gao, Jiuxiang; Lu, Yiling; Cai, Shasha; Qiao, Xue; Wang, Yipeng; Yu, Haining

    2013-08-01

    Antifreeze proteins (AFPs) refer to a class of polypeptides that are produced by certain vertebrates, plants, fungi, and bacteria and which permit their survival in subzero environments. In this study, we report the molecular cloning, sequence analysis and three-dimensional structure of the axolotl antifreeze-like protein (AFLP) by homology modeling of the first caudate amphibian AFLP. We constructed a full-length spleen cDNA library of axolotl (Ambystoma mexicanum). An EST having highest similarity (∼42%) with freeze-responsive liver protein Li16 from Rana sylvatica was identified, and the full-length cDNA was subsequently obtained by RACE-PCR. The axolotl antifreeze-like protein sequence represents an open reading frame for a putative signal peptide and the mature protein composed of 93 amino acids. The calculated molecular mass and the theoretical isoelectric point (pl) of this mature protein were 10128.6 Da and 8.97, respectively. The molecular characterization of this gene and its deduced protein were further performed by detailed bioinformatics analysis. The three-dimensional structure of current AFLP was predicted by homology modeling, and the conserved residues required for functionality were identified. The homology model constructed could be of use for effective drug design. This is the first report of an antifreeze-like protein identified from a caudate amphibian.

  9. Molecular Modelling

    Directory of Open Access Journals (Sweden)

    Aarti Sharma

    2009-12-01

    Full Text Available

    The use of computational chemistry in the development of novel pharmaceuticals is becoming an increasingly important
    tool. In the past, drugs were simply screened for effectiveness. The recent advances in computing power and
    the exponential growth of the knowledge of protein structures have made it possible for organic compounds to tailored to
    decrease harmful side effects and increase the potency. This article provides a detailed description of the techniques
    employed in molecular modeling. Molecular modelling is a rapidly developing discipline, and has been supported from
    the dramatic improvements in computer hardware and software in recent years.

  10. Molecular scale

    Directory of Open Access Journals (Sweden)

    Christopher H. Childers

    2016-03-01

    Full Text Available This manuscript demonstrates the molecular scale cure rate dependence of di-functional epoxide based thermoset polymers cured with amines. A series of cure heating ramp rates were used to determine the influence of ramp rate on the glass transition temperature (Tg and sub-Tg transitions and the average free volume hole size in these systems. The networks were comprised of 3,3′-diaminodiphenyl sulfone (33DDS and diglycidyl ether of bisphenol F (DGEBF and were cured at ramp rates ranging from 0.5 to 20 °C/min. Differential scanning calorimetry (DSC and NIR spectroscopy were used to explore the cure ramp rate dependence of the polymer network growth, whereas broadband dielectric spectroscopy (BDS and free volume hole size measurements were used to interrogate networks’ molecular level structural variations upon curing at variable heating ramp rates. It was found that although the Tg of the polymer matrices was similar, the NIR and DSC measurements revealed a strong correlation for how these networks grow in relation to the cure heating ramp rate. The free volume analysis and BDS results for the cured samples suggest differences in the molecular architecture of the matrix polymers due to cure heating rate dependence.

  11. Spintronics: The molecular way

    Science.gov (United States)

    Cornia, Andrea; Seneor, Pierre

    2017-05-01

    Molecular spintronics is an interdisciplinary field at the interface between organic spintronics, molecular magnetism, molecular electronics and quantum computing, which is advancing fast and promises large technological payoffs.

  12. Molecular nanomagnets

    CERN Document Server

    Gatteschi, Dante; Villain, Jacques

    2006-01-01

    Nanomagnetism is a rapidly expanding area of research which appears to be able to provide novel applications. Magnetic molecules are at the very bottom of the possible size of nanomagnets and they provide a unique opportunity to observe the coexistence of classical and quantum properties. The discovery in the early 90's that a cluster comprising twelve manganese ions shows hysteresis of molecular origin, and later proved evidence of quantum effects, opened a new research area whichis still flourishing through the collaboration of chemists and physicists. This book is the first attempt to cover

  13. Molecular plasmonics

    CERN Document Server

    Fritzsche, Wolfgang

    2014-01-01

    Adopting a novel approach, this book provides a unique ""molecular perspective"" on plasmonics, concisely presenting the fundamentals and applications in a way suitable for beginners entering this hot field as well as for experienced researchers and practitioners. It begins by introducing readers to the optical effects that occur at the nanoscale and particularly their modification in the presence of biomolecules, followed by a concise yet thorough overview of the different methods for the actual fabrication of nanooptical materials. Further chapters address the relevant nanooptics, as well as

  14. A Model for Taxonomic Work on Homoxenous Coccidia: Redescription, Host Specificity, and Molecular Phylogeny of Eimeria ranae Dobell, 1909, with a Review of Anuran-Host Eimeria (Apicomplexa: Eimeriorina)

    Czech Academy of Sciences Publication Activity Database

    Jirků, Miloslav; Jirků, Milan; Oborník, Miroslav; Lukeš, Julius; Modrý, David

    2009-01-01

    Roč. 56, č. 1 (2009), s. 39-51 ISSN 1066-5234 R&D Projects: GA ČR GA206/03/1544 Institutional research plan: CEZ:AV0Z60220518 Keywords : Amphibia * Anura * experimental infections * metamorphosis * morphotypes * SSU rDNA sequence * tadpoles * ultrastructure Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.355, year: 2009

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

    Directory of Open Access Journals (Sweden)

    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

  16. Morphological and molecular characterization of Seuratascaris numidica (Seurat, 1917) (Ascaridida: Ascarididae).

    Science.gov (United States)

    Chen, Hui-Xia; Zhang, Kuang; Zhang, Lu-Ping; Li, Liang

    2018-03-26

    Seuratascaris numidica (Seurat, 1917) is a specialized nematode species parasitizing amphibians only. In the present study, the detailed morphology of this poorly known species was studied using light and scanning electron microscopy based on the newly material collected from Hoplobatrachus chinensis (Osbeck) (Amphibia: Anura) in China. We found that the relative length of intestinal caecum in our male specimens (representing 68.4-71.1% of oesophageal length) is slighter longer than the previously reported data (not over 60.0% of oesophageal length). Our SEM observations also revealed the presence of ca. 64-76 small conical denticles on each lip. In addition, Angusticaecum wuyiensis Wang, 1981, collected from Rana schmackeri Boettger (Amphibia: Anura) from Wuyi Mountain in Fujian Province, China was considered as a new synonym of S. numidica. The ITS and cox1 sequences of S. numidica were also sequenced for the first time and there is no nucleotide variability detected in both regions. The present supplementary morphological and molecular data (especially the ITS and cox1 sequences) obtained herein is extremely important and useful to determine the morphological variability, population genetics and phylogenetic position of S. numidica in the future.

  17. Progress on molecular imaging

    International Nuclear Information System (INIS)

    Chen Quan; Zhang Yongxue

    2011-01-01

    Molecular imaging is a new era of medical imaging,which can non-invasively monitor biological processes at the cellular and molecular level in vivo, including molecular imaging of nuclear medicine, magnetic resonance molecular imaging, ultrasound molecular imaging,optical molecular imaging and molecular imaging with X-ray. Recently, with the development of multi-subjects amalgamation, multimodal molecular imaging technology has been applied in clinical imaging, such as PET-CT and PET-MRI. We believe that with development of molecular probe and multi-modal imaging, more and more molecular imaging techniques will be applied in clinical diagnosis and treatment. (authors)

  18. Molecular Electronic Terms and Molecular Orbital Configurations.

    Science.gov (United States)

    Mazo, R. M.

    1990-01-01

    Discussed are the molecular electronic terms which can arise from a given electronic configuration. Considered are simple cases, molecular states, direct products, closed shells, and open shells. Two examples are provided. (CW)

  19. An ab initio molecular

    Indian Academy of Sciences (India)

    mechanisms of two molecular crystals: An ab initio molecular dynamics ... for Computation in Molecular and Materials Science and Department of Chemistry, School of ..... NSAF Foundation of National Natural Science Foun- ... Matter 14 2717.

  20. 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.

  1. Molecular HIV screening.

    Science.gov (United States)

    Bourlet, Thomas; Memmi, Meriam; Saoudin, Henia; Pozzetto, Bruno

    2013-09-01

    Nuclear acid testing is more and more used for the diagnosis of infectious diseases. This paper focuses on the use of molecular tools for HIV screening. The term 'screening' will be used under the meaning of first-line HIV molecular techniques performed on a routine basis, which excludes HIV molecular tests designed to confirm or infirm a newly discovered HIV-seropositive patient or other molecular tests performed for the follow-up of HIV-infected patients. The following items are developed successively: i) presentation of the variety of molecular tools used for molecular HIV screening, ii) use of HIV molecular tools for the screening of blood products, iii) use of HIV molecular tools for the screening of organs and tissue from human origin, iv) use of HIV molecular tools in medically assisted procreation and v) use of HIV molecular tools in neonates from HIV-infected mothers.

  2. Understanding molecular structure from molecular mechanics.

    Science.gov (United States)

    Allinger, Norman L

    2011-04-01

    Molecular mechanics gives us a well known model of molecular structure. It is less widely recognized that valence bond theory gives us structures which offer a direct interpretation of molecular mechanics formulations and parameters. The electronic effects well-known in physical organic chemistry can be directly interpreted in terms of valence bond structures, and hence quantitatively calculated and understood. The basic theory is outlined in this paper, and examples of the effects, and their interpretation in illustrative examples is presented.

  3. 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

  4. Molecular sensors and molecular logic gates

    International Nuclear Information System (INIS)

    Georgiev, N.; Bojinov, V.

    2013-01-01

    Full text: The rapid grow of nanotechnology field extended the concept of a macroscopic device to the molecular level. Because of this reason the design and synthesis of (supra)-molecular species capable of mimicking the functions of macroscopic devices are currently of great interest. Molecular devices operate via electronic and/or nuclear rearrangements and, like macroscopic devices, need energy to operate and communicate between their elements. The energy needed to make a device work can be supplied as chemical energy, electrical energy, or light. Luminescence is one of the most useful techniques to monitor the operation of molecular-level devices. This fact determinates the synthesis of novel fluorescence compounds as a considerable and inseparable part of nanoscience development. Further miniaturization of semiconductors in electronic field reaches their limit. Therefore the design and construction of molecular systems capable of performing complex logic functions is of great scientific interest now. In semiconductor devices the logic gates work using binary logic, where the signals are encoded as 0 and 1 (low and high current). This process is executable on molecular level by several ways, but the most common are based on the optical properties of the molecule switches encoding the low and high concentrations of the input guest molecules and the output fluorescent intensities with binary 0 and 1 respectively. The first proposal to execute logic operations at the molecular level was made in 1988, but the field developed only five years later when the analogy between molecular switches and logic gates was experimentally demonstrated by de Silva. There are seven basic logic gates: AND, OR, XOR, NOT, NAND, NOR and XNOR and all of them were achieved by molecules, the fluorescence switching as well. key words: fluorescence, molecular sensors, molecular logic gates

  5. 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 ..•.

  6. Basic molecular spectroscopy

    CERN Document Server

    Gorry, PA

    1985-01-01

    BASIC Molecular Spectroscopy discusses the utilization of the Beginner's All-purpose Symbolic Instruction Code (BASIC) programming language in molecular spectroscopy. The book is comprised of five chapters that provide an introduction to molecular spectroscopy through programs written in BASIC. The coverage of the text includes rotational spectra, vibrational spectra, and Raman and electronic spectra. The book will be of great use to students who are currently taking a course in molecular spectroscopy.

  7. Digitotalar dysmorphism: Molecular elucidation

    African Journals Online (AJOL)

    obtained for molecular studies. Since the distal arthrogryposes (DAs) are genetically heterogeneous, an unbiased approach to mutation ... Diseases and Molecular Medicine, Department of Pathology, Faculty of Health Sciences, University of Cape Town, South Africa, with an interest in molecular genetics of connective ...

  8. Artificial molecular motors

    NARCIS (Netherlands)

    Kassem, Salma; van Leeuwen, Thomas; Lubbe, Anouk S.; Wilson, Miriam R.; Feringa, Ben L.; Leigh, David A.

    2017-01-01

    Motor proteins are nature's solution for directing movement at the molecular level. The field of artificial molecular motors takes inspiration from these tiny but powerful machines. Although directional motion on the nanoscale performed by synthetic molecular machines is a relatively new

  9. Molecular computing origins and promises

    CERN Document Server

    Rambidi, Nicholas G

    2014-01-01

    Molecular Computing explores whether molecular primitives can prove to be real alternatives to contemporary semiconductor means. The text discusses molecular primitives and circuitry for information processing devices.

  10. Molecular similarity measures.

    Science.gov (United States)

    Maggiora, Gerald M; Shanmugasundaram, Veerabahu

    2011-01-01

    Molecular similarity is a pervasive concept in chemistry. It is essential to many aspects of chemical reasoning and analysis and is perhaps the fundamental assumption underlying medicinal chemistry. Dissimilarity, the complement of similarity, also plays a major role in a growing number of applications of molecular diversity in combinatorial chemistry, high-throughput screening, and related fields. How molecular information is represented, called the representation problem, is important to the type of molecular similarity analysis (MSA) that can be carried out in any given situation. In this work, four types of mathematical structure are used to represent molecular information: sets, graphs, vectors, and functions. Molecular similarity is a pairwise relationship that induces structure into sets of molecules, giving rise to the concept of chemical space. Although all three concepts - molecular similarity, molecular representation, and chemical space - are treated in this chapter, the emphasis is on molecular similarity measures. Similarity measures, also called similarity coefficients or indices, are functions that map pairs of compatible molecular representations that are of the same mathematical form into real numbers usually, but not always, lying on the unit interval. This chapter presents a somewhat pedagogical discussion of many types of molecular similarity measures, their strengths and limitations, and their relationship to one another. An expanded account of the material on chemical spaces presented in the first edition of this book is also provided. It includes a discussion of the topography of activity landscapes and the role that activity cliffs in these landscapes play in structure-activity studies.

  11. A morphometric and molecular study of the apoptosis observed on tadpoles' tail explants under the exposition of triiodothyronine in different homeopathic dilutions.

    Science.gov (United States)

    Guedes, José Roberto Pereira; Carrasco, Solange; Ferreira, Cláudia M; Bonamin, Leoni V; Goldenstein-Schainberg, Cláudia; Martins, Vanessa; Capelozzi, Vera L

    2016-08-01

    As a therapeutic system, homeopathy is supported by: i) similitude and experimentation in healthy individuals, ii) potentization. A challenge for researchers consists in looking for signals in water (or vehicle) to explain the storage of information in extremely high dilutions and the transfer of such information to the living systems. Anuran amphibian metamorphosis is controlled by thyroid hormones (TH), including the resorption of the tadpole tail. Apoptosis is a genetically regulated form of cell death that can be triggered by various extracellular and intracellular stimuli resulting in coordinated activation of a family of cysteine proteases called caspases. This study was blind and randomized. It performed in three stages: I) the identification of the most effective T3 homeopathic dilution to induce apoptotic reactions in Rana (Lithobates) catesbeianus tadpole tail explants stimulated by T3 in substantial, II) study of different controls and III) detection in explants under the action of the most effective dilution of T3, as established in Stage I. There was no statistically significant difference between tail macroscopic dimensions between the groups. T3 10cH decreased the expression of caspase 3/7 mRNA, in explants treated with T3 20 nM. The present experiment is in agreement with the hypothesis that T3, at a 10cH homeopathic dilution, changes the metamorphosis molecular network. Copyright © 2016 The Faculty of Homeopathy. Published by Elsevier Ltd. All rights reserved.

  12. Molecular photoionization dynamics

    International Nuclear Information System (INIS)

    Dehmer, J.L.

    1982-01-01

    This program seeks to develop both physical insight and quantitative characterization of molecular photoionization processes. Progress is briefly described, and some publications resulting from the research are listed

  13. Polymer friction Molecular Dynamics

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Samoilov, Vladimir N.; Persson, Bo N. J.

    We present molecular dynamics friction calculations for confined hydrocarbon solids with molecular lengths from 20 to 1400 carbon atoms. Two cases are considered: a) polymer sliding against a hard substrate, and b) polymer sliding on polymer. In the first setup the shear stresses are relatively...... independent of molecular length. For polymer sliding on polymer the friction is significantly larger, and dependent on the molecular chain length. In both cases, the shear stresses are proportional to the squeezing pressure and finite at zero load, indicating an adhesional contribution to the friction force....

  14. 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)

  15. 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)

  16. Making molecular machines work

    NARCIS (Netherlands)

    Browne, Wesley R.; Feringa, Ben L.

    2006-01-01

    In this review we chart recent advances in what is at once an old and very new field of endeavour the achievement of control of motion at the molecular level including solid-state and surface-mounted rotors, and its natural progression to the development of synthetic molecular machines. Besides a

  17. Veterinary Molecular Diagnostics

    NARCIS (Netherlands)

    Roest, H.I.J.; Engelsma, M.Y.; Weesendorp, E.; Bossers, A.; Elbers, A.R.W.

    2017-01-01

    In veterinary molecular diagnostics, samples originating from animals are tested. Developments in the farm animals sector and in our societal attitude towards pet animals have resulted in an increased demand for fast and reliable diagnostic techniques. Molecular diagnostics perfectly matches this

  18. Molecular Beacons in Diagnostics

    OpenAIRE

    Tyagi, Sanjay; Kramer, Fred Russell

    2012-01-01

    Recent technical advances have begun to realize the potential of molecular beacons to test for diverse infections in clinical diagnostic laboratories. These include the ability to test for, and quantify, multiple pathogens in the same clinical sample, and to detect antibiotic resistant strains within hours. The design principles of molecular beacons have also spawned a variety of allied technologies.

  19. Molecular microbial ecology manual

    NARCIS (Netherlands)

    Kowalchuk, G.A.; Bruijn, de F.J.; Head, I.M.; Akkermans, A.D.L.

    2004-01-01

    The field of microbial ecology has been revolutionized in the past two decades by the introduction of molecular methods into the toolbox of the microbial ecologist. This molecular arsenal has helped to unveil the enormity of microbial diversity across the breadth of the earth's ecosystems, and has

  20. Principles of molecular oncology

    National Research Council Canada - National Science Library

    Bronchud, Miguel H

    2008-01-01

    ...-threatening diseases. Many new molecularly targeted diagnostics and therapeutics described in this text, developed based on the rapid growth in our understanding of the molecular basis of cancer, already substantially improve survival of patients with previously lethal malignancies, and also improve quality of life because of fewer toxicities. Clearly re...

  1. Molecular Typing and Differentiation

    Science.gov (United States)

    In this chapter, general background and bench protocols are provided for a number of molecular typing techniques in common use today. Methods for the molecular typing and differentiation of microorganisms began to be widely adopted following the development of the polymerase chai...

  2. Principles of molecular oncology

    National Research Council Canada - National Science Library

    Bronchud, Miguel H; Thomas, E. Donnall; Weatherall, D. J; Crowther, D. G

    2004-01-01

    ...-threatening diseases. Many new molecularly targeted diagnostics and therapeutics described in this text, developed based on the rapid growth in our understanding of the molecular basis of cancer, already substantially improve survival of patients with previously lethal malignancies, and also improve quality of life because of fewer toxicities. Clearly re...

  3. Ionic and Molecular Liquids

    DEFF Research Database (Denmark)

    Chaban, Vitaly V.; Prezhdo, Oleg

    2013-01-01

    applications of RTILs in combination with molecular liquids, concentrating on three significant areas: (1) the use of molecular liquids to decrease the viscosity of RTILs; (2) the role of RTIL micelle formation in water and organic solvents; and (3) the ability of RTILs to adsorb pollutant gases. Current...

  4. Molecular Stirrers in Action

    NARCIS (Netherlands)

    Chen, Jiawen; Kistemaker, Jos C. M.; Robertus, Jort; Feringa, Ben L.

    2014-01-01

    A series of first-generation light-driven molecular motors with rigid substituents of varying length was synthesized to act as "molecular stirrers". Their rotary motion was studied by H-1 NMR and UV-vis absorption spectroscopy in a variety of solvents with different polarity and viscosity.

  5. Molecular subgroups of medulloblastoma

    OpenAIRE

    Northcott, Paul A; Dubuc, Adrian M; Pfister, Stefan; Taylor, Michael D

    2012-01-01

    Recent efforts at stratifying medulloblastomas based on their molecular features have revolutionized our understanding of this morbidity. Collective efforts by multiple independent groups have subdivided medulloblastoma from a single disease into four distinct molecular subgroups characterized by disparate transcriptional signatures, mutational spectra, copy number profiles and, most importantly, clinical features. We present a summary of recent studies that have contributed to our understand...

  6. Theoretical molecular biophysics

    CERN Document Server

    Scherer, Philipp O J

    2017-01-01

    This book gives an introduction to molecular biophysics. It starts from material properties at equilibrium related to polymers, dielectrics and membranes. Electronic spectra are developed for the understanding of elementary dynamic processes in photosynthesis including proton transfer and dynamics of molecular motors. Since the molecular structures of functional groups of bio-systems were resolved, it has become feasible to develop a theory based on the quantum theory and statistical physics with emphasis on the specifics of the high complexity of bio-systems. This introduction to molecular aspects of the field focuses on solvable models. Elementary biological processes provide as special challenge the presence of partial disorder in the structure which does not destroy the basic reproducibility of the processes. Apparently the elementary molecular processes are organized in a way to optimize the efficiency. Learning from nature by means exploring the relation between structure and function may even help to b...

  7. 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.

  8. EDITORIAL: Molecular Imaging Technology

    Science.gov (United States)

    Asai, Keisuke; Okamoto, Koji

    2006-06-01

    'Molecular Imaging Technology' focuses on image-based techniques using nanoscale molecules as sensor probes to measure spatial variations of various species (molecular oxygen, singlet oxygen, carbon dioxide, nitric monoxide, etc) and physical properties (pressure, temperature, skin friction, velocity, mechanical stress, etc). This special feature, starting on page 1237, contains selected papers from The International Workshop on Molecular Imaging for Interdisciplinary Research, sponsored by the Ministry of Education, Culture, Sports, Science and Technology (MEXT) in Japan, which was held at the Sendai Mediatheque, Sendai, Japan, on 8 9 November 2004. The workshop was held as a sequel to the MOSAIC International Workshop that was held in Tokyo in 2003, to summarize the outcome of the 'MOSAIC Project', a five-year interdisciplinary project supported by Techno-Infrastructure Program, the Special Coordination Fund for Promotion of Science Technology to develop molecular sensor technology for aero-thermodynamic research. The workshop focused on molecular imaging technology and its applications to interdisciplinary research areas. More than 110 people attended this workshop from various research fields such as aerospace engineering, automotive engineering, radiotechnology, fluid dynamics, bio-science/engineering and medical engineering. The purpose of this workshop is to stimulate intermixing of these interdisciplinary fields for further development of molecular sensor and imaging technology. It is our pleasure to publish the seven papers selected from our workshop as a special feature in Measurement and Science Technology. We will be happy if this issue inspires people to explore the future direction of molecular imaging technology for interdisciplinary research.

  9. Molecularly Imprinted Membranes

    Science.gov (United States)

    Trotta, Francesco; Biasizzo, Miriam; Caldera, Fabrizio

    2012-01-01

    Although the roots of molecularly imprinted polymers lie in the beginning of 1930s in the past century, they have had an exponential growth only 40–50 years later by the works of Wulff and especially by Mosbach. More recently, it was also proved that molecular imprinted membranes (i.e., polymer thin films) that show recognition properties at molecular level of the template molecule are used in their formation. Different procedures and potential application in separation processes and catalysis are reported. The influences of different parameters on the discrimination abilities are also discussed. PMID:24958291

  10. Photoionization and molecular structure

    International Nuclear Information System (INIS)

    Palma, A.

    1983-01-01

    A presentation is here given of the theoretical work on photoionization and molecular structure carried out by the author and coworkers. The implications of the photoionization process on the molecular geometry are emphasized. In particular, the ionization effect on deep orbitals is considered and it is shown that, contrary to traditional thinking, these orbitals have relevant effects on the molecular geometry. The problem of calculating photoionization relative intensities for the full spectrum is also considered, and the results of the present model are compared with experimental and other theoretical results. (author)

  11. Polypeptides Based Molecular Electronics

    National Research Council Canada - National Science Library

    Lam, Yeng M; Mhaisalkar, Subodh; Li, Lain-Jong; Dravid, Vinayak P; Shekhawat, Gajendra S; Suri, Raman

    2008-01-01

    ... the formation of molecular devices such as transistors, diodes, and sensors. We have designed the peptides, arranged them on substrates using self-assembly, Dip-PEN nanolithography, and also e-beam assisted lithography...

  12. Molecular electronic junction transport

    DEFF Research Database (Denmark)

    Solomon, Gemma C.; Herrmann, Carmen; Ratner, Mark

    2012-01-01

    Whenasinglemolecule,oracollectionofmolecules,isplacedbetween two electrodes and voltage is applied, one has a molecular transport junction. We discuss such junctions, their properties, their description, and some of their applications. The discussion is qualitative rather than quantitative, and f...

  13. Atomic and Molecular Interactions

    International Nuclear Information System (INIS)

    2002-01-01

    The Gordon Research Conference (GRC) on Atomic and Molecular Interactions was held at Roger Williams University, Bristol, RI. Emphasis was placed on current unpublished research and discussion of the future target areas in this field

  14. Noncovalent Molecular Electronics.

    Science.gov (United States)

    Gryn'ova, G; Corminboeuf, C

    2018-05-03

    Molecular electronics covers several distinctly different conducting architectures, including organic semiconductors and single-molecule junctions. The noncovalent interactions, abundant in the former, are also often found in the latter, i.e., the dimer junctions. In the present work, we draw the parallel between the two types of noncovalent molecular electronics for a range of π-conjugated heteroaromatic molecules. In silico modeling allows us to distill the factors that arise from the chemical nature of their building blocks and from their mutual arrangement. We find that the same compounds are consistently the worst and the best performers in the two types of electronic assemblies, emphasizing the universal imprint of the underlying chemistry of the molecular cores on their diverse charge transport characteristics. The interplay between molecular and intermolecular factors creates a spectrum of noncovalent conductive architectures, which can be manipulated using the design strategies based upon the established relationships between chemistry and transport.

  15. The Molecular Foundry (TMF)

    Data.gov (United States)

    Federal Laboratory Consortium — Founded in 2006 by the Department of Energy (DOE), the Molecular Foundry is a critical part of the DOE's National Nanotechnology Initiative, a multi-agency framework...

  16. Molecular ion photofragment spectroscopy

    International Nuclear Information System (INIS)

    Bustamente, S.W.

    1983-11-01

    A new molecular ion photofragment spectrometer is described which features a supersonic molecular beam ion source and a radio frequency octapole ion trap interaction region. This unique combination allows several techniques to be applied to the problem of detecting a photon absorption event of a molecular ion. In particular, it may be possible to obtain low resolution survey spectra of exotic molecular ions by using a direct vibrational predissociation process, or by using other more indirect detection methods. The use of the spectrometer is demonstrated by measuring the lifetime of the O 2 + ( 4 π/sub u/) metastable state which is found to consist of two main components: the 4 π/sub 5/2/ and 4 π/sub -1/2/ spin components having a long lifetime (approx. 129 ms) and the 4 π/sub 3/2/ and 4 π/sub 1/2/ spin components having a short lifetime (approx. 6 ms)

  17. Crossed molecular beams

    International Nuclear Information System (INIS)

    Lee, Y.T.

    1976-01-01

    Research activities with crossed molecular beams at Lawrence Berkeley Laboratory during 1976 are described. Topics covered include: scattering of Ar*, Kr*, with Xe; metastable rare gas interactions, He* + H 2 ; an atomic and molecular halogen beam source; a crossed molecular beam study of the Cl + Br 2 → BrCl + Br reaction; O( 3 P) reaction dynamics, development of the high pressure plasma beam source; energy randomization in the Cl + C 2 H 3 Br → Br + C 2 H 3 Cl reaction; high resolution photoionization studies of NO and ICl; photoionization of (H 2 O)/sub n/ and (NH 3 ) 2 ; photoionization mass spectroscopy of NH 3 + and O 3 + ; photo fragmentation of bromine; and construction of chemiluminescence-laser fluorescence crossed molecular beam machine

  18. Molecular Electronic Shift Registers

    Science.gov (United States)

    Beratan, David N.; Onuchic, Jose N.

    1990-01-01

    Molecular-scale shift registers eventually constructed as parts of high-density integrated memory circuits. In principle, variety of organic molecules makes possible large number of different configurations and modes of operation for such shift-register devices. Several classes of devices and implementations in some specific types of molecules proposed. All based on transfer of electrons or holes along chains of repeating molecular units.

  19. Molecular imaging in oncology

    Energy Technology Data Exchange (ETDEWEB)

    Schober, Otmar; Riemann, Burkhard (eds.) [Universitaetsklinikum Muenster (Germany). Klinik fuer Nuklearmedizin

    2013-02-01

    Considers in detail all aspects of molecular imaging in oncology, ranging from basic research to clinical applications in the era of evidence-based medicine. Examines technological issues and probe design. Discusses preclinical studies in detail, with particular attention to multimodality imaging. Presents current clinical use of PET/CT, SPECT/CT, and optical imagingWritten by acknowledged experts. The impact of molecular imaging on diagnostics, therapy, and follow-up in oncology is increasing significantly. The process of molecular imaging includes key biotarget identification, design of specific molecular imaging probes, and their preclinical evaluation, e.g., in vivo using small animal studies. A multitude of such innovative molecular imaging probes have already entered clinical diagnostics in oncology. There is no doubt that in future the emphasis will be on multimodality imaging in which morphological, functional, and molecular imaging techniques are combined in a single clinical investigation that will optimize diagnostic processes. This handbook addresses all aspects of molecular imaging in oncology, ranging from basic research to clinical applications in the era of evidence-based medicine. The first section is devoted to technology and probe design, and examines a variety of PET and SPECT tracers as well as multimodality probes. Preclinical studies are then discussed in detail, with particular attention to multimodality imaging. In the third section, diverse clinical applications are presented, and the book closes by looking at future challenges. This handbook will be of value to all who are interested in the revolution in diagnostic oncology that is being brought about by molecular imaging.

  20. Human papillomavirus molecular biology.

    Science.gov (United States)

    Harden, Mallory E; Munger, Karl

    Human papillomaviruses are small DNA viruses with a tropism for squamous epithelia. A unique aspect of human papillomavirus molecular biology involves dependence on the differentiation status of the host epithelial cell to complete the viral lifecycle. A small group of these viruses are the etiologic agents of several types of human cancers, including oral and anogenital tract carcinomas. This review focuses on the basic molecular biology of human papillomaviruses. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Molecular imaging in oncology

    International Nuclear Information System (INIS)

    Schober, Otmar; Riemann, Burkhard

    2013-01-01

    Considers in detail all aspects of molecular imaging in oncology, ranging from basic research to clinical applications in the era of evidence-based medicine. Examines technological issues and probe design. Discusses preclinical studies in detail, with particular attention to multimodality imaging. Presents current clinical use of PET/CT, SPECT/CT, and optical imagingWritten by acknowledged experts. The impact of molecular imaging on diagnostics, therapy, and follow-up in oncology is increasing significantly. The process of molecular imaging includes key biotarget identification, design of specific molecular imaging probes, and their preclinical evaluation, e.g., in vivo using small animal studies. A multitude of such innovative molecular imaging probes have already entered clinical diagnostics in oncology. There is no doubt that in future the emphasis will be on multimodality imaging in which morphological, functional, and molecular imaging techniques are combined in a single clinical investigation that will optimize diagnostic processes. This handbook addresses all aspects of molecular imaging in oncology, ranging from basic research to clinical applications in the era of evidence-based medicine. The first section is devoted to technology and probe design, and examines a variety of PET and SPECT tracers as well as multimodality probes. Preclinical studies are then discussed in detail, with particular attention to multimodality imaging. In the third section, diverse clinical applications are presented, and the book closes by looking at future challenges. This handbook will be of value to all who are interested in the revolution in diagnostic oncology that is being brought about by molecular imaging.

  2. Nanoplatform-based molecular imaging

    National Research Council Canada - National Science Library

    Chen, Xiaoyuan

    2011-01-01

    "Nanoplathform-Based Molecular Imaging provides rationale for using nanoparticle-based probes for molecular imaging, then discusses general strategies for this underutilized, yet promising, technology...

  3. Cardiovascular Molecular Imaging

    International Nuclear Information System (INIS)

    Lee, Kyung Han

    2009-01-01

    Molecular imaging strives to visualize processes in living subjects at the molecular level. Monitoring biochemical processes at this level will allow us to directly track biological processes and signaling events that lead to pathophysiological abnormalities, and help make personalized medicine a reality by allowing evaluation of therapeutic efficacies on an individual basis. Although most molecular imaging techniques emerged from the field of oncology, they have now gradually gained acceptance by the cardiovascular community. Hence, the availability of dedicated high-resolution small animal imaging systems and specific targeting imaging probes is now enhancing our understanding of cardiovascular diseases and expediting the development of newer therapies. Examples include imaging approaches to evaluate and track the progress of recent genetic and cellular therapies for treatment of myocardial ischemia. Other areas include in vivo monitoring of such key molecular processes as angiogenesis and apoptosis. Cardiovascular molecular imaging is already an important research tool in preclinical experiments. The challenge that lies ahead is to implement these techniques into the clinics so that they may help fulfill the promise of molecular therapies and personalized medicine, as well as to resolve disappointments and controversies surrounding the field

  4. Molecular toxicity of nanomaterials.

    Science.gov (United States)

    Chang, Xue-Ling; Yang, Sheng-Tao; Xing, Gengmei

    2014-10-01

    With the rapid developments in the fields of nanoscience and nanotechnlogy, more and more nanomaterials and their based consumer products have been used into our daily life. The safety concerns of nanomaterials have been well recognized by the scientific community and the public. Molecular mechanism of interactions between nanomaterials and biosystems is the most essential topic and final core of the biosafety. In the last two decades, nanotoxicology developed very fast and toxicity phenomena of nanomaterials have been reported. To achieve better understanding and detoxication of nanomaterials, thorough studies of nanotoxicity at molecular level are important. The interactions between nanomaterials and biomolecules have been widely investigated as the first step toward the molecular nanotoxicology. The consequences of such interactions have been discussed in the literature. Besides this, the chemical mechanism of nanotoxicology is gaining more attention, which would lead to a better design of nontoxic nanomaterials. In this review, we focus on the molecular nanotoxicology and explore the toxicity of nanomaterials at molecular level. The molecular level studies of nanotoxicology are summarized and the published nanotoxicological data are revisited.

  5. Nanotechnology Review: Molecular Electronics to Molecular Motors

    Science.gov (United States)

    Srivastava, Deepak; Saini, Subhash (Technical Monitor)

    1998-01-01

    Reviewing the status of current approaches and future projections, as already published in scientific journals and books, the talk will summarize the direction in which computational and experimental nanotechnologies are progressing. Examples of nanotechnological approaches to the concepts of design and simulation of carbon nanotube based molecular electronic and mechanical devices will be presented. The concepts of nanotube based gears and motors will be discussed. The above is a non-technical review talk which covers long term precompetitive basic research in already published material that has been presented before many US scientific meeting audiences.

  6. Molecular dewetting on insulators

    International Nuclear Information System (INIS)

    Burke, S A; Topple, J M; Gruetter, P

    2009-01-01

    Recent attention given to the growth and morphology of organic thin films with regard to organic electronics has led to the observation of dewetting (a transition from layer(s) to islands) of molecular deposits in many of these systems. Dewetting is a much studied phenomenon in the formation of polymer and liquid films, but its observation in thin films of the 'small' molecules typical of organic electronics requires additional consideration of the structure of the interface between the molecular film and the substrate. This review covers some key concepts related to dewetting and molecular film growth. In particular, the origins of different growth modes and the thickness dependent interactions which give rise to dewetting are discussed in terms of surface energies and the disjoining pressure. Characteristics of molecular systems which may lead to these conditions, including the formation of metastable interface structures and commensurate-incommensurate phase transitions, are also discussed. Brief descriptions of some experimental techniques which have been used to study molecular dewetting are given as well. Examples of molecule-on-insulator systems which undergo dewetting are described in some detail, specifically perylene derivatives on alkali halides, C 60 on alkali halides, and the technologically important system of pentacene on SiO 2 . These examples point to some possible predicting factors for the occurrence of dewetting, most importantly the formation of an interface layer which differs from the bulk crystal structure. (topical review)

  7. Molecular dewetting on insulators.

    Science.gov (United States)

    Burke, S A; Topple, J M; Grütter, P

    2009-10-21

    Recent attention given to the growth and morphology of organic thin films with regard to organic electronics has led to the observation of dewetting (a transition from layer(s) to islands) of molecular deposits in many of these systems. Dewetting is a much studied phenomenon in the formation of polymer and liquid films, but its observation in thin films of the 'small' molecules typical of organic electronics requires additional consideration of the structure of the interface between the molecular film and the substrate. This review covers some key concepts related to dewetting and molecular film growth. In particular, the origins of different growth modes and the thickness dependent interactions which give rise to dewetting are discussed in terms of surface energies and the disjoining pressure. Characteristics of molecular systems which may lead to these conditions, including the formation of metastable interface structures and commensurate-incommensurate phase transitions, are also discussed. Brief descriptions of some experimental techniques which have been used to study molecular dewetting are given as well. Examples of molecule-on-insulator systems which undergo dewetting are described in some detail, specifically perylene derivatives on alkali halides, C(60) on alkali halides, and the technologically important system of pentacene on SiO(2). These examples point to some possible predicting factors for the occurrence of dewetting, most importantly the formation of an interface layer which differs from the bulk crystal structure.

  8. Phylogenetic molecular function annotation

    International Nuclear Information System (INIS)

    Engelhardt, Barbara E; Jordan, Michael I; Repo, Susanna T; Brenner, Steven E

    2009-01-01

    It is now easier to discover thousands of protein sequences in a new microbial genome than it is to biochemically characterize the specific activity of a single protein of unknown function. The molecular functions of protein sequences have typically been predicted using homology-based computational methods, which rely on the principle that homologous proteins share a similar function. However, some protein families include groups of proteins with different molecular functions. A phylogenetic approach for predicting molecular function (sometimes called 'phylogenomics') is an effective means to predict protein molecular function. These methods incorporate functional evidence from all members of a family that have functional characterizations using the evolutionary history of the protein family to make robust predictions for the uncharacterized proteins. However, they are often difficult to apply on a genome-wide scale because of the time-consuming step of reconstructing the phylogenies of each protein to be annotated. Our automated approach for function annotation using phylogeny, the SIFTER (Statistical Inference of Function Through Evolutionary Relationships) methodology, uses a statistical graphical model to compute the probabilities of molecular functions for unannotated proteins. Our benchmark tests showed that SIFTER provides accurate functional predictions on various protein families, outperforming other available methods.

  9. Molecular MR imaging

    International Nuclear Information System (INIS)

    Fleige, G.; Hamm, B.

    2000-01-01

    Basic medicobiological research in recent years has made rapid advances in the functional understanding of normal and pathological processes down to the molecular level. At the same time, various imaging modalities have developed from the depiction of organs to approaching the depiction of the cellular level and are about to make the visualization of molecular processes an established procedure. Besides other modalities like PET and near-infrared fluorescence, MR imaging offers some promising options for molecular imaging as well as some applications that have already been tested such as the visualization of enzyme activity, the depiction of the expression of certain genes, the visualization of surface receptors, or the specific demonstration of cells involved in the body's immune response. A major advantage of molecular magnetic resonance imaging (mMRI) over other more sensitive modalities is its high spatial resolution. However, the establishment of mMRI crucially relies on further improvements in resolution and the development of molecular markers for improving its sensitivity and specificity. The state of the art of mMRI is presented by giving a survey of the literature on experimental studies and reporting the results our study group obtained during investigation on gliomas. (orig.) [de

  10. Molecularly targeted therapeutic radiopharmaceuticals

    International Nuclear Information System (INIS)

    Saw, M.M.

    2007-01-01

    Full text: It is generally agreed that current focus of nuclear medicine development should be on molecular imaging and therapy. Though, the widespread use of the terminology 'molecular imaging' is quite recent, nuclear medicine has used molecular imaging techniques for more than 20 years ago. A variety of radiopharmaceuticals have been introduced for the internal therapy of malignant and inflammatory lesions in nuclear medicine. In the field of bio/medical imaging, nuclear medicine is one of the disciplines which has the privilege of organized and well developed chemistry/ pharmacy section; radio-chemistry/radiopharmacy. Fundamental principles have been developed more than 40 years ago and advanced research is going well into postgenomic era. The genomic revolution and dramatically increased insight in the molecular mechanisms underlying pathology have led to paradigm shift in drug development. Likewise does in the nuclear medicine. Here, the author will present current clinical and pre-clinical therapeutic radiopharmaceuticals based on molecular targets such as membrane-bound receptors, enzymes, nucleic acids, sodium iodide symporter, etc, in correlation with fundamentals of radiopharmacy. (author)

  11. Evolutionary molecular medicine.

    Science.gov (United States)

    Nesse, Randolph M; Ganten, Detlev; Gregory, T Ryan; Omenn, Gilbert S

    2012-05-01

    Evolution has long provided a foundation for population genetics, but some major advances in evolutionary biology from the twentieth century that provide foundations for evolutionary medicine are only now being applied in molecular medicine. They include the need for both proximate and evolutionary explanations, kin selection, evolutionary models for cooperation, competition between alleles, co-evolution, and new strategies for tracing phylogenies and identifying signals of selection. Recent advances in genomics are transforming evolutionary biology in ways that create even more opportunities for progress at its interfaces with genetics, medicine, and public health. This article reviews 15 evolutionary principles and their applications in molecular medicine in hopes that readers will use them and related principles to speed the development of evolutionary molecular medicine.

  12. [Molecular techniques in mycology].

    Science.gov (United States)

    Rodríguez-Tudela, Juan Luis; Cuesta, Isabel; Gómez-López, Alicia; Alastruey-Izquierdo, Ana; Bernal-Martínez, Leticia; Cuenca-Estrella, Manuel

    2008-11-01

    An increasing number of molecular techniques for the diagnosis of fungal infections have been developed in the last few years, due to the growing prevalence of mycoses and the length of time required for diagnosis when classical microbiological methods are used. These methods are designed to resolve the following aspects of mycological diagnosis: a) Identification of fungi to species level by means of sequencing relevant taxonomic targets; b) early clinical diagnosis of invasive fungal infections; c) detection of molecular mechanisms of resistance to antifungal agents; and d) molecular typing of fungi. Currently, these methods are restricted to highly developed laboratories. However, some of these techniques will probably be available in daily clinical practice in the near future.

  13. Theoretical Molecular Biophysics

    CERN Document Server

    Scherer, Philipp

    2010-01-01

    "Theoretical Molecular Biophysics" is an advanced study book for students, shortly before or after completing undergraduate studies, in physics, chemistry or biology. It provides the tools for an understanding of elementary processes in biology, such as photosynthesis on a molecular level. A basic knowledge in mechanics, electrostatics, quantum theory and statistical physics is desirable. The reader will be exposed to basic concepts in modern biophysics such as entropic forces, phase separation, potentials of mean force, proton and electron transfer, heterogeneous reactions coherent and incoherent energy transfer as well as molecular motors. Basic concepts such as phase transitions of biopolymers, electrostatics, protonation equilibria, ion transport, radiationless transitions as well as energy- and electron transfer are discussed within the frame of simple models.

  14. Molecular Diagnosis of Tuberculosis.

    Science.gov (United States)

    Nurwidya, Fariz; Handayani, Diah; Burhan, Erlina; Yunus, Faisal

    2018-01-01

    Tuberculosis (TB) is one of the leading causes of adult death in the Asia-Pacific Region, including Indonesia. As an infectious disease caused by Mycobacterium tuberculosis (MTB), TB remains a major public health issue especially in developing nations due to the lack of adequate diagnostic testing facilities. Diagnosis of TB has entered an era of molecular detection that provides faster and more cost-effective methods to diagnose and confirm drug resistance in TB cases, meanwhile, diagnosis by conventional culture systems requires several weeks. New advances in the molecular detection of TB, including the faster and simpler nucleic acid amplification test (NAAT) and whole-genome sequencing (WGS), have resulted in a shorter time for diagnosis and, therefore, faster TB treatments. In this review, we explored the current findings on molecular diagnosis of TB and drug-resistant TB to see how this advancement could be integrated into public health systems in order to control TB.

  15. Synergetics of molecular systems

    CERN Document Server

    Lupichev, Lev N; Kadantsev, Vasiliy N

    2014-01-01

    Synergetics is the quantitative study of multicomponent systems that exhibit nonlinear dynamics and cooperativity. This book specifically considers basic models of the nonlinear dynamics of molecular systems and discusses relevant applications in biological physics and the polymer sciences.Emphasis is placed on specific solutions to the dynamical equations that correspond to the coherent formation of spatial-temporal structures, such as solitons, kinks and breathers, in particular. The emergence of these patterns in molecular structures provides a variety of information on their structural pro

  16. Molecular environmental geochemistry

    Science.gov (United States)

    O'Day, Peggy A.

    1999-05-01

    The chemistry, mobility, and bioavailability of contaminant species in the natural environment are controlled by reactions that occur in and among solid, aqueous, and gas phases. These reactions are varied and complex, involving changes in chemical form and mass transfer among inorganic, organic, and biochemical species. The field of molecular environmental geochemistry seeks to apply spectroscopic and microscopic probes to the mechanistic understanding of environmentally relevant chemical processes, particularly those involving contaminants and Earth materials. In general, empirical geochemical models have been shown to lack uniqueness and adequate predictive capability, even in relatively simple systems. Molecular geochemical tools, when coupled with macroscopic measurements, can provide the level of chemical detail required for the credible extrapolation of contaminant reactivity and bioavailability over ranges of temperature, pressure, and composition. This review focuses on recent advances in the understanding of molecular chemistry and reaction mechanisms at mineral surfaces and mineral-fluid interfaces spurred by the application of new spectroscopies and microscopies. These methods, such as synchrotron X-ray absorption and scattering techniques, vibrational and resonance spectroscopies, and scanning probe microscopies, provide direct chemical information that can elucidate molecular mechanisms, including element speciation, ligand coordination and oxidation state, structural arrangement and crystallinity on different scales, and physical morphology and topography of surfaces. Nonvacuum techniques that allow examination of reactions in situ (i.e., with water or fluids present) and in real time provide direct links between molecular structure and reactivity and measurements of kinetic rates or thermodynamic properties. Applications of these diverse probes to laboratory model systems have provided fundamental insight into inorganic and organic reactions at

  17. Molecular cardiovascular imaging

    International Nuclear Information System (INIS)

    Schaefers, M.

    2007-01-01

    Although huge and long-lasting research efforts have been spent on the development of new diagnostic techniques investigating cardiovascular diseases, still fundamental challenges exist; the main challenge being the diagnosis of a suspected or known coronary artery disease or its consequences (myocardial infarction, heart failure etc.). Beside morphological techniques, functional imaging modalities are available in clinical diagnostic algorithms, whereas molecular cardiovascular imaging techniques are still under development. This review summarizes clinical-diagnostical challenges of modern cardiovascular medicine as well as the potential of new molecular imaging techniques to face these. (orig.)

  18. Targeted molecular imaging

    International Nuclear Information System (INIS)

    Kim, E. Edmund

    2003-01-01

    Molecular imaging aims to visualize the cellular and molecular processes occurring in living tissues, and for the imaging of specific molecules in vivo, the development of reporter probes and dedicated imaging equipment is most important. Reporter genes can be used to monitor the delivery and magnitude of therapeutic gene transfer, and the time variation involved. Imaging technologies such as micro-PET, SPECT, MRI and CT, as well as optical imaging systems, are able to non-invasively detect, measure, and report the simultaneous expression of multiple meaningful genes. It is believed that recent advances in reporter probes, imaging technologies and gene transfer strategies will enhance the effectiveness of gene therapy trials

  19. Substructured multibody molecular dynamics.

    Energy Technology Data Exchange (ETDEWEB)

    Grest, Gary Stephen; Stevens, Mark Jackson; Plimpton, Steven James; Woolf, Thomas B. (Johns Hopkins University, Baltimore, MD); Lehoucq, Richard B.; Crozier, Paul Stewart; Ismail, Ahmed E.; Mukherjee, Rudranarayan M. (Rensselaer Polytechnic Institute, Troy, NY); Draganescu, Andrei I.

    2006-11-01

    We have enhanced our parallel molecular dynamics (MD) simulation software LAMMPS (Large-scale Atomic/Molecular Massively Parallel Simulator, lammps.sandia.gov) to include many new features for accelerated simulation including articulated rigid body dynamics via coupling to the Rensselaer Polytechnic Institute code POEMS (Parallelizable Open-source Efficient Multibody Software). We use new features of the LAMMPS software package to investigate rhodopsin photoisomerization, and water model surface tension and capillary waves at the vapor-liquid interface. Finally, we motivate the recipes of MD for practitioners and researchers in numerical analysis and computational mechanics.

  20. Open source molecular modeling.

    Science.gov (United States)

    Pirhadi, Somayeh; Sunseri, Jocelyn; Koes, David Ryan

    2016-09-01

    The success of molecular modeling and computational chemistry efforts are, by definition, dependent on quality software applications. Open source software development provides many advantages to users of modeling applications, not the least of which is that the software is free and completely extendable. In this review we categorize, enumerate, and describe available open source software packages for molecular modeling and computational chemistry. An updated online version of this catalog can be found at https://opensourcemolecularmodeling.github.io. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  1. Molecular epidemiology of Blastocystis

    Directory of Open Access Journals (Sweden)

    Fadime Eroğlu

    2015-12-01

    Full Text Available Blastocystis pathogenicity and classification was newly illuminated with molecular genetic studies and recently the parasite was found in the focus of many researchers. Several molecular methods such as; polymerase chain reaction (PCR, PCR-restriction fragment length polymorphism, random amplified polymorphic DNA, real-time polymerase chain reaction and DNA sequencing analyses can be used in genotyping of Blastocystis. Blastocystis parasites may cause diarrhea, abdominal pain, bloating, gas, irritability, anorexia, cramps, vomiting, dehydration, insomnia, nausea, loss of appetite, weight loss, fatigue symptoms and also could be asymptomatic cases. In this review, it was aimed to summarize the associations between Blastocystis subtypes and pathogenicity.

  2. Valency and molecular structure

    CERN Document Server

    Cartmell, E

    1977-01-01

    Valency and Molecular Structure, Fourth Edition provides a comprehensive historical background and experimental foundations of theories and methods relating to valency and molecular structures. In this edition, the chapter on Bohr theory has been removed while some sections, such as structures of crystalline solids, have been expanded. Details of structures have also been revised and extended using the best available values for bond lengths and bond angles. Recent developments are mostly noted in the chapter on complex compounds, while a new chapter has been added to serve as an introduction t

  3. Ionic and Molecular Liquids

    DEFF Research Database (Denmark)

    Chaban, Vitaly V.; Prezhdo, Oleg

    2013-01-01

    Because of their outstanding versatility, room-temperature ionic liquids (RTILs) are utilized in an ever increasing number of novel and fascinating applications, making them the Holy Grail of modern materials science. In this Perspective, we address the fundamental research and prospective...... applications of RTILs in combination with molecular liquids, concentrating on three significant areas: (1) the use of molecular liquids to decrease the viscosity of RTILs; (2) the role of RTIL micelle formation in water and organic solvents; and (3) the ability of RTILs to adsorb pollutant gases. Current...

  4. Molecular confocal laser endomicroscopy

    DEFF Research Database (Denmark)

    Karstensen, John Gásdal; Klausen, Pia Helene; Saftoiu, Adrian

    2014-01-01

    While flexible endoscopy is essential for macroscopic evaluation, confocal laser endomicroscopy (CLE) has recently emerged as an endoscopic method enabling visualization at a cellular level. Two systems are currently available, one based on miniprobes that can be inserted via a conventional...... during on-going endoscopy), a novel world of molecular evaluation opens up. The method of molecular CLE could potentially be used for estimating the expression of important receptors in carcinomas, subsequently resulting in immediate individualization of treatment regimens, but also for improving...

  5. Molecular theory of capillarity

    CERN Document Server

    Rowlinson, J S

    2002-01-01

    History of thought on molecular origins of surface phenomena offers a critical and detailed examination and assessment of modern theories, focusing on statistical mechanics and application of results in mean-field approximation to model systems. Emphasis on liquid-gas surface, with a focus on liquid-liquid surfaces in the final chapters. 1989 edition.

  6. Reviews: The Molecular Animator.

    Science.gov (United States)

    Journal of Chemical Education, 1987

    1987-01-01

    Provided is a review of a chemical software package. The package makes possible an instructional technique that is not effective by any other means, namely the ability to view molecular shapes in three dimensions. The program can be used with either IBM or Apple hardware. (RH)

  7. [Towards a molecular psychiatry].

    Science.gov (United States)

    de la Fuente, J R

    1988-06-01

    Recent research data from psychopharmacology, brain imaging and molecular genetics support the notion of a new psychiatric frontier: that of molecular psychiatry. Identification of different subtypes of neurotransmitter receptors and their changes in density and sensitivity in response to endogenous ligands and/or psychotropic drugs may account for the clinical expression of various behavioral phenomena, including some psychiatric disorders. Brain imaging, in particular positron-emission tomographic evaluations, are likely to change psychiatric nosology. New diagnostic elements derived from these scanners will allow to associate psychotic states to neuroreceptor changes. Molecular genetics has shown that bipolar affective disorder can be caused by a single gene. A strong linkage seems to exist between a gene locus on chromosome 11 and bipolar illness. An amyloid gene located on chromosome 21 has also been shown to be strongly related to familial Alzheimer's disease. While genetic heterogeneity limits the screening value of these findings, the powerful techniques of molecular biology have entered the field of psychiatry. Ethical issues regarding DNA immortality, gene cloning and gene therapy will strengthen this relationship.

  8. Molecular studies of achondroplasia

    Directory of Open Access Journals (Sweden)

    Nahar Risha

    2009-01-01

    Full Text Available Background: Achondroplasia (ACH is the most frequent form of short-limbed dwarfi sm, caused by mutations in the FGFR3 gene. It follows an autosomal dominant inheritance, though most cases are sporadic. The molecular techniques are the only available methods to confi rm the diagnosis of a skeletal dysplasia. Clinical and radiological features are only suggestive and not confi rmatory. The present study was conducted to fi nd out how often the clinical diagnosis of achondroplasia is verifi ed on molecular studies. Materials and Methods: From 1998 through 2007, we carried out molecular analysis for the two common mutations in the FGFR3 gene in 130 cases clinically suspected to have ACH. Results: A diagnostic mutation was identifi ed in 53 (40.8% cases. The common mutation (1138G>A was present in 50 (94.7% of the positive cases, while the rare 1138 G>C substitution was found in three (5.3%. Conclusion: This study shows that confi rmation of clinical diagnosis of ACH by molecular genetic testing is essential to distinguish it from other skeletal dysplasias, to plan therapeutic options, and to offer genetic counseling. Management (medical and surgical in patients confi rmed to have ACH, is briefl y discussed.

  9. Molecular diagnosis and immunotherapy.

    Science.gov (United States)

    Sastre, Joaquín; Sastre-Ibañez, Marina

    2016-12-01

    To describe recent insights into how molecular diagnosis can improve indication and selection of suitable allergens for specific immunotherapy and increase the safety of this therapy. As specific allergen immunotherapy targets specific allergens, identification of the disease-eliciting allergen is a prerequisite for accurate prescription of treatment. In areas of complex sensitization to aeroallergens or in cases of hymenoptera venom allergy, the use of molecular diagnosis has demonstrated that it may lead to a change in indication and selection of allergens for immunotherapy in a large proportion of patients when compared with diagnosis based on skin prick testing and/or specific IgE determination with commercial extracts. These changes in immunotherapy prescription aided by molecular diagnosis have been demonstrated to be cost-effective in some scenarios. Certain patterns of sensitization to grass or olive pollen and bee allergens may identify patients with higher risk of adverse reaction during immunotherapy. Molecular diagnosis, when used with other tools and patients' clinical records, can help clinicians better to select the most appropriate patients and allergens for specific immunotherapy and, in some cases, predict the risk of adverse reactions. The pattern of sensitization to allergens could potentially predict the efficacy of allergen immunotherapy provided that these immunotherapy products contain a sufficient amount of these allergens. Nevertheless, multiplex assay remains a third-level approach, not to be used as screening method in current practice.

  10. Isotopes in molecular biology

    International Nuclear Information System (INIS)

    Goldfarb, P.S.G.

    1988-01-01

    The use of radioisotopes in molecular biology, with particular reference to the structure and functions of DNA, RNA and the cellular synthesis of proteins, is discussed. The use of labelled DNA and RNA in diagnostic techniques is presented. (U.K.)

  11. Biophysics of molecular gastronomy.

    Science.gov (United States)

    Brenner, Michael P; Sörensen, Pia M

    2015-03-26

    Chefs and scientists exploring biophysical processes have given rise to molecular gastronomy. In this Commentary, we describe how a scientific understanding of recipes and techniques facilitates the development of new textures and expands the flavor palette. The new dishes that result engage our senses in unexpected ways. PAPERCLIP. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Molecular gastronomy in Spain

    DEFF Research Database (Denmark)

    García-Segovia, P.; Garrido, M. D.; Vercet, A.

    2014-01-01

    Beyond the overwhelming international success of Ferrán Adria, Spain has been one of the countries with a more active implication in molecular gastronomy as a scientific discipline but also in the use of ingredients, technologies, and equipment from the scientific and technological universe...... with scientists for facing the future of Spanish gastronomy....

  13. Molecular Mechanisms of Preeclampsia

    Directory of Open Access Journals (Sweden)

    N. Vitoratos

    2012-01-01

    Full Text Available Preeclampsia is one of the leading causes of maternal morbidity/mortality. The pathogenesis of preeclampsia is still under investigation. The aim of this paper is to present the molecular mechanisms implicating in the pathway leading to preeclampsia.

  14. Molecular MR Imaging Probes

    OpenAIRE

    MAHMOOD, UMAR; JOSEPHSON, LEE

    2005-01-01

    Magnetic resonance imaging (MRI) has been successfully applied to many of the applications of molecular imaging. This review discusses by example some of the advances in areas such as multimodality MR-optical agents, receptor imaging, apoptosis imaging, angiogenesis imaging, noninvasive cell tracking, and imaging of MR marker genes.

  15. Molecular dynamics for fermions

    International Nuclear Information System (INIS)

    Feldmeier, H.; Schnack, J.

    2000-02-01

    The time-dependent variational principle for many-body trial states is used to discuss the relation between the approaches of different molecular dynamics models to describe indistinguishable fermions. Early attempts to include effects of the Pauli principle by means of nonlocal potentials as well as more recent models which work with antisymmetrized many-body states are reviewed under these premises. (orig.)

  16. Nanopatterning by molecular polygons.

    Science.gov (United States)

    Jester, Stefan-S; Sigmund, Eva; Höger, Sigurd

    2011-07-27

    Molecular polygons with three to six sides and binary mixtures thereof form long-range ordered patterns at the TCB/HOPG interface. This includes also the 2D crystallization of pentagons. The results provide an insight into how the symmetry of molecules is translated into periodic structures.

  17. Molecular radio-oncology

    Energy Technology Data Exchange (ETDEWEB)

    Baumann, Michael; Krause, Mechthild; Cordes, Nils (eds.) [Technische Univ. Dresden (Germany). Faculty of Medicine and University Hospital

    2016-07-01

    This book concisely reviews our current understanding of hypoxia, molecular targeting, DNA repair, cancer stem cells, and tumor pathophysiology, while also discussing novel strategies for putting these findings into practice in daily clinical routine. Radiotherapy is an important part of modern multimodal cancer treatment, and the past several years have witnessed not only substantial improvements in radiation techniques and the use of new beam qualities, but also major strides in our understanding of molecular tumor biology and tumor radiation response. Against this backdrop, the book highlights recent efforts to identify reasonable and clinically applicable biomarkers using broad-spectrum tissue microarrays and high-throughput systems biology approaches like genomics and epigenomics. In particular, it describes in detail how such molecular information is now being exploited for diagnostic imaging and imaging throughout treatment using the example of positron emission tomography. By discussing all these issues in the context of modern radiation oncology, the book provides a broad, up-to-date overview of the molecular aspects of radiation oncology that will hopefully foster its further optimization.

  18. Molecular radio-oncology

    International Nuclear Information System (INIS)

    Baumann, Michael; Krause, Mechthild; Cordes, Nils

    2016-01-01

    This book concisely reviews our current understanding of hypoxia, molecular targeting, DNA repair, cancer stem cells, and tumor pathophysiology, while also discussing novel strategies for putting these findings into practice in daily clinical routine. Radiotherapy is an important part of modern multimodal cancer treatment, and the past several years have witnessed not only substantial improvements in radiation techniques and the use of new beam qualities, but also major strides in our understanding of molecular tumor biology and tumor radiation response. Against this backdrop, the book highlights recent efforts to identify reasonable and clinically applicable biomarkers using broad-spectrum tissue microarrays and high-throughput systems biology approaches like genomics and epigenomics. In particular, it describes in detail how such molecular information is now being exploited for diagnostic imaging and imaging throughout treatment using the example of positron emission tomography. By discussing all these issues in the context of modern radiation oncology, the book provides a broad, up-to-date overview of the molecular aspects of radiation oncology that will hopefully foster its further optimization.

  19. Molecular Pathogenesis of Spondyloarthritis

    DEFF Research Database (Denmark)

    Carlsen, Thomas Gelsing

    This dissertation includes a presentation of knowledge on the molecular pathogenesis of spondyloarthritis achieved through a PhD programme at Aalborg University from 1.12.2011 - 1.12.2014. Work was carried out in the Laboratory of Medical Mass Spectrometry, headed by: Professor Svend Birkelund...

  20. Molecular-nuclear transitions

    International Nuclear Information System (INIS)

    Belyaev, V.B.; Miller, M.B.

    2007-01-01

    Full text: The spectra in some light nuclei have one interesting property. For example, in the closed vicinity of some resonance states of such nuclei as 5 He, 8 Be, 18 F, 18 Ne the thresholds exist for two- or three-body decay of those nuclei. Let us consider the lightest of the above nuclei, 5 He. The energy threshold for 5 He > d+t decay is ∼50 keV lower than the energy of 3/2 + state of 5 He nucleus. However, due to a rather large width of this state, ∼70 keV, the nuclear capture of deuterons by tritons in dtm-molecule is highly enhanced in comparison with the process of dd capture in the ddm molecule. The physical reason for the enhancement of the probability of the capture into the resonant state can be associated with a long tail of wave function of the resonant state and, accordingly, with the large value of the overlap integral determining in general the probability of the transition between two systems. Thus, one can expect the enhancement of the molecular-nuclear transitions, and this was indeed observed experimentally for the case of dtm molecule. Now, let us consider some other molecular-nuclear combinations: 18 Ne - H 2 O, 18 F - 17 OH, and 8 Be - 6 LiD molecule. With the high accuracy the energies of the above molecular systems coincide with the energies of the resonant states in the appropriate nuclei. Due to the uncertainty in the experimental nuclear data it is not known at present whether the energies of these thresholds are lower or higher of the corresponding energies of the nuclear resonances. Let us assume that the molecular energy is few keV over the energy of the nuclear resonance. Then, we will deal with a very interesting phenomenon: the molecular-nuclear complex constitutes a two level system, which in some sense is analogous to the two-level atomic system, as in a laser. The crucial difference between this one and the two-level atomic systems consists in a fact that in the molecular-nuclear case no special procedure of pumping up

  1. Molecular imaging in oncology

    International Nuclear Information System (INIS)

    Weber, W.A.

    2007-01-01

    Molecular imaging is generally defined as noninvasive and quantitative imaging of targeted macromolecules and biological processes in living organisms. A characteristic of molecular imaging is the ability to perform repeated studies and assess changes in biological processes over time. Thus molecular imaging lends itself well for monitoring the effectiveness of tumor therapy. In animal models a variety of techniques can be used for molecular imaging. These include optical imaging (bioluminescence and fluorescence imaging), magnetic resonance imaging (MRI) and nuclear medicine techniques. In the clinical setting, however, nuclear medicine techniques predominate, because so far only radioactive tracers provide the necessary sensitivity to study expression and function of macromolecules non-invasively in patients. Nuclear medicine techniques allows to study a variety of biological processes in patients. These include the expression of various receptors (estrogen, androgen, somatostatin receptors and integrins). In addition, tracers are available to study tumor cell proliferation and hypoxia. The by far most commonly used molecular imaging technique in oncology is, however, positron emission tomography (PET) with the glucose analog [ 18 F]fluorodeoxyglucose (FDG-PET). FDG-PET permits non-invasive quantitative assessment of the accelerated exogenous glucose use of malignant tumors. Numerous studies have now shown that reduction of tumor FDG-uptake during therapy allows early prediction of tumor response and patient survival. Clinical studies are currently underway to determine whether FDG-PET can be used to individualize tumor therapy by signaling early in the course of therapy the need for therapeutic adjustments in patients with likely non-responding tumors. (orig.)

  2. Conformation analysis of trehalose. Molecular dynamics simulation and molecular mechanics

    International Nuclear Information System (INIS)

    Donnamaira, M.C.; Howard, E.I.; Grigera, J.R.

    1992-09-01

    Conformational analysis of the disaccharide trehalose is done by molecular dynamics and molecular mechanics. In spite of the different force fields used in each case, comparison between the molecular dynamics trajectories of the torsional angles of glycosidic linkage and energy conformational map shows a good agreement between both methods. By molecular dynamics it is observed a moderate mobility of the glycosidic linkage. The demands of computer time is comparable in both cases. (author). 6 refs, 4 figs

  3. Topology in Molecular Biology

    CERN Document Server

    Monastyrsky, Michail Ilych

    2007-01-01

    The book presents a class of new results in molecular biology for which topological methods and ideas are important. These include: the large-scale conformation properties of DNA; computational methods (Monte Carlo) allowing the simulation of large-scale properties of DNA; the tangle model of DNA recombination and other applications of Knot theory; dynamics of supercoiled DNA and biocatalitic properties of DNA; the structure of proteins; and other very recent problems in molecular biology. The text also provides a short course of modern topology intended for the broad audience of biologists and physicists. The authors are renowned specialists in their fields and some of the new results presented here are documented for the first time in monographic form.

  4. Molecular and Cellular Signaling

    CERN Document Server

    Beckerman, Martin

    2005-01-01

    A small number of signaling pathways, no more than a dozen or so, form a control layer that is responsible for all signaling in and between cells of the human body. The signaling proteins belonging to the control layer determine what kinds of cells are made during development and how they function during adult life. Malfunctions in the proteins belonging to the control layer are responsible for a host of human diseases ranging from neurological disorders to cancers. Most drugs target components in the control layer, and difficulties in drug design are intimately related to the architecture of the control layer. Molecular and Cellular Signaling provides an introduction to molecular and cellular signaling in biological systems with an emphasis on the underlying physical principles. The text is aimed at upper-level undergraduates, graduate students and individuals in medicine and pharmacology interested in broadening their understanding of how cells regulate and coordinate their core activities and how diseases ...

  5. Activating the molecular spinterface

    Science.gov (United States)

    Cinchetti, Mirko; Dediu, V. Alek; Hueso, Luis E.

    2017-05-01

    The miniaturization trend in the semiconductor industry has led to the understanding that interfacial properties are crucial for device behaviour. Spintronics has not been alien to this trend, and phenomena such as preferential spin tunnelling, the spin-to-charge conversion due to the Rashba-Edelstein effect and the spin-momentum locking at the surface of topological insulators have arisen mainly from emergent interfacial properties, rather than the bulk of the constituent materials. In this Perspective we explore inorganic/molecular interfaces by looking closely at both sides of the interface. We describe recent developments and discuss the interface as an ideal platform for creating new spin effects. Finally, we outline possible technologies that can be generated thanks to the unique active tunability of molecular spinterfaces.

  6. Measuring Dark Molecular Gas

    Science.gov (United States)

    Li, Di; Heiles, Carl E.

    2017-01-01

    It is now well known that a substantial fraction of Galactic molecular gas cannot be traced by CO emission. The thus dubbed CO dark molecular gas (DMG) occupy a large volume of ISM with intermediate extinction, where CO is either not self-shielded and/or subthermally excited. We explore the utilities of simple hydrides, such OH, CH, etc., in tracing DMG. We mapped and modeled the transition zone cross a cloud boundary and derived emperical OH abundance and DMG distribution formulae. We also obtained absorption measurements of various species using Arecibo, VLA, ATCA, and ALMA. The absorption technique has the potential to provide systematic quantification of DMG in the next few years.

  7. 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 ...

  8. Molecular-beam scattering

    International Nuclear Information System (INIS)

    Vernon, M.F.

    1983-07-01

    The molecular-beam technique has been used in three different experimental arrangements to study a wide range of inter-atomic and molecular forces. Chapter 1 reports results of a low-energy (0.2 kcal/mole) elastic-scattering study of the He-Ar pair potential. The purpose of the study was to accurately characterize the shape of the potential in the well region, by scattering slow He atoms produced by expanding a mixture of He in N 2 from a cooled nozzle. Chapter 2 contains measurements of the vibrational predissociation spectra and product translational energy for clusters of water, benzene, and ammonia. The experiments show that most of the product energy remains in the internal molecular motions. Chapter 3 presents measurements of the reaction Na + HCl → NaCl + H at collision energies of 5.38 and 19.4 kcal/mole. This is the first study to resolve both scattering angle and velocity for the reaction of a short lived (16 nsec) electronic excited state. Descriptions are given of computer programs written to analyze molecular-beam expansions to extract information characterizing their velocity distributions, and to calculate accurate laboratory elastic-scattering differential cross sections accounting for the finite apparatus resolution. Experimental results which attempted to determine the efficiency of optically pumping the Li(2 2 P/sub 3/2/) and Na(3 2 P/sub 3/2/) excited states are given. A simple three-level model for predicting the steady-state fraction of atoms in the excited state is included

  9. Molecular Mechanisms of Preeclampsia

    OpenAIRE

    N. Vitoratos; D. Hassiakos; C. Iavazzo

    2012-01-01

    Preeclampsia is a pregnancy-specific disease characterized by new onset hypertension and proteinuria after 20 wk of gestation. It is a leading cause of maternal and fetal morbidity and mortality worldwide. Exciting discoveries in the last decade have contributed to a better understanding of the molecular basis of this disease. Epidemiological, experimental, and therapeutic studies from several laboratories have provided compelling evidence that an antiangiogenic state owing to alterations in ...

  10. Molecular diagnostics of periodontitis

    OpenAIRE

    Izabela Korona-Głowniak; Radosław Siwiec; Marcin Berger; Anna Malm; Jolanta Szymańska

    2017-01-01

    The microorganisms that form dental plaque are the main cause of periodontitis. Their identification and the understanding of the complex relationships and interactions that involve these microorganisms, environmental factors and the host’s health status enable improvement in diagnostics and targeted therapy in patients with periodontitis. To this end, molecular diagnostics techniques (both techniques based on the polymerase chain reaction and those involving nucleic acid analysis via hybridi...

  11. Molecular diagnostics in endodontics

    OpenAIRE

    Rechenberg, Dan-Krister; Zehnder, Matthias

    2014-01-01

    Recent systematic reviews have substantiated the fact that current testing methods to assess the inflammatory state of the pulp and the periapical tissues are of limited value. Consequently, it may be time to search for alternative routes in endodontic diagnostics. Molecular assessment methods could be the future. However, in the field of endodontics, the research in that direction is only about to evolve. Because pulpal and periradicular diseases are related to opportunistic infections, diag...

  12. Molecular Diagnostics of ?-Thalassemia

    OpenAIRE

    Atanasovska, B; Bozhinovski, G; Chakalova, L; Kocheva, S; Karanfilski, O; Plaseska-Karanfiska, D

    2012-01-01

    A high-quality hemoglobinopathy diagnosis is based on the results of a number of tests including assays for molecular identification of causative mutations. We describe the current diagnostic strategy for the identification of ?-thalassemias and hemoglobin (Hb) variants at the International Reference Laboratory for Haemoglobinopathies, Research Centre for Genetic Engineering and Biotechnology (RCGEB) ?Georgi D. Efremov,? Skopje, Republic of Macedonia. Our overall approach and most of the meth...

  13. Molecular biomethods handbook

    National Research Council Canada - National Science Library

    Walker, John M; Rapley, Ralph

    2008-01-01

    ... the reader to a selection of analytical and preparative techniques that we considered to be frequently used by research workers in the field of molecular biology. Clearly, within the constraints of a single volume we had to be selective in the techniques we described. Since the first edition was published, science has continued to move on apace. For example, the use of microarray technology is now commonplace, nanotechnology has entered the scientific literature, microfluidic technology has be...

  14. Molecular Vaccines for Malaria

    Science.gov (United States)

    2010-01-01

    Removing inhibitory plasm ids from the cock- with the radiation-attenuated sporozoite (RAS) vaccine36•37 (see tail restored the immunogenicity of the...relative increased in vitro growth inhibitory activity against homologous to the P. folciparum antigen expressing plasm ids alone, and none parasites...25nm and have a molecular weight of 14.8 kDa. (C) Transmission electron microscopy image of P4c-Mal nanoparticles at 242 OOOx. The sample was

  15. Designing the molecular future

    OpenAIRE

    Schneider Gisbert

    2011-01-01

    Approximately 25 years ago the first computer applications were conceived for the purpose of automated 'de novo' drug design prominent pioneering tools being ALADDIN CAVEAT GENOA and DYLOMMS. Many of these early concepts were enabled by innovative techniques for ligand receptor interaction modeling like GRID MCSS DOCK and CoMFA which still provide the theoretical framework for several more recently developed molecular design algorithms. After a first wave of software tools and groundbreaking ...

  16. Atomic and molecular theory

    International Nuclear Information System (INIS)

    Inokuti, Mitio.

    1990-01-01

    The multifaceted role of theoretical physics in understanding the earliest stages of radiation action is discussed. Scientific topics chosen for the present discourse include photoabsorption, electron collisions, and ionic collisions, and electron transport theory, Connections of atomic and molecular physics with condensed-matter physics are also discussed. The present article includes some historical perspective and an outlook for the future. 114 refs., 3 figs

  17. Molecular ecological network analyses.

    Science.gov (United States)

    Deng, Ye; Jiang, Yi-Huei; Yang, Yunfeng; He, Zhili; Luo, Feng; Zhou, Jizhong

    2012-05-30

    Understanding the interaction among different species within a community and their responses to environmental changes is a central goal in ecology. However, defining the network structure in a microbial community is very challenging due to their extremely high diversity and as-yet uncultivated status. Although recent advance of metagenomic technologies, such as high throughout sequencing and functional gene arrays, provide revolutionary tools for analyzing microbial community structure, it is still difficult to examine network interactions in a microbial community based on high-throughput metagenomics data. Here, we describe a novel mathematical and bioinformatics framework to construct ecological association networks named molecular ecological networks (MENs) through Random Matrix Theory (RMT)-based methods. Compared to other network construction methods, this approach is remarkable in that the network is automatically defined and robust to noise, thus providing excellent solutions to several common issues associated with high-throughput metagenomics data. We applied it to determine the network structure of microbial communities subjected to long-term experimental warming based on pyrosequencing data of 16 S rRNA genes. We showed that the constructed MENs under both warming and unwarming conditions exhibited topological features of scale free, small world and modularity, which were consistent with previously described molecular ecological networks. Eigengene analysis indicated that the eigengenes represented the module profiles relatively well. In consistency with many other studies, several major environmental traits including temperature and soil pH were found to be important in determining network interactions in the microbial communities examined. To facilitate its application by the scientific community, all these methods and statistical tools have been integrated into a comprehensive Molecular Ecological Network Analysis Pipeline (MENAP), which is open

  18. Molecular Gastronomy in Spain

    OpenAIRE

    García-Segovia, Purificación; Garrido, María Dolores; Vercet Tormo, Antonio; Arboleya, Juan Carlos; FISZMAN DAL SANTO, SUSANA; Martínez Monzó, Javier; Laguarda, Sergio; Palacios, Victor; Ruiz Carrascal, Jorge

    2014-01-01

    [EN] Beyond the overwhelming international success of Ferrán Adria, Spain has been one of the countries with a more active implication in molecular gastronomy as a scientific discipline but also in the use of ingredients, technologies, and equipment from the scientificand technological universe in the culinary area. Nowadays, this is a well-established discipline in Spain, with a number of research groups covering related topics, several companies commercializing appliances and additives worl...

  19. Communication: Molecular gears

    Energy Technology Data Exchange (ETDEWEB)

    Burnell, E. Elliott, E-mail: elliott.burnell@ubc.ca [Chemistry Department, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1 (Canada); Lange, Cornelis A. de, E-mail: c.a.de.lange@vu.nl [Atomic, Molecular and Laser Physics, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam (Netherlands); Meerts, W. Leo, E-mail: leo.meerts@science.ru.nl [Atomic, Molecular and Laser Physics, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam (Netherlands); Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, NL-6525 AJ Nijmegen (Netherlands)

    2016-09-07

    The {sup 1}H nuclear magnetic resonance spectrum of hexamethylbenzene orientationally ordered in the nematic liquid crystal ZLI-1132 is analysed using covariance matrix adaptation evolution strategy. The spectrum contains over 350 000 lines with many overlapping transitions, from which four independent direct dipolar couplings are obtained. The rotations of the six methyl groups appear to be correlated due to mutual steric hindrance. Adjacent methyl groups show counter-rotating or geared motion. Hexamethylbenzene thus behaves as a molecular hexagonal gear.

  20. Atomic and molecular theory

    Energy Technology Data Exchange (ETDEWEB)

    Inokuti, Mitio.

    1990-01-01

    The multifaceted role of theoretical physics in understanding the earliest stages of radiation action is discussed. Scientific topics chosen for the present discourse include photoabsorption, electron collisions, and ionic collisions, and electron transport theory, Connections of atomic and molecular physics with condensed-matter physics are also discussed. The present article includes some historical perspective and an outlook for the future. 114 refs., 3 figs.

  1. Molecular basis of alcoholism.

    Science.gov (United States)

    Most, Dana; Ferguson, Laura; Harris, R Adron

    2014-01-01

    Acute alcohol intoxication causes cellular changes in the brain that last for hours, while chronic alcohol use induces widespread neuroadaptations in the nervous system that can last a lifetime. Chronic alcohol use and the progression into dependence involve the remodeling of synapses caused by changes in gene expression produced by alcohol. The progression of alcohol use, abuse, and dependence can be divided into stages, which include intoxication, withdrawal, and craving. Each stage is associated with specific changes in gene expression, cellular function, brain circuits, and ultimately behavior. What are the molecular mechanisms underlying the transition from recreational use (acute) to dependence (chronic)? What cellular adaptations result in drug memory retention, leading to the persistence of addictive behaviors, even after prolonged drug abstinence? Research into the neurobiology of alcoholism aims to answer these questions. This chapter will describe the molecular adaptations caused by alcohol use and dependence, and will outline key neurochemical participants in alcoholism at the molecular level, which are also potential targets for therapy. © 2014 Elsevier B.V. All rights reserved.

  2. Molecular symmetry and spectroscopy

    CERN Document Server

    Bunker, Philip; Jensen, Per

    2006-01-01

    The first edition, by P.R. Bunker, published in 1979, remains the sole textbook that explains the use of the molecular symmetry group in understanding high resolution molecular spectra. Since 1979 there has been considerable progress in the field and a second edition is required; the original author has been joined in its writing by Per Jensen. The Material of the first edition has been reorganized and much has been added. The molecular symmetry group is now introduced early on, and the explanation of how to determine nuclear spin statistical weights has been consolidated in one chapter, after groups, symmetry groups, character tables and the Hamiltonian have been introduced. A description of the symmetry in the three-dimensional rotation group K(spatial), irreducible spherical tensor operators, and vector coupling coefficients is now included. The chapters on energy levels and selection rules contain a great deal of material that was not in the first edition (much of it was undiscovered in 1979), concerning ...

  3. Molecular markers in glioma.

    Science.gov (United States)

    Ludwig, Kirsten; Kornblum, Harley I

    2017-09-01

    Gliomas are the most malignant and aggressive form of brain tumors, and account for the majority of brain cancer related deaths. Malignant gliomas, including glioblastoma are treated with radiation and temozolomide, with only a minor benefit in survival time. A number of advances have been made in understanding glioma biology, including the discovery of cancer stem cells, termed glioma stem cells (GSC). Some of these advances include the delineation of molecular heterogeneity both between tumors from different patients as well as within tumors from the same patient. Such research highlights the importance of identifying and validating molecular markers in glioma. This review, intended as a practical resource for both clinical and basic investigators, summarizes some of the more well-known molecular markers (MGMT, 1p/19q, IDH, EGFR, p53, PI3K, Rb, and RAF), discusses how they are identified, and what, if any, clinical relevance they may have, in addition to discussing some of the specific biology for these markers. Additionally, we discuss identification methods for studying putative GSC's (CD133, CD15, A2B5, nestin, ALDH1, proteasome activity, ABC transporters, and label-retention). While much research has been done on these markers, there is still a significant amount that we do not yet understand, which may account for some conflicting reports in the literature. Furthermore, it is unlikely that the investigator will be able to utilize one single marker to prospectively identify and isolate GSC from all, or possibly, any gliomas.

  4. Cooling of molecular ion beams

    International Nuclear Information System (INIS)

    Wolf, A.; Krohn, S.; Kreckel, H.; Lammich, L.; Lange, M.; Strasser, D.; Grieser, M.; Schwalm, D.; Zajfman, D.

    2004-01-01

    An overview of the use of stored ion beams and phase space cooling (electron cooling) is given for the field of molecular physics. Emphasis is given to interactions between molecular ions and electrons studied in the electron cooler: dissociative recombination and, for internally excited molecular ions, electron-induced ro-vibrational cooling. Diagnostic methods for the transverse ion beam properties and for the internal excitation of the molecular ions are discussed, and results for phase space cooling and internal (vibrational) cooling are presented for hydrogen molecular ions

  5. THE CALIFORNIA MOLECULAR CLOUD

    International Nuclear Information System (INIS)

    Lada, Charles J.; Lombardi, Marco; Alves, Joao F.

    2009-01-01

    We present an analysis of wide-field infrared extinction maps of a region in Perseus just north of the Taurus-Auriga dark cloud complex. From this analysis we have identified a massive, nearby, but previously unrecognized, giant molecular cloud (GMC). Both a uniform foreground star density and measurements of the cloud's velocity field from CO observations indicate that this cloud is likely a coherent structure at a single distance. From comparison of foreground star counts with Galactic models, we derive a distance of 450 ± 23 pc to the cloud. At this distance the cloud extends over roughly 80 pc and has a mass of ∼ 10 5 M sun , rivaling the Orion (A) molecular cloud as the largest and most massive GMC in the solar neighborhood. Although surprisingly similar in mass and size to the more famous Orion molecular cloud (OMC) the newly recognized cloud displays significantly less star formation activity with more than an order of magnitude fewer young stellar objects than found in the OMC, suggesting that both the level of star formation and perhaps the star formation rate in this cloud are an order of magnitude or more lower than in the OMC. Analysis of extinction maps of both clouds shows that the new cloud contains only 10% the amount of high extinction (A K > 1.0 mag) material as is found in the OMC. This, in turn, suggests that the level of star formation activity and perhaps the star formation rate in these two clouds may be directly proportional to the total amount of high extinction material and presumably high density gas within them and that there might be a density threshold for star formation on the order of n(H 2 ) ∼ a few x 10 4 cm -3 .

  6. Computational methods for molecular imaging

    CERN Document Server

    Shi, Kuangyu; Li, Shuo

    2015-01-01

    This volume contains original submissions on the development and application of molecular imaging computing. The editors invited authors to submit high-quality contributions on a wide range of topics including, but not limited to: • Image Synthesis & Reconstruction of Emission Tomography (PET, SPECT) and other Molecular Imaging Modalities • Molecular Imaging Enhancement • Data Analysis of Clinical & Pre-clinical Molecular Imaging • Multi-Modal Image Processing (PET/CT, PET/MR, SPECT/CT, etc.) • Machine Learning and Data Mining in Molecular Imaging. Molecular imaging is an evolving clinical and research discipline enabling the visualization, characterization and quantification of biological processes taking place at the cellular and subcellular levels within intact living subjects. Computational methods play an important role in the development of molecular imaging, from image synthesis to data analysis and from clinical diagnosis to therapy individualization. This work will bring readers fro...

  7. Molecular Mechanisms of Preeclampsia.

    Science.gov (United States)

    Hod, Tammy; Cerdeira, Ana Sofia; Karumanchi, S Ananth

    2015-08-20

    Preeclampsia is a pregnancy-specific disease characterized by new onset hypertension and proteinuria after 20 wk of gestation. It is a leading cause of maternal and fetal morbidity and mortality worldwide. Exciting discoveries in the last decade have contributed to a better understanding of the molecular basis of this disease. Epidemiological, experimental, and therapeutic studies from several laboratories have provided compelling evidence that an antiangiogenic state owing to alterations in circulating angiogenic factors leads to preeclampsia. In this review, we highlight the role of key circulating antiangiogenic factors as pathogenic biomarkers and in the development of novel therapies for preeclampsia. Copyright © 2015 Cold Spring Harbor Laboratory Press; all rights reserved.

  8. De novo molecular design

    CERN Document Server

    Schneider, Gisbert

    2013-01-01

    Systematically examining current methods and strategies, this ready reference covers a wide range of molecular structures, from organic-chemical drugs to peptides, Proteins and nucleic acids, in line with emerging new drug classes derived from biomacromolecules. A leader in the field and one of the pioneers of this young discipline has assembled here the most prominent experts from across the world to provide first-hand knowledge. While most of their methods and examples come from the area of pharmaceutical discovery and development, the approaches are equally applicable for chemical probes an

  9. Molecular water oxidation catalysis

    CERN Document Server

    Llobet, Antoni

    2014-01-01

    Photocatalytic water splitting is a promising strategy for capturing energy from the sun by coupling light harvesting and the oxidation of water, in order to create clean hydrogen fuel. Thus a deep knowledge of the water oxidation catalysis field is essential to be able to come up with useful energy conversion devices based on sunlight and water splitting. Molecular Water Oxidation Catalysis: A Key Topic for New Sustainable Energy Conversion Schemes presents a comprehensive and state-of-the-art overview of water oxidation catalysis in homogeneous phase, describing in detail the most importan

  10. Nuclear molecular states

    International Nuclear Information System (INIS)

    Abe, Y.

    1975-01-01

    The effects of polarization on the stability of α-cluster structures in 8 Be and 12 C nuclei are studied in the intrinsic states. The extent of the polarization of α-clusters is investigated by employing a molecular-orbital model. Two α-cluster structure of 8 Be is shown to be extremely stable, and a triangular configuration of three α-clusters is also shown to be stable, but the polarizations of α-clusters are found rather large. Gruemmer--Faessler's method is discussed and their results are shown to be trivial

  11. Molecular epidemiology of ascariasis

    DEFF Research Database (Denmark)

    Betson, Martha; Halstead, Fennella; Nejsum, Peter

      We are using molecular epidemiology techniques to study the population structure of Ascaris obtained from humans and pigs. Worms were obtained from human hosts on Zanzibar and in Uganda, Bangladesh, Guatemala and Nepal and Ascaris from pigs were collected from in Uganda, Tanzania, Denmark......, Guatemala and the Philippines. Genomic DNA was extracted from each worm and a 450 base pair fragment of the mitochondrial cytochrome oxidase gene subunit 1 (COI) was PCR amplified. The products were sequenced from both strands and sequences were manually edited. Fifty different Ascaris CO1 haplotypes were...

  12. Molecular collision theory

    CERN Document Server

    Child, M S

    2010-01-01

    This high-level monograph offers an excellent introduction to the theory required for interpretation of an increasingly sophisticated range of molecular scattering experiments. There are five helpful appendixes dealing with continuum wavefunctions, Green's functions, semi-classical connection formulae, curve-crossing in the momentum representation, and elements of classical mechanics.The contents of this volume have been chosen to emphasize the quantum mechanical and semi-classical nature of collision events, with little attention given to purely classical behavior. The treatment is essentiall

  13. The nonequilibrium molecular dynamics

    International Nuclear Information System (INIS)

    Hoover, W.G.

    1992-03-01

    MOLECULAR DYNAMICS has been generalized in order to simulate a variety of NONEQUILIBRIUM systems. This generalization has been achieved by adopting microscopic mechanical definitions of macroscopic thermodynamic and hydrodynamic variables, such as temperature and stress. Some of the problems already treated include rapid plastic deformation, intense heat conduction, strong shockwaves simulation, and far-from-equilibrium phase transformations. Continuing advances in technique and in the modeling of interatomic forces, coupled with qualitative improvements in computer hardware, are enabling such simulations to approximate real-world microscale and nanoscale experiments

  14. Molecular Mechanisms of Preeclampsia

    Science.gov (United States)

    Hod, Tammy; Cerdeira, Ana Sofia; Karumanchi, S. Ananth

    2015-01-01

    Preeclampsia is a pregnancy-specific disease characterized by new onset hypertension and proteinuria after 20 wk of gestation. It is a leading cause of maternal and fetal morbidity and mortality worldwide. Exciting discoveries in the last decade have contributed to a better understanding of the molecular basis of this disease. Epidemiological, experimental, and therapeutic studies from several laboratories have provided compelling evidence that an antiangiogenic state owing to alterations in circulating angiogenic factors leads to preeclampsia. In this review, we highlight the role of key circulating antiangiogenic factors as pathogenic biomarkers and in the development of novel therapies for preeclampsia. PMID:26292986

  15. Introduction to basic molecular biologic techniques for molecular imaging researches

    International Nuclear Information System (INIS)

    Kang, Joo Hyun

    2004-01-01

    Molecular imaging is a rapidly growing field due to the advances in molecular biology and imaging technologies. With the introduction of imaging reporter genes into the cell, diverse cellular processes can be monitored, quantified and imaged non-invasively in vivo. These processes include the gene expression, protein-protein interactions, signal transduction pathways, and monitoring of cells such as cancer cells, immune cells, and stem cells. In the near future, molecular imaging analysis will allow us to observe the incipience and progression of the disease. These will make us easier to give a diagnosis in the early stage of intractable diseases such as cancer, neuro-degenerative disease, and immunological disorders. Additionally, molecular imaging method will be a valuable tool for the real-time evaluation of cells in molecular biology and the basic biological studies. As newer and more powerful molecular imaging tools become available, it will be necessary to corporate clinicians, molecular biologists and biochemists for the planning, interpretation, and application of these techniques to their fullest potential. In order for such a multidisciplinary team to be effective, it is essential that a common understanding of basic biochemical and molecular biologic techniques is achieved. Basic molecular techniques for molecular imaging methods are presented in this paper

  16. Photoinduced diffusion molecular transport

    Energy Technology Data Exchange (ETDEWEB)

    Rozenbaum, Viktor M., E-mail: vik-roz@mail.ru, E-mail: litrakh@gmail.com [Chuiko Institute of Surface Chemistry, National Academy of Sciences of Ukraine, Generala Naumova St. 17, Kiev 03164 (Ukraine); Dekhtyar, Marina L. [Institute of Organic Chemistry, National Academy of Sciences of Ukraine, Murmanskaya St. 5, Kiev 02094 (Ukraine); Lin, Sheng Hsien [Department of Applied Chemistry, National Chiao Tung University, 1001 Ta Hsuen Road, Hsinchu 300, Taiwan (China); Trakhtenberg, Leonid I., E-mail: vik-roz@mail.ru, E-mail: litrakh@gmail.com [Semenov Institute of Chemical Physics, Russian Academy of Sciences, Kosygin Street 4, Moscow 119991, Russia and Moscow Institute of Physics and Technology (State University), Institutskii Per. 9, Dolgoprudnyi, Moscow Region 141700 (Russian Federation)

    2016-08-14

    We consider a Brownian photomotor, namely, the directed motion of a nanoparticle in an asymmetric periodic potential under the action of periodic rectangular resonant laser pulses which cause charge redistribution in the particle. Based on the kinetics for the photoinduced electron redistribution between two or three energy levels of the particle, the time dependence of its potential energy is derived and the average directed velocity is calculated in the high-temperature approximation (when the spatial amplitude of potential energy fluctuations is small relative to the thermal energy). The thus developed theory of photoinduced molecular transport appears applicable not only to conventional dichotomous Brownian motors (with only two possible potential profiles) but also to a much wider variety of molecular nanomachines. The distinction between the realistic time dependence of the potential energy and that for a dichotomous process (a step function) is represented in terms of relaxation times (they can differ on the time intervals of the dichotomous process). As shown, a Brownian photomotor has the maximum average directed velocity at (i) large laser pulse intensities (resulting in short relaxation times on laser-on intervals) and (ii) excited state lifetimes long enough to permit efficient photoexcitation but still much shorter than laser-off intervals. A Brownian photomotor with optimized parameters is exemplified by a cylindrically shaped semiconductor nanocluster which moves directly along a polar substrate due to periodically photoinduced dipole moment (caused by the repetitive excited electron transitions to a non-resonant level of the nanocylinder surface impurity).

  17. Chemoradiotherapy and molecular biology

    International Nuclear Information System (INIS)

    Hasegawa, Masatoshi; Mitsuhashi, Norio; Niibe, Hideo

    2000-01-01

    The current status of chemoradiotherapy was reviewed from the standpoint of molecular biology. Chemoradiotherapy was conducted to achieve systemic tumor control, to intensify the response to irradiation, and to reduce adverse reactions. The mechanisms of the efficacy of chemoradiotherapy were: modification of dose-response relationships, inhibition of tumor cell recovery from sublethal damage or potential lethal damage, effects on cell dynamics and the cell cycle, improvement of blood flow or reoxygenation, recruitment, improvement of drug uptake, increased cell damage. Cell death (necrosis and apoptosis) and cancer-related genes were described, as the essential points, because they are involved in the response to chemoradiotherapy. Cisplatin (platinum compound), 5-fluorouracil, etoposide, and taxoid (paclitaxel, docetaxel) were the principal anticancer agents used for chemoradiotherapy, and they enhanced the effects of irradiation. However, even when good responses or synergism between anticancer drug and radiotherapy was observed in in vitro studies, there was little therapeutic advantage clinically. Data from in vitro and in vivo studies should be collected and systemized, and ''molecular biology in chemotherapy'' that can be applied clinically may become established. (K.H.)

  18. Molecular beam kinetics

    International Nuclear Information System (INIS)

    Behrens, R. Jr.

    1975-11-01

    The design of a crossed molecular beam ''supermachine'' for neutral--neutral collisions is discussed. The universal electron bombardment ionizer, mass filter, and ion detection system of the detector, the supersonic nozzle sources, the differential pumping arrangement for the sources and detector, the time-of-flight detection of scattered products, and the overall configuration of the apparatus are described. The elastic scattering of two systems, CH 4 + Ar and NH 3 + Ar, has been measured using the supermachine with two supersonic nozzle sources. The rainbow structure and the interference oscillations are seen in each system. The best fit to the data was found using a Morse--Spline--Van der Waals (MSV) potential. The three potential parameters epsilon, r/sub m/, and β were found to be 2.20(+-0.04) x 10 -14 ergs, 3.82(+-0.04)A, and 7.05 +- 0.20 for CH 4 + Ar, and 2.21(+-0.04) x 10 -14 ergs 3.93 (+-0.05)A, and 8.45 +- 0.30 for NH 3 + Ar. A new phenomenon in crossed molecular beams of condensation of a molecule on a cluster to form a complex was observed. A bromine molecule condensed on clusters of chlorine (Cl 2 )/sub chi/ and ammonia (NH 3 )/sub chi/. The value of chi for measurements in these experiments ranges from 7 to 40 for chlorine clusters and from 10 to 70 ammonia clusters

  19. Molecular biology of potyviruses.

    Science.gov (United States)

    Revers, Frédéric; García, Juan Antonio

    2015-01-01

    Potyvirus is the largest genus of plant viruses causing significant losses in a wide range of crops. Potyviruses are aphid transmitted in a nonpersistent manner and some of them are also seed transmitted. As important pathogens, potyviruses are much more studied than other plant viruses belonging to other genera and their study covers many aspects of plant virology, such as functional characterization of viral proteins, molecular interaction with hosts and vectors, structure, taxonomy, evolution, epidemiology, and diagnosis. Biotechnological applications of potyviruses are also being explored. During this last decade, substantial advances have been made in the understanding of the molecular biology of these viruses and the functions of their various proteins. After a general presentation on the family Potyviridae and the potyviral proteins, we present an update of the knowledge on potyvirus multiplication, movement, and transmission and on potyvirus/plant compatible interactions including pathogenicity and symptom determinants. We end the review providing information on biotechnological applications of potyviruses. © 2015 Elsevier Inc. All rights reserved.

  20. Light and redox switchable molecular components for molecular electronics.

    Science.gov (United States)

    Browne, Wesley R; Feringa, Ben L

    2010-01-01

    The field of molecular and organic electronics has seen rapid progress in recent years, developing from concept and design to actual demonstration devices in which both single molecules and self-assembled monolayers are employed as light-responsive components. Research in this field has seen numerous unexpected challenges that have slowed progress and the initial promise of complex molecular-based computers has not yet been realised. Primarily this has been due to the realisation at an early stage that molecular-based nano-electronics brings with it the interface between the hard (semiconductor) and soft (molecular) worlds and the challenges which accompany working in such an environment. Issues such as addressability, cross-talk, molecular stability and perturbation of molecular properties (e.g., inhibition of photochemistry) have nevertheless driven development in molecular design and synthesis as well as our ability to interface molecular components with bulk metal contacts to a very high level of sophistication. Numerous groups have played key roles in progressing this field not least teams such as those led by Whitesides, Aviram, Ratner, Stoddart and Heath. In this short review we will however focus on the contributions from our own group and those of our collaborators, in employing diarylethene based molecular components.

  1. Assessment of Molecular Modeling & Simulation

    Energy Technology Data Exchange (ETDEWEB)

    None

    2002-01-03

    This report reviews the development and applications of molecular and materials modeling in Europe and Japan in comparison to those in the United States. Topics covered include computational quantum chemistry, molecular simulations by molecular dynamics and Monte Carlo methods, mesoscale modeling of material domains, molecular-structure/macroscale property correlations like QSARs and QSPRs, and related information technologies like informatics and special-purpose molecular-modeling computers. The panel's findings include the following: The United States leads this field in many scientific areas. However, Canada has particular strengths in DFT methods and homogeneous catalysis; Europe in heterogeneous catalysis, mesoscale, and materials modeling; and Japan in materials modeling and special-purpose computing. Major government-industry initiatives are underway in Europe and Japan, notably in multi-scale materials modeling and in development of chemistry-capable ab-initio molecular dynamics codes.

  2. Gas Phase Molecular Dynamics

    International Nuclear Information System (INIS)

    Hall, G.E.; Prrese, J.M.; Sears, T.J.; Weston, R.E.

    1999-01-01

    The goal of this research is the understanding of elementary chemical and physical processes important in the combustion of fossil fuels. Interest centers on reactions involving short-lived chemical intermediates and their properties. High-resolution high-sensitivity laser absorption methods are augmented by high temperature flow-tube reaction kinetics studies with mass spectrometric sampling. These experiments provide information on the energy levels, structures and reactivity of molecular flee radical species and, in turn, provide new tools for the study of energy flow and chemical bond cleavage in the radicals in chemical systems. The experimental work is supported by theoretical and computational work using time-dependent quantum wave packet calculations that provide insights into energy flow between the vibrational modes of the molecule

  3. Molecular genetics in neurology.

    Science.gov (United States)

    Martin, J B

    1993-12-01

    There has been remarkable progress in the identification of mutations in genes that cause inherited neurological disorders. Abnormalities in the genes for Huntington disease, neurofibromatosis types 1 and 2, one form of familial amyotrophic lateral sclerosis, fragile X syndrome, myotonic dystrophy, Kennedy syndrome, Menkes disease, and several forms of retinitis pigmentosa have been elucidated. Rare disorders of neuronal migration such as Kallmann syndrome, Miller-Dieker syndrome, and Norrie disease have been shown to be due to specific gene defects. Several muscle disorders characterized by abnormal membrane excitability have been defined as mutations of the muscle sodium or chloride channels. These advances provide opportunity for accurate molecular diagnosis of at-risk individuals and are the harbinger of new approaches to therapy of these diseases.

  4. Molecular mechanisms in gliomagenesis

    DEFF Research Database (Denmark)

    Hulleman, Esther; Helin, Kristian

    2005-01-01

    Glioma, and in particular high-grade astrocytoma termed glioblastoma multiforme (GBM), is the most common primary tumor of the brain. Primarily because of its diffuse nature, there is no effective treatment for GBM, and relatively little is known about the processes by which it develops. Therefore......, in order to design novel therapies and treatments for GBM, research has recently intensified to identify the cellular and molecular mechanisms leading to GBM formation. Modeling of astrocytomas by genetic manipulation of mice suggests that deregulation of the pathways that control gliogenesis during normal...... brain development, such as the differentiation of neural stem cells (NSCs) into astrocytes, might contribute to GBM formation. These pathways include growth factor-induced signal transduction routes and processes that control cell cycle progression, such as the p16-CDK4-RB and the ARF-MDM2-p53 pathways...

  5. Atomic and molecular sciences

    International Nuclear Information System (INIS)

    Lane, N.F.

    1989-01-01

    The theoretical atomic and molecular physics program at Rice University addresses basic questions about the collision dynamics of electrons, atoms, ions and molecules, emphasizing processes related to possible new energy technologies and other applications. The program focuses on inelastic collision processes that are important in understanding energy and ionization balance in disturbed gases and plasmas. Emphasis is placed on systems and processes where some experimental information is available or where theoretical results may be expected to stimulate new measurements. Examples of current projects include: excitation and charge-transfer processes; orientation and alignment of excited states following collisions; Rydberg atom collisions with atoms and molecules; Penning ionization and ion-pair formation in atom-atom collisions; electron-impact ionization in dense, high-temperature plasmas; electron-molecule collisions; and related topics

  6. Atomic and molecular manipulation

    CERN Document Server

    Mayne, Andrew J

    2011-01-01

    Work with individual atoms and molecules aims to demonstrate that miniaturized electronic, optical, magnetic, and mechanical devices can operate ultimately even at the level of a single atom or molecule. As such, atomic and molecular manipulation has played an emblematic role in the development of the field of nanoscience. New methods based on the use of the scanning tunnelling microscope (STM) have been developed to characterize and manipulate all the degrees of freedom of individual atoms and molecules with an unprecedented precision. In the meantime, new concepts have emerged to design molecules and substrates having specific optical, mechanical and electronic functions, thus opening the way to the fabrication of real nano-machines. Manipulation of individual atoms and molecules has also opened up completely new areas of research and knowledge, raising fundamental questions of "Optics at the atomic scale", "Mechanics at the atomic scale", Electronics at the atomic scale", "Quantum physics at the atomic sca...

  7. Molecular Interactions at Membranes

    DEFF Research Database (Denmark)

    Jagalski, Vivien

    . Today, we know more than ever before about the properties of biological membranes. Advanced biophysical techniques and sophisticated membrane models allow us to answer specific questions about the structure of the components within membranes and their interactions. However, many detailed structural...... the surface-immobilization of LeuT by exchanging the detergent with natural phosphatidylcholine (PC) lipids. Various surface sensitive techniques, including neutron reflectometry (NR), are employed and finally enabled us to confirm the gross structure of LeuT in a lipid environment as predicted by molecular...... dynamic simulations. In a second study, the co-localization of three toxic plant-derived diterpene resin acids (RAs) within DPPC membranes was investigated. These compounds are reported to disrupt the membrane and increase its fluidity. The RAs used in this study vary in their toxicity while...

  8. Molecular mechanisms of carcinogenesis

    International Nuclear Information System (INIS)

    Hall, E.J.

    1997-01-01

    The possibility that chromosomal changes are responsible for neoplasia was proposed in the early years of this century. A combination of improved cytogenetics and the advent of recombinant technology has settled the issue. As recently as 20 years ago, however, the genetic and molecular basis of familiar predisposition to cancer were a mystery, and it is only in the last few years that light has been shed on a few specific types of malignancies. As the genetic basis of human cancer had been documented, a number of genes have been identified as functioning either as oncogenes which act in a dominant fashion to promote tumor growth when mutated, or as tumor suppressor genes which act in a recessive fashion

  9. Molecular genetics of craniosynostosis

    Science.gov (United States)

    Caterine; Auerkari, Elza Ibrahim

    2018-03-01

    Tight regulation process and complex interplay occur along the osteogenic interfaces of the cranial sutures in normal growth and development of the skull. Cranial sutures serve as sites of bone growth while maintaining a state of patency to accommodate the developing brain. Cranial sutures are fibro-cellular structures that separate the rigid plates of the skull bones. Premature fusion of one or more cranial sutures leads to a condition known as craniosynostosis. Craniosynostosis is one of the most common craniofacial anomalies with a prevalence of 1 in 2,500 newborns. Several genes have been identified in the pathogenesis of craniosynostosis. Molecular signaling events and the intracellular signal transduction pathways implicated in the suture pathobiology will provide a useful approach for therapeutic targeting.

  10. Molecular imaging II

    International Nuclear Information System (INIS)

    Semmler, Wolfhard; Schwaiger, Markus

    2008-01-01

    The aim of this textbook of molecular imaging is to provide an up to date review of this rapidly growing field and to discuss basic methodological aspects necessary for the interpretation of experimental and clinical results. Emphasis is placed on the interplay of imaging technology and probe development, since the physical properties of the imaging approach need to be closely linked with the biologic application of the probe (i.e. nanoparticles and microbubbles). Various chemical strategies are discussed and related to the biologic applications. Reporter-gene imaging is being addressed not only in experimental protocols, but also first clinical applications are discussed. Finally, strategies of imaging to characterize apoptosis and angiogenesis are described and discussed in the context of possible clinical translation. (orig.)

  11. Molecular dynamics simulations

    International Nuclear Information System (INIS)

    Alder, B.J.

    1985-07-01

    The molecular dynamics computer simulation discovery of the slow decay of the velocity autocorrelation function in fluids is briefly reviewed in order to contrast that long time tail with those observed for the stress autocorrelation function in fluids and the velocity autocorrelation function in the Lorentz gas. For a non-localized particle in the Lorentz gas it is made plausible that even if it behaved quantum mechanically its long time tail would be the same as the classical one. The generalization of Fick's law for diffusion for the Lorentz gas, necessary to avoid divergences due to the slow decay of correlations, is presented. For fluids, that generalization has not yet been established, but the region of validity of generalized hydrodynamics is discussed. 20 refs., 5 figs

  12. Electrical properties of molecular crystals

    International Nuclear Information System (INIS)

    Barraud, A.

    1968-01-01

    This literature survey summarizes the electrical properties of molecular crystals: molecular crystal structure, transport and excitation mechanisms of charge-carriers, and differences compared to inorganic semi-conductors. The main results concerning the electrical conductivity of the most-studied molecular crystals are presented, together with the optical and photo-electrical properties of these crystals. Finally the different types of electrical measurements used are reviewed, as well as the limits of each method. (author) [fr

  13. Molecular machines open cell membranes.

    Science.gov (United States)

    García-López, Víctor; Chen, Fang; Nilewski, Lizanne G; Duret, Guillaume; Aliyan, Amir; Kolomeisky, Anatoly B; Robinson, Jacob T; Wang, Gufeng; Pal, Robert; Tour, James M

    2017-08-30

    Beyond the more common chemical delivery strategies, several physical techniques are used to open the lipid bilayers of cellular membranes. These include using electric and magnetic fields, temperature, ultrasound or light to introduce compounds into cells, to release molecular species from cells or to selectively induce programmed cell death (apoptosis) or uncontrolled cell death (necrosis). More recently, molecular motors and switches that can change their conformation in a controlled manner in response to external stimuli have been used to produce mechanical actions on tissue for biomedical applications. Here we show that molecular machines can drill through cellular bilayers using their molecular-scale actuation, specifically nanomechanical action. Upon physical adsorption of the molecular motors onto lipid bilayers and subsequent activation of the motors using ultraviolet light, holes are drilled in the cell membranes. We designed molecular motors and complementary experimental protocols that use nanomechanical action to induce the diffusion of chemical species out of synthetic vesicles, to enhance the diffusion of traceable molecular machines into and within live cells, to induce necrosis and to introduce chemical species into live cells. We also show that, by using molecular machines that bear short peptide addends, nanomechanical action can selectively target specific cell-surface recognition sites. Beyond the in vitro applications demonstrated here, we expect that molecular machines could also be used in vivo, especially as their design progresses to allow two-photon, near-infrared and radio-frequency activation.

  14. Molecular studies by electron spectroscopy

    International Nuclear Information System (INIS)

    Hansteen, J.M.

    1977-01-01

    Experience gained in experimental nuclear physics has played a large role in the development of electron spectroscopy as a powerful tool for studying chemical systems. The use of ESCA (Electron Spectroscopy for Chemical Analysis) for the mapping of molecular properties connected with inner as well as outer electron shells is reviewed, mainly from a phenomological point of view. Molecular Auger electron spectroscopy is described as a means of gaining information on details in molecular structure, simultaneously being extensively applied for surface studies. Future highly promising research areas for molecular electron spectroscopy are suggested to be (e,2e) processes as well as continued exploitation of synchrotron radiation from high energy nuclear devices. (Auth.)

  15. Molecular machines open cell membranes

    Science.gov (United States)

    García-López, Víctor; Chen, Fang; Nilewski, Lizanne G.; Duret, Guillaume; Aliyan, Amir; Kolomeisky, Anatoly B.; Robinson, Jacob T.; Wang, Gufeng; Pal, Robert; Tour, James M.

    2017-08-01

    Beyond the more common chemical delivery strategies, several physical techniques are used to open the lipid bilayers of cellular membranes. These include using electric and magnetic fields, temperature, ultrasound or light to introduce compounds into cells, to release molecular species from cells or to selectively induce programmed cell death (apoptosis) or uncontrolled cell death (necrosis). More recently, molecular motors and switches that can change their conformation in a controlled manner in response to external stimuli have been used to produce mechanical actions on tissue for biomedical applications. Here we show that molecular machines can drill through cellular bilayers using their molecular-scale actuation, specifically nanomechanical action. Upon physical adsorption of the molecular motors onto lipid bilayers and subsequent activation of the motors using ultraviolet light, holes are drilled in the cell membranes. We designed molecular motors and complementary experimental protocols that use nanomechanical action to induce the diffusion of chemical species out of synthetic vesicles, to enhance the diffusion of traceable molecular machines into and within live cells, to induce necrosis and to introduce chemical species into live cells. We also show that, by using molecular machines that bear short peptide addends, nanomechanical action can selectively target specific cell-surface recognition sites. Beyond the in vitro applications demonstrated here, we expect that molecular machines could also be used in vivo, especially as their design progresses to allow two-photon, near-infrared and radio-frequency activation.

  16. Molecular pathology and thyroid FNA.

    Science.gov (United States)

    Poller, D N; Glaysher, S

    2017-12-01

    This review summarises molecular pathological techniques applicable to thyroid FNA. The molecular pathology of thyroid tumours is now fairly well understood. Molecular methods may be used as a rule-in test for diagnosis of malignancy in thyroid nodules, eg BRAF V600E point mutation, use of a seven-gene mutational panel (BRAF V600E, RAS genes, RET/PTC or PAX8/PPARG rearrangement), or as a comprehensive multigene next-generation sequencing panel, eg ThyroSeq v2. Molecular methods can also be applied as rule-out tests for malignancy in thyroid nodules, eg Afirma or ThyroSeq v2 or as markers of prognosis, eg TERT promoter mutation or other gene mutations including BRAF V600E, TP53 and AKT1, and as tests for newly defined tumour entities such as non-invasive follicular thyroid neoplasm with papillary like nuclei, or as a molecular marker(s) for targeted therapies. This review describes practical examples of molecular techniques as applied to thyroid FNA in routine clinical practice and the value of molecular diagnostics in thyroid FNA. It describes the range of molecular abnormalities identified in thyroid nodules and thyroid cancers with some practical applications of molecular methods to diagnosis and prognosis of thyroid nodules and thyroid cancer. © 2017 John Wiley & Sons Ltd.

  17. Thermally driven molecular linear motors - A molecular dynamics study

    DEFF Research Database (Denmark)

    Zambrano, Harvey A; Walther, Jens Honore; Jaffe, Richard Lawrence

    2009-01-01

    We conduct molecular dynamics simulations of a molecular linear motor consisting of coaxial carbon nanotubes with a long outer carbon nanotube confining and guiding the motion of an inner short, capsule-like nanotube. The simulations indicate that the motion of the capsule can be controlled by th...

  18. Bienvenida la Medicina Molecular

    Directory of Open Access Journals (Sweden)

    Orlando R. Serrano-Barrera

    2015-11-01

    Full Text Available No ha cambiado la medicina, sino que ha avanzado. Los métodos clínico-epidemiológicos  incluyen hoy y se benefician del conocimiento de las bases moleculares del proceso salud-enfermedad, tanto las variaciones individuales, como los caracteres compartidos por comunidades y poblaciones, que las hacen resistentes o vulnerables a una enfermedad. La estimación presintomática e, incluso, prenatal del riesgo de enfermar, el diagnóstico, el pronóstico, la elección del tratamiento más ajustado al paciente, las posibilidades de rehabilitación y reinserción social, la educación y promoción sanitarias son todos momentos del proceso de toma de decisiones, que el médico debe asumir en el nuevo escenario de una ciencia que ha logrado discernir las implicaciones de un número creciente de moléculas, sus variantes, sus formas mutadas y sus interacciones con otras moléculas y con factores ambientales. (1 ¿Cuán lejos está tal panorama de nuestra práctica clínica? También en nuestros escenarios se hace medicina molecular. Así ha sido desde que en 1949 Pauling catalogara la primera enfermedad molecular: la anemia drepanocítica. (2 La más temprana acción de prevención, la vacunación, se realiza a diario en las áreas de salud e incluye preparados conformados por moléculas obtenidas por vía recombinante o síntesis química, como el antígeno de superficie del virus de la hepatitis B y el polisacárido de membrana del Haemophilus influenzae, respectivamente. (3 La pesquisa poblacional de cáncer de próstata, enfocado hacia los hombres mayores de 50 años o con síntomas sugestivos, se auxilia de la cuantificación en sangre del antígeno prostático específico. (4 El tratamiento del infarto agudo del miocardio, ahora la segunda causa de muerte en Cuba, incluye la trombolisis con estreptocinasa, otra biomolécula recombinante. (5 En desarrollo, en etapa de ensayos clínicos o ya como productos registrados algunas vacunas terap

  19. Molecular digital pathology: progress and potential of exchanging molecular data.

    Science.gov (United States)

    Roy, Somak; Pfeifer, John D; LaFramboise, William A; Pantanowitz, Liron

    2016-09-01

    Many of the demands to perform next generation sequencing (NGS) in the clinical laboratory can be resolved using the principles of telepathology. Molecular telepathology can allow facilities to outsource all or a portion of their NGS operation such as cloud computing, bioinformatics pipelines, variant data management, and knowledge curation. Clinical pathology laboratories can electronically share diverse types of molecular data with reference laboratories, technology service providers, and/or regulatory agencies. Exchange of electronic molecular data allows laboratories to perform validation of rare diseases using foreign data, check the accuracy of their test results against benchmarks, and leverage in silico proficiency testing. This review covers the emerging subject of molecular telepathology, describes clinical use cases for the appropriate exchange of molecular data, and highlights key issues such as data integrity, interoperable formats for massive genomic datasets, security, malpractice and emerging regulations involved with this novel practice.

  20. Early Bashkirian Rugosa (Anthozoa) from the Donets Basin (Ukraine). Part 6. The Family Aulophyllidae Dybowski, 1873

    Science.gov (United States)

    Fedorowski, Jerzy

    2017-12-01

    Seven genera (one new), belonging to four subfamilies, seven named species (six new), four species left in open nomenclature and two specimens included in this paper as unnamed Aulophyllidae are described from strata ranging from the lowermost Bashkirian Limestone D510 to the lower Bashkirian Limestone F1. A new genus: Voragoaxum and six new species: Dibunophyllum medium, Dibunophylloides columnatus, D. paulus, D. similis, Voragoaxum cavum and Rozkowskia lenta are introduced. Comparison of the ontogeny of the earliest Bashkirian species of Nina Fedorowski, 2017a and Dibunophylloides Fomichev, 1953 suggest the derivation by descent of the Family Bothrophyllidae from the Subfamily Dibunophyllinae. This means that true bothrophylla are absent in the Mississippian strata of the Western European Province and, perhaps, in the contemporaneous strata of other areas as well.

  1. Immobilization of Candida rugosa lipase by adsorption-crosslinking onto corn husk

    Science.gov (United States)

    Nuraliyah, A.; Wijanarko, A.; Hermansyah, H.

    2018-04-01

    Corn husk is one of the agricutural waste that has not been used optimally. corn husk waste allows to be used as immobilized support for biocatalyst because it is easy to obtain, available abundant, renewable and easy to decompose. This research was conducted in two phases, namely the adsorption of enzyme immobilization on the support, followed by cross- linking between the enzyme and support through the addition of glutaraldehyde. The optimum conditions for cross-linked adsorption immobilization using support of corn husk were achieved at concentrations of 0,75 mg / ml at 4 hour reaction time. The biggest unit activity value is obtained at 2,37 U / g support through 0.5% glutaraldehyde addition.

  2. Acaulospora papillosa, a new mycorrhizal fungus from NE Brazil, and Acaulospora rugosa from Norway

    Czech Academy of Sciences Publication Activity Database

    Pereira, C. M. R.; Maia, L. C.; Sánchez-Castro, I.; Palenzuela, J.; Silva, D. K. A.; Sudová, Radka; Kolaříková, Zuzana; Rydlová, Jana; Čtvrtlíková, Martina; Goto, B. T.; Silva, G.A.; Oehl, F.

    2016-01-01

    Roč. 260, č. 1 (2016), s. 14-24 ISSN 1179-3155 R&D Projects: GA ČR GAP504/10/0781 Institutional support: RVO:67985939 ; RVO:60077344 Keywords : Acaulosporaceae * rainforest * arbuscular mycorrhiza Subject RIV: EF - Botanics; EH - Ecology, Behaviour (BC-A) Impact factor: 1.240, year: 2016

  3. HIV Molecular Immunology 2015

    Energy Technology Data Exchange (ETDEWEB)

    Yusim, Karina [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Korber, Bette Tina [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Brander, Christian [Institucio Catalana de Recerca i Estudis Avancats (ICREA), Barcelona (Spain); Barouch, Dan [Beth Israel Deaconess Medical Center, Boston, MA (United States). Division of Vaccine Research; de Boer, Rob [Utrecht University, Utrecht (Netherlands). Faculty of Biology; Haynes, Barton F. [Duke Univ., Durham, NC (United States). Duke Human Vaccine Institute and Departments of Medicine, Surgery and Immunology; Koup, Richard [National Inst. of Health (NIH), Bethesda, MD (United States). Vaccine Research Center; Moore, John P. [Cornell Univ., Ithaca, NY (United States). Weill Medical College; Walker, Bruce D. [Ragon Institute, Cambridge, MA (United States); Watkins, David [Wisconsin Regional Primate Research Center, Madison, WI (United States)

    2016-04-05

    The scope and purpose of the HIV molecular immunology database: HIV Molecular Immunology is a companion volume to HIV Sequence Compendium. This publication, the 2015 edition, is the PDF version of the web-based HIV Immunology Database (http://www.hiv.lanl.gov/ content/immunology/). The web interface for this relational database has many search options, as well as interactive tools to help immunologists design reagents and interpret their results. In the HIV Immunology Database, HIV-specific B-cell and T-cell responses are summarized and annotated. Immunological responses are divided into three parts, CTL, T helper, and antibody. Within these parts, defined epitopes are organized by protein and binding sites within each protein, moving from left to right through the coding regions spanning the HIV genome. We include human responses to natural HIV infections, as well as vaccine studies in a range of animal models and human trials. Responses that are not specifically defined, such as responses to whole proteins or monoclonal antibody responses to discontinuous epitopes, are summarized at the end of each protein section. Studies describing general HIV responses to the virus, but not to any specific protein, are included at the end of each part. The annotation includes information such as cross-reactivity, escape mutations, antibody sequence, TCR usage, functional domains that overlap with an epitope, immune response associations with rates of progression and therapy, and how specific epitopes were experimentally defined. Basic information such as HLA specificities for T-cell epitopes, isotypes of monoclonal antibodies, and epitope sequences are included whenever possible. All studies that we can find that incorporate the use of a specific monoclonal antibody are included in the entry for that antibody. A single T-cell epitope can have multiple entries, generally one entry per study. Finally, maps of all defined linear epitopes relative to the HXB2 reference proteins

  4. Optically controllable molecular logic circuits

    International Nuclear Information System (INIS)

    Nishimura, Takahiro; Fujii, Ryo; Ogura, Yusuke; Tanida, Jun

    2015-01-01

    Molecular logic circuits represent a promising technology for observation and manipulation of biological systems at the molecular level. However, the implementation of molecular logic circuits for temporal and programmable operation remains challenging. In this paper, we demonstrate an optically controllable logic circuit that uses fluorescence resonance energy transfer (FRET) for signaling. The FRET-based signaling process is modulated by both molecular and optical inputs. Based on the distance dependence of FRET, the FRET pathways required to execute molecular logic operations are formed on a DNA nanostructure as a circuit based on its molecular inputs. In addition, the FRET pathways on the DNA nanostructure are controlled optically, using photoswitching fluorescent molecules to instruct the execution of the desired operation and the related timings. The behavior of the circuit can thus be controlled using external optical signals. As an example, a molecular logic circuit capable of executing two different logic operations was studied. The circuit contains functional DNAs and a DNA scaffold to construct two FRET routes for executing Input 1 AND Input 2 and Input 1 AND NOT Input 3 operations on molecular inputs. The circuit produced the correct outputs with all possible combinations of the inputs by following the light signals. Moreover, the operation execution timings were controlled based on light irradiation and the circuit responded to time-dependent inputs. The experimental results demonstrate that the circuit changes the output for the required operations following the input of temporal light signals

  5. Structural Molecular Biology 2017 | SSRL

    Science.gov (United States)

    Highlights Training Workshops & Summer Schools Summer Students Structural Molecular Biology Illuminating experimental driver for structural biology research, serving the needs of a large number of academic and — Our Mission The SSRL Structural Molecular Biology program operates as an integrated resource and has

  6. Teaching Molecular Biology with Microcomputers.

    Science.gov (United States)

    Reiss, Rebecca; Jameson, David

    1984-01-01

    Describes a series of computer programs that use simulation and gaming techniques to present the basic principles of the central dogma of molecular genetics, mutation, and the genetic code. A history of discoveries in molecular biology is presented and the evolution of these computer assisted instructional programs is described. (MBR)

  7. Cardiovascular molecular imaging of apoptosis

    International Nuclear Information System (INIS)

    Wolters, S.L.; Reutelingsperger, C.P.M.; Corsten, M.F.; Hofstra, L.; Narula, J.

    2007-01-01

    Molecular imaging strives to visualise processes at the molecular and cellular level in vivo. Understanding these processes supports diagnosis and evaluation of therapeutic efficacy on an individual basis and thereby makes personalised medicine possible. Apoptosis is a well-organised mode of cell suicide that plays a role in cardiovascular diseases (CVD). Apoptosis is associated with loss of cardiomyocytes following myocardial infarction, atherosclerotic plaque instability, congestive heart failure and allograft rejection of the transplanted heart. Thus, apoptosis constitutes an attractive target for molecular imaging of CVD. Our current knowledge about the molecular players and mechanisms underlying apoptosis offers a rich palette of potential molecular targets for molecular imaging. However, only a few have been successfully developed so far. This review highlights aspects of the molecular machinery and biochemistry of apoptosis relevant to the development of molecular imaging probes. It surveys the role of apoptosis in four major areas of CVD and portrays the importance and future perspectives of apoptosis imaging. The annexin A5 imaging protocol is emphasised since it is the most advanced protocol to measure apoptosis in both preclinical and clinical studies. (orig.)

  8. CH2 molecular beam source

    International Nuclear Information System (INIS)

    Porter, R.A.R.; Grosser, A.E.

    1980-01-01

    A molecular beam source of CH 2 is described. Coaxial beams of methylene halide and alkali metal react and the mixture is formed into a molecular beam. Passage through a mechanical velocity selector rotating at a suitably high speed purifies the beam, separating light, fast CH 2 from heavier, slower contaminating species

  9. Molecular Structure of Nucleic Acids

    Indian Academy of Sciences (India)

    Molecular Structure of Nucleic Acids. A Structure for Deoxyribose Nucleic Acid. J. D. Watson and F. H. C. Crick. Medical Research Council Unit for the Study of the Molecular Structure of Biological. Systems, Cavendish Laboratory, Cambridge. April 2. We wish to suggest a structure for the salt of deoxyribose nucleic acid ...

  10. Peltier cooling in molecular junctions

    Science.gov (United States)

    Cui, Longji; Miao, Ruijiao; Wang, Kun; Thompson, Dakotah; Zotti, Linda Angela; Cuevas, Juan Carlos; Meyhofer, Edgar; Reddy, Pramod

    2018-02-01

    The study of thermoelectricity in molecular junctions is of fundamental interest for the development of various technologies including cooling (refrigeration) and heat-to-electricity conversion1-4. Recent experimental progress in probing the thermopower (Seebeck effect) of molecular junctions5-9 has enabled studies of the relationship between thermoelectricity and molecular structure10,11. However, observations of Peltier cooling in molecular junctions—a critical step for establishing molecular-based refrigeration—have remained inaccessible. Here, we report direct experimental observations of Peltier cooling in molecular junctions. By integrating conducting-probe atomic force microscopy12,13 with custom-fabricated picowatt-resolution calorimetric microdevices, we created an experimental platform that enables the unified characterization of electrical, thermoelectric and energy dissipation characteristics of molecular junctions. Using this platform, we studied gold junctions with prototypical molecules (Au-biphenyl-4,4'-dithiol-Au, Au-terphenyl-4,4''-dithiol-Au and Au-4,4'-bipyridine-Au) and revealed the relationship between heating or cooling and charge transmission characteristics. Our experimental conclusions are supported by self-energy-corrected density functional theory calculations. We expect these advances to stimulate studies of both thermal and thermoelectric transport in molecular junctions where the possibility of extraordinarily efficient energy conversion has been theoretically predicted2-4,14.

  11. Molecular motion in restricted geometries

    Indian Academy of Sciences (India)

    Molecular dynamics in restricted geometries is known to exhibit anomalous behaviour. Diffusion, translational or rotational, of molecules is altered significantly on confinement in restricted geometries. Quasielastic neutron scattering (QENS) offers a unique possibility of studying molecular motion in such systems. Both time ...

  12. From Molecular Biology to Biomedicine

    International Nuclear Information System (INIS)

    Salas, M.

    2009-01-01

    From Molecular Biology to Biomedicine. The well known molecular biologist Margarita Salas offered an informative conference at the CSN on progress in these areas since the discovery, more than half a century ago, of the structure of the molecule carrying genetic information, DNA, work that is having an enormous impact in areas such as biomedicine and foodstuff production. (Author)

  13. Dipole plasma in molecular crystals

    International Nuclear Information System (INIS)

    Kotel'nikov, Yu.E.; Kochelaev, B.I.

    1976-01-01

    Collective oscillations in a system of electric dipoles of molecular crystals are investigated. It has been proved in the exciton approximation that in an elementary cell of a molecular crystal with one molecule there may exist energy fluctuations of the ''dipole'' plasma, analogous to plasma oscillations in the charged Fermi liquid

  14. Molecular ecology of aquatic microbes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    Abstracts of reports are presented from a meeting on Molecular Ecology of Aquatic Microbes. Topics included: opportunities offered to aquatic ecology by molecular biology; the role of aquatic microbes in biogeochemical cycles; characterization of the microbial community; the effect of the environment on aquatic microbes; and the targeting of specific biological processes.

  15. Cardiovascular molecular imaging of apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Wolters, S.L.; Reutelingsperger, C.P.M. [Maastricht University, Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht (Netherlands); Corsten, M.F.; Hofstra, L. [Maastricht University, Department of Cardiology, Cardiovascular Research Institute Maastricht, P.O. Box 616, Maastricht (Netherlands); Narula, J. [University of California Irvine, Department of Cardiology, Irvine (United States)

    2007-06-15

    Molecular imaging strives to visualise processes at the molecular and cellular level in vivo. Understanding these processes supports diagnosis and evaluation of therapeutic efficacy on an individual basis and thereby makes personalised medicine possible. Apoptosis is a well-organised mode of cell suicide that plays a role in cardiovascular diseases (CVD). Apoptosis is associated with loss of cardiomyocytes following myocardial infarction, atherosclerotic plaque instability, congestive heart failure and allograft rejection of the transplanted heart. Thus, apoptosis constitutes an attractive target for molecular imaging of CVD. Our current knowledge about the molecular players and mechanisms underlying apoptosis offers a rich palette of potential molecular targets for molecular imaging. However, only a few have been successfully developed so far. This review highlights aspects of the molecular machinery and biochemistry of apoptosis relevant to the development of molecular imaging probes. It surveys the role of apoptosis in four major areas of CVD and portrays the importance and future perspectives of apoptosis imaging. The annexin A5 imaging protocol is emphasised since it is the most advanced protocol to measure apoptosis in both preclinical and clinical studies. (orig.)

  16. MOLECULARLY IMPRINTED POLYMER TECHNOLOGY: A ...

    African Journals Online (AJOL)

    dell

    Cross-linking ensures polymer rigidity that “freezes” the 3-D molecular architecture of the binding cavity when the ... molecular technology applications whose potential is still .... recognition element is responsible for the selective ... organic treatments, making them superior ... efficiency with which such materials may be.

  17. Development of molecular nuclear medicine

    International Nuclear Information System (INIS)

    Tang Ganghua

    2002-01-01

    The basic theory of molecular nuclear medicine is briefly introduced. The hot areas of molecular nuclear medicine including metabolic imaging and blood flow imaging, radioimmunoimaging and radioimmunotherapy, radioreceptor imaging and receptor-radioligand therapy, and imaging gene expression and gene radiation therapy are emphatically described

  18. Molecular Force Spectroscopy on Cells

    Science.gov (United States)

    Liu, Baoyu; Chen, Wei; Zhu, Cheng

    2015-04-01

    Molecular force spectroscopy has become a powerful tool to study how mechanics regulates biology, especially the mechanical regulation of molecular interactions and its impact on cellular functions. This force-driven methodology has uncovered a wealth of new information of the physical chemistry of molecular bonds for various biological systems. The new concepts, qualitative and quantitative measures describing bond behavior under force, and structural bases underlying these phenomena have substantially advanced our fundamental understanding of the inner workings of biological systems from the nanoscale (molecule) to the microscale (cell), elucidated basic molecular mechanisms of a wide range of important biological processes, and provided opportunities for engineering applications. Here, we review major force spectroscopic assays, conceptual developments of mechanically regulated kinetics of molecular interactions, and their biological relevance. We also present current challenges and highlight future directions.

  19. Handbook of Molecular Force Spectroscopy

    CERN Document Server

    Noy, Aleksandr

    2008-01-01

    "...Noy's Handbook of Molecular Force Spectroscopy is both a timely and useful summary of fundamental aspects of molecular force spectroscopy, and I believe it would make a worthwhile addition to any good scientific library. New research groups that are entering this field would be well advisedto study this handbook in detail before venturing into the exciting and challenging world of molecular force spectroscopy." Matthew F. Paige, University of Saskatchewan, Journal of the American Chemical Society Modern materials science and biophysics are increasingly focused on studying and controlling intermolecular interactions on the single-molecule level. Molecular force spectroscopy was developed in the past decade as the result of several unprecedented advances in the capabilities of modern scientific instrumentation, and defines a number of techniques that use mechanical force measurements to study interactions between single molecules and molecular assemblies in chemical and biological systems. Examples of these...

  20. Chirality in molecular collision dynamics

    Science.gov (United States)

    Lombardi, Andrea; Palazzetti, Federico

    2018-02-01

    Chirality is a phenomenon that permeates the natural world, with implications for atomic and molecular physics, for fundamental forces and for the mechanisms at the origin of the early evolution of life and biomolecular homochirality. The manifestations of chirality in chemistry and biochemistry are numerous, the striking ones being chiral recognition and asymmetric synthesis with important applications in molecular sciences and in industrial and pharmaceutical chemistry. Chiral discrimination phenomena, due to the existence of two enantiomeric forms, very well known in the case of interaction with light, but still nearly disregarded in molecular collision studies. Here we review some ideas and recent advances about the role of chirality in molecular collisions, designing and illustrating molecular beam experiments for the demonstration of chiral effects and suggesting a scenario for a stereo-directional origin of chiral selection.

  1. Molecular electron affinities

    International Nuclear Information System (INIS)

    Fukuda, E.K.

    1983-01-01

    Molecular electron affinities have historically been difficult quantities to measure accurately. These difficulties arise from differences in structure between the ion and neutral as well as the existence of excited negative ion states. To circumvent these problems, relative electron affinities were determined in this dissertation by studying equilibrium electron transfer reactions using a pulsed ion cyclotron resonance (ICR) spectrometer. Direct measurement of ion and neutral concentrations for reactions of the general type, A - + B = B - + A, allow calculation of the equilibrium constant and, therefore, the free energy change. The free energy difference is related to the difference in electron affinities between A and B. A relative electron affinity scale covering a range of about 45 kcal/mol was constructed with various substituted p-benzoquinones, nitrobenzenes, anhydrides, and benzophenones. To assign absolute electron affinities, various species with accurately known electron affinities are tied to the scale via ion-cyclotron double resonance bracketing techniques. After the relative scale is anchored to these species with well-known electron affinities, the scale is then used as a check on other electron affinity values as well as generating new electron affinity values. Many discrepancies were found between the electron affinities measured using the ICR technique and previous literature determinations

  2. Molecular analysis of thymoma.

    Directory of Open Access Journals (Sweden)

    Sunil Badve

    Full Text Available Histologic classification of thymomas has significant limitations with respect to both subtype definitions and consistency. In order to better understand the biology of the disease processes, we performed whole genome gene expression analysis. RNA was extracted from fresh frozen tumors from 34 patients with thymomas and followup data was available. Using the Illumina BeadStudio® platform and Human Ref-8 Beadchip, gene expression data was analyzed with Partek Genomics Suite®, and Ingenuity Pathways Analysis (IPA. Unsupervised clustering of gene expression data, representing one of the largest series in literature, resulted in identification of four molecular clusters of tumors (C1-C4, which correlated with histology (P = 0.002. However, neither histology nor clusters correlated with clinical outcomes. Correlation of gene expression data with clinical data showed that a number of genes were associated with either advanced stage at diagnosis or development of recurrence or metastases. The top pathways associated with metastases were amino acid metabolisms, biosynthesis of steroids and glycosphingolipids, cell cycle checkpoint proteins and Notch signaling. The differential expression of some of the top genes related to both metastases and stage was confirmed by RT-PCR in all cases of metastases and matched nonmetastatic cases. A number of potential candidates for therapeutics were also identified.

  3. Molecular diagnostics of periodontitis.

    Science.gov (United States)

    Korona-Głowniak, Izabela; Siwiec, Radosław; Berger, Marcin; Malm, Anna; Szymańska, Jolanta

    2017-01-28

    The microorganisms that form dental plaque are the main cause of periodontitis. Their identification and the understanding of the complex relationships and interactions that involve these microorganisms, environmental factors and the host's health status enable improvement in diagnostics and targeted therapy in patients with periodontitis. To this end, molecular diagnostics techniques (both techniques based on the polymerase chain reaction and those involving nucleic acid analysis via hybridization) come increasingly into use. On the basis of a literature review, the following methods are presented: polymerase chain reaction (PCR), real-time polymerase chain reaction (real-time PCR), 16S rRNA-encoding gene sequencing, checkerboard and reverse-capture checkerboard hybridization, microarrays, denaturing gradient gel electrophoresis (DGGE), temperature gradient gel electrophoresis (TGGE), as well as terminal restriction fragment length polymorphism (TRFLP) and next generation sequencing (NGS). The advantages and drawbacks of each method in the examination of periopathogens are indicated. The techniques listed above allow fast detection of even small quantities of pathogen present in diagnostic material and prove particularly useful to detect microorganisms that are difficult or impossible to grow in a laboratory.

  4. Molecular diagnostics of periodontitis

    Directory of Open Access Journals (Sweden)

    Izabela Korona-Głowniak

    2017-01-01

    Full Text Available The microorganisms that form dental plaque are the main cause of periodontitis. Their identification and the understanding of the complex relationships and interactions that involve these microorganisms, environmental factors and the host’s health status enable improvement in diagnostics and targeted therapy in patients with periodontitis. To this end, molecular diagnostics techniques (both techniques based on the polymerase chain reaction and those involving nucleic acid analysis via hybridization come increasingly into use. On the basis of a literature review, the following methods are presented: polymerase chain reaction (PCR, real-time polymerase chain reaction (real-time PCR, 16S rRNA-encoding gene sequencing, checkerboard and reverse-capture checkerboard hybridization, microarrays, denaturing gradient gel electrophoresis (DGGE, temperature gradient gel electrophoresis (TGGE, as well as terminal restriction fragment length polymorphism (TRFLP and next generation sequencing (NGS. The advantages and drawbacks of each method in the examination of periopathogens are indicated. The techniques listed above allow fast detection of even small quantities of pathogen present in diagnostic material and prove particularly useful to detect microorganisms that are difficult or impossible to grow in a laboratory.

  5. A molecular noise generator

    International Nuclear Information System (INIS)

    Lu Ting; Ferry, Michael; Hasty, Jeff; Weiss, Ron

    2008-01-01

    Recent studies have demonstrated that intracellular variations in the rate of gene expression are of fundamental importance to cellular function and development. While such 'noise' is often considered detrimental in the context of perturbing genetic systems, it can be beneficial in processes such as species diversification and facilitation of evolution. A major difficulty in exploring such effects is that the magnitude and spectral properties of the induced variations arise from some intrinsic cellular process that is difficult to manipulate. Here, we present two designs of a molecular noise generator that allow for the flexible modulation of the noise profile of a target gene. The first design uses a dual-signal mechanism that enables independent tuning of the mean and variability of an output protein. This is achieved through the combinatorial control of two signals that regulate transcription and translation separately. We then extend the design to allow for DNA copy-number regulation, which leads to a wider tuning spectrum for the output molecule. To gain a deeper understanding of the circuit's functionality in a realistic environment, we introduce variability in the input signals in order to ascertain the degree of noise induced by the control process itself. We conclude by illustrating potential applications of the noise generator, demonstrating how it could be used to ascertain the robust or fragile properties of a genetic circuit

  6. Molecular nuclear cardiac imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Soo; Paeng, Jin Chul [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of)

    2004-04-01

    Molecular nuclear cardiac imaging has included Tc-99m Annexin imaging to visualize myocardial apoptosis, but is now usually associated with gene therapy and cell-based therapy. Cardiac gene therapy was not successful so far but cardiac reporter gene imaging was made possible using HSV-TK (herpes simplex virus thymidine kinase) and F-18 FHBG (fluoro-hydroxymethylbutyl guanine) or I-124 FIAU (fluoro-deoxyiodo-arabino-furanosyluracil). Gene delivery was performed by needle injection with or without catheter guidance. TK expression did not last longer than 2 weeks in myocardium. Cell-based therapy of ischemic heart or failing heart looks promising, but biodistribution and differentiation of transplanted cells are not known. Reporter genes can be transfected to the stem/progenitor cells and cells containing these genes can be transplanted to the recipients using catheter-based purging or injection. Repeated imaging should be available and if promoter are varied to let express reporter transgenes, cellular (trans)differentiation can be studied. NIS (sodium iodide symporter) or D2R receptor genes are promising in this aspect.

  7. Superradiance From Molecular Nanomagnets

    Science.gov (United States)

    Chudnovsky, Eugene M.

    2003-03-01

    Magnetic dipolar transitions in individual magnetic molecules occur with a very low probability. However, typical wavelengths of the corresponding electromagnetic radiation are in the millimeter range, that is, comparable to the crystal size. This may result in the superradiance: The coherent emission of the electromagnetic radiation by the entire crystal, with the rate increased by the total number of molecules as compared to the rate of the individual emission. Rigorous theory of the superradiant resonant magnetic relaxation will be presented, that generalizes the Landau-Zener effect for the case of a macroscopic number of magnetic molecules coupled through the electromagnetic radiation [1]. Possible evidence of coherent electromagnetic effects in crystals of molecular nanomagnets placed inside a resonant cavity will be reported [2]. (This work has been supported by the NSF grant No. DMR-9978882.) [1] E. M. Chudnovsky and D. A. Garanin, Phys. Rev. Lett. 89, 157201 (7 Oct 2002). [2] J. Tejada, E. M. Chudnovsky, R. Amigo, and J. M. Hernandez, cond-mat/0210340 (16 Oct 2002).

  8. Molecular screening in galactosemia

    Energy Technology Data Exchange (ETDEWEB)

    Elsas, L.J.; Singh, R.; Fernhoff, P.M. [Emory Univ., Atlanta, GA (United States)] [and others

    1994-09-01

    Classical galactosemia (G/G) is caused by the absence of galactose-1-phosphate uridyl transferase (GALT) activity while the Duarte allele produces partial impairment and a specific biochemical phenotype. Cloning and sequencing of the human GALT gene has enabled the identification of prevalent mutations for both Classical and Duarte alleles. The G allele is caused by a Q188R codon mutation in exon 6 in 70% of a Caucasian population while the D allele is caused by an N134D codon mutation in exon 10. Since the Q188R sequence creates a new Hpa II site and the N314D sequence creates a new Sin I site, it is relatively easy to screen for both mutations by multiplex PCR and restriction digest. Here we describe a method for detection of new mutations producing impaired GALT. Patient DNAs are subjected to SSCP (single strand conformational polymorphism) analysis of their 11 GALT exons. Direct sequencing of the exons targeted by SSCP has revealed many codon changes: IVSC 956 (a splice acceptor site loss), S135L, V151A, E203K, A320T, and Y323D. Two of these codon changes, V151A and S135L, have been confirmed as mutations by finding impaired GALT activity in a yeast expression system. We conclude that molecular screening of GALT DNA will clarify the structural biology of GALT and the pathophysiology of galactosemia.

  9. Radically enhanced molecular recognition

    KAUST Repository

    Trabolsi, Ali; Khashab, Niveen M.; Fahrenbach, Albert C.; Friedman, Douglas C.; Colvin, Michael T.; Coti, Karla K.; Bení tez, Diego S.; Tkatchouk, Ekaterina; Olsen, John Carl; Belowich, Matthew E.; Carmieli, Raanan; Khatib, Hussam A.; Goddard, William Andrew III; Wasielewski, Michael R.; Stoddart, Fraser Fraser Raser

    2009-01-01

    The tendency for viologen radical cations to dimerize has been harnessed to establish a recognition motif based on their ability to form extremely strong inclusion complexes with cyclobis(paraquat-p-phenylene) in its diradical dicationic redox state. This previously unreported complex involving three bipyridinium cation radicals increases the versatility of host-guest chemistry, extending its practice beyond the traditional reliance on neutral and charged guests and hosts. In particular, transporting the concept of radical dimerization into the field of mechanically interlocked molecules introduces a higher level of control within molecular switches and machines. Herein, we report that bistable and tristable [2]rotaxanes can be switched by altering electrochemical potentials. In a tristable [2]rotaxane composed of a cyclobis(paraquat-p-phenylene) ring and a dumbbell with tetrathiafulvalene, dioxynaphthalene and bipyridinium recognition sites, the position of the ring can be switched. On oxidation, it moves from the tetrathiafulvalene to the dioxynaphthalene, and on reduction, to the bipyridinium radical cation, provided the ring is also reduced simultaneously to the diradical dication. © 2010 Macmillan Publishers Limited. All rights reserved.

  10. Molecular physiology of seeds

    International Nuclear Information System (INIS)

    Hajduch, M.

    2014-05-01

    Plant development is well described. However, full understanding of the regulation of processes associated with plant development is still missing. Present Dr.Sc. thesis advances our understanding of the regulation of plant development by quantitative proteomics analyses of seed development of soybean, canola, castor, flax, and model plant arabidopsis in control and environmentally challenged environments. The analysis of greenhouse-grown soybean, canola, castor, and arabidospis provided complex characterization of metabolic processes during seed development, for instance, of carbon assimilation into fatty acids. Furthermore, the analyses of soybean and flax grown in Chernobyl area provided in-depth characterization of seed development in radio-contaminated environment. Soybean and flax were altered by radio-contaminated environment in different way. However, these alterations resulted into modifications in seed oil content. Further analyses showed that soybean and flax possess alterations of carbon metabolism in cytoplasm and plastids along with increased activity of photosynthetic apparatus. Our present experiments are focused on further characterization of molecular bases that might be responsible for alterations of seed oil content in Chernobyl grown plants. (author)

  11. Molecular methods for biofilms

    KAUST Repository

    Ferrera, Isabel; Balagué , Vanessa; Voolstra, Christian R.; Aranda, Manuel; Bayer, Till; Abed, Raeid M.M.; Dobretsov, Sergey; Owens, Sarah M.; Wilkening, Jared; Fessler, Jennifer L.; Gilbert, Jack A.

    2014-01-01

    This chapter deals with both classical and modern molecular methods that can be useful for the identification of microorganisms, elucidation and comparison of microbial communities, and investigation of their diversity and functions. The most important and critical steps necessary for all molecular methods is DNA isolation from microbial communities and environmental samples; these are discussed in the first part. The second part provides an overview over DNA polymerase chain reaction (PCR) amplification and DNA sequencing methods. Protocols and analysis software as well as potential pitfalls associated with application of these methods are discussed. Community fingerprinting analyses that can be used to compare multiple microbial communities are discussed in the third part. This part focuses on Denaturing Gradient Gel Electrophoresis (DGGE), Terminal Restriction Fragment Length Polymorphism (T-RFLP) and Automated rRNA Intergenic Spacer Analysis (ARISA) methods. In addition, classical and next-generation metagenomics methods are presented. These are limited to bacterial artificial chromosome and Fosmid libraries and Sanger and next-generation 454 sequencing, as these methods are currently the most frequently used in research. Isolation of nucleic acids: This chapter discusses, the most important and critical steps necessary for all molecular methods is DNA isolation from microbial communities and environmental samples. Nucleic acid isolation methods generally include three steps: cell lysis, removal of unwanted substances, and a final step of DNA purification and recovery. The first critical step is the cell lysis, which can be achieved by enzymatic or mechanical procedures. Removal of proteins, polysaccharides and other unwanted substances is likewise important to avoid their interference in subsequent analyses. Phenol-chloroform-isoamyl alcohol is commonly used to recover DNA, since it separates nucleic acids into an aqueous phase and precipitates proteins and

  12. Molecular methods for biofilms

    KAUST Repository

    Ferrera, Isabel

    2014-08-30

    This chapter deals with both classical and modern molecular methods that can be useful for the identification of microorganisms, elucidation and comparison of microbial communities, and investigation of their diversity and functions. The most important and critical steps necessary for all molecular methods is DNA isolation from microbial communities and environmental samples; these are discussed in the first part. The second part provides an overview over DNA polymerase chain reaction (PCR) amplification and DNA sequencing methods. Protocols and analysis software as well as potential pitfalls associated with application of these methods are discussed. Community fingerprinting analyses that can be used to compare multiple microbial communities are discussed in the third part. This part focuses on Denaturing Gradient Gel Electrophoresis (DGGE), Terminal Restriction Fragment Length Polymorphism (T-RFLP) and Automated rRNA Intergenic Spacer Analysis (ARISA) methods. In addition, classical and next-generation metagenomics methods are presented. These are limited to bacterial artificial chromosome and Fosmid libraries and Sanger and next-generation 454 sequencing, as these methods are currently the most frequently used in research. Isolation of nucleic acids: This chapter discusses, the most important and critical steps necessary for all molecular methods is DNA isolation from microbial communities and environmental samples. Nucleic acid isolation methods generally include three steps: cell lysis, removal of unwanted substances, and a final step of DNA purification and recovery. The first critical step is the cell lysis, which can be achieved by enzymatic or mechanical procedures. Removal of proteins, polysaccharides and other unwanted substances is likewise important to avoid their interference in subsequent analyses. Phenol-chloroform-isoamyl alcohol is commonly used to recover DNA, since it separates nucleic acids into an aqueous phase and precipitates proteins and

  13. Molecular factors in migraine

    Science.gov (United States)

    Kowalska, Marta; Prendecki, Michał; Kozubski, Wojciech; Lianeri, Margarita; Dorszewska, Jolanta

    2016-01-01

    Migraine is a common neurological disorder that affects 11% of adults worldwide. This disease most likely has a neurovascular origin. Migraine with aura (MA) and more common form - migraine without aura (MO) – are the two main clinical subtypes of disease. The exact pathomechanism of migraine is still unknown, but it is thought that both genetic and environmental factors are involved in this pathological process. The first genetic studies of migraine were focused on the rare subtype of MA: familial hemiplegic migraine (FHM). The genes analysed in familial and sporadic migraine are: MTHFR, KCNK18, HCRTR1, SLC6A4, STX1A, GRIA1 and GRIA3. It is possible that migraine is a multifactorial disease with polygenic influence. Recent studies have shown that the pathomechanisms of migraine involves both factors responsible for immune response and oxidative stress such as: cytokines, tyrosine metabolism, homocysteine; and factors associated with pain transmission and emotions e.g.: serotonin, hypocretin-1, calcitonin gene-related peptide, glutamate. The correlations between genetic variants of the HCRTR1 gene, the polymorphism 5-HTTLPR and hypocretin-1, and serotonin were observed. It is known that serotonin inhibits the activity of hypocretin neurons and may affect the appearance of the aura during migraine attack. The understanding of the molecular mechanisms of migraine, including genotype-phenotype correlations, may contribute to finding markers important for the diagnosis and treatment of this disease. PMID:27191890

  14. Radically enhanced molecular recognition

    KAUST Repository

    Trabolsi, Ali

    2009-12-17

    The tendency for viologen radical cations to dimerize has been harnessed to establish a recognition motif based on their ability to form extremely strong inclusion complexes with cyclobis(paraquat-p-phenylene) in its diradical dicationic redox state. This previously unreported complex involving three bipyridinium cation radicals increases the versatility of host-guest chemistry, extending its practice beyond the traditional reliance on neutral and charged guests and hosts. In particular, transporting the concept of radical dimerization into the field of mechanically interlocked molecules introduces a higher level of control within molecular switches and machines. Herein, we report that bistable and tristable [2]rotaxanes can be switched by altering electrochemical potentials. In a tristable [2]rotaxane composed of a cyclobis(paraquat-p-phenylene) ring and a dumbbell with tetrathiafulvalene, dioxynaphthalene and bipyridinium recognition sites, the position of the ring can be switched. On oxidation, it moves from the tetrathiafulvalene to the dioxynaphthalene, and on reduction, to the bipyridinium radical cation, provided the ring is also reduced simultaneously to the diradical dication. © 2010 Macmillan Publishers Limited. All rights reserved.

  15. Molecular nuclear cardiac imaging

    International Nuclear Information System (INIS)

    Lee, Dong Soo; Paeng, Jin Chul

    2004-01-01

    Molecular nuclear cardiac imaging has included Tc-99m Annexin imaging to visualize myocardial apoptosis, but is now usually associated with gene therapy and cell-based therapy. Cardiac gene therapy was not successful so far but cardiac reporter gene imaging was made possible using HSV-TK (herpes simplex virus thymidine kinase) and F-18 FHBG (fluoro-hydroxymethylbutyl guanine) or I-124 FIAU (fluoro-deoxyiodo-arabino-furanosyluracil). Gene delivery was performed by needle injection with or without catheter guidance. TK expression did not last longer than 2 weeks in myocardium. Cell-based therapy of ischemic heart or failing heart looks promising, but biodistribution and differentiation of transplanted cells are not known. Reporter genes can be transfected to the stem/progenitor cells and cells containing these genes can be transplanted to the recipients using catheter-based purging or injection. Repeated imaging should be available and if promoter are varied to let express reporter transgenes, cellular (trans)differentiation can be studied. NIS (sodium iodide symporter) or D2R receptor genes are promising in this aspect

  16. Molecular dynamics of bacteriorhodopsin.

    Science.gov (United States)

    Lupo, J A; Pachter, R

    1997-02-01

    A model of bacteriorhodopsin (bR), with a retinal chromophore attached, has been derived for a molecular dynamics simulation. A method for determining atomic coordinates of several ill-defined strands was developed using a structure prediction algorithm based on a sequential Kalman filter technique. The completed structure was minimized using the GROMOS force field. The structure was then heated to 293 K and run for 500 ps at constant temperature. A comparison with the energy-minimized structure showed a slow increase in the all-atom RMS deviation over the first 200 ps, leveling off to approximately 2.4 A relative to the starting structure. The final structure yielded a backbone-atom RMS deviation from the crystallographic structure of 2.8 A. The residue neighbors of the chromophore atoms were followed as a function of time. The set of persistent near-residue neighbors supports the theory that differences in pKa values control access to the Schiff base proton, rather than formation of a counterion complex.

  17. New concepts for molecular magnets

    Science.gov (United States)

    Pilawa, Bernd

    1999-03-01

    Miller and Epstein (1994) define molecular magnets as magnetic materials which are prepared by the low-temperature methods of the preparative chemistry. This definition includes molecular crystals of neutral radicals, radical salts and charge transfer complexes as well as metal complexes and polymers with unpaired spins (Dormann 1995). The challenge of molecular magnets consists in tailoring magnetic properties by specific modifications of the molecular units. The combination of magnetism with mechanical or electrical properties of molecular compounds promise materials of high technical interest (Gatteschi 1994a and 1994b, Möhwald 1996) and both the chemical synthesis of new molecular materials with magnetic properties as well as the physical investigation and explanation of these properties is important, in order to achieve any progress. This work deals with the physical characterization of the magnetic properties of molecular materials. It is organized as follows. In the first part molecular crystals of neutral radicals are studied. After briefly discussing the general magnetic properties of these materials and after an overview over the physical principles of exchange interaction between organic radicals I focus on the interplay between the crystallographic structure and the magnetic properties of various derivatives of the verdazyl and nitronyl nitroxide radicals. The magnetic properties of metal complexes are the subject of the second part. After an overview over the experimental and theoretical tools which are used for the investigation of the magnetic properties I shortly discuss the exchange coupling of transition metal ions and the magnetic properties of complexes of two and three metal ions. Special emphasis is given to spin cluster compounds. Spin cluster denote complexes of many magnetic ions. They are attractive as building blocks of molecular magnets as well as magnetic model compounds for the study of spin frustration, molecular super

  18. Department of Molecular Biology

    International Nuclear Information System (INIS)

    Kusmierek, J.

    1998-01-01

    Full text. The majority of our studies are centered on (i) mechanisms of mutagenesis and DNA repair (including MFD) in Escherichia coli, M13, and lambda phages; (ii) inhibitory and miscoding properties of modified bases in DNA; (iii) synthesis and properties of pyrimidine nucleosides and nucleotide analogues with potential anti-tumor, anti-virus and anti-parasite activities, including their conformation and substrate/inhibitor properties in some enzyme systems of relevance to chemotherapy; (iv) molecular mechanisms of PUVA (psoralen + UVA) treatment in psoriasis photo-chemotherapy in particular its action on cell membrane; (v) specificity and methods for assays of N-alkyl-purine DNA glycosylase. The spectrum of mutagens tested includes: MMS, DMS, ultraviolet or halogen light and hydroxyl radicals. The enzymes and repair systems investigated include: DNA polymerases and the proofreading activity of DNA pol III, UvrABC-endonuclease, mismatch repair system, and methyl DNA glycosylases. Much attention is focussed on the role of UmuDC proteins in mutagenesis (dependent and independent on DNA replication) and DNA repair, and on the effect of the Tn10 transposon on the survival and mutation frequency of halogen light irradiated bacteria. A new class of nucleosides containing C(2)-hydroxymethyl-ribose (hamamelose) was synthesized, and it was found that uracil and 5-fluorouracil derivatives show a significant antitumor activity. It was found that 2CDA (2-deoxy-2-chloro-adenosine) an anti-lymphoid drug does not induce mutations, when incorporated into DNA, but significantly inhibits DNA replication. In studies with oxidized M13 DNA it was found that Fapy- (formamidopyrimidine)-residues in DNA selectively inhibits DNA synthesis, and the effect depends on the neighboring sequences and the DNA polymerase tested. Highly unstable derivatives of lecithin-psoralen adducts were characterized and their role in PUVA photochemotherapy is being studied. (author)

  19. Molecular Diagnosis of Phytoplasmas

    Directory of Open Access Journals (Sweden)

    C. Marzachì

    2004-08-01

    Full Text Available Phytoplasmas are wall-less prokaryotes associated with diseases in numerous plant species worldwide. In nature they are transmitted by phloem-sucking insects. Yellowing, decline, witches’ broom, leaf curl, floral virescence and phyllody are the most conspicuous symptoms associated with phytoplasmas, although infections are sometimes asymptomatic. Since phytoplasmas cannot be cultured in vitro, molecular techniques are needed for their diagnosis and characterization. The titer of phytoplasma cells in the phloem of infected plants may vary according to the season and the plant species, and it is often very low in woody hosts. Different DNA extraction procedures have therefore been tried out to obtain phytoplasma DNA at a concentration and purity high enough for effective diagnosis. DNA/DNA hybridization methods were reported in the nineties to be appropriate for the detection of phytoplasmas, but at present PCR is considered the most suitable. Universal and group-specific primers have been designed on the rRNA operon of the phytoplasma genome and on plasmid sequences. RFLP analysis of the obtained amplicons has classified these pathogens into major 16Sr RNA groups. Group-specific primers have also been designed on other genomic sequences. PCR is a very sensitive technique, but due to the low titre of phytoplasmas a further increase in sensitivity may be required for accurate diagnosis. This is routinely obtained with a second round of PCR (nested PCR. The drawback of nested PCR is that there is a greater chance of obtaining false positives due to contamination. Many authors have therefore developed protocols based on hybridization (PCR/dot blot or serological approaches (PCR/ELISA to increase the sensitivity and specificity of the direct PCR, reducing the risks due to nested PCR. Real time PCR protocols may also improve the sensitivity and specificity of the direct PCR assay.

  20. HIV Molecular Immunology 2014

    Energy Technology Data Exchange (ETDEWEB)

    Yusim, Karina [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Korber, Bette Tina Marie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Barouch, Dan [Beth Israel Deaconess Medical Center, Boston, MA (United States); Koup, Richard [Vaccine Research Center National Institutes of Health (United States); de Boer, Rob [Utrecht Univ. (Netherlands). Dept. of Biology; Moore, John P. [Cornell Univ., Ithaca, NY (United States). Weill Medical College; Brander, Christian [Institucioi Catalana de Recerca i Estudis Avancats (ICREA), Barcelona (Spain); Haynes, Barton F. [Duke Univ., Durham, NC (United States). Duke Human Vaccine Institute and Departments of Medicine, Surgery and Immunology; Walker, Bruce D. [Ragon Institute of Massachusetts General Hospital, Cambridge, MA (United States); Harvard Univ., Cambridge, MA (United States); Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2015-02-03

    HIV Molecular Immunology is a companion volume to HIV Sequence Compendium. This publication, the 2014 edition, is the PDF version of the web-based HIV Immunology Database (http://www.hiv.lanl.gov/content/immunology/). The web interface for this relational database has many search options, as well as interactive tools to help immunologists design reagents and interpret their results. In the HIV Immunology Database, HIV-specific B-cell and T-cell responses are summarized and annotated. Immunological responses are divided into three parts, CTL, T helper, and antibody. Within these parts, defined epitopes are organized by protein and binding sites within each protein, moving from left to right through the coding regions spanning the HIV genome. We include human responses to natural HIV infections, as well as vaccine studies in a range of animal models and human trials. Responses that are not specifically defined, such as responses to whole proteins or monoclonal antibody responses to discontinuous epitopes, are summarized at the end of each protein section. Studies describing general HIV responses to the virus, but not to any specific protein, are included at the end of each part. The annotation includes information such as crossreactivity, escape mutations, antibody sequence, TCR usage, functional domains that overlap with an epitope, immune response associations with rates of progression and therapy, and how specific epitopes were experimentally defined. Basic information such as HLA specificities for T-cell epitopes, isotypes of monoclonal antibodies, and epitope sequences are included whenever possible. All studies that we can find that incorporate the use of a specific monoclonal antibody are included in the entry for that antibody. A single T-cell epitope can have multiple entries, generally one entry per study. Finally, maps of all defined linear epitopes relative to the HXB2 reference proteins are provided.

  1. Magnetohydrodynamic Models of Molecular Tornadoes

    Science.gov (United States)

    Au, Kelvin; Fiege, Jason D.

    2017-07-01

    Recent observations near the Galactic Center (GC) have found several molecular filaments displaying striking helically wound morphology that are collectively known as molecular tornadoes. We investigate the equilibrium structure of these molecular tornadoes by formulating a magnetohydrodynamic model of a rotating, helically magnetized filament. A special analytical solution is derived where centrifugal forces balance exactly with toroidal magnetic stress. From the physics of torsional Alfvén waves we derive a constraint that links the toroidal flux-to-mass ratio and the pitch angle of the helical field to the rotation laws, which we find to be an important component in describing the molecular tornado structure. The models are compared to the Ostriker solution for isothermal, nonmagnetic, nonrotating filaments. We find that neither the analytic model nor the Alfvén wave model suffer from the unphysical density inversions noted by other authors. A Monte Carlo exploration of our parameter space is constrained by observational measurements of the Pigtail Molecular Cloud, the Double Helix Nebula, and the GC Molecular Tornado. Observable properties such as the velocity dispersion, filament radius, linear mass, and surface pressure can be used to derive three dimensionless constraints for our dimensionless models of these three objects. A virial analysis of these constrained models is studied for these three molecular tornadoes. We find that self-gravity is relatively unimportant, whereas magnetic fields and external pressure play a dominant role in the confinement and equilibrium radial structure of these objects.

  2. SOYBEAN - MOLECULAR ASPECTS OF BREEDING

    Directory of Open Access Journals (Sweden)

    Aleksandra Sudarić

    2012-12-01

    Full Text Available The book Soybean: Molecular Aspects of Breeding focuses recent progress in our understanding of the genetics and molecular biology of soybean. This book is divided into four parts and contains 22 chapters. Part I, Molecular Biology and Biotechnology focuses advances in molecular biology and laboratory procedures that have been developed recently to manipulate DNA. Part II, Breeding for abiotic stress covers proteomics approaches form as a powerful tool for investigating the molecular mechanisms of the plant responses to various types of abiotic stresses. Part III, Breeding for biotic stress addresses issues related to application of molecular based strategies in order to increase soybean resistance to various biotic factors. Part IV, Recent Technology reviews recent technologies into the realm of soybean monitoring, processing and product use. While the information accumulated in this book is of primary interest for plant breeders, valuable insights are also offered to agronomists, molecular biologists, physiologists, plant pathologists, food scientists and students. The book is a result of efforts made by many experts from different countries (USA, Japan, Croatia, Serbia, China, Canada, Malawi, Iran, Hong Kong, Brasil, Mexico.

  3. Magnetohydrodynamic Models of Molecular Tornadoes

    Energy Technology Data Exchange (ETDEWEB)

    Au, Kelvin; Fiege, Jason D., E-mail: fiege@physics.umanitoba.ca [Department of Physics and Astronomy, University of Manitoba Winnipeg, MB R3T 2N2 (Canada)

    2017-07-10

    Recent observations near the Galactic Center (GC) have found several molecular filaments displaying striking helically wound morphology that are collectively known as molecular tornadoes. We investigate the equilibrium structure of these molecular tornadoes by formulating a magnetohydrodynamic model of a rotating, helically magnetized filament. A special analytical solution is derived where centrifugal forces balance exactly with toroidal magnetic stress. From the physics of torsional Alfvén waves we derive a constraint that links the toroidal flux-to-mass ratio and the pitch angle of the helical field to the rotation laws, which we find to be an important component in describing the molecular tornado structure. The models are compared to the Ostriker solution for isothermal, nonmagnetic, nonrotating filaments. We find that neither the analytic model nor the Alfvén wave model suffer from the unphysical density inversions noted by other authors. A Monte Carlo exploration of our parameter space is constrained by observational measurements of the Pigtail Molecular Cloud, the Double Helix Nebula, and the GC Molecular Tornado. Observable properties such as the velocity dispersion, filament radius, linear mass, and surface pressure can be used to derive three dimensionless constraints for our dimensionless models of these three objects. A virial analysis of these constrained models is studied for these three molecular tornadoes. We find that self-gravity is relatively unimportant, whereas magnetic fields and external pressure play a dominant role in the confinement and equilibrium radial structure of these objects.

  4. Spiers Memorial Lecture. Molecular mechanics and molecular electronics.

    Science.gov (United States)

    Beckman, Robert; Beverly, Kris; Boukai, Akram; Bunimovich, Yuri; Choi, Jang Wook; DeIonno, Erica; Green, Johnny; Johnston-Halperin, Ezekiel; Luo, Yi; Sheriff, Bonnie; Stoddart, Fraser; Heath, James R

    2006-01-01

    We describe our research into building integrated molecular electronics circuitry for a diverse set of functions, and with a focus on the fundamental scientific issues that surround this project. In particular, we discuss experiments aimed at understanding the function of bistable rotaxane molecular electronic switches by correlating the switching kinetics and ground state thermodynamic properties of those switches in various environments, ranging from the solution phase to a Langmuir monolayer of the switching molecules sandwiched between two electrodes. We discuss various devices, low bit-density memory circuits, and ultra-high density memory circuits that utilize the electrochemical switching characteristics of these molecules in conjunction with novel patterning methods. We also discuss interconnect schemes that are capable of bridging the micrometre to submicrometre length scales of conventional patterning approaches to the near-molecular length scales of the ultra-dense memory circuits. Finally, we discuss some of the challenges associated with fabricated ultra-dense molecular electronic integrated circuits.

  5. Photoelectron photoion molecular beam spectroscopy

    International Nuclear Information System (INIS)

    Trevor, D.J.

    1980-12-01

    The use of supersonic molecular beams in photoionization mass spectroscopy and photoelectron spectroscopy to assist in the understanding of photoexcitation in the vacuum ultraviolet is described. Rotational relaxation and condensation due to supersonic expansion were shown to offer new possibilities for molecular photoionization studies. Molecular beam photoionization mass spectroscopy has been extended above 21 eV photon energy by the use of Stanford Synchrotron Radiation Laboratory (SSRL) facilities. Design considerations are discussed that have advanced the state-of-the-art in high resolution vuv photoelectron spectroscopy. To extend gas-phase studies to 160 eV photon energy, a windowless vuv-xuv beam line design is proposed

  6. EVOLUTIONARY FOUNDATIONS FOR MOLECULAR MEDICINE

    Science.gov (United States)

    Nesse, Randolph M.; Ganten, Detlev; Gregory, T. Ryan; Omenn, Gilbert S.

    2015-01-01

    Evolution has long provided a foundation for population genetics, but many major advances in evolutionary biology from the 20th century are only now being applied in molecular medicine. They include the distinction between proximate and evolutionary explanations, kin selection, evolutionary models for cooperation, and new strategies for tracing phylogenies and identifying signals of selection. Recent advances in genomics are further transforming evolutionary biology and creating yet more opportunities for progress at the interface of evolution with genetics, medicine, and public health. This article reviews 15 evolutionary principles and their applications in molecular medicine in hopes that readers will use them and others to speed the development of evolutionary molecular medicine. PMID:22544168

  7. Molecular thermodynamics of nonideal fluids

    CERN Document Server

    Lee, Lloyd L

    2013-01-01

    Molecular Thermodynamics of Nonideal Fluids serves as an introductory presentation for engineers to the concepts and principles behind and the advances in molecular thermodynamics of nonideal fluids. The book covers related topics such as the laws of thermodynamics; entropy; its ensembles; the different properties of the ideal gas; and the structure of liquids. Also covered in the book are topics such as integral equation theories; theories for polar fluids; solution thermodynamics; and molecular dynamics. The text is recommended for engineers who would like to be familiarized with the concept

  8. Metrological issues in molecular radiotherapy

    International Nuclear Information System (INIS)

    D'Arienzo, Marco; Capogni, Marco; Smyth, Vere; Cox, Maurice; Johansson, Lena; Bobin, Christophe

    2014-01-01

    The therapeutic effect from molecular radiation therapy (MRT), on both tumour and normal tissue, is determined by the radiation absorbed dose. Recent research indicates that as a consequence of biological variation across patients the absorbed dose can vary, for the same administered activity, by as much as two orders of magnitude. The international collaborative EURAMET-EMRP project Metrology for molecular radiotherapy (MetroMRT) is addressing this problem. The overall aim of the project is to develop methods of calibrating and verifying clinical dosimetry in MRT. In the present paper an overview of the metrological issues in molecular radiotherapy is provided. (authors)

  9. NASA Applications of Molecular Nanotechnology

    Science.gov (United States)

    Globus, Al; Bailey, David; Han, Jie; Jaffe, Richard; Levit, Creon; Merkle, Ralph; Srivastava, Deepak

    1998-01-01

    Laboratories throughout the world are rapidly gaining atomically precise control over matter. As this control extends to an ever wider variety of materials, processes and devices, opportunities for applications relevant to NASA's missions will be created. This document surveys a number of future molecular nanotechnology capabilities of aerospace interest. Computer applications, launch vehicle improvements, and active materials appear to be of particular interest. We also list a number of applications for each of NASA's enterprises. If advanced molecular nanotechnology can be developed, almost all of NASA's endeavors will be radically improved. In particular, a sufficiently advanced molecular nanotechnology can arguably bring large scale space colonization within our grasp.

  10. Exercises in molecular computing.

    Science.gov (United States)

    Stojanovic, Milan N; Stefanovic, Darko; Rudchenko, Sergei

    2014-06-17

    CONSPECTUS: The successes of electronic digital logic have transformed every aspect of human life over the last half-century. The word "computer" now signifies a ubiquitous electronic device, rather than a human occupation. Yet evidently humans, large assemblies of molecules, can compute, and it has been a thrilling challenge to develop smaller, simpler, synthetic assemblies of molecules that can do useful computation. When we say that molecules compute, what we usually mean is that such molecules respond to certain inputs, for example, the presence or absence of other molecules, in a precisely defined but potentially complex fashion. The simplest way for a chemist to think about computing molecules is as sensors that can integrate the presence or absence of multiple analytes into a change in a single reporting property. Here we review several forms of molecular computing developed in our laboratories. When we began our work, combinatorial approaches to using DNA for computing were used to search for solutions to constraint satisfaction problems. We chose to work instead on logic circuits, building bottom-up from units based on catalytic nucleic acids, focusing on DNA secondary structures in the design of individual circuit elements, and reserving the combinatorial opportunities of DNA for the representation of multiple signals propagating in a large circuit. Such circuit design directly corresponds to the intuition about sensors transforming the detection of analytes into reporting properties. While this approach was unusual at the time, it has been adopted since by other groups working on biomolecular computing with different nucleic acid chemistries. We created logic gates by modularly combining deoxyribozymes (DNA-based enzymes cleaving or combining other oligonucleotides), in the role of reporting elements, with stem-loops as input detection elements. For instance, a deoxyribozyme that normally exhibits an oligonucleotide substrate recognition region is

  11. Molecular control of rodent spermatogenesis

    NARCIS (Netherlands)

    Jan, Sabrina Z.; Hamer, Geert; Repping, Sjoerd; de Rooij, Dirk G.; van Pelt, Ans M. M.; Vormer, Tinke L.

    2012-01-01

    Spermatogenesis is a complex developmental process that ultimately generates mature spermatozoa. This process involves a phase of proliferative expansion, meiosis, and cytodifferentiation. Mouse models have been widely used to study spermatogenesis and have revealed many genes and molecular

  12. Transport properties of molecular junctions

    CERN Document Server

    Zimbovskaya, Natalya A

    2013-01-01

    A comprehensive overview of the physical mechanisms that control electron transport and the characteristics of metal-molecule-metal (MMM) junctions is presented. As far as possible, methods and formalisms presented elsewhere to analyze electron transport through molecules are avoided. This title introduces basic concepts—a description of the electron transport through molecular junctions—and briefly describes relevant experimental methods. Theoretical methods commonly used to analyze the electron transport through molecules are presented. Various effects that manifest in the electron transport through MMMs, as well as the basics of density-functional theory and its applications to electronic structure calculations in molecules are presented. Nanoelectronic applications of molecular junctions and similar systems are discussed as well. Molecular electronics is a diverse and rapidly growing field. Transport Properties of Molecular Junctions presents an up-to-date survey of the field suitable for researchers ...

  13. Microfluidic technology for molecular diagnostics.

    Science.gov (United States)

    Robinson, Tom; Dittrich, Petra S

    2013-01-01

    Molecular diagnostics have helped to improve the lives of millions of patients worldwide by allowing clinicians to diagnose patients earlier as well as providing better ongoing therapies. Point-of-care (POC) testing can bring these laboratory-based techniques to the patient in a home setting or to remote settings in the developing world. However, despite substantial progress in the field, there still remain many challenges. Progress in molecular diagnostics has benefitted greatly from microfluidic technology. This chapter aims to summarise the more recent advances in microfluidic-based molecular diagnostics. Sections include an introduction to microfluidic technology, the challenges of molecular diagnostics, how microfluidic advances are working to solve these issues, some alternative design approaches, and detection within these systems.

  14. Black Sprayable Molecular Adsorber Coating

    Data.gov (United States)

    National Aeronautics and Space Administration — The main objective of this technology project is to develop, optimize, and flight qualify a black version of the molecular adsorber coating and a conductive version...

  15. Physical adsorption and molecular dynamics

    International Nuclear Information System (INIS)

    Cohan, N.V.

    1981-01-01

    Some aspects of noble gases adsorption (except He) on graphite substracts are reviewed. Experimental results from this adsorption are analyzed and compared with molecular dynamics calculations. (L.C.) [pt

  16. Molecular Biomedical Imaging Laboratory (MBIL)

    Data.gov (United States)

    Federal Laboratory Consortium — The Molecular Biomedical Imaging Laboratory (MBIL) is adjacent-a nd has access-to the Department of Radiology and Imaging Sciences clinical imaging facilities. MBIL...

  17. Computer representation of molecular surfaces

    International Nuclear Information System (INIS)

    Max, N.L.

    1981-01-01

    This review article surveys recent work on computer representation of molecular surfaces. Several different algorithms are discussed for producing vector or raster drawings of space-filling models formed as the union of spheres. Other smoother surfaces are also considered

  18. Physical chemistry: Molecular motion watched

    Science.gov (United States)

    Siwick, Bradley; Collet, Eric

    2013-04-01

    A laser pulse can switch certain crystals from an insulating phase to a highly conducting phase. The ultrafast molecular motions that drive the transition have been directly observed using electron diffraction. See Letter p.343

  19. The molecular basis of radiosensitivity

    International Nuclear Information System (INIS)

    McMillan, T.J.

    1989-01-01

    This paper considers how DNA damage induced by ionising radiation is processed within the cell. The current view of radiobiology is discussed. The author explains the molecular processes that underlie the differences in radiosensitivity

  20. EAACI Molecular Allergology User's Guide

    NARCIS (Netherlands)

    Matricardi, P. M.; Kleine-Tebbe, J.; Hoffmann, H. J.; Valenta, R.; Hilger, C.; Hofmaier, S.; Aalberse, R. C.; Agache, I.; Asero, R.; Ballmer-Weber, B.; Barber, D.; Beyer, K.; Biedermann, T.; Bilò, M. B.; Blank, S.; Bohle, B.; Bosshard, P. P.; Breiteneder, H.; Brough, H. A.; Caraballo, L.; Caubet, J. C.; Crameri, R.; Davies, J. M.; Douladiris, N.; Ebisawa, M.; EIgenmann, P. A.; Fernandez-Rivas, M.; Ferreira, F.; Gadermaier, G.; Glatz, M.; Hamilton, R. G.; Hawranek, T.; Hellings, P.; Hoffmann-Sommergruber, K.; Jakob, T.; Jappe, U.; Jutel, M.; Kamath, S. D.; Knol, E. F.; Korosec, P.; Kuehn, A.; Lack, G.; Lopata, A. L.; Mäkelä, M.; Morisset, M.; Niederberger, V.; Nowak-Węgrzyn, A. H.; Papadopoulos, N. G.; Pastorello, E. A.; Pauli, G.; Platts-Mills, T.; Posa, D.; Poulsen, L. K.; Raulf, M.; Sastre, J.; Scala, E.; Schmid, J. M.; Schmid-Grendelmeier, P.; van Hage, M.; van Ree, R.; Vieths, S.; Weber, R.; Wickman, M.; Muraro, A.; Ollert, M.

    2016-01-01

    The availability of allergen molecules ('components') from several protein families has advanced our understanding of immunoglobulin E (IgE)-mediated responses and enabled 'component-resolved diagnosis' (CRD). The European Academy of Allergy and Clinical Immunology (EAACI) Molecular Allergology